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83c624d8 FC |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Renesas RZ/V2M Clocked Serial Interface (CSI) driver | |
4 | * | |
5 | * Copyright (C) 2023 Renesas Electronics Corporation | |
6 | */ | |
7 | ||
f572ba79 | 8 | #include <linux/bits.h> |
83c624d8 FC |
9 | #include <linux/clk.h> |
10 | #include <linux/count_zeros.h> | |
11 | #include <linux/interrupt.h> | |
12 | #include <linux/iopoll.h> | |
7b63568f | 13 | #include <linux/log2.h> |
a4f7ef6d | 14 | #include <linux/of.h> |
83c624d8 | 15 | #include <linux/platform_device.h> |
c5a7b668 | 16 | #include <linux/property.h> |
83c624d8 FC |
17 | #include <linux/reset.h> |
18 | #include <linux/spi/spi.h> | |
74e27ce8 | 19 | #include <linux/units.h> |
83c624d8 FC |
20 | |
21 | /* Registers */ | |
22 | #define CSI_MODE 0x00 /* CSI mode control */ | |
23 | #define CSI_CLKSEL 0x04 /* CSI clock select */ | |
24 | #define CSI_CNT 0x08 /* CSI control */ | |
25 | #define CSI_INT 0x0C /* CSI interrupt status */ | |
26 | #define CSI_IFIFOL 0x10 /* CSI receive FIFO level display */ | |
27 | #define CSI_OFIFOL 0x14 /* CSI transmit FIFO level display */ | |
28 | #define CSI_IFIFO 0x18 /* CSI receive window */ | |
29 | #define CSI_OFIFO 0x1C /* CSI transmit window */ | |
30 | #define CSI_FIFOTRG 0x20 /* CSI FIFO trigger level */ | |
31 | ||
32 | /* CSI_MODE */ | |
33 | #define CSI_MODE_CSIE BIT(7) | |
34 | #define CSI_MODE_TRMD BIT(6) | |
35 | #define CSI_MODE_CCL BIT(5) | |
36 | #define CSI_MODE_DIR BIT(4) | |
37 | #define CSI_MODE_CSOT BIT(0) | |
38 | ||
39 | #define CSI_MODE_SETUP 0x00000040 | |
40 | ||
41 | /* CSI_CLKSEL */ | |
a4f7ef6d FC |
42 | #define CSI_CLKSEL_SS_ENA BIT(19) |
43 | #define CSI_CLKSEL_SS_POL BIT(18) | |
44 | #define CSI_CLKSEL_SS (CSI_CLKSEL_SS_ENA | CSI_CLKSEL_SS_POL) | |
83c624d8 FC |
45 | #define CSI_CLKSEL_CKP BIT(17) |
46 | #define CSI_CLKSEL_DAP BIT(16) | |
d5737d12 | 47 | #define CSI_CLKSEL_MODE (CSI_CLKSEL_CKP|CSI_CLKSEL_DAP) |
83c624d8 FC |
48 | #define CSI_CLKSEL_SLAVE BIT(15) |
49 | #define CSI_CLKSEL_CKS GENMASK(14, 1) | |
50 | ||
51 | /* CSI_CNT */ | |
52 | #define CSI_CNT_CSIRST BIT(28) | |
53 | #define CSI_CNT_R_TRGEN BIT(19) | |
54 | #define CSI_CNT_UNDER_E BIT(13) | |
55 | #define CSI_CNT_OVERF_E BIT(12) | |
56 | #define CSI_CNT_TREND_E BIT(9) | |
57 | #define CSI_CNT_CSIEND_E BIT(8) | |
58 | #define CSI_CNT_T_TRGR_E BIT(4) | |
59 | #define CSI_CNT_R_TRGR_E BIT(0) | |
60 | ||
61 | /* CSI_INT */ | |
62 | #define CSI_INT_UNDER BIT(13) | |
63 | #define CSI_INT_OVERF BIT(12) | |
64 | #define CSI_INT_TREND BIT(9) | |
65 | #define CSI_INT_CSIEND BIT(8) | |
66 | #define CSI_INT_T_TRGR BIT(4) | |
67 | #define CSI_INT_R_TRGR BIT(0) | |
68 | ||
69 | /* CSI_FIFOTRG */ | |
70 | #define CSI_FIFOTRG_R_TRG GENMASK(2, 0) | |
71 | ||
8dc4038a FC |
72 | #define CSI_FIFO_SIZE_BYTES 32U |
73 | #define CSI_FIFO_HALF_SIZE 16U | |
83c624d8 | 74 | #define CSI_EN_DIS_TIMEOUT_US 100 |
aecf9fbd FC |
75 | /* |
76 | * Clock "csiclk" gets divided by 2 * CSI_CLKSEL_CKS in order to generate the | |
77 | * serial clock (output from master), with CSI_CLKSEL_CKS ranging from 0x1 (that | |
