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1/*
2 * Marvell Orion SPI controller driver
3 *
4 * Author: Shadi Ammouri <shadi@marvell.com>
5 * Copyright (C) 2007-2008 Marvell Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/delay.h>
15#include <linux/platform_device.h>
16#include <linux/err.h>
17#include <linux/io.h>
18#include <linux/spi/spi.h>
19#include <linux/module.h>
20#include <linux/clk.h>
21#include <asm/unaligned.h>
22
23#define DRIVER_NAME "orion_spi"
24
25#define ORION_NUM_CHIPSELECTS 1 /* only one slave is supported*/
26#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
27
28#define ORION_SPI_IF_CTRL_REG 0x00
29#define ORION_SPI_IF_CONFIG_REG 0x04
30#define ORION_SPI_DATA_OUT_REG 0x08
31#define ORION_SPI_DATA_IN_REG 0x0c
32#define ORION_SPI_INT_CAUSE_REG 0x10
33
34#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
35#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
36
37struct orion_spi {
38 struct work_struct work;
39
40 /* Lock access to transfer list. */
41 spinlock_t lock;
42
43 struct list_head msg_queue;
44 struct spi_master *master;
45 void __iomem *base;
46 unsigned int max_speed;
47 unsigned int min_speed;
48 struct orion_spi_info *spi_info;
49 struct clk *clk;
50};
51
52static struct workqueue_struct *orion_spi_wq;
53
54static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
55{
56 return orion_spi->base + reg;
57}
58
59static inline void
60orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
61{
62 void __iomem *reg_addr = spi_reg(orion_spi, reg);
63 u32 val;
64
65 val = readl(reg_addr);
66 val |= mask;
67 writel(val, reg_addr);
68}
69
70static inline void
71orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
72{
73 void __iomem *reg_addr = spi_reg(orion_spi, reg);
74 u32 val;
75
76 val = readl(reg_addr);
77 val &= ~mask;
78 writel(val, reg_addr);
79}
80
81static int orion_spi_set_transfer_size(struct orion_spi *orion_spi, int size)
82{
83 if (size == 16) {
84 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
85 ORION_SPI_IF_8_16_BIT_MODE);
86 } else if (size == 8) {
87 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
88 ORION_SPI_IF_8_16_BIT_MODE);
89 } else {
90 pr_debug("Bad bits per word value %d (only 8 or 16 are "
91 "allowed).\n", size);
92 return -EINVAL;
93 }
94
95 return 0;
96}
97
98static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
99{
100 u32 tclk_hz;
101 u32 rate;
102 u32 prescale;
103 u32 reg;
104 struct orion_spi *orion_spi;
105
106 orion_spi = spi_master_get_devdata(spi->master);
107
108 tclk_hz = clk_get_rate(orion_spi->clk);
109
110 /*
111 * the supported rates are: 4,6,8...30
112 * round up as we look for equal or less speed
113 */
114 rate = DIV_ROUND_UP(tclk_hz, speed);
115 rate = roundup(rate, 2);
116
117 /* check if requested speed is too small */
118 if (rate > 30)
119 return -EINVAL;
120
121 if (rate < 4)
122 rate = 4;
123
124 /* Convert the rate to SPI clock divisor value. */
125 prescale = 0x10 + rate/2;
126
127 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
128 reg = ((reg & ~ORION_SPI_CLK_PRESCALE_MASK) | prescale);
129 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
130
131 return 0;
132}
133
134/*
135 * called only when no transfer is active on the bus
136 */
137static int
138orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
139{
140 struct orion_spi *orion_spi;
141 unsigned int speed = spi->max_speed_hz;
142 unsigned int bits_per_word = spi->bits_per_word;
143 int rc;
144
145 orion_spi = spi_master_get_devdata(spi->master);
146
147 if ((t != NULL) && t->speed_hz)
148 speed = t->speed_hz;
149
150 if ((t != NULL) && t->bits_per_word)
151 bits_per_word = t->bits_per_word;
152
153 rc = orion_spi_baudrate_set(spi, speed);
154 if (rc)
155 return rc;
156
157 return orion_spi_set_transfer_size(orion_spi, bits_per_word);
158}
159
160static void orion_spi_set_cs(struct orion_spi *orion_spi, int enable)
161{
162 if (enable)
163 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
164 else
165 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
166}
167
168static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
169{
170 int i;
171
172 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
173 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
174 return 1;
175 else
176 udelay(1);
177 }
178
179 return -1;
180}
181
182static inline int
183orion_spi_write_read_8bit(struct spi_device *spi,
184 const u8 **tx_buf, u8 **rx_buf)
185{
186 void __iomem *tx_reg, *rx_reg, *int_reg;
187 struct orion_spi *orion_spi;
188
189 orion_spi = spi_master_get_devdata(spi->master);
190 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
191 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
192 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
193
194 /* clear the interrupt cause register */
195 writel(0x0, int_reg);
196
197 if (tx_buf && *tx_buf)
198 writel(*(*tx_buf)++, tx_reg);
199 else
200 writel(0, tx_reg);
201
202 if (orion_spi_wait_till_ready(orion_spi) < 0) {
203 dev_err(&spi->dev, "TXS timed out\n");
204 return -1;
205 }
206
207 if (rx_buf && *rx_buf)
208 *(*rx_buf)++ = readl(rx_reg);
209
