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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Driver for msm7k serial device and console
   4 *
   5 * Copyright (C) 2007 Google, Inc.
   6 * Author: Robert Love <rlove@google.com>
   7 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
 
 
 
 
 
 
 
 
 
   8 */
   9
  10#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  11# define SUPPORT_SYSRQ
  12#endif
  13
  14#include <linux/kernel.h>
  15#include <linux/atomic.h>
  16#include <linux/dma-mapping.h>
  17#include <linux/dmaengine.h>
  18#include <linux/module.h>
  19#include <linux/io.h>
  20#include <linux/ioport.h>
  21#include <linux/interrupt.h>
  22#include <linux/init.h>
  23#include <linux/console.h>
  24#include <linux/tty.h>
  25#include <linux/tty_flip.h>
  26#include <linux/serial_core.h>
  27#include <linux/slab.h>
  28#include <linux/clk.h>
  29#include <linux/platform_device.h>
  30#include <linux/delay.h>
  31#include <linux/of.h>
  32#include <linux/of_device.h>
  33#include <linux/wait.h>
  34
  35#define UART_MR1			0x0000
  36
  37#define UART_MR1_AUTO_RFR_LEVEL0	0x3F
  38#define UART_MR1_AUTO_RFR_LEVEL1	0x3FF00
  39#define UART_DM_MR1_AUTO_RFR_LEVEL1	0xFFFFFF00
  40#define UART_MR1_RX_RDY_CTL		BIT(7)
  41#define UART_MR1_CTS_CTL		BIT(6)
  42
  43#define UART_MR2			0x0004
  44#define UART_MR2_ERROR_MODE		BIT(6)
  45#define UART_MR2_BITS_PER_CHAR		0x30
  46#define UART_MR2_BITS_PER_CHAR_5	(0x0 << 4)
  47#define UART_MR2_BITS_PER_CHAR_6	(0x1 << 4)
  48#define UART_MR2_BITS_PER_CHAR_7	(0x2 << 4)
  49#define UART_MR2_BITS_PER_CHAR_8	(0x3 << 4)
  50#define UART_MR2_STOP_BIT_LEN_ONE	(0x1 << 2)
  51#define UART_MR2_STOP_BIT_LEN_TWO	(0x3 << 2)
  52#define UART_MR2_PARITY_MODE_NONE	0x0
  53#define UART_MR2_PARITY_MODE_ODD	0x1
  54#define UART_MR2_PARITY_MODE_EVEN	0x2
  55#define UART_MR2_PARITY_MODE_SPACE	0x3
  56#define UART_MR2_PARITY_MODE		0x3
  57
  58#define UART_CSR			0x0008
  59
  60#define UART_TF				0x000C
  61#define UARTDM_TF			0x0070
  62
  63#define UART_CR				0x0010
  64#define UART_CR_CMD_NULL		(0 << 4)
  65#define UART_CR_CMD_RESET_RX		(1 << 4)
  66#define UART_CR_CMD_RESET_TX		(2 << 4)
  67#define UART_CR_CMD_RESET_ERR		(3 << 4)
  68#define UART_CR_CMD_RESET_BREAK_INT	(4 << 4)
  69#define UART_CR_CMD_START_BREAK		(5 << 4)
  70#define UART_CR_CMD_STOP_BREAK		(6 << 4)
  71#define UART_CR_CMD_RESET_CTS		(7 << 4)
  72#define UART_CR_CMD_RESET_STALE_INT	(8 << 4)
  73#define UART_CR_CMD_PACKET_MODE		(9 << 4)
  74#define UART_CR_CMD_MODE_RESET		(12 << 4)
  75#define UART_CR_CMD_SET_RFR		(13 << 4)
  76#define UART_CR_CMD_RESET_RFR		(14 << 4)
  77#define UART_CR_CMD_PROTECTION_EN	(16 << 4)
  78#define UART_CR_CMD_STALE_EVENT_DISABLE	(6 << 8)
  79#define UART_CR_CMD_STALE_EVENT_ENABLE	(80 << 4)
  80#define UART_CR_CMD_FORCE_STALE		(4 << 8)
  81#define UART_CR_CMD_RESET_TX_READY	(3 << 8)
  82#define UART_CR_TX_DISABLE		BIT(3)
  83#define UART_CR_TX_ENABLE		BIT(2)
  84#define UART_CR_RX_DISABLE		BIT(1)
  85#define UART_CR_RX_ENABLE		BIT(0)
  86#define UART_CR_CMD_RESET_RXBREAK_START	((1 << 11) | (2 << 4))
  87
  88#define UART_IMR			0x0014
  89#define UART_IMR_TXLEV			BIT(0)
  90#define UART_IMR_RXSTALE		BIT(3)
  91#define UART_IMR_RXLEV			BIT(4)
  92#define UART_IMR_DELTA_CTS		BIT(5)
  93#define UART_IMR_CURRENT_CTS		BIT(6)
  94#define UART_IMR_RXBREAK_START		BIT(10)
  95
  96#define UART_IPR_RXSTALE_LAST		0x20
  97#define UART_IPR_STALE_LSB		0x1F
  98#define UART_IPR_STALE_TIMEOUT_MSB	0x3FF80
  99#define UART_DM_IPR_STALE_TIMEOUT_MSB	0xFFFFFF80
 100
 101#define UART_IPR			0x0018
 102#define UART_TFWR			0x001C
 103#define UART_RFWR			0x0020
 104#define UART_HCR			0x0024
 105
 106#define UART_MREG			0x0028
 107#define UART_NREG			0x002C
 108#define UART_DREG			0x0030
 109#define UART_MNDREG			0x0034
 110#define UART_IRDA			0x0038
 111#define UART_MISR_MODE			0x0040
 112#define UART_MISR_RESET			0x0044
 113#define UART_MISR_EXPORT		0x0048
 114#define UART_MISR_VAL			0x004C
 115#define UART_TEST_CTRL			0x0050
 116
 117#define UART_SR				0x0008
 118#define UART_SR_HUNT_CHAR		BIT(7)
 119#define UART_SR_RX_BREAK		BIT(6)
 120#define UART_SR_PAR_FRAME_ERR		BIT(5)
 121#define UART_SR_OVERRUN			BIT(4)
 122#define UART_SR_TX_EMPTY		BIT(3)
 123#define UART_SR_TX_READY		BIT(2)
 124#define UART_SR_RX_FULL			BIT(1)
 125#define UART_SR_RX_READY		BIT(0)
 126
 127#define UART_RF				0x000C
 128#define UARTDM_RF			0x0070
 129#define UART_MISR			0x0010
 130#define UART_ISR			0x0014
 131#define UART_ISR_TX_READY		BIT(7)
 132
 133#define UARTDM_RXFS			0x50
 134#define UARTDM_RXFS_BUF_SHIFT		0x7
 135#define UARTDM_RXFS_BUF_MASK		0x7
 136
 137#define UARTDM_DMEN			0x3C
 138#define UARTDM_DMEN_RX_SC_ENABLE	BIT(5)
 139#define UARTDM_DMEN_TX_SC_ENABLE	BIT(4)
 140
 141#define UARTDM_DMEN_TX_BAM_ENABLE	BIT(2)	/* UARTDM_1P4 */
 142#define UARTDM_DMEN_TX_DM_ENABLE	BIT(0)	/* < UARTDM_1P4 */
 143
 144#define UARTDM_DMEN_RX_BAM_ENABLE	BIT(3)	/* UARTDM_1P4 */
 145#define UARTDM_DMEN_RX_DM_ENABLE	BIT(1)	/* < UARTDM_1P4 */
 146
 147#define UARTDM_DMRX			0x34
 148#define UARTDM_NCF_TX			0x40
 149#define UARTDM_RX_TOTAL_SNAP		0x38
 150
 151#define UARTDM_BURST_SIZE		16   /* in bytes */
 152#define UARTDM_TX_AIGN(x)		((x) & ~0x3) /* valid for > 1p3 */
 153#define UARTDM_TX_MAX			256   /* in bytes, valid for <= 1p3 */
 154#define UARTDM_RX_SIZE			(UART_XMIT_SIZE / 4)
 155
 156enum {
 157	UARTDM_1P1 = 1,
 158	UARTDM_1P2,
 159	UARTDM_1P3,
 160	UARTDM_1P4,
 161};
 162
 163struct msm_dma {
 164	struct dma_chan		*chan;
 165	enum dma_data_direction dir;
 166	dma_addr_t		phys;
 167	unsigned char		*virt;
 168	dma_cookie_t		cookie;
 169	u32			enable_bit;
 170	unsigned int		count;
 171	struct dma_async_tx_descriptor	*desc;
 172};
 173
 174struct msm_port {
 175	struct uart_port	uart;
 176	char			name[16];
 177	struct clk		*clk;
 178	struct clk		*pclk;
 179	unsigned int		imr;
 
