1// SPDX-License-Identifier: GPL-2.0
   2//
   3// STMicroelectronics STM32 SPI Controller driver (master mode only)
   4//
   5// Copyright (C) 2017, STMicroelectronics - All Rights Reserved
   6// Author(s): Amelie Delaunay <amelie.delaunay@st.com> for STMicroelectronics.
   7
   8#include <linux/bitfield.h>
   9#include <linux/debugfs.h>
  10#include <linux/clk.h>
  11#include <linux/delay.h>
  12#include <linux/dmaengine.h>
  13#include <linux/interrupt.h>
  14#include <linux/iopoll.h>
  15#include <linux/module.h>
  16#include <linux/of_platform.h>
  17#include <linux/pinctrl/consumer.h>
  18#include <linux/pm_runtime.h>
  19#include <linux/reset.h>
  20#include <linux/spi/spi.h>
  21
  22#define DRIVER_NAME "spi_stm32"
  23
  24/* STM32F4 SPI registers */
  25#define STM32F4_SPI_CR1			0x00
  26#define STM32F4_SPI_CR2			0x04
  27#define STM32F4_SPI_SR			0x08
  28#define STM32F4_SPI_DR			0x0C
  29#define STM32F4_SPI_I2SCFGR		0x1C
  30
  31/* STM32F4_SPI_CR1 bit fields */
  32#define STM32F4_SPI_CR1_CPHA		BIT(0)
  33#define STM32F4_SPI_CR1_CPOL		BIT(1)
  34#define STM32F4_SPI_CR1_MSTR		BIT(2)
  35#define STM32F4_SPI_CR1_BR_SHIFT	3
  36#define STM32F4_SPI_CR1_BR		GENMASK(5, 3)
  37#define STM32F4_SPI_CR1_SPE		BIT(6)
  38#define STM32F4_SPI_CR1_LSBFRST		BIT(7)
  39#define STM32F4_SPI_CR1_SSI		BIT(8)
  40#define STM32F4_SPI_CR1_SSM		BIT(9)
  41#define STM32F4_SPI_CR1_RXONLY		BIT(10)
  42#define STM32F4_SPI_CR1_DFF		BIT(11)
  43#define STM32F4_SPI_CR1_CRCNEXT		BIT(12)
  44#define STM32F4_SPI_CR1_CRCEN		BIT(13)
  45#define STM32F4_SPI_CR1_BIDIOE		BIT(14)
  46#define STM32F4_SPI_CR1_BIDIMODE	BIT(15)
  47#define STM32F4_SPI_CR1_BR_MIN		0
  48#define STM32F4_SPI_CR1_BR_MAX		(GENMASK(5, 3) >> 3)
  49
  50/* STM32F4_SPI_CR2 bit fields */
  51#define STM32F4_SPI_CR2_RXDMAEN		BIT(0)
  52#define STM32F4_SPI_CR2_TXDMAEN		BIT(1)
  53#define STM32F4_SPI_CR2_SSOE		BIT(2)
  54#define STM32F4_SPI_CR2_FRF		BIT(4)
  55#define STM32F4_SPI_CR2_ERRIE		BIT(5)
  56#define STM32F4_SPI_CR2_RXNEIE		BIT(6)
  57#define STM32F4_SPI_CR2_TXEIE		BIT(7)
  58
  59/* STM32F4_SPI_SR bit fields */
  60#define STM32F4_SPI_SR_RXNE		BIT(0)
  61#define STM32F4_SPI_SR_TXE		BIT(1)
  62#define STM32F4_SPI_SR_CHSIDE		BIT(2)
  63#define STM32F4_SPI_SR_UDR		BIT(3)
  64#define STM32F4_SPI_SR_CRCERR		BIT(4)
  65#define STM32F4_SPI_SR_MODF		BIT(5)
  66#define STM32F4_SPI_SR_OVR		BIT(6)
  67#define STM32F4_SPI_SR_BSY		BIT(7)
  68#define STM32F4_SPI_SR_FRE		BIT(8)
  69
  70/* STM32F4_SPI_I2SCFGR bit fields */
  71#define STM32F4_SPI_I2SCFGR_I2SMOD	BIT(11)
  72
  73/* STM32F4 SPI Baud Rate min/max divisor */
  74#define STM32F4_SPI_BR_DIV_MIN		(2 << STM32F4_SPI_CR1_BR_MIN)
  75#define STM32F4_SPI_BR_DIV_MAX		(2 << STM32F4_SPI_CR1_BR_MAX)
  76
  77/* STM32H7 SPI registers */
  78#define STM32H7_SPI_CR1			0x00
  79#define STM32H7_SPI_CR2			0x04
  80#define STM32H7_SPI_CFG1		0x08
  81#define STM32H7_SPI_CFG2		0x0C
  82#define STM32H7_SPI_IER			0x10
  83#define STM32H7_SPI_SR			0x14
  84#define STM32H7_SPI_IFCR		0x18
  85#define STM32H7_SPI_TXDR		0x20
  86#define STM32H7_SPI_RXDR		0x30
  87#define STM32H7_SPI_I2SCFGR		0x50
  88
  89/* STM32H7_SPI_CR1 bit fields */
  90#define STM32H7_SPI_CR1_SPE		BIT(0)
  91#define STM32H7_SPI_CR1_MASRX		BIT(8)
  92#define STM32H7_SPI_CR1_CSTART		BIT(9)
  93#define STM32H7_SPI_CR1_CSUSP		BIT(10)
  94#define STM32H7_SPI_CR1_HDDIR		BIT(11)
  95#define STM32H7_SPI_CR1_SSI		BIT(12)
  96
  97/* STM32H7_SPI_CR2 bit fields */
  98#define STM32H7_SPI_CR2_TSIZE		GENMASK(15, 0)
  99#define STM32H7_SPI_TSIZE_MAX		GENMASK(15, 0)
 100
 101/* STM32H7_SPI_CFG1 bit fields */
 102#define STM32H7_SPI_CFG1_DSIZE		GENMASK(4, 0)
 103#define STM32H7_SPI_CFG1_FTHLV		GENMASK(8, 5)
 104#define STM32H7_SPI_CFG1_RXDMAEN	BIT(14)
 105#define STM32H7_SPI_CFG1_TXDMAEN	BIT(15)
 106#define STM32H7_SPI_CFG1_MBR		GENMASK(30, 28)
 107#define STM32H7_SPI_CFG1_MBR_SHIFT	28
 108#define STM32H7_SPI_CFG1_MBR_MIN	0
 109#define STM32H7_SPI_CFG1_MBR_MAX	(GENMASK(30, 28) >> 28)
 110
 111/* STM32H7_SPI_CFG2 bit fields */
 112#define STM32H7_SPI_CFG2_MIDI		GENMASK(7, 4)
 113#define STM32H7_SPI_CFG2_COMM		GENMASK(18, 17)
 114#define STM32H7_SPI_CFG2_SP		GENMASK(21, 19)
 115#define STM32H7_SPI_CFG2_MASTER		BIT(22)
 116#define STM32H7_SPI_CFG2_LSBFRST	BIT(23)
 117#define STM32H7_SPI_CFG2_CPHA		BIT(24)
 118#define STM32H7_SPI_CFG2_CPOL		BIT(25)
 119#define STM32H7_SPI_CFG2_SSM		BIT(26)
 120#define STM32H7_SPI_CFG2_AFCNTR		BIT(31)
 121
 122/* STM32H7_SPI_IER bit fields */
 123#define STM32H7_SPI_IER_RXPIE		BIT(0)
 124#define STM32H7_SPI_IER_TXPIE		BIT(1)
 125#define STM32H7_SPI_IER_DXPIE		BIT(2)
 126#define STM32H7_SPI_IER_EOTIE		BIT(3)
 127#define STM32H7_SPI_IER_TXTFIE		BIT(4)
 128#define STM32H7_SPI_IER_OVRIE		BIT(6)
 129#define STM32H7_SPI_IER_MODFIE		BIT(9)
 130#define STM32H7_SPI_IER_ALL		GENMASK(10, 0)
 131
 132/* STM32H7_SPI_SR bit fields */
 133#define STM32H7_SPI_SR_RXP		BIT(0)
 134#define STM32H7_SPI_SR_TXP		BIT(1)
 135#define STM32H7_SPI_SR_EOT		BIT(3)
 136#define STM32H7_SPI_SR_OVR		BIT(6)
 137#define STM32H7_SPI_SR_MODF		BIT(9)
 138#define STM32H7_SPI_SR_SUSP		BIT(11)
 139#define STM32H7_SPI_SR_RXPLVL		GENMASK(14, 13)
 140#define STM32H7_SPI_SR_RXWNE		BIT(15)
 141
 142/* STM32H7_SPI_IFCR bit fields */
 143#define STM32H7_SPI_IFCR_ALL		GENMASK(11, 3)
 144
 145/* STM32H7_SPI_I2SCFGR bit fields */
 146#define STM32H7_SPI_I2SCFGR_I2SMOD	BIT(0)
 147
 148/* STM32H7 SPI Master Baud Rate min/max divisor */
 149#define STM32H7_SPI_MBR_DIV_MIN		(2 << STM32H7_SPI_CFG1_MBR_MIN)
 150#define STM32H7_SPI_MBR_DIV_MAX		(2 << STM32H7_SPI_CFG1_MBR_MAX)
 151
 152/* STM32H7 SPI Communication mode */
 153#define STM32H7_SPI_FULL_DUPLEX		0
 154#define STM32H7_SPI_SIMPLEX_TX		1
 155#define STM32H7_SPI_SIMPLEX_RX		2
 156#define STM32H7_SPI_HALF_DUPLEX		3
 157
 158/* SPI Communication type */
 159#define SPI_FULL_DUPLEX		0
 160#define SPI_SIMPLEX_TX		1
 161#define SPI_SIMPLEX_RX		2
 162#define SPI_3WIRE_TX		3
 163#define SPI_3WIRE_RX		4
 164
 165#define STM32_SPI_AUTOSUSPEND_DELAY		1	/* 1 ms */
 166
 167/*
 168 * use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers
 169 * without fifo buffers.
