xref: /linux/drivers/spi/spi-stm32.c (revision 257ca10c7317d4a424e48bb95d14ca53a1f1dd6f)
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 /**
1122  * stm32_spi_prepare_msg - set up the controller to transfer a single message
1123  * @ctrl: controller interface
1124  * @msg: pointer to spi message
1125  */
1126 static int stm32_spi_prepare_msg(struct spi_controller *ctrl,
1127 				 struct spi_message *msg)
1128 {
1129 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1130 	struct spi_device *spi_dev = msg->spi;
1131 	struct device_node *np = spi_dev->dev.of_node;
1132 	unsigned long flags;
1133 	u32 clrb = 0, setb = 0;
1134 
1135 	/* SPI target device may need time between data frames */
1136 	spi->cur_midi = 0;
1137 	if (np && !of_property_read_u32(np, "st,spi-midi-ns", &spi->cur_midi))
1138 		dev_dbg(spi->dev, "%dns inter-data idleness\n", spi->cur_midi);
1139 
1140 	if (spi_dev->mode & SPI_CPOL)
1141 		setb |= spi->cfg->regs->cpol.mask;
1142 	else
1143 		clrb |= spi->cfg->regs->cpol.mask;
1144 
1145 	if (spi_dev->mode & SPI_CPHA)
1146 		setb |= spi->cfg->regs->cpha.mask;
1147 	else
1148 		clrb |= spi->cfg->regs->cpha.mask;
1149 
1150 	if (spi_dev->mode & SPI_LSB_FIRST)
1151 		setb |= spi->cfg->regs->lsb_first.mask;
1152 	else
1153 		clrb |= spi->cfg->regs->lsb_first.mask;
1154 
1155 	if (STM32_SPI_DEVICE_MODE(spi) && spi_dev->mode & SPI_CS_HIGH)
1156 		setb |= spi->cfg->regs->cs_high.mask;
1157 	else
1158 		clrb |= spi->cfg->regs->cs_high.mask;
1159 
1160 	dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n",
1161 		!!(spi_dev->mode & SPI_CPOL),
1162 		!!(spi_dev->mode & SPI_CPHA),
1163 		!!(spi_dev->mode & SPI_LSB_FIRST),
1164 		!!(spi_dev->mode & SPI_CS_HIGH));
1165 
1166 	/* On STM32H7, messages should not exceed a maximum size setted
1167 	 * afterward via the set_number_of_data function. In order to
1168 	 * ensure that, split large messages into several messages
1169 	 */
1170 	if (spi->cfg->set_number_of_data) {
1171 		int ret;
1172 
1173 		ret = spi_split_transfers_maxwords(ctrl, msg,
1174 						   spi->t_size_max,
1175 						   GFP_KERNEL | GFP_DMA);
1176 		if (ret)
1177 			return ret;
1178 	}
1179 
1180 	spin_lock_irqsave(&spi->lock, flags);
1181 
1182 	/* CPOL, CPHA and LSB FIRST bits have common register */
1183 	if (clrb || setb)
1184 		writel_relaxed(
1185 			(readl_relaxed(spi->base + spi->cfg->regs->cpol.reg) &
1186 			 ~clrb) | setb,
1187 			spi->base + spi->cfg->regs->cpol.reg);
1188 
1189 	spin_unlock_irqrestore(&spi->lock, flags);
1190 
1191 	return 0;
1192 }
1193 
1194 /**
1195  * stm32fx_spi_dma_tx_cb - dma callback
1196  * @data: pointer to the spi controller data structure
1197  *
1198  * DMA callback is called when the transfer is complete for DMA TX channel.
1199  */
1200 static void stm32fx_spi_dma_tx_cb(void *data)
1201 {
1202 	struct stm32_spi *spi = data;
1203 
1204 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
1205 		spi_finalize_current_transfer(spi->ctrl);
1206 		stm32fx_spi_disable(spi);
1207 	}
1208 }
1209 
1210 /**
1211  * stm32_spi_dma_rx_cb - dma callback
1212  * @data: pointer to the spi controller data structure
1213  *
1214  * DMA callback is called when the transfer is complete for DMA RX channel.
1215  */
1216 static void stm32_spi_dma_rx_cb(void *data)
1217 {
1218 	struct stm32_spi *spi = data;
1219 
1220 	spi_finalize_current_transfer(spi->ctrl);
1221 	spi->cfg->disable(spi);
1222 }
1223 
1224 /**
1225  * stm32_spi_dma_config - configure dma slave channel depending on current
1226  *			  transfer bits_per_word.
1227  * @spi: pointer to the spi controller data structure
1228  * @dma_chan: pointer to the DMA channel
1229  * @dma_conf: pointer to the dma_slave_config structure
1230  * @dir: direction of the dma transfer
1231  */
1232 static void stm32_spi_dma_config(struct stm32_spi *spi,
1233 				 struct dma_chan *dma_chan,
1234 				 struct dma_slave_config *dma_conf,
1235 				 enum dma_transfer_direction dir)
1236 {
1237 	enum dma_slave_buswidth buswidth;
1238 	struct dma_slave_caps caps;
1239 	u32 maxburst = 1;
1240 	int ret;
1241 
1242 	if (spi->cur_bpw <= 8)
1243 		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
1244 	else if (spi->cur_bpw <= 16)
1245 		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
1246 	else
1247 		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
1248 
1249 	/* Valid for DMA Half or Full Fifo threshold */
1250 	if (!spi->cfg->prevent_dma_burst && spi->cfg->has_fifo && spi->cur_fthlv != 2)
1251 		maxburst = spi->cur_fthlv;
1252 
1253 	/* Get the DMA channel caps, and adjust maxburst if possible */
1254 	ret = dma_get_slave_caps(dma_chan, &caps);
1255 	if (!ret)
1256 		maxburst = min(maxburst, caps.max_burst);
1257 
1258 	memset(dma_conf, 0, sizeof(struct dma_slave_config));
1259 	dma_conf->direction = dir;
1260 	if (dma_conf->direction == DMA_DEV_TO_MEM) { /* RX */
1261 		dma_conf->src_addr = spi->phys_addr + spi->cfg->regs->rx.reg;
1262 		dma_conf->src_addr_width = buswidth;
1263 		dma_conf->src_maxburst = maxburst;
1264 
1265 		dev_dbg(spi->dev, "Rx DMA config buswidth=%d, maxburst=%d\n",
1266 			buswidth, maxburst);
1267 	} else if (dma_conf->direction == DMA_MEM_TO_DEV) { /* TX */
1268 		dma_conf->dst_addr = spi->phys_addr + spi->cfg->regs->tx.reg;
1269 		dma_conf->dst_addr_width = buswidth;
1270 		dma_conf->dst_maxburst = maxburst;
1271 
1272 		dev_dbg(spi->dev, "Tx DMA config buswidth=%d, maxburst=%d\n",
1273 			buswidth, maxburst);
1274 	}
1275 }
1276 
1277 /**
1278  * stm32fx_spi_transfer_one_irq - transfer a single spi_transfer using
1279  *				  interrupts
1280  * @spi: pointer to the spi controller data structure
1281  *
1282  * It must returns 0 if the transfer is finished or 1 if the transfer is still
1283  * in progress.