 180	int			is_uartdm;
 181	unsigned int		old_snap_state;
 182	bool			break_detected;
 183	struct msm_dma		tx_dma;
 184	struct msm_dma		rx_dma;
 185};
 186
 187#define UART_TO_MSM(uart_port)	container_of(uart_port, struct msm_port, uart)
 188
 189static
 190void msm_write(struct uart_port *port, unsigned int val, unsigned int off)
 191{
 192	writel_relaxed(val, port->membase + off);
 193}
 194
 195static
 196unsigned int msm_read(struct uart_port *port, unsigned int off)
 197{
 198	return readl_relaxed(port->membase + off);
 199}
 200
 201/*
 202 * Setup the MND registers to use the TCXO clock.
 203 */
 204static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port)
 205{
 206	msm_write(port, 0x06, UART_MREG);
 207	msm_write(port, 0xF1, UART_NREG);
 208	msm_write(port, 0x0F, UART_DREG);
 209	msm_write(port, 0x1A, UART_MNDREG);
 210	port->uartclk = 1843200;
 211}
 212
 213/*
 214 * Setup the MND registers to use the TCXO clock divided by 4.
 215 */
 216static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port)
 217{
 218	msm_write(port, 0x18, UART_MREG);
 219	msm_write(port, 0xF6, UART_NREG);
 220	msm_write(port, 0x0F, UART_DREG);
 221	msm_write(port, 0x0A, UART_MNDREG);
 222	port->uartclk = 1843200;
 223}
 224
 225static void msm_serial_set_mnd_regs(struct uart_port *port)
 226{
 227	struct msm_port *msm_port = UART_TO_MSM(port);
 228
 229	/*
 230	 * These registers don't exist so we change the clk input rate
 231	 * on uartdm hardware instead
 232	 */
 233	if (msm_port->is_uartdm)
 234		return;
 235
 236	if (port->uartclk == 19200000)
 237		msm_serial_set_mnd_regs_tcxo(port);
 238	else if (port->uartclk == 4800000)
 239		msm_serial_set_mnd_regs_tcxoby4(port);
 240}
 241
 242static void msm_handle_tx(struct uart_port *port);
 243static void msm_start_rx_dma(struct msm_port *msm_port);
 244
 245static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma)
 246{
 247	struct device *dev = port->dev;
 248	unsigned int mapped;
 249	u32 val;
 250
 251	mapped = dma->count;
 252	dma->count = 0;
 253
 254	dmaengine_terminate_all(dma->chan);
 255
 256	/*
 257	 * DMA Stall happens if enqueue and flush command happens concurrently.
 258	 * For example before changing the baud rate/protocol configuration and
 259	 * sending flush command to ADM, disable the channel of UARTDM.
 260	 * Note: should not reset the receiver here immediately as it is not
 261	 * suggested to do disable/reset or reset/disable at the same time.
 262	 */
 263	val = msm_read(port, UARTDM_DMEN);
 264	val &= ~dma->enable_bit;
 265	msm_write(port, val, UARTDM_DMEN);
 266
 267	if (mapped)
 268		dma_unmap_single(dev, dma->phys, mapped, dma->dir);
 269}
 270
 271static void msm_release_dma(struct msm_port *msm_port)
 272{
 273	struct msm_dma *dma;
 274
 275	dma = &msm_port->tx_dma;
 276	if (dma->chan) {
 277		msm_stop_dma(&msm_port->uart, dma);
 278		dma_release_channel(dma->chan);
 279	}
 280
 281	memset(dma, 0, sizeof(*dma));
 282
 283	dma = &msm_port->rx_dma;
 284	if (dma->chan) {
 285		msm_stop_dma(&msm_port->uart, dma);
 286		dma_release_channel(dma->chan);
 287		kfree(dma->virt);
 288	}
 289
 290	memset(dma, 0, sizeof(*dma));
 291}
 292
 293static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base)
 294{
 295	struct device *dev = msm_port->uart.dev;
 296	struct dma_slave_config conf;
 297	struct msm_dma *dma;
 298	u32 crci = 0;
 299	int ret;
 300
 301	dma = &msm_port->tx_dma;
 302
 303	/* allocate DMA resources, if available */
 304	dma->chan = dma_request_slave_channel_reason(dev, "tx");
 305	if (IS_ERR(dma->chan))
 306		goto no_tx;
 307
 308	of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci);
 309
 310	memset(&conf, 0, sizeof(conf));
 311	conf.direction = DMA_MEM_TO_DEV;
 312	conf.device_fc = true;
 313	conf.dst_addr = base + UARTDM_TF;
 314	conf.dst_maxburst = UARTDM_BURST_SIZE;
 315	conf.slave_id = crci;
 316
 317	ret = dmaengine_slave_config(dma->chan, &conf);
 318	if (ret)
 319		goto rel_tx;
 320
 321	dma->dir = DMA_TO_DEVICE;
 322
 323	if (msm_port->is_uartdm < UARTDM_1P4)
 324		dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE;
 325	else
 326		dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE;
 327
 328	return;
 329
 330rel_tx:
 331	dma_release_channel(dma->chan);
 332no_tx:
 333	memset(dma, 0, sizeof(*dma));
 334}
 335
 336static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base)
 337{
 338	struct device *dev = msm_port->uart.dev;
 339	struct dma_slave_config conf;
 340	struct msm_dma *dma;
 341	u32 crci = 0;
 342	int ret;
 343
 344	dma = &msm_port->rx_dma;
 345
 346	/* allocate DMA resources, if available */
 347	dma->chan = dma_request_slave_channel_reason(dev, "rx");
 348	if (IS_ERR(dma->chan))
 349		goto no_rx;
 350
 351	of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci);
 352
 353	dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL);
 354	if (!dma->virt)
 355		goto rel_rx;
 356
 357	memset(&conf, 0, sizeof(conf));
 358	conf.direction = DMA_DEV_TO_MEM;
 359	conf.device_fc = true;
 360	conf.src_addr = base + UARTDM_RF;
 361	conf.src_maxburst = UARTDM_BURST_SIZE;
 362	conf.slave_id = crci;
 363
 364	ret = dmaengine_slave_config(dma->chan, &conf);
 365	if (ret)
 366		goto err;
 367
 368	dma->dir = DMA_FROM_DEVICE;
 369
 370	if (msm_port->is_uartdm < UARTDM_1P4)
 371		dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE;
 372	else
 373		dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE;
 374
 375	return;
 376err:
 377	kfree(dma->virt);
 378rel_rx:
 379	dma_release_channel(dma->chan);
 380no_rx:
 381	memset(dma, 0, sizeof(*dma));
 382}
 383
 384static inline void msm_wait_for_xmitr(struct uart_port *port)
 385{
 386	unsigned int timeout = 500000;
 387
 388	while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) {
 389		if (msm_read(port, UART_ISR) & UART_ISR_TX_READY)
 390			break;
 391		udelay(1);
 392		if (!timeout--)
 393			break;
 394	}
 395	msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR);
 396}
 397
 398static void msm_stop_tx(struct uart_port *port)
 399{
 400	struct msm_port *msm_port = UART_TO_MSM(port);
 401
 402	msm_port->imr &= ~UART_IMR_TXLEV;
 403	msm_write(port, msm_port->imr, UART_IMR);
 404}
 405
 406static void msm_start_tx(struct uart_port *port)
 407{
 408	struct msm_port *msm_port = UART_TO_MSM(port);
 409	struct msm_dma *dma = &msm_port->tx_dma;
 410
 411	/* Already started in DMA mode */
 412	if (dma->count)
 413		return;
 414
 415	msm_port->imr |= UART_IMR_TXLEV;
 416	msm_write(port, msm_port->imr, UART_IMR);
 417}
 418
 419static void msm_reset_dm_count(struct uart_port *port, int count)
 420{
 421	msm_wait_for_xmitr(port);
 422	msm_write(port, count, UARTDM_NCF_TX);
 423	msm_read(port, UARTDM_NCF_TX);
 424}
 425
 426static void msm_complete_tx_dma(void *args)
 427{
 428	struct msm_port *msm_port = args;
 429	struct uart_port *port = &msm_port->uart;
 430	struct circ_buf *xmit = &port->state->xmit;
 431	struct msm_dma *dma = &msm_port->tx_dma;
 432	struct dma_tx_state state;
 433	enum dma_status status;
 434	unsigned long flags;
 435	unsigned int count;
 436	u32 val;
 437
 438	spin_lock_irqsave(&port->lock, flags);
 439
 440	/* Already stopped */
 441	if (!dma->count)
 442		goto done;
 443
 444	status = dmaengine_tx_status(dma->chan, dma->cookie, &state);
 445
 446	dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir);
 447
 448	val = msm_read(port, UARTDM_DMEN);
 449	val &= ~dma->enable_bit;
 450	msm_write(port, val, UARTDM_DMEN);
 451
 452	if (msm_port->is_uartdm > UARTDM_1P3) {
 453		msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
 454		msm_write(port, UART_CR_TX_ENABLE, UART_CR);
 455	}
 456
 457	count = dma->count - state.residue;
 458	port->icount.tx += count;
 459	dma->count = 0;
 460
 461	xmit->tail += count;
 462	xmit->tail &= UART_XMIT_SIZE - 1;
 463
 464	/* Restore "Tx FIFO below watermark" interrupt */
 465	msm_port->imr |= UART_IMR_TXLEV;
 466	msm_write(port, msm_port->imr, UART_IMR);
 467
 468	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 469		uart_write_wakeup(port);
 470
 471	msm_handle_tx(port);
 472done:
 473	spin_unlock_irqrestore(&port->lock, flags);
 474}
 475
 476static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
 477{
 478	struct circ_buf *xmit = &msm_port->uart.state->xmit;
 479	struct uart_port *port = &msm_port->uart;
 480	struct msm_dma *dma = &msm_port->tx_dma;
 481	void *cpu_addr;
 482	int ret;
 483	u32 val;
 484
 485	cpu_addr = &xmit->buf[xmit->tail];
 486
 487	dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir);
 488	ret = dma_mapping_error(port->dev, dma->phys);
 489	if (ret)
 490		return ret;
 491
 492	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
 493						count, DMA_MEM_TO_DEV,
 494						DMA_PREP_INTERRUPT |
 495						DMA_PREP_FENCE);
 496	if (!dma->desc) {
 497		ret = -EIO;
 498		goto unmap;
 499	}
 500
 501	dma->desc->callback = msm_complete_tx_dma;
 502	dma->desc->callback_param = msm_port;
 503
 504	dma->cookie = dmaengine_submit(dma->desc);
 505	ret = dma_submit_error(dma->cookie);
 506	if (ret)
 507		goto unmap;
 508
 509	/*
 510	 * Using DMA complete for Tx FIFO reload, no need for
 511	 * "Tx FIFO below watermark" one, disable it
 512	 */
 513	msm_port->imr &= ~UART_IMR_TXLEV;
 514	msm_write(port, msm_port->imr, UART_IMR);
 515
 516	dma->count = count;
 517
 518	val = msm_read(port, UARTDM_DMEN);
 519	val |= dma->enable_bit;
 520
 521	if (msm_port->is_uartdm < UARTDM_1P4)
 522		msm_write(port, val, UARTDM_DMEN);
 523
 524	msm_reset_dm_count(port, count);
 525
 526	if (msm_port->is_uartdm > UARTDM_1P3)
 527		msm_write(port, val, UARTDM_DMEN);
 528
 529	dma_async_issue_pending(dma->chan);
 530	return 0;
 531unmap:
 532	dma_unmap_single(port->dev, dma->phys, count, dma->dir);
 533	return ret;
 534}
 535
 536static void msm_complete_rx_dma(void *args)
 537{
 538	struct msm_port *msm_port = args;
 539	struct uart_port *port = &msm_port->uart;
 540	struct tty_port *tport = &port->state->port;
 541	struct msm_dma *dma = &msm_port->rx_dma;
 542	int count = 0, i, sysrq;
 543	unsigned long flags;
 544	u32 val;
 545
 546	spin_lock_irqsave(&port->lock, flags);
 547
 548	/* Already stopped */
 549	if (!dma->count)
 550		goto done;
 551
 552	val = msm_read(port, UARTDM_DMEN);
 553	val &= ~dma->enable_bit;
 554	msm_write(port, val, UARTDM_DMEN);
 555
 556	if (msm_read(port, UART_SR) & UART_SR_OVERRUN) {
 557		port->icount.overrun++;
 558		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 559		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 560	}
 561
 562	count = msm_read(port, UARTDM_RX_TOTAL_SNAP);
 563
 564	port->icount.rx += count;
 565
 566	dma->count = 0;
 567
 568	dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
 569
 570	for (i = 0; i < count; i++) {
 571		char flag = TTY_NORMAL;
 572
 573		if (msm_port->break_detected && dma->virt[i] == 0) {
 574			port->icount.brk++;
 575			flag = TTY_BREAK;
 576			msm_port->break_detected = false;
 577			if (uart_handle_break(port))
 578				continue;
 579		}
 580
 581		if (!(port->read_status_mask & UART_SR_RX_BREAK))
 582			flag = TTY_NORMAL;
 583
 584		spin_unlock_irqrestore(&port->lock, flags);
 585		sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
 586		spin_lock_irqsave(&port->lock, flags);
 587		if (!sysrq)
 588			tty_insert_flip_char(tport, dma->virt[i], flag);
 589	}
 590
 591	msm_start_rx_dma(msm_port);
 592done:
 593	spin_unlock_irqrestore(&port->lock, flags);
 594
 595	if (count)
 596		tty_flip_buffer_push(tport);
 597}
 598
 599static void msm_start_rx_dma(struct msm_port *msm_port)
 600{
 601	struct msm_dma *dma = &msm_port->rx_dma;
 602	struct uart_port *uart = &msm_port->uart;
 603	u32 val;
 604	int ret;
 605
 606	if (!dma->chan)
 607		return;
 608
 609	dma->phys = dma_map_single(uart->dev, dma->virt,
 610				   UARTDM_RX_SIZE, dma->dir);
 611	ret = dma_mapping_error(uart->dev, dma->phys);
 612	if (ret)
 613		return;
 614
 615	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
 616						UARTDM_RX_SIZE, DMA_DEV_TO_MEM,
 617						DMA_PREP_INTERRUPT);
 618	if (!dma->desc)
 619		goto unmap;
 620
 621	dma->desc->callback = msm_complete_rx_dma;
 622	dma->desc->callback_param = msm_port;
 623
 624	dma->cookie = dmaengine_submit(dma->desc);
 625	ret = dma_submit_error(dma->cookie);
 626	if (ret)
 627		goto unmap;
 628	/*
 629	 * Using DMA for FIFO off-load, no need for "Rx FIFO over
 630	 * watermark" or "stale" interrupts, disable them
 631	 */
 632	msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
 633
 634	/*
 635	 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3),
 636	 * we need RXSTALE to flush input DMA fifo to memory
 637	 */
 638	if (msm_port->is_uartdm < UARTDM_1P4)
 639		msm_port->imr |= UART_IMR_RXSTALE;
 640
 641	msm_write(uart, msm_port->imr, UART_IMR);
 642
 643	dma->count = UARTDM_RX_SIZE;
 644
 645	dma_async_issue_pending(dma->chan);
 646
 647	msm_write(uart, UART_CR_CMD_RESET_STALE_INT, UART_CR);
 648	msm_write(uart, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
 649
 650	val = msm_read(uart, UARTDM_DMEN);
 651	val |= dma->enable_bit;
 652
 653	if (msm_port->is_uartdm < UARTDM_1P4)
 654		msm_write(uart, val, UARTDM_DMEN);
 655
 656	msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX);
 657
 658	if (msm_port->is_uartdm > UARTDM_1P3)
 659		msm_write(uart, val, UARTDM_DMEN);
 660
 661	return;
 662unmap:
 663	dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
 664}
 665
 666static void msm_stop_rx(struct uart_port *port)
 667{
 668	struct msm_port *msm_port = UART_TO_MSM(port);
 669	struct msm_dma *dma = &msm_port->rx_dma;
 670
 671	msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
 672	msm_write(port, msm_port->imr, UART_IMR);
 673
 674	if (dma->chan)
 675		msm_stop_dma(port, dma);
 676}
 677
 678static void msm_enable_ms(struct uart_port *port)
 679{
 680	struct msm_port *msm_port = UART_TO_MSM(port);
 681
 682	msm_port->imr |= UART_IMR_DELTA_CTS;
 683	msm_write(port, msm_port->imr, UART_IMR);
 684}
 685
 686static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
 687{
 688	struct tty_port *tport = &port->state->port;
 689	unsigned int sr;
 690	int count = 0;
 691	struct msm_port *msm_port = UART_TO_MSM(port);
 692
 693	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
 694		port->icount.overrun++;
 695		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 696		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 697	}
 698
 699	if (misr & UART_IMR_RXSTALE) {
 700		count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
 701			msm_port->old_snap_state;
 702		msm_port->old_snap_state = 0;
 703	} else {
 704		count = 4 * (msm_read(port, UART_RFWR));
 705		msm_port->old_snap_state += count;
 706	}
 707
 708	/* TODO: Precise error reporting */
 709
 710	port->icount.rx += count;
 711
 712	while (count > 0) {
 713		unsigned char buf[4];
 714		int sysrq, r_count, i;
 715
 716		sr = msm_read(port, UART_SR);
 717		if ((sr & UART_SR_RX_READY) == 0) {
 718			msm_port->old_snap_state -= count;
 719			break;
 720		}
 