 170 */
 171#define SPI_DMA_MIN_BYTES	16
 172
 173/**
 174 * struct stm32_spi_reg - stm32 SPI register & bitfield desc
 175 * @reg:		register offset
 176 * @mask:		bitfield mask
 177 * @shift:		left shift
 178 */
 179struct stm32_spi_reg {
 180	int reg;
 181	int mask;
 182	int shift;
 183};
 184
 185/**
 186 * struct stm32_spi_regspec - stm32 registers definition, compatible dependent data
 187 * @en: enable register and SPI enable bit
 188 * @dma_rx_en: SPI DMA RX enable register end SPI DMA RX enable bit
 189 * @dma_tx_en: SPI DMA TX enable register end SPI DMA TX enable bit
 190 * @cpol: clock polarity register and polarity bit
 191 * @cpha: clock phase register and phase bit
 192 * @lsb_first: LSB transmitted first register and bit
 193 * @br: baud rate register and bitfields
 194 * @rx: SPI RX data register
 195 * @tx: SPI TX data register
 196 */
 197struct stm32_spi_regspec {
 198	const struct stm32_spi_reg en;
 199	const struct stm32_spi_reg dma_rx_en;
 200	const struct stm32_spi_reg dma_tx_en;
 201	const struct stm32_spi_reg cpol;
 202	const struct stm32_spi_reg cpha;
 203	const struct stm32_spi_reg lsb_first;
 204	const struct stm32_spi_reg br;
 205	const struct stm32_spi_reg rx;
 206	const struct stm32_spi_reg tx;
 207};
 208
 209struct stm32_spi;
 210
 211/**
 212 * struct stm32_spi_cfg - stm32 compatible configuration data
 213 * @regs: registers descriptions
 214 * @get_fifo_size: routine to get fifo size
 215 * @get_bpw_mask: routine to get bits per word mask
 216 * @disable: routine to disable controller
 217 * @config: routine to configure controller as SPI Master
 218 * @set_bpw: routine to configure registers to for bits per word
 219 * @set_mode: routine to configure registers to desired mode
 220 * @set_data_idleness: optional routine to configure registers to desired idle
 221 * time between frames (if driver has this functionality)
 222 * @set_number_of_data: optional routine to configure registers to desired
 223 * number of data (if driver has this functionality)
 
 224 * @transfer_one_dma_start: routine to start transfer a single spi_transfer
 225 * using DMA
 226 * @dma_rx_cb: routine to call after DMA RX channel operation is complete
 227 * @dma_tx_cb: routine to call after DMA TX channel operation is complete
 228 * @transfer_one_irq: routine to configure interrupts for driver
 229 * @irq_handler_event: Interrupt handler for SPI controller events
 230 * @irq_handler_thread: thread of interrupt handler for SPI controller
 231 * @baud_rate_div_min: minimum baud rate divisor
 232 * @baud_rate_div_max: maximum baud rate divisor
 233 * @has_fifo: boolean to know if fifo is used for driver
 234 * @flags: compatible specific SPI controller flags used at registration time
 235 */
 236struct stm32_spi_cfg {
 237	const struct stm32_spi_regspec *regs;
 238	int (*get_fifo_size)(struct stm32_spi *spi);
 239	int (*get_bpw_mask)(struct stm32_spi *spi);
 240	void (*disable)(struct stm32_spi *spi);
 241	int (*config)(struct stm32_spi *spi);
 242	void (*set_bpw)(struct stm32_spi *spi);
 243	int (*set_mode)(struct stm32_spi *spi, unsigned int comm_type);
 244	void (*set_data_idleness)(struct stm32_spi *spi, u32 length);
 245	int (*set_number_of_data)(struct stm32_spi *spi, u32 length);
 246	void (*transfer_one_dma_start)(struct stm32_spi *spi);
 247	void (*dma_rx_cb)(void *data);
 248	void (*dma_tx_cb)(void *data);
 249	int (*transfer_one_irq)(struct stm32_spi *spi);
 250	irqreturn_t (*irq_handler_event)(int irq, void *dev_id);
 251	irqreturn_t (*irq_handler_thread)(int irq, void *dev_id);
 252	unsigned int baud_rate_div_min;
 253	unsigned int baud_rate_div_max;
 254	bool has_fifo;
 255	u16 flags;
 256};
 257
 258/**
 259 * struct stm32_spi - private data of the SPI controller
 260 * @dev: driver model representation of the controller
 261 * @master: controller master interface
 262 * @cfg: compatible configuration data
 263 * @base: virtual memory area
 264 * @clk: hw kernel clock feeding the SPI clock generator
 265 * @clk_rate: rate of the hw kernel clock feeding the SPI clock generator
 266 * @lock: prevent I/O concurrent access
 267 * @irq: SPI controller interrupt line
 268 * @fifo_size: size of the embedded fifo in bytes
 269 * @cur_midi: master inter-data idleness in ns
 270 * @cur_speed: speed configured in Hz
 271 * @cur_bpw: number of bits in a single SPI data frame
 272 * @cur_fthlv: fifo threshold level (data frames in a single data packet)
 273 * @cur_comm: SPI communication mode
 274 * @cur_xferlen: current transfer length in bytes
 275 * @cur_usedma: boolean to know if dma is used in current transfer
 276 * @tx_buf: data to be written, or NULL
 277 * @rx_buf: data to be read, or NULL
 278 * @tx_len: number of data to be written in bytes
 279 * @rx_len: number of data to be read in bytes
 280 * @dma_tx: dma channel for TX transfer
 281 * @dma_rx: dma channel for RX transfer
 282 * @phys_addr: SPI registers physical base address
 283 */
 284struct stm32_spi {
 285	struct device *dev;
 286	struct spi_master *master;
 287	const struct stm32_spi_cfg *cfg;
 288	void __iomem *base;
 289	struct clk *clk;
 290	u32 clk_rate;
 291	spinlock_t lock; /* prevent I/O concurrent access */
 292	int irq;
 293	unsigned int fifo_size;
 294
 295	unsigned int cur_midi;
 296	unsigned int cur_speed;
 297	unsigned int cur_bpw;
 298	unsigned int cur_fthlv;
 299	unsigned int cur_comm;
 300	unsigned int cur_xferlen;
 301	bool cur_usedma;
 302
 303	const void *tx_buf;
 304	void *rx_buf;
 305	int tx_len;
 306	int rx_len;
 307	struct dma_chan *dma_tx;
 308	struct dma_chan *dma_rx;
 309	dma_addr_t phys_addr;
 310};
 311
 312static const struct stm32_spi_regspec stm32f4_spi_regspec = {
 313	.en = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE },
 314
 315	.dma_rx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_RXDMAEN },
 316	.dma_tx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN },
 317
 318	.cpol = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPOL },
 319	.cpha = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPHA },
 320	.lsb_first = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_LSBFRST },
 321	.br = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_BR, STM32F4_SPI_CR1_BR_SHIFT },
 322
 323	.rx = { STM32F4_SPI_DR },
 324	.tx = { STM32F4_SPI_DR },
 325};
 326
 327static const struct stm32_spi_regspec stm32h7_spi_regspec = {
 328	/* SPI data transfer is enabled but spi_ker_ck is idle.
 329	 * CFG1 and CFG2 registers are write protected when SPE is enabled.
 330	 */
 331	.en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
 332
 333	.dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
 334	.dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
 335
 336	.cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
 337	.cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
 338	.lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
 339	.br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
 340		STM32H7_SPI_CFG1_MBR_SHIFT },
 341
 342	.rx = { STM32H7_SPI_RXDR },
 343	.tx = { STM32H7_SPI_TXDR },
 344};
 345
 346static inline void stm32_spi_set_bits(struct stm32_spi *spi,
 347				      u32 offset, u32 bits)
 348{
 349	writel_relaxed(readl_relaxed(spi->base + offset) | bits,
 350		       spi->base + offset);
 351}
 352
 353static inline void stm32_spi_clr_bits(struct stm32_spi *spi,
 354				      u32 offset, u32 bits)
 355{
 356	writel_relaxed(readl_relaxed(spi->base + offset) & ~bits,
 357		       spi->base + offset);
 358}
 359
 360/**
 361 * stm32h7_spi_get_fifo_size - Return fifo size
 362 * @spi: pointer to the spi controller data structure
 363 */
 364static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi)
 365{
 366	unsigned long flags;
 367	u32 count = 0;
 368
 369	spin_lock_irqsave(&spi->lock, flags);
 370
 371	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
 372
 373	while (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP)
 374		writeb_relaxed(++count, spi->base + STM32H7_SPI_TXDR);
 375
 376	stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
 377
 378	spin_unlock_irqrestore(&spi->lock, flags);
 379
 380	dev_dbg(spi->dev, "%d x 8-bit fifo size\n", count);
 381
 382	return count;
 383}
 384
 385/**
 386 * stm32f4_spi_get_bpw_mask - Return bits per word mask
 387 * @spi: pointer to the spi controller data structure
 388 */
 389static int stm32f4_spi_get_bpw_mask(struct stm32_spi *spi)
 390{
 391	dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
 392	return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
 393}
 394
 395/**
 396 * stm32h7_spi_get_bpw_mask - Return bits per word mask
 397 * @spi: pointer to the spi controller data structure
 398 */
 399static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi)
 400{
 401	unsigned long flags;
 402	u32 cfg1, max_bpw;
 403
 404	spin_lock_irqsave(&spi->lock, flags);
 405
 406	/*
 407	 * The most significant bit at DSIZE bit field is reserved when the
 408	 * maximum data size of periperal instances is limited to 16-bit
 409	 */
 410	stm32_spi_set_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_DSIZE);
 411
 412	cfg1 = readl_relaxed(spi->base + STM32H7_SPI_CFG1);
 413	max_bpw = FIELD_GET(STM32H7_SPI_CFG1_DSIZE, cfg1) + 1;
 414
 415	spin_unlock_irqrestore(&spi->lock, flags);
 416
 417	dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw);
 418
 419	return SPI_BPW_RANGE_MASK(4, max_bpw);
 420}
 421
 422/**
 423 * stm32_spi_prepare_mbr - Determine baud rate divisor value
 424 * @spi: pointer to the spi controller data structure
 425 * @speed_hz: requested speed
 426 * @min_div: minimum baud rate divisor
 427 * @max_div: maximum baud rate divisor
 428 *
 429 * Return baud rate divisor value in case of success or -EINVAL
 430 */
 431static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
 432				 u32 min_div, u32 max_div)
 433{
 434	u32 div, mbrdiv;
 435
 436	/* Ensure spi->clk_rate is even */
 437	div = DIV_ROUND_CLOSEST(spi->clk_rate & ~0x1, speed_hz);
 438
 439	/*
 440	 * SPI framework set xfer->speed_hz to master->max_speed_hz if
 441	 * xfer->speed_hz is greater than master->max_speed_hz, and it returns
 442	 * an error when xfer->speed_hz is lower than master->min_speed_hz, so
 443	 * no need to check it there.