1284  */
1285 static int stm32fx_spi_transfer_one_irq(struct stm32_spi *spi)
1286 {
1287 	unsigned long flags;
1288 	u32 cr2 = 0;
1289 
1290 	/* Enable the interrupts relative to the current communication mode */
1291 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
1292 		cr2 |= STM32FX_SPI_CR2_TXEIE;
1293 	} else if (spi->cur_comm == SPI_FULL_DUPLEX ||
1294 				spi->cur_comm == SPI_SIMPLEX_RX ||
1295 				spi->cur_comm == SPI_3WIRE_RX) {
1296 		/* In transmit-only mode, the OVR flag is set in the SR register
1297 		 * since the received data are never read. Therefore set OVR
1298 		 * interrupt only when rx buffer is available.
1299 		 */
1300 		cr2 |= STM32FX_SPI_CR2_RXNEIE | STM32FX_SPI_CR2_ERRIE;
1301 	} else {
1302 		return -EINVAL;
1303 	}
1304 
1305 	spin_lock_irqsave(&spi->lock, flags);
1306 
1307 	stm32_spi_set_bits(spi, STM32FX_SPI_CR2, cr2);
1308 
1309 	stm32_spi_enable(spi);
1310 
1311 	/* starting data transfer when buffer is loaded */
1312 	if (spi->tx_buf)
1313 		spi->cfg->write_tx(spi);
1314 
1315 	spin_unlock_irqrestore(&spi->lock, flags);
1316 
1317 	return 1;
1318 }
1319 
1320 /**
1321  * stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using
1322  *				  interrupts
1323  * @spi: pointer to the spi controller data structure
1324  *
1325  * It must returns 0 if the transfer is finished or 1 if the transfer is still
1326  * in progress.
1327  */
1328 static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi)
1329 {
1330 	unsigned long flags;
1331 	u32 ier = 0;
1332 
1333 	/* Enable the interrupts relative to the current communication mode */
1334 	if (spi->tx_buf && spi->rx_buf)	/* Full Duplex */
1335 		ier |= STM32H7_SPI_IER_DXPIE;
1336 	else if (spi->tx_buf)		/* Half-Duplex TX dir or Simplex TX */
1337 		ier |= STM32H7_SPI_IER_TXPIE;
1338 	else if (spi->rx_buf)		/* Half-Duplex RX dir or Simplex RX */
1339 		ier |= STM32H7_SPI_IER_RXPIE;
1340 
1341 	/* Enable the interrupts relative to the end of transfer */
1342 	ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE |
1343 	       STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
1344 
1345 	spin_lock_irqsave(&spi->lock, flags);
1346 
1347 	stm32_spi_enable(spi);
1348 
1349 	/* Be sure to have data in fifo before starting data transfer */
1350 	if (spi->tx_buf)
1351 		stm32h7_spi_write_txfifo(spi);
1352 
1353 	if (STM32_SPI_HOST_MODE(spi))
1354 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
1355 
1356 	writel_relaxed(ier, spi->base + STM32H7_SPI_IER);
1357 
1358 	spin_unlock_irqrestore(&spi->lock, flags);
1359 
1360 	return 1;
1361 }
1362 
1363 /**
1364  * stm32fx_spi_transfer_one_dma_start - Set SPI driver registers to start
1365  *					transfer using DMA
1366  * @spi: pointer to the spi controller data structure
1367  */
1368 static void stm32fx_spi_transfer_one_dma_start(struct stm32_spi *spi)
1369 {
1370 	/* In DMA mode end of transfer is handled by DMA TX or RX callback. */
1371 	if (spi->cur_comm == SPI_SIMPLEX_RX || spi->cur_comm == SPI_3WIRE_RX ||
1372 	    spi->cur_comm == SPI_FULL_DUPLEX) {
1373 		/*
1374 		 * In transmit-only mode, the OVR flag is set in the SR register
1375 		 * since the received data are never read. Therefore set OVR
1376 		 * interrupt only when rx buffer is available.
1377 		 */
1378 		stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_ERRIE);
1379 	}
1380 
1381 	stm32_spi_enable(spi);
1382 }
1383 
1384 /**
1385  * stm32f7_spi_transfer_one_dma_start - Set SPI driver registers to start
1386  *					transfer using DMA
1387  * @spi: pointer to the spi controller data structure
1388  */
1389 static void stm32f7_spi_transfer_one_dma_start(struct stm32_spi *spi)
1390 {
1391 	/* Configure DMA request trigger threshold according to DMA width */
1392 	if (spi->cur_bpw <= 8)
1393 		stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
1394 	else
1395 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR2, STM32F7_SPI_CR2_FRXTH);
1396 
1397 	stm32fx_spi_transfer_one_dma_start(spi);
1398 }
1399 
1400 /**
1401  * stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start
1402  *					transfer using DMA
1403  * @spi: pointer to the spi controller data structure
1404  */
1405 static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
1406 {
1407 	uint32_t ier = STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE;
1408 
1409 	/* Enable the interrupts */
1410 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX)
1411 		ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE;
1412 
1413 	stm32_spi_set_bits(spi, STM32H7_SPI_IER, ier);
1414 
1415 	stm32_spi_enable(spi);
1416 
1417 	if (STM32_SPI_HOST_MODE(spi))
1418 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
1419 }
1420 
1421 /**
1422  * stm32_spi_transfer_one_dma - transfer a single spi_transfer using DMA
1423  * @spi: pointer to the spi controller data structure
1424  * @xfer: pointer to the spi_transfer structure
1425  *
1426  * It must returns 0 if the transfer is finished or 1 if the transfer is still
1427  * in progress.