 
 
 
 
 
 
 721
 722		ioread32_rep(port->membase + UARTDM_RF, buf, 1);
 723		r_count = min_t(int, count, sizeof(buf));
 724
 725		for (i = 0; i < r_count; i++) {
 726			char flag = TTY_NORMAL;
 727
 728			if (msm_port->break_detected && buf[i] == 0) {
 729				port->icount.brk++;
 730				flag = TTY_BREAK;
 731				msm_port->break_detected = false;
 732				if (uart_handle_break(port))
 733					continue;
 734			}
 735
 736			if (!(port->read_status_mask & UART_SR_RX_BREAK))
 737				flag = TTY_NORMAL;
 738
 739			spin_unlock(&port->lock);
 740			sysrq = uart_handle_sysrq_char(port, buf[i]);
 741			spin_lock(&port->lock);
 742			if (!sysrq)
 743				tty_insert_flip_char(tport, buf[i], flag);
 744		}
 745		count -= r_count;
 746	}
 747
 748	spin_unlock(&port->lock);
 749	tty_flip_buffer_push(tport);
 750	spin_lock(&port->lock);
 751
 752	if (misr & (UART_IMR_RXSTALE))
 753		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
 754	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
 755	msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
 756
 757	/* Try to use DMA */
 758	msm_start_rx_dma(msm_port);
 759}
 760
 761static void msm_handle_rx(struct uart_port *port)
 762{
 763	struct tty_port *tport = &port->state->port;
 764	unsigned int sr;
 765
 766	/*
 767	 * Handle overrun. My understanding of the hardware is that overrun
 768	 * is not tied to the RX buffer, so we handle the case out of band.
 769	 */
 770	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
 771		port->icount.overrun++;
 772		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 773		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 774	}
 775
 776	/* and now the main RX loop */
 777	while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
 778		unsigned int c;
 779		char flag = TTY_NORMAL;
 780		int sysrq;
 781
 782		c = msm_read(port, UART_RF);
 783
 784		if (sr & UART_SR_RX_BREAK) {
 785			port->icount.brk++;
 786			if (uart_handle_break(port))
 787				continue;
 788		} else if (sr & UART_SR_PAR_FRAME_ERR) {
 789			port->icount.frame++;
 790		} else {
 791			port->icount.rx++;
 792		}
 793
 794		/* Mask conditions we're ignorning. */
 795		sr &= port->read_status_mask;
 796
 797		if (sr & UART_SR_RX_BREAK)
 798			flag = TTY_BREAK;
 799		else if (sr & UART_SR_PAR_FRAME_ERR)
 800			flag = TTY_FRAME;
 
 801
 802		spin_unlock(&port->lock);
 803		sysrq = uart_handle_sysrq_char(port, c);
 804		spin_lock(&port->lock);
 805		if (!sysrq)
 806			tty_insert_flip_char(tport, c, flag);
 807	}
 808
 809	spin_unlock(&port->lock);
 810	tty_flip_buffer_push(tport);
 811	spin_lock(&port->lock);
 812}
 813
 814static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count)
 
 
 
 
 
 
 
 815{
 816	struct circ_buf *xmit = &port->state->xmit;
 817	struct msm_port *msm_port = UART_TO_MSM(port);
 818	unsigned int num_chars;
 819	unsigned int tf_pointer = 0;
 820	void __iomem *tf;
 821
 822	if (msm_port->is_uartdm)
 823		tf = port->membase + UARTDM_TF;
 824	else
 825		tf = port->membase + UART_TF;
 826
 827	if (tx_count && msm_port->is_uartdm)
 828		msm_reset_dm_count(port, tx_count);
 
 
 
 
 
 
 
 
 
 829
 830	while (tf_pointer < tx_count) {
 831		int i;
 832		char buf[4] = { 0 };
 
 833
 834		if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 835			break;
 836
 837		if (msm_port->is_uartdm)
 838			num_chars = min(tx_count - tf_pointer,
 839					(unsigned int)sizeof(buf));
 840		else
 841			num_chars = 1;
 842
 843		for (i = 0; i < num_chars; i++) {
 844			buf[i] = xmit->buf[xmit->tail + i];
 845			port->icount.tx++;
 846		}
 847
 848		iowrite32_rep(tf, buf, 1);
 849		xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
 850		tf_pointer += num_chars;
 851	}
 852
 853	/* disable tx interrupts if nothing more to send */
 854	if (uart_circ_empty(xmit))
 855		msm_stop_tx(port);
 856
 857	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 858		uart_write_wakeup(port);
 859}
 860
 861static void msm_handle_tx(struct uart_port *port)
 862{
 863	struct msm_port *msm_port = UART_TO_MSM(port);
 864	struct circ_buf *xmit = &msm_port->uart.state->xmit;
 865	struct msm_dma *dma = &msm_port->tx_dma;
 866	unsigned int pio_count, dma_count, dma_min;
 867	char buf[4] = { 0 };
 868	void __iomem *tf;
 869	int err = 0;
 870
 871	if (port->x_char) {
 872		if (msm_port->is_uartdm)
 873			tf = port->membase + UARTDM_TF;
 874		else
 875			tf = port->membase + UART_TF;
 876
 877		buf[0] = port->x_char;
 878
 879		if (msm_port->is_uartdm)
 880			msm_reset_dm_count(port, 1);
 881
 882		iowrite32_rep(tf, buf, 1);
 883		port->icount.tx++;
 884		port->x_char = 0;
 885		return;
 886	}
 887
 888	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 889		msm_stop_tx(port);
 890		return;
 891	}
 892
 893	pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
 894	dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
 895
 896	dma_min = 1;	/* Always DMA */
 897	if (msm_port->is_uartdm > UARTDM_1P3) {
 898		dma_count = UARTDM_TX_AIGN(dma_count);
 899		dma_min = UARTDM_BURST_SIZE;
 900	} else {
 901		if (dma_count > UARTDM_TX_MAX)
 902			dma_count = UARTDM_TX_MAX;
 903	}
 904
 905	if (pio_count > port->fifosize)
 906		pio_count = port->fifosize;
 907
 908	if (!dma->chan || dma_count < dma_min)
 909		msm_handle_tx_pio(port, pio_count);
 910	else
 911		err = msm_handle_tx_dma(msm_port, dma_count);
 912
 913	if (err)	/* fall back to PIO mode */
 914		msm_handle_tx_pio(port, pio_count);
 915}
 916
 917static void msm_handle_delta_cts(struct uart_port *port)
 918{
 919	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
 920	port->icount.cts++;
 921	wake_up_interruptible(&port->state->port.delta_msr_wait);
 922}
 923
 924static irqreturn_t msm_uart_irq(int irq, void *dev_id)
 925{
 926	struct uart_port *port = dev_id;
 927	struct msm_port *msm_port = UART_TO_MSM(port);
 928	struct msm_dma *dma = &msm_port->rx_dma;
 929	unsigned long flags;
 930	unsigned int misr;
 931	u32 val;
 932
 933	spin_lock_irqsave(&port->lock, flags);
 934	misr = msm_read(port, UART_MISR);
 935	msm_write(port, 0, UART_IMR); /* disable interrupt */
 936
 937	if (misr & UART_IMR_RXBREAK_START) {
 938		msm_port->break_detected = true;
 939		msm_write(port, UART_CR_CMD_RESET_RXBREAK_START, UART_CR);
 940	}
 941
 942	if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) {
 943		if (dma->count) {
 944			val = UART_CR_CMD_STALE_EVENT_DISABLE;
 945			msm_write(port, val, UART_CR);
 946			val = UART_CR_CMD_RESET_STALE_INT;
 947			msm_write(port, val, UART_CR);
 948			/*
 949			 * Flush DMA input fifo to memory, this will also
 950			 * trigger DMA RX completion
 951			 */
 952			dmaengine_terminate_all(dma->chan);
 953		} else if (msm_port->is_uartdm) {
 954			msm_handle_rx_dm(port, misr);
 955		} else {
 956			msm_handle_rx(port);
 957		}
 958	}
 959	if (misr & UART_IMR_TXLEV)
 960		msm_handle_tx(port);
 961	if (misr & UART_IMR_DELTA_CTS)
 962		msm_handle_delta_cts(port);
 963
 964	msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
 965	spin_unlock_irqrestore(&port->lock, flags);
 966
 967	return IRQ_HANDLED;
 968}
 969
 970static unsigned int msm_tx_empty(struct uart_port *port)
 971{
 972	return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
 973}
 974
 975static unsigned int msm_get_mctrl(struct uart_port *port)
 976{
 977	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
 978}
 979
 
