xref: /linux/drivers/spi/spi-stm32.c (revision 78c3925c048c752334873f56c3a3d1c9d53e0416)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // STMicroelectronics STM32 SPI Controller driver
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.h>
17 #include <linux/platform_device.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/reset.h>
21 #include <linux/spi/spi.h>
22 
23 #define DRIVER_NAME "spi_stm32"
24 
25 /* STM32F4/7 SPI registers */
26 #define STM32FX_SPI_CR1			0x00
27 #define STM32FX_SPI_CR2			0x04
28 #define STM32FX_SPI_SR			0x08
29 #define STM32FX_SPI_DR			0x0C
30 #define STM32FX_SPI_I2SCFGR		0x1C
31 
32 /* STM32FX_SPI_CR1 bit fields */
33 #define STM32FX_SPI_CR1_CPHA		BIT(0)
34 #define STM32FX_SPI_CR1_CPOL		BIT(1)
35 #define STM32FX_SPI_CR1_MSTR		BIT(2)
36 #define STM32FX_SPI_CR1_BR_SHIFT	3
37 #define STM32FX_SPI_CR1_BR		GENMASK(5, 3)
38 #define STM32FX_SPI_CR1_SPE		BIT(6)
39 #define STM32FX_SPI_CR1_LSBFRST		BIT(7)
40 #define STM32FX_SPI_CR1_SSI		BIT(8)
41 #define STM32FX_SPI_CR1_SSM		BIT(9)
42 #define STM32FX_SPI_CR1_RXONLY		BIT(10)
43 #define STM32F4_SPI_CR1_DFF		BIT(11)
44 #define STM32F7_SPI_CR1_CRCL		BIT(11)
45 #define STM32FX_SPI_CR1_CRCNEXT		BIT(12)
46 #define STM32FX_SPI_CR1_CRCEN		BIT(13)
47 #define STM32FX_SPI_CR1_BIDIOE		BIT(14)
48 #define STM32FX_SPI_CR1_BIDIMODE	BIT(15)
49 #define STM32FX_SPI_CR1_BR_MIN		0
50 #define STM32FX_SPI_CR1_BR_MAX		(GENMASK(5, 3) >> 3)
51 
52 /* STM32FX_SPI_CR2 bit fields */
53 #define STM32FX_SPI_CR2_RXDMAEN		BIT(0)
54 #define STM32FX_SPI_CR2_TXDMAEN		BIT(1)
55 #define STM32FX_SPI_CR2_SSOE		BIT(2)
56 #define STM32FX_SPI_CR2_FRF		BIT(4)
57 #define STM32FX_SPI_CR2_ERRIE		BIT(5)
58 #define STM32FX_SPI_CR2_RXNEIE		BIT(6)
59 #define STM32FX_SPI_CR2_TXEIE		BIT(7)
60 #define STM32F7_SPI_CR2_DS		GENMASK(11, 8)
61 #define STM32F7_SPI_CR2_FRXTH		BIT(12)
62 #define STM32F7_SPI_CR2_LDMA_RX		BIT(13)
63 #define STM32F7_SPI_CR2_LDMA_TX		BIT(14)
64 
65 /* STM32FX_SPI_SR bit fields */
66 #define STM32FX_SPI_SR_RXNE		BIT(0)
67 #define STM32FX_SPI_SR_TXE		BIT(1)
68 #define STM32FX_SPI_SR_CHSIDE		BIT(2)
69 #define STM32FX_SPI_SR_UDR		BIT(3)
70 #define STM32FX_SPI_SR_CRCERR		BIT(4)
71 #define STM32FX_SPI_SR_MODF		BIT(5)
72 #define STM32FX_SPI_SR_OVR		BIT(6)
73 #define STM32FX_SPI_SR_BSY		BIT(7)
74 #define STM32FX_SPI_SR_FRE		BIT(8)
75 #define STM32F7_SPI_SR_FRLVL		GENMASK(10, 9)
76 #define STM32F7_SPI_SR_FTLVL		GENMASK(12, 11)
77 
78 /* STM32FX_SPI_I2SCFGR bit fields */
79 #define STM32FX_SPI_I2SCFGR_I2SMOD	BIT(11)
80 
81 /* STM32F4 SPI Baud Rate min/max divisor */
82 #define STM32FX_SPI_BR_DIV_MIN		(2 << STM32FX_SPI_CR1_BR_MIN)
83 #define STM32FX_SPI_BR_DIV_MAX		(2 << STM32FX_SPI_CR1_BR_MAX)
84 
85 /* STM32H7 SPI registers */
86 #define STM32H7_SPI_CR1			0x00
87 #define STM32H7_SPI_CR2			0x04
88 #define STM32H7_SPI_CFG1		0x08
89 #define STM32H7_SPI_CFG2		0x0C
90 #define STM32H7_SPI_IER			0x10
91 #define STM32H7_SPI_SR			0x14
92 #define STM32H7_SPI_IFCR		0x18
93 #define STM32H7_SPI_TXDR		0x20
94 #define STM32H7_SPI_RXDR		0x30
95 #define STM32H7_SPI_I2SCFGR		0x50
96 
97 /* STM32H7_SPI_CR1 bit fields */
98 #define STM32H7_SPI_CR1_SPE		BIT(0)
99 #define STM32H7_SPI_CR1_MASRX		BIT(8)
100 #define STM32H7_SPI_CR1_CSTART		BIT(9)
101 #define STM32H7_SPI_CR1_CSUSP		BIT(10)
102 #define STM32H7_SPI_CR1_HDDIR		BIT(11)
103 #define STM32H7_SPI_CR1_SSI		BIT(12)
104 
105 /* STM32H7_SPI_CR2 bit fields */
106 #define STM32H7_SPI_CR2_TSIZE		GENMASK(15, 0)
107 #define STM32H7_SPI_TSIZE_MAX		GENMASK(15, 0)
108 
109 /* STM32H7_SPI_CFG1 bit fields */
110 #define STM32H7_SPI_CFG1_DSIZE		GENMASK(4, 0)
111 #define STM32H7_SPI_CFG1_FTHLV		GENMASK(8, 5)
112 #define STM32H7_SPI_CFG1_RXDMAEN	BIT(14)
113 #define STM32H7_SPI_CFG1_TXDMAEN	BIT(15)
114 #define STM32H7_SPI_CFG1_MBR		GENMASK(30, 28)
115 #define STM32H7_SPI_CFG1_MBR_SHIFT	28
116 #define STM32H7_SPI_CFG1_MBR_MIN	0
117 #define STM32H7_SPI_CFG1_MBR_MAX	(GENMASK(30, 28) >> 28)
118 
119 /* STM32H7_SPI_CFG2 bit fields */
120 #define STM32H7_SPI_CFG2_MIDI		GENMASK(7, 4)
121 #define STM32H7_SPI_CFG2_COMM		GENMASK(18, 17)
122 #define STM32H7_SPI_CFG2_SP		GENMASK(21, 19)
123 #define STM32H7_SPI_CFG2_MASTER		BIT(22)
124 #define STM32H7_SPI_CFG2_LSBFRST	BIT(23)
125 #define STM32H7_SPI_CFG2_CPHA		BIT(24)
126 #define STM32H7_SPI_CFG2_CPOL		BIT(25)
127 #define STM32H7_SPI_CFG2_SSM		BIT(26)
128 #define STM32H7_SPI_CFG2_SSIOP		BIT(28)
129 #define STM32H7_SPI_CFG2_AFCNTR		BIT(31)
130 
131 /* STM32H7_SPI_IER bit fields */
132 #define STM32H7_SPI_IER_RXPIE		BIT(0)
133 #define STM32H7_SPI_IER_TXPIE		BIT(1)
134 #define STM32H7_SPI_IER_DXPIE		BIT(2)
135 #define STM32H7_SPI_IER_EOTIE		BIT(3)
136 #define STM32H7_SPI_IER_TXTFIE		BIT(4)
137 #define STM32H7_SPI_IER_OVRIE		BIT(6)
138 #define STM32H7_SPI_IER_MODFIE		BIT(9)
139 #define STM32H7_SPI_IER_ALL		GENMASK(10, 0)
140 
141 /* STM32H7_SPI_SR bit fields */
142 #define STM32H7_SPI_SR_RXP		BIT(0)
143 #define STM32H7_SPI_SR_TXP		BIT(1)
144 #define STM32H7_SPI_SR_EOT		BIT(3)
145 #define STM32H7_SPI_SR_OVR		BIT(6)
146 #define STM32H7_SPI_SR_MODF		BIT(9)
147 #define STM32H7_SPI_SR_SUSP		BIT(11)
148 #define STM32H7_SPI_SR_RXPLVL		GENMASK(14, 13)
149 #define STM32H7_SPI_SR_RXWNE		BIT(15)
150 
151 /* STM32H7_SPI_IFCR bit fields */
152 #define STM32H7_SPI_IFCR_ALL		GENMASK(11, 3)
153 
154 /* STM32H7_SPI_I2SCFGR bit fields */
155 #define STM32H7_SPI_I2SCFGR_I2SMOD	BIT(0)
156 
157 /* STM32MP25 SPI registers bit fields */
158 #define STM32MP25_SPI_HWCFGR1			0x3F0
159 
160 /* STM32MP25_SPI_CR2 bit fields */
161 #define STM32MP25_SPI_TSIZE_MAX_LIMITED		GENMASK(9, 0)
162 
163 /* STM32MP25_SPI_HWCFGR1 */
164 #define STM32MP25_SPI_HWCFGR1_FULLCFG		GENMASK(27, 24)
165 #define STM32MP25_SPI_HWCFGR1_FULLCFG_LIMITED	0x0
166 #define STM32MP25_SPI_HWCFGR1_FULLCFG_FULL	0x1
167 #define STM32MP25_SPI_HWCFGR1_DSCFG		GENMASK(19, 16)
168 #define STM32MP25_SPI_HWCFGR1_DSCFG_16_B	0x0
169 #define STM32MP25_SPI_HWCFGR1_DSCFG_32_B	0x1
170 
171 /* STM32H7 SPI Master Baud Rate min/max divisor */
172 #define STM32H7_SPI_MBR_DIV_MIN		(2 << STM32H7_SPI_CFG1_MBR_MIN)
173 #define STM32H7_SPI_MBR_DIV_MAX		(2 << STM32H7_SPI_CFG1_MBR_MAX)
174 
175 /* STM32H7 SPI Communication mode */
176 #define STM32H7_SPI_FULL_DUPLEX		0
177 #define STM32H7_SPI_SIMPLEX_TX		1
178 #define STM32H7_SPI_SIMPLEX_RX		2
179 #define STM32H7_SPI_HALF_DUPLEX		3
180 
181 /* SPI Communication type */
182 #define SPI_FULL_DUPLEX		0
183 #define SPI_SIMPLEX_TX		1
184 #define SPI_SIMPLEX_RX		2
185 #define SPI_3WIRE_TX		3
186 #define SPI_3WIRE_RX		4
187 
188 #define STM32_SPI_AUTOSUSPEND_DELAY		1	/* 1 ms */
189 
190 /*
191  * use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers
192  * without fifo buffers.