1428  */
1429 static int stm32_spi_transfer_one_dma(struct stm32_spi *spi,
1430 				      struct spi_transfer *xfer)
1431 {
1432 	struct dma_slave_config tx_dma_conf, rx_dma_conf;
1433 	struct dma_async_tx_descriptor *tx_dma_desc, *rx_dma_desc;
1434 	unsigned long flags;
1435 
1436 	spin_lock_irqsave(&spi->lock, flags);
1437 
1438 	rx_dma_desc = NULL;
1439 	if (spi->rx_buf && spi->dma_rx) {
1440 		stm32_spi_dma_config(spi, spi->dma_rx, &rx_dma_conf, DMA_DEV_TO_MEM);
1441 		dmaengine_slave_config(spi->dma_rx, &rx_dma_conf);
1442 
1443 		/* Enable Rx DMA request */
1444 		stm32_spi_set_bits(spi, spi->cfg->regs->dma_rx_en.reg,
1445 				   spi->cfg->regs->dma_rx_en.mask);
1446 
1447 		rx_dma_desc = dmaengine_prep_slave_sg(
1448 					spi->dma_rx, xfer->rx_sg.sgl,
1449 					xfer->rx_sg.nents,
1450 					rx_dma_conf.direction,
1451 					DMA_PREP_INTERRUPT);
1452 	}
1453 
1454 	tx_dma_desc = NULL;
1455 	if (spi->tx_buf && spi->dma_tx) {
1456 		stm32_spi_dma_config(spi, spi->dma_tx, &tx_dma_conf, DMA_MEM_TO_DEV);
1457 		dmaengine_slave_config(spi->dma_tx, &tx_dma_conf);
1458 
1459 		tx_dma_desc = dmaengine_prep_slave_sg(
1460 					spi->dma_tx, xfer->tx_sg.sgl,
1461 					xfer->tx_sg.nents,
1462 					tx_dma_conf.direction,
1463 					DMA_PREP_INTERRUPT);
1464 	}
1465 
1466 	if ((spi->tx_buf && spi->dma_tx && !tx_dma_desc) ||
1467 	    (spi->rx_buf && spi->dma_rx && !rx_dma_desc))
1468 		goto dma_desc_error;
1469 
1470 	if (spi->cur_comm == SPI_FULL_DUPLEX && (!tx_dma_desc || !rx_dma_desc))
1471 		goto dma_desc_error;
1472 
1473 	if (rx_dma_desc) {
1474 		rx_dma_desc->callback = spi->cfg->dma_rx_cb;
1475 		rx_dma_desc->callback_param = spi;
1476 
1477 		if (dma_submit_error(dmaengine_submit(rx_dma_desc))) {
1478 			dev_err(spi->dev, "Rx DMA submit failed\n");
1479 			goto dma_desc_error;
1480 		}
1481 		/* Enable Rx DMA channel */
1482 		dma_async_issue_pending(spi->dma_rx);
1483 	}
1484 
1485 	if (tx_dma_desc) {
1486 		if (spi->cur_comm == SPI_SIMPLEX_TX ||
1487 		    spi->cur_comm == SPI_3WIRE_TX) {
1488 			tx_dma_desc->callback = spi->cfg->dma_tx_cb;
1489 			tx_dma_desc->callback_param = spi;
1490 		}
1491 
1492 		if (dma_submit_error(dmaengine_submit(tx_dma_desc))) {
1493 			dev_err(spi->dev, "Tx DMA submit failed\n");
1494 			goto dma_submit_error;
1495 		}
1496 		/* Enable Tx DMA channel */
1497 		dma_async_issue_pending(spi->dma_tx);
1498 
1499 		/* Enable Tx DMA request */
1500 		stm32_spi_set_bits(spi, spi->cfg->regs->dma_tx_en.reg,
1501 				   spi->cfg->regs->dma_tx_en.mask);
1502 	}
1503 
1504 	spi->cfg->transfer_one_dma_start(spi);
1505 
1506 	spin_unlock_irqrestore(&spi->lock, flags);
1507 
1508 	return 1;
1509 
1510 dma_submit_error:
1511 	if (spi->dma_rx)
1512 		dmaengine_terminate_sync(spi->dma_rx);
1513 
1514 dma_desc_error:
1515 	stm32_spi_clr_bits(spi, spi->cfg->regs->dma_rx_en.reg,
1516 			   spi->cfg->regs->dma_rx_en.mask);
1517 
1518 	spin_unlock_irqrestore(&spi->lock, flags);
1519 
1520 	dev_info(spi->dev, "DMA issue: fall back to irq transfer\n");
1521 
1522 	spi->cur_usedma = false;
1523 	return spi->cfg->transfer_one_irq(spi);
1524 }
1525 
1526 /**
1527  * stm32f4_spi_set_bpw - Configure bits per word
1528  * @spi: pointer to the spi controller data structure
1529  */
1530 static void stm32f4_spi_set_bpw(struct stm32_spi *spi)
1531 {
1532 	if (spi->cur_bpw == 16)
1533 		stm32_spi_set_bits(spi, STM32FX_SPI_CR1, STM32F4_SPI_CR1_DFF);
1534 	else
1535 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR1, STM32F4_SPI_CR1_DFF);
1536 }
1537 
1538 /**
1539  * stm32f7_spi_set_bpw - Configure bits per word
1540  * @spi: pointer to the spi controller data structure
1541  */
1542 static void stm32f7_spi_set_bpw(struct stm32_spi *spi)
1543 {
1544 	u32 bpw;
1545 	u32 cr2_clrb = 0, cr2_setb = 0;
1546 
1547 	bpw = spi->cur_bpw - 1;
1548 
1549 	cr2_clrb |= STM32F7_SPI_CR2_DS;
1550 	cr2_setb |= FIELD_PREP(STM32F7_SPI_CR2_DS, bpw);
1551 
1552 	if (spi->rx_len >= sizeof(u16))
1553 		cr2_clrb |= STM32F7_SPI_CR2_FRXTH;
1554 	else
1555 		cr2_setb |= STM32F7_SPI_CR2_FRXTH;
1556 
1557 	writel_relaxed(
1558 		(readl_relaxed(spi->base + STM32FX_SPI_CR2) &
1559 		 ~cr2_clrb) | cr2_setb,
1560 		spi->base + STM32FX_SPI_CR2);
1561 }
1562 
1563 /**
1564  * stm32h7_spi_set_bpw - configure bits per word
1565  * @spi: pointer to the spi controller data structure
1566  */
1567 static void stm32h7_spi_set_bpw(struct stm32_spi *spi)
1568 {
1569 	u32 bpw, fthlv;
1570 	u32 cfg1_clrb = 0, cfg1_setb = 0;
1571 
1572 	bpw = spi->cur_bpw - 1;
1573 
1574 	cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE;
1575 	cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_DSIZE, bpw);
1576 
1577 	spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen);
1578 	fthlv = spi->cur_fthlv - 1;
1579 
1580 	cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
1581 	cfg1_setb |= FIELD_PREP(STM32H7_SPI_CFG1_FTHLV, fthlv);
1582 
1583 	writel_relaxed(
1584 		(readl_relaxed(spi->base + STM32H7_SPI_CFG1) &
1585 		 ~cfg1_clrb) | cfg1_setb,
1586 		spi->base + STM32H7_SPI_CFG1);
1587 }
1588 
1589 /**
1590  * stm32_spi_set_mbr - Configure baud rate divisor in host mode
1591  * @spi: pointer to the spi controller data structure
1592  * @mbrdiv: baud rate divisor value
1593  */
1594 static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv)
1595 {
1596 	u32 clrb = 0, setb = 0;
1597 
1598 	clrb |= spi->cfg->regs->br.mask;
1599 	setb |= (mbrdiv << spi->cfg->regs->br.shift) & spi->cfg->regs->br.mask;
1600 
1601 	writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) &
1602 			~clrb) | setb,
1603 		       spi->base + spi->cfg->regs->br.reg);
1604 }
1605 
1606 /**
1607  * stm32_spi_communication_type - return transfer communication type
1608  * @spi_dev: pointer to the spi device
1609  * @transfer: pointer to spi transfer
1610  */
1611 static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev,
1612 						 struct spi_transfer *transfer)
1613 {
1614 	unsigned int type = SPI_FULL_DUPLEX;
1615 
1616 	if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */
1617 		/*
1618 		 * SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL
1619 		 * is forbidden and unvalidated by SPI subsystem so depending
1620 		 * on the valid buffer, we can determine the direction of the
1621 		 * transfer.