 980static void msm_reset(struct uart_port *port)
 981{
 982	struct msm_port *msm_port = UART_TO_MSM(port);
 983
 984	/* reset everything */
 985	msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
 986	msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
 987	msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 988	msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
 989	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
 990	msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
 991
 992	/* Disable DM modes */
 993	if (msm_port->is_uartdm)
 994		msm_write(port, 0, UARTDM_DMEN);
 995}
 996
 997static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
 998{
 999	unsigned int mr;
1000
1001	mr = msm_read(port, UART_MR1);
1002
1003	if (!(mctrl & TIOCM_RTS)) {
1004		mr &= ~UART_MR1_RX_RDY_CTL;
1005		msm_write(port, mr, UART_MR1);
1006		msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
1007	} else {
1008		mr |= UART_MR1_RX_RDY_CTL;
1009		msm_write(port, mr, UART_MR1);
1010	}
1011}
1012
1013static void msm_break_ctl(struct uart_port *port, int break_ctl)
1014{
1015	if (break_ctl)
1016		msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
1017	else
1018		msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
1019}
1020
1021struct msm_baud_map {
1022	u16	divisor;
1023	u8	code;
1024	u8	rxstale;
1025};
1026
1027static const struct msm_baud_map *
1028msm_find_best_baud(struct uart_port *port, unsigned int baud,
1029		   unsigned long *rate)
1030{
1031	struct msm_port *msm_port = UART_TO_MSM(port);
1032	unsigned int divisor, result;
1033	unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX;
1034	const struct msm_baud_map *entry, *end, *best;
1035	static const struct msm_baud_map table[] = {
1036		{    1, 0xff, 31 },
1037		{    2, 0xee, 16 },
1038		{    3, 0xdd,  8 },
1039		{    4, 0xcc,  6 },
1040		{    6, 0xbb,  6 },
1041		{    8, 0xaa,  6 },
1042		{   12, 0x99,  6 },
1043		{   16, 0x88,  1 },
1044		{   24, 0x77,  1 },
1045		{   32, 0x66,  1 },
1046		{   48, 0x55,  1 },
1047		{   96, 0x44,  1 },
1048		{  192, 0x33,  1 },
1049		{  384, 0x22,  1 },
1050		{  768, 0x11,  1 },
1051		{ 1536, 0x00,  1 },
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1052	};
1053
1054	best = table; /* Default to smallest divider */
1055	target = clk_round_rate(msm_port->clk, 16 * baud);
1056	divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1057
1058	end = table + ARRAY_SIZE(table);
1059	entry = table;
1060	while (entry < end) {
1061		if (entry->divisor <= divisor) {
1062			result = target / entry->divisor / 16;
1063			diff = abs(result - baud);
1064
1065			/* Keep track of best entry */
1066			if (diff < best_diff) {
1067				best_diff = diff;
1068				best = entry;
1069				best_rate = target;
1070			}
1071
1072			if (result == baud)
1073				break;
1074		} else if (entry->divisor > divisor) {
1075			old = target;
1076			target = clk_round_rate(msm_port->clk, old + 1);
1077			/*
1078			 * The rate didn't get any faster so we can't do
1079			 * better at dividing it down
1080			 */
1081			if (target == old)
1082				break;
1083
1084			/* Start the divisor search over at this new rate */
1085			entry = table;
1086			divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1087			continue;
1088		}
1089		entry++;
1090	}
1091
1092	*rate = best_rate;
1093	return best;
1094}
1095
1096static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
1097			     unsigned long *saved_flags)
1098{
1099	unsigned int rxstale, watermark, mask;
1100	struct msm_port *msm_port = UART_TO_MSM(port);
1101	const struct msm_baud_map *entry;
1102	unsigned long flags, rate;
1103
1104	flags = *saved_flags;
1105	spin_unlock_irqrestore(&port->lock, flags);
1106
1107	entry = msm_find_best_baud(port, baud, &rate);
1108	clk_set_rate(msm_port->clk, rate);
1109	baud = rate / 16 / entry->divisor;
1110
1111	spin_lock_irqsave(&port->lock, flags);
1112	*saved_flags = flags;
1113	port->uartclk = rate;
1114
1115	msm_write(port, entry->code, UART_CSR);
1116
1117	/* RX stale watermark */
1118	rxstale = entry->rxstale;
1119	watermark = UART_IPR_STALE_LSB & rxstale;
1120	if (msm_port->is_uartdm) {
1121		mask = UART_DM_IPR_STALE_TIMEOUT_MSB;
1122	} else {
1123		watermark |= UART_IPR_RXSTALE_LAST;
1124		mask = UART_IPR_STALE_TIMEOUT_MSB;
1125	}
1126
1127	watermark |= mask & (rxstale << 2);
1128
1129	msm_write(port, watermark, UART_IPR);
1130
1131	/* set RX watermark */
1132	watermark = (port->fifosize * 3) / 4;
1133	msm_write(port, watermark, UART_RFWR);
1134
1135	/* set TX watermark */
1136	msm_write(port, 10, UART_TFWR);
1137
1138	msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
1139	msm_reset(port);
1140
1141	/* Enable RX and TX */
1142	msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR);
1143
1144	/* turn on RX and CTS interrupts */
1145	msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
1146			UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START;
1147
1148	msm_write(port, msm_port->imr, UART_IMR);
1149
1150	if (msm_port->is_uartdm) {
1151		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
1152		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1153		msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
1154	}
1155
1156	return baud;
1157}
1158
 
1159static void msm_init_clock(struct uart_port *port)
1160{
1161	struct msm_port *msm_port = UART_TO_MSM(port);
1162
1163	clk_prepare_enable(msm_port->clk);
1164	clk_prepare_enable(msm_port->pclk);
1165	msm_serial_set_mnd_regs(port);
1166}
1167
1168static int msm_startup(struct uart_port *port)
1169{
1170	struct msm_port *msm_port = UART_TO_MSM(port);
1171	unsigned int data, rfr_level, mask;
1172	int ret;
1173
1174	snprintf(msm_port->name, sizeof(msm_port->name),
1175		 "msm_serial%d", port->line);
1176
 
 
 
 
 
1177	msm_init_clock(port);
1178
1179	if (likely(port->fifosize > 12))
1180		rfr_level = port->fifosize - 12;
1181	else
1182		rfr_level = port->fifosize;
1183
1184	/* set automatic RFR level */
1185	data = msm_read(port, UART_MR1);
1186
1187	if (msm_port->is_uartdm)
1188		mask = UART_DM_MR1_AUTO_RFR_LEVEL1;
1189	else
1190		mask = UART_MR1_AUTO_RFR_LEVEL1;
1191
1192	data &= ~mask;
1193	data &= ~UART_MR1_AUTO_RFR_LEVEL0;
1194	data |= mask & (rfr_level << 2);
1195	data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
1196	msm_write(port, data, UART_MR1);
1197
1198	if (msm_port->is_uartdm) {
1199		msm_request_tx_dma(msm_port, msm_port->uart.mapbase);
1200		msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
 
 
 
1201	}
1202
1203	ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH,
1204			  msm_port->name, port);
1205	if (unlikely(ret))
1206		goto err_irq;
 
 
1207
1208	return 0;
 
1209
1210err_irq:
1211	if (msm_port->is_uartdm)
1212		msm_release_dma(msm_port);
1213
1214	clk_disable_unprepare(msm_port->pclk);
1215	clk_disable_unprepare(msm_port->clk);
 
1216
1217	return ret;
 
 
 
 
 
 
 
1218}
1219
1220static void msm_shutdown(struct uart_port *port)
1221{
1222	struct msm_port *msm_port = UART_TO_MSM(port);
1223
1224	msm_port->imr = 0;
1225	msm_write(port, 0, UART_IMR); /* disable interrupts */
1226
1227	if (msm_port->is_uartdm)
1228		msm_release_dma(msm_port);
1229
1230	clk_disable_unprepare(msm_port->clk);
1231
1232	free_irq(port->irq, port);
1233}
1234
1235static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
1236			    struct ktermios *old)
1237{
1238	struct msm_port *msm_port = UART_TO_MSM(port);
1239	struct msm_dma *dma = &msm_port->rx_dma;
1240	unsigned long flags;
1241	unsigned int baud, mr;
1242
1243	spin_lock_irqsave(&port->lock, flags);
1244
1245	if (dma->chan) /* Terminate if any */
1246		msm_stop_dma(port, dma);
1247
1248	/* calculate and set baud rate */
1249	baud = uart_get_baud_rate(port, termios, old, 300, 4000000);
1250	baud = msm_set_baud_rate(port, baud, &flags);
1251	if (tty_termios_baud_rate(termios))
1252		tty_termios_encode_baud_rate(termios, baud, baud);
1253
1254	/* calculate parity */
1255	mr = msm_read(port, UART_MR2);
1256	mr &= ~UART_MR2_PARITY_MODE;
1257	if (termios->c_cflag & PARENB) {
1258		if (termios->c_cflag & PARODD)
1259			mr |= UART_MR2_PARITY_MODE_ODD;
1260		else if (termios->c_cflag & CMSPAR)
1261			mr |= UART_MR2_PARITY_MODE_SPACE;
1262		else
1263			mr |= UART_MR2_PARITY_MODE_EVEN;
1264	}
1265
1266	/* calculate bits per char */
1267	mr &= ~UART_MR2_BITS_PER_CHAR;
1268	switch (termios->c_cflag & CSIZE) {
1269	case CS5:
1270		mr |= UART_MR2_BITS_PER_CHAR_5;
1271		break;
1272	case CS6:
1273		mr |= UART_MR2_BITS_PER_CHAR_6;
1274		break;
1275	case CS7:
1276		mr |= UART_MR2_BITS_PER_CHAR_7;
1277		break;
1278	case CS8:
1279	default:
1280		mr |= UART_MR2_BITS_PER_CHAR_8;
1281		break;
1282	}
1283
1284	/* calculate stop bits */
1285	mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
1286	if (termios->c_cflag & CSTOPB)
1287		mr |= UART_MR2_STOP_BIT_LEN_TWO;
1288	else
1289		mr |= UART_MR2_STOP_BIT_LEN_ONE;
1290
1291	/* set parity, bits per char, and stop bit */
1292	msm_write(port, mr, UART_MR2);
1293
1294	/* calculate and set hardware flow control */
1295	mr = msm_read(port, UART_MR1);
1296	mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
1297	if (termios->c_cflag & CRTSCTS) {
1298		mr |= UART_MR1_CTS_CTL;
1299		mr |= UART_MR1_RX_RDY_CTL;
1300	}
1301	msm_write(port, mr, UART_MR1);
1302
1303	/* Configure status bits to ignore based on termio flags. */
1304	port->read_status_mask = 0;
1305	if (termios->c_iflag & INPCK)
1306		port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
1307	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1308		port->read_status_mask |= UART_SR_RX_BREAK;
1309
1310	uart_update_timeout(port, termios->c_cflag, baud);
1311
1312	/* Try to use DMA */
1313	msm_start_rx_dma(msm_port);
1314
1315	spin_unlock_irqrestore(&port->lock, flags);
1316}
1317
1318static const char *msm_type(struct uart_port *port)
1319{
1320	return "MSM";
1321}
1322
1323static void msm_release_port(struct uart_port *port)
1324{
1325	struct platform_device *pdev = to_platform_device(port->dev);
 
1326	struct resource *uart_resource;
 
1327	resource_size_t size;
1328
1329	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1330	if (unlikely(!uart_resource))
1331		return;
1332	size = resource_size(uart_resource);
1333
1334	release_mem_region(port->mapbase, size);
1335	iounmap(port->membase);
1336	port->membase = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1337}
1338
1339static int msm_request_port(struct uart_port *port)
1340{
 
1341	struct platform_device *pdev = to_platform_device(port->dev);
1342	struct resource *uart_resource;
 
1343	resource_size_t size;
1344	int ret;
1345
1346	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1347	if (unlikely(!uart_resource))
1348		return -ENXIO;
1349
1350	size = resource_size(uart_resource);
1351
1352	if (!request_mem_region(port->mapbase, size, "msm_serial"))
1353		return -EBUSY;
1354
1355	port->membase = ioremap(port->mapbase, size);
1356	if (!port->membase) {
1357		ret = -EBUSY;
1358		goto fail_release_port;
1359	}
1360
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1361	return 0;
1362
 
 
 
 
1363fail_release_port:
1364	release_mem_region(port->mapbase, size);
1365	return ret;
1366}
1367
1368static void msm_config_port(struct uart_port *port, int flags)
1369{
 
1370	int ret;
1371
1372	if (flags & UART_CONFIG_TYPE) {
1373		port->type = PORT_MSM;
1374		ret = msm_request_port(port);
1375		if (ret)
1376			return;
1377	}
 
 
 
1378}
1379
1380static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
1381{
1382	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
1383		return -EINVAL;
1384	if (unlikely(port->irq != ser->irq))
1385		return -EINVAL;
1386	return 0;
1387}
1388
1389static void msm_power(struct uart_port *port, unsigned int state,
1390		      unsigned int oldstate)
1391{
1392	struct msm_port *msm_port = UART_TO_MSM(port);
1393
1394	switch (state) {
1395	case 0:
1396		clk_prepare_enable(msm_port->clk);
1397		clk_prepare_enable(msm_port->pclk);
1398		break;
1399	case 3:
1400		clk_disable_unprepare(msm_port->clk);
1401		clk_disable_unprepare(msm_port->pclk);
1402		break;
1403	default:
1404		pr_err("msm_serial: Unknown PM state %d\n", state);
1405	}
1406}
1407
1408#ifdef CONFIG_CONSOLE_POLL
 
 
 
 
 
 
 
 
 
 
 
1409static int msm_poll_get_char_single(struct uart_port *port)
1410{
1411	struct msm_port *msm_port = UART_TO_MSM(port);
1412	unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;
1413
1414	if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))
1415		return NO_POLL_CHAR;
1416
1417	return msm_read(port, rf_reg) & 0xff;
1418}
1419
1420static int msm_poll_get_char_dm(struct uart_port *port)
1421{
1422	int c;
1423	static u32 slop;
1424	static int count;
1425	unsigned char *sp = (unsigned char *)&slop;
1426
1427	/* Check if a previous read had more than one char */
1428	if (count) {
1429		c = sp[sizeof(slop) - count];
1430		count--;
1431	/* Or if FIFO is empty */
1432	} else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {
1433		/*
1434		 * If RX packing buffer has less than a word, force stale to
1435		 * push contents into RX FIFO
1436		 */
1437		count = msm_read(port, UARTDM_RXFS);
1438		count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
1439		if (count) {
1440			msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);
1441			slop = msm_read(port, UARTDM_RF);
1442			c = sp[0];
1443			count--;
1444			msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
1445			msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1446			msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE,
1447				  UART_CR);
1448		} else {
1449			c = NO_POLL_CHAR;
1450		}
1451	/* FIFO has a word */
1452	} else {
1453		slop = msm_read(port, UARTDM_RF);
1454		c = sp[0];
1455		count = sizeof(slop) - 1;
1456	}
1457
1458	return c;
1459}
1460
1461static int msm_poll_get_char(struct uart_port *port)
1462{
1463	u32 imr;
1464	int c;
1465	struct msm_port *msm_port = UART_TO_MSM(port);
1466
1467	/* Disable all interrupts */
1468	imr = msm_read(port, UART_IMR);
1469	msm_write(port, 0, UART_IMR);
1470
1471	if (msm_port->is_uartdm)
1472		c = msm_poll_get_char_dm(port);
1473	else
1474		c = msm_poll_get_char_single(port);
1475
1476	/* Enable interrupts */
1477	msm_write(port, imr, UART_IMR);
1478
1479	return c;
1480}
1481
1482static void msm_poll_put_char(struct uart_port *port, unsigned char c)
1483{
1484	u32 imr;
1485	struct msm_port *msm_port = UART_TO_MSM(port);
1486
1487	/* Disable all interrupts */
1488	imr = msm_read(port, UART_IMR);
1489	msm_write(port, 0, UART_IMR);
1490
1491	if (msm_port->is_uartdm)
1492		msm_reset_dm_count(port, 1);
1493
1494	/* Wait until FIFO is empty */
1495	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
1496		cpu_relax();
1497
1498	/* Write a character */
1499	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
1500
1501	/* Wait until FIFO is empty */
1502	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
1503		cpu_relax();
1504
1505	/* Enable interrupts */
1506	msm_write(port, imr, UART_IMR);
 
