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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * SC16IS7xx tty serial driver - common code
   4 *
   5 * Copyright (C) 2014 GridPoint
   6 * Author: Jon Ringle <jringle@gridpoint.com>
   7 * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
   8 */
   9
  10#undef DEFAULT_SYMBOL_NAMESPACE
  11#define DEFAULT_SYMBOL_NAMESPACE "SERIAL_NXP_SC16IS7XX"
  12
  13#include <linux/bits.h>
  14#include <linux/clk.h>
  15#include <linux/delay.h>
  16#include <linux/device.h>
  17#include <linux/export.h>
  18#include <linux/gpio/consumer.h>
  19#include <linux/gpio/driver.h>
  20#include <linux/idr.h>
  21#include <linux/kthread.h>
  22#include <linux/mod_devicetable.h>
  23#include <linux/module.h>
  24#include <linux/property.h>
  25#include <linux/regmap.h>
  26#include <linux/sched.h>
  27#include <linux/serial_core.h>
  28#include <linux/serial.h>
  29#include <linux/string.h>
  30#include <linux/tty.h>
  31#include <linux/tty_flip.h>
  32#include <linux/uaccess.h>
  33#include <linux/units.h>
  34
  35#include "sc16is7xx.h"
  36
  37#define SC16IS7XX_MAX_DEVS		8
  38
  39/* SC16IS7XX register definitions */
  40#define SC16IS7XX_RHR_REG		(0x00) /* RX FIFO */
  41#define SC16IS7XX_THR_REG		(0x00) /* TX FIFO */
  42#define SC16IS7XX_IER_REG		(0x01) /* Interrupt enable */
  43#define SC16IS7XX_IIR_REG		(0x02) /* Interrupt Identification */
  44#define SC16IS7XX_FCR_REG		(0x02) /* FIFO control */
  45#define SC16IS7XX_LCR_REG		(0x03) /* Line Control */
  46#define SC16IS7XX_MCR_REG		(0x04) /* Modem Control */
  47#define SC16IS7XX_LSR_REG		(0x05) /* Line Status */
  48#define SC16IS7XX_MSR_REG		(0x06) /* Modem Status */
  49#define SC16IS7XX_SPR_REG		(0x07) /* Scratch Pad */
  50#define SC16IS7XX_TXLVL_REG		(0x08) /* TX FIFO level */
  51#define SC16IS7XX_RXLVL_REG		(0x09) /* RX FIFO level */
  52#define SC16IS7XX_IODIR_REG		(0x0a) /* I/O Direction
  53						* - only on 75x/76x
  54						*/
  55#define SC16IS7XX_IOSTATE_REG		(0x0b) /* I/O State
  56						* - only on 75x/76x
  57						*/
  58#define SC16IS7XX_IOINTENA_REG		(0x0c) /* I/O Interrupt Enable
  59						* - only on 75x/76x
  60						*/
  61#define SC16IS7XX_IOCONTROL_REG		(0x0e) /* I/O Control
  62						* - only on 75x/76x
  63						*/
  64#define SC16IS7XX_EFCR_REG		(0x0f) /* Extra Features Control */
  65
  66/* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
  67#define SC16IS7XX_TCR_REG		(0x06) /* Transmit control */
  68#define SC16IS7XX_TLR_REG		(0x07) /* Trigger level */
  69
  70/* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
  71#define SC16IS7XX_DLL_REG		(0x00) /* Divisor Latch Low */
  72#define SC16IS7XX_DLH_REG		(0x01) /* Divisor Latch High */
  73
  74/* Enhanced Register set: Only if (LCR == 0xBF) */
  75#define SC16IS7XX_EFR_REG		(0x02) /* Enhanced Features */
  76#define SC16IS7XX_XON1_REG		(0x04) /* Xon1 word */
  77#define SC16IS7XX_XON2_REG		(0x05) /* Xon2 word */
  78#define SC16IS7XX_XOFF1_REG		(0x06) /* Xoff1 word */
  79#define SC16IS7XX_XOFF2_REG		(0x07) /* Xoff2 word */
  80
  81/* IER register bits */
  82#define SC16IS7XX_IER_RDI_BIT		BIT(0)   /* Enable RX data interrupt */
  83#define SC16IS7XX_IER_THRI_BIT		BIT(1)   /* Enable TX holding register
  84						  * interrupt */
  85#define SC16IS7XX_IER_RLSI_BIT		BIT(2)   /* Enable RX line status
  86						  * interrupt */
  87#define SC16IS7XX_IER_MSI_BIT		BIT(3)   /* Enable Modem status
  88						  * interrupt */
  89
  90/* IER register bits - write only if (EFR[4] == 1) */
  91#define SC16IS7XX_IER_SLEEP_BIT		BIT(4)   /* Enable Sleep mode */
  92#define SC16IS7XX_IER_XOFFI_BIT		BIT(5)   /* Enable Xoff interrupt */
  93#define SC16IS7XX_IER_RTSI_BIT		BIT(6)   /* Enable nRTS interrupt */
  94#define SC16IS7XX_IER_CTSI_BIT		BIT(7)   /* Enable nCTS interrupt */
  95
  96/* FCR register bits */
  97#define SC16IS7XX_FCR_FIFO_BIT		BIT(0)   /* Enable FIFO */
  98#define SC16IS7XX_FCR_RXRESET_BIT	BIT(1)   /* Reset RX FIFO */
  99#define SC16IS7XX_FCR_TXRESET_BIT	BIT(2)   /* Reset TX FIFO */
 100#define SC16IS7XX_FCR_RXLVLL_BIT	BIT(6)   /* RX Trigger level LSB */
 101#define SC16IS7XX_FCR_RXLVLH_BIT	BIT(7)   /* RX Trigger level MSB */
 102
 103/* FCR register bits - write only if (EFR[4] == 1) */
 104#define SC16IS7XX_FCR_TXLVLL_BIT	BIT(4)   /* TX Trigger level LSB */
 105#define SC16IS7XX_FCR_TXLVLH_BIT	BIT(5)   /* TX Trigger level MSB */
 106
 107/* IIR register bits */
 108#define SC16IS7XX_IIR_NO_INT_BIT	0x01		/* No interrupts pending */
 109#define SC16IS7XX_IIR_ID_MASK		GENMASK(5, 1)	/* Mask for the interrupt ID */
 110#define SC16IS7XX_IIR_THRI_SRC		0x02		/* TX holding register empty */
 111#define SC16IS7XX_IIR_RDI_SRC		0x04		/* RX data interrupt */
 112#define SC16IS7XX_IIR_RLSE_SRC		0x06		/* RX line status error */
 113#define SC16IS7XX_IIR_RTOI_SRC		0x0c		/* RX time-out interrupt */
 114#define SC16IS7XX_IIR_MSI_SRC		0x00		/* Modem status interrupt
 115							 * - only on 75x/76x
 116							 */
 117#define SC16IS7XX_IIR_INPIN_SRC		0x30		/* Input pin change of state
 118							 * - only on 75x/76x
 119							 */
 120#define SC16IS7XX_IIR_XOFFI_SRC		0x10		/* Received Xoff */