1622 		 */
1623 		if (!transfer->tx_buf)
1624 			type = SPI_3WIRE_RX;
1625 		else
1626 			type = SPI_3WIRE_TX;
1627 	} else {
1628 		if (!transfer->tx_buf)
1629 			type = SPI_SIMPLEX_RX;
1630 		else if (!transfer->rx_buf)
1631 			type = SPI_SIMPLEX_TX;
1632 	}
1633 
1634 	return type;
1635 }
1636 
1637 /**
1638  * stm32fx_spi_set_mode - configure communication mode
1639  * @spi: pointer to the spi controller data structure
1640  * @comm_type: type of communication to configure
1641  */
1642 static int stm32fx_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
1643 {
1644 	if (comm_type == SPI_3WIRE_TX || comm_type == SPI_SIMPLEX_TX) {
1645 		stm32_spi_set_bits(spi, STM32FX_SPI_CR1,
1646 					STM32FX_SPI_CR1_BIDIMODE |
1647 					STM32FX_SPI_CR1_BIDIOE);
1648 	} else if (comm_type == SPI_FULL_DUPLEX ||
1649 				comm_type == SPI_SIMPLEX_RX) {
1650 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR1,
1651 					STM32FX_SPI_CR1_BIDIMODE |
1652 					STM32FX_SPI_CR1_BIDIOE);
1653 	} else if (comm_type == SPI_3WIRE_RX) {
1654 		stm32_spi_set_bits(spi, STM32FX_SPI_CR1,
1655 					STM32FX_SPI_CR1_BIDIMODE);
1656 		stm32_spi_clr_bits(spi, STM32FX_SPI_CR1,
1657 					STM32FX_SPI_CR1_BIDIOE);
1658 	} else {
1659 		return -EINVAL;
1660 	}
1661 
1662 	return 0;
1663 }
1664 
1665 /**
1666  * stm32h7_spi_set_mode - configure communication mode
1667  * @spi: pointer to the spi controller data structure
1668  * @comm_type: type of communication to configure
1669  */
1670 static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type)
1671 {
1672 	u32 mode;
1673 	u32 cfg2_clrb = 0, cfg2_setb = 0;
1674 
1675 	if (comm_type == SPI_3WIRE_RX) {
1676 		mode = STM32H7_SPI_HALF_DUPLEX;
1677 		stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
1678 	} else if (comm_type == SPI_3WIRE_TX) {
1679 		mode = STM32H7_SPI_HALF_DUPLEX;
1680 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR);
1681 	} else if (comm_type == SPI_SIMPLEX_RX) {
1682 		mode = STM32H7_SPI_SIMPLEX_RX;
1683 	} else if (comm_type == SPI_SIMPLEX_TX) {
1684 		mode = STM32H7_SPI_SIMPLEX_TX;
1685 	} else {
1686 		mode = STM32H7_SPI_FULL_DUPLEX;
1687 	}
1688 
1689 	cfg2_clrb |= STM32H7_SPI_CFG2_COMM;
1690 	cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_COMM, mode);
1691 
1692 	writel_relaxed(
1693 		(readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
1694 		 ~cfg2_clrb) | cfg2_setb,
1695 		spi->base + STM32H7_SPI_CFG2);
1696 
1697 	return 0;
1698 }
1699 
1700 /**
1701  * stm32h7_spi_data_idleness - configure minimum time delay inserted between two
1702  *			       consecutive data frames in host mode
1703  * @spi: pointer to the spi controller data structure
1704  * @len: transfer len
1705  */
1706 static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len)
1707 {
1708 	u32 cfg2_clrb = 0, cfg2_setb = 0;
1709 
1710 	cfg2_clrb |= STM32H7_SPI_CFG2_MIDI;
1711 	if ((len > 1) && (spi->cur_midi > 0)) {
1712 		u32 sck_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, spi->cur_speed);
1713 		u32 midi = min_t(u32,
1714 				 DIV_ROUND_UP(spi->cur_midi, sck_period_ns),
1715 				 FIELD_GET(STM32H7_SPI_CFG2_MIDI,
1716 				 STM32H7_SPI_CFG2_MIDI));
1717 
1718 
1719 		dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n",
1720 			sck_period_ns, midi, midi * sck_period_ns);
1721 		cfg2_setb |= FIELD_PREP(STM32H7_SPI_CFG2_MIDI, midi);
1722 	}
1723 
1724 	writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) &
1725 			~cfg2_clrb) | cfg2_setb,
1726 		       spi->base + STM32H7_SPI_CFG2);
1727 }
1728 
1729 /**
1730  * stm32h7_spi_number_of_data - configure number of data at current transfer
1731  * @spi: pointer to the spi controller data structure
1732  * @nb_words: transfer length (in words)
1733  */
1734 static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words)
1735 {
1736 	if (nb_words <= spi->t_size_max) {
1737 		writel_relaxed(FIELD_PREP(STM32H7_SPI_CR2_TSIZE, nb_words),
1738 			       spi->base + STM32H7_SPI_CR2);
1739 	} else {
1740 		return -EMSGSIZE;
1741 	}
1742 
1743 	return 0;
1744 }
1745 
1746 /**
1747  * stm32_spi_transfer_one_setup - common setup to transfer a single
1748  *				  spi_transfer either using DMA or
1749  *				  interrupts.