193  */
194 #define SPI_DMA_MIN_BYTES	16
195 
196 /* STM32 SPI driver helpers */
197 #define STM32_SPI_HOST_MODE(stm32_spi) (!(stm32_spi)->device_mode)
198 #define STM32_SPI_DEVICE_MODE(stm32_spi) ((stm32_spi)->device_mode)
199 
200 /**
201  * struct stm32_spi_reg - stm32 SPI register & bitfield desc
202  * @reg:		register offset
203  * @mask:		bitfield mask
204  * @shift:		left shift
205  */
206 struct stm32_spi_reg {
207 	int reg;
208 	int mask;
209 	int shift;
210 };
211 
212 /**
213  * struct stm32_spi_regspec - stm32 registers definition, compatible dependent data
214  * @en: enable register and SPI enable bit
215  * @dma_rx_en: SPI DMA RX enable register end SPI DMA RX enable bit
216  * @dma_tx_en: SPI DMA TX enable register end SPI DMA TX enable bit
217  * @cpol: clock polarity register and polarity bit
218  * @cpha: clock phase register and phase bit
219  * @lsb_first: LSB transmitted first register and bit
220  * @cs_high: chips select active value
221  * @br: baud rate register and bitfields
222  * @rx: SPI RX data register
223  * @tx: SPI TX data register
224  * @fullcfg: SPI full or limited feature set register
225  */
226 struct stm32_spi_regspec {
227 	const struct stm32_spi_reg en;
228 	const struct stm32_spi_reg dma_rx_en;
229 	const struct stm32_spi_reg dma_tx_en;
230 	const struct stm32_spi_reg cpol;
231 	const struct stm32_spi_reg cpha;
232 	const struct stm32_spi_reg lsb_first;
233 	const struct stm32_spi_reg cs_high;
234 	const struct stm32_spi_reg br;
235 	const struct stm32_spi_reg rx;
236 	const struct stm32_spi_reg tx;
237 	const struct stm32_spi_reg fullcfg;
238 };
239 
240 struct stm32_spi;
241 
242 /**
243  * struct stm32_spi_cfg - stm32 compatible configuration data
244  * @regs: registers descriptions
245  * @get_fifo_size: routine to get fifo size
246  * @get_bpw_mask: routine to get bits per word mask
247  * @disable: routine to disable controller
248  * @config: routine to configure controller as SPI Host
249  * @set_bpw: routine to configure registers to for bits per word
250  * @set_mode: routine to configure registers to desired mode
251  * @set_data_idleness: optional routine to configure registers to desired idle
252  * time between frames (if driver has this functionality)
253  * @set_number_of_data: optional routine to configure registers to desired
254  * number of data (if driver has this functionality)
255  * @write_tx: routine to write to transmit register/FIFO
256  * @read_rx: routine to read from receive register/FIFO
257  * @transfer_one_dma_start: routine to start transfer a single spi_transfer
258  * using DMA
259  * @dma_rx_cb: routine to call after DMA RX channel operation is complete
260  * @dma_tx_cb: routine to call after DMA TX channel operation is complete
261  * @transfer_one_irq: routine to configure interrupts for driver
262  * @irq_handler_event: Interrupt handler for SPI controller events
263  * @irq_handler_thread: thread of interrupt handler for SPI controller
264  * @baud_rate_div_min: minimum baud rate divisor
265  * @baud_rate_div_max: maximum baud rate divisor
266  * @has_fifo: boolean to know if fifo is used for driver
267  * @has_device_mode: is this compatible capable to switch on device mode
268  * @flags: compatible specific SPI controller flags used at registration time
269  * @prevent_dma_burst: boolean to indicate to prevent DMA burst
270  */
271 struct stm32_spi_cfg {
272 	const struct stm32_spi_regspec *regs;
273 	int (*get_fifo_size)(struct stm32_spi *spi);
274 	int (*get_bpw_mask)(struct stm32_spi *spi);
275 	void (*disable)(struct stm32_spi *spi);
276 	int (*config)(struct stm32_spi *spi);
277 	void (*set_bpw)(struct stm32_spi *spi);
278 	int (*set_mode)(struct stm32_spi *spi, unsigned int comm_type);
279 	void (*set_data_idleness)(struct stm32_spi *spi, u32 length);
280 	int (*set_number_of_data)(struct stm32_spi *spi, u32 length);
281 	void (*write_tx)(struct stm32_spi *spi);
282 	void (*read_rx)(struct stm32_spi *spi);
283 	void (*transfer_one_dma_start)(struct stm32_spi *spi);
284 	void (*dma_rx_cb)(void *data);
285 	void (*dma_tx_cb)(void *data);
286 	int (*transfer_one_irq)(struct stm32_spi *spi);
287 	irqreturn_t (*irq_handler_event)(int irq, void *dev_id);
288 	irqreturn_t (*irq_handler_thread)(int irq, void *dev_id);
289 	unsigned int baud_rate_div_min;
290 	unsigned int baud_rate_div_max;
291 	bool has_fifo;
292 	bool has_device_mode;
293 	u16 flags;
294 	bool prevent_dma_burst;
295 };
296 
297 /**
298  * struct stm32_spi - private data of the SPI controller
299  * @dev: driver model representation of the controller
300  * @ctrl: controller interface
301  * @cfg: compatible configuration data
302  * @base: virtual memory area
303  * @clk: hw kernel clock feeding the SPI clock generator
304  * @clk_rate: rate of the hw kernel clock feeding the SPI clock generator
305  * @lock: prevent I/O concurrent access
306  * @irq: SPI controller interrupt line
307  * @fifo_size: size of the embedded fifo in bytes
308  * @t_size_max: maximum number of data of one transfer
309  * @feature_set: SPI full or limited feature set
310  * @cur_midi: host inter-data idleness in ns
311  * @cur_speed: speed configured in Hz
312  * @cur_half_period: time of a half bit in us
313  * @cur_bpw: number of bits in a single SPI data frame
314  * @cur_fthlv: fifo threshold level (data frames in a single data packet)
315  * @cur_comm: SPI communication mode
316  * @cur_xferlen: current transfer length in bytes
317  * @cur_usedma: boolean to know if dma is used in current transfer
318  * @tx_buf: data to be written, or NULL
319  * @rx_buf: data to be read, or NULL
320  * @tx_len: number of data to be written in bytes
321  * @rx_len: number of data to be read in bytes
322  * @dma_tx: dma channel for TX transfer
323  * @dma_rx: dma channel for RX transfer
324  * @phys_addr: SPI registers physical base address
325  * @device_mode: the controller is configured as SPI device
326  */
327 struct stm32_spi {
328 	struct device *dev;
329 	struct spi_controller *ctrl;
330 	const struct stm32_spi_cfg *cfg;
331 	void __iomem *base;
332 	struct clk *clk;
333 	u32 clk_rate;
334 	spinlock_t lock; /* prevent I/O concurrent access */
335 	int irq;
336 	unsigned int fifo_size;
337 	unsigned int t_size_max;
338 	unsigned int feature_set;
339 #define STM32_SPI_FEATURE_LIMITED	STM32MP25_SPI_HWCFGR1_FULLCFG_LIMITED	/* 0x0 */
340 #define STM32_SPI_FEATURE_FULL		STM32MP25_SPI_HWCFGR1_FULLCFG_FULL	/* 0x1 */
341 
342 	unsigned int cur_midi;
343 	unsigned int cur_speed;
344 	unsigned int cur_half_period;
345 	unsigned int cur_bpw;
346 	unsigned int cur_fthlv;
347 	unsigned int cur_comm;
348 	unsigned int cur_xferlen;
349 	bool cur_usedma;
350 
351 	const void *tx_buf;
352 	void *rx_buf;
353 	int tx_len;
354 	int rx_len;
355 	struct dma_chan *dma_tx;
356 	struct dma_chan *dma_rx;
357 	dma_addr_t phys_addr;
358 
359 	bool device_mode;
360 };
361 
362 static const struct stm32_spi_regspec stm32fx_spi_regspec = {
363 	.en = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_SPE },
364 
365 	.dma_rx_en = { STM32FX_SPI_CR2, STM32FX_SPI_CR2_RXDMAEN },
366 	.dma_tx_en = { STM32FX_SPI_CR2, STM32FX_SPI_CR2_TXDMAEN },
367 
368 	.cpol = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_CPOL },
369 	.cpha = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_CPHA },
370 	.lsb_first = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_LSBFRST },
371 	.cs_high = {},
372 	.br = { STM32FX_SPI_CR1, STM32FX_SPI_CR1_BR, STM32FX_SPI_CR1_BR_SHIFT },
373 
374 	.rx = { STM32FX_SPI_DR },
375 	.tx = { STM32FX_SPI_DR },
376 };
377 
378 static const struct stm32_spi_regspec stm32h7_spi_regspec = {
379 	/* SPI data transfer is enabled but spi_ker_ck is idle.
380 	 * CFG1 and CFG2 registers are write protected when SPE is enabled.
381 	 */
382 	.en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
383 
384 	.dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
385 	.dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
386 
387 	.cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
388 	.cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
389 	.lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
390 	.cs_high = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_SSIOP },
391 	.br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
392 		STM32H7_SPI_CFG1_MBR_SHIFT },
393 
394 	.rx = { STM32H7_SPI_RXDR },
395 	.tx = { STM32H7_SPI_TXDR },
396 };
397 
398 static const struct stm32_spi_regspec stm32mp25_spi_regspec = {
399 	/* SPI data transfer is enabled but spi_ker_ck is idle.
400 	 * CFG1 and CFG2 registers are write protected when SPE is enabled.
401 	 */
402 	.en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE },
403 
404 	.dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN },
405 	.dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN },
406 
407 	.cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL },
408 	.cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA },
409 	.lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST },
410 	.cs_high = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_SSIOP },
411 	.br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR,
412 		STM32H7_SPI_CFG1_MBR_SHIFT },
413 
414 	.rx = { STM32H7_SPI_RXDR },
415 	.tx = { STM32H7_SPI_TXDR },
416 
417 	.fullcfg = { STM32MP25_SPI_HWCFGR1, STM32MP25_SPI_HWCFGR1_FULLCFG },
418 };
419 
420 static inline void stm32_spi_set_bits(struct stm32_spi *spi,
421 				      u32 offset, u32 bits)
422 {
423 	writel_relaxed(readl_relaxed(spi->base + offset) | bits,
424 		       spi->base + offset);
425 }
426 
427 static inline void stm32_spi_clr_bits(struct stm32_spi *spi,
428 				      u32 offset, u32 bits)
429 {
430 	writel_relaxed(readl_relaxed(spi->base + offset) & ~bits,
431 		       spi->base + offset);
432 }
433 
434 /**
435  * stm32h7_spi_get_fifo_size - Return fifo size
436  * @spi: pointer to the spi controller data structure
437  */
438 static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi)
439 {
440 	unsigned long flags;
441 	u32 count = 0;
442 
443 	spin_lock_irqsave(&spi->lock, flags);
444 
445 	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
446 
447 	while (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP)
448 		writeb_relaxed(++count, spi->base + STM32H7_SPI_TXDR);
449 
450 	stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
451 
452 	spin_unlock_irqrestore(&spi->lock, flags);
453 
454 	dev_dbg(spi->dev, "%d x 8-bit fifo size\n", count);
455 
456 	return count;
457 }
458 
459 /**
460  * stm32f4_spi_get_bpw_mask - Return bits per word mask
461  * @spi: pointer to the spi controller data structure
462  */
463 static int stm32f4_spi_get_bpw_mask(struct stm32_spi *spi)
464 {
465 	dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
466 	return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
467 }
468 
469 /**
470  * stm32f7_spi_get_bpw_mask - Return bits per word mask
471  * @spi: pointer to the spi controller data structure
472  */
473 static int stm32f7_spi_get_bpw_mask(struct stm32_spi *spi)
474 {
475 	dev_dbg(spi->dev, "16-bit maximum data frame\n");
476 	return SPI_BPW_RANGE_MASK(4, 16);
477 }
478 
479 /**
480  * stm32h7_spi_get_bpw_mask - Return bits per word mask
481  * @spi: pointer to the spi controller data structure
482  */
483 static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi)
484 {
485 	unsigned long flags;
486 	u32 cfg1, max_bpw;
487 
488 	spin_lock_irqsave(&spi->lock, flags);
489 
490 	/*
491 	 * The most significant bit at DSIZE bit field is reserved when the
492 	 * maximum data size of periperal instances is limited to 16-bit
493 	 */
494 	stm32_spi_set_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_DSIZE);
495 
496 	cfg1 = readl_relaxed(spi->base + STM32H7_SPI_CFG1);
497 	max_bpw = FIELD_GET(STM32H7_SPI_CFG1_DSIZE, cfg1) + 1;
498 
499 	spin_unlock_irqrestore(&spi->lock, flags);
500 
501 	dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw);
502 
503 	return SPI_BPW_RANGE_MASK(4, max_bpw);
504 }
505 
506 /**
507  * stm32mp25_spi_get_bpw_mask - Return bits per word mask
508  * @spi: pointer to the spi controller data structure
509  */
510 static int stm32mp25_spi_get_bpw_mask(struct stm32_spi *spi)
511 {
512 	u32 dscfg, max_bpw;
513 
514 	if (spi->feature_set == STM32_SPI_FEATURE_LIMITED) {
515 		dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n");
516 		return SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
517 	}
518 
519 	dscfg = FIELD_GET(STM32MP25_SPI_HWCFGR1_DSCFG,
520 			  readl_relaxed(spi->base + STM32MP25_SPI_HWCFGR1));
521 	max_bpw = 16;
522 	if (dscfg == STM32MP25_SPI_HWCFGR1_DSCFG_32_B)
523 		max_bpw = 32;
524 	dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw);
525 	return SPI_BPW_RANGE_MASK(4, max_bpw);
526 }
527 
528 /**
529  * stm32_spi_prepare_mbr - Determine baud rate divisor value
530  * @spi: pointer to the spi controller data structure
531  * @speed_hz: requested speed
532  * @min_div: minimum baud rate divisor
533  * @max_div: maximum baud rate divisor
534  *
535  * Return baud rate divisor value in case of success or -EINVAL
536  */
537 static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
538 				 u32 min_div, u32 max_div)
539 {
540 	u32 div, mbrdiv;
541 
542 	/* Ensure spi->clk_rate is even */
543 	div = DIV_ROUND_CLOSEST(spi->clk_rate & ~0x1, speed_hz);
544 
545 	/*
546 	 * SPI framework set xfer->speed_hz to ctrl->max_speed_hz if
547 	 * xfer->speed_hz is greater than ctrl->max_speed_hz, and it returns
548 	 * an error when xfer->speed_hz is lower than ctrl->min_speed_hz, so
549 	 * no need to check it there.