 
1507}
1508#endif
1509
1510static struct uart_ops msm_uart_pops = {
1511	.tx_empty = msm_tx_empty,
1512	.set_mctrl = msm_set_mctrl,
1513	.get_mctrl = msm_get_mctrl,
1514	.stop_tx = msm_stop_tx,
1515	.start_tx = msm_start_tx,
1516	.stop_rx = msm_stop_rx,
1517	.enable_ms = msm_enable_ms,
1518	.break_ctl = msm_break_ctl,
1519	.startup = msm_startup,
1520	.shutdown = msm_shutdown,
1521	.set_termios = msm_set_termios,
1522	.type = msm_type,
1523	.release_port = msm_release_port,
1524	.request_port = msm_request_port,
1525	.config_port = msm_config_port,
1526	.verify_port = msm_verify_port,
1527	.pm = msm_power,
1528#ifdef CONFIG_CONSOLE_POLL
 
1529	.poll_get_char	= msm_poll_get_char,
1530	.poll_put_char	= msm_poll_put_char,
1531#endif
1532};
1533
1534static struct msm_port msm_uart_ports[] = {
1535	{
1536		.uart = {
1537			.iotype = UPIO_MEM,
1538			.ops = &msm_uart_pops,
1539			.flags = UPF_BOOT_AUTOCONF,
1540			.fifosize = 64,
1541			.line = 0,
1542		},
1543	},
1544	{
1545		.uart = {
1546			.iotype = UPIO_MEM,
1547			.ops = &msm_uart_pops,
1548			.flags = UPF_BOOT_AUTOCONF,
1549			.fifosize = 64,
1550			.line = 1,
1551		},
1552	},
1553	{
1554		.uart = {
1555			.iotype = UPIO_MEM,
1556			.ops = &msm_uart_pops,
1557			.flags = UPF_BOOT_AUTOCONF,
1558			.fifosize = 64,
1559			.line = 2,
1560		},
1561	},
1562};
1563
1564#define UART_NR	ARRAY_SIZE(msm_uart_ports)
1565
1566static inline struct uart_port *msm_get_port_from_line(unsigned int line)
1567{
1568	return &msm_uart_ports[line].uart;
1569}
1570
1571#ifdef CONFIG_SERIAL_MSM_CONSOLE
1572static void __msm_console_write(struct uart_port *port, const char *s,
1573				unsigned int count, bool is_uartdm)
1574{
1575	int i;
 
 
1576	int num_newlines = 0;
1577	bool replaced = false;
1578	void __iomem *tf;
1579
1580	if (is_uartdm)
1581		tf = port->membase + UARTDM_TF;
1582	else
1583		tf = port->membase + UART_TF;
1584
1585	/* Account for newlines that will get a carriage return added */
1586	for (i = 0; i < count; i++)
1587		if (s[i] == '\n')
1588			num_newlines++;
1589	count += num_newlines;
1590
1591	spin_lock(&port->lock);
1592	if (is_uartdm)
1593		msm_reset_dm_count(port, count);
1594
1595	i = 0;
1596	while (i < count) {
1597		int j;
1598		unsigned int num_chars;
1599		char buf[4] = { 0 };
 
1600
1601		if (is_uartdm)
1602			num_chars = min(count - i, (unsigned int)sizeof(buf));
1603		else
1604			num_chars = 1;
1605
1606		for (j = 0; j < num_chars; j++) {
1607			char c = *s;
1608
1609			if (c == '\n' && !replaced) {
1610				buf[j] = '\r';
1611				j++;
1612				replaced = true;
1613			}
1614			if (j < num_chars) {
1615				buf[j] = c;
1616				s++;
1617				replaced = false;
1618			}
1619		}
1620
1621		while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
1622			cpu_relax();
1623
1624		iowrite32_rep(tf, buf, 1);
1625		i += num_chars;
1626	}
1627	spin_unlock(&port->lock);
1628}
1629
1630static void msm_console_write(struct console *co, const char *s,
1631			      unsigned int count)
1632{
1633	struct uart_port *port;
1634	struct msm_port *msm_port;
1635
1636	BUG_ON(co->index < 0 || co->index >= UART_NR);
1637
1638	port = msm_get_port_from_line(co->index);
1639	msm_port = UART_TO_MSM(port);
1640
1641	__msm_console_write(port, s, count, msm_port->is_uartdm);
1642}
1643
1644static int msm_console_setup(struct console *co, char *options)
1645{
1646	struct uart_port *port;
1647	int baud = 115200;
1648	int bits = 8;
1649	int parity = 'n';
1650	int flow = 'n';
1651
1652	if (unlikely(co->index >= UART_NR || co->index < 0))
1653		return -ENXIO;
1654
1655	port = msm_get_port_from_line(co->index);
 
1656
1657	if (unlikely(!port->membase))
1658		return -ENXIO;
1659
1660	msm_init_clock(port);
1661
1662	if (options)
1663		uart_parse_options(options, &baud, &parity, &bits, &flow);
1664
1665	pr_info("msm_serial: console setup on port #%d\n", port->line);
 
 
 
 
 
 
 
 
1666
1667	return uart_set_options(port, co, baud, parity, bits, flow);
1668}
1669
1670static void
1671msm_serial_early_write(struct console *con, const char *s, unsigned n)
1672{
1673	struct earlycon_device *dev = con->data;
1674
1675	__msm_console_write(&dev->port, s, n, false);
1676}
1677
1678static int __init
1679msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
1680{
1681	if (!device->port.membase)
1682		return -ENODEV;
1683
1684	device->con->write = msm_serial_early_write;
1685	return 0;
1686}
1687OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
1688		    msm_serial_early_console_setup);
1689
1690static void
1691msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
1692{
1693	struct earlycon_device *dev = con->data;
1694
1695	__msm_console_write(&dev->port, s, n, true);
1696}
 
 
1697
1698static int __init
1699msm_serial_early_console_setup_dm(struct earlycon_device *device,
1700				  const char *opt)
1701{
1702	if (!device->port.membase)
1703		return -ENODEV;
1704
1705	device->con->write = msm_serial_early_write_dm;
1706	return 0;
1707}
1708OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
1709		    msm_serial_early_console_setup_dm);
1710
1711static struct uart_driver msm_uart_driver;
1712
1713static struct console msm_console = {
1714	.name = "ttyMSM",
1715	.write = msm_console_write,
1716	.device = uart_console_device,
1717	.setup = msm_console_setup,
1718	.flags = CON_PRINTBUFFER,
1719	.index = -1,
1720	.data = &msm_uart_driver,
1721};
1722
1723#define MSM_CONSOLE	(&msm_console)
1724
1725#else
1726#define MSM_CONSOLE	NULL
1727#endif
1728
1729static struct uart_driver msm_uart_driver = {
1730	.owner = THIS_MODULE,
1731	.driver_name = "msm_serial",
1732	.dev_name = "ttyMSM",
1733	.nr = UART_NR,
1734	.cons = MSM_CONSOLE,
1735};
1736
1737static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
1738
1739static const struct of_device_id msm_uartdm_table[] = {
1740	{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
1741	{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
1742	{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
1743	{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
1744	{ }
1745};
1746
1747static int msm_serial_probe(struct platform_device *pdev)
1748{
1749	struct msm_port *msm_port;
1750	struct resource *resource;
1751	struct uart_port *port;
1752	const struct of_device_id *id;
1753	int irq, line;
1754
1755	if (pdev->dev.of_node)
1756		line = of_alias_get_id(pdev->dev.of_node, "serial");
1757	else
1758		line = pdev->id;
1759
1760	if (line < 0)
1761		line = atomic_inc_return(&msm_uart_next_id) - 1;
1762
1763	if (unlikely(line < 0 || line >= UART_NR))
1764		return -ENXIO;
1765
1766	dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
1767
1768	port = msm_get_port_from_line(line);
1769	port->dev = &pdev->dev;
1770	msm_port = UART_TO_MSM(port);
1771
1772	id = of_match_device(msm_uartdm_table, &pdev->dev);
1773	if (id)
1774		msm_port->is_uartdm = (unsigned long)id->data;
1775	else
1776		msm_port->is_uartdm = 0;
1777
1778	msm_port->clk = devm_clk_get(&pdev->dev, "core");
1779	if (IS_ERR(msm_port->clk))
1780		return PTR_ERR(msm_port->clk);
1781
1782	if (msm_port->is_uartdm) {
1783		msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
1784		if (IS_ERR(msm_port->pclk))
1785			return PTR_ERR(msm_port->pclk);
 
 
1786	}
1787
1788	port->uartclk = clk_get_rate(msm_port->clk);
1789	dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
 
1790
1791	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1792	if (unlikely(!resource))
1793		return -ENXIO;
1794	port->mapbase = resource->start;
1795
1796	irq = platform_get_irq(pdev, 0);
1797	if (unlikely(irq < 0))
1798		return -ENXIO;
1799	port->irq = irq;
1800
1801	platform_set_drvdata(pdev, port);
1802
1803	return uart_add_one_port(&msm_uart_driver, port);
1804}
1805
1806static int msm_serial_remove(struct platform_device *pdev)
1807{
1808	struct uart_port *port = platform_get_drvdata(pdev);
1809
1810	uart_remove_one_port(&msm_uart_driver, port);
1811
1812	return 0;
1813}
1814
1815static const struct of_device_id msm_match_table[] = {
1816	{ .compatible = "qcom,msm-uart" },
1817	{ .compatible = "qcom,msm-uartdm" },
1818	{}
1819};
1820MODULE_DEVICE_TABLE(of, msm_match_table);
1821
1822static int __maybe_unused msm_serial_suspend(struct device *dev)
1823{
1824	struct msm_port *port = dev_get_drvdata(dev);
1825
1826	uart_suspend_port(&msm_uart_driver, &port->uart);
1827
1828	return 0;
1829}
1830
1831static int __maybe_unused msm_serial_resume(struct device *dev)
1832{
1833	struct msm_port *port = dev_get_drvdata(dev);
1834
1835	uart_resume_port(&msm_uart_driver, &port->uart);
1836
1837	return 0;
1838}
1839
1840static const struct dev_pm_ops msm_serial_dev_pm_ops = {
1841	SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
1842};
1843
1844static struct platform_driver msm_platform_driver = {
1845	.remove = msm_serial_remove,
1846	.probe = msm_serial_probe,
1847	.driver = {
1848		.name = "msm_serial",
1849		.pm = &msm_serial_dev_pm_ops,
1850		.of_match_table = msm_match_table,
1851	},
1852};
1853
1854static int __init msm_serial_init(void)
1855{
1856	int ret;
1857
1858	ret = uart_register_driver(&msm_uart_driver);
1859	if (unlikely(ret))
1860		return ret;
1861
1862	ret = platform_driver_register(&msm_platform_driver);
1863	if (unlikely(ret))
1864		uart_unregister_driver(&msm_uart_driver);
1865
1866	pr_info("msm_serial: driver initialized\n");
1867
1868	return ret;
1869}
1870
1871static void __exit msm_serial_exit(void)
1872{
 
 
 