1750  * @spi: pointer to the spi controller data structure
1751  * @spi_dev: pointer to the spi device
1752  * @transfer: pointer to spi transfer
1753  */
1754 static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
1755 					struct spi_device *spi_dev,
1756 					struct spi_transfer *transfer)
1757 {
1758 	unsigned long flags;
1759 	unsigned int comm_type;
1760 	int nb_words, ret = 0;
1761 	int mbr;
1762 
1763 	spin_lock_irqsave(&spi->lock, flags);
1764 
1765 	spi->cur_xferlen = transfer->len;
1766 
1767 	spi->cur_bpw = transfer->bits_per_word;
1768 	spi->cfg->set_bpw(spi);
1769 
1770 	/* Update spi->cur_speed with real clock speed */
1771 	if (STM32_SPI_HOST_MODE(spi)) {
1772 		mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
1773 					    spi->cfg->baud_rate_div_min,
1774 					    spi->cfg->baud_rate_div_max);
1775 		if (mbr < 0) {
1776 			ret = mbr;
1777 			goto out;
1778 		}
1779 
1780 		transfer->speed_hz = spi->cur_speed;
1781 		stm32_spi_set_mbr(spi, mbr);
1782 	}
1783 
1784 	comm_type = stm32_spi_communication_type(spi_dev, transfer);
1785 	ret = spi->cfg->set_mode(spi, comm_type);
1786 	if (ret < 0)
1787 		goto out;
1788 
1789 	spi->cur_comm = comm_type;
1790 
1791 	if (STM32_SPI_HOST_MODE(spi) && spi->cfg->set_data_idleness)
1792 		spi->cfg->set_data_idleness(spi, transfer->len);
1793 
1794 	if (spi->cur_bpw <= 8)
1795 		nb_words = transfer->len;
1796 	else if (spi->cur_bpw <= 16)
1797 		nb_words = DIV_ROUND_UP(transfer->len * 8, 16);
1798 	else
1799 		nb_words = DIV_ROUND_UP(transfer->len * 8, 32);
1800 
1801 	if (spi->cfg->set_number_of_data) {
1802 		ret = spi->cfg->set_number_of_data(spi, nb_words);
1803 		if (ret < 0)
1804 			goto out;
1805 	}
1806 
1807 	dev_dbg(spi->dev, "transfer communication mode set to %d\n",
1808 		spi->cur_comm);
1809 	dev_dbg(spi->dev,
1810 		"data frame of %d-bit, data packet of %d data frames\n",
1811 		spi->cur_bpw, spi->cur_fthlv);
1812 	if (STM32_SPI_HOST_MODE(spi))
1813 		dev_dbg(spi->dev, "speed set to %dHz\n", spi->cur_speed);
1814 	dev_dbg(spi->dev, "transfer of %d bytes (%d data frames)\n",
1815 		spi->cur_xferlen, nb_words);
1816 	dev_dbg(spi->dev, "dma %s\n",
1817 		(spi->cur_usedma) ? "enabled" : "disabled");
1818 
1819 out:
1820 	spin_unlock_irqrestore(&spi->lock, flags);
1821 
1822 	return ret;
1823 }
1824 
1825 /**
1826  * stm32_spi_transfer_one - transfer a single spi_transfer
1827  * @ctrl: controller interface
1828  * @spi_dev: pointer to the spi device
1829  * @transfer: pointer to spi transfer
1830  *
1831  * It must return 0 if the transfer is finished or 1 if the transfer is still
1832  * in progress.
1833  */
1834 static int stm32_spi_transfer_one(struct spi_controller *ctrl,
1835 				  struct spi_device *spi_dev,
1836 				  struct spi_transfer *transfer)
1837 {
1838 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1839 	int ret;
1840 
1841 	spi->tx_buf = transfer->tx_buf;
1842 	spi->rx_buf = transfer->rx_buf;
1843 	spi->tx_len = spi->tx_buf ? transfer->len : 0;
1844 	spi->rx_len = spi->rx_buf ? transfer->len : 0;
1845 
1846 	spi->cur_usedma = (ctrl->can_dma &&
1847 			   ctrl->can_dma(ctrl, spi_dev, transfer));
1848 
1849 	ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer);
1850 	if (ret) {
1851 		dev_err(spi->dev, "SPI transfer setup failed\n");
1852 		return ret;
1853 	}
1854 
1855 	if (spi->cur_usedma)
1856 		return stm32_spi_transfer_one_dma(spi, transfer);
1857 	else
1858 		return spi->cfg->transfer_one_irq(spi);
1859 }
1860 
1861 /**
1862  * stm32_spi_unprepare_msg - relax the hardware
1863  * @ctrl: controller interface
1864  * @msg: pointer to the spi message
1865  */
1866 static int stm32_spi_unprepare_msg(struct spi_controller *ctrl,
1867 				   struct spi_message *msg)
1868 {
1869 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
1870 
1871 	spi->cfg->disable(spi);
1872 
1873 	return 0;
1874 }
1875 
1876 /**
1877  * stm32fx_spi_config - Configure SPI controller as SPI host
1878  * @spi: pointer to the spi controller data structure
1879  */
1880 static int stm32fx_spi_config(struct stm32_spi *spi)
1881 {
1882 	unsigned long flags;
1883 
1884 	spin_lock_irqsave(&spi->lock, flags);
1885 
1886 	/* Ensure I2SMOD bit is kept cleared */
1887 	stm32_spi_clr_bits(spi, STM32FX_SPI_I2SCFGR,
1888 			   STM32FX_SPI_I2SCFGR_I2SMOD);
1889 
1890 	/*
1891 	 * - SS input value high
1892 	 * - transmitter half duplex direction
1893 	 * - Set the host mode (default Motorola mode)
1894 	 * - Consider 1 host/n targets configuration and
1895 	 *   SS input value is determined by the SSI bit
1896 	 */
1897 	stm32_spi_set_bits(spi, STM32FX_SPI_CR1, STM32FX_SPI_CR1_SSI |
1898 						 STM32FX_SPI_CR1_BIDIOE |
1899 						 STM32FX_SPI_CR1_MSTR |