 444	 * However, we need to ensure the following calculations.
 445	 */
 446	if ((div < min_div) || (div > max_div))
 447		return -EINVAL;
 448
 449	/* Determine the first power of 2 greater than or equal to div */
 450	if (div & (div - 1))
 451		mbrdiv = fls(div);
 452	else
 453		mbrdiv = fls(div) - 1;
 454
 455	spi->cur_speed = spi->clk_rate / (1 << mbrdiv);
 456
 457	return mbrdiv - 1;
 458}
 459
 460/**
 461 * stm32h7_spi_prepare_fthlv - Determine FIFO threshold level
 462 * @spi: pointer to the spi controller data structure
 463 * @xfer_len: length of the message to be transferred
 464 */
 465static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len)
 466{
 467	u32 packet, bpw;
 468
 469	/* data packet should not exceed 1/2 of fifo space */
 470	packet = clamp(xfer_len, 1U, spi->fifo_size / 2);
 471
 472	/* align packet size with data registers access */
 473	bpw = DIV_ROUND_UP(spi->cur_bpw, 8);
 474	return DIV_ROUND_UP(packet, bpw);
 475}
 476
 477/**
 478 * stm32f4_spi_write_tx - Write bytes to Transmit Data Register
 479 * @spi: pointer to the spi controller data structure
 480 *
 481 * Read from tx_buf depends on remaining bytes to avoid to read beyond
 482 * tx_buf end.
 483 */
 484static void stm32f4_spi_write_tx(struct stm32_spi *spi)
 485{
 486	if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) &
 487				  STM32F4_SPI_SR_TXE)) {
 488		u32 offs = spi->cur_xferlen - spi->tx_len;
 489
 490		if (spi->cur_bpw == 16) {
 491			const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
 492
 493			writew_relaxed(*tx_buf16, spi->base + STM32F4_SPI_DR);
 494			spi->tx_len -= sizeof(u16);
 495		} else {
 496			const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
 497
 498			writeb_relaxed(*tx_buf8, spi->base + STM32F4_SPI_DR);
 499			spi->tx_len -= sizeof(u8);
 500		}
 501	}
 502
 503	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
 504}
 505
 506/**
 507 * stm32h7_spi_write_txfifo - Write bytes in Transmit Data Register
 508 * @spi: pointer to the spi controller data structure
 509 *
 510 * Read from tx_buf depends on remaining bytes to avoid to read beyond
 511 * tx_buf end.
 512 */
 513static void stm32h7_spi_write_txfifo(struct stm32_spi *spi)
 514{
 515	while ((spi->tx_len > 0) &&
 516		       (readl_relaxed(spi->base + STM32H7_SPI_SR) &
 517			STM32H7_SPI_SR_TXP)) {
 518		u32 offs = spi->cur_xferlen - spi->tx_len;
 519
 520		if (spi->tx_len >= sizeof(u32)) {
 521			const u32 *tx_buf32 = (const u32 *)(spi->tx_buf + offs);
 522
 523			writel_relaxed(*tx_buf32, spi->base + STM32H7_SPI_TXDR);
 524			spi->tx_len -= sizeof(u32);
 525		} else if (spi->tx_len >= sizeof(u16)) {
 526			const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
 527
 528			writew_relaxed(*tx_buf16, spi->base + STM32H7_SPI_TXDR);
 529			spi->tx_len -= sizeof(u16);
 530		} else {
 531			const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
 532
 533			writeb_relaxed(*tx_buf8, spi->base + STM32H7_SPI_TXDR);
 534			spi->tx_len -= sizeof(u8);
 535		}
 536	}
 537
 538	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
 539}
 540
 541/**
 542 * stm32f4_spi_read_rx - Read bytes from Receive Data Register
 543 * @spi: pointer to the spi controller data structure
 544 *
 545 * Write in rx_buf depends on remaining bytes to avoid to write beyond
 546 * rx_buf end.
 547 */
 548static void stm32f4_spi_read_rx(struct stm32_spi *spi)
 549{
 550	if ((spi->rx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) &
 551				  STM32F4_SPI_SR_RXNE)) {
 552		u32 offs = spi->cur_xferlen - spi->rx_len;
 553
 554		if (spi->cur_bpw == 16) {
 555			u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
 556
 557			*rx_buf16 = readw_relaxed(spi->base + STM32F4_SPI_DR);
 558			spi->rx_len -= sizeof(u16);
 559		} else {
 560			u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
 561
 562			*rx_buf8 = readb_relaxed(spi->base + STM32F4_SPI_DR);
 563			spi->rx_len -= sizeof(u8);
 564		}
 565	}
 566
 567	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->rx_len);
 568}
 569
 570/**
 571 * stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register
 572 * @spi: pointer to the spi controller data structure
 
 573 *
 574 * Write in rx_buf depends on remaining bytes to avoid to write beyond
 575 * rx_buf end.
 576 */
 577static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi)
 578{
 579	u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
 580	u32 rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
 581
 582	while ((spi->rx_len > 0) &&
 583	       ((sr & STM32H7_SPI_SR_RXP) ||
 584		((sr & STM32H7_SPI_SR_EOT) &&
 585		 ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) {
 586		u32 offs = spi->cur_xferlen - spi->rx_len;
 587
 588		if ((spi->rx_len >= sizeof(u32)) ||
 589		    (sr & STM32H7_SPI_SR_RXWNE)) {
 590			u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs);
 591
 592			*rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR);
 593			spi->rx_len -= sizeof(u32);
 594		} else if ((spi->rx_len >= sizeof(u16)) ||
 595			   (!(sr & STM32H7_SPI_SR_RXWNE) &&
 596			    (rxplvl >= 2 || spi->cur_bpw > 8))) {
 597			u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
 598
 599			*rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR);
 600			spi->rx_len -= sizeof(u16);
 601		} else {
 602			u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
 603
 604			*rx_buf8 = readb_relaxed(spi->base + STM32H7_SPI_RXDR);
 605			spi->rx_len -= sizeof(u8);
 606		}
 607
 608		sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
 609		rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
 610	}
 611
 612	dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n",
 613		__func__, spi->rx_len, sr);
 614}
 615
 616/**
 617 * stm32_spi_enable - Enable SPI controller
 618 * @spi: pointer to the spi controller data structure
 619 */
 620static void stm32_spi_enable(struct stm32_spi *spi)
 621{
 622	dev_dbg(spi->dev, "enable controller\n");
 623
 624	stm32_spi_set_bits(spi, spi->cfg->regs->en.reg,
 625			   spi->cfg->regs->en.mask);
 626}
 627
 628/**
 629 * stm32f4_spi_disable - Disable SPI controller
 630 * @spi: pointer to the spi controller data structure
 631 */
 632static void stm32f4_spi_disable(struct stm32_spi *spi)
 633{
 634	unsigned long flags;
 635	u32 sr;
 636
 637	dev_dbg(spi->dev, "disable controller\n");
 638
 639	spin_lock_irqsave(&spi->lock, flags);
 640
 641	if (!(readl_relaxed(spi->base + STM32F4_SPI_CR1) &
 642	      STM32F4_SPI_CR1_SPE)) {
 643		spin_unlock_irqrestore(&spi->lock, flags);
 644		return;
 645	}
 646
 647	/* Disable interrupts */
 648	stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXEIE |
 649						 STM32F4_SPI_CR2_RXNEIE |
 650						 STM32F4_SPI_CR2_ERRIE);
 651
 652	/* Wait until BSY = 0 */
 653	if (readl_relaxed_poll_timeout_atomic(spi->base + STM32F4_SPI_SR,
 654					      sr, !(sr & STM32F4_SPI_SR_BSY),
 655					      10, 100000) < 0) {
 656		dev_warn(spi->dev, "disabling condition timeout\n");
 657	}
 658
 659	if (spi->cur_usedma && spi->dma_tx)
 660		dmaengine_terminate_all(spi->dma_tx);
 661	if (spi->cur_usedma && spi->dma_rx)
 662		dmaengine_terminate_all(spi->dma_rx);
 663
 664	stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE);
 665
 666	stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN |
 667						 STM32F4_SPI_CR2_RXDMAEN);
 668
 669	/* Sequence to clear OVR flag */
 670	readl_relaxed(spi->base + STM32F4_SPI_DR);
 671	readl_relaxed(spi->base + STM32F4_SPI_SR);
 672
 673	spin_unlock_irqrestore(&spi->lock, flags);
 674}
 675
 676/**
 677 * stm32h7_spi_disable - Disable SPI controller
 678 * @spi: pointer to the spi controller data structure
 679 *
 680 * RX-Fifo is flushed when SPI controller is disabled.
 
 
 
 
 
 
 681 */
 682static void stm32h7_spi_disable(struct stm32_spi *spi)
 683{
 684	unsigned long flags;
 685	u32 cr1;
 686
 687	dev_dbg(spi->dev, "disable controller\n");
 688
 689	spin_lock_irqsave(&spi->lock, flags);
 690
 691	cr1 = readl_relaxed(spi->base + STM32H7_SPI_CR1);
 692
 693	if (!(cr1 & STM32H7_SPI_CR1_SPE)) {
 694		spin_unlock_irqrestore(&spi->lock, flags);
 695		return;
 696	}
 697
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 698	if (spi->cur_usedma && spi->dma_tx)
 699		dmaengine_terminate_all(spi->dma_tx);
 700	if (spi->cur_usedma && spi->dma_rx)
 701		dmaengine_terminate_all(spi->dma_rx);
 702
 703	stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
 704
 705	stm32_spi_clr_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN |
 706						STM32H7_SPI_CFG1_RXDMAEN);
 707
 708	/* Disable interrupts and clear status flags */
 709	writel_relaxed(0, spi->base + STM32H7_SPI_IER);
 710	writel_relaxed(STM32H7_SPI_IFCR_ALL, spi->base + STM32H7_SPI_IFCR);
 711
 712	spin_unlock_irqrestore(&spi->lock, flags);
 713}
 714
 715/**
 716 * stm32_spi_can_dma - Determine if the transfer is eligible for DMA use
 717 * @master: controller master interface
 718 * @spi_dev: pointer to the spi device
 719 * @transfer: pointer to spi transfer
 720 *
 721 * If driver has fifo and the current transfer size is greater than fifo size,
 722 * use DMA. Otherwise use DMA for transfer longer than defined DMA min bytes.