78 | * means "csiclk" is divided by 2) to 0x3FFF ("csiclk" is divided by 32766). | |
79 | */ | |
80 | #define CSI_CKS_MAX GENMASK(13, 0) | |
83c624d8 FC |
81 | |
82 | #define UNDERRUN_ERROR BIT(0) | |
83 | #define OVERFLOW_ERROR BIT(1) | |
84 | #define TX_TIMEOUT_ERROR BIT(2) | |
85 | #define RX_TIMEOUT_ERROR BIT(3) | |
86 | ||
74e27ce8 | 87 | #define CSI_MAX_SPI_SCKO (8 * HZ_PER_MHZ) |
83c624d8 | 88 | |
a4f7ef6d FC |
89 | #define CSI_CLKSEL_SS_DISABLED 0 |
90 | #define CSI_CLKSEL_SS_ENABLED_ACTIVE_LOW BIT(1) | |
91 | #define CSI_CLKSEL_SS_ENABLED_ACTIVE_HIGH GENMASK(1, 0) | |
92 | ||
83c624d8 FC |
93 | struct rzv2m_csi_priv { |
94 | void __iomem *base; | |
95 | struct clk *csiclk; | |
96 | struct clk *pclk; | |
97 | struct device *dev; | |
98 | struct spi_controller *controller; | |
8dc4038a FC |
99 | const void *txbuf; |
100 | void *rxbuf; | |
101 | unsigned int buffer_len; | |
102 | unsigned int bytes_sent; | |
103 | unsigned int bytes_received; | |
104 | unsigned int bytes_to_transfer; | |
105 | unsigned int words_to_transfer; | |
106 | unsigned int bytes_per_word; | |
83c624d8 | 107 | wait_queue_head_t wait; |
8dc4038a | 108 | u32 errors; |
83c624d8 | 109 | u32 status; |
a4f7ef6d FC |
110 | bool target_aborted; |
111 | bool use_ss_pin; | |
83c624d8 FC |
112 | }; |
113 | ||
83c624d8 FC |
114 | static void rzv2m_csi_reg_write_bit(const struct rzv2m_csi_priv *csi, |
115 | int reg_offs, int bit_mask, u32 value) | |
116 | { | |
117 | int nr_zeros; | |
118 | u32 tmp; | |
119 | ||
120 | nr_zeros = count_trailing_zeros(bit_mask); | |
121 | value <<= nr_zeros; | |
122 | ||
123 | tmp = (readl(csi->base + reg_offs) & ~bit_mask) | value; | |
124 | writel(tmp, csi->base + reg_offs); | |
125 | } | |
126 | ||
127 | static int rzv2m_csi_sw_reset(struct rzv2m_csi_priv *csi, int assert) | |
128 | { | |
129 | u32 reg; | |
130 | ||
131 | rzv2m_csi_reg_write_bit(csi, CSI_CNT, CSI_CNT_CSIRST, assert); | |
132 | ||
2ed2699f FC |
133 | if (!assert) |
134 | return 0; | |
83c624d8 | 135 | |
2ed2699f FC |
136 | return readl_poll_timeout(csi->base + CSI_MODE, reg, |
137 | !(reg & CSI_MODE_CSOT), 0, | |
138 | CSI_EN_DIS_TIMEOUT_US); | |
83c624d8 FC |
139 | } |
140 | ||
141 | static int rzv2m_csi_start_stop_operation(const struct rzv2m_csi_priv *csi, | |
142 | int enable, bool wait) | |
143 | { | |
144 | u32 reg; | |
145 | ||
146 | rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_CSIE, enable); | |
147 | ||
2ed2699f FC |
148 | if (enable || !wait) |
149 | return 0; | |
83c624d8 | 150 | |
2ed2699f FC |
151 | return readl_poll_timeout(csi->base + CSI_MODE, reg, |
152 | !(reg & CSI_MODE_CSOT), 0, | |
153 | CSI_EN_DIS_TIMEOUT_US); | |
83c624d8 FC |
154 | } |
155 | ||
156 | static int rzv2m_csi_fill_txfifo(struct rzv2m_csi_priv *csi) | |
157 | { | |
8dc4038a | 158 | unsigned int i; |
83c624d8 FC |
159 | |
160 | if (readl(csi->base + CSI_OFIFOL)) | |
161 | return -EIO; | |
162 | ||
163 | if (csi->bytes_per_word == 2) { | |
8dc4038a | 164 | const u16 *buf = csi->txbuf; |
83c624d8 FC |
165 | |
166 | for (i = 0; i < csi->words_to_transfer; i++) | |
167 | writel(buf[i], csi->base + CSI_OFIFO); | |
168 | } else { | |
8dc4038a | 169 | const u8 *buf = csi->txbuf; |
83c624d8 FC |
170 | |
