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Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +02001/*
2 * Copyright (C) 2007 Atmel Corporation
3 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02004 * SPDX-License-Identifier: GPL-2.0+
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +02005 */
6#include <common.h>
Wenyou Yang0eafd4b2016-10-28 14:17:49 +08007#include <clk.h>
8#include <dm.h>
9#include <fdtdec.h>
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020010#include <spi.h>
11#include <malloc.h>
Wenyou Yang0eafd4b2016-10-28 14:17:49 +080012#include <wait_bit.h>
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020013
14#include <asm/io.h>
15
16#include <asm/arch/clk.h>
Reinhard Meyer329f0f52010-11-03 16:32:56 +010017#include <asm/arch/hardware.h>
Wenyou Yang0eafd4b2016-10-28 14:17:49 +080018#ifdef CONFIG_DM_SPI
19#include <asm/arch/at91_spi.h>
20#endif
21#ifdef CONFIG_DM_GPIO
22#include <asm/gpio.h>
23#endif
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020024
25#include "atmel_spi.h"
26
Wenyou Yang0eafd4b2016-10-28 14:17:49 +080027DECLARE_GLOBAL_DATA_PTR;
28
29#ifndef CONFIG_DM_SPI
30
Bo Shene0d2d3b2013-04-16 23:42:42 +000031static int spi_has_wdrbt(struct atmel_spi_slave *slave)
32{
33 unsigned int ver;
34
35 ver = spi_readl(slave, VERSION);
36
37 return (ATMEL_SPI_VERSION_REV(ver) >= 0x210);
38}
39
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020040void spi_init()
41{
42
43}
44
45struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
46 unsigned int max_hz, unsigned int mode)
47{
48 struct atmel_spi_slave *as;
49 unsigned int scbr;
50 u32 csrx;
51 void *regs;
52
Reinhard Meyerf09d3b22010-08-09 13:37:59 +020053 if (!spi_cs_is_valid(bus, cs))
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020054 return NULL;
55
56 switch (bus) {
57 case 0:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010058 regs = (void *)ATMEL_BASE_SPI0;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020059 break;
Reinhard Meyer329f0f52010-11-03 16:32:56 +010060#ifdef ATMEL_BASE_SPI1
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020061 case 1:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010062 regs = (void *)ATMEL_BASE_SPI1;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020063 break;
64#endif
Reinhard Meyer329f0f52010-11-03 16:32:56 +010065#ifdef ATMEL_BASE_SPI2
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020066 case 2:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010067 regs = (void *)ATMEL_BASE_SPI2;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020068 break;
69#endif
Reinhard Meyer329f0f52010-11-03 16:32:56 +010070#ifdef ATMEL_BASE_SPI3
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020071 case 3:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010072 regs = (void *)ATMEL_BASE_SPI3;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020073 break;
74#endif
75 default:
76 return NULL;
77 }
78
79
80 scbr = (get_spi_clk_rate(bus) + max_hz - 1) / max_hz;
81 if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
82 /* Too low max SCK rate */
83 return NULL;
84 if (scbr < 1)
85 scbr = 1;
86
87 csrx = ATMEL_SPI_CSRx_SCBR(scbr);
88 csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
89 if (!(mode & SPI_CPHA))
90 csrx |= ATMEL_SPI_CSRx_NCPHA;
91 if (mode & SPI_CPOL)
92 csrx |= ATMEL_SPI_CSRx_CPOL;
93
Simon Glassd3504fe2013-03-18 19:23:40 +000094 as = spi_alloc_slave(struct atmel_spi_slave, bus, cs);
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020095 if (!as)
96 return NULL;
97
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020098 as->regs = regs;
99 as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
100 | ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
Bo Shene0d2d3b2013-04-16 23:42:42 +0000101 if (spi_has_wdrbt(as))
102 as->mr |= ATMEL_SPI_MR_WDRBT;
103
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200104 spi_writel(as, CSR(cs), csrx);
105
106 return &as->slave;
107}
108
109void spi_free_slave(struct spi_slave *slave)
110{
111 struct atmel_spi_slave *as = to_atmel_spi(slave);
112
113 free(as);
114}
115
116int spi_claim_bus(struct spi_slave *slave)
117{
118 struct atmel_spi_slave *as = to_atmel_spi(slave);
119
120 /* Enable the SPI hardware */
121 spi_writel(as, CR, ATMEL_SPI_CR_SPIEN);
122
123 /*
124 * Select the slave. This should set SCK to the correct
125 * initial state, etc.