 723 */
 724static bool stm32_spi_can_dma(struct spi_master *master,
 725			      struct spi_device *spi_dev,
 726			      struct spi_transfer *transfer)
 727{
 728	unsigned int dma_size;
 729	struct stm32_spi *spi = spi_master_get_devdata(master);
 730
 731	if (spi->cfg->has_fifo)
 732		dma_size = spi->fifo_size;
 733	else
 734		dma_size = SPI_DMA_MIN_BYTES;
 735
 736	dev_dbg(spi->dev, "%s: %s\n", __func__,
 737		(transfer->len > dma_size) ? "true" : "false");
 738
 739	return (transfer->len > dma_size);
 740}
 741
 742/**
 743 * stm32f4_spi_irq_event - Interrupt handler for SPI controller events
 744 * @irq: interrupt line
 745 * @dev_id: SPI controller master interface
 746 */
 747static irqreturn_t stm32f4_spi_irq_event(int irq, void *dev_id)
 748{
 749	struct spi_master *master = dev_id;
 750	struct stm32_spi *spi = spi_master_get_devdata(master);
 751	u32 sr, mask = 0;
 752	bool end = false;
 753
 754	spin_lock(&spi->lock);
 755
 756	sr = readl_relaxed(spi->base + STM32F4_SPI_SR);
 757	/*
 758	 * BSY flag is not handled in interrupt but it is normal behavior when
 759	 * this flag is set.
 760	 */
 761	sr &= ~STM32F4_SPI_SR_BSY;
 762
 763	if (!spi->cur_usedma && (spi->cur_comm == SPI_SIMPLEX_TX ||
 764				 spi->cur_comm == SPI_3WIRE_TX)) {
 765		/* OVR flag shouldn't be handled for TX only mode */
 766		sr &= ~(STM32F4_SPI_SR_OVR | STM32F4_SPI_SR_RXNE);
 767		mask |= STM32F4_SPI_SR_TXE;
 768	}
 769
 770	if (!spi->cur_usedma && (spi->cur_comm == SPI_FULL_DUPLEX ||
 771				spi->cur_comm == SPI_SIMPLEX_RX ||
 772				spi->cur_comm == SPI_3WIRE_RX)) {
 773		/* TXE flag is set and is handled when RXNE flag occurs */
 774		sr &= ~STM32F4_SPI_SR_TXE;
 775		mask |= STM32F4_SPI_SR_RXNE | STM32F4_SPI_SR_OVR;
 776	}
 777
 778	if (!(sr & mask)) {
 779		dev_dbg(spi->dev, "spurious IT (sr=0x%08x)\n", sr);
 780		spin_unlock(&spi->lock);
 781		return IRQ_NONE;
 782	}
 783
 784	if (sr & STM32F4_SPI_SR_OVR) {
 785		dev_warn(spi->dev, "Overrun: received value discarded\n");
 786
 787		/* Sequence to clear OVR flag */
 788		readl_relaxed(spi->base + STM32F4_SPI_DR);
 789		readl_relaxed(spi->base + STM32F4_SPI_SR);
 790
 791		/*
 792		 * If overrun is detected, it means that something went wrong,
 793		 * so stop the current transfer. Transfer can wait for next
 794		 * RXNE but DR is already read and end never happens.
 795		 */
 796		end = true;
 797		goto end_irq;
 798	}
 799
 800	if (sr & STM32F4_SPI_SR_TXE) {
 801		if (spi->tx_buf)
 802			stm32f4_spi_write_tx(spi);
 803		if (spi->tx_len == 0)
 804			end = true;
 805	}
 806
 807	if (sr & STM32F4_SPI_SR_RXNE) {
 808		stm32f4_spi_read_rx(spi);
 809		if (spi->rx_len == 0)
 810			end = true;
 811		else if (spi->tx_buf)/* Load data for discontinuous mode */
 812			stm32f4_spi_write_tx(spi);
 813	}
 814
 815end_irq:
 816	if (end) {
 817		/* Immediately disable interrupts to do not generate new one */
 818		stm32_spi_clr_bits(spi, STM32F4_SPI_CR2,
 819					STM32F4_SPI_CR2_TXEIE |
 820					STM32F4_SPI_CR2_RXNEIE |
 821					STM32F4_SPI_CR2_ERRIE);
 822		spin_unlock(&spi->lock);
 823		return IRQ_WAKE_THREAD;
 824	}
 825
 826	spin_unlock(&spi->lock);
 827	return IRQ_HANDLED;
 828}
 829
 830/**
 831 * stm32f4_spi_irq_thread - Thread of interrupt handler for SPI controller
 832 * @irq: interrupt line
 833 * @dev_id: SPI controller master interface
 834 */
 835static irqreturn_t stm32f4_spi_irq_thread(int irq, void *dev_id)
 836{
 837	struct spi_master *master = dev_id;
 838	struct stm32_spi *spi = spi_master_get_devdata(master);
 839
 840	spi_finalize_current_transfer(master);
 841	stm32f4_spi_disable(spi);
 842
 843	return IRQ_HANDLED;
 844}
 845
 846/**
 847 * stm32h7_spi_irq_thread - Thread of interrupt handler for SPI controller
 848 * @irq: interrupt line
 849 * @dev_id: SPI controller master interface
 850 */
 851static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
 852{
 853	struct spi_master *master = dev_id;
 854	struct stm32_spi *spi = spi_master_get_devdata(master);
 855	u32 sr, ier, mask;
 856	unsigned long flags;
 857	bool end = false;
 858
 859	spin_lock_irqsave(&spi->lock, flags);
 860
 861	sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
 862	ier = readl_relaxed(spi->base + STM32H7_SPI_IER);
 863
 864	mask = ier;
 865	/*
 866	 * EOTIE enables irq from EOT, SUSP and TXC events. We need to set
 867	 * SUSP to acknowledge it later. TXC is automatically cleared
 868	 */
 869
 870	mask |= STM32H7_SPI_SR_SUSP;
 871	/*
 872	 * DXPIE is set in Full-Duplex, one IT will be raised if TXP and RXP
 873	 * are set. So in case of Full-Duplex, need to poll TXP and RXP event.
 874	 */
 875	if ((spi->cur_comm == SPI_FULL_DUPLEX) && !spi->cur_usedma)
 876		mask |= STM32H7_SPI_SR_TXP | STM32H7_SPI_SR_RXP;
 877
 878	if (!(sr & mask)) {
 879		dev_warn(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
 880			 sr, ier);
 881		spin_unlock_irqrestore(&spi->lock, flags);
 882		return IRQ_NONE;
 883	}
 884
 885	if (sr & STM32H7_SPI_SR_SUSP) {
 886		static DEFINE_RATELIMIT_STATE(rs,
 887					      DEFAULT_RATELIMIT_INTERVAL * 10,
 888					      1);
 889		ratelimit_set_flags(&rs, RATELIMIT_MSG_ON_RELEASE);
 890		if (__ratelimit(&rs))
 891			dev_dbg_ratelimited(spi->dev, "Communication suspended\n");
 892		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
 893			stm32h7_spi_read_rxfifo(spi);
 894		/*
 895		 * If communication is suspended while using DMA, it means
 896		 * that something went wrong, so stop the current transfer
 897		 */
 898		if (spi->cur_usedma)
 899			end = true;
 900	}
 901
 902	if (sr & STM32H7_SPI_SR_MODF) {
 903		dev_warn(spi->dev, "Mode fault: transfer aborted\n");
 904		end = true;
 905	}
 906
 907	if (sr & STM32H7_SPI_SR_OVR) {
 908		dev_err(spi->dev, "Overrun: RX data lost\n");
 909		end = true;
 910	}
 911
 912	if (sr & STM32H7_SPI_SR_EOT) {
 913		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
 914			stm32h7_spi_read_rxfifo(spi);
 915		if (!spi->cur_usedma ||
 916		    (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX))
 917			end = true;
 918	}
 919
 920	if (sr & STM32H7_SPI_SR_TXP)
 921		if (!spi->cur_usedma && (spi->tx_buf && (spi->tx_len > 0)))
 922			stm32h7_spi_write_txfifo(spi);
 923
 924	if (sr & STM32H7_SPI_SR_RXP)
 925		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
 926			stm32h7_spi_read_rxfifo(spi);
 927
 928	writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR);
 929
 930	spin_unlock_irqrestore(&spi->lock, flags);
 931
 932	if (end) {
 933		stm32h7_spi_disable(spi);
 934		spi_finalize_current_transfer(master);
 935	}
 936
 937	return IRQ_HANDLED;
 938}
 939
 940/**
 941 * stm32_spi_prepare_msg - set up the controller to transfer a single message
 942 * @master: controller master interface
 943 * @msg: pointer to spi message
 944 */
 945static int stm32_spi_prepare_msg(struct spi_master *master,
 946				 struct spi_message *msg)
 947{
 948	struct stm32_spi *spi = spi_master_get_devdata(master);
 949	struct spi_device *spi_dev = msg->spi;
 950	struct device_node *np = spi_dev->dev.of_node;
 951	unsigned long flags;
 952	u32 clrb = 0, setb = 0;
 953
 954	/* SPI slave device may need time between data frames */
 955	spi->cur_midi = 0;
 956	if (np && !of_property_read_u32(np, "st,spi-midi-ns", &spi->cur_midi))
 957		dev_dbg(spi->dev, "%dns inter-data idleness\n", spi->cur_midi);
 958
 959	if (spi_dev->mode & SPI_CPOL)
 960		setb |= spi->cfg->regs->cpol.mask;
 961	else
 962		clrb |= spi->cfg->regs->cpol.mask;
 963
 964	if (spi_dev->mode & SPI_CPHA)
 965		setb |= spi->cfg->regs->cpha.mask;
 966	else
 967		clrb |= spi->cfg->regs->cpha.mask;
 968
 969	if (spi_dev->mode & SPI_LSB_FIRST)
 970		setb |= spi->cfg->regs->lsb_first.mask;
 971	else
 972		clrb |= spi->cfg->regs->lsb_first.mask;
 973
 974	dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n",
 975		!!(spi_dev->mode & SPI_CPOL),
 976		!!(spi_dev->mode & SPI_CPHA),
 977		!!(spi_dev->mode & SPI_LSB_FIRST),
 978		!!(spi_dev->mode & SPI_CS_HIGH));
 979
 980	/* On STM32H7, messages should not exceed a maximum size setted
 981	 * afterward via the set_number_of_data function. In order to
 982	 * ensure that, split large messages into several messages
 983	 */
 984	if (spi->cfg->set_number_of_data) {
 985		int ret;
 986
 987		ret = spi_split_transfers_maxsize(master, msg,
 988						  STM32H7_SPI_TSIZE_MAX,
 989						  GFP_KERNEL | GFP_DMA);
 990		if (ret)
 991			return ret;
 992	}
 993
 994	spin_lock_irqsave(&spi->lock, flags);
 995
 996	/* CPOL, CPHA and LSB FIRST bits have common register */
 997	if (clrb || setb)
 998		writel_relaxed(
 999			(readl_relaxed(spi->base + spi->cfg->regs->cpol.reg) &
1000			 ~clrb) | setb,
1001			spi->base + spi->cfg->regs->cpol.reg);
1002
1003	spin_unlock_irqrestore(&spi->lock, flags);
1004
1005	return 0;
1006}
1007
1008/**
1009 * stm32f4_spi_dma_tx_cb - dma callback
1010 * @data: pointer to the spi controller data structure
1011 *
1012 * DMA callback is called when the transfer is complete for DMA TX channel.