1900 						 STM32FX_SPI_CR1_SSM);
1901 
1902 	spin_unlock_irqrestore(&spi->lock, flags);
1903 
1904 	return 0;
1905 }
1906 
1907 /**
1908  * stm32h7_spi_config - Configure SPI controller
1909  * @spi: pointer to the spi controller data structure
1910  */
1911 static int stm32h7_spi_config(struct stm32_spi *spi)
1912 {
1913 	unsigned long flags;
1914 	u32 cr1 = 0, cfg2 = 0;
1915 
1916 	spin_lock_irqsave(&spi->lock, flags);
1917 
1918 	/* Ensure I2SMOD bit is kept cleared */
1919 	stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR,
1920 			   STM32H7_SPI_I2SCFGR_I2SMOD);
1921 
1922 	if (STM32_SPI_DEVICE_MODE(spi)) {
1923 		/* Use native device select */
1924 		cfg2 &= ~STM32H7_SPI_CFG2_SSM;
1925 	} else {
1926 		/*
1927 		 * - Transmitter half duplex direction
1928 		 * - Automatic communication suspend when RX-Fifo is full
1929 		 * - SS input value high
1930 		 */
1931 		cr1 |= STM32H7_SPI_CR1_HDDIR | STM32H7_SPI_CR1_MASRX | STM32H7_SPI_CR1_SSI;
1932 
1933 		/*
1934 		 * - Set the host mode (default Motorola mode)
1935 		 * - Consider 1 host/n devices configuration and
1936 		 *   SS input value is determined by the SSI bit
1937 		 * - keep control of all associated GPIOs
1938 		 */
1939 		cfg2 |= STM32H7_SPI_CFG2_MASTER | STM32H7_SPI_CFG2_SSM | STM32H7_SPI_CFG2_AFCNTR;
1940 	}
1941 
1942 	stm32_spi_set_bits(spi, STM32H7_SPI_CR1, cr1);
1943 	stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, cfg2);
1944 
1945 	spin_unlock_irqrestore(&spi->lock, flags);
1946 
1947 	return 0;
1948 }
1949 
1950 static const struct stm32_spi_cfg stm32f4_spi_cfg = {
1951 	.regs = &stm32fx_spi_regspec,
1952 	.get_bpw_mask = stm32f4_spi_get_bpw_mask,
1953 	.disable = stm32fx_spi_disable,
1954 	.config = stm32fx_spi_config,
1955 	.set_bpw = stm32f4_spi_set_bpw,
1956 	.set_mode = stm32fx_spi_set_mode,
1957 	.write_tx = stm32f4_spi_write_tx,
1958 	.read_rx = stm32f4_spi_read_rx,
1959 	.transfer_one_dma_start = stm32fx_spi_transfer_one_dma_start,
1960 	.dma_tx_cb = stm32fx_spi_dma_tx_cb,
1961 	.dma_rx_cb = stm32_spi_dma_rx_cb,
1962 	.transfer_one_irq = stm32fx_spi_transfer_one_irq,
1963 	.irq_handler_event = stm32fx_spi_irq_event,
1964 	.irq_handler_thread = stm32fx_spi_irq_thread,
1965 	.baud_rate_div_min = STM32FX_SPI_BR_DIV_MIN,
1966 	.baud_rate_div_max = STM32FX_SPI_BR_DIV_MAX,
1967 	.has_fifo = false,
1968 	.has_device_mode = false,
1969 	.flags = SPI_CONTROLLER_MUST_TX,
1970 };
1971 
1972 static const struct stm32_spi_cfg stm32f7_spi_cfg = {
1973 	.regs = &stm32fx_spi_regspec,
1974 	.get_bpw_mask = stm32f7_spi_get_bpw_mask,
1975 	.disable = stm32fx_spi_disable,
1976 	.config = stm32fx_spi_config,
1977 	.set_bpw = stm32f7_spi_set_bpw,
1978 	.set_mode = stm32fx_spi_set_mode,
1979 	.write_tx = stm32f7_spi_write_tx,
1980 	.read_rx = stm32f7_spi_read_rx,
1981 	.transfer_one_dma_start = stm32f7_spi_transfer_one_dma_start,
1982 	.dma_tx_cb = stm32fx_spi_dma_tx_cb,
1983 	.dma_rx_cb = stm32_spi_dma_rx_cb,
1984 	.transfer_one_irq = stm32fx_spi_transfer_one_irq,
1985 	.irq_handler_event = stm32fx_spi_irq_event,
1986 	.irq_handler_thread = stm32fx_spi_irq_thread,
1987 	.baud_rate_div_min = STM32FX_SPI_BR_DIV_MIN,
1988 	.baud_rate_div_max = STM32FX_SPI_BR_DIV_MAX,
1989 	.has_fifo = false,
1990 	.flags = SPI_CONTROLLER_MUST_TX,
1991 };
1992 
1993 static const struct stm32_spi_cfg stm32h7_spi_cfg = {
1994 	.regs = &stm32h7_spi_regspec,
1995 	.get_fifo_size = stm32h7_spi_get_fifo_size,
1996 	.get_bpw_mask = stm32h7_spi_get_bpw_mask,
1997 	.disable = stm32h7_spi_disable,
1998 	.config = stm32h7_spi_config,
1999 	.set_bpw = stm32h7_spi_set_bpw,
2000 	.set_mode = stm32h7_spi_set_mode,
2001 	.set_data_idleness = stm32h7_spi_data_idleness,
2002 	.set_number_of_data = stm32h7_spi_number_of_data,
2003 	.write_tx = stm32h7_spi_write_txfifo,
2004 	.read_rx = stm32h7_spi_read_rxfifo,
2005 	.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
2006 	.dma_rx_cb = stm32_spi_dma_rx_cb,
2007 	/*
2008 	 * dma_tx_cb is not necessary since in case of TX, dma is followed by
2009 	 * SPI access hence handling is performed within the SPI interrupt
2010 	 */
2011 	.transfer_one_irq = stm32h7_spi_transfer_one_irq,
2012 	.irq_handler_thread = stm32h7_spi_irq_thread,
2013 	.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
2014 	.baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
2015 	.has_fifo = true,
2016 	.has_device_mode = true,
2017 };
2018 
2019 /*
2020  * STM32MP2 is compatible with the STM32H7 except:
2021  * - enforce the DMA maxburst value to 1
2022  * - spi8 have limited feature set (TSIZE_MAX = 1024, BPW of 8 OR 16)
2023  */
2024 static const struct stm32_spi_cfg stm32mp25_spi_cfg = {
2025 	.regs = &stm32mp25_spi_regspec,