 121#define SC16IS7XX_IIR_CTSRTS_SRC	0x20		/* nCTS,nRTS change of state
 122							 * from active (LOW)
 123							 * to inactive (HIGH)
 124							 */
 125/* LCR register bits */
 126#define SC16IS7XX_LCR_LENGTH0_BIT	BIT(0)   /* Word length bit 0 */
 127#define SC16IS7XX_LCR_LENGTH1_BIT	BIT(1)   /* Word length bit 1
 128						  *
 129						  * Word length bits table:
 130						  * 00 -> 5 bit words
 131						  * 01 -> 6 bit words
 132						  * 10 -> 7 bit words
 133						  * 11 -> 8 bit words
 134						  */
 135#define SC16IS7XX_LCR_STOPLEN_BIT	BIT(2)   /* STOP length bit
 136						  *
 137						  * STOP length bit table:
 138						  * 0 -> 1 stop bit
 139						  * 1 -> 1-1.5 stop bits if
 140						  *      word length is 5,
 141						  *      2 stop bits otherwise
 142						  */
 143#define SC16IS7XX_LCR_PARITY_BIT	BIT(3)   /* Parity bit enable */
 144#define SC16IS7XX_LCR_EVENPARITY_BIT	BIT(4)   /* Even parity bit enable */
 145#define SC16IS7XX_LCR_FORCEPARITY_BIT	BIT(5)   /* 9-bit multidrop parity */
 146#define SC16IS7XX_LCR_TXBREAK_BIT	BIT(6)   /* TX break enable */
 147#define SC16IS7XX_LCR_DLAB_BIT		BIT(7)   /* Divisor Latch enable */
 148#define SC16IS7XX_LCR_WORD_LEN_5	(0x00)
 149#define SC16IS7XX_LCR_WORD_LEN_6	(0x01)
 150#define SC16IS7XX_LCR_WORD_LEN_7	(0x02)
 151#define SC16IS7XX_LCR_WORD_LEN_8	(0x03)
 152#define SC16IS7XX_LCR_CONF_MODE_A	SC16IS7XX_LCR_DLAB_BIT /* Special
 153								* reg set */
 154#define SC16IS7XX_LCR_CONF_MODE_B	0xBF                   /* Enhanced
 155								* reg set */
 156
 157/* MCR register bits */
 158#define SC16IS7XX_MCR_DTR_BIT		BIT(0)   /* DTR complement
 159						  * - only on 75x/76x
 160						  */
 161#define SC16IS7XX_MCR_RTS_BIT		BIT(1)   /* RTS complement */
 162#define SC16IS7XX_MCR_TCRTLR_BIT	BIT(2)   /* TCR/TLR register enable */
 163#define SC16IS7XX_MCR_LOOP_BIT		BIT(4)   /* Enable loopback test mode */
 164#define SC16IS7XX_MCR_XONANY_BIT	BIT(5)   /* Enable Xon Any
 165						  * - write enabled
 166						  * if (EFR[4] == 1)
 167						  */
 168#define SC16IS7XX_MCR_IRDA_BIT		BIT(6)   /* Enable IrDA mode
 169						  * - write enabled
 170						  * if (EFR[4] == 1)
 171						  */
 172#define SC16IS7XX_MCR_CLKSEL_BIT	BIT(7)   /* Divide clock by 4
 173						  * - write enabled
 174						  * if (EFR[4] == 1)
 175						  */
 176
 177/* LSR register bits */
 178#define SC16IS7XX_LSR_DR_BIT		BIT(0)   /* Receiver data ready */
 179#define SC16IS7XX_LSR_OE_BIT		BIT(1)   /* Overrun Error */
 180#define SC16IS7XX_LSR_PE_BIT		BIT(2)   /* Parity Error */
 181#define SC16IS7XX_LSR_FE_BIT		BIT(3)   /* Frame Error */
 182#define SC16IS7XX_LSR_BI_BIT		BIT(4)   /* Break Interrupt */
 183#define SC16IS7XX_LSR_BRK_ERROR_MASK \
 184	(SC16IS7XX_LSR_OE_BIT | \
 185	 SC16IS7XX_LSR_PE_BIT | \
 186	 SC16IS7XX_LSR_FE_BIT | \
 187	 SC16IS7XX_LSR_BI_BIT)
 188
 189#define SC16IS7XX_LSR_THRE_BIT		BIT(5)   /* TX holding register empty */
 190#define SC16IS7XX_LSR_TEMT_BIT		BIT(6)   /* Transmitter empty */
 191#define SC16IS7XX_LSR_FIFOE_BIT		BIT(7)   /* Fifo Error */
 192
 193/* MSR register bits */
 194#define SC16IS7XX_MSR_DCTS_BIT		BIT(0)   /* Delta CTS Clear To Send */
 195#define SC16IS7XX_MSR_DDSR_BIT		BIT(1)   /* Delta DSR Data Set Ready
 196						  * or (IO4)
 197						  * - only on 75x/76x
 198						  */
 199#define SC16IS7XX_MSR_DRI_BIT		BIT(2)   /* Delta RI Ring Indicator
 200						  * or (IO7)
 201						  * - only on 75x/76x
 202						  */
 203#define SC16IS7XX_MSR_DCD_BIT		BIT(3)   /* Delta CD Carrier Detect
 204						  * or (IO6)
 205						  * - only on 75x/76x
 206						  */
 207#define SC16IS7XX_MSR_CTS_BIT		BIT(4)   /* CTS */
 208#define SC16IS7XX_MSR_DSR_BIT		BIT(5)   /* DSR (IO4)
 209						  * - only on 75x/76x
 210						  */
 211#define SC16IS7XX_MSR_RI_BIT		BIT(6)   /* RI (IO7)
 212						  * - only on 75x/76x
 213						  */
 214#define SC16IS7XX_MSR_CD_BIT		BIT(7)   /* CD (IO6)
 215						  * - only on 75x/76x
 216						  */
 217
 218/*
 219 * TCR register bits
 220 * TCR trigger levels are available from 0 to 60 characters with a granularity
 221 * of four.
 222 * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
 223 * no built-in hardware check to make sure this condition is met. Also, the TCR
 224 * must be programmed with this condition before auto RTS or software flow
 225 * control is enabled to avoid spurious operation of the device.
 226 */
 227#define SC16IS7XX_TCR_RX_HALT(words)	((((words) / 4) & 0x0f) << 0)
 228#define SC16IS7XX_TCR_RX_RESUME(words)	((((words) / 4) & 0x0f) << 4)
 229
 230/*
 231 * TLR register bits
 232 * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
 233 * FIFO Control Register (FCR) are used for the transmit and receive FIFO
 234 * trigger levels. Trigger levels from 4 characters to 60 characters are
 235 * available with a granularity of four.
 236 *
 237 * When the trigger level setting in TLR is zero, the SC16IS74x/75x/76x uses the
 238 * trigger level setting defined in FCR. If TLR has non-zero trigger level value
 239 * the trigger level defined in FCR is discarded. This applies to both transmit
 240 * FIFO and receive FIFO trigger level setting.
 241 *
 242 * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
 243 * default state, that is, '00'.