550 	 * However, we need to ensure the following calculations.
551 	 */
552 	if ((div < min_div) || (div > max_div))
553 		return -EINVAL;
554 
555 	/* Determine the first power of 2 greater than or equal to div */
556 	if (div & (div - 1))
557 		mbrdiv = fls(div);
558 	else
559 		mbrdiv = fls(div) - 1;
560 
561 	spi->cur_speed = spi->clk_rate / (1 << mbrdiv);
562 
563 	spi->cur_half_period = DIV_ROUND_CLOSEST(USEC_PER_SEC, 2 * spi->cur_speed);
564 
565 	return mbrdiv - 1;
566 }
567 
568 /**
569  * stm32h7_spi_prepare_fthlv - Determine FIFO threshold level
570  * @spi: pointer to the spi controller data structure
571  * @xfer_len: length of the message to be transferred
572  */
573 static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len)
574 {
575 	u32 packet, bpw;
576 
577 	/* data packet should not exceed 1/2 of fifo space */
578 	packet = clamp(xfer_len, 1U, spi->fifo_size / 2);
579 
580 	/* align packet size with data registers access */
581 	bpw = DIV_ROUND_UP(spi->cur_bpw, 8);
582 	return DIV_ROUND_UP(packet, bpw);
583 }
584 
585 /**
586  * stm32f4_spi_write_tx - Write bytes to Transmit Data Register
587  * @spi: pointer to the spi controller data structure
588  *
589  * Read from tx_buf depends on remaining bytes to avoid to read beyond
590  * tx_buf end.
591  */
592 static void stm32f4_spi_write_tx(struct stm32_spi *spi)
593 {
594 	if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32FX_SPI_SR) &
595 				  STM32FX_SPI_SR_TXE)) {
596 		u32 offs = spi->cur_xferlen - spi->tx_len;
597 
598 		if (spi->cur_bpw == 16) {
599 			const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
600 
601 			writew_relaxed(*tx_buf16, spi->base + STM32FX_SPI_DR);
602 			spi->tx_len -= sizeof(u16);
603 		} else {
604 			const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
605 
606 			writeb_relaxed(*tx_buf8, spi->base + STM32FX_SPI_DR);
607 			spi->tx_len -= sizeof(u8);
608 		}
609 	}
610 
611 	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
612 }
613 
614 /**
615  * stm32f7_spi_write_tx - Write bytes to Transmit Data Register
616  * @spi: pointer to the spi controller data structure
617  *
618  * Read from tx_buf depends on remaining bytes to avoid to read beyond
619  * tx_buf end.
620  */
621 static void stm32f7_spi_write_tx(struct stm32_spi *spi)
622 {
623 	if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32FX_SPI_SR) &
624 				  STM32FX_SPI_SR_TXE)) {
625 		u32 offs = spi->cur_xferlen - spi->tx_len;
626 
627 		if (spi->tx_len >= sizeof(u16)) {
628 			const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
629 
630 			writew_relaxed(*tx_buf16, spi->base + STM32FX_SPI_DR);
631 			spi->tx_len -= sizeof(u16);
632 		} else {
633 			const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
634 
635 			writeb_relaxed(*tx_buf8, spi->base + STM32FX_SPI_DR);
636 			spi->tx_len -= sizeof(u8);
637 		}
638 	}
639 
640 	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
641 }
642 
643 /**
644  * stm32h7_spi_write_txfifo - Write bytes in Transmit Data Register
645  * @spi: pointer to the spi controller data structure
646  *
647  * Read from tx_buf depends on remaining bytes to avoid to read beyond
648  * tx_buf end.
649  */
650 static void stm32h7_spi_write_txfifo(struct stm32_spi *spi)
651 {
652 	while ((spi->tx_len > 0) &&
653 		       (readl_relaxed(spi->base + STM32H7_SPI_SR) &
654 			STM32H7_SPI_SR_TXP)) {
655 		u32 offs = spi->cur_xferlen - spi->tx_len;
656 
657 		if (spi->tx_len >= sizeof(u32)) {
658 			const u32 *tx_buf32 = (const u32 *)(spi->tx_buf + offs);
659 
660 			writel_relaxed(*tx_buf32, spi->base + STM32H7_SPI_TXDR);
661 			spi->tx_len -= sizeof(u32);
662 		} else if (spi->tx_len >= sizeof(u16)) {
663 			const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs);
664 
665 			writew_relaxed(*tx_buf16, spi->base + STM32H7_SPI_TXDR);
666 			spi->tx_len -= sizeof(u16);
667 		} else {
668 			const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs);
669 
670 			writeb_relaxed(*tx_buf8, spi->base + STM32H7_SPI_TXDR);
671 			spi->tx_len -= sizeof(u8);
672 		}
673 	}
674 
675 	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len);
676 }
677 
678 /**
679  * stm32f4_spi_read_rx - Read bytes from Receive Data Register
680  * @spi: pointer to the spi controller data structure
681  *
682  * Write in rx_buf depends on remaining bytes to avoid to write beyond
683  * rx_buf end.
684  */
685 static void stm32f4_spi_read_rx(struct stm32_spi *spi)
686 {
687 	if ((spi->rx_len > 0) && (readl_relaxed(spi->base + STM32FX_SPI_SR) &
688 				  STM32FX_SPI_SR_RXNE)) {
689 		u32 offs = spi->cur_xferlen - spi->rx_len;
690 
691 		if (spi->cur_bpw == 16) {
692 			u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
693 
694 			*rx_buf16 = readw_relaxed(spi->base + STM32FX_SPI_DR);
695 			spi->rx_len -= sizeof(u16);
696 		} else {
697 			u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
698 
699 			*rx_buf8 = readb_relaxed(spi->base + STM32FX_SPI_DR);
700 			spi->rx_len -= sizeof(u8);
701 		}
702 	}
703 
704 	dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->rx_len);
705 }
706 
707 /**
708  * stm32f7_spi_read_rx - Read bytes from Receive Data Register
709  * @spi: pointer to the spi controller data structure
710  *
711  * Write in rx_buf depends on remaining bytes to avoid to write beyond
712  * rx_buf end.
713  */
714 static void stm32f7_spi_read_rx(struct stm32_spi *spi)
715 {
716 	u32 sr = readl_relaxed(spi->base + STM32FX_SPI_SR);
717 	u32 frlvl = FIELD_GET(STM32F7_SPI_SR_FRLVL, sr);
718 
719 	while ((spi->rx_len > 0) && (frlvl > 0)) {
720 		u32 offs = spi->cur_xferlen - spi->rx_len;
721 
722 		if ((spi->rx_len >= sizeof(u16)) && (frlvl >= 2)) {
723 			u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
724 
725 			*rx_buf16 = readw_relaxed(spi->base + STM32FX_SPI_DR);
726 			spi->rx_len -= sizeof(u16);
727 		} else {
728 			u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
729 
730 			*rx_buf8 = readb_relaxed(spi->base + STM32FX_SPI_DR);
731 			spi->rx_len -= sizeof(u8);
732 		}
733 
734 		sr = readl_relaxed(spi->base + STM32FX_SPI_SR);
735 		frlvl = FIELD_GET(STM32F7_SPI_SR_FRLVL, sr);
736 	}
737 
738 	if (spi->rx_len >= sizeof(u16))
739 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
740 	else
741 		stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
742 
743 	dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n",
744 		__func__, spi->rx_len, sr);
745 }
746 
747 /**
748  * stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register
749  * @spi: pointer to the spi controller data structure
750  *
751  * Write in rx_buf depends on remaining bytes to avoid to write beyond
752  * rx_buf end.
753  */
754 static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi)
755 {
756 	u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
757 	u32 rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
758 
759 	while ((spi->rx_len > 0) &&
760 	       ((sr & STM32H7_SPI_SR_RXP) ||
761 		((sr & STM32H7_SPI_SR_EOT) &&
762 		 ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) {
763 		u32 offs = spi->cur_xferlen - spi->rx_len;
764 
765 		if ((spi->rx_len >= sizeof(u32)) ||
766 		    (sr & STM32H7_SPI_SR_RXWNE)) {
767 			u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs);
768 
769 			*rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR);
770 			spi->rx_len -= sizeof(u32);
771 		} else if ((spi->rx_len >= sizeof(u16)) ||
772 			   (!(sr & STM32H7_SPI_SR_RXWNE) &&
773 			    (rxplvl >= 2 || spi->cur_bpw > 8))) {
774 			u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs);
775 
776 			*rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR);
777 			spi->rx_len -= sizeof(u16);
778 		} else {
779 			u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs);
780 
781 			*rx_buf8 = readb_relaxed(spi->base + STM32H7_SPI_RXDR);
782 			spi->rx_len -= sizeof(u8);
783 		}
784 
785 		sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
786 		rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr);
787 	}
788 
789 	dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n",
790 		__func__, spi->rx_len, sr);
791 }
792 
793 /**
794  * stm32_spi_enable - Enable SPI controller
795  * @spi: pointer to the spi controller data structure
796  */
797 static void stm32_spi_enable(struct stm32_spi *spi)
798 {
799 	dev_dbg(spi->dev, "enable controller\n");
800 
801 	stm32_spi_set_bits(spi, spi->cfg->regs->en.reg,
802 			   spi->cfg->regs->en.mask);
803 }
804 
805 /**
806  * stm32fx_spi_disable - Disable SPI controller
807  * @spi: pointer to the spi controller data structure
808  */
809 static void stm32fx_spi_disable(struct stm32_spi *spi)
810 {
811 	unsigned long flags;
812 	u32 sr;
813 
814 	dev_dbg(spi->dev, "disable controller\n");
815 
816 	spin_lock_irqsave(&spi->lock, flags);
817 
818 	if (!(readl_relaxed(spi->base + STM32FX_SPI_CR1) &
819 	      STM32FX_SPI_CR1_SPE)) {
820 		spin_unlock_irqrestore(&spi->lock, flags);
821 		return;
822 	}
823 
824 	/* Disable interrupts */
825 	stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_TXEIE |
826 						 STM32FX_SPI_CR2_RXNEIE |
827 						 STM32FX_SPI_CR2_ERRIE);
828 
829 	/* Wait until BSY = 0 */
830 	if (readl_relaxed_poll_timeout_atomic(spi->base + STM32FX_SPI_SR,
831 					      sr, !(sr & STM32FX_SPI_SR_BSY),
832 					      10, 100000) < 0) {
833 		dev_warn(spi->dev, "disabling condition timeout\n");
834 	}
835 
836 	if (spi->cur_usedma && spi->dma_tx)
837 		dmaengine_terminate_async(spi->dma_tx);
838 	if (spi->cur_usedma && spi->dma_rx)
839 		dmaengine_terminate_async(spi->dma_rx);
840 
841 	stm32_spi_clr_bits(spi, STM32FX_SPI_CR1, STM32FX_SPI_CR1_SPE);
842 
843 	stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_TXDMAEN |
844 						 STM32FX_SPI_CR2_RXDMAEN);
845 
846 	/* Sequence to clear OVR flag */
847 	readl_relaxed(spi->base + STM32FX_SPI_DR);
848 	readl_relaxed(spi->base + STM32FX_SPI_SR);
849 
850 	spin_unlock_irqrestore(&spi->lock, flags);
851 }
852 
853 /**
854  * stm32h7_spi_disable - Disable SPI controller
855  * @spi: pointer to the spi controller data structure
856  *
857  * RX-Fifo is flushed when SPI controller is disabled.