171 | for (i = 0; i < csi->words_to_transfer; i++) | |
172 | writel(buf[i], csi->base + CSI_OFIFO); | |
173 | } | |
174 | ||
175 | csi->txbuf += csi->bytes_to_transfer; | |
176 | csi->bytes_sent += csi->bytes_to_transfer; | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | static int rzv2m_csi_read_rxfifo(struct rzv2m_csi_priv *csi) | |
182 | { | |
8dc4038a | 183 | unsigned int i; |
83c624d8 FC |
184 | |
185 | if (readl(csi->base + CSI_IFIFOL) != csi->bytes_to_transfer) | |
186 | return -EIO; | |
187 | ||
188 | if (csi->bytes_per_word == 2) { | |
8dc4038a | 189 | u16 *buf = csi->rxbuf; |
83c624d8 FC |
190 | |
191 | for (i = 0; i < csi->words_to_transfer; i++) | |
192 | buf[i] = (u16)readl(csi->base + CSI_IFIFO); | |
193 | } else { | |
8dc4038a | 194 | u8 *buf = csi->rxbuf; |
83c624d8 FC |
195 | |
196 | for (i = 0; i < csi->words_to_transfer; i++) | |
197 | buf[i] = (u8)readl(csi->base + CSI_IFIFO); | |
198 | } | |
199 | ||
200 | csi->rxbuf += csi->bytes_to_transfer; | |
201 | csi->bytes_received += csi->bytes_to_transfer; | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
a4f7ef6d FC |
206 | static inline void rzv2m_csi_empty_rxfifo(struct rzv2m_csi_priv *csi) |
207 | { | |
208 | unsigned int i; | |
209 | ||
210 | for (i = 0; i < csi->words_to_transfer; i++) | |
211 | readl(csi->base + CSI_IFIFO); | |
212 | } | |
213 | ||
83c624d8 FC |
214 | static inline void rzv2m_csi_calc_current_transfer(struct rzv2m_csi_priv *csi) |
215 | { | |
8dc4038a FC |
216 | unsigned int bytes_transferred = max(csi->bytes_received, csi->bytes_sent); |
217 | unsigned int bytes_remaining = csi->buffer_len - bytes_transferred; | |
218 | unsigned int to_transfer; | |
83c624d8 FC |
219 | |
220 | if (csi->txbuf) | |
221 | /* | |
222 | * Leaving a little bit of headroom in the FIFOs makes it very | |
223 | * hard to raise an overflow error (which is only possible | |
224 | * when IP transmits and receives at the same time). | |
225 | */ | |
8dc4038a | 226 | to_transfer = min(CSI_FIFO_HALF_SIZE, bytes_remaining); |
83c624d8 | 227 | else |
8dc4038a | 228 | to_transfer = min(CSI_FIFO_SIZE_BYTES, bytes_remaining); |
83c624d8 FC |
229 | |
230 | if (csi->bytes_per_word == 2) | |
231 | to_transfer >>= 1; | |
232 | ||
233 | /* | |
234 | * We can only choose a trigger level from a predefined set of values. | |
235 | * This will pick a value that is the greatest possible integer that's | |
236 | * less than or equal to the number of bytes we need to transfer. | |
237 | * This may result in multiple smaller transfers. | |
238 | */ | |
7b63568f | 239 | csi->words_to_transfer = rounddown_pow_of_two(to_transfer); |
83c624d8 FC |
240 | |
241 | if (csi->bytes_per_word == 2) | |
242 | csi->bytes_to_transfer = csi->words_to_transfer << 1; | |
243 | else | |
244 | csi->bytes_to_transfer = csi->words_to_transfer; | |
245 | } | |
246 | ||
247 | static inline void rzv2m_csi_set_rx_fifo_trigger_level(struct rzv2m_csi_priv *csi) | |
248 | { | |
249 | rzv2m_csi_reg_write_bit(csi, CSI_FIFOTRG, CSI_FIFOTRG_R_TRG, | |
7b63568f | 250 | ilog2(csi->words_to_transfer)); |
83c624d8 FC |
251 | } |
252 | ||
253 | static inline void rzv2m_csi_enable_rx_trigger(struct rzv2m_csi_priv *csi, | |