 244 */
 245#define SC16IS7XX_TLR_TX_TRIGGER(words)	((((words) / 4) & 0x0f) << 0)
 246#define SC16IS7XX_TLR_RX_TRIGGER(words)	((((words) / 4) & 0x0f) << 4)
 247
 248/* IOControl register bits (Only 75x/76x) */
 249#define SC16IS7XX_IOCONTROL_LATCH_BIT	BIT(0)   /* Enable input latching */
 250#define SC16IS7XX_IOCONTROL_MODEM_A_BIT	BIT(1)   /* Enable GPIO[7:4] as modem A pins */
 251#define SC16IS7XX_IOCONTROL_MODEM_B_BIT	BIT(2)   /* Enable GPIO[3:0] as modem B pins */
 252#define SC16IS7XX_IOCONTROL_SRESET_BIT	BIT(3)   /* Software Reset */
 253
 254/* EFCR register bits */
 255#define SC16IS7XX_EFCR_9BIT_MODE_BIT	BIT(0)   /* Enable 9-bit or Multidrop
 256						  * mode (RS485) */
 257#define SC16IS7XX_EFCR_RXDISABLE_BIT	BIT(1)   /* Disable receiver */
 258#define SC16IS7XX_EFCR_TXDISABLE_BIT	BIT(2)   /* Disable transmitter */
 259#define SC16IS7XX_EFCR_AUTO_RS485_BIT	BIT(4)   /* Auto RS485 RTS direction */
 260#define SC16IS7XX_EFCR_RTS_INVERT_BIT	BIT(5)   /* RTS output inversion */
 261#define SC16IS7XX_EFCR_IRDA_MODE_BIT	BIT(7)   /* IrDA mode
 262						  * 0 = rate upto 115.2 kbit/s
 263						  *   - Only 75x/76x
 264						  * 1 = rate upto 1.152 Mbit/s
 265						  *   - Only 76x
 266						  */
 267
 268/* EFR register bits */
 269#define SC16IS7XX_EFR_AUTORTS_BIT	BIT(6)   /* Auto RTS flow ctrl enable */
 270#define SC16IS7XX_EFR_AUTOCTS_BIT	BIT(7)   /* Auto CTS flow ctrl enable */
 271#define SC16IS7XX_EFR_XOFF2_DETECT_BIT	BIT(5)   /* Enable Xoff2 detection */
 272#define SC16IS7XX_EFR_ENABLE_BIT	BIT(4)   /* Enable enhanced functions
 273						  * and writing to IER[7:4],
 274						  * FCR[5:4], MCR[7:5]
 275						  */
 276#define SC16IS7XX_EFR_SWFLOW3_BIT	BIT(3)
 277#define SC16IS7XX_EFR_SWFLOW2_BIT	BIT(2)
 278						 /*
 279						  * SWFLOW bits 3 & 2 table:
 280						  * 00 -> no transmitter flow
 281						  *       control
 282						  * 01 -> transmitter generates
 283						  *       XON2 and XOFF2
 284						  * 10 -> transmitter generates
 285						  *       XON1 and XOFF1
 286						  * 11 -> transmitter generates
 287						  *       XON1, XON2, XOFF1 and
 288						  *       XOFF2
 289						  */
 290#define SC16IS7XX_EFR_SWFLOW1_BIT	BIT(1)
 291#define SC16IS7XX_EFR_SWFLOW0_BIT	BIT(0)
 292						 /*
 293						  * SWFLOW bits 1 & 0 table:
 294						  * 00 -> no received flow
 295						  *       control
 296						  * 01 -> receiver compares
 297						  *       XON2 and XOFF2
 298						  * 10 -> receiver compares
 299						  *       XON1 and XOFF1
 300						  * 11 -> receiver compares
 301						  *       XON1, XON2, XOFF1 and
 302						  *       XOFF2
 303						  */
 304#define SC16IS7XX_EFR_FLOWCTRL_BITS	(SC16IS7XX_EFR_AUTORTS_BIT | \
 305					SC16IS7XX_EFR_AUTOCTS_BIT | \
 306					SC16IS7XX_EFR_XOFF2_DETECT_BIT | \
 307					SC16IS7XX_EFR_SWFLOW3_BIT | \
 308					SC16IS7XX_EFR_SWFLOW2_BIT | \
 309					SC16IS7XX_EFR_SWFLOW1_BIT | \
 310					SC16IS7XX_EFR_SWFLOW0_BIT)
 311
 312
 313/* Misc definitions */
 314#define SC16IS7XX_FIFO_SIZE		(64)
 315#define SC16IS7XX_GPIOS_PER_BANK	4
 316
 317#define SC16IS7XX_RECONF_MD		BIT(0)
 318#define SC16IS7XX_RECONF_IER		BIT(1)
 319#define SC16IS7XX_RECONF_RS485		BIT(2)
 320
 321struct sc16is7xx_one_config {
 322	unsigned int			flags;
 323	u8				ier_mask;
 324	u8				ier_val;
 325};
 326
 327struct sc16is7xx_one {
 328	struct uart_port		port;
 329	struct regmap			*regmap;
 330	struct mutex			efr_lock; /* EFR registers access */
 331	struct kthread_work		tx_work;
 332	struct kthread_work		reg_work;
 333	struct kthread_delayed_work	ms_work;
 334	struct sc16is7xx_one_config	config;
 335	unsigned char			buf[SC16IS7XX_FIFO_SIZE]; /* Rx buffer. */
 336	unsigned int			old_mctrl;
 337	u8				old_lcr; /* Value before EFR access. */
 338	bool				irda_mode;
 339};
 340
 341struct sc16is7xx_port {
 342	const struct sc16is7xx_devtype	*devtype;
 343	struct clk			*clk;
 344#ifdef CONFIG_GPIOLIB
 345	struct gpio_chip		gpio;
 346	unsigned long			gpio_valid_mask;
 347#endif
 348	u8				mctrl_mask;
 349	struct kthread_worker		kworker;
 350	struct task_struct		*kworker_task;
 351	struct sc16is7xx_one		p[];
 352};
 353
 354static DEFINE_IDA(sc16is7xx_lines);
 355
 356static struct uart_driver sc16is7xx_uart = {
 357	.owner		= THIS_MODULE,
 358	.driver_name    = SC16IS7XX_NAME,
 359	.dev_name	= "ttySC",
 360	.nr		= SC16IS7XX_MAX_DEVS,
 361};
 362
 363#define to_sc16is7xx_one(p,e)	((container_of((p), struct sc16is7xx_one, e)))
 364
 365static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
 366{
 367	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 368	unsigned int val = 0;
 369
 370	regmap_read(one->regmap, reg, &val);
 371
 372	return val;
 373}
 374
 375static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
 376{
 377	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 378
 379	regmap_write(one->regmap, reg, val);
 380}
 381
 382static void sc16is7xx_fifo_read(struct uart_port *port, u8 *rxbuf, unsigned int rxlen)
 383{
 384	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 385
 386	regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, rxbuf, rxlen);
 387}
 388
 389static void sc16is7xx_fifo_write(struct uart_port *port, u8 *txbuf, u8 to_send)
 390{
 391	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 392
 393	/*
 394	 * Don't send zero-length data, at least on SPI it confuses the chip
 395	 * delivering wrong TXLVL data.
 396	 */
 397	if (unlikely(!to_send))
 398		return;
 399
 400	regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, txbuf, to_send);
 401}
 402
 403static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
 404				  u8 mask, u8 val)
 405{
 406	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 407
 408	regmap_update_bits(one->regmap, reg, mask, val);
 409}
 410
 411static void sc16is7xx_power(struct uart_port *port, int on)
 412{
 413	sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
 414			      SC16IS7XX_IER_SLEEP_BIT,
 415			      on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
 416}
 417
 418/*
 419 * In an amazing feat of design, the Enhanced Features Register (EFR)
 420 * shares the address of the Interrupt Identification Register (IIR).
 421 * Access to EFR is switched on by writing a magic value (0xbf) to the
 422 * Line Control Register (LCR). Any interrupt firing during this time will
 423 * see the EFR where it expects the IIR to be, leading to
 424 * "Unexpected interrupt" messages.
 425 *
 426 * Prevent this possibility by claiming a mutex while accessing the EFR,
 427 * and claiming the same mutex from within the interrupt handler. This is
 428 * similar to disabling the interrupt, but that doesn't work because the
 429 * bulk of the interrupt processing is run as a workqueue job in thread
 430 * context.
 431 */
 432static void sc16is7xx_efr_lock(struct uart_port *port)
 433{
 434	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 435
 436	mutex_lock(&one->efr_lock);
 437
 438	/* Backup content of LCR. */
 439	one->old_lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
 440
 441	/* Enable access to Enhanced register set */
 442	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B);
 443
 444	/* Disable cache updates when writing to EFR registers */
 445	regcache_cache_bypass(one->regmap, true);
 446}
 447
 448static void sc16is7xx_efr_unlock(struct uart_port *port)
 449{
 450	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 451
 452	/* Re-enable cache updates when writing to normal registers */
 453	regcache_cache_bypass(one->regmap, false);
 454
 455	/* Restore original content of LCR */
 456	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, one->old_lcr);
 457
 458	mutex_unlock(&one->efr_lock);
 459}
 460
 461static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
 462{
 463	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 464	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 465
 466	lockdep_assert_held_once(&port->lock);
 467
 468	one->config.flags |= SC16IS7XX_RECONF_IER;
 469	one->config.ier_mask |= bit;
 470	one->config.ier_val &= ~bit;
 471	kthread_queue_work(&s->kworker, &one->reg_work);
 472}
 473
 474static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
 475{
 476	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 477	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 478
 479	lockdep_assert_held_once(&port->lock);
 480
 481	one->config.flags |= SC16IS7XX_RECONF_IER;
 482	one->config.ier_mask |= bit;
 483	one->config.ier_val |= bit;
 484	kthread_queue_work(&s->kworker, &one->reg_work);
 485}
 486
 487static void sc16is7xx_stop_tx(struct uart_port *port)
 488{
 489	sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
 490}
 491
 492static void sc16is7xx_stop_rx(struct uart_port *port)
 493{
 494	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
 495}
 496
 497const struct sc16is7xx_devtype sc16is74x_devtype = {
 498	.name		= "SC16IS74X",
 499	.nr_gpio	= 0,
 500	.nr_uart	= 1,
 501};
 502EXPORT_SYMBOL_GPL(sc16is74x_devtype);
 503
 504const struct sc16is7xx_devtype sc16is750_devtype = {
 505	.name		= "SC16IS750",
 506	.nr_gpio	= 8,
 507	.nr_uart	= 1,
 508};
 509EXPORT_SYMBOL_GPL(sc16is750_devtype);
 510
 511const struct sc16is7xx_devtype sc16is752_devtype = {
 512	.name		= "SC16IS752",
 513	.nr_gpio	= 8,
 514	.nr_uart	= 2,
 515};
 516EXPORT_SYMBOL_GPL(sc16is752_devtype);
 517
 518const struct sc16is7xx_devtype sc16is760_devtype = {
 519	.name		= "SC16IS760",
 520	.nr_gpio	= 8,
 521	.nr_uart	= 1,
 522};
 523EXPORT_SYMBOL_GPL(sc16is760_devtype);
 524
 525const struct sc16is7xx_devtype sc16is762_devtype = {
 526	.name		= "SC16IS762",
 527	.nr_gpio	= 8,
 528	.nr_uart	= 2,
 529};
 530EXPORT_SYMBOL_GPL(sc16is762_devtype);
 531
 532static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
 533{
 534	switch (reg) {
 535	case SC16IS7XX_RHR_REG:
 536	case SC16IS7XX_IIR_REG:
 537	case SC16IS7XX_LSR_REG:
 538	case SC16IS7XX_MSR_REG:
 539	case SC16IS7XX_TXLVL_REG:
 540	case SC16IS7XX_RXLVL_REG:
 541	case SC16IS7XX_IOSTATE_REG:
 542	case SC16IS7XX_IOCONTROL_REG:
 543		return true;
 544	default:
 545		return false;
 546	}
 547}
 548
 549static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
 550{
 551	switch (reg) {
 552	case SC16IS7XX_RHR_REG:
 553		return true;
 554	default:
 555		return false;
 556	}
 557}
 558
 559static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
 560{
 561	return reg == SC16IS7XX_RHR_REG;
 562}
 563
 564/*
 565 * Configure programmable baud rate generator (divisor) according to the
 566 * desired baud rate.