858  */
859 static void stm32h7_spi_disable(struct stm32_spi *spi)
860 {
861 	unsigned long flags;
862 	u32 cr1;
863 
864 	dev_dbg(spi->dev, "disable controller\n");
865 
866 	spin_lock_irqsave(&spi->lock, flags);
867 
868 	cr1 = readl_relaxed(spi->base + STM32H7_SPI_CR1);
869 
870 	if (!(cr1 & STM32H7_SPI_CR1_SPE)) {
871 		spin_unlock_irqrestore(&spi->lock, flags);
872 		return;
873 	}
874 
875 	/* Add a delay to make sure that transmission is ended. */
876 	if (spi->cur_half_period)
877 		udelay(spi->cur_half_period);
878 
879 	if (spi->cur_usedma && spi->dma_tx)
880 		dmaengine_terminate_async(spi->dma_tx);
881 	if (spi->cur_usedma && spi->dma_rx)
882 		dmaengine_terminate_async(spi->dma_rx);
883 
884 	stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE);
885 
886 	stm32_spi_clr_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN |
887 						STM32H7_SPI_CFG1_RXDMAEN);
888 
889 	/* Disable interrupts and clear status flags */
890 	writel_relaxed(0, spi->base + STM32H7_SPI_IER);
891 	writel_relaxed(STM32H7_SPI_IFCR_ALL, spi->base + STM32H7_SPI_IFCR);
892 
893 	spin_unlock_irqrestore(&spi->lock, flags);
894 }
895 
896 /**
897  * stm32_spi_can_dma - Determine if the transfer is eligible for DMA use
898  * @ctrl: controller interface
899  * @spi_dev: pointer to the spi device
900  * @transfer: pointer to spi transfer
901  *
902  * If driver has fifo and the current transfer size is greater than fifo size,
903  * use DMA. Otherwise use DMA for transfer longer than defined DMA min bytes.
904  */
905 static bool stm32_spi_can_dma(struct spi_controller *ctrl,
906 			      struct spi_device *spi_dev,
907 			      struct spi_transfer *transfer)
908 {
909 	unsigned int dma_size;
910 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
911 
912 	if (spi->cfg->has_fifo)
913 		dma_size = spi->fifo_size;
914 	else
915 		dma_size = SPI_DMA_MIN_BYTES;
916 
917 	dev_dbg(spi->dev, "%s: %s\n", __func__,
918 		(transfer->len > dma_size) ? "true" : "false");
919 
920 	return (transfer->len > dma_size);
921 }
922 
923 /**
924  * stm32fx_spi_irq_event - Interrupt handler for SPI controller events
925  * @irq: interrupt line
926  * @dev_id: SPI controller ctrl interface
927  */
928 static irqreturn_t stm32fx_spi_irq_event(int irq, void *dev_id)
929 {
930 	struct spi_controller *ctrl = dev_id;
931 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
932 	u32 sr, mask = 0;
933 	bool end = false;
934 
935 	spin_lock(&spi->lock);
936 
937 	sr = readl_relaxed(spi->base + STM32FX_SPI_SR);
938 	/*
939 	 * BSY flag is not handled in interrupt but it is normal behavior when
940 	 * this flag is set.
941 	 */
942 	sr &= ~STM32FX_SPI_SR_BSY;
943 
944 	if (!spi->cur_usedma && (spi->cur_comm == SPI_SIMPLEX_TX ||
945 				 spi->cur_comm == SPI_3WIRE_TX)) {
946 		/* OVR flag shouldn't be handled for TX only mode */
947 		sr &= ~(STM32FX_SPI_SR_OVR | STM32FX_SPI_SR_RXNE);
948 		mask |= STM32FX_SPI_SR_TXE;
949 	}
950 
951 	if (!spi->cur_usedma && (spi->cur_comm == SPI_FULL_DUPLEX ||
952 				spi->cur_comm == SPI_SIMPLEX_RX ||
953 				spi->cur_comm == SPI_3WIRE_RX)) {
954 		/* TXE flag is set and is handled when RXNE flag occurs */
955 		sr &= ~STM32FX_SPI_SR_TXE;
956 		mask |= STM32FX_SPI_SR_RXNE | STM32FX_SPI_SR_OVR;
957 	}
958 
959 	if (!(sr & mask)) {
960 		dev_dbg(spi->dev, "spurious IT (sr=0x%08x)\n", sr);
961 		spin_unlock(&spi->lock);
962 		return IRQ_NONE;
963 	}
964 
965 	if (sr & STM32FX_SPI_SR_OVR) {
966 		dev_warn(spi->dev, "Overrun: received value discarded\n");
967 
968 		/* Sequence to clear OVR flag */
969 		readl_relaxed(spi->base + STM32FX_SPI_DR);
970 		readl_relaxed(spi->base + STM32FX_SPI_SR);
971 
972 		/*
973 		 * If overrun is detected, it means that something went wrong,
974 		 * so stop the current transfer. Transfer can wait for next
975 		 * RXNE but DR is already read and end never happens.
976 		 */
977 		end = true;
978 		goto end_irq;
979 	}
980 
981 	if (sr & STM32FX_SPI_SR_TXE) {
982 		if (spi->tx_buf)
983 			spi->cfg->write_tx(spi);
984 		if (spi->tx_len == 0)
985 			end = true;
986 	}
987 
988 	if (sr & STM32FX_SPI_SR_RXNE) {
989 		spi->cfg->read_rx(spi);
990 		if (spi->rx_len == 0)
991 			end = true;
992 		else if (spi->tx_buf)/* Load data for discontinuous mode */
993 			spi->cfg->write_tx(spi);
994 	}
995 
996 end_irq:
997 	if (end) {
998 		/* Immediately disable interrupts to do not generate new one */
999 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR2,
1000 					STM32FX_SPI_CR2_TXEIE |
1001 					STM32FX_SPI_CR2_RXNEIE |
1002 					STM32FX_SPI_CR2_ERRIE);
1003 		spin_unlock(&spi->lock);
1004 		return IRQ_WAKE_THREAD;
1005 	}
1006 
1007 	spin_unlock(&spi->lock);
1008 	return IRQ_HANDLED;
1009 }
1010 
1011 /**
1012  * stm32fx_spi_irq_thread - Thread of interrupt handler for SPI controller
1013  * @irq: interrupt line
1014  * @dev_id: SPI controller interface
1015  */
1016 static irqreturn_t stm32fx_spi_irq_thread(int irq, void *dev_id)
1017 {
1018 	struct spi_controller *ctrl = dev_id;
1019 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1020 
1021 	spi_finalize_current_transfer(ctrl);
1022 	stm32fx_spi_disable(spi);
1023 
1024 	return IRQ_HANDLED;
1025 }
1026 
1027 /**
1028  * stm32h7_spi_irq_thread - Thread of interrupt handler for SPI controller
1029  * @irq: interrupt line
1030  * @dev_id: SPI controller interface
1031  */
1032 static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
1033 {
1034 	struct spi_controller *ctrl = dev_id;
1035 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1036 	u32 sr, ier, mask;
1037 	unsigned long flags;
1038 	bool end = false;
1039 
1040 	spin_lock_irqsave(&spi->lock, flags);
1041 
1042 	sr = readl_relaxed(spi->base + STM32H7_SPI_SR);
1043 	ier = readl_relaxed(spi->base + STM32H7_SPI_IER);
1044 
1045 	mask = ier;
1046 	/*
1047 	 * EOTIE enables irq from EOT, SUSP and TXC events. We need to set
1048 	 * SUSP to acknowledge it later. TXC is automatically cleared
1049 	 */
1050 
1051 	mask |= STM32H7_SPI_SR_SUSP;
1052 	/*
1053 	 * DXPIE is set in Full-Duplex, one IT will be raised if TXP and RXP
1054 	 * are set. So in case of Full-Duplex, need to poll TXP and RXP event.
1055 	 */
1056 	if ((spi->cur_comm == SPI_FULL_DUPLEX) && !spi->cur_usedma)
1057 		mask |= STM32H7_SPI_SR_TXP | STM32H7_SPI_SR_RXP;
1058 
1059 	if (!(sr & mask)) {
1060 		dev_warn(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
1061 			 sr, ier);
1062 		spin_unlock_irqrestore(&spi->lock, flags);
1063 		return IRQ_NONE;
1064 	}
1065 
1066 	if (sr & STM32H7_SPI_SR_SUSP) {
1067 		static DEFINE_RATELIMIT_STATE(rs,
1068 					      DEFAULT_RATELIMIT_INTERVAL * 10,
1069 					      1);
1070 		ratelimit_set_flags(&rs, RATELIMIT_MSG_ON_RELEASE);
1071 		if (__ratelimit(&rs))
1072 			dev_dbg_ratelimited(spi->dev, "Communication suspended\n");
1073 		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
1074 			stm32h7_spi_read_rxfifo(spi);
1075 		/*
1076 		 * If communication is suspended while using DMA, it means
1077 		 * that something went wrong, so stop the current transfer
1078 		 */
1079 		if (spi->cur_usedma)
1080 			end = true;
1081 	}
1082 
1083 	if (sr & STM32H7_SPI_SR_MODF) {
1084 		dev_warn(spi->dev, "Mode fault: transfer aborted\n");
1085 		end = true;
1086 	}
1087 
1088 	if (sr & STM32H7_SPI_SR_OVR) {
1089 		dev_err(spi->dev, "Overrun: RX data lost\n");
1090 		end = true;
1091 	}
1092 
1093 	if (sr & STM32H7_SPI_SR_EOT) {
1094 		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
1095 			stm32h7_spi_read_rxfifo(spi);
1096 		if (!spi->cur_usedma ||
1097 		    (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX))
1098 			end = true;
1099 	}
1100 
1101 	if (sr & STM32H7_SPI_SR_TXP)
1102 		if (!spi->cur_usedma && (spi->tx_buf && (spi->tx_len > 0)))
1103 			stm32h7_spi_write_txfifo(spi);
1104 
1105 	if (sr & STM32H7_SPI_SR_RXP)
1106 		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
1107 			stm32h7_spi_read_rxfifo(spi);
1108 
1109 	writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR);
1110 
1111 	spin_unlock_irqrestore(&spi->lock, flags);
1112 
1113 	if (end) {
1114 		stm32h7_spi_disable(spi);
1115 		spi_finalize_current_transfer(ctrl);
1116 	}
1117 
1118 	return IRQ_HANDLED;
1119 }
1120 
1121 static int stm32_spi_optimize_message(struct spi_message *msg)
1122 {
1123 	struct spi_controller *ctrl = msg->spi->controller;
1124 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1125 
1126 	/* On STM32H7, messages should not exceed a maximum size set
1127 	 * later via the set_number_of_data function. In order to
1128 	 * ensure that, split large messages into several messages
1129 	 */
1130 	if (spi->cfg->set_number_of_data)
1131 		return spi_split_transfers_maxwords(ctrl, msg, spi->t_size_max);
1132 
1133 	return 0;
1134 }
1135 
1136 /**
1137  * stm32_spi_prepare_msg - set up the controller to transfer a single message
1138  * @ctrl: controller interface
1139  * @msg: pointer to spi message
1140  */
1141 static int stm32_spi_prepare_msg(struct spi_controller *ctrl,
1142 				 struct spi_message *msg)
1143 {
1144 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1145 	struct spi_device *spi_dev = msg->spi;
1146 	struct device_node *np = spi_dev->dev.of_node;
1147 	unsigned long flags;
1148 	u32 clrb = 0, setb = 0;
1149 
1150 	/* SPI target device may need time between data frames */
1151 	spi->cur_midi = 0;
1152 	if (np && !of_property_read_u32(np, "st,spi-midi-ns", &spi->cur_midi))
1153 		dev_dbg(spi->dev, "%dns inter-data idleness\n", spi->cur_midi);
1154 
1155 	if (spi_dev->mode & SPI_CPOL)
1156 		setb |= spi->cfg->regs->cpol.mask;
1157 	else
1158 		clrb |= spi->cfg->regs->cpol.mask;
1159 
1160 	if (spi_dev->mode & SPI_CPHA)
1161 		setb |= spi->cfg->regs->cpha.mask;
1162 	else
1163 		clrb |= spi->cfg->regs->cpha.mask;
1164 
1165 	if (spi_dev->mode & SPI_LSB_FIRST)
1166 		setb |= spi->cfg->regs->lsb_first.mask;
1167 	else
1168 		clrb |= spi->cfg->regs->lsb_first.mask;
1169 
1170 	if (STM32_SPI_DEVICE_MODE(spi) && spi_dev->mode & SPI_CS_HIGH)
1171 		setb |= spi->cfg->regs->cs_high.mask;
1172 	else
1173 		clrb |= spi->cfg->regs->cs_high.mask;
1174 
1175 	dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n",
1176 		!!(spi_dev->mode & SPI_CPOL),
1177 		!!(spi_dev->mode & SPI_CPHA),
1178 		!!(spi_dev->mode & SPI_LSB_FIRST),
1179 		!!(spi_dev->mode & SPI_CS_HIGH));
1180 
1181 	spin_lock_irqsave(&spi->lock, flags);
1182 
1183 	/* CPOL, CPHA and LSB FIRST bits have common register */
1184 	if (clrb || setb)
1185 		writel_relaxed(
1186 			(readl_relaxed(spi->base + spi->cfg->regs->cpol.reg) &
1187 			 ~clrb) | setb,
1188 			spi->base + spi->cfg->regs->cpol.reg);
1189 
1190 	spin_unlock_irqrestore(&spi->lock, flags);
1191 
1192 	return 0;
1193 }
1194 
1195 /**
1196  * stm32fx_spi_dma_tx_cb - dma callback
1197  * @data: pointer to the spi controller data structure
1198  *
1199  * DMA callback is called when the transfer is complete for DMA TX channel.