1013 */
1014static void stm32f4_spi_dma_tx_cb(void *data)
1015{
1016	struct stm32_spi *spi = data;
1017
1018	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
1019		spi_finalize_current_transfer(spi->master);
1020		stm32f4_spi_disable(spi);
1021	}
1022}
1023
1024/**
1025 * stm32_spi_dma_rx_cb - dma callback
1026 * @data: pointer to the spi controller data structure
1027 *
1028 * DMA callback is called when the transfer is complete for DMA RX channel.
1029 */
1030static void stm32_spi_dma_rx_cb(void *data)
1031{
1032	struct stm32_spi *spi = data;
1033
1034	spi_finalize_current_transfer(spi->master);
1035	spi->cfg->disable(spi);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1036}
1037
1038/**
1039 * stm32_spi_dma_config - configure dma slave channel depending on current
1040 *			  transfer bits_per_word.
1041 * @spi: pointer to the spi controller data structure
1042 * @dma_conf: pointer to the dma_slave_config structure
1043 * @dir: direction of the dma transfer
1044 */
1045static void stm32_spi_dma_config(struct stm32_spi *spi,
1046				 struct dma_slave_config *dma_conf,
1047				 enum dma_transfer_direction dir)
1048{
1049	enum dma_slave_buswidth buswidth;
1050	u32 maxburst;
1051
1052	if (spi->cur_bpw <= 8)
1053		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
1054	else if (spi->cur_bpw <= 16)
1055		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
1056	else
1057		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
1058
1059	if (spi->cfg->has_fifo) {
1060		/* Valid for DMA Half or Full Fifo threshold */
1061		if (spi->cur_fthlv == 2)
1062			maxburst = 1;
1063		else
1064			maxburst = spi->cur_fthlv;
1065	} else {
1066		maxburst = 1;
1067	}
1068
1069	memset(dma_conf, 0, sizeof(struct dma_slave_config));
1070	dma_conf->direction = dir;
1071	if (dma_conf->direction == DMA_DEV_TO_MEM) { /* RX */
1072		dma_conf->src_addr = spi->phys_addr + spi->cfg->regs->rx.reg;
1073		dma_conf->src_addr_width = buswidth;
1074		dma_conf->src_maxburst = maxburst;
1075
1076		dev_dbg(spi->dev, "Rx DMA config buswidth=%d, maxburst=%d\n",
1077			buswidth, maxburst);
1078	} else if (dma_conf->direction == DMA_MEM_TO_DEV) { /* TX */
1079		dma_conf->dst_addr = spi->phys_addr + spi->cfg->regs->tx.reg;
1080		dma_conf->dst_addr_width = buswidth;
1081		dma_conf->dst_maxburst = maxburst;
1082
1083		dev_dbg(spi->dev, "Tx DMA config buswidth=%d, maxburst=%d\n",
1084			buswidth, maxburst);
1085	}
1086}
1087
1088/**
1089 * stm32f4_spi_transfer_one_irq - transfer a single spi_transfer using
1090 *				  interrupts
1091 * @spi: pointer to the spi controller data structure
1092 *
1093 * It must returns 0 if the transfer is finished or 1 if the transfer is still
1094 * in progress.
1095 */
1096static int stm32f4_spi_transfer_one_irq(struct stm32_spi *spi)
1097{
1098	unsigned long flags;
1099	u32 cr2 = 0;
1100
1101	/* Enable the interrupts relative to the current communication mode */
1102	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
1103		cr2 |= STM32F4_SPI_CR2_TXEIE;
1104	} else if (spi->cur_comm == SPI_FULL_DUPLEX ||
1105				spi->cur_comm == SPI_SIMPLEX_RX ||
1106				spi->cur_comm == SPI_3WIRE_RX) {
1107		/* In transmit-only mode, the OVR flag is set in the SR register
1108		 * since the received data are never read. Therefore set OVR
1109		 * interrupt only when rx buffer is available.
1110		 */
1111		cr2 |= STM32F4_SPI_CR2_RXNEIE | STM32F4_SPI_CR2_ERRIE;
1112	} else {
1113		return -EINVAL;
1114	}
1115
1116	spin_lock_irqsave(&spi->lock, flags);
1117
1118	stm32_spi_set_bits(spi, STM32F4_SPI_CR2, cr2);
1119
1120	stm32_spi_enable(spi);
1121
1122	/* starting data transfer when buffer is loaded */
1123	if (spi->tx_buf)
1124		stm32f4_spi_write_tx(spi);
1125
1126	spin_unlock_irqrestore(&spi->lock, flags);
1127
1128	return 1;
1129}
1130
1131/**
1132 * stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using
1133 *				  interrupts
1134 * @spi: pointer to the spi controller data structure
1135 *
1136 * It must returns 0 if the transfer is finished or 1 if the transfer is still
1137 * in progress.
1138 */
1139static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi)
1140{
1141	unsigned long flags;
1142	u32 ier = 0;
1143
1144	/* Enable the interrupts relative to the current communication mode */
1145	if (spi->tx_buf && spi->rx_buf)	/* Full Duplex */
1146		ier |= STM32H7_SPI_IER_DXPIE;
1147	else if (spi->tx_buf)		/* Half-Duplex TX dir or Simplex TX */
1148		ier |= STM32H7_SPI_IER_TXPIE;
1149	else if (spi->rx_buf)		/* Half-Duplex RX dir or Simplex RX */
1150		ier |= STM32H7_SPI_IER_RXPIE;
1151
1152	/* Enable the interrupts relative to the end of transfer */
1153	ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE |
1154	       STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
1155
1156	spin_lock_irqsave(&spi->lock, flags);
1157
1158	stm32_spi_enable(spi);
1159
1160	/* Be sure to have data in fifo before starting data transfer */
1161	if (spi->tx_buf)
1162		stm32h7_spi_write_txfifo(spi);
1163
1164	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
1165
1166	writel_relaxed(ier, spi->base + STM32H7_SPI_IER);
1167
1168	spin_unlock_irqrestore(&spi->lock, flags);
1169
1170	return 1;
1171}
1172
1173/**
1174 * stm32f4_spi_transfer_one_dma_start - Set SPI driver registers to start
1175 *					transfer using DMA
1176 * @spi: pointer to the spi controller data structure
1177 */
1178static void stm32f4_spi_transfer_one_dma_start(struct stm32_spi *spi)
1179{
1180	/* In DMA mode end of transfer is handled by DMA TX or RX callback. */
1181	if (spi->cur_comm == SPI_SIMPLEX_RX || spi->cur_comm == SPI_3WIRE_RX ||
1182	    spi->cur_comm == SPI_FULL_DUPLEX) {
1183		/*
1184		 * In transmit-only mode, the OVR flag is set in the SR register
1185		 * since the received data are never read. Therefore set OVR
1186		 * interrupt only when rx buffer is available.
1187		 */
1188		stm32_spi_set_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_ERRIE);
1189	}
1190
1191	stm32_spi_enable(spi);
1192}
1193
1194/**
1195 * stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start
1196 *					transfer using DMA
1197 * @spi: pointer to the spi controller data structure
1198 */
1199static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
1200{
1201	uint32_t ier = STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
1202
1203	/* Enable the interrupts */
1204	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX)
1205		ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE;
1206
1207	stm32_spi_set_bits(spi, STM32H7_SPI_IER, ier);
1208
1209	stm32_spi_enable(spi);
1210
1211	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
1212}
1213
1214/**
1215 * stm32_spi_transfer_one_dma - transfer a single spi_transfer using DMA
1216 * @spi: pointer to the spi controller data structure
1217 * @xfer: pointer to the spi_transfer structure
1218 *
1219 * It must returns 0 if the transfer is finished or 1 if the transfer is still
1220 * in progress.