 567 *
 568 * From the datasheet, the divisor is computed according to:
 569 *
 570 *              XTAL1 input frequency
 571 *             -----------------------
 572 *                    prescaler
 573 * divisor = ---------------------------
 574 *            baud-rate x sampling-rate
 575 */
 576static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 577{
 578	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 579	u8 lcr;
 580	unsigned int prescaler = 1;
 581	unsigned long clk = port->uartclk, div = clk / 16 / baud;
 582
 583	if (div >= BIT(16)) {
 584		prescaler = 4;
 585		div /= prescaler;
 586	}
 587
 588	/* Enable enhanced features */
 589	sc16is7xx_efr_lock(port);
 590	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
 591			      SC16IS7XX_EFR_ENABLE_BIT,
 592			      SC16IS7XX_EFR_ENABLE_BIT);
 593	sc16is7xx_efr_unlock(port);
 594
 595	/* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
 596	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
 597			      SC16IS7XX_MCR_CLKSEL_BIT,
 598			      prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
 599
 600	mutex_lock(&one->efr_lock);
 601
 602	/* Backup LCR and access special register set (DLL/DLH) */
 603	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
 604	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
 605			     SC16IS7XX_LCR_CONF_MODE_A);
 606
 607	/* Write the new divisor */
 608	regcache_cache_bypass(one->regmap, true);
 609	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
 610	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
 611	regcache_cache_bypass(one->regmap, false);
 612
 613	/* Restore LCR and access to general register set */
 614	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
 615
 616	mutex_unlock(&one->efr_lock);
 617
 618	return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
 619}
 620
 621static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
 622				unsigned int iir)
 623{
 624	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 625	unsigned int lsr = 0, bytes_read, i;
 626	bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
 627	u8 ch, flag;
 628
 629	if (unlikely(rxlen >= sizeof(one->buf))) {
 630		dev_warn_ratelimited(port->dev,
 631				     "ttySC%i: Possible RX FIFO overrun: %d\n",
 632				     port->line, rxlen);
 633		port->icount.buf_overrun++;
 634		/* Ensure sanity of RX level */
 635		rxlen = sizeof(one->buf);
 636	}
 637
 638	while (rxlen) {
 639		/* Only read lsr if there are possible errors in FIFO */
 640		if (read_lsr) {
 641			lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
 642			if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
 643				read_lsr = false; /* No errors left in FIFO */
 644		} else
 645			lsr = 0;
 646
 647		if (read_lsr) {
 648			one->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
 649			bytes_read = 1;
 650		} else {
 651			sc16is7xx_fifo_read(port, one->buf, rxlen);
 652			bytes_read = rxlen;
 653		}
 654
 655		lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
 656
 657		port->icount.rx++;
 658		flag = TTY_NORMAL;
 659
 660		if (unlikely(lsr)) {
 661			if (lsr & SC16IS7XX_LSR_BI_BIT) {
 662				port->icount.brk++;
 663				if (uart_handle_break(port))
 664					continue;
 665			} else if (lsr & SC16IS7XX_LSR_PE_BIT)
 666				port->icount.parity++;
 667			else if (lsr & SC16IS7XX_LSR_FE_BIT)
 668				port->icount.frame++;
 669			else if (lsr & SC16IS7XX_LSR_OE_BIT)
 670				port->icount.overrun++;
 671
 672			lsr &= port->read_status_mask;
 673			if (lsr & SC16IS7XX_LSR_BI_BIT)
 674				flag = TTY_BREAK;
 675			else if (lsr & SC16IS7XX_LSR_PE_BIT)
 676				flag = TTY_PARITY;
 677			else if (lsr & SC16IS7XX_LSR_FE_BIT)
 678				flag = TTY_FRAME;
 679			else if (lsr & SC16IS7XX_LSR_OE_BIT)
 680				flag = TTY_OVERRUN;
 681		}
 682
 683		for (i = 0; i < bytes_read; ++i) {
 684			ch = one->buf[i];
 685			if (uart_handle_sysrq_char(port, ch))
 686				continue;
 687
 688			if (lsr & port->ignore_status_mask)
 689				continue;
 690
 691			uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
 692					 flag);
 693		}
 694		rxlen -= bytes_read;
 695	}
 696
 697	tty_flip_buffer_push(&port->state->port);
 698}
 699
 700static void sc16is7xx_handle_tx(struct uart_port *port)
 701{
 702	struct tty_port *tport = &port->state->port;
 703	unsigned long flags;
 704	unsigned int txlen;
 705	unsigned char *tail;
 706
 707	if (unlikely(port->x_char)) {
 708		sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
 709		port->icount.tx++;
 710		port->x_char = 0;
 711		return;
 712	}
 713
 714	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
 715		uart_port_lock_irqsave(port, &flags);
 716		sc16is7xx_stop_tx(port);
 717		uart_port_unlock_irqrestore(port, flags);
 718		return;
 719	}
 720
 721	/* Limit to space available in TX FIFO */
 722	txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
 723	if (txlen > SC16IS7XX_FIFO_SIZE) {
 724		dev_err_ratelimited(port->dev,
 725			"chip reports %d free bytes in TX fifo, but it only has %d",
 726			txlen, SC16IS7XX_FIFO_SIZE);
 727		txlen = 0;
 728	}
 729
 730	txlen = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail, txlen);
 731	sc16is7xx_fifo_write(port, tail, txlen);
 732	uart_xmit_advance(port, txlen);
 733
 734	uart_port_lock_irqsave(port, &flags);
 735	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
 736		uart_write_wakeup(port);
 737
 738	if (kfifo_is_empty(&tport->xmit_fifo))
 739		sc16is7xx_stop_tx(port);
 740	else
 741		sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
 742	uart_port_unlock_irqrestore(port, flags);
 743}
 744
 745static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
 746{
 747	u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
 748	unsigned int mctrl = 0;
 749
 750	mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0;
 751	mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0;
 752	mctrl |= (msr & SC16IS7XX_MSR_CD_BIT)  ? TIOCM_CAR : 0;
 753	mctrl |= (msr & SC16IS7XX_MSR_RI_BIT)  ? TIOCM_RNG : 0;
 754	return mctrl;
 755}
 756
 757static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
 758{
 759	struct uart_port *port = &one->port;
 760	unsigned long flags;
 761	unsigned int status, changed;
 762
 763	lockdep_assert_held_once(&one->efr_lock);
 764
 765	status = sc16is7xx_get_hwmctrl(port);
 766	changed = status ^ one->old_mctrl;
 767
 768	if (changed == 0)
 769		return;
 770
 771	one->old_mctrl = status;
 772
 773	uart_port_lock_irqsave(port, &flags);
 774	if ((changed & TIOCM_RNG) && (status & TIOCM_RNG))
 775		port->icount.rng++;
 776	if (changed & TIOCM_DSR)
 777		port->icount.dsr++;
 778	if (changed & TIOCM_CAR)
 779		uart_handle_dcd_change(port, status & TIOCM_CAR);
 780	if (changed & TIOCM_CTS)
 781		uart_handle_cts_change(port, status & TIOCM_CTS);
 782
 783	wake_up_interruptible(&port->state->port.delta_msr_wait);
 784	uart_port_unlock_irqrestore(port, flags);
 785}
 786
 787static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 788{
 789	bool rc = true;
 790	unsigned int iir, rxlen;
 791	struct uart_port *port = &s->p[portno].port;
 792	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 793
 794	mutex_lock(&one->efr_lock);
 795
 796	iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
 797	if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
 798		rc = false;
 799		goto out_port_irq;
 800	}
 801
 802	iir &= SC16IS7XX_IIR_ID_MASK;
 803
 804	switch (iir) {
 805	case SC16IS7XX_IIR_RDI_SRC:
 806	case SC16IS7XX_IIR_RLSE_SRC:
 807	case SC16IS7XX_IIR_RTOI_SRC:
 808	case SC16IS7XX_IIR_XOFFI_SRC:
 809		rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
 810
 811		/*
 812		 * There is a silicon bug that makes the chip report a
 813		 * time-out interrupt but no data in the FIFO. This is
 814		 * described in errata section 18.1.4.