1873	platform_driver_unregister(&msm_platform_driver);
1874	uart_unregister_driver(&msm_uart_driver);
1875}
1876
1877module_init(msm_serial_init);
1878module_exit(msm_serial_exit);
1879
1880MODULE_AUTHOR("Robert Love <rlove@google.com>");
1881MODULE_DESCRIPTION("Driver for msm7x serial device");
1882MODULE_LICENSE("GPL");
v3.15
 
   1/*
   2 * Driver for msm7k serial device and console
   3 *
   4 * Copyright (C) 2007 Google, Inc.
   5 * Author: Robert Love <rlove@google.com>
   6 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
   7 *
   8 * This software is licensed under the terms of the GNU General Public
   9 * License version 2, as published by the Free Software Foundation, and
  10 * may be copied, distributed, and modified under those terms.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  19# define SUPPORT_SYSRQ
  20#endif
  21
 
  22#include <linux/atomic.h>
  23#include <linux/hrtimer.h>
 
  24#include <linux/module.h>
  25#include <linux/io.h>
  26#include <linux/ioport.h>
  27#include <linux/irq.h>
  28#include <linux/init.h>
  29#include <linux/console.h>
  30#include <linux/tty.h>
  31#include <linux/tty_flip.h>
  32#include <linux/serial_core.h>
  33#include <linux/serial.h>
  34#include <linux/clk.h>
  35#include <linux/platform_device.h>
  36#include <linux/delay.h>
  37#include <linux/of.h>
  38#include <linux/of_device.h>
 
  39
  40#include "msm_serial.h"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  41
  42enum {
  43	UARTDM_1P1 = 1,
  44	UARTDM_1P2,
  45	UARTDM_1P3,
  46	UARTDM_1P4,
  47};
  48
 
 
 
 
 
 
 
 
 
 
 
  49struct msm_port {
  50	struct uart_port	uart;
  51	char			name[16];
  52	struct clk		*clk;
  53	struct clk		*pclk;
  54	unsigned int		imr;
  55	void __iomem		*gsbi_base;
  56	int			is_uartdm;
  57	unsigned int		old_snap_state;
 
 
 
  58};
  59
  60static inline void wait_for_xmitr(struct uart_port *port)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  61{
 
 
  62	while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) {
  63		if (msm_read(port, UART_ISR) & UART_ISR_TX_READY)
  64			break;
  65		udelay(1);
 
 
  66	}
  67	msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR);
  68}
  69
  70static void msm_stop_tx(struct uart_port *port)
  71{
  72	struct msm_port *msm_port = UART_TO_MSM(port);
  73
  74	msm_port->imr &= ~UART_IMR_TXLEV;
  75	msm_write(port, msm_port->imr, UART_IMR);
  76}
  77
  78static void msm_start_tx(struct uart_port *port)
  79{
  80	struct msm_port *msm_port = UART_TO_MSM(port);
 
 
 
 
 
 
 
 
 
  81
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  82	msm_port->imr |= UART_IMR_TXLEV;
  83	msm_write(port, msm_port->imr, UART_IMR);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  84}
  85
  86static void msm_stop_rx(struct uart_port *port)
  87{
  88	struct msm_port *msm_port = UART_TO_MSM(port);
 
  89
  90	msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
  91	msm_write(port, msm_port->imr, UART_IMR);
 
 
 
  92}
  93
  94static void msm_enable_ms(struct uart_port *port)
  95{
  96	struct msm_port *msm_port = UART_TO_MSM(port);
  97
  98	msm_port->imr |= UART_IMR_DELTA_CTS;
  99	msm_write(port, msm_port->imr, UART_IMR);
 100}
 101
 102static void handle_rx_dm(struct uart_port *port, unsigned int misr)
 103{
 104	struct tty_port *tport = &port->state->port;
 105	unsigned int sr;
 106	int count = 0;
 107	struct msm_port *msm_port = UART_TO_MSM(port);
 108
 109	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
 110		port->icount.overrun++;
 111		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 112		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 113	}
 114
 115	if (misr & UART_IMR_RXSTALE) {
 116		count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
 117			msm_port->old_snap_state;
 118		msm_port->old_snap_state = 0;
 119	} else {
 120		count = 4 * (msm_read(port, UART_RFWR));
 121		msm_port->old_snap_state += count;
 122	}
 123
 124	/* TODO: Precise error reporting */
 125
 126	port->icount.rx += count;
 127
 128	while (count > 0) {
 129		unsigned int c;
 
 130
 131		sr = msm_read(port, UART_SR);
 132		if ((sr & UART_SR_RX_READY) == 0) {
 133			msm_port->old_snap_state -= count;
 134			break;
 135		}
 136		c = msm_read(port, UARTDM_RF);
 137		if (sr & UART_SR_RX_BREAK) {
 138			port->icount.brk++;
 139			if (uart_handle_break(port))
 140				continue;
 141		} else if (sr & UART_SR_PAR_FRAME_ERR)
 142			port->icount.frame++;
 143
 144		/* TODO: handle sysrq */
 145		tty_insert_flip_string(tport, (char *)&c,
 146				       (count > 4) ? 4 : count);
 147		count -= 4;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 148	}
 149
 150	spin_unlock(&port->lock);
 151	tty_flip_buffer_push(tport);
 152	spin_lock(&port->lock);
 153
 154	if (misr & (UART_IMR_RXSTALE))
 155		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
 156	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
 157	msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
 
 
 
 158}
 159
 160static void handle_rx(struct uart_port *port)
 161{
 162	struct tty_port *tport = &port->state->port;
 163	unsigned int sr;
 164
 165	/*
 166	 * Handle overrun. My understanding of the hardware is that overrun
 167	 * is not tied to the RX buffer, so we handle the case out of band.
 168	 */
 169	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
 170		port->icount.overrun++;
 171		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 172		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 173	}
 174
 175	/* and now the main RX loop */
 176	while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
 177		unsigned int c;
 178		char flag = TTY_NORMAL;
 
 179
 180		c = msm_read(port, UART_RF);
 181
 182		if (sr & UART_SR_RX_BREAK) {
 183			port->icount.brk++;
 184			if (uart_handle_break(port))
 185				continue;
 186		} else if (sr & UART_SR_PAR_FRAME_ERR) {
 187			port->icount.frame++;
 188		} else {
 189			port->icount.rx++;
 190		}
 191
 192		/* Mask conditions we're ignorning. */
 193		sr &= port->read_status_mask;
 194
 195		if (sr & UART_SR_RX_BREAK) {
 196			flag = TTY_BREAK;
 197		} else if (sr & UART_SR_PAR_FRAME_ERR) {
 198			flag = TTY_FRAME;
 199		}
 200
 201		if (!uart_handle_sysrq_char(port, c))
 
 
 
 202			tty_insert_flip_char(tport, c, flag);
 203	}
 204
 205	spin_unlock(&port->lock);
 206	tty_flip_buffer_push(tport);
 207	spin_lock(&port->lock);
 208}
 209
 210static void reset_dm_count(struct uart_port *port, int count)
 211{
 212	wait_for_xmitr(port);
 213	msm_write(port, count, UARTDM_NCF_TX);
 214	msm_read(port, UARTDM_NCF_TX);
 215}
 216
 217static void handle_tx(struct uart_port *port)
 218{
 219	struct circ_buf *xmit = &port->state->xmit;
 220	struct msm_port *msm_port = UART_TO_MSM(port);
 221	unsigned int tx_count, num_chars;
 222	unsigned int tf_pointer = 0;
 
 223
 224	tx_count = uart_circ_chars_pending(xmit);
 225	tx_count = min3(tx_count, (unsigned int)UART_XMIT_SIZE - xmit->tail,
 226			port->fifosize);
 
 227
 228	if (port->x_char) {
 229		if (msm_port->is_uartdm)
 230			reset_dm_count(port, tx_count + 1);
 231
 232		msm_write(port, port->x_char,
 233			  msm_port->is_uartdm ? UARTDM_TF : UART_TF);
 234		port->icount.tx++;
 235		port->x_char = 0;
 236	} else if (tx_count && msm_port->is_uartdm) {
 237		reset_dm_count(port, tx_count);
 238	}
 239
 240	while (tf_pointer < tx_count) {
 241		int i;
 242		char buf[4] = { 0 };
 243		unsigned int *bf = (unsigned int *)&buf;
 244
 245		if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 246			break;
 247
 248		if (msm_port->is_uartdm)
 249			num_chars = min(tx_count - tf_pointer,
 250					(unsigned int)sizeof(buf));
 251		else
 252			num_chars = 1;
 253
 254		for (i = 0; i < num_chars; i++) {
 255			buf[i] = xmit->buf[xmit->tail + i];
 256			port->icount.tx++;
 257		}
 258
 259		msm_write(port, *bf, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
 260		xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
 261		tf_pointer += num_chars;
 262	}
 263
 264	/* disable tx interrupts if nothing more to send */
 265	if (uart_circ_empty(xmit))
 266		msm_stop_tx(port);
 267
 268	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 269		uart_write_wakeup(port);
 270}
 271
 272static void handle_delta_cts(struct uart_port *port)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 273{
 274	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
 275	port->icount.cts++;
 276	wake_up_interruptible(&port->state->port.delta_msr_wait);
 277}
 278
 279static irqreturn_t msm_irq(int irq, void *dev_id)
 280{
 281	struct uart_port *port = dev_id;
 282	struct msm_port *msm_port = UART_TO_MSM(port);
 
 
 283	unsigned int misr;
 
 284
 285	spin_lock(&port->lock);
 286	misr = msm_read(port, UART_MISR);
 287	msm_write(port, 0, UART_IMR); /* disable interrupt */
 288
 
 
 
 
 
 289	if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) {
 290		if (msm_port->is_uartdm)
 291			handle_rx_dm(port, misr);
 292		else
 293			handle_rx(port);
 
 
 
 
 
 
 
 
 
 
 
 294	}
 295	if (misr & UART_IMR_TXLEV)
 296		handle_tx(port);
 297	if (misr & UART_IMR_DELTA_CTS)
 298		handle_delta_cts(port);
 299
 300	msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
 301	spin_unlock(&port->lock);
 302
 303	return IRQ_HANDLED;
 304}
 305
 306static unsigned int msm_tx_empty(struct uart_port *port)
 307{
 308	return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
 309}
 310
 311static unsigned int msm_get_mctrl(struct uart_port *port)
 312{
 313	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
 314}
 315
 316
 317static void msm_reset(struct uart_port *port)
 318{
 319	struct msm_port *msm_port = UART_TO_MSM(port);
 320
 321	/* reset everything */
 322	msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
 323	msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
 324	msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
 325	msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
 326	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
 327	msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
 328
 329	/* Disable DM modes */
 330	if (msm_port->is_uartdm)
 331		msm_write(port, 0, UARTDM_DMEN);
 332}
 333
 334static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
 335{
 336	unsigned int mr;
 
 337	mr = msm_read(port, UART_MR1);
 338
 339	if (!(mctrl & TIOCM_RTS)) {
 340		mr &= ~UART_MR1_RX_RDY_CTL;
 341		msm_write(port, mr, UART_MR1);
 342		msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
 343	} else {
 344		mr |= UART_MR1_RX_RDY_CTL;
 345		msm_write(port, mr, UART_MR1);
 346	}
 347}
 348
 349static void msm_break_ctl(struct uart_port *port, int break_ctl)
 350{
 351	if (break_ctl)
 352		msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
 353	else
 354		msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
 355}
 356
 357struct msm_baud_map {
 358	u16	divisor;
 359	u8	code;
 360	u8	rxstale;
 361};
 362
 363static const struct msm_baud_map *
 364msm_find_best_baud(struct uart_port *port, unsigned int baud)
 
 365{
 366	unsigned int i, divisor;
 367	const struct msm_baud_map *entry;
 
 
 368	static const struct msm_baud_map table[] = {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 369		{ 1536, 0x00,  1 },
 370		{  768, 0x11,  1 },
 371		{  384, 0x22,  1 },
 372		{  192, 0x33,  1 },
 373		{   96, 0x44,  1 },
 374		{   48, 0x55,  1 },
 375		{   32, 0x66,  1 },
 376		{   24, 0x77,  1 },
 377		{   16, 0x88,  1 },
 378		{   12, 0x99,  6 },
 379		{    8, 0xaa,  6 },
 380		{    6, 0xbb,  6 },
 381		{    4, 0xcc,  6 },
 382		{    3, 0xdd,  8 },
 383		{    2, 0xee, 16 },
 384		{    1, 0xff, 31 },
 385	};
 386
 387	divisor = uart_get_divisor(port, baud);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 388
 389	for (i = 0, entry = table; i < ARRAY_SIZE(table); i++, entry++)
 390		if (entry->divisor <= divisor)
 391			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 392
 393	return entry; /* Default to smallest divider */
 