1221 */
1222static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
1223				      struct spi_transfer *xfer)
1224{
1225	struct dma_slave_config tx_dma_conf, rx_dma_conf;
1226	struct dma_async_tx_descriptor *tx_dma_desc, *rx_dma_desc;
1227	unsigned long flags;
1228
1229	spin_lock_irqsave(&spi->lock, flags);
1230
1231	rx_dma_desc = NULL;
1232	if (spi->rx_buf && spi->dma_rx) {
1233		stm32_spi_dma_config(spi, &rx_dma_conf, DMA_DEV_TO_MEM);
1234		dmaengine_slave_config(spi->dma_rx, &rx_dma_conf);
1235
1236		/* Enable Rx DMA request */
1237		stm32_spi_set_bits(spi, spi->cfg->regs->dma_rx_en.reg,
1238				   spi->cfg->regs->dma_rx_en.mask);
1239
1240		rx_dma_desc = dmaengine_prep_slave_sg(
1241					spi->dma_rx, xfer->rx_sg.sgl,
1242					xfer->rx_sg.nents,
1243					rx_dma_conf.direction,
1244					DMA_PREP_INTERRUPT);
1245	}
1246
1247	tx_dma_desc = NULL;
1248	if (spi->tx_buf && spi->dma_tx) {
1249		stm32_spi_dma_config(spi, &tx_dma_conf, DMA_MEM_TO_DEV);
1250		dmaengine_slave_config(spi->dma_tx, &tx_dma_conf);
1251
1252		tx_dma_desc = dmaengine_prep_slave_sg(
1253					spi->dma_tx, xfer->tx_sg.sgl,
1254					xfer->tx_sg.nents,
1255					tx_dma_conf.direction,
1256					DMA_PREP_INTERRUPT);
1257	}
1258
1259	if ((spi->tx_buf && spi->dma_tx && !tx_dma_desc) ||
1260	    (spi->rx_buf && spi->dma_rx && !rx_dma_desc))
1261		goto dma_desc_error;
1262
1263	if (spi->cur_comm == SPI_FULL_DUPLEX && (!tx_dma_desc || !rx_dma_desc))
1264		goto dma_desc_error;
1265
1266	if (rx_dma_desc) {
1267		rx_dma_desc->callback = spi->cfg->dma_rx_cb;
1268		rx_dma_desc->callback_param = spi;
1269
1270		if (dma_submit_error(dmaengine_submit(rx_dma_desc))) {
1271			dev_err(spi->dev, "Rx DMA submit failed\n");
1272			goto dma_desc_error;
1273		}
1274		/* Enable Rx DMA channel */
1275		dma_async_issue_pending(spi->dma_rx);
1276	}
1277
1278	if (tx_dma_desc) {
1279		if (spi->cur_comm == SPI_SIMPLEX_TX ||
1280		    spi->cur_comm == SPI_3WIRE_TX) {
1281			tx_dma_desc->callback = spi->cfg->dma_tx_cb;
1282			tx_dma_desc->callback_param = spi;
1283		}
1284
1285		if (dma_submit_error(dmaengine_submit(tx_dma_desc))) {
1286			dev_err(spi->dev, "Tx DMA submit failed\n");
1287			goto dma_submit_error;
1288		}
1289		/* Enable Tx DMA channel */
1290		dma_async_issue_pending(spi->dma_tx);
1291
1292		/* Enable Tx DMA request */
1293		stm32_spi_set_bits(spi, spi->cfg->regs->dma_tx_en.reg,
1294				   spi->cfg->regs->dma_tx_en.mask);
1295	}
1296
1297	spi->cfg->transfer_one_dma_start(spi);
1298
1299	spin_unlock_irqrestore(&spi->lock, flags);
1300
1301	return 1;
1302
1303dma_submit_error:
1304	if (spi->dma_rx)
1305		dmaengine_terminate_all(spi->dma_rx);
1306
1307dma_desc_error:
1308	stm32_spi_clr_bits(spi, spi->cfg->regs->dma_rx_en.reg,
1309			   spi->cfg->regs->dma_rx_en.mask);
1310
1311	spin_unlock_irqrestore(&spi->lock, flags);
1312
1313	dev_info(spi->dev, "DMA issue: fall back to irq transfer\n");
1314
1315	spi->cur_usedma = false;
1316	return spi->cfg->transfer_one_irq(spi);
1317}
1318
1319/**
1320 * stm32f4_spi_set_bpw - Configure bits per word
1321 * @spi: pointer to the spi controller data structure
1322 */
1323static void stm32f4_spi_set_bpw(struct stm32_spi *spi)
1324{
1325	if (spi->cur_bpw == 16)
1326		stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF);
1327	else
1328		stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF);
1329}
1330
1331/**
1332 * stm32h7_spi_set_bpw - configure bits per word
1333 * @spi: pointer to the spi controller data structure
1334 */
1335static void stm32h7_spi_set_bpw(struct stm32_spi *spi)
1336{
1337	u32 bpw, fthlv;
1338	u32 cfg1_clrb = 0, cfg1_setb = 0;
1339
1340	bpw = spi->cur_bpw - 1;
1341
1342	cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE;
1343	cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_DSIZE, bpw);
1344
1345	spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen);
1346	fthlv = spi->cur_fthlv - 1;
1347
1348	cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
1349	cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_FTHLV, fthlv);
1350
1351	writel_relaxed(
1352		(readl_relaxed(spi->base + STM32H7_SPI_CFG1) &
1353		 ~cfg1_clrb) | cfg1_setb,
1354		spi->base + STM32H7_SPI_CFG1);
1355}
1356
1357/**
1358 * stm32_spi_set_mbr - Configure baud rate divisor in master mode
1359 * @spi: pointer to the spi controller data structure
1360 * @mbrdiv: baud rate divisor value
1361 */
1362static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv)
1363{
1364	u32 clrb = 0, setb = 0;
1365
1366	clrb |= spi->cfg->regs->br.mask;
1367	setb |= (mbrdiv << spi->cfg->regs->br.shift) & spi->cfg->regs->br.mask;
1368
1369	writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) &
1370			~clrb) | setb,
1371		       spi->base + spi->cfg->regs->br.reg);
1372}
1373
1374/**
1375 * stm32_spi_communication_type - return transfer communication type
1376 * @spi_dev: pointer to the spi device
1377 * @transfer: pointer to spi transfer
1378 */
1379static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev,
1380						 struct spi_transfer *transfer)
1381{
1382	unsigned int type = SPI_FULL_DUPLEX;
1383
1384	if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */
1385		/*
1386		 * SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL
1387		 * is forbidden and unvalidated by SPI subsystem so depending
1388		 * on the valid buffer, we can determine the direction of the
1389		 * transfer.
1390		 */
1391		if (!transfer->tx_buf)
1392			type = SPI_3WIRE_RX;
1393		else
1394			type = SPI_3WIRE_TX;
1395	} else {
1396		if (!transfer->tx_buf)
1397			type = SPI_SIMPLEX_RX;
1398		else if (!transfer->rx_buf)
1399			type = SPI_SIMPLEX_TX;
1400	}
1401
1402	return type;
1403}
1404
1405/**
1406 * stm32f4_spi_set_mode - configure communication mode
1407 * @spi: pointer to the spi controller data structure
1408 * @comm_type: type of communication to configure
1409 */
1410static int stm32f4_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
1411{
1412	if (comm_type == SPI_3WIRE_TX || comm_type == SPI_SIMPLEX_TX) {
1413		stm32_spi_set_bits(spi, STM32F4_SPI_CR1,
1414					STM32F4_SPI_CR1_BIDIMODE |
1415					STM32F4_SPI_CR1_BIDIOE);
1416	} else if (comm_type == SPI_FULL_DUPLEX ||
1417				comm_type == SPI_SIMPLEX_RX) {
1418		stm32_spi_clr_bits(spi, STM32F4_SPI_CR1,
1419					STM32F4_SPI_CR1_BIDIMODE |
1420					STM32F4_SPI_CR1_BIDIOE);
1421	} else if (comm_type == SPI_3WIRE_RX) {
1422		stm32_spi_set_bits(spi, STM32F4_SPI_CR1,
1423					STM32F4_SPI_CR1_BIDIMODE);
1424		stm32_spi_clr_bits(spi, STM32F4_SPI_CR1,
1425					STM32F4_SPI_CR1_BIDIOE);
1426	} else {
1427		return -EINVAL;
1428	}
1429
1430	return 0;
1431}
1432
1433/**
1434 * stm32h7_spi_set_mode - configure communication mode
1435 * @spi: pointer to the spi controller data structure
1436 * @comm_type: type of communication to configure
1437 */
1438static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
1439{
1440	u32 mode;
1441	u32 cfg2_clrb = 0, cfg2_setb = 0;
1442
1443	if (comm_type == SPI_3WIRE_RX) {
1444		mode = STM32H7_SPI_HALF_DUPLEX;
1445		stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
1446	} else if (comm_type == SPI_3WIRE_TX) {
1447		mode = STM32H7_SPI_HALF_DUPLEX;
1448		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
1449	} else if (comm_type == SPI_SIMPLEX_RX) {
1450		mode = STM32H7_SPI_SIMPLEX_RX;
1451	} else if (comm_type == SPI_SIMPLEX_TX) {
1452		mode = STM32H7_SPI_SIMPLEX_TX;
1453	} else {
1454		mode = STM32H7_SPI_FULL_DUPLEX;
1455	}
1456
1457	cfg2_clrb |= STM32H7_SPI_CFG2_COMM;
1458	cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_COMM, mode);
1459
1460	writel_relaxed(
1461		(readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
1462		 ~cfg2_clrb) | cfg2_setb,
1463		spi->base + STM32H7_SPI_CFG2);
1464
1465	return 0;
1466}
1467
1468/**
1469 * stm32h7_spi_data_idleness - configure minimum time delay inserted between two
1470 *			       consecutive data frames in master mode
1471 * @spi: pointer to the spi controller data structure
1472 * @len: transfer len
1473 */
1474static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len)
1475{
1476	u32 cfg2_clrb = 0, cfg2_setb = 0;
1477
1478	cfg2_clrb |= STM32H7_SPI_CFG2_MIDI;
1479	if ((len > 1) && (spi->cur_midi > 0)) {
1480		u32 sck_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, spi->cur_speed);
1481		u32 midi = min_t(u32,
1482				 DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
1483				 FIELD_GET(STM32H7_SPI_CFG2_MIDI,
1484				 STM32H7_SPI_CFG2_MIDI));
1485
1486
1487		dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n",
1488			sck_period_ns, midi, midi * sck_period_ns);
1489		cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_MIDI, midi);
1490	}
1491
1492	writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
1493			~cfg2_clrb) | cfg2_setb,
1494		       spi->base + STM32H7_SPI_CFG2);
1495}
1496
1497/**
1498 * stm32h7_spi_number_of_data - configure number of data at current transfer
1499 * @spi: pointer to the spi controller data structure
1500 * @nb_words: transfer length (in words)
1501 */
1502static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words)
1503{
1504	if (nb_words <= STM32H7_SPI_TSIZE_MAX) {
1505		writel_relaxed(FIELD_PREP(STM32H7_SPI_CR2_TSIZE, nb_words),
1506			       spi->base + STM32H7_SPI_CR2);
1507	} else {
1508		return -EMSGSIZE;
1509	}
1510
1511	return 0;
1512}
1513
1514/**
1515 * stm32_spi_transfer_one_setup - common setup to transfer a single
1516 *				  spi_transfer either using DMA or
1517 *				  interrupts.