126 */
127 spi_writel(as, MR, as->mr);
128
129 return 0;
130}
131
132void spi_release_bus(struct spi_slave *slave)
133{
134 struct atmel_spi_slave *as = to_atmel_spi(slave);
135
136 /* Disable the SPI hardware */
137 spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS);
138}
139
140int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
141 const void *dout, void *din, unsigned long flags)
142{
143 struct atmel_spi_slave *as = to_atmel_spi(slave);
144 unsigned int len_tx;
145 unsigned int len_rx;
146 unsigned int len;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200147 u32 status;
148 const u8 *txp = dout;
149 u8 *rxp = din;
150 u8 value;
151
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200152 if (bitlen == 0)
153 /* Finish any previously submitted transfers */
154 goto out;
155
156 /*
157 * TODO: The controller can do non-multiple-of-8 bit
158 * transfers, but this driver currently doesn't support it.
159 *
160 * It's also not clear how such transfers are supposed to be
161 * represented as a stream of bytes...this is a limitation of
162 * the current SPI interface.
163 */
164 if (bitlen % 8) {
165 /* Errors always terminate an ongoing transfer */
166 flags |= SPI_XFER_END;
167 goto out;
168 }
169
170 len = bitlen / 8;
171
172 /*
173 * The controller can do automatic CS control, but it is
174 * somewhat quirky, and it doesn't really buy us much anyway
175 * in the context of U-Boot.
176 */
Reinhard Meyerf09d3b22010-08-09 13:37:59 +0200177 if (flags & SPI_XFER_BEGIN) {
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200178 spi_cs_activate(slave);
Reinhard Meyerf09d3b22010-08-09 13:37:59 +0200179 /*
180 * sometimes the RDR is not empty when we get here,
181 * in theory that should not happen, but it DOES happen.
182 * Read it here to be on the safe side.
183 * That also clears the OVRES flag. Required if the
184 * following loop exits due to OVRES!
185 */
186 spi_readl(as, RDR);
187 }
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200188
189 for (len_tx = 0, len_rx = 0; len_rx < len; ) {
190 status = spi_readl(as, SR);
191
192 if (status & ATMEL_SPI_SR_OVRES)
193 return -1;
194
195 if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
196 if (txp)
197 value = *txp++;
198 else
199 value = 0;
200 spi_writel(as, TDR, value);
201 len_tx++;
202 }
203 if (status & ATMEL_SPI_SR_RDRF) {
204 value = spi_readl(as, RDR);
205 if (rxp)
206 *rxp++ = value;
207 len_rx++;
208 }
209 }
210
211out:
212 if (flags & SPI_XFER_END) {
213 /*
214 * Wait until the transfer is completely done before
215 * we deactivate CS.