254 | bool enable) | |
255 | { | |
256 | rzv2m_csi_reg_write_bit(csi, CSI_CNT, CSI_CNT_R_TRGEN, enable); | |
257 | } | |
258 | ||
259 | static void rzv2m_csi_disable_irqs(const struct rzv2m_csi_priv *csi, | |
260 | u32 enable_bits) | |
261 | { | |
262 | u32 cnt = readl(csi->base + CSI_CNT); | |
263 | ||
264 | writel(cnt & ~enable_bits, csi->base + CSI_CNT); | |
265 | } | |
266 | ||
267 | static void rzv2m_csi_disable_all_irqs(struct rzv2m_csi_priv *csi) | |
268 | { | |
269 | rzv2m_csi_disable_irqs(csi, CSI_CNT_R_TRGR_E | CSI_CNT_T_TRGR_E | | |
270 | CSI_CNT_CSIEND_E | CSI_CNT_TREND_E | | |
271 | CSI_CNT_OVERF_E | CSI_CNT_UNDER_E); | |
272 | } | |
273 | ||
274 | static inline void rzv2m_csi_clear_irqs(struct rzv2m_csi_priv *csi, u32 irqs) | |
275 | { | |
276 | writel(irqs, csi->base + CSI_INT); | |
277 | } | |
278 | ||
279 | static void rzv2m_csi_clear_all_irqs(struct rzv2m_csi_priv *csi) | |
280 | { | |
281 | rzv2m_csi_clear_irqs(csi, CSI_INT_UNDER | CSI_INT_OVERF | | |
282 | CSI_INT_TREND | CSI_INT_CSIEND | CSI_INT_T_TRGR | | |
283 | CSI_INT_R_TRGR); | |
284 | } | |
285 | ||
286 | static void rzv2m_csi_enable_irqs(struct rzv2m_csi_priv *csi, u32 enable_bits) | |
287 | { | |
288 | u32 cnt = readl(csi->base + CSI_CNT); | |
289 | ||
290 | writel(cnt | enable_bits, csi->base + CSI_CNT); | |
291 | } | |
292 | ||
293 | static int rzv2m_csi_wait_for_interrupt(struct rzv2m_csi_priv *csi, | |
294 | u32 wait_mask, u32 enable_bits) | |
295 | { | |
296 | int ret; | |
297 | ||
298 | rzv2m_csi_enable_irqs(csi, enable_bits); | |
299 | ||
a4f7ef6d FC |
300 | if (spi_controller_is_target(csi->controller)) { |
301 | ret = wait_event_interruptible(csi->wait, | |
302 | ((csi->status & wait_mask) == wait_mask) || | |
303 | csi->errors || csi->target_aborted); | |
304 | if (ret || csi->target_aborted) | |
305 | ret = -EINTR; | |
306 | } else { | |
307 | ret = wait_event_timeout(csi->wait, | |
308 | ((csi->status & wait_mask) == wait_mask) || | |
309 | csi->errors, HZ) == 0 ? -ETIMEDOUT : 0; | |
310 | } | |
83c624d8 FC |
311 | |
312 | rzv2m_csi_disable_irqs(csi, enable_bits); | |
313 | ||
314 | if (csi->errors) | |
315 | return -EIO; | |
316 | ||
83c624d8 FC |
317 | return ret; |
318 | } | |
319 | ||
320 | static inline int rzv2m_csi_wait_for_rx_ready(struct rzv2m_csi_priv *csi) | |
321 | { | |
322 | int ret; | |
323 | ||
a4f7ef6d | 324 | if (readl(csi->base + CSI_IFIFOL) >= csi->bytes_to_transfer) |
83c624d8 FC |
325 | return 0; |
326 | ||
327 | ret = rzv2m_csi_wait_for_interrupt(csi, CSI_INT_R_TRGR, | |
328 | CSI_CNT_R_TRGR_E); | |
83c624d8 FC |
329 | if (ret == -ETIMEDOUT) |
330 | csi->errors |= RX_TIMEOUT_ERROR; | |
331 | ||
332 | return ret; | |
333 | } | |
334 | ||
335 | static irqreturn_t rzv2m_csi_irq_handler(int irq, void *data) | |
336 | { | |
8dc4038a | 337 | struct rzv2m_csi_priv *csi = data; |
83c624d8 FC |
338 | |
339 | csi->status = readl(csi->base + CSI_INT); | |
340 | rzv2m_csi_disable_irqs(csi, csi->status); | |
341 | ||
342 | if (csi->status & CSI_INT_OVERF) | |
343 | csi->errors |= OVERFLOW_ERROR; | |
344 | if (csi->status & CSI_INT_UNDER) | |
345 | csi->errors |= UNDERRUN_ERROR; | |
346 | ||