2026 	.get_fifo_size = stm32h7_spi_get_fifo_size,
2027 	.get_bpw_mask = stm32mp25_spi_get_bpw_mask,
2028 	.disable = stm32h7_spi_disable,
2029 	.config = stm32h7_spi_config,
2030 	.set_bpw = stm32h7_spi_set_bpw,
2031 	.set_mode = stm32h7_spi_set_mode,
2032 	.set_data_idleness = stm32h7_spi_data_idleness,
2033 	.set_number_of_data = stm32h7_spi_number_of_data,
2034 	.transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start,
2035 	.dma_rx_cb = stm32_spi_dma_rx_cb,
2036 	/*
2037 	 * dma_tx_cb is not necessary since in case of TX, dma is followed by
2038 	 * SPI access hence handling is performed within the SPI interrupt
2039 	 */
2040 	.transfer_one_irq = stm32h7_spi_transfer_one_irq,
2041 	.irq_handler_thread = stm32h7_spi_irq_thread,
2042 	.baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN,
2043 	.baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX,
2044 	.has_fifo = true,
2045 	.prevent_dma_burst = true,
2046 };
2047 
2048 static const struct of_device_id stm32_spi_of_match[] = {
2049 	{ .compatible = "st,stm32mp25-spi", .data = (void *)&stm32mp25_spi_cfg },
2050 	{ .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg },
2051 	{ .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg },
2052 	{ .compatible = "st,stm32f7-spi", .data = (void *)&stm32f7_spi_cfg },
2053 	{},
2054 };
2055 MODULE_DEVICE_TABLE(of, stm32_spi_of_match);
2056 
2057 static int stm32h7_spi_device_abort(struct spi_controller *ctrl)
2058 {
2059 	spi_finalize_current_transfer(ctrl);
2060 	return 0;
2061 }
2062 
2063 static int stm32_spi_probe(struct platform_device *pdev)
2064 {
2065 	struct spi_controller *ctrl;
2066 	struct stm32_spi *spi;
2067 	struct resource *res;
2068 	struct reset_control *rst;
2069 	struct device_node *np = pdev->dev.of_node;
2070 	bool device_mode;
2071 	int ret;
2072 	const struct stm32_spi_cfg *cfg = of_device_get_match_data(&pdev->dev);
2073 
2074 	device_mode = of_property_read_bool(np, "spi-slave");
2075 	if (!cfg->has_device_mode && device_mode) {
2076 		dev_err(&pdev->dev, "spi-slave not supported\n");
2077 		return -EPERM;
2078 	}
2079 
2080 	if (device_mode)
2081 		ctrl = devm_spi_alloc_target(&pdev->dev, sizeof(struct stm32_spi));
2082 	else
2083 		ctrl = devm_spi_alloc_host(&pdev->dev, sizeof(struct stm32_spi));
2084 	if (!ctrl) {
2085 		dev_err(&pdev->dev, "spi controller allocation failed\n");
2086 		return -ENOMEM;
2087 	}
2088 	platform_set_drvdata(pdev, ctrl);
2089 
2090 	spi = spi_controller_get_devdata(ctrl);
2091 	spi->dev = &pdev->dev;
2092 	spi->ctrl = ctrl;
2093 	spi->device_mode = device_mode;
2094 	spin_lock_init(&spi->lock);
2095 
2096 	spi->cfg = cfg;
2097 
2098 	spi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2099 	if (IS_ERR(spi->base))
2100 		return PTR_ERR(spi->base);
2101 
2102 	spi->phys_addr = (dma_addr_t)res->start;
2103 
2104 	spi->irq = platform_get_irq(pdev, 0);
2105 	if (spi->irq <= 0)
2106 		return spi->irq;
2107 
2108 	ret = devm_request_threaded_irq(&pdev->dev, spi->irq,
2109 					spi->cfg->irq_handler_event,
2110 					spi->cfg->irq_handler_thread,
2111 					IRQF_ONESHOT, pdev->name, ctrl);
2112 	if (ret) {
2113 		dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq,
2114 			ret);
2115 		return ret;
2116 	}
2117 
2118 	spi->clk = devm_clk_get(&pdev->dev, NULL);
2119 	if (IS_ERR(spi->clk)) {
2120 		ret = PTR_ERR(spi->clk);
2121 		dev_err(&pdev->dev, "clk get failed: %d\n", ret);
2122 		return ret;
2123 	}
2124 
2125 	ret = clk_prepare_enable(spi->clk);
2126 	if (ret) {
2127 		dev_err(&pdev->dev, "clk enable failed: %d\n", ret);
2128 		return ret;
2129 	}
2130 	spi->clk_rate = clk_get_rate(spi->clk);
2131 	if (!spi->clk_rate) {
2132 		dev_err(&pdev->dev, "clk rate = 0\n");
2133 		ret = -EINVAL;
2134 		goto err_clk_disable;
2135 	}
2136 
2137 	rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
2138 	if (rst) {
2139 		if (IS_ERR(rst)) {
2140 			ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
2141 					    "failed to get reset\n");
2142 			goto err_clk_disable;
2143 		}
2144 
2145 		reset_control_assert(rst);
2146 		udelay(2);
2147 		reset_control_deassert(rst);
2148 	}
2149 
2150 	if (spi->cfg->has_fifo)
2151 		spi->fifo_size = spi->cfg->get_fifo_size(spi);
2152 
2153 	spi->feature_set = STM32_SPI_FEATURE_FULL;
2154 	if (spi->cfg->regs->fullcfg.reg) {
2155 		spi->feature_set =
2156 			FIELD_GET(STM32MP25_SPI_HWCFGR1_FULLCFG,
2157 				  readl_relaxed(spi->base + spi->cfg->regs->fullcfg.reg));
2158 
2159 		dev_dbg(spi->dev, "%s feature set\n",
2160 			spi->feature_set == STM32_SPI_FEATURE_FULL ? "full" : "limited");
2161 	}
2162 
2163 	/* Only for STM32H7 and after */
2164 	spi->t_size_max = spi->feature_set == STM32_SPI_FEATURE_FULL ?