 815		 *
 816		 * When this happens, read one byte from the FIFO to
 817		 * clear the interrupt.
 818		 */
 819		if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
 820			rxlen = 1;
 821
 822		if (rxlen)
 823			sc16is7xx_handle_rx(port, rxlen, iir);
 824		break;
 825		/* CTSRTS interrupt comes only when CTS goes inactive */
 826	case SC16IS7XX_IIR_CTSRTS_SRC:
 827	case SC16IS7XX_IIR_MSI_SRC:
 828		sc16is7xx_update_mlines(one);
 829		break;
 830	case SC16IS7XX_IIR_THRI_SRC:
 831		sc16is7xx_handle_tx(port);
 832		break;
 833	default:
 834		dev_err_ratelimited(port->dev,
 835				    "ttySC%i: Unexpected interrupt: %x",
 836				    port->line, iir);
 837		break;
 838	}
 839
 840out_port_irq:
 841	mutex_unlock(&one->efr_lock);
 842
 843	return rc;
 844}
 845
 846static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
 847{
 848	bool keep_polling;
 849
 850	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
 851
 852	do {
 853		int i;
 854
 855		keep_polling = false;
 856
 857		for (i = 0; i < s->devtype->nr_uart; ++i)
 858			keep_polling |= sc16is7xx_port_irq(s, i);
 859	} while (keep_polling);
 860
 861	return IRQ_HANDLED;
 862}
 863
 864static void sc16is7xx_tx_proc(struct kthread_work *ws)
 865{
 866	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
 867	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 868
 869	if ((port->rs485.flags & SER_RS485_ENABLED) &&
 870	    (port->rs485.delay_rts_before_send > 0))
 871		msleep(port->rs485.delay_rts_before_send);
 872
 873	mutex_lock(&one->efr_lock);
 874	sc16is7xx_handle_tx(port);
 875	mutex_unlock(&one->efr_lock);
 876}
 877
 878static void sc16is7xx_reconf_rs485(struct uart_port *port)
 879{
 880	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |
 881			 SC16IS7XX_EFCR_RTS_INVERT_BIT;
 882	u32 efcr = 0;
 883	struct serial_rs485 *rs485 = &port->rs485;
 884	unsigned long irqflags;
 885
 886	uart_port_lock_irqsave(port, &irqflags);
 887	if (rs485->flags & SER_RS485_ENABLED) {
 888		efcr |=	SC16IS7XX_EFCR_AUTO_RS485_BIT;
 889
 890		if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
 891			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;
 892	}
 893	uart_port_unlock_irqrestore(port, irqflags);
 894
 895	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);
 896}
 897
 898static void sc16is7xx_reg_proc(struct kthread_work *ws)
 899{
 900	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
 901	struct sc16is7xx_one_config config;
 902	unsigned long irqflags;
 903
 904	uart_port_lock_irqsave(&one->port, &irqflags);
 905	config = one->config;
 906	memset(&one->config, 0, sizeof(one->config));
 907	uart_port_unlock_irqrestore(&one->port, irqflags);
 908
 909	if (config.flags & SC16IS7XX_RECONF_MD) {
 910		u8 mcr = 0;
 911
 912		/* Device ignores RTS setting when hardware flow is enabled */
 913		if (one->port.mctrl & TIOCM_RTS)
 914			mcr |= SC16IS7XX_MCR_RTS_BIT;
 915
 916		if (one->port.mctrl & TIOCM_DTR)
 917			mcr |= SC16IS7XX_MCR_DTR_BIT;
 918
 919		if (one->port.mctrl & TIOCM_LOOP)
 920			mcr |= SC16IS7XX_MCR_LOOP_BIT;
 921		sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
 922				      SC16IS7XX_MCR_RTS_BIT |
 923				      SC16IS7XX_MCR_DTR_BIT |
 924				      SC16IS7XX_MCR_LOOP_BIT,
 925				      mcr);
 926	}
 927
 928	if (config.flags & SC16IS7XX_RECONF_IER)
 929		sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,
 930				      config.ier_mask, config.ier_val);
 931
 932	if (config.flags & SC16IS7XX_RECONF_RS485)
 933		sc16is7xx_reconf_rs485(&one->port);
 934}
 935
 936static void sc16is7xx_ms_proc(struct kthread_work *ws)
 937{
 938	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
 939	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
 940
 941	if (one->port.state) {
 942		mutex_lock(&one->efr_lock);
 943		sc16is7xx_update_mlines(one);
 944		mutex_unlock(&one->efr_lock);
 945
 946		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
 947	}
 948}
 949
 950static void sc16is7xx_enable_ms(struct uart_port *port)
 951{
 952	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 953	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 954
 955	lockdep_assert_held_once(&port->lock);
 956
 957	kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0);
 958}
 959
 960static void sc16is7xx_start_tx(struct uart_port *port)
 961{
 962	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 963	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 964
 965	kthread_queue_work(&s->kworker, &one->tx_work);
 966}
 967
 968static void sc16is7xx_throttle(struct uart_port *port)
 969{
 970	unsigned long flags;
 971
 972	/*
 973	 * Hardware flow control is enabled and thus the device ignores RTS
 974	 * value set in MCR register. Stop reading data from RX FIFO so the
 975	 * AutoRTS feature will de-activate RTS output.