347 | wake_up(&csi->wait); | |
348 | ||
349 | return IRQ_HANDLED; | |
350 | } | |
351 | ||
352 | static void rzv2m_csi_setup_clock(struct rzv2m_csi_priv *csi, u32 spi_hz) | |
353 | { | |
354 | unsigned long csiclk_rate = clk_get_rate(csi->csiclk); | |
355 | unsigned long pclk_rate = clk_get_rate(csi->pclk); | |
356 | unsigned long csiclk_rate_limit = pclk_rate >> 1; | |
357 | u32 cks; | |
358 | ||
359 | /* | |
360 | * There is a restriction on the frequency of CSICLK, it has to be <= | |
361 | * PCLK / 2. | |
362 | */ | |
363 | if (csiclk_rate > csiclk_rate_limit) { | |
364 | clk_set_rate(csi->csiclk, csiclk_rate >> 1); | |
365 | csiclk_rate = clk_get_rate(csi->csiclk); | |
366 | } else if ((csiclk_rate << 1) <= csiclk_rate_limit) { | |
367 | clk_set_rate(csi->csiclk, csiclk_rate << 1); | |
368 | csiclk_rate = clk_get_rate(csi->csiclk); | |
369 | } | |
370 | ||
371 | spi_hz = spi_hz > CSI_MAX_SPI_SCKO ? CSI_MAX_SPI_SCKO : spi_hz; | |
372 | ||
373 | cks = DIV_ROUND_UP(csiclk_rate, spi_hz << 1); | |
374 | if (cks > CSI_CKS_MAX) | |
375 | cks = CSI_CKS_MAX; | |
376 | ||
377 | dev_dbg(csi->dev, "SPI clk rate is %ldHz\n", csiclk_rate / (cks << 1)); | |
378 | ||
379 | rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_CKS, cks); | |
380 | } | |
381 | ||
382 | static void rzv2m_csi_setup_operating_mode(struct rzv2m_csi_priv *csi, | |
383 | struct spi_transfer *t) | |
384 | { | |
385 | if (t->rx_buf && !t->tx_buf) | |
386 | /* Reception-only mode */ | |
387 | rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_TRMD, 0); | |
388 | else | |
389 | /* Send and receive mode */ | |
390 | rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_TRMD, 1); | |
391 | ||
392 | csi->bytes_per_word = t->bits_per_word / 8; | |
393 | rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_CCL, | |
394 | csi->bytes_per_word == 2); | |
395 | } | |
396 | ||
397 | static int rzv2m_csi_setup(struct spi_device *spi) | |
398 | { | |
399 | struct rzv2m_csi_priv *csi = spi_controller_get_devdata(spi->controller); | |
a4f7ef6d | 400 | u32 slave_selection = CSI_CLKSEL_SS_DISABLED; |
83c624d8 FC |
401 | int ret; |
402 | ||
403 | rzv2m_csi_sw_reset(csi, 0); | |
404 | ||
405 | writel(CSI_MODE_SETUP, csi->base + CSI_MODE); | |
406 | ||
407 | /* Setup clock polarity and phase timing */ | |
d5737d12 FC |
408 | rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_MODE, |
409 | ~spi->mode & SPI_MODE_X_MASK); | |
83c624d8 FC |
410 | |
411 | /* Setup serial data order */ | |
412 | rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_DIR, | |
413 | !!(spi->mode & SPI_LSB_FIRST)); | |
414 | ||
a4f7ef6d FC |
415 | /* Set the role, 1 for target and 0 for host */ |
416 | rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_SLAVE, | |
417 | !!spi_controller_is_target(csi->controller)); | |
418 | ||
419 | if (csi->use_ss_pin) | |
420 | slave_selection = spi->mode & SPI_CS_HIGH ? | |
421 | CSI_CLKSEL_SS_ENABLED_ACTIVE_HIGH : | |
422 | CSI_CLKSEL_SS_ENABLED_ACTIVE_LOW; | |
423 | ||
424 | /* Configure the slave selection (SS) pin */ | |
425 | rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_SS, slave_selection); | |
83c624d8 FC |
426 | |
427 | /* Give the IP a SW reset */ | |