 394}
 395
 396static int msm_set_baud_rate(struct uart_port *port, unsigned int baud)
 
 397{
 398	unsigned int rxstale, watermark;
 399	struct msm_port *msm_port = UART_TO_MSM(port);
 400	const struct msm_baud_map *entry;
 
 
 
 
 401
 402	entry = msm_find_best_baud(port, baud);
 
 
 403
 404	if (msm_port->is_uartdm)
 405		msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
 
 406
 407	msm_write(port, entry->code, UART_CSR);
 408
 409	/* RX stale watermark */
 410	rxstale = entry->rxstale;
 411	watermark = UART_IPR_STALE_LSB & rxstale;
 412	watermark |= UART_IPR_RXSTALE_LAST;
 413	watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2);
 
 
 
 
 
 
 
 414	msm_write(port, watermark, UART_IPR);
 415
 416	/* set RX watermark */
 417	watermark = (port->fifosize * 3) / 4;
 418	msm_write(port, watermark, UART_RFWR);
 419
 420	/* set TX watermark */
 421	msm_write(port, 10, UART_TFWR);
 422
 
 
 
 
 
 
 
 
 
 
 
 
 423	if (msm_port->is_uartdm) {
 424		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
 425		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
 426		msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
 427	}
 428
 429	return baud;
 430}
 431
 432
 433static void msm_init_clock(struct uart_port *port)
 434{
 435	struct msm_port *msm_port = UART_TO_MSM(port);
 436
 437	clk_prepare_enable(msm_port->clk);
 438	clk_prepare_enable(msm_port->pclk);
 439	msm_serial_set_mnd_regs(port);
 440}
 441
 442static int msm_startup(struct uart_port *port)
 443{
 444	struct msm_port *msm_port = UART_TO_MSM(port);
 445	unsigned int data, rfr_level;
 446	int ret;
 447
 448	snprintf(msm_port->name, sizeof(msm_port->name),
 449		 "msm_serial%d", port->line);
 450
 451	ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH,
 452			  msm_port->name, port);
 453	if (unlikely(ret))
 454		return ret;
 455
 456	msm_init_clock(port);
 457
 458	if (likely(port->fifosize > 12))
 459		rfr_level = port->fifosize - 12;
 460	else
 461		rfr_level = port->fifosize;
 462
 463	/* set automatic RFR level */
 464	data = msm_read(port, UART_MR1);
 465	data &= ~UART_MR1_AUTO_RFR_LEVEL1;
 
 
 
 
 
 
 466	data &= ~UART_MR1_AUTO_RFR_LEVEL0;
 467	data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2);
 468	data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
 469	msm_write(port, data, UART_MR1);
 470
 471	/* make sure that RXSTALE count is non-zero */
 472	data = msm_read(port, UART_IPR);
 473	if (unlikely(!data)) {
 474		data |= UART_IPR_RXSTALE_LAST;
 475		data |= UART_IPR_STALE_LSB;
 476		msm_write(port, data, UART_IPR);
 477	}
 478
 479	data = 0;
 480	if (!port->cons || (port->cons && !(port->cons->flags & CON_ENABLED))) {
 481		msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
 482		msm_reset(port);
 483		data = UART_CR_TX_ENABLE;
 484	}
 485
 486	data |= UART_CR_RX_ENABLE;
 487	msm_write(port, data, UART_CR);	/* enable TX & RX */
 488
 489	/* Make sure IPR is not 0 to start with*/
 490	if (msm_port->is_uartdm)
 491		msm_write(port, UART_IPR_STALE_LSB, UART_IPR);
 492
 493	/* turn on RX and CTS interrupts */
 494	msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
 495			UART_IMR_CURRENT_CTS;
 496
 497	if (msm_port->is_uartdm) {
 498		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
 499		msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
 500		msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
 501	}
 502
 503	msm_write(port, msm_port->imr, UART_IMR);
 504	return 0;
 505}
 506
 507static void msm_shutdown(struct uart_port *port)
 508{
 509	struct msm_port *msm_port = UART_TO_MSM(port);
 510
 511	msm_port->imr = 0;
 512	msm_write(port, 0, UART_IMR); /* disable interrupts */
 513
 
 
 
 514	clk_disable_unprepare(msm_port->clk);
 515
 516	free_irq(port->irq, port);
 517}
 518
 519static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
 520			    struct ktermios *old)
 521{
 
 
 522	unsigned long flags;
 523	unsigned int baud, mr;
 524
 525	spin_lock_irqsave(&port->lock, flags);
 526
 
 
 
 527	/* calculate and set baud rate */
 528	baud = uart_get_baud_rate(port, termios, old, 300, 115200);
 529	baud = msm_set_baud_rate(port, baud);
 530	if (tty_termios_baud_rate(termios))
 531		tty_termios_encode_baud_rate(termios, baud, baud);
 532
 533	/* calculate parity */
 534	mr = msm_read(port, UART_MR2);
 535	mr &= ~UART_MR2_PARITY_MODE;
 536	if (termios->c_cflag & PARENB) {
 537		if (termios->c_cflag & PARODD)
 538			mr |= UART_MR2_PARITY_MODE_ODD;
 539		else if (termios->c_cflag & CMSPAR)
 540			mr |= UART_MR2_PARITY_MODE_SPACE;
 541		else
 542			mr |= UART_MR2_PARITY_MODE_EVEN;
 543	}
 544
 545	/* calculate bits per char */
 546	mr &= ~UART_MR2_BITS_PER_CHAR;
 547	switch (termios->c_cflag & CSIZE) {
 548	case CS5:
 549		mr |= UART_MR2_BITS_PER_CHAR_5;
 550		break;
 551	case CS6:
 552		mr |= UART_MR2_BITS_PER_CHAR_6;
 553		break;
 554	case CS7:
 555		mr |= UART_MR2_BITS_PER_CHAR_7;
 556		break;
 557	case CS8:
 558	default:
 559		mr |= UART_MR2_BITS_PER_CHAR_8;
 560		break;
 561	}
 562
 563	/* calculate stop bits */
 564	mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
 565	if (termios->c_cflag & CSTOPB)
 566		mr |= UART_MR2_STOP_BIT_LEN_TWO;
 567	else
 568		mr |= UART_MR2_STOP_BIT_LEN_ONE;
 569
 570	/* set parity, bits per char, and stop bit */
 571	msm_write(port, mr, UART_MR2);
 572
 573	/* calculate and set hardware flow control */
 574	mr = msm_read(port, UART_MR1);
 575	mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
 576	if (termios->c_cflag & CRTSCTS) {
 577		mr |= UART_MR1_CTS_CTL;
 578		mr |= UART_MR1_RX_RDY_CTL;
 579	}
 580	msm_write(port, mr, UART_MR1);
 581
 582	/* Configure status bits to ignore based on termio flags. */
 583	port->read_status_mask = 0;
 584	if (termios->c_iflag & INPCK)
 585		port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
 586	if (termios->c_iflag & (BRKINT | PARMRK))
 587		port->read_status_mask |= UART_SR_RX_BREAK;
 588
 589	uart_update_timeout(port, termios->c_cflag, baud);
 590
 
 
 
 591	spin_unlock_irqrestore(&port->lock, flags);
 592}
 593
 594static const char *msm_type(struct uart_port *port)
 595{
 596	return "MSM";
 597}
 598
 599static void msm_release_port(struct uart_port *port)
 600{
 601	struct platform_device *pdev = to_platform_device(port->dev);
 602	struct msm_port *msm_port = UART_TO_MSM(port);
 603	struct resource *uart_resource;
 604	struct resource *gsbi_resource;
 605	resource_size_t size;
 606
 607	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 608	if (unlikely(!uart_resource))
 609		return;
 610	size = resource_size(uart_resource);
 611
 612	release_mem_region(port->mapbase, size);
 613	iounmap(port->membase);
 614	port->membase = NULL;
 615
 616	if (msm_port->gsbi_base) {
 617		writel_relaxed(GSBI_PROTOCOL_IDLE,
 618				msm_port->gsbi_base + GSBI_CONTROL);
 619
 620		gsbi_resource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 621		if (unlikely(!gsbi_resource))
 622			return;
 623
 624		size = resource_size(gsbi_resource);
 625		release_mem_region(gsbi_resource->start, size);
 626		iounmap(msm_port->gsbi_base);
 627		msm_port->gsbi_base = NULL;
 628	}
 629}
 630
 631static int msm_request_port(struct uart_port *port)
 632{
 633	struct msm_port *msm_port = UART_TO_MSM(port);
 634	struct platform_device *pdev = to_platform_device(port->dev);
 635	struct resource *uart_resource;
 636	struct resource *gsbi_resource;
 637	resource_size_t size;
 638	int ret;
 639
 640	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 641	if (unlikely(!uart_resource))
 642		return -ENXIO;
 643
 644	size = resource_size(uart_resource);
 645
 646	if (!request_mem_region(port->mapbase, size, "msm_serial"))
 647		return -EBUSY;
 648
 649	port->membase = ioremap(port->mapbase, size);
 650	if (!port->membase) {
 651		ret = -EBUSY;
 652		goto fail_release_port;
 653	}
 654
 655	gsbi_resource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 656	/* Is this a GSBI-based port? */
 657	if (gsbi_resource) {
 658		size = resource_size(gsbi_resource);
 659
 660		if (!request_mem_region(gsbi_resource->start, size,
 661						 "msm_serial")) {
 662			ret = -EBUSY;
 663			goto fail_release_port_membase;
 664		}
 665
 666		msm_port->gsbi_base = ioremap(gsbi_resource->start, size);
 667		if (!msm_port->gsbi_base) {
 668			ret = -EBUSY;
 669			goto fail_release_gsbi;
 670		}
 671	}
 672
 673	return 0;
 674
 675fail_release_gsbi:
 676	release_mem_region(gsbi_resource->start, size);
 677fail_release_port_membase:
 678	iounmap(port->membase);
 679fail_release_port:
 680	release_mem_region(port->mapbase, size);
 681	return ret;
 682}
 683
 684static void msm_config_port(struct uart_port *port, int flags)
 685{
 686	struct msm_port *msm_port = UART_TO_MSM(port);
 687	int ret;
 
 688	if (flags & UART_CONFIG_TYPE) {
 689		port->type = PORT_MSM;
 690		ret = msm_request_port(port);
 691		if (ret)
 692			return;
 693	}
 694	if (msm_port->gsbi_base)
 695		writel_relaxed(GSBI_PROTOCOL_UART,
 696				msm_port->gsbi_base + GSBI_CONTROL);
 697}
 698
 699static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
 700{
 701	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
 702		return -EINVAL;
 703	if (unlikely(port->irq != ser->irq))
 704		return -EINVAL;
 705	return 0;
 706}
 707
 708static void msm_power(struct uart_port *port, unsigned int state,
 709		      unsigned int oldstate)
 710{
 711	struct msm_port *msm_port = UART_TO_MSM(port);
 712
 713	switch (state) {
 714	case 0:
 715		clk_prepare_enable(msm_port->clk);
 716		clk_prepare_enable(msm_port->pclk);
 717		break;
 718	case 3:
 719		clk_disable_unprepare(msm_port->clk);
 720		clk_disable_unprepare(msm_port->pclk);
 721		break;
 722	default:
 723		printk(KERN_ERR "msm_serial: Unknown PM state %d\n", state);
 724	}
 725}
 726
 727#ifdef CONFIG_CONSOLE_POLL
 728static int msm_poll_init(struct uart_port *port)
 729{
 730	struct msm_port *msm_port = UART_TO_MSM(port);
 731
 732	/* Enable single character mode on RX FIFO */
 733	if (msm_port->is_uartdm >= UARTDM_1P4)
 734		msm_write(port, UARTDM_DMEN_RX_SC_ENABLE, UARTDM_DMEN);
 735
 736	return 0;
 737}
 738
 739static int msm_poll_get_char_single(struct uart_port *port)
 740{
 741	struct msm_port *msm_port = UART_TO_MSM(port);
 742	unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;
 743
 744	if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))
 745		return NO_POLL_CHAR;
 746	else
 747		return msm_read(port, rf_reg) & 0xff;
 748}
 749
 750static int msm_poll_get_char_dm_1p3(struct uart_port *port)
 751{
 752	int c;
 753	static u32 slop;
 754	static int count;
 755	unsigned char *sp = (unsigned char *)&slop;
 756
 757	/* Check if a previous read had more than one char */
 758	if (count) {
 759		c = sp[sizeof(slop) - count];
 760		count--;
 761	/* Or if FIFO is empty */
 762	} else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {
 763		/*
 764		 * If RX packing buffer has less than a word, force stale to
 765		 * push contents into RX FIFO
 766		 */
 767		count = msm_read(port, UARTDM_RXFS);
 768		count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
 769		if (count) {
 770			msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);
 771			slop = msm_read(port, UARTDM_RF);
 772			c = sp[0];
 773			count--;
 