216 */
217 do {
218 status = spi_readl(as, SR);
219 } while (!(status & ATMEL_SPI_SR_TXEMPTY));
220
221 spi_cs_deactivate(slave);
222 }
223
224 return 0;
225}
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800226
227#else
228
229#define MAX_CS_COUNT 4
230
231struct atmel_spi_platdata {
232 struct at91_spi *regs;
233};
234
235struct atmel_spi_priv {
236 unsigned int freq; /* Default frequency */
237 unsigned int mode;
238 ulong bus_clk_rate;
239 struct gpio_desc cs_gpios[MAX_CS_COUNT];
240};
241
242static int atmel_spi_claim_bus(struct udevice *dev)
243{
244 struct udevice *bus = dev_get_parent(dev);
245 struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
246 struct atmel_spi_priv *priv = dev_get_priv(bus);
247 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
248 struct at91_spi *reg_base = bus_plat->regs;
249 u32 cs = slave_plat->cs;
250 u32 freq = priv->freq;
251 u32 scbr, csrx, mode;
252
253 scbr = (priv->bus_clk_rate + freq - 1) / freq;
254 if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
255 return -EINVAL;
256
257 if (scbr < 1)
258 scbr = 1;
259
260 csrx = ATMEL_SPI_CSRx_SCBR(scbr);
261 csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
262
263 if (!(priv->mode & SPI_CPHA))
264 csrx |= ATMEL_SPI_CSRx_NCPHA;
265 if (priv->mode & SPI_CPOL)
266 csrx |= ATMEL_SPI_CSRx_CPOL;
267
268 writel(csrx, &reg_base->csr[cs]);
269
270 mode = ATMEL_SPI_MR_MSTR |
271 ATMEL_SPI_MR_MODFDIS |
272 ATMEL_SPI_MR_WDRBT |
273 ATMEL_SPI_MR_PCS(~(1 << cs));
274
275 writel(mode, &reg_base->mr);
276
277 writel(ATMEL_SPI_CR_SPIEN, &reg_base->cr);
278
279 return 0;
280}
281
282static int atmel_spi_release_bus(struct udevice *dev)
283{
284 struct udevice *bus = dev_get_parent(dev);
285 struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
286
287 writel(ATMEL_SPI_CR_SPIDIS, &bus_plat->regs->cr);
288
289 return 0;
290}
291
292static void atmel_spi_cs_activate(struct udevice *dev)
293{
294 struct udevice *bus = dev_get_parent(dev);
295 struct atmel_spi_priv *priv = dev_get_priv(bus);
296 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
297 u32 cs = slave_plat->cs;
298
Wenyou Yang61a77ce2017-04-07 15:14:46 +0800299 if (!dm_gpio_is_valid(&priv->cs_gpios[cs]))
300 return;
301
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800302 dm_gpio_set_value(&priv->cs_gpios[cs], 0);
303}
304
305static void atmel_spi_cs_deactivate(struct udevice *dev)
306{
307 struct udevice *bus = dev_get_parent(dev);
308 struct atmel_spi_priv *priv = dev_get_priv(bus);
309 struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
310 u32 cs = slave_plat->cs;
311
Wenyou Yang61a77ce2017-04-07 15:14:46 +0800312 if (!dm_gpio_is_valid(&priv->cs_gpios[cs]))
313 return;
314
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800315 dm_gpio_set_value(&priv->cs_gpios[cs], 1);
316}
317
318static int atmel_spi_xfer(struct udevice *dev, unsigned int bitlen,
319 const void *dout, void *din, unsigned long flags)
320{
321 struct udevice *bus = dev_get_parent(dev);
322 struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
323 struct at91_spi *reg_base = bus_plat->regs;
324
325 u32 len_tx, len_rx, len;
326 u32 status;
327 const u8 *txp = dout;
328 u8 *rxp = din;
329 u8 value;
330
331 if (bitlen == 0)
332 goto out;
333
334 /*
335 * The controller can do non-multiple-of-8 bit
336 * transfers, but this driver currently doesn't support it.
337 *
338 * It's also not clear how such transfers are supposed to be
339 * represented as a stream of bytes...this is a limitation of
340 * the current SPI interface.
341 */
342 if (bitlen % 8) {
343 /* Errors always terminate an ongoing transfer */
344 flags |= SPI_XFER_END;
345 goto out;
346 }
347
348 len = bitlen / 8;
349
350 /*
351 * The controller can do automatic CS control, but it is
352 * somewhat quirky, and it doesn't really buy us much anyway
353 * in the context of U-Boot.
354 */
355 if (flags & SPI_XFER_BEGIN) {
356 atmel_spi_cs_activate(dev);
357
358 /*
359 * sometimes the RDR is not empty when we get here,
360 * in theory that should not happen, but it DOES happen.
361 * Read it here to be on the safe side.
362 * That also clears the OVRES flag. Required if the
363 * following loop exits due to OVRES!
364 */
365 readl(&reg_base->rdr);
366 }
367
368 for (len_tx = 0, len_rx = 0; len_rx < len; ) {
369 status = readl(&reg_base->sr);
370
371 if (status & ATMEL_SPI_SR_OVRES)
372 return -1;
373
374 if ((len_tx < len) && (status & ATMEL_SPI_SR_TDRE)) {
375 if (txp)
376 value = *txp++;
377 else
378 value = 0;
379 writel(value, &reg_base->tdr);
380 len_tx++;
381 }
382
383 if (status & ATMEL_SPI_SR_RDRF) {
384 value = readl(&reg_base->rdr);
385 if (rxp)
386 *rxp++ = value;
387 len_rx++;
388 }
389 }
390
391out:
392 if (flags & SPI_XFER_END) {
393 /*
394 * Wait until the transfer is completely done before
395 * we deactivate CS.