1518 * @spi: pointer to the spi controller data structure
1519 * @spi_dev: pointer to the spi device
1520 * @transfer: pointer to spi transfer
1521 */
1522static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
1523					struct spi_device *spi_dev,
1524					struct spi_transfer *transfer)
1525{
1526	unsigned long flags;
1527	unsigned int comm_type;
1528	int nb_words, ret = 0;
1529	int mbr;
1530
1531	spin_lock_irqsave(&spi->lock, flags);
1532
1533	spi->cur_xferlen = transfer->len;
1534
1535	spi->cur_bpw = transfer->bits_per_word;
1536	spi->cfg->set_bpw(spi);
1537
1538	/* Update spi->cur_speed with real clock speed */
1539	mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
1540				    spi->cfg->baud_rate_div_min,
1541				    spi->cfg->baud_rate_div_max);
1542	if (mbr < 0) {
1543		ret = mbr;
1544		goto out;
1545	}
1546
1547	transfer->speed_hz = spi->cur_speed;
1548	stm32_spi_set_mbr(spi, mbr);
1549
1550	comm_type = stm32_spi_communication_type(spi_dev, transfer);
1551	ret = spi->cfg->set_mode(spi, comm_type);
1552	if (ret < 0)
1553		goto out;
1554
1555	spi->cur_comm = comm_type;
1556
1557	if (spi->cfg->set_data_idleness)
1558		spi->cfg->set_data_idleness(spi, transfer->len);
1559
1560	if (spi->cur_bpw <= 8)
1561		nb_words = transfer->len;
1562	else if (spi->cur_bpw <= 16)
1563		nb_words = DIV_ROUND_UP(transfer->len * 8, 16);
1564	else
1565		nb_words = DIV_ROUND_UP(transfer->len * 8, 32);
1566
1567	if (spi->cfg->set_number_of_data) {
1568		ret = spi->cfg->set_number_of_data(spi, nb_words);
1569		if (ret < 0)
1570			goto out;
1571	}
1572
1573	dev_dbg(spi->dev, "transfer communication mode set to %d\n",
1574		spi->cur_comm);
1575	dev_dbg(spi->dev,
1576		"data frame of %d-bit, data packet of %d data frames\n",
1577		spi->cur_bpw, spi->cur_fthlv);
1578	dev_dbg(spi->dev, "speed set to %dHz\n", spi->cur_speed);
1579	dev_dbg(spi->dev, "transfer of %d bytes (%d data frames)\n",
1580		spi->cur_xferlen, nb_words);
1581	dev_dbg(spi->dev, "dma %s\n",
1582		(spi->cur_usedma) ? "enabled" : "disabled");
1583
1584out:
1585	spin_unlock_irqrestore(&spi->lock, flags);
1586
1587	return ret;
1588}
1589
1590/**
1591 * stm32_spi_transfer_one - transfer a single spi_transfer
1592 * @master: controller master interface
1593 * @spi_dev: pointer to the spi device
1594 * @transfer: pointer to spi transfer
1595 *
1596 * It must return 0 if the transfer is finished or 1 if the transfer is still
1597 * in progress.
1598 */
1599static int stm32_spi_transfer_one(struct spi_master *master,
1600				  struct spi_device *spi_dev,
1601				  struct spi_transfer *transfer)
1602{
1603	struct stm32_spi *spi = spi_master_get_devdata(master);
1604	int ret;
1605
 
 
 
 
1606	spi->tx_buf = transfer->tx_buf;
1607	spi->rx_buf = transfer->rx_buf;
1608	spi->tx_len = spi->tx_buf ? transfer->len : 0;
1609	spi->rx_len = spi->rx_buf ? transfer->len : 0;
1610
1611	spi->cur_usedma = (master->can_dma &&
1612			   master->can_dma(master, spi_dev, transfer));
1613
1614	ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer);
1615	if (ret) {
1616		dev_err(spi->dev, "SPI transfer setup failed\n");
1617		return ret;
1618	}
1619
1620	if (spi->cur_usedma)
1621		return stm32_spi_transfer_one_dma(spi, transfer);
1622	else
1623		return spi->cfg->transfer_one_irq(spi);
1624}
1625
1626/**
1627 * stm32_spi_unprepare_msg - relax the hardware
1628 * @master: controller master interface
1629 * @msg: pointer to the spi message
1630 */
1631static int stm32_spi_unprepare_msg(struct spi_master *master,
1632				   struct spi_message *msg)
1633{
1634	struct stm32_spi *spi = spi_master_get_devdata(master);
1635
1636	spi->cfg->disable(spi);
1637
1638	return 0;
1639}
1640
1641/**
1642 * stm32f4_spi_config - Configure SPI controller as SPI master
1643 * @spi: pointer to the spi controller data structure
1644 */
1645static int stm32f4_spi_config(struct stm32_spi *spi)
1646{
1647	unsigned long flags;
1648
1649	spin_lock_irqsave(&spi->lock, flags);
1650
1651	/* Ensure I2SMOD bit is kept cleared */
1652	stm32_spi_clr_bits(spi, STM32F4_SPI_I2SCFGR,
1653			   STM32F4_SPI_I2SCFGR_I2SMOD);
1654
1655	/*
1656	 * - SS input value high
1657	 * - transmitter half duplex direction
1658	 * - Set the master mode (default Motorola mode)
1659	 * - Consider 1 master/n slaves configuration and
1660	 *   SS input value is determined by the SSI bit
1661	 */
1662	stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SSI |
1663						 STM32F4_SPI_CR1_BIDIOE |
1664						 STM32F4_SPI_CR1_MSTR |
1665						 STM32F4_SPI_CR1_SSM);
1666
1667	spin_unlock_irqrestore(&spi->lock, flags);
1668
1669	return 0;
1670}
1671
1672/**
1673 * stm32h7_spi_config - Configure SPI controller as SPI master
1674 * @spi: pointer to the spi controller data structure
1675 */
1676static int stm32h7_spi_config(struct stm32_spi *spi)
1677{
1678	unsigned long flags;
1679
1680	spin_lock_irqsave(&spi->lock, flags);
1681
1682	/* Ensure I2SMOD bit is kept cleared */
1683	stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR,
1684			   STM32H7_SPI_I2SCFGR_I2SMOD);
1685
1686	/*
1687	 * - SS input value high
1688	 * - transmitter half duplex direction
1689	 * - automatic communication suspend when RX-Fifo is full
1690	 */
1691	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SSI |
1692						 STM32H7_SPI_CR1_HDDIR |
1693						 STM32H7_SPI_CR1_MASRX);
1694
1695	/*
1696	 * - Set the master mode (default Motorola mode)
1697	 * - Consider 1 master/n slaves configuration and
1698	 *   SS input value is determined by the SSI bit
1699	 * - keep control of all associated GPIOs
1700	 */
1701	stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_MASTER |
1702						  STM32H7_SPI_CFG2_SSM |
1703						  STM32H7_SPI_CFG2_AFCNTR);
1704
1705	spin_unlock_irqrestore(&spi->lock, flags);
1706
1707	return 0;
1708}
1709
1710static const struct stm32_spi_cfg stm32f4_spi_cfg = {
1711	.regs = &stm32f4_spi_regspec,
1712	.get_bpw_mask = stm32f4_spi_get_bpw_mask,
1713	.disable = stm32f4_spi_disable,
1714	.config = stm32f4_spi_config,
1715	.set_bpw = stm32f4_spi_set_bpw,
1716	.set_mode = stm32f4_spi_set_mode,
1717	.transfer_one_dma_start = stm32f4_spi_transfer_one_dma_start,
1718	.dma_tx_cb = stm32f4_spi_dma_tx_cb,
1719	.dma_rx_cb = stm32_spi_dma_rx_cb,
1720	.transfer_one_irq = stm32f4_spi_transfer_one_irq,
1721	.irq_handler_event = stm32f4_spi_irq_event,
1722	.irq_handler_thread = stm32f4_spi_irq_thread,
1723	.baud_rate_div_min = STM32F4_SPI_BR_DIV_MIN,
1724	.baud_rate_div_max = STM32F4_SPI_BR_DIV_MAX,
1725	.has_fifo = false,
1726	.flags = SPI_MASTER_MUST_TX,
1727};
1728
1729static const struct stm32_spi_cfg stm32h7_spi_cfg = {
1730	.regs = &stm32h7_spi_regspec,
1731	.get_fifo_size = stm32h7_spi_get_fifo_size,
1732	.get_bpw_mask = stm32h7_spi_get_bpw_mask,
1733	.disable = stm32h7_spi_disable,
1734	.config = stm32h7_spi_config,
1735	.set_bpw = stm32h7_spi_set_bpw,
1736	.set_mode = stm32h7_spi_set_mode,
1737	.set_data_idleness = stm32h7_spi_data_idleness,
1738	.set_number_of_data = stm32h7_spi_number_of_data,
1739	.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
1740	.dma_rx_cb = stm32_spi_dma_rx_cb,
1741	/*
1742	 * dma_tx_cb is not necessary since in case of TX, dma is followed by
1743	 * SPI access hence handling is performed within the SPI interrupt
1744	 */
1745	.transfer_one_irq = stm32h7_spi_transfer_one_irq,
1746	.irq_handler_thread = stm32h7_spi_irq_thread,
1747	.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
1748	.baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
1749	.has_fifo = true,
1750};
1751
1752static const struct of_device_id stm32_spi_of_match[] = {
1753	{ .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg },
1754	{ .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg },
1755	{},
1756};
1757MODULE_DEVICE_TABLE(of, stm32_spi_of_match);
1758
1759static int stm32_spi_probe(struct platform_device *pdev)
1760{
1761	struct spi_master *master;
1762	struct stm32_spi *spi;
1763	struct resource *res;