 976	 */
 977	uart_port_lock_irqsave(port, &flags);
 978	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
 979	uart_port_unlock_irqrestore(port, flags);
 980}
 981
 982static void sc16is7xx_unthrottle(struct uart_port *port)
 983{
 984	unsigned long flags;
 985
 986	uart_port_lock_irqsave(port, &flags);
 987	sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT);
 988	uart_port_unlock_irqrestore(port, flags);
 989}
 990
 991static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
 992{
 993	unsigned int lsr;
 994
 995	lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
 996
 997	return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0;
 998}
 999
1000static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
1001{
1002	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1003
1004	/* Called with port lock taken so we can only return cached value */
1005	return one->old_mctrl;
1006}
1007
1008static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
1009{
1010	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1011	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1012
1013	one->config.flags |= SC16IS7XX_RECONF_MD;
1014	kthread_queue_work(&s->kworker, &one->reg_work);
1015}
1016
1017static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
1018{
1019	sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
1020			      SC16IS7XX_LCR_TXBREAK_BIT,
1021			      break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
1022}
1023
1024static void sc16is7xx_set_termios(struct uart_port *port,
1025				  struct ktermios *termios,
1026				  const struct ktermios *old)
1027{
1028	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1029	unsigned int lcr, flow = 0;
1030	int baud;
1031	unsigned long flags;
1032
1033	kthread_cancel_delayed_work_sync(&one->ms_work);
1034
1035	/* Mask termios capabilities we don't support */
1036	termios->c_cflag &= ~CMSPAR;
1037
1038	/* Word size */
1039	switch (termios->c_cflag & CSIZE) {
1040	case CS5:
1041		lcr = SC16IS7XX_LCR_WORD_LEN_5;
1042		break;
1043	case CS6:
1044		lcr = SC16IS7XX_LCR_WORD_LEN_6;
1045		break;
1046	case CS7:
1047		lcr = SC16IS7XX_LCR_WORD_LEN_7;
1048		break;
1049	case CS8:
1050		lcr = SC16IS7XX_LCR_WORD_LEN_8;
1051		break;
1052	default:
1053		lcr = SC16IS7XX_LCR_WORD_LEN_8;
1054		termios->c_cflag &= ~CSIZE;
1055		termios->c_cflag |= CS8;
1056		break;
1057	}
1058
1059	/* Parity */
1060	if (termios->c_cflag & PARENB) {
1061		lcr |= SC16IS7XX_LCR_PARITY_BIT;
1062		if (!(termios->c_cflag & PARODD))
1063			lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
1064	}
1065
1066	/* Stop bits */
1067	if (termios->c_cflag & CSTOPB)
1068		lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
1069
1070	/* Set read status mask */
1071	port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
1072	if (termios->c_iflag & INPCK)
1073		port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
1074					  SC16IS7XX_LSR_FE_BIT;
1075	if (termios->c_iflag & (BRKINT | PARMRK))
1076		port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
1077
1078	/* Set status ignore mask */
1079	port->ignore_status_mask = 0;
1080	if (termios->c_iflag & IGNBRK)
1081		port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
1082	if (!(termios->c_cflag & CREAD))
1083		port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
1084
1085	/* Configure flow control */
1086	port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
1087	if (termios->c_cflag & CRTSCTS) {
1088		flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
1089			SC16IS7XX_EFR_AUTORTS_BIT;
1090		port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1091	}
1092	if (termios->c_iflag & IXON)
1093		flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
1094	if (termios->c_iflag & IXOFF)
1095		flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
1096
1097	/* Update LCR register */
1098	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
1099
1100	/* Update EFR registers */
1101	sc16is7xx_efr_lock(port);
1102	sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
1103	sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
1104	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1105			      SC16IS7XX_EFR_FLOWCTRL_BITS, flow);
1106	sc16is7xx_efr_unlock(port);
1107
1108	/* Get baud rate generator configuration */
1109	baud = uart_get_baud_rate(port, termios, old,
1110				  port->uartclk / 16 / 4 / 0xffff,
1111				  port->uartclk / 16);
1112
1113	/* Setup baudrate generator */
1114	baud = sc16is7xx_set_baud(port, baud);
1115
1116	uart_port_lock_irqsave(port, &flags);
1117
1118	/* Update timeout according to new baud rate */
1119	uart_update_timeout(port, termios->c_cflag, baud);
1120
1121	if (UART_ENABLE_MS(port, termios->c_cflag))
1122		sc16is7xx_enable_ms(port);
1123
1124	uart_port_unlock_irqrestore(port, flags);
1125}
1126
1127static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios,
1128				  struct serial_rs485 *rs485)
1129{
1130	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1131	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1132
1133	if (rs485->flags & SER_RS485_ENABLED) {
1134		/*
1135		 * RTS signal is handled by HW, it's timing can't be influenced.
1136		 * However, it's sometimes useful to delay TX even without RTS
1137		 * control therefore we try to handle .delay_rts_before_send.
1138		 */
1139		if (rs485->delay_rts_after_send)
1140			return -EINVAL;
1141	}
1142
1143	one->config.flags |= SC16IS7XX_RECONF_RS485;
1144	kthread_queue_work(&s->kworker, &one->reg_work);
1145
1146	return 0;
1147}
1148
1149static int sc16is7xx_startup(struct uart_port *port)
1150{
1151	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1152	unsigned int val;
1153	unsigned long flags;
1154
1155	sc16is7xx_power(port, 1);
1156
1157	/* Reset FIFOs*/
1158	val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
1159	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
1160	udelay(5);
1161	sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
1162			     SC16IS7XX_FCR_FIFO_BIT);
1163
1164	/* Enable EFR */
1165	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
1166			     SC16IS7XX_LCR_CONF_MODE_B);
1167
1168	regcache_cache_bypass(one->regmap, true);
1169
1170	/* Enable write access to enhanced features and internal clock div */
1171	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
1172			      SC16IS7XX_EFR_ENABLE_BIT,
1173			      SC16IS7XX_EFR_ENABLE_BIT);
1174
1175	/* Enable TCR/TLR */
1176	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1177			      SC16IS7XX_MCR_TCRTLR_BIT,
1178			      SC16IS7XX_MCR_TCRTLR_BIT);
1179
1180	/* Configure flow control levels */
1181	/* Flow control halt level 48, resume level 24 */
1182	sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
1183			     SC16IS7XX_TCR_RX_RESUME(24) |
1184			     SC16IS7XX_TCR_RX_HALT(48));
1185
1186	regcache_cache_bypass(one->regmap, false);
1187
1188	/* Now, initialize the UART */
1189	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
1190
1191	/* Enable IrDA mode if requested in DT */
1192	/* This bit must be written with LCR[7] = 0 */
1193	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
1194			      SC16IS7XX_MCR_IRDA_BIT,
1195			      one->irda_mode ?
1196				SC16IS7XX_MCR_IRDA_BIT : 0);
1197
1198	/* Enable the Rx and Tx FIFO */
1199	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1200			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1201			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1202			      0);
1203
1204	/* Enable RX, CTS change and modem lines interrupts */
1205	val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT |
1206	      SC16IS7XX_IER_MSI_BIT;
1207	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
1208
1209	/* Enable modem status polling */
1210	uart_port_lock_irqsave(port, &flags);
1211	sc16is7xx_enable_ms(port);
1212	uart_port_unlock_irqrestore(port, flags);
1213
1214	return 0;
1215}
1216
1217static void sc16is7xx_shutdown(struct uart_port *port)
1218{
1219	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1220	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
1221
1222	kthread_cancel_delayed_work_sync(&one->ms_work);
1223
1224	/* Disable all interrupts */
1225	sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
1226	/* Disable TX/RX */
1227	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
1228			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1229			      SC16IS7XX_EFCR_TXDISABLE_BIT,
1230			      SC16IS7XX_EFCR_RXDISABLE_BIT |
1231			      SC16IS7XX_EFCR_TXDISABLE_BIT);
1232
1233	sc16is7xx_power(port, 0);
1234
1235	kthread_flush_worker(&s->kworker);
1236}
1237
1238static const char *sc16is7xx_type(struct uart_port *port)
1239{
1240	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
1241
1242	return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
1243}
1244
1245static int sc16is7xx_request_port(struct uart_port *port)
1246{
1247	/* Do nothing */
1248	return 0;
1249}
1250
1251static void sc16is7xx_config_port(struct uart_port *port, int flags)
1252{
1253	if (flags & UART_CONFIG_TYPE)
1254		port->type = PORT_SC16IS7XX;
1255}
1256
1257static int sc16is7xx_verify_port(struct uart_port *port,
1258				 struct serial_struct *s)
1259{
1260	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
1261		return -EINVAL;
1262	if (s->irq != port->irq)
1263		return -EINVAL;
1264
1265	return 0;
1266}
1267
1268static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
1269			 unsigned int oldstate)
1270{
1271	sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
1272}
1273
1274static void sc16is7xx_null_void(struct uart_port *port)
1275{
1276	/* Do nothing */
1277}
1278
1279static const struct uart_ops sc16is7xx_ops = {
1280	.tx_empty	= sc16is7xx_tx_empty,
1281	.set_mctrl	= sc16is7xx_set_mctrl,
1282	.get_mctrl	= sc16is7xx_get_mctrl,
1283	.stop_tx	= sc16is7xx_stop_tx,
1284	.start_tx	= sc16is7xx_start_tx,
1285	.throttle	= sc16is7xx_throttle,
1286	.unthrottle	= sc16is7xx_unthrottle,
1287	.stop_rx	= sc16is7xx_stop_rx,
1288	.enable_ms	= sc16is7xx_enable_ms,
1289	.break_ctl	= sc16is7xx_break_ctl,
1290	.startup	= sc16is7xx_startup,
1291	.shutdown	= sc16is7xx_shutdown,
1292	.set_termios	= sc16is7xx_set_termios,
1293	.type		= sc16is7xx_type,
1294	.request_port	= sc16is7xx_request_port,
1295	.release_port	= sc16is7xx_null_void,
1296	.config_port	= sc16is7xx_config_port,
1297	.verify_port	= sc16is7xx_verify_port,
1298	.pm		= sc16is7xx_pm,
1299};
1300
1301#ifdef CONFIG_GPIOLIB
1302static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1303{
1304	unsigned int val;
1305	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1306	struct uart_port *port = &s->p[0].port;
1307
1308	val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1309
1310	return !!(val & BIT(offset));
1311}
1312
1313static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1314{
1315	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1316	struct uart_port *port = &s->p[0].port;
1317
1318	sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1319			      val ? BIT(offset) : 0);
1320}
1321
1322static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1323					  unsigned offset)
1324{
1325	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1326	struct uart_port *port = &s->p[0].port;
1327
1328	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1329
1330	return 0;
1331}
1332
1333static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1334					   unsigned offset, int val)
1335{
1336	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1337	struct uart_port *port = &s->p[0].port;
1338	u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1339
1340	if (val)
1341		state |= BIT(offset);
1342	else
1343		state &= ~BIT(offset);
1344
1345	/*
1346	 * If we write IOSTATE first, and then IODIR, the output value is not
1347	 * transferred to the corresponding I/O pin.