396 */
Álvaro Fernández Rojas48263502018-01-23 17:14:55 +0100397 wait_for_bit_le32(&reg_base->sr,
398 ATMEL_SPI_SR_TXEMPTY, true, 1000, false);
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800399
400 atmel_spi_cs_deactivate(dev);
401 }
402
403 return 0;
404}
405
406static int atmel_spi_set_speed(struct udevice *bus, uint speed)
407{
408 struct atmel_spi_priv *priv = dev_get_priv(bus);
409
410 priv->freq = speed;
411
412 return 0;
413}
414
415static int atmel_spi_set_mode(struct udevice *bus, uint mode)
416{
417 struct atmel_spi_priv *priv = dev_get_priv(bus);
418
419 priv->mode = mode;
420
421 return 0;
422}
423
424static const struct dm_spi_ops atmel_spi_ops = {
425 .claim_bus = atmel_spi_claim_bus,
426 .release_bus = atmel_spi_release_bus,
427 .xfer = atmel_spi_xfer,
428 .set_speed = atmel_spi_set_speed,
429 .set_mode = atmel_spi_set_mode,
430 /*
431 * cs_info is not needed, since we require all chip selects to be
432 * in the device tree explicitly
433 */
434};
435
436static int atmel_spi_enable_clk(struct udevice *bus)
437{
438 struct atmel_spi_priv *priv = dev_get_priv(bus);
439 struct clk clk;
440 ulong clk_rate;
441 int ret;
442
443 ret = clk_get_by_index(bus, 0, &clk);
444 if (ret)
445 return -EINVAL;
446
447 ret = clk_enable(&clk);
448 if (ret)
449 return ret;
450
451 clk_rate = clk_get_rate(&clk);
452 if (!clk_rate)
453 return -EINVAL;
454
455 priv->bus_clk_rate = clk_rate;
456
457 clk_free(&clk);
458
459 return 0;
460}
461
462static int atmel_spi_probe(struct udevice *bus)
463{
464 struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
465 struct atmel_spi_priv *priv = dev_get_priv(bus);
466 int i, ret;
467
468 ret = atmel_spi_enable_clk(bus);
469 if (ret)
470 return ret;
471
Simon Glassa821c4a2017-05-17 17:18:05 -0600472 bus_plat->regs = (struct at91_spi *)devfdt_get_addr(bus);
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800473
474 ret = gpio_request_list_by_name(bus, "cs-gpios", priv->cs_gpios,
475 ARRAY_SIZE(priv->cs_gpios), 0);
476 if (ret < 0) {
Masahiro Yamada9b643e32017-09-16 14:10:41 +0900477 pr_err("Can't get %s gpios! Error: %d", bus->name, ret);
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800478 return ret;
479 }
480
481 for(i = 0; i < ARRAY_SIZE(priv->cs_gpios); i++) {
Wenyou Yang61a77ce2017-04-07 15:14:46 +0800482 if (!dm_gpio_is_valid(&priv->cs_gpios[i]))
483 continue;
484
Wenyou Yang0eafd4b2016-10-28 14:17:49 +0800485 dm_gpio_set_dir_flags(&priv->cs_gpios[i],
486 GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
487 }
488
489 writel(ATMEL_SPI_CR_SWRST, &bus_plat->regs->cr);
490
491 return 0;
492}
493
494static const struct udevice_id atmel_spi_ids[] = {
495 { .compatible = "atmel,at91rm9200-spi" },
496 { }
497};
498
499U_BOOT_DRIVER(atmel_spi) = {
500 .name = "atmel_spi",
501 .id = UCLASS_SPI,
502 .of_match = atmel_spi_ids,
503 .ops = &atmel_spi_ops,
504 .platdata_auto_alloc_size = sizeof(struct atmel_spi_platdata),
505 .priv_auto_alloc_size = sizeof(struct atmel_spi_priv),
506 .probe = atmel_spi_probe,
507};
508#endif