428 | ret = rzv2m_csi_sw_reset(csi, 1); | |
429 | if (ret) | |
430 | return ret; | |
431 | rzv2m_csi_sw_reset(csi, 0); | |
432 | ||
433 | /* | |
434 | * We need to enable the communication so that the clock will settle | |
435 | * for the right polarity before enabling the CS. | |
436 | */ | |
437 | rzv2m_csi_start_stop_operation(csi, 1, false); | |
438 | udelay(10); | |
439 | rzv2m_csi_start_stop_operation(csi, 0, false); | |
440 | ||
441 | return 0; | |
442 | } | |
443 | ||
444 | static int rzv2m_csi_pio_transfer(struct rzv2m_csi_priv *csi) | |
445 | { | |
9f5ac599 FC |
446 | bool tx_completed = !csi->txbuf; |
447 | bool rx_completed = !csi->rxbuf; | |
83c624d8 FC |
448 | int ret = 0; |
449 | ||
450 | /* Make sure the TX FIFO is empty */ | |
451 | writel(0, csi->base + CSI_OFIFOL); | |
452 | ||
a4f7ef6d FC |
453 | /* Make sure the RX FIFO is empty */ |
454 | writel(0, csi->base + CSI_IFIFOL); | |
455 | ||
83c624d8 FC |
456 | csi->bytes_sent = 0; |
457 | csi->bytes_received = 0; | |
458 | csi->errors = 0; | |
a4f7ef6d | 459 | csi->target_aborted = false; |
83c624d8 FC |
460 | |
461 | rzv2m_csi_disable_all_irqs(csi); | |
462 | rzv2m_csi_clear_all_irqs(csi); | |
463 | rzv2m_csi_enable_rx_trigger(csi, true); | |
464 | ||
465 | while (!tx_completed || !rx_completed) { | |
466 | /* | |
467 | * Decide how many words we are going to transfer during | |
468 | * this cycle (for both TX and RX), then set the RX FIFO trigger | |
469 | * level accordingly. No need to set a trigger level for the | |
470 | * TX FIFO, as this IP comes with an interrupt that fires when | |
471 | * the TX FIFO is empty. | |
472 | */ | |
473 | rzv2m_csi_calc_current_transfer(csi); | |
474 | rzv2m_csi_set_rx_fifo_trigger_level(csi); | |
475 | ||
476 | rzv2m_csi_enable_irqs(csi, CSI_INT_OVERF | CSI_INT_UNDER); | |
477 | ||
83c624d8 FC |
478 | writel(readl(csi->base + CSI_INT), csi->base + CSI_INT); |
479 | csi->status = 0; | |
480 | ||
83c624d8 FC |
481 | /* TX */ |
482 | if (csi->txbuf) { | |
483 | ret = rzv2m_csi_fill_txfifo(csi); | |
484 | if (ret) | |
485 | break; | |
486 | ||
83c624d8 FC |
487 | if (csi->bytes_sent == csi->buffer_len) |
488 | tx_completed = true; | |
489 | } | |
490 | ||
a4f7ef6d FC |
491 | rzv2m_csi_start_stop_operation(csi, 1, false); |
492 | ||
83c624d8 FC |
493 | /* |
494 | * Make sure the RX FIFO contains the desired number of words. | |
495 | * We then either flush its content, or we copy it onto | |
496 | * csi->rxbuf. | |
497 | */ | |
498 | ret = rzv2m_csi_wait_for_rx_ready(csi); | |
499 | if (ret) | |
500 | break; | |
501 | ||
a4f7ef6d | 502 | if (!spi_controller_is_target(csi->controller)) |
83c624d8 FC |
503 | rzv2m_csi_start_stop_operation(csi, 0, false); |
504 | ||
a4f7ef6d FC |
505 | /* RX */ |
506 | if (csi->rxbuf) { | |
83c624d8 FC |
507 | ret = rzv2m_csi_read_rxfifo(csi); |
508 | if (ret) | |
509 | break; | |
510 | ||
511 | if (csi->bytes_received == csi->buffer_len) | |
512 | rx_completed = true; | |
a4f7ef6d FC |
513 | } else { |
514 | rzv2m_csi_empty_rxfifo(csi); | |
83c624d8 FC |
515 | } |
516 | ||
83c624d8 FC |
517 | if (csi->errors) { |
518 | ret = -EIO; | |
a4f7ef6d | 519 | break; |
83c624d8 FC |
520 | } |