1200  */
1201 static void stm32fx_spi_dma_tx_cb(void *data)
1202 {
1203 	struct stm32_spi *spi = data;
1204 
1205 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
1206 		spi_finalize_current_transfer(spi->ctrl);
1207 		stm32fx_spi_disable(spi);
1208 	}
1209 }
1210 
1211 /**
1212  * stm32_spi_dma_rx_cb - dma callback
1213  * @data: pointer to the spi controller data structure
1214  *
1215  * DMA callback is called when the transfer is complete for DMA RX channel.
1216  */
1217 static void stm32_spi_dma_rx_cb(void *data)
1218 {
1219 	struct stm32_spi *spi = data;
1220 
1221 	spi_finalize_current_transfer(spi->ctrl);
1222 	spi->cfg->disable(spi);
1223 }
1224 
1225 /**
1226  * stm32_spi_dma_config - configure dma slave channel depending on current
1227  *			  transfer bits_per_word.
1228  * @spi: pointer to the spi controller data structure
1229  * @dma_chan: pointer to the DMA channel
1230  * @dma_conf: pointer to the dma_slave_config structure
1231  * @dir: direction of the dma transfer
1232  */
1233 static void stm32_spi_dma_config(struct stm32_spi *spi,
1234 				 struct dma_chan *dma_chan,
1235 				 struct dma_slave_config *dma_conf,
1236 				 enum dma_transfer_direction dir)
1237 {
1238 	enum dma_slave_buswidth buswidth;
1239 	struct dma_slave_caps caps;
1240 	u32 maxburst = 1;
1241 	int ret;
1242 
1243 	if (spi->cur_bpw <= 8)
1244 		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
1245 	else if (spi->cur_bpw <= 16)
1246 		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
1247 	else
1248 		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
1249 
1250 	/* Valid for DMA Half or Full Fifo threshold */
1251 	if (!spi->cfg->prevent_dma_burst && spi->cfg->has_fifo && spi->cur_fthlv != 2)
1252 		maxburst = spi->cur_fthlv;
1253 
1254 	/* Get the DMA channel caps, and adjust maxburst if possible */
1255 	ret = dma_get_slave_caps(dma_chan, &caps);
1256 	if (!ret)
1257 		maxburst = min(maxburst, caps.max_burst);
1258 
1259 	memset(dma_conf, 0, sizeof(struct dma_slave_config));
1260 	dma_conf->direction = dir;
1261 	if (dma_conf->direction == DMA_DEV_TO_MEM) { /* RX */
1262 		dma_conf->src_addr = spi->phys_addr + spi->cfg->regs->rx.reg;
1263 		dma_conf->src_addr_width = buswidth;
1264 		dma_conf->src_maxburst = maxburst;
1265 
1266 		dev_dbg(spi->dev, "Rx DMA config buswidth=%d, maxburst=%d\n",
1267 			buswidth, maxburst);
1268 	} else if (dma_conf->direction == DMA_MEM_TO_DEV) { /* TX */
1269 		dma_conf->dst_addr = spi->phys_addr + spi->cfg->regs->tx.reg;
1270 		dma_conf->dst_addr_width = buswidth;
1271 		dma_conf->dst_maxburst = maxburst;
1272 
1273 		dev_dbg(spi->dev, "Tx DMA config buswidth=%d, maxburst=%d\n",
1274 			buswidth, maxburst);
1275 	}
1276 }
1277 
1278 /**
1279  * stm32fx_spi_transfer_one_irq - transfer a single spi_transfer using
1280  *				  interrupts
1281  * @spi: pointer to the spi controller data structure
1282  *
1283  * It must returns 0 if the transfer is finished or 1 if the transfer is still
1284  * in progress.
1285  */
1286 static int stm32fx_spi_transfer_one_irq(struct stm32_spi *spi)
1287 {
1288 	unsigned long flags;
1289 	u32 cr2 = 0;
1290 
1291 	/* Enable the interrupts relative to the current communication mode */
1292 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
1293 		cr2 |= STM32FX_SPI_CR2_TXEIE;
1294 	} else if (spi->cur_comm == SPI_FULL_DUPLEX ||
1295 				spi->cur_comm == SPI_SIMPLEX_RX ||
1296 				spi->cur_comm == SPI_3WIRE_RX) {
1297 		/* In transmit-only mode, the OVR flag is set in the SR register
1298 		 * since the received data are never read. Therefore set OVR
1299 		 * interrupt only when rx buffer is available.
1300 		 */
1301 		cr2 |= STM32FX_SPI_CR2_RXNEIE | STM32FX_SPI_CR2_ERRIE;
1302 	} else {
1303 		return -EINVAL;
1304 	}
1305 
1306 	spin_lock_irqsave(&spi->lock, flags);
1307 
1308 	stm32_spi_set_bits(spi, STM32FX_SPI_CR2, cr2);
1309 
1310 	stm32_spi_enable(spi);
1311 
1312 	/* starting data transfer when buffer is loaded */
1313 	if (spi->tx_buf)
1314 		spi->cfg->write_tx(spi);
1315 
1316 	spin_unlock_irqrestore(&spi->lock, flags);
1317 
1318 	return 1;
1319 }
1320 
1321 /**
1322  * stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using
1323  *				  interrupts
1324  * @spi: pointer to the spi controller data structure
1325  *
1326  * It must returns 0 if the transfer is finished or 1 if the transfer is still
1327  * in progress.
1328  */
1329 static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi)
1330 {
1331 	unsigned long flags;
1332 	u32 ier = 0;
1333 
1334 	/* Enable the interrupts relative to the current communication mode */
1335 	if (spi->tx_buf && spi->rx_buf)	/* Full Duplex */
1336 		ier |= STM32H7_SPI_IER_DXPIE;
1337 	else if (spi->tx_buf)		/* Half-Duplex TX dir or Simplex TX */
1338 		ier |= STM32H7_SPI_IER_TXPIE;
1339 	else if (spi->rx_buf)		/* Half-Duplex RX dir or Simplex RX */
1340 		ier |= STM32H7_SPI_IER_RXPIE;
1341 
1342 	/* Enable the interrupts relative to the end of transfer */
1343 	ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE |
1344 	       STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
1345 
1346 	spin_lock_irqsave(&spi->lock, flags);
1347 
1348 	stm32_spi_enable(spi);
1349 
1350 	/* Be sure to have data in fifo before starting data transfer */
1351 	if (spi->tx_buf)
1352 		stm32h7_spi_write_txfifo(spi);
1353 
1354 	if (STM32_SPI_HOST_MODE(spi))
1355 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
1356 
1357 	writel_relaxed(ier, spi->base + STM32H7_SPI_IER);
1358 
1359 	spin_unlock_irqrestore(&spi->lock, flags);
1360 
1361 	return 1;
1362 }
1363 
1364 /**
1365  * stm32fx_spi_transfer_one_dma_start - Set SPI driver registers to start
1366  *					transfer using DMA
1367  * @spi: pointer to the spi controller data structure
1368  */
1369 static void stm32fx_spi_transfer_one_dma_start(struct stm32_spi *spi)
1370 {
1371 	/* In DMA mode end of transfer is handled by DMA TX or RX callback. */
1372 	if (spi->cur_comm == SPI_SIMPLEX_RX || spi->cur_comm == SPI_3WIRE_RX ||
1373 	    spi->cur_comm == SPI_FULL_DUPLEX) {
1374 		/*
1375 		 * In transmit-only mode, the OVR flag is set in the SR register
1376 		 * since the received data are never read. Therefore set OVR
1377 		 * interrupt only when rx buffer is available.
1378 		 */
1379 		stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_ERRIE);
1380 	}
1381 
1382 	stm32_spi_enable(spi);
1383 }
1384 
1385 /**
1386  * stm32f7_spi_transfer_one_dma_start - Set SPI driver registers to start
1387  *					transfer using DMA
1388  * @spi: pointer to the spi controller data structure
1389  */
1390 static void stm32f7_spi_transfer_one_dma_start(struct stm32_spi *spi)
1391 {
1392 	/* Configure DMA request trigger threshold according to DMA width */
1393 	if (spi->cur_bpw <= 8)
1394 		stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
1395 	else
1396 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
1397 
1398 	stm32fx_spi_transfer_one_dma_start(spi);
1399 }
1400 
1401 /**
1402  * stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start
1403  *					transfer using DMA
1404  * @spi: pointer to the spi controller data structure
1405  */
1406 static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
1407 {
1408 	uint32_t ier = STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
1409 
1410 	/* Enable the interrupts */
1411 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX)
1412 		ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE;
1413 
1414 	stm32_spi_set_bits(spi, STM32H7_SPI_IER, ier);
1415 
1416 	stm32_spi_enable(spi);
1417 
1418 	if (STM32_SPI_HOST_MODE(spi))
1419 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
1420 }
1421 
1422 /**
1423  * stm32_spi_transfer_one_dma - transfer a single spi_transfer using DMA
1424  * @spi: pointer to the spi controller data structure
1425  * @xfer: pointer to the spi_transfer structure
1426  *
1427  * It must returns 0 if the transfer is finished or 1 if the transfer is still
1428  * in progress.