2165 				STM32H7_SPI_TSIZE_MAX :
2166 				STM32MP25_SPI_TSIZE_MAX_LIMITED;
2167 	dev_dbg(spi->dev, "one message max size %d\n", spi->t_size_max);
2168 
2169 	ret = spi->cfg->config(spi);
2170 	if (ret) {
2171 		dev_err(&pdev->dev, "controller configuration failed: %d\n",
2172 			ret);
2173 		goto err_clk_disable;
2174 	}
2175 
2176 	ctrl->dev.of_node = pdev->dev.of_node;
2177 	ctrl->auto_runtime_pm = true;
2178 	ctrl->bus_num = pdev->id;
2179 	ctrl->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
2180 			  SPI_3WIRE;
2181 	ctrl->bits_per_word_mask = spi->cfg->get_bpw_mask(spi);
2182 	ctrl->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min;
2183 	ctrl->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max;
2184 	ctrl->use_gpio_descriptors = true;
2185 	ctrl->prepare_message = stm32_spi_prepare_msg;
2186 	ctrl->transfer_one = stm32_spi_transfer_one;
2187 	ctrl->unprepare_message = stm32_spi_unprepare_msg;
2188 	ctrl->flags = spi->cfg->flags;
2189 	if (STM32_SPI_DEVICE_MODE(spi))
2190 		ctrl->target_abort = stm32h7_spi_device_abort;
2191 
2192 	spi->dma_tx = dma_request_chan(spi->dev, "tx");
2193 	if (IS_ERR(spi->dma_tx)) {
2194 		ret = PTR_ERR(spi->dma_tx);
2195 		spi->dma_tx = NULL;
2196 		if (ret == -EPROBE_DEFER)
2197 			goto err_clk_disable;
2198 
2199 		dev_warn(&pdev->dev, "failed to request tx dma channel\n");
2200 	} else {
2201 		ctrl->dma_tx = spi->dma_tx;
2202 	}
2203 
2204 	spi->dma_rx = dma_request_chan(spi->dev, "rx");
2205 	if (IS_ERR(spi->dma_rx)) {
2206 		ret = PTR_ERR(spi->dma_rx);
2207 		spi->dma_rx = NULL;
2208 		if (ret == -EPROBE_DEFER)
2209 			goto err_dma_release;
2210 
2211 		dev_warn(&pdev->dev, "failed to request rx dma channel\n");
2212 	} else {
2213 		ctrl->dma_rx = spi->dma_rx;
2214 	}
2215 
2216 	if (spi->dma_tx || spi->dma_rx)
2217 		ctrl->can_dma = stm32_spi_can_dma;
2218 
2219 	pm_runtime_set_autosuspend_delay(&pdev->dev,
2220 					 STM32_SPI_AUTOSUSPEND_DELAY);
2221 	pm_runtime_use_autosuspend(&pdev->dev);
2222 	pm_runtime_set_active(&pdev->dev);
2223 	pm_runtime_get_noresume(&pdev->dev);
2224 	pm_runtime_enable(&pdev->dev);
2225 
2226 	ret = spi_register_controller(ctrl);
2227 	if (ret) {
2228 		dev_err(&pdev->dev, "spi controller registration failed: %d\n",
2229 			ret);
2230 		goto err_pm_disable;
2231 	}
2232 
2233 	pm_runtime_mark_last_busy(&pdev->dev);
2234 	pm_runtime_put_autosuspend(&pdev->dev);
2235 
2236 	dev_info(&pdev->dev, "driver initialized (%s mode)\n",
2237 		 STM32_SPI_HOST_MODE(spi) ? "host" : "device");
2238 
2239 	return 0;
2240 
2241 err_pm_disable:
2242 	pm_runtime_disable(&pdev->dev);
2243 	pm_runtime_put_noidle(&pdev->dev);
2244 	pm_runtime_set_suspended(&pdev->dev);
2245 	pm_runtime_dont_use_autosuspend(&pdev->dev);
2246 err_dma_release:
2247 	if (spi->dma_tx)
2248 		dma_release_channel(spi->dma_tx);
2249 	if (spi->dma_rx)
2250 		dma_release_channel(spi->dma_rx);
2251 err_clk_disable:
2252 	clk_disable_unprepare(spi->clk);
2253 
2254 	return ret;
2255 }
2256 
2257 static void stm32_spi_remove(struct platform_device *pdev)
2258 {
2259 	struct spi_controller *ctrl = platform_get_drvdata(pdev);
2260 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2261 
2262 	pm_runtime_get_sync(&pdev->dev);
2263 
2264 	spi_unregister_controller(ctrl);
2265 	spi->cfg->disable(spi);
2266 
2267 	pm_runtime_disable(&pdev->dev);
2268 	pm_runtime_put_noidle(&pdev->dev);
2269 	pm_runtime_set_suspended(&pdev->dev);
2270 	pm_runtime_dont_use_autosuspend(&pdev->dev);
2271 
2272 	if (ctrl->dma_tx)
2273 		dma_release_channel(ctrl->dma_tx);
2274 	if (ctrl->dma_rx)
2275 		dma_release_channel(ctrl->dma_rx);
2276 
2277 	clk_disable_unprepare(spi->clk);
2278 
2279 
2280 	pinctrl_pm_select_sleep_state(&pdev->dev);
2281 }
2282 
2283 static int __maybe_unused stm32_spi_runtime_suspend(struct device *dev)
2284 {
2285 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2286 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2287 
2288 	clk_disable_unprepare(spi->clk);
2289 
2290 	return pinctrl_pm_select_sleep_state(dev);
2291 }
2292 
2293 static int __maybe_unused stm32_spi_runtime_resume(struct device *dev)
2294 {
2295 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2296 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2297 	int ret;
2298 
2299 	ret = pinctrl_pm_select_default_state(dev);
2300 	if (ret)
2301 		return ret;
2302 
2303 	return clk_prepare_enable(spi->clk);
2304 }
2305 
2306 static int __maybe_unused stm32_spi_suspend(struct device *dev)
2307 {
2308 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2309 	int ret;
2310 
2311 	ret = spi_controller_suspend(ctrl);
2312 	if (ret)
2313 		return ret;
2314 
2315 	return pm_runtime_force_suspend(dev);
2316 }
2317 
2318 static int __maybe_unused stm32_spi_resume(struct device *dev)
2319 {
2320 	struct spi_controller *ctrl = dev_get_drvdata(dev);
2321 	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
2322 	int ret;
2323 
2324 	ret = pm_runtime_force_resume(dev);
2325 	if (ret)
2326 		return ret;
2327 
2328 	ret = spi_controller_resume(ctrl);
2329 	if (ret) {
2330 		clk_disable_unprepare(spi->clk);
2331 		return ret;
2332 	}
2333 
2334 	ret = pm_runtime_resume_and_get(dev);
2335 	if (ret < 0) {
2336 		dev_err(dev, "Unable to power device:%d\n", ret);
2337 		return ret;
2338 	}
2339 
2340 	spi->cfg->config(spi);
2341 
2342 	pm_runtime_mark_last_busy(dev);
2343 	pm_runtime_put_autosuspend(dev);
2344 
2345 	return 0;
2346 }
2347 
2348 static const struct dev_pm_ops stm32_spi_pm_ops = {
2349 	SET_SYSTEM_SLEEP_PM_OPS(stm32_spi_suspend, stm32_spi_resume)
2350 	SET_RUNTIME_PM_OPS(stm32_spi_runtime_suspend,
2351 			   stm32_spi_runtime_resume, NULL)
2352 };
2353 
2354 static struct platform_driver stm32_spi_driver = {
2355 	.probe = stm32_spi_probe,
2356 	.remove_new = stm32_spi_remove,
2357 	.driver = {
2358 		.name = DRIVER_NAME,
2359 		.pm = &stm32_spi_pm_ops,
2360 		.of_match_table = stm32_spi_of_match,
2361 	},
2362 };
2363 
2364 module_platform_driver(stm32_spi_driver);
2365 
2366 MODULE_ALIAS("platform:" DRIVER_NAME);
2367 MODULE_DESCRIPTION("STMicroelectronics STM32 SPI Controller driver");
2368 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
2369 MODULE_LICENSE("GPL v2");
2370