521 | } | |
522 | ||
523 | rzv2m_csi_start_stop_operation(csi, 0, true); | |
83c624d8 FC |
524 | rzv2m_csi_disable_all_irqs(csi); |
525 | rzv2m_csi_enable_rx_trigger(csi, false); | |
526 | rzv2m_csi_clear_all_irqs(csi); | |
527 | ||
528 | return ret; | |
529 | } | |
530 | ||
531 | static int rzv2m_csi_transfer_one(struct spi_controller *controller, | |
532 | struct spi_device *spi, | |
533 | struct spi_transfer *transfer) | |
534 | { | |
535 | struct rzv2m_csi_priv *csi = spi_controller_get_devdata(controller); | |
536 | struct device *dev = csi->dev; | |
537 | int ret; | |
538 | ||
539 | csi->txbuf = transfer->tx_buf; | |
540 | csi->rxbuf = transfer->rx_buf; | |
541 | csi->buffer_len = transfer->len; | |
542 | ||
543 | rzv2m_csi_setup_operating_mode(csi, transfer); | |
544 | ||
a4f7ef6d FC |
545 | if (!spi_controller_is_target(csi->controller)) |
546 | rzv2m_csi_setup_clock(csi, transfer->speed_hz); | |
83c624d8 FC |
547 | |
548 | ret = rzv2m_csi_pio_transfer(csi); | |
549 | if (ret) { | |
550 | if (csi->errors & UNDERRUN_ERROR) | |
551 | dev_err(dev, "Underrun error\n"); | |
552 | if (csi->errors & OVERFLOW_ERROR) | |
553 | dev_err(dev, "Overflow error\n"); | |
554 | if (csi->errors & TX_TIMEOUT_ERROR) | |
555 | dev_err(dev, "TX timeout error\n"); | |
556 | if (csi->errors & RX_TIMEOUT_ERROR) | |
557 | dev_err(dev, "RX timeout error\n"); | |
558 | } | |
559 | ||
560 | return ret; | |
561 | } | |
562 | ||
a4f7ef6d FC |
563 | static int rzv2m_csi_target_abort(struct spi_controller *ctlr) |
564 | { | |
565 | struct rzv2m_csi_priv *csi = spi_controller_get_devdata(ctlr); | |
566 | ||
567 | csi->target_aborted = true; | |
568 | wake_up(&csi->wait); | |
569 | ||
570 | return 0; | |
571 | } | |
572 | ||
83c624d8 FC |
573 | static int rzv2m_csi_probe(struct platform_device *pdev) |
574 | { | |
a4f7ef6d | 575 | struct device_node *np = pdev->dev.of_node; |
83c624d8 FC |
576 | struct spi_controller *controller; |
577 | struct device *dev = &pdev->dev; | |
578 | struct rzv2m_csi_priv *csi; | |
579 | struct reset_control *rstc; | |
a4f7ef6d | 580 | bool target_mode; |
83c624d8 FC |
581 | int irq; |
582 | int ret; | |
583 | ||
a4f7ef6d FC |
584 | target_mode = of_property_read_bool(np, "spi-slave"); |
585 | ||
586 | if (target_mode) | |
587 | controller = devm_spi_alloc_target(dev, sizeof(*csi)); | |
588 | else | |
589 | controller = devm_spi_alloc_host(dev, sizeof(*csi)); | |
590 | ||
83c624d8 FC |
591 | if (!controller) |
592 | return -ENOMEM; | |
593 | ||
594 | csi = spi_controller_get_devdata(controller); | |
595 | platform_set_drvdata(pdev, csi); | |
596 | ||
a4f7ef6d FC |
597 | csi->use_ss_pin = false; |
598 | if (spi_controller_is_target(controller) && | |
599 | !of_property_read_bool(np, "renesas,csi-no-ss")) | |
600 | csi->use_ss_pin = true; | |
601 | ||
83c624d8 FC |
602 | csi->dev = dev; |
603 | csi->controller = controller; | |
a4f7ef6d | 604 | csi->target_aborted = false; |
83c624d8 FC |
605 | |
606 | csi->base = devm_platform_ioremap_resource(pdev, 0); | |
607 | if (IS_ERR(csi->base)) | |
608 | return PTR_ERR(csi->base); | |
609 | ||
610 | irq = platform_get_irq(pdev, 0); | |
611 | if (irq < 0) | |
612 | return irq; | |