1764	struct reset_control *rst;
1765	int ret;
1766
1767	master = devm_spi_alloc_master(&pdev->dev, sizeof(struct stm32_spi));
1768	if (!master) {
1769		dev_err(&pdev->dev, "spi master allocation failed\n");
1770		return -ENOMEM;
1771	}
1772	platform_set_drvdata(pdev, master);
1773
1774	spi = spi_master_get_devdata(master);
1775	spi->dev = &pdev->dev;
1776	spi->master = master;
1777	spin_lock_init(&spi->lock);
1778
1779	spi->cfg = (const struct stm32_spi_cfg *)
1780		of_match_device(pdev->dev.driver->of_match_table,
1781				&pdev->dev)->data;
1782
1783	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1784	spi->base = devm_ioremap_resource(&pdev->dev, res);
1785	if (IS_ERR(spi->base))
1786		return PTR_ERR(spi->base);
1787
1788	spi->phys_addr = (dma_addr_t)res->start;
1789
1790	spi->irq = platform_get_irq(pdev, 0);
1791	if (spi->irq <= 0)
1792		return dev_err_probe(&pdev->dev, spi->irq,
1793				     "failed to get irq\n");
1794
1795	ret = devm_request_threaded_irq(&pdev->dev, spi->irq,
1796					spi->cfg->irq_handler_event,
1797					spi->cfg->irq_handler_thread,
1798					IRQF_ONESHOT, pdev->name, master);
1799	if (ret) {
1800		dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq,
1801			ret);
1802		return ret;
1803	}
1804
1805	spi->clk = devm_clk_get(&pdev->dev, NULL);
1806	if (IS_ERR(spi->clk)) {
1807		ret = PTR_ERR(spi->clk);
1808		dev_err(&pdev->dev, "clk get failed: %d\n", ret);
1809		return ret;
1810	}
1811
1812	ret = clk_prepare_enable(spi->clk);
1813	if (ret) {
1814		dev_err(&pdev->dev, "clk enable failed: %d\n", ret);
1815		return ret;
1816	}
1817	spi->clk_rate = clk_get_rate(spi->clk);
1818	if (!spi->clk_rate) {
1819		dev_err(&pdev->dev, "clk rate = 0\n");
1820		ret = -EINVAL;
1821		goto err_clk_disable;
1822	}
1823
1824	rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
1825	if (rst) {
1826		if (IS_ERR(rst)) {
1827			ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
1828					    "failed to get reset\n");
1829			goto err_clk_disable;
1830		}
1831
1832		reset_control_assert(rst);
1833		udelay(2);
1834		reset_control_deassert(rst);
1835	}
1836
1837	if (spi->cfg->has_fifo)
1838		spi->fifo_size = spi->cfg->get_fifo_size(spi);
1839
1840	ret = spi->cfg->config(spi);
1841	if (ret) {
1842		dev_err(&pdev->dev, "controller configuration failed: %d\n",
1843			ret);
1844		goto err_clk_disable;
1845	}
1846
1847	master->dev.of_node = pdev->dev.of_node;
1848	master->auto_runtime_pm = true;
1849	master->bus_num = pdev->id;
1850	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
1851			    SPI_3WIRE;
1852	master->bits_per_word_mask = spi->cfg->get_bpw_mask(spi);
1853	master->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min;
1854	master->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max;
1855	master->use_gpio_descriptors = true;
1856	master->prepare_message = stm32_spi_prepare_msg;
1857	master->transfer_one = stm32_spi_transfer_one;
1858	master->unprepare_message = stm32_spi_unprepare_msg;
1859	master->flags = spi->cfg->flags;
1860
1861	spi->dma_tx = dma_request_chan(spi->dev, "tx");
1862	if (IS_ERR(spi->dma_tx)) {
1863		ret = PTR_ERR(spi->dma_tx);
1864		spi->dma_tx = NULL;
1865		if (ret == -EPROBE_DEFER)
1866			goto err_clk_disable;
1867
1868		dev_warn(&pdev->dev, "failed to request tx dma channel\n");
1869	} else {
1870		master->dma_tx = spi->dma_tx;
1871	}
1872
1873	spi->dma_rx = dma_request_chan(spi->dev, "rx");
1874	if (IS_ERR(spi->dma_rx)) {
1875		ret = PTR_ERR(spi->dma_rx);
1876		spi->dma_rx = NULL;
1877		if (ret == -EPROBE_DEFER)
1878			goto err_dma_release;
1879
1880		dev_warn(&pdev->dev, "failed to request rx dma channel\n");
1881	} else {
1882		master->dma_rx = spi->dma_rx;
1883	}
1884
1885	if (spi->dma_tx || spi->dma_rx)
1886		master->can_dma = stm32_spi_can_dma;
1887
1888	pm_runtime_set_autosuspend_delay(&pdev->dev,
1889					 STM32_SPI_AUTOSUSPEND_DELAY);
1890	pm_runtime_use_autosuspend(&pdev->dev);
1891	pm_runtime_set_active(&pdev->dev);
1892	pm_runtime_get_noresume(&pdev->dev);
1893	pm_runtime_enable(&pdev->dev);
1894
1895	ret = spi_register_master(master);
1896	if (ret) {
1897		dev_err(&pdev->dev, "spi master registration failed: %d\n",
1898			ret);
1899		goto err_pm_disable;
1900	}
1901
1902	pm_runtime_mark_last_busy(&pdev->dev);
1903	pm_runtime_put_autosuspend(&pdev->dev);
1904
1905	dev_info(&pdev->dev, "driver initialized\n");
1906
1907	return 0;
1908
1909err_pm_disable:
1910	pm_runtime_disable(&pdev->dev);
1911	pm_runtime_put_noidle(&pdev->dev);
1912	pm_runtime_set_suspended(&pdev->dev);
1913	pm_runtime_dont_use_autosuspend(&pdev->dev);
1914err_dma_release:
1915	if (spi->dma_tx)
1916		dma_release_channel(spi->dma_tx);
1917	if (spi->dma_rx)
1918		dma_release_channel(spi->dma_rx);
1919err_clk_disable:
1920	clk_disable_unprepare(spi->clk);
1921
1922	return ret;
1923}
1924
1925static int stm32_spi_remove(struct platform_device *pdev)
1926{
1927	struct spi_master *master = platform_get_drvdata(pdev);
1928	struct stm32_spi *spi = spi_master_get_devdata(master);
1929
1930	pm_runtime_get_sync(&pdev->dev);
1931
1932	spi_unregister_master(master);
1933	spi->cfg->disable(spi);
1934
1935	pm_runtime_disable(&pdev->dev);
1936	pm_runtime_put_noidle(&pdev->dev);
1937	pm_runtime_set_suspended(&pdev->dev);
1938	pm_runtime_dont_use_autosuspend(&pdev->dev);
1939
1940	if (master->dma_tx)
1941		dma_release_channel(master->dma_tx);
1942	if (master->dma_rx)
1943		dma_release_channel(master->dma_rx);
1944
1945	clk_disable_unprepare(spi->clk);
1946
1947
1948	pinctrl_pm_select_sleep_state(&pdev->dev);
1949
1950	return 0;
1951}
1952
1953static int __maybe_unused stm32_spi_runtime_suspend(struct device *dev)
1954{
1955	struct spi_master *master = dev_get_drvdata(dev);
1956	struct stm32_spi *spi = spi_master_get_devdata(master);
1957
1958	clk_disable_unprepare(spi->clk);
1959
1960	return pinctrl_pm_select_sleep_state(dev);
1961}
1962
1963static int __maybe_unused stm32_spi_runtime_resume(struct device *dev)
1964{
1965	struct spi_master *master = dev_get_drvdata(dev);
1966	struct stm32_spi *spi = spi_master_get_devdata(master);
1967	int ret;
1968
1969	ret = pinctrl_pm_select_default_state(dev);
1970	if (ret)
1971		return ret;
1972
1973	return clk_prepare_enable(spi->clk);
1974}
1975
1976static int __maybe_unused stm32_spi_suspend(struct device *dev)
1977{
1978	struct spi_master *master = dev_get_drvdata(dev);
1979	int ret;
1980
1981	ret = spi_master_suspend(master);
1982	if (ret)
1983		return ret;
1984
1985	return pm_runtime_force_suspend(dev);
1986}
1987
1988static int __maybe_unused stm32_spi_resume(struct device *dev)
1989{
1990	struct spi_master *master = dev_get_drvdata(dev);
1991	struct stm32_spi *spi = spi_master_get_devdata(master);
1992	int ret;
1993
1994	ret = pm_runtime_force_resume(dev);
1995	if (ret)
1996		return ret;
1997
1998	ret = spi_master_resume(master);
1999	if (ret) {
2000		clk_disable_unprepare(spi->clk);
2001		return ret;
2002	}
2003
2004	ret = pm_runtime_resume_and_get(dev);
2005	if (ret < 0) {
 
2006		dev_err(dev, "Unable to power device:%d\n", ret);
2007		return ret;
2008	}
2009
2010	spi->cfg->config(spi);
2011
2012	pm_runtime_mark_last_busy(dev);
2013	pm_runtime_put_autosuspend(dev);
2014
2015	return 0;
2016}
2017
2018static const struct dev_pm_ops stm32_spi_pm_ops = {
2019	SET_SYSTEM_SLEEP_PM_OPS(stm32_spi_suspend, stm32_spi_resume)
2020	SET_RUNTIME_PM_OPS(stm32_spi_runtime_suspend,
2021			   stm32_spi_runtime_resume, NULL)
2022};
2023
2024static struct platform_driver stm32_spi_driver = {
2025	.probe = stm32_spi_probe,
2026	.remove = stm32_spi_remove,
2027	.driver = {
2028		.name = DRIVER_NAME,
2029		.pm = &stm32_spi_pm_ops,
2030		.of_match_table = stm32_spi_of_match,
2031	},
2032};
2033
2034module_platform_driver(stm32_spi_driver);
2035
2036MODULE_ALIAS("platform:" DRIVER_NAME);
2037MODULE_DESCRIPTION("STMicroelectronics STM32 SPI Controller driver");
2038MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
2039MODULE_LICENSE("GPL v2");