 
 
 
 774		} else {
 775			c = NO_POLL_CHAR;
 776		}
 777	/* FIFO has a word */
 778	} else {
 779		slop = msm_read(port, UARTDM_RF);
 780		c = sp[0];
 781		count = sizeof(slop) - 1;
 782	}
 783
 784	return c;
 785}
 786
 787static int msm_poll_get_char(struct uart_port *port)
 788{
 789	u32 imr;
 790	int c;
 791	struct msm_port *msm_port = UART_TO_MSM(port);
 792
 793	/* Disable all interrupts */
 794	imr = msm_read(port, UART_IMR);
 795	msm_write(port, 0, UART_IMR);
 796
 797	if (msm_port->is_uartdm == UARTDM_1P3)
 798		c = msm_poll_get_char_dm_1p3(port);
 799	else
 800		c = msm_poll_get_char_single(port);
 801
 802	/* Enable interrupts */
 803	msm_write(port, imr, UART_IMR);
 804
 805	return c;
 806}
 807
 808static void msm_poll_put_char(struct uart_port *port, unsigned char c)
 809{
 810	u32 imr;
 811	struct msm_port *msm_port = UART_TO_MSM(port);
 812
 813	/* Disable all interrupts */
 814	imr = msm_read(port, UART_IMR);
 815	msm_write(port, 0, UART_IMR);
 816
 817	if (msm_port->is_uartdm)
 818		reset_dm_count(port, 1);
 819
 820	/* Wait until FIFO is empty */
 821	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 822		cpu_relax();
 823
 824	/* Write a character */
 825	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
 826
 827	/* Wait until FIFO is empty */
 828	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 829		cpu_relax();
 830
 831	/* Enable interrupts */
 832	msm_write(port, imr, UART_IMR);
 833
 834	return;
 835}
 836#endif
 837
 838static struct uart_ops msm_uart_pops = {
 839	.tx_empty = msm_tx_empty,
 840	.set_mctrl = msm_set_mctrl,
 841	.get_mctrl = msm_get_mctrl,
 842	.stop_tx = msm_stop_tx,
 843	.start_tx = msm_start_tx,
 844	.stop_rx = msm_stop_rx,
 845	.enable_ms = msm_enable_ms,
 846	.break_ctl = msm_break_ctl,
 847	.startup = msm_startup,
 848	.shutdown = msm_shutdown,
 849	.set_termios = msm_set_termios,
 850	.type = msm_type,
 851	.release_port = msm_release_port,
 852	.request_port = msm_request_port,
 853	.config_port = msm_config_port,
 854	.verify_port = msm_verify_port,
 855	.pm = msm_power,
 856#ifdef CONFIG_CONSOLE_POLL
 857	.poll_init = msm_poll_init,
 858	.poll_get_char	= msm_poll_get_char,
 859	.poll_put_char	= msm_poll_put_char,
 860#endif
 861};
 862
 863static struct msm_port msm_uart_ports[] = {
 864	{
 865		.uart = {
 866			.iotype = UPIO_MEM,
 867			.ops = &msm_uart_pops,
 868			.flags = UPF_BOOT_AUTOCONF,
 869			.fifosize = 64,
 870			.line = 0,
 871		},
 872	},
 873	{
 874		.uart = {
 875			.iotype = UPIO_MEM,
 876			.ops = &msm_uart_pops,
 877			.flags = UPF_BOOT_AUTOCONF,
 878			.fifosize = 64,
 879			.line = 1,
 880		},
 881	},
 882	{
 883		.uart = {
 884			.iotype = UPIO_MEM,
 885			.ops = &msm_uart_pops,
 886			.flags = UPF_BOOT_AUTOCONF,
 887			.fifosize = 64,
 888			.line = 2,
 889		},
 890	},
 891};
 892
 893#define UART_NR	ARRAY_SIZE(msm_uart_ports)
 894
 895static inline struct uart_port *get_port_from_line(unsigned int line)
 896{
 897	return &msm_uart_ports[line].uart;
 898}
 899
 900#ifdef CONFIG_SERIAL_MSM_CONSOLE
 901static void msm_console_write(struct console *co, const char *s,
 902			      unsigned int count)
 903{
 904	int i;
 905	struct uart_port *port;
 906	struct msm_port *msm_port;
 907	int num_newlines = 0;
 908	bool replaced = false;
 
 909
 910	BUG_ON(co->index < 0 || co->index >= UART_NR);
 911
 912	port = get_port_from_line(co->index);
 913	msm_port = UART_TO_MSM(port);
 914
 915	/* Account for newlines that will get a carriage return added */
 916	for (i = 0; i < count; i++)
 917		if (s[i] == '\n')
 918			num_newlines++;
 919	count += num_newlines;
 920
 921	spin_lock(&port->lock);
 922	if (msm_port->is_uartdm)
 923		reset_dm_count(port, count);
 924
 925	i = 0;
 926	while (i < count) {
 927		int j;
 928		unsigned int num_chars;
 929		char buf[4] = { 0 };
 930		unsigned int *bf = (unsigned int *)&buf;
 931
 932		if (msm_port->is_uartdm)
 933			num_chars = min(count - i, (unsigned int)sizeof(buf));
 934		else
 935			num_chars = 1;
 936
 937		for (j = 0; j < num_chars; j++) {
 938			char c = *s;
 939
 940			if (c == '\n' && !replaced) {
 941				buf[j] = '\r';
 942				j++;
 943				replaced = true;
 944			}
 945			if (j < num_chars) {
 946				buf[j] = c;
 947				s++;
 948				replaced = false;
 949			}
 950		}
 951
 952		while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 953			cpu_relax();
 954
 955		msm_write(port, *bf, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
 956		i += num_chars;
 957	}
 958	spin_unlock(&port->lock);
 959}
 960
 961static int __init msm_console_setup(struct console *co, char *options)
 
 962{
 963	struct uart_port *port;
 964	struct msm_port *msm_port;
 965	int baud, flow, bits, parity;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 966
 967	if (unlikely(co->index >= UART_NR || co->index < 0))
 968		return -ENXIO;
 969
 970	port = get_port_from_line(co->index);
 971	msm_port = UART_TO_MSM(port);
 972
 973	if (unlikely(!port->membase))
 974		return -ENXIO;
 975
 976	msm_init_clock(port);
 977
 978	if (options)
 979		uart_parse_options(options, &baud, &parity, &bits, &flow);
 980
 981	bits = 8;
 982	parity = 'n';
 983	flow = 'n';
 984	msm_write(port, UART_MR2_BITS_PER_CHAR_8 | UART_MR2_STOP_BIT_LEN_ONE,
 985		  UART_MR2);	/* 8N1 */
 986
 987	if (baud < 300 || baud > 115200)
 988		baud = 115200;
 989	msm_set_baud_rate(port, baud);
 990
 991	msm_reset(port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 992
 993	if (msm_port->is_uartdm) {
 994		msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
 995		msm_write(port, UART_CR_TX_ENABLE, UART_CR);
 996	}
 997
 998	printk(KERN_INFO "msm_serial: console setup on port #%d\n", port->line);
 
 
 
 
 
 999
1000	return uart_set_options(port, co, baud, parity, bits, flow);
 
1001}
 
 
1002
1003static struct uart_driver msm_uart_driver;
1004
1005static struct console msm_console = {
1006	.name = "ttyMSM",
1007	.write = msm_console_write,
1008	.device = uart_console_device,
1009	.setup = msm_console_setup,
1010	.flags = CON_PRINTBUFFER,
1011	.index = -1,
1012	.data = &msm_uart_driver,
1013};
1014
1015#define MSM_CONSOLE	(&msm_console)
1016
1017#else
1018#define MSM_CONSOLE	NULL
1019#endif
1020
1021static struct uart_driver msm_uart_driver = {
1022	.owner = THIS_MODULE,
1023	.driver_name = "msm_serial",
1024	.dev_name = "ttyMSM",
1025	.nr = UART_NR,
1026	.cons = MSM_CONSOLE,
1027};
1028
1029static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
1030
1031static const struct of_device_id msm_uartdm_table[] = {
1032	{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
1033	{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
1034	{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
1035	{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
1036	{ }
1037};
1038
1039static int __init msm_serial_probe(struct platform_device *pdev)
1040{
1041	struct msm_port *msm_port;
1042	struct resource *resource;
1043	struct uart_port *port;
1044	const struct of_device_id *id;
1045	int irq;
1046
1047	if (pdev->id == -1)
1048		pdev->id = atomic_inc_return(&msm_uart_next_id) - 1;
 
 
1049
1050	if (unlikely(pdev->id < 0 || pdev->id >= UART_NR))
 
 
 
1051		return -ENXIO;
1052
1053	printk(KERN_INFO "msm_serial: detected port #%d\n", pdev->id);
1054
1055	port = get_port_from_line(pdev->id);
1056	port->dev = &pdev->dev;
1057	msm_port = UART_TO_MSM(port);
1058
1059	id = of_match_device(msm_uartdm_table, &pdev->dev);
1060	if (id)
1061		msm_port->is_uartdm = (unsigned long)id->data;
1062	else
1063		msm_port->is_uartdm = 0;
1064
1065	msm_port->clk = devm_clk_get(&pdev->dev, "core");
1066	if (IS_ERR(msm_port->clk))
1067		return PTR_ERR(msm_port->clk);
1068
1069	if (msm_port->is_uartdm) {
1070		msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
1071		if (IS_ERR(msm_port->pclk))
1072			return PTR_ERR(msm_port->pclk);
1073
1074		clk_set_rate(msm_port->clk, 1843200);
1075	}
1076
1077	port->uartclk = clk_get_rate(msm_port->clk);
1078	printk(KERN_INFO "uartclk = %d\n", port->uartclk);
1079
1080
1081	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1082	if (unlikely(!resource))
1083		return -ENXIO;
1084	port->mapbase = resource->start;
1085
1086	irq = platform_get_irq(pdev, 0);
1087	if (unlikely(irq < 0))
1088		return -ENXIO;
1089	port->irq = irq;
1090
1091	platform_set_drvdata(pdev, port);
1092
1093	return uart_add_one_port(&msm_uart_driver, port);
1094}
1095
1096static int msm_serial_remove(struct platform_device *pdev)
1097{
1098	struct uart_port *port = platform_get_drvdata(pdev);
1099
1100	uart_remove_one_port(&msm_uart_driver, port);
1101
1102	return 0;
1103}
1104
1105static struct of_device_id msm_match_table[] = {
1106	{ .compatible = "qcom,msm-uart" },
1107	{ .compatible = "qcom,msm-uartdm" },
1108	{}
1109};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1110
1111static struct platform_driver msm_platform_driver = {
1112	.remove = msm_serial_remove,
 
1113	.driver = {
1114		.name = "msm_serial",
1115		.owner = THIS_MODULE,
1116		.of_match_table = msm_match_table,
1117	},
1118};
1119
1120static int __init msm_serial_init(void)
1121{
1122	int ret;
1123
1124	ret = uart_register_driver(&msm_uart_driver);
1125	if (unlikely(ret))
1126		return ret;
1127
1128	ret = platform_driver_probe(&msm_platform_driver, msm_serial_probe);
1129	if (unlikely(ret))
1130		uart_unregister_driver(&msm_uart_driver);
1131
1132	printk(KERN_INFO "msm_serial: driver initialized\n");
1133
1134	return ret;
1135}
1136
1137static void __exit msm_serial_exit(void)
1138{
1139#ifdef CONFIG_SERIAL_MSM_CONSOLE
1140	unregister_console(&msm_console);
1141#endif
1142	platform_driver_unregister(&msm_platform_driver);
1143	uart_unregister_driver(&msm_uart_driver);
1144}
1145
1146module_init(msm_serial_init);
1147module_exit(msm_serial_exit);
1148
1149MODULE_AUTHOR("Robert Love <rlove@google.com>");
1150MODULE_DESCRIPTION("Driver for msm7x serial device");
1151MODULE_LICENSE("GPL");