613 | ||
614 | csi->csiclk = devm_clk_get(dev, "csiclk"); | |
615 | if (IS_ERR(csi->csiclk)) | |
616 | return dev_err_probe(dev, PTR_ERR(csi->csiclk), | |
617 | "could not get csiclk\n"); | |
618 | ||
619 | csi->pclk = devm_clk_get(dev, "pclk"); | |
620 | if (IS_ERR(csi->pclk)) | |
621 | return dev_err_probe(dev, PTR_ERR(csi->pclk), | |
622 | "could not get pclk\n"); | |
623 | ||
624 | rstc = devm_reset_control_get_shared(dev, NULL); | |
625 | if (IS_ERR(rstc)) | |
626 | return dev_err_probe(dev, PTR_ERR(rstc), "Missing reset ctrl\n"); | |
627 | ||
628 | init_waitqueue_head(&csi->wait); | |
629 | ||
a4f7ef6d | 630 | controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH; |
83c624d8 FC |
631 | controller->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8); |
632 | controller->setup = rzv2m_csi_setup; | |
633 | controller->transfer_one = rzv2m_csi_transfer_one; | |
634 | controller->use_gpio_descriptors = true; | |
a4f7ef6d | 635 | controller->target_abort = rzv2m_csi_target_abort; |
83c624d8 | 636 | |
c5a7b668 FC |
637 | device_set_node(&controller->dev, dev_fwnode(dev)); |
638 | ||
83c624d8 FC |
639 | ret = devm_request_irq(dev, irq, rzv2m_csi_irq_handler, 0, |
640 | dev_name(dev), csi); | |
641 | if (ret) | |
642 | return dev_err_probe(dev, ret, "cannot request IRQ\n"); | |
643 | ||
644 | /* | |
645 | * The reset also affects other HW that is not under the control | |
646 | * of Linux. Therefore, all we can do is make sure the reset is | |
647 | * deasserted. | |
648 | */ | |
649 | reset_control_deassert(rstc); | |
650 | ||
651 | /* Make sure the IP is in SW reset state */ | |
652 | ret = rzv2m_csi_sw_reset(csi, 1); | |
653 | if (ret) | |
654 | return ret; | |
655 | ||
656 | ret = clk_prepare_enable(csi->csiclk); | |
657 | if (ret) | |
658 | return dev_err_probe(dev, ret, "could not enable csiclk\n"); | |
659 | ||
660 | ret = spi_register_controller(controller); | |
661 | if (ret) { | |
662 | clk_disable_unprepare(csi->csiclk); | |
663 | return dev_err_probe(dev, ret, "register controller failed\n"); | |
664 | } | |
665 | ||
666 | return 0; | |
667 | } | |
668 | ||
93033314 | 669 | static void rzv2m_csi_remove(struct platform_device *pdev) |
83c624d8 FC |
670 | { |
671 | struct rzv2m_csi_priv *csi = platform_get_drvdata(pdev); | |
672 | ||
673 | spi_unregister_controller(csi->controller); | |
674 | rzv2m_csi_sw_reset(csi, 1); | |
675 | clk_disable_unprepare(csi->csiclk); | |
83c624d8 FC |
676 | } |
677 | ||
678 | static const struct of_device_id rzv2m_csi_match[] = { | |
679 | { .compatible = "renesas,rzv2m-csi" }, | |
680 | { /* sentinel */ } | |
681 | }; | |
682 | MODULE_DEVICE_TABLE(of, rzv2m_csi_match); | |
683 | ||
684 | static struct platform_driver rzv2m_csi_drv = { | |
685 | .probe = rzv2m_csi_probe, | |
93033314 | 686 | .remove_new = rzv2m_csi_remove, |
83c624d8 FC |
687 | .driver = { |
688 | .name = "rzv2m_csi", | |
689 | .of_match_table = rzv2m_csi_match, | |
690 | }, | |
691 | }; | |
692 | module_platform_driver(rzv2m_csi_drv); | |
693 | ||
694 | MODULE_LICENSE("GPL"); | |
695 | MODULE_AUTHOR("Fabrizio Castro <[email protected]>"); | |
696 | MODULE_DESCRIPTION("Clocked Serial Interface Driver"); |