1348	 * The datasheet states that each register bit will be transferred to
1349	 * the corresponding I/O pin programmed as output when writing to
1350	 * IOSTATE. Therefore, configure direction first with IODIR, and then
1351	 * set value after with IOSTATE.
1352	 */
1353	sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1354			      BIT(offset));
1355	sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
1356
1357	return 0;
1358}
1359
1360static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip,
1361					  unsigned long *valid_mask,
1362					  unsigned int ngpios)
1363{
1364	struct sc16is7xx_port *s = gpiochip_get_data(chip);
1365
1366	*valid_mask = s->gpio_valid_mask;
1367
1368	return 0;
1369}
1370
1371static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
1372{
1373	struct device *dev = s->p[0].port.dev;
1374
1375	if (!s->devtype->nr_gpio)
1376		return 0;
1377
1378	switch (s->mctrl_mask) {
1379	case 0:
1380		s->gpio_valid_mask = GENMASK(7, 0);
1381		break;
1382	case SC16IS7XX_IOCONTROL_MODEM_A_BIT:
1383		s->gpio_valid_mask = GENMASK(3, 0);
1384		break;
1385	case SC16IS7XX_IOCONTROL_MODEM_B_BIT:
1386		s->gpio_valid_mask = GENMASK(7, 4);
1387		break;
1388	default:
1389		break;
1390	}
1391
1392	if (s->gpio_valid_mask == 0)
1393		return 0;
1394
1395	s->gpio.owner		 = THIS_MODULE;
1396	s->gpio.parent		 = dev;
1397	s->gpio.label		 = dev_name(dev);
1398	s->gpio.init_valid_mask	 = sc16is7xx_gpio_init_valid_mask;
1399	s->gpio.direction_input	 = sc16is7xx_gpio_direction_input;
1400	s->gpio.get		 = sc16is7xx_gpio_get;
1401	s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1402	s->gpio.set		 = sc16is7xx_gpio_set;
1403	s->gpio.base		 = -1;
1404	s->gpio.ngpio		 = s->devtype->nr_gpio;
1405	s->gpio.can_sleep	 = 1;
1406
1407	return gpiochip_add_data(&s->gpio, s);
1408}
1409#endif
1410
1411static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
1412{
1413	int i;
1414	int ret;
1415	int count;
1416	u32 irda_port[SC16IS7XX_MAX_PORTS];
1417	struct device *dev = s->p[0].port.dev;
1418
1419	count = device_property_count_u32(dev, "irda-mode-ports");
1420	if (count < 0 || count > ARRAY_SIZE(irda_port))
1421		return;
1422
1423	ret = device_property_read_u32_array(dev, "irda-mode-ports",
1424					     irda_port, count);
1425	if (ret)
1426		return;
1427
1428	for (i = 0; i < count; i++) {
1429		if (irda_port[i] < s->devtype->nr_uart)
1430			s->p[irda_port[i]].irda_mode = true;
1431	}
1432}
1433
1434/*
1435 * Configure ports designated to operate as modem control lines.
1436 */
1437static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
1438				       struct regmap *regmap)
1439{
1440	int i;
1441	int ret;
1442	int count;
1443	u32 mctrl_port[SC16IS7XX_MAX_PORTS];
1444	struct device *dev = s->p[0].port.dev;
1445
1446	count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
1447	if (count < 0 || count > ARRAY_SIZE(mctrl_port))
1448		return 0;
1449
1450	ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports",
1451					     mctrl_port, count);
1452	if (ret)
1453		return ret;
1454
1455	s->mctrl_mask = 0;
1456
1457	for (i = 0; i < count; i++) {
1458		/* Use GPIO lines as modem control lines */
1459		if (mctrl_port[i] == 0)
1460			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
1461		else if (mctrl_port[i] == 1)
1462			s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
1463	}
1464
1465	if (s->mctrl_mask)
1466		regmap_update_bits(
1467			regmap,
1468			SC16IS7XX_IOCONTROL_REG,
1469			SC16IS7XX_IOCONTROL_MODEM_A_BIT |
1470			SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
1471
1472	return 0;
1473}
1474
1475static const struct serial_rs485 sc16is7xx_rs485_supported = {
1476	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
1477	.delay_rts_before_send = 1,
1478	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
1479};
1480
1481/* Reset device, purging any pending irq / data */
1482static int sc16is7xx_reset(struct device *dev, struct regmap *regmap)
1483{
1484	struct gpio_desc *reset_gpio;
1485
1486	/* Assert reset GPIO if defined and valid. */
1487	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
1488	if (IS_ERR(reset_gpio))
1489		return dev_err_probe(dev, PTR_ERR(reset_gpio), "Failed to get reset GPIO\n");
1490
1491	if (reset_gpio) {
1492		/* The minimum reset pulse width is 3 us. */
1493		fsleep(5);
1494		gpiod_set_value_cansleep(reset_gpio, 0); /* Deassert GPIO */
1495	} else {
1496		/* Software reset */
1497		regmap_write(regmap, SC16IS7XX_IOCONTROL_REG,
1498			     SC16IS7XX_IOCONTROL_SRESET_BIT);
1499	}
1500
1501	return 0;
1502}
1503
1504int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
1505		    struct regmap *regmaps[], int irq)
1506{
1507	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
1508	unsigned int val;
1509	u32 uartclk = 0;
1510	int i, ret;
1511	struct sc16is7xx_port *s;
1512	bool port_registered[SC16IS7XX_MAX_PORTS];
1513
1514	for (i = 0; i < devtype->nr_uart; i++)
1515		if (IS_ERR(regmaps[i]))
1516			return PTR_ERR(regmaps[i]);
1517
1518	/*
1519	 * This device does not have an identification register that would
1520	 * tell us if we are really connected to the correct device.
1521	 * The best we can do is to check if communication is at all possible.
1522	 *
1523	 * Note: regmap[0] is used in the probe function to access registers
1524	 * common to all channels/ports, as it is guaranteed to be present on
1525	 * all variants.