1429  */
1430 static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
1431 				      struct spi_transfer *xfer)
1432 {
1433 	struct dma_slave_config tx_dma_conf, rx_dma_conf;
1434 	struct dma_async_tx_descriptor *tx_dma_desc, *rx_dma_desc;
1435 	unsigned long flags;
1436 
1437 	spin_lock_irqsave(&spi->lock, flags);
1438 
1439 	rx_dma_desc = NULL;
1440 	if (spi->rx_buf && spi->dma_rx) {
1441 		stm32_spi_dma_config(spi, spi->dma_rx, &rx_dma_conf, DMA_DEV_TO_MEM);
1442 		dmaengine_slave_config(spi->dma_rx, &rx_dma_conf);
1443 
1444 		/* Enable Rx DMA request */
1445 		stm32_spi_set_bits(spi, spi->cfg->regs->dma_rx_en.reg,
1446 				   spi->cfg->regs->dma_rx_en.mask);
1447 
1448 		rx_dma_desc = dmaengine_prep_slave_sg(
1449 					spi->dma_rx, xfer->rx_sg.sgl,
1450 					xfer->rx_sg.nents,
1451 					rx_dma_conf.direction,
1452 					DMA_PREP_INTERRUPT);
1453 	}
1454 
1455 	tx_dma_desc = NULL;
1456 	if (spi->tx_buf && spi->dma_tx) {
1457 		stm32_spi_dma_config(spi, spi->dma_tx, &tx_dma_conf, DMA_MEM_TO_DEV);
1458 		dmaengine_slave_config(spi->dma_tx, &tx_dma_conf);
1459 
1460 		tx_dma_desc = dmaengine_prep_slave_sg(
1461 					spi->dma_tx, xfer->tx_sg.sgl,
1462 					xfer->tx_sg.nents,
1463 					tx_dma_conf.direction,
1464 					DMA_PREP_INTERRUPT);
1465 	}
1466 
1467 	if ((spi->tx_buf && spi->dma_tx && !tx_dma_desc) ||
1468 	    (spi->rx_buf && spi->dma_rx && !rx_dma_desc))
1469 		goto dma_desc_error;
1470 
1471 	if (spi->cur_comm == SPI_FULL_DUPLEX && (!tx_dma_desc || !rx_dma_desc))
1472 		goto dma_desc_error;
1473 
1474 	if (rx_dma_desc) {
1475 		rx_dma_desc->callback = spi->cfg->dma_rx_cb;
1476 		rx_dma_desc->callback_param = spi;
1477 
1478 		if (dma_submit_error(dmaengine_submit(rx_dma_desc))) {
1479 			dev_err(spi->dev, "Rx DMA submit failed\n");
1480 			goto dma_desc_error;
1481 		}
1482 		/* Enable Rx DMA channel */
1483 		dma_async_issue_pending(spi->dma_rx);
1484 	}
1485 
1486 	if (tx_dma_desc) {
1487 		if (spi->cur_comm == SPI_SIMPLEX_TX ||
1488 		    spi->cur_comm == SPI_3WIRE_TX) {
1489 			tx_dma_desc->callback = spi->cfg->dma_tx_cb;
1490 			tx_dma_desc->callback_param = spi;
1491 		}
1492 
1493 		if (dma_submit_error(dmaengine_submit(tx_dma_desc))) {
1494 			dev_err(spi->dev, "Tx DMA submit failed\n");
1495 			goto dma_submit_error;
1496 		}
1497 		/* Enable Tx DMA channel */
1498 		dma_async_issue_pending(spi->dma_tx);
1499 
1500 		/* Enable Tx DMA request */
1501 		stm32_spi_set_bits(spi, spi->cfg->regs->dma_tx_en.reg,
1502 				   spi->cfg->regs->dma_tx_en.mask);
1503 	}
1504 
1505 	spi->cfg->transfer_one_dma_start(spi);
1506 
1507 	spin_unlock_irqrestore(&spi->lock, flags);
1508 
1509 	return 1;
1510 
1511 dma_submit_error:
1512 	if (spi->dma_rx)
1513 		dmaengine_terminate_sync(spi->dma_rx);
1514 
1515 dma_desc_error:
1516 	stm32_spi_clr_bits(spi, spi->cfg->regs->dma_rx_en.reg,
1517 			   spi->cfg->regs->dma_rx_en.mask);
1518 
1519 	spin_unlock_irqrestore(&spi->lock, flags);
1520 
1521 	dev_info(spi->dev, "DMA issue: fall back to irq transfer\n");
1522 
1523 	spi->cur_usedma = false;
1524 	return spi->cfg->transfer_one_irq(spi);
1525 }
1526 
1527 /**
1528  * stm32f4_spi_set_bpw - Configure bits per word
1529  * @spi: pointer to the spi controller data structure
1530  */
1531 static void stm32f4_spi_set_bpw(struct stm32_spi *spi)
1532 {
1533 	if (spi->cur_bpw == 16)
1534 		stm32_spi_set_bits(spi, STM32FX_SPI_CR1, STM32F4_SPI_CR1_DFF);
1535 	else
1536 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR1, STM32F4_SPI_CR1_DFF);
1537 }
1538 
1539 /**
1540  * stm32f7_spi_set_bpw - Configure bits per word
1541  * @spi: pointer to the spi controller data structure
1542  */
1543 static void stm32f7_spi_set_bpw(struct stm32_spi *spi)
1544 {
1545 	u32 bpw;
1546 	u32 cr2_clrb = 0, cr2_setb = 0;
1547 
1548 	bpw = spi->cur_bpw - 1;
1549 
1550 	cr2_clrb |= STM32F7_SPI_CR2_DS;
1551 	cr2_setb |= FIELD_PREP(STM32F7_SPI_CR2_DS, bpw);
1552 
1553 	if (spi->rx_len >= sizeof(u16))
1554 		cr2_clrb |= STM32F7_SPI_CR2_FRXTH;
1555 	else
1556 		cr2_setb |= STM32F7_SPI_CR2_FRXTH;
1557 
1558 	writel_relaxed(
1559 		(readl_relaxed(spi->base + STM32FX_SPI_CR2) &
1560 		 ~cr2_clrb) | cr2_setb,
1561 		spi->base + STM32FX_SPI_CR2);
1562 }
1563 
1564 /**
1565  * stm32h7_spi_set_bpw - configure bits per word
1566  * @spi: pointer to the spi controller data structure
1567  */
1568 static void stm32h7_spi_set_bpw(struct stm32_spi *spi)
1569 {
1570 	u32 bpw, fthlv;
1571 	u32 cfg1_clrb = 0, cfg1_setb = 0;
1572 
1573 	bpw = spi->cur_bpw - 1;
1574 
1575 	cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE;
1576 	cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_DSIZE, bpw);
1577 
1578 	spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen);
1579 	fthlv = spi->cur_fthlv - 1;
1580 
1581 	cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
1582 	cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_FTHLV, fthlv);
1583 
1584 	writel_relaxed(
1585 		(readl_relaxed(spi->base + STM32H7_SPI_CFG1) &
1586 		 ~cfg1_clrb) | cfg1_setb,
1587 		spi->base + STM32H7_SPI_CFG1);
1588 }
1589 
1590 /**
1591  * stm32_spi_set_mbr - Configure baud rate divisor in host mode
1592  * @spi: pointer to the spi controller data structure
1593  * @mbrdiv: baud rate divisor value
1594  */
1595 static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv)
1596 {
1597 	u32 clrb = 0, setb = 0;
1598 
1599 	clrb |= spi->cfg->regs->br.mask;
1600 	setb |= (mbrdiv << spi->cfg->regs->br.shift) & spi->cfg->regs->br.mask;
1601 
1602 	writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) &
1603 			~clrb) | setb,
1604 		       spi->base + spi->cfg->regs->br.reg);
1605 }
1606 
1607 /**
1608  * stm32_spi_communication_type - return transfer communication type
1609  * @spi_dev: pointer to the spi device
1610  * @transfer: pointer to spi transfer
1611  */
1612 static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev,
1613 						 struct spi_transfer *transfer)
1614 {
1615 	unsigned int type = SPI_FULL_DUPLEX;
1616 
1617 	if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */
1618 		/*
1619 		 * SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL
1620 		 * is forbidden and unvalidated by SPI subsystem so depending
1621 		 * on the valid buffer, we can determine the direction of the
1622 		 * transfer.
1623 		 */
1624 		if (!transfer->tx_buf)
1625 			type = SPI_3WIRE_RX;
1626 		else
1627 			type = SPI_3WIRE_TX;
1628 	} else {
1629 		if (!transfer->tx_buf)
1630 			type = SPI_SIMPLEX_RX;
1631 		else if (!transfer->rx_buf)
1632 			type = SPI_SIMPLEX_TX;
1633 	}
1634 
1635 	return type;
1636 }
1637 
1638 /**
1639  * stm32fx_spi_set_mode - configure communication mode
1640  * @spi: pointer to the spi controller data structure
1641  * @comm_type: type of communication to configure
1642  */
1643 static int stm32fx_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
1644 {
1645 	if (comm_type == SPI_3WIRE_TX || comm_type == SPI_SIMPLEX_TX) {
1646 		stm32_spi_set_bits(spi, STM32FX_SPI_CR1,
1647 					STM32FX_SPI_CR1_BIDIMODE |
1648 					STM32FX_SPI_CR1_BIDIOE);
1649 	} else if (comm_type == SPI_FULL_DUPLEX ||
1650 				comm_type == SPI_SIMPLEX_RX) {
1651 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR1,
1652 					STM32FX_SPI_CR1_BIDIMODE |
1653 					STM32FX_SPI_CR1_BIDIOE);
1654 	} else if (comm_type == SPI_3WIRE_RX) {
1655 		stm32_spi_set_bits(spi, STM32FX_SPI_CR1,
1656 					STM32FX_SPI_CR1_BIDIMODE);
1657 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR1,
1658 					STM32FX_SPI_CR1_BIDIOE);
1659 	} else {
1660 		return -EINVAL;
1661 	}
1662 
1663 	return 0;
1664 }
1665 
1666 /**
1667  * stm32h7_spi_set_mode - configure communication mode
1668  * @spi: pointer to the spi controller data structure
1669  * @comm_type: type of communication to configure
1670  */
1671 static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
1672 {
1673 	u32 mode;
1674 	u32 cfg2_clrb = 0, cfg2_setb = 0;
1675 
1676 	if (comm_type == SPI_3WIRE_RX) {
1677 		mode = STM32H7_SPI_HALF_DUPLEX;
1678 		stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
1679 	} else if (comm_type == SPI_3WIRE_TX) {
1680 		mode = STM32H7_SPI_HALF_DUPLEX;
1681 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
1682 	} else if (comm_type == SPI_SIMPLEX_RX) {
1683 		mode = STM32H7_SPI_SIMPLEX_RX;
1684 	} else if (comm_type == SPI_SIMPLEX_TX) {
1685 		mode = STM32H7_SPI_SIMPLEX_TX;
1686 	} else {
1687 		mode = STM32H7_SPI_FULL_DUPLEX;
1688 	}
1689 
1690 	cfg2_clrb |= STM32H7_SPI_CFG2_COMM;
1691 	cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_COMM, mode);
1692 
1693 	writel_relaxed(
1694 		(readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
1695 		 ~cfg2_clrb) | cfg2_setb,
1696 		spi->base + STM32H7_SPI_CFG2);
1697 
1698 	return 0;
1699 }
1700 
1701 /**
1702  * stm32h7_spi_data_idleness - configure minimum time delay inserted between two
1703  *			       consecutive data frames in host mode
1704  * @spi: pointer to the spi controller data structure
1705  * @len: transfer len
1706  */
1707 static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len)
1708 {
1709 	u32 cfg2_clrb = 0, cfg2_setb = 0;
1710 
1711 	cfg2_clrb |= STM32H7_SPI_CFG2_MIDI;
1712 	if ((len > 1) && (spi->cur_midi > 0)) {
1713 		u32 sck_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, spi->cur_speed);
1714 		u32 midi = min_t(u32,
1715 				 DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
1716 				 FIELD_GET(STM32H7_SPI_CFG2_MIDI,
1717 				 STM32H7_SPI_CFG2_MIDI));
1718 
1719 
1720 		dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n",
1721 			sck_period_ns, midi, midi * sck_period_ns);
1722 		cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_MIDI, midi);
1723 	}
1724 
1725 	writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
1726 			~cfg2_clrb) | cfg2_setb,
1727 		       spi->base + STM32H7_SPI_CFG2);
1728 }
1729 
1730 /**
1731  * stm32h7_spi_number_of_data - configure number of data at current transfer
1732  * @spi: pointer to the spi controller data structure
1733  * @nb_words: transfer length (in words)
1734  */
1735 static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words)
1736 {
1737 	if (nb_words <= spi->t_size_max) {
1738 		writel_relaxed(FIELD_PREP(STM32H7_SPI_CR2_TSIZE, nb_words),
1739 			       spi->base + STM32H7_SPI_CR2);
1740 	} else {
1741 		return -EMSGSIZE;
1742 	}
1743 
1744 	return 0;
1745 }
1746 
1747 /**
1748  * stm32_spi_transfer_one_setup - common setup to transfer a single
1749  *				  spi_transfer either using DMA or
1750  *				  interrupts.