1526	 */
1527	ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
1528	if (ret < 0)
1529		return -EPROBE_DEFER;
1530
1531	/* Alloc port structure */
1532	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
1533	if (!s) {
1534		dev_err(dev, "Error allocating port structure\n");
1535		return -ENOMEM;
1536	}
1537
1538	/* Always ask for fixed clock rate from a property. */
1539	device_property_read_u32(dev, "clock-frequency", &uartclk);
1540
1541	s->clk = devm_clk_get_optional(dev, NULL);
1542	if (IS_ERR(s->clk))
1543		return PTR_ERR(s->clk);
1544
1545	ret = clk_prepare_enable(s->clk);
1546	if (ret)
1547		return ret;
1548
1549	freq = clk_get_rate(s->clk);
1550	if (freq == 0) {
1551		if (uartclk)
1552			freq = uartclk;
1553		if (pfreq)
1554			freq = *pfreq;
1555		if (freq)
1556			dev_dbg(dev, "Clock frequency: %luHz\n", freq);
1557		else
1558			return -EINVAL;
1559	}
1560
1561	s->devtype = devtype;
1562	dev_set_drvdata(dev, s);
1563
1564	kthread_init_worker(&s->kworker);
1565	s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
1566				      "sc16is7xx");
1567	if (IS_ERR(s->kworker_task)) {
1568		ret = PTR_ERR(s->kworker_task);
1569		goto out_clk;
1570	}
1571	sched_set_fifo(s->kworker_task);
1572
1573	ret = sc16is7xx_reset(dev, regmaps[0]);
1574	if (ret)
1575		goto out_kthread;
1576
1577	/* Mark each port line and status as uninitialised. */
1578	for (i = 0; i < devtype->nr_uart; ++i) {
1579		s->p[i].port.line = SC16IS7XX_MAX_DEVS;
1580		port_registered[i] = false;
1581	}
1582
1583	for (i = 0; i < devtype->nr_uart; ++i) {
1584		ret = ida_alloc_max(&sc16is7xx_lines,
1585				    SC16IS7XX_MAX_DEVS - 1, GFP_KERNEL);
1586		if (ret < 0)
1587			goto out_ports;
1588
1589		s->p[i].port.line = ret;
1590
1591		/* Initialize port data */
1592		s->p[i].port.dev	= dev;
1593		s->p[i].port.irq	= irq;
1594		s->p[i].port.type	= PORT_SC16IS7XX;
1595		s->p[i].port.fifosize	= SC16IS7XX_FIFO_SIZE;
1596		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1597		s->p[i].port.iobase	= i;
1598		/*
1599		 * Use all ones as membase to make sure uart_configure_port() in
1600		 * serial_core.c does not abort for SPI/I2C devices where the
1601		 * membase address is not applicable.
1602		 */
1603		s->p[i].port.membase	= (void __iomem *)~0;
1604		s->p[i].port.iotype	= UPIO_PORT;
1605		s->p[i].port.uartclk	= freq;
1606		s->p[i].port.rs485_config = sc16is7xx_config_rs485;
1607		s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
1608		s->p[i].port.ops	= &sc16is7xx_ops;
1609		s->p[i].old_mctrl	= 0;
1610		s->p[i].regmap		= regmaps[i];
1611
1612		mutex_init(&s->p[i].efr_lock);
1613
1614		ret = uart_get_rs485_mode(&s->p[i].port);
1615		if (ret)
1616			goto out_ports;
1617
1618		/* Disable all interrupts */
1619		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1620		/* Disable TX/RX */
1621		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1622				     SC16IS7XX_EFCR_RXDISABLE_BIT |
1623				     SC16IS7XX_EFCR_TXDISABLE_BIT);
1624
1625		/* Initialize kthread work structs */
1626		kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
1627		kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
1628		kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
1629
1630		/* Register port */
1631		ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
1632		if (ret)
1633			goto out_ports;
1634
1635		port_registered[i] = true;
1636
1637		/* Enable EFR */
1638		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
1639				     SC16IS7XX_LCR_CONF_MODE_B);
1640
1641		regcache_cache_bypass(regmaps[i], true);
1642
1643		/* Enable write access to enhanced features */
1644		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
1645				     SC16IS7XX_EFR_ENABLE_BIT);
1646
1647		regcache_cache_bypass(regmaps[i], false);
1648
1649		/* Restore access to general registers */
1650		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
1651
1652		/* Go to suspend mode */
1653		sc16is7xx_power(&s->p[i].port, 0);
1654	}
1655
1656	sc16is7xx_setup_irda_ports(s);
1657
1658	ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
1659	if (ret)
1660		goto out_ports;
1661
1662#ifdef CONFIG_GPIOLIB
1663	ret = sc16is7xx_setup_gpio_chip(s);
1664	if (ret)
1665		goto out_ports;
1666#endif
1667
1668	/*
1669	 * Setup interrupt. We first try to acquire the IRQ line as level IRQ.
1670	 * If that succeeds, we can allow sharing the interrupt as well.
1671	 * In case the interrupt controller doesn't support that, we fall
1672	 * back to a non-shared falling-edge trigger.
1673	 */
1674	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1675					IRQF_TRIGGER_LOW | IRQF_SHARED |
1676					IRQF_ONESHOT,
1677					dev_name(dev), s);
1678	if (!ret)
1679		return 0;
1680
1681	ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
1682					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1683					dev_name(dev), s);
1684	if (!ret)
1685		return 0;
1686
1687#ifdef CONFIG_GPIOLIB
1688	if (s->gpio_valid_mask)
1689		gpiochip_remove(&s->gpio);
1690#endif
1691
1692out_ports:
1693	for (i = 0; i < devtype->nr_uart; i++) {
1694		if (s->p[i].port.line < SC16IS7XX_MAX_DEVS)
1695			ida_free(&sc16is7xx_lines, s->p[i].port.line);
1696		if (port_registered[i])
1697			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1698	}
1699
1700out_kthread:
1701	kthread_stop(s->kworker_task);
1702
1703out_clk:
1704	clk_disable_unprepare(s->clk);
1705
1706	return ret;
1707}
1708EXPORT_SYMBOL_GPL(sc16is7xx_probe);
1709
1710void sc16is7xx_remove(struct device *dev)
1711{
1712	struct sc16is7xx_port *s = dev_get_drvdata(dev);
1713	int i;
1714
1715#ifdef CONFIG_GPIOLIB
1716	if (s->gpio_valid_mask)
1717		gpiochip_remove(&s->gpio);
1718#endif
1719
1720	for (i = 0; i < s->devtype->nr_uart; i++) {
1721		kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
1722		ida_free(&sc16is7xx_lines, s->p[i].port.line);
1723		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
1724		sc16is7xx_power(&s->p[i].port, 0);
1725	}
1726
1727	kthread_flush_worker(&s->kworker);
1728	kthread_stop(s->kworker_task);
1729
1730	clk_disable_unprepare(s->clk);
1731}
1732EXPORT_SYMBOL_GPL(sc16is7xx_remove);
1733
1734const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1735	{ .compatible = "nxp,sc16is740",	.data = &sc16is74x_devtype, },
1736	{ .compatible = "nxp,sc16is741",	.data = &sc16is74x_devtype, },
1737	{ .compatible = "nxp,sc16is750",	.data = &sc16is750_devtype, },
1738	{ .compatible = "nxp,sc16is752",	.data = &sc16is752_devtype, },
1739	{ .compatible = "nxp,sc16is760",	.data = &sc16is760_devtype, },
1740	{ .compatible = "nxp,sc16is762",	.data = &sc16is762_devtype, },
1741	{ }
1742};
1743EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
1744MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1745
1746const struct regmap_config sc16is7xx_regcfg = {
1747	.reg_bits = 5,
1748	.pad_bits = 3,
1749	.val_bits = 8,
1750	.cache_type = REGCACHE_MAPLE,
1751	.volatile_reg = sc16is7xx_regmap_volatile,
1752	.precious_reg = sc16is7xx_regmap_precious,
1753	.writeable_noinc_reg = sc16is7xx_regmap_noinc,
1754	.readable_noinc_reg = sc16is7xx_regmap_noinc,
1755	.max_raw_read = SC16IS7XX_FIFO_SIZE,
1756	.max_raw_write = SC16IS7XX_FIFO_SIZE,
1757	.max_register = SC16IS7XX_EFCR_REG,
1758};
1759EXPORT_SYMBOL_GPL(sc16is7xx_regcfg);
1760
1761const char *sc16is7xx_regmap_name(u8 port_id)
1762{
1763	switch (port_id) {
1764	case 0:	return "port0";
1765	case 1:	return "port1";
1766	default:
1767		WARN_ON(true);
1768		return NULL;
1769	}
1770}
1771EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name);
1772
1773unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
1774{
1775	/* CH1,CH0 are at bits 2:1. */
1776	return port_id << 1;
1777}
1778EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask);
1779
1780static int __init sc16is7xx_init(void)
1781{
1782	return uart_register_driver(&sc16is7xx_uart);
1783}
1784module_init(sc16is7xx_init);
1785
1786static void __exit sc16is7xx_exit(void)
1787{
1788	uart_unregister_driver(&sc16is7xx_uart);
1789}
1790module_exit(sc16is7xx_exit);
1791
1792MODULE_LICENSE("GPL");
1793MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1794MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");