1751  * @spi: pointer to the spi controller data structure
1752  * @spi_dev: pointer to the spi device
1753  * @transfer: pointer to spi transfer
1754  */
1755 static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
1756 					struct spi_device *spi_dev,
1757 					struct spi_transfer *transfer)
1758 {
1759 	unsigned long flags;
1760 	unsigned int comm_type;
1761 	int nb_words, ret = 0;
1762 	int mbr;
1763 
1764 	spin_lock_irqsave(&spi->lock, flags);
1765 
1766 	spi->cur_xferlen = transfer->len;
1767 
1768 	spi->cur_bpw = transfer->bits_per_word;
1769 	spi->cfg->set_bpw(spi);
1770 
1771 	/* Update spi->cur_speed with real clock speed */
1772 	if (STM32_SPI_HOST_MODE(spi)) {
1773 		mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
1774 					    spi->cfg->baud_rate_div_min,
1775 					    spi->cfg->baud_rate_div_max);
1776 		if (mbr < 0) {
1777 			ret = mbr;
1778 			goto out;
1779 		}
1780 
1781 		transfer->speed_hz = spi->cur_speed;
1782 		stm32_spi_set_mbr(spi, mbr);
1783 	}
1784 
1785 	comm_type = stm32_spi_communication_type(spi_dev, transfer);
1786 	ret = spi->cfg->set_mode(spi, comm_type);
1787 	if (ret < 0)
1788 		goto out;
1789 
1790 	spi->cur_comm = comm_type;
1791 
1792 	if (STM32_SPI_HOST_MODE(spi) && spi->cfg->set_data_idleness)
1793 		spi->cfg->set_data_idleness(spi, transfer->len);
1794 
1795 	if (spi->cur_bpw <= 8)
1796 		nb_words = transfer->len;
1797 	else if (spi->cur_bpw <= 16)
1798 		nb_words = DIV_ROUND_UP(transfer->len * 8, 16);
1799 	else
1800 		nb_words = DIV_ROUND_UP(transfer->len * 8, 32);
1801 
1802 	if (spi->cfg->set_number_of_data) {
1803 		ret = spi->cfg->set_number_of_data(spi, nb_words);
1804 		if (ret < 0)
1805 			goto out;
1806 	}
1807 
1808 	dev_dbg(spi->dev, "transfer communication mode set to %d\n",
1809 		spi->cur_comm);
1810 	dev_dbg(spi->dev,
1811 		"data frame of %d-bit, data packet of %d data frames\n",
1812 		spi->cur_bpw, spi->cur_fthlv);
1813 	if (STM32_SPI_HOST_MODE(spi))
1814 		dev_dbg(spi->dev, "speed set to %dHz\n", spi->cur_speed);
1815 	dev_dbg(spi->dev, "transfer of %d bytes (%d data frames)\n",
1816 		spi->cur_xferlen, nb_words);
1817 	dev_dbg(spi->dev, "dma %s\n",
1818 		(spi->cur_usedma) ? "enabled" : "disabled");
1819 
1820 out:
1821 	spin_unlock_irqrestore(&spi->lock, flags);
1822 
1823 	return ret;
1824 }
1825 
1826 /**
1827  * stm32_spi_transfer_one - transfer a single spi_transfer
1828  * @ctrl: controller interface
1829  * @spi_dev: pointer to the spi device
1830  * @transfer: pointer to spi transfer
1831  *
1832  * It must return 0 if the transfer is finished or 1 if the transfer is still
1833  * in progress.
1834  */
1835 static int stm32_spi_transfer_one(struct spi_controller *ctrl,
1836 				  struct spi_device *spi_dev,
1837 				  struct spi_transfer *transfer)
1838 {
1839 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1840 	int ret;
1841 
1842 	spi->tx_buf = transfer->tx_buf;
1843 	spi->rx_buf = transfer->rx_buf;
1844 	spi->tx_len = spi->tx_buf ? transfer->len : 0;
1845 	spi->rx_len = spi->rx_buf ? transfer->len : 0;
1846 
1847 	spi->cur_usedma = (ctrl->can_dma &&
1848 			   ctrl->can_dma(ctrl, spi_dev, transfer));
1849 
1850 	ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer);
1851 	if (ret) {
1852 		dev_err(spi->dev, "SPI transfer setup failed\n");
1853 		return ret;
1854 	}
1855 
1856 	if (spi->cur_usedma)
1857 		return stm32_spi_transfer_one_dma(spi, transfer);
1858 	else
1859 		return spi->cfg->transfer_one_irq(spi);
1860 }
1861 
1862 /**
1863  * stm32_spi_unprepare_msg - relax the hardware
1864  * @ctrl: controller interface
1865  * @msg: pointer to the spi message
1866  */
1867 static int stm32_spi_unprepare_msg(struct spi_controller *ctrl,
1868 				   struct spi_message *msg)
1869 {
1870 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1871 
1872 	spi->cfg->disable(spi);
1873 
1874 	return 0;
1875 }
1876 
1877 /**
1878  * stm32fx_spi_config - Configure SPI controller as SPI host
1879  * @spi: pointer to the spi controller data structure
1880  */
1881 static int stm32fx_spi_config(struct stm32_spi *spi)
1882 {
1883 	unsigned long flags;
1884 
1885 	spin_lock_irqsave(&spi->lock, flags);
1886 
1887 	/* Ensure I2SMOD bit is kept cleared */
1888 	stm32_spi_clr_bits(spi, STM32FX_SPI_I2SCFGR,
1889 			   STM32FX_SPI_I2SCFGR_I2SMOD);
1890 
1891 	/*
1892 	 * - SS input value high
1893 	 * - transmitter half duplex direction
1894 	 * - Set the host mode (default Motorola mode)
1895 	 * - Consider 1 host/n targets configuration and
1896 	 *   SS input value is determined by the SSI bit
1897 	 */
1898 	stm32_spi_set_bits(spi, STM32FX_SPI_CR1, STM32FX_SPI_CR1_SSI |
1899 						 STM32FX_SPI_CR1_BIDIOE |
1900 						 STM32FX_SPI_CR1_MSTR |
1901 						 STM32FX_SPI_CR1_SSM);
1902 
1903 	spin_unlock_irqrestore(&spi->lock, flags);
1904 
1905 	return 0;
1906 }
1907 
1908 /**
1909  * stm32h7_spi_config - Configure SPI controller
1910  * @spi: pointer to the spi controller data structure
1911  */
1912 static int stm32h7_spi_config(struct stm32_spi *spi)
1913 {
1914 	unsigned long flags;
1915 	u32 cr1 = 0, cfg2 = 0;
1916 
1917 	spin_lock_irqsave(&spi->lock, flags);
1918 
1919 	/* Ensure I2SMOD bit is kept cleared */
1920 	stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR,
1921 			   STM32H7_SPI_I2SCFGR_I2SMOD);
1922 
1923 	if (STM32_SPI_DEVICE_MODE(spi)) {
1924 		/* Use native device select */
1925 		cfg2 &= ~STM32H7_SPI_CFG2_SSM;
1926 	} else {
1927 		/*
1928 		 * - Transmitter half duplex direction
1929 		 * - Automatic communication suspend when RX-Fifo is full
1930 		 * - SS input value high
1931 		 */
1932 		cr1 |= STM32H7_SPI_CR1_HDDIR | STM32H7_SPI_CR1_MASRX | STM32H7_SPI_CR1_SSI;
1933 
1934 		/*
1935 		 * - Set the host mode (default Motorola mode)
1936 		 * - Consider 1 host/n devices configuration and
1937 		 *   SS input value is determined by the SSI bit
1938 		 * - keep control of all associated GPIOs
1939 		 */
1940 		cfg2 |= STM32H7_SPI_CFG2_MASTER | STM32H7_SPI_CFG2_SSM | STM32H7_SPI_CFG2_AFCNTR;
1941 	}
1942 
1943 	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, cr1);
1944 	stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, cfg2);
1945 
1946 	spin_unlock_irqrestore(&spi->lock, flags);
1947 
1948 	return 0;
1949 }
1950 
1951 static const struct stm32_spi_cfg stm32f4_spi_cfg = {
1952 	.regs = &stm32fx_spi_regspec,
1953 	.get_bpw_mask = stm32f4_spi_get_bpw_mask,
1954 	.disable = stm32fx_spi_disable,
1955 	.config = stm32fx_spi_config,
1956 	.set_bpw = stm32f4_spi_set_bpw,
1957 	.set_mode = stm32fx_spi_set_mode,
1958 	.write_tx = stm32f4_spi_write_tx,
1959 	.read_rx = stm32f4_spi_read_rx,
1960 	.transfer_one_dma_start = stm32fx_spi_transfer_one_dma_start,
1961 	.dma_tx_cb = stm32fx_spi_dma_tx_cb,
1962 	.dma_rx_cb = stm32_spi_dma_rx_cb,
1963 	.transfer_one_irq = stm32fx_spi_transfer_one_irq,
1964 	.irq_handler_event = stm32fx_spi_irq_event,
1965 	.irq_handler_thread = stm32fx_spi_irq_thread,
1966 	.baud_rate_div_min = STM32FX_SPI_BR_DIV_MIN,
1967 	.baud_rate_div_max = STM32FX_SPI_BR_DIV_MAX,
1968 	.has_fifo = false,
1969 	.has_device_mode = false,
1970 	.flags = SPI_CONTROLLER_MUST_TX,
1971 };
1972 
1973 static const struct stm32_spi_cfg stm32f7_spi_cfg = {
1974 	.regs = &stm32fx_spi_regspec,
1975 	.get_bpw_mask = stm32f7_spi_get_bpw_mask,
1976 	.disable = stm32fx_spi_disable,
1977 	.config = stm32fx_spi_config,
1978 	.set_bpw = stm32f7_spi_set_bpw,
1979 	.set_mode = stm32fx_spi_set_mode,
1980 	.write_tx = stm32f7_spi_write_tx,
1981 	.read_rx = stm32f7_spi_read_rx,
1982 	.transfer_one_dma_start = stm32f7_spi_transfer_one_dma_start,
1983 	.dma_tx_cb = stm32fx_spi_dma_tx_cb,
1984 	.dma_rx_cb = stm32_spi_dma_rx_cb,
1985 	.transfer_one_irq = stm32fx_spi_transfer_one_irq,
1986 	.irq_handler_event = stm32fx_spi_irq_event,
1987 	.irq_handler_thread = stm32fx_spi_irq_thread,
1988 	.baud_rate_div_min = STM32FX_SPI_BR_DIV_MIN,
1989 	.baud_rate_div_max = STM32FX_SPI_BR_DIV_MAX,
1990 	.has_fifo = false,
1991 	.flags = SPI_CONTROLLER_MUST_TX,
1992 };
1993 
1994 static const struct stm32_spi_cfg stm32h7_spi_cfg = {
1995 	.regs = &stm32h7_spi_regspec,
1996 	.get_fifo_size = stm32h7_spi_get_fifo_size,
1997 	.get_bpw_mask = stm32h7_spi_get_bpw_mask,
1998 	.disable = stm32h7_spi_disable,
1999 	.config = stm32h7_spi_config,
2000 	.set_bpw = stm32h7_spi_set_bpw,
2001 	.set_mode = stm32h7_spi_set_mode,
2002 	.set_data_idleness = stm32h7_spi_data_idleness,
2003 	.set_number_of_data = stm32h7_spi_number_of_data,
2004 	.write_tx = stm32h7_spi_write_txfifo,
2005 	.read_rx = stm32h7_spi_read_rxfifo,
2006 	.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
2007 	.dma_rx_cb = stm32_spi_dma_rx_cb,
2008 	/*
2009 	 * dma_tx_cb is not necessary since in case of TX, dma is followed by
2010 	 * SPI access hence handling is performed within the SPI interrupt
2011 	 */
2012 	.transfer_one_irq = stm32h7_spi_transfer_one_irq,
2013 	.irq_handler_thread = stm32h7_spi_irq_thread,
2014 	.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
2015 	.baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
2016 	.has_fifo = true,
2017 	.has_device_mode = true,
2018 };
2019 
2020 /*
2021  * STM32MP2 is compatible with the STM32H7 except:
2022  * - enforce the DMA maxburst value to 1
2023  * - spi8 have limited feature set (TSIZE_MAX = 1024, BPW of 8 OR 16)
2024  */
2025 static const struct stm32_spi_cfg stm32mp25_spi_cfg = {
2026 	.regs = &stm32mp25_spi_regspec,
2027 	.get_fifo_size = stm32h7_spi_get_fifo_size,
2028 	.get_bpw_mask = stm32mp25_spi_get_bpw_mask,
2029 	.disable = stm32h7_spi_disable,
2030 	.config = stm32h7_spi_config,
2031 	.set_bpw = stm32h7_spi_set_bpw,
2032 	.set_mode = stm32h7_spi_set_mode,
2033 	.set_data_idleness = stm32h7_spi_data_idleness,
2034 	.set_number_of_data = stm32h7_spi_number_of_data,
2035 	.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
2036 	.dma_rx_cb = stm32_spi_dma_rx_cb,
2037 	/*
2038 	 * dma_tx_cb is not necessary since in case of TX, dma is followed by
2039 	 * SPI access hence handling is performed within the SPI interrupt
2040 	 */
2041 	.transfer_one_irq = stm32h7_spi_transfer_one_irq,
2042 	.irq_handler_thread = stm32h7_spi_irq_thread,
2043 	.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
2044 	.baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
2045 	.has_fifo = true,
2046 	.prevent_dma_burst = true,
2047 };
2048 
2049 static const struct of_device_id stm32_spi_of_match[] = {
2050 	{ .compatible = "st,stm32mp25-spi", .data = (void *)&stm32mp25_spi_cfg },
2051 	{ .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg },
2052 	{ .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg },
2053 	{ .compatible = "st,stm32f7-spi", .data = (void *)&stm32f7_spi_cfg },
2054 	{},
2055 };
2056 MODULE_DEVICE_TABLE(of, stm32_spi_of_match);
2057 
2058 static int stm32h7_spi_device_abort(struct spi_controller *ctrl)
2059 {
2060 	spi_finalize_current_transfer(ctrl);
2061 	return 0;
2062 }
2063 
2064 static int stm32_spi_probe(struct platform_device *pdev)
2065 {
2066 	struct spi_controller *ctrl;
2067 	struct stm32_spi *spi;
2068 	struct resource *res;
2069 	struct reset_control *rst;
2070 	struct device_node *np = pdev->dev.of_node;
2071 	bool device_mode;
2072 	int ret;
2073 	const struct stm32_spi_cfg *cfg = of_device_get_match_data(&pdev->dev);
2074 
2075 	device_mode = of_property_read_bool(np, "spi-slave");
2076 	if (!cfg->has_device_mode && device_mode) {
2077 		dev_err(&pdev->dev, "spi-slave not supported\n");
2078 		return -EPERM;
2079 	}
2080 
2081 	if (device_mode)
2082 		ctrl = devm_spi_alloc_target(&pdev->dev, sizeof(struct stm32_spi));
2083 	else
2084 		ctrl = devm_spi_alloc_host(&pdev->dev, sizeof(struct stm32_spi));
2085 	if (!ctrl) {
2086 		dev_err(&pdev->dev, "spi controller allocation failed\n");
2087 		return -ENOMEM;
2088 	}
2089 	platform_set_drvdata(pdev, ctrl);
2090 
2091 	spi = spi_controller_get_devdata(ctrl);
2092 	spi->dev = &pdev->dev;
2093 	spi->ctrl = ctrl;
2094 	spi->device_mode = device_mode;
2095 	spin_lock_init(&spi->lock);
2096 
2097 	spi->cfg = cfg;
2098 
2099 	spi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2100 	if (IS_ERR(spi->base))
2101 		return PTR_ERR(spi->base);
2102 
2103 	spi->phys_addr = (dma_addr_t)res->start;
2104 
2105 	spi->irq = platform_get_irq(pdev, 0);
2106 	if (spi->irq <= 0)
2107 		return spi->irq;
2108 
2109 	ret = devm_request_threaded_irq(&pdev->dev, spi->irq,
2110 					spi->cfg->irq_handler_event,
2111 					spi->cfg->irq_handler_thread,
2112 					IRQF_ONESHOT, pdev->name, ctrl);
2113 	if (ret) {
2114 		dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq,
2115 			ret);
2116 		return ret;
2117 	}
2118 
2119 	spi->clk = devm_clk_get(&pdev->dev, NULL);
2120 	if (IS_ERR(spi->clk)) {
2121 		ret = PTR_ERR(spi->clk);
2122 		dev_err(&pdev->dev, "clk get failed: %d\n", ret);
2123 		return ret;
2124 	}
2125 
2126 	ret = clk_prepare_enable(spi->clk);
2127 	if (ret) {
2128 		dev_err(&pdev->dev, "clk enable failed: %d\n", ret);
2129 		return ret;
2130 	}
2131 	spi->clk_rate = clk_get_rate(spi->clk);
2132 	if (!spi->clk_rate) {
2133 		dev_err(&pdev->dev, "clk rate = 0\n");
2134 		ret = -EINVAL;
2135 		goto err_clk_disable;
2136 	}
2137 
2138 	rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
2139 	if (rst) {
2140 		if (IS_ERR(rst)) {
2141 			ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
2142 					    "failed to get reset\n");
2143 			goto err_clk_disable;
2144 		}
2145 
2146 		reset_control_assert(rst);
2147 		udelay(2);
2148 		reset_control_deassert(rst);
2149 	}
2150 
2151 	if (spi->cfg->has_fifo)
2152 		spi->fifo_size = spi->cfg->get_fifo_size(spi);
2153 
2154 	spi->feature_set = STM32_SPI_FEATURE_FULL;
2155 	if (spi->cfg->regs->fullcfg.reg) {
2156 		spi->feature_set =
2157 			FIELD_GET(STM32MP25_SPI_HWCFGR1_FULLCFG,
2158 				  readl_relaxed(spi->base + spi->cfg->regs->fullcfg.reg));
2159 
2160 		dev_dbg(spi->dev, "%s feature set\n",
2161 			spi->feature_set == STM32_SPI_FEATURE_FULL ? "full" : "limited");
2162 	}
2163 
2164 	/* Only for STM32H7 and after */
2165 	spi->t_size_max = spi->feature_set == STM32_SPI_FEATURE_FULL ?
2166 				STM32H7_SPI_TSIZE_MAX :
2167 				STM32MP25_SPI_TSIZE_MAX_LIMITED;
2168 	dev_dbg(spi->dev, "one message max size %d\n", spi->t_size_max);
2169 
2170 	ret = spi->cfg->config(spi);
2171 	if (ret) {
2172 		dev_err(&pdev->dev, "controller configuration failed: %d\n",
2173 			ret);
2174 		goto err_clk_disable;
2175 	}
2176 
2177 	ctrl->dev.of_node = pdev->dev.of_node;
2178 	ctrl->auto_runtime_pm = true;
2179 	ctrl->bus_num = pdev->id;
2180 	ctrl->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
2181 			  SPI_3WIRE;
2182 	ctrl->bits_per_word_mask = spi->cfg->get_bpw_mask(spi);
2183 	ctrl->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min;
2184 	ctrl->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max;
2185 	ctrl->use_gpio_descriptors = true;
2186 	ctrl->optimize_message = stm32_spi_optimize_message;
2187 	ctrl->prepare_message = stm32_spi_prepare_msg;
2188 	ctrl->transfer_one = stm32_spi_transfer_one;
2189 	ctrl->unprepare_message = stm32_spi_unprepare_msg;
2190 	ctrl->flags = spi->cfg->flags;
2191 	if (STM32_SPI_DEVICE_MODE(spi))
2192 		ctrl->target_abort = stm32h7_spi_device_abort;
2193 
2194 	spi->dma_tx = dma_request_chan(spi->dev, "tx");
2195 	if (IS_ERR(spi->dma_tx)) {
2196 		ret = PTR_ERR(spi->dma_tx);
2197 		spi->dma_tx = NULL;
2198 		if (ret == -EPROBE_DEFER)
2199 			goto err_clk_disable;
2200 
2201 		dev_warn(&pdev->dev, "failed to request tx dma channel\n");
2202 	} else {
2203 		ctrl->dma_tx = spi->dma_tx;
2204 	}
2205 
2206 	spi->dma_rx = dma_request_chan(spi->dev, "rx");
2207 	if (IS_ERR(spi->dma_rx)) {
2208 		ret = PTR_ERR(spi->dma_rx);
2209 		spi->dma_rx = NULL;
2210 		if (ret == -EPROBE_DEFER)
2211 			goto err_dma_release;
2212 
2213 		dev_warn(&pdev->dev, "failed to request rx dma channel\n");
2214 	} else {
2215 		ctrl->dma_rx = spi->dma_rx;
2216 	}
2217 
2218 	if (spi->dma_tx || spi->dma_rx)
2219 		ctrl->can_dma = stm32_spi_can_dma;
2220 
2221 	pm_runtime_set_autosuspend_delay(&pdev->dev,
2222 					 STM32_SPI_AUTOSUSPEND_DELAY);
2223 	pm_runtime_use_autosuspend(&pdev->dev);
2224 	pm_runtime_set_active(&pdev->dev);
2225 	pm_runtime_get_noresume(&pdev->dev);
2226 	pm_runtime_enable(&pdev->dev);
2227 
2228 	ret = spi_register_controller(ctrl);
2229 	if (ret) {
2230 		dev_err(&pdev->dev, "spi controller registration failed: %d\n",
2231 			ret);
2232 		goto err_pm_disable;
2233 	}
2234 
2235 	pm_runtime_mark_last_busy(&pdev->dev);
2236 	pm_runtime_put_autosuspend(&pdev->dev);
2237 
2238 	dev_info(&pdev->dev, "driver initialized (%s mode)\n",
2239 		 STM32_SPI_HOST_MODE(spi) ? "host" : "device");
2240 
2241 	return 0;
2242 
2243 err_pm_disable:
2244 	pm_runtime_disable(&pdev->dev);
2245 	pm_runtime_put_noidle(&pdev->dev);
2246 	pm_runtime_set_suspended(&pdev->dev);
2247 	pm_runtime_dont_use_autosuspend(&pdev->dev);
2248 err_dma_release:
2249 	if (spi->dma_tx)
2250 		dma_release_channel(spi->dma_tx);
2251 	if (spi->dma_rx)
2252 		dma_release_channel(spi->dma_rx);
2253 err_clk_disable:
2254 	clk_disable_unprepare(spi->clk);
2255 
2256 	return ret;
2257 }
2258 
2259 static void stm32_spi_remove(struct platform_device *pdev)
2260 {
2261 	struct spi_controller *ctrl = platform_get_drvdata(pdev);
2262 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2263 
2264 	pm_runtime_get_sync(&pdev->dev);
2265 
2266 	spi_unregister_controller(ctrl);
2267 	spi->cfg->disable(spi);
2268 
2269 	pm_runtime_disable(&pdev->dev);
2270 	pm_runtime_put_noidle(&pdev->dev);
2271 	pm_runtime_set_suspended(&pdev->dev);
2272 	pm_runtime_dont_use_autosuspend(&pdev->dev);
2273 
2274 	if (ctrl->dma_tx)
2275 		dma_release_channel(ctrl->dma_tx);
2276 	if (ctrl->dma_rx)
2277 		dma_release_channel(ctrl->dma_rx);
2278 
2279 	clk_disable_unprepare(spi->clk);
2280 
2281 
2282 	pinctrl_pm_select_sleep_state(&pdev->dev);
2283 }
2284 
2285 static int __maybe_unused stm32_spi_runtime_suspend(struct device *dev)
2286 {
2287 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2288 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2289 
2290 	clk_disable_unprepare(spi->clk);
2291 
2292 	return pinctrl_pm_select_sleep_state(dev);
2293 }
2294 
2295 static int __maybe_unused stm32_spi_runtime_resume(struct device *dev)
2296 {
2297 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2298 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2299 	int ret;
2300 
2301 	ret = pinctrl_pm_select_default_state(dev);
2302 	if (ret)
2303 		return ret;
2304 
2305 	return clk_prepare_enable(spi->clk);
2306 }
2307 
2308 static int __maybe_unused stm32_spi_suspend(struct device *dev)
2309 {
2310 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2311 	int ret;
2312 
2313 	ret = spi_controller_suspend(ctrl);
2314 	if (ret)
2315 		return ret;
2316 
2317 	return pm_runtime_force_suspend(dev);
2318 }
2319 
2320 static int __maybe_unused stm32_spi_resume(struct device *dev)
2321 {
2322 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2323 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2324 	int ret;
2325 
2326 	ret = pm_runtime_force_resume(dev);
2327 	if (ret)
2328 		return ret;
2329 
2330 	ret = spi_controller_resume(ctrl);
2331 	if (ret) {
2332 		clk_disable_unprepare(spi->clk);
2333 		return ret;
2334 	}
2335 
2336 	ret = pm_runtime_resume_and_get(dev);
2337 	if (ret < 0) {
2338 		dev_err(dev, "Unable to power device:%d\n", ret);
2339 		return ret;
2340 	}
2341 
2342 	spi->cfg->config(spi);
2343 
2344 	pm_runtime_mark_last_busy(dev);
2345 	pm_runtime_put_autosuspend(dev);
2346 
2347 	return 0;
2348 }
2349 
2350 static const struct dev_pm_ops stm32_spi_pm_ops = {
2351 	SET_SYSTEM_SLEEP_PM_OPS(stm32_spi_suspend, stm32_spi_resume)
2352 	SET_RUNTIME_PM_OPS(stm32_spi_runtime_suspend,
2353 			   stm32_spi_runtime_resume, NULL)
2354 };
2355 
2356 static struct platform_driver stm32_spi_driver = {
2357 	.probe = stm32_spi_probe,
2358 	.remove_new = stm32_spi_remove,
2359 	.driver = {
2360 		.name = DRIVER_NAME,
2361 		.pm = &stm32_spi_pm_ops,
2362 		.of_match_table = stm32_spi_of_match,
2363 	},
2364 };
2365 
2366 module_platform_driver(stm32_spi_driver);
2367 
2368 MODULE_ALIAS("platform:" DRIVER_NAME);
2369 MODULE_DESCRIPTION("STMicroelectronics STM32 SPI Controller driver");
2370 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
2371 MODULE_LICENSE("GPL v2");
2372