210 return 1;
211}
212
213static inline int
214orion_spi_write_read_16bit(struct spi_device *spi,
215 const u16 **tx_buf, u16 **rx_buf)
216{
217 void __iomem *tx_reg, *rx_reg, *int_reg;
218 struct orion_spi *orion_spi;
219
220 orion_spi = spi_master_get_devdata(spi->master);
221 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
222 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
223 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
224
225 /* clear the interrupt cause register */
226 writel(0x0, int_reg);
227
228 if (tx_buf && *tx_buf)
229 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
230 else
231 writel(0, tx_reg);
232
233 if (orion_spi_wait_till_ready(orion_spi) < 0) {
234 dev_err(&spi->dev, "TXS timed out\n");
235 return -1;
236 }
237
238 if (rx_buf && *rx_buf)
239 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
240
241 return 1;
242}
243
244static unsigned int
245orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
246{
247 struct orion_spi *orion_spi;
248 unsigned int count;
249 int word_len;
250
251 orion_spi = spi_master_get_devdata(spi->master);
252 word_len = spi->bits_per_word;
253 count = xfer->len;
254
255 if (word_len == 8) {
256 const u8 *tx = xfer->tx_buf;
257 u8 *rx = xfer->rx_buf;
258
259 do {
260 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
261 goto out;
262 count--;
263 } while (count);
264 } else if (word_len == 16) {
265 const u16 *tx = xfer->tx_buf;
266 u16 *rx = xfer->rx_buf;
267
268 do {
269 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
270 goto out;
271 count -= 2;
272 } while (count);
273 }
274
275out:
276 return xfer->len - count;
277}
278
279
280static void orion_spi_work(struct work_struct *work)
281{
282 struct orion_spi *orion_spi =
283 container_of(work, struct orion_spi, work);
284
285 spin_lock_irq(&orion_spi->lock);
286 while (!list_empty(&orion_spi->msg_queue)) {
287 struct spi_message *m;
288 struct spi_device *spi;
289 struct spi_transfer *t = NULL;
290 int par_override = 0;
291 int status = 0;
292 int cs_active = 0;
293
294 m = container_of(orion_spi->msg_queue.next, struct spi_message,
295 queue);
296
297 list_del_init(&m->queue);
298 spin_unlock_irq(&orion_spi->lock);
299
300 spi = m->spi;
301
302 /* Load defaults */
303 status = orion_spi_setup_transfer(spi, NULL);
304
305 if (status < 0)
306 goto msg_done;
307
308 list_for_each_entry(t, &m->transfers, transfer_list) {
309 if (par_override || t->speed_hz || t->bits_per_word) {
310 par_override = 1;
311 status = orion_spi_setup_transfer(spi, t);
312 if (status < 0)
313 break;
314 if (!t->speed_hz && !t->bits_per_word)
315 par_override = 0;
316 }
317
318 if (!cs_active) {
319 orion_spi_set_cs(orion_spi, 1);
320 cs_active = 1;
321 }
322
323 if (t->len)
324 m->actual_length +=
325 orion_spi_write_read(spi, t);
326
327 if (t->delay_usecs)
328 udelay(t->delay_usecs);
329
330 if (t->cs_change) {
331 orion_spi_set_cs(orion_spi, 0);
332 cs_active = 0;
333 }
334 }
335
336msg_done:
337 if (cs_active)
338 orion_spi_set_cs(orion_spi, 0);
339
340 m->status = status;
341 m->complete(m->context);
342
343 spin_lock_irq(&orion_spi->lock);
344 }
345
346 spin_unlock_irq(&orion_spi->lock);
347}
348
349static int __init orion_spi_reset(struct orion_spi *orion_spi)
350{
351 /* Verify that the CS is deasserted */
352 orion_spi_set_cs(orion_spi, 0);
353
354 return 0;
355}
356
357static int orion_spi_setup(struct spi_device *spi)
358{
359 struct orion_spi *orion_spi;
360
361 orion_spi = spi_master_get_devdata(spi->master);
362
363 if ((spi->max_speed_hz == 0)
364 || (spi->max_speed_hz > orion_spi->max_speed))
365 spi->max_speed_hz = orion_spi->max_speed;
366
367 if (spi->max_speed_hz < orion_spi->min_speed) {
368 dev_err(&spi->dev, "setup: requested speed too low %d Hz\n",
369 spi->max_speed_hz);
370 return -EINVAL;
371 }
372
373 /*
374 * baudrate & width will be set orion_spi_setup_transfer
375 */
376 return 0;
377}
378
379static int orion_spi_transfer(struct spi_device *spi, struct spi_message *m)
380{
381 struct orion_spi *orion_spi;
382 struct spi_transfer *t = NULL;
383 unsigned long flags;
384
385 m->actual_length = 0;
386 m->status = 0;
387
388 /* reject invalid messages and transfers */
389 if (list_empty(&m->transfers) || !m->complete)
390 return -EINVAL;
391
392 orion_spi = spi_master_get_devdata(spi->master);
393
394 list_for_each_entry(t, &m->transfers, transfer_list) {
395 unsigned int bits_per_word = spi->bits_per_word;
396
397 if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
398 dev_err(&spi->dev,
399 "message rejected : "
400 "invalid transfer data buffers\n");
401 goto msg_rejected;
402 }
403
404 if (t->bits_per_word)
405 bits_per_word = t->bits_per_word;
406
407 if ((bits_per_word != 8) && (bits_per_word != 16)) {
408 dev_err(&spi->dev,
409 "message rejected : "
410 "invalid transfer bits_per_word (%d bits)\n",
411 bits_per_word);
412 goto msg_rejected;
413 }
414 /*make sure buffer length is even when working in 16 bit mode*/
415 if ((t->bits_per_word == 16) && (t->len & 1)) {
416 dev_err(&spi->dev,
417 "message rejected : "
418 "odd data length (%d) while in 16 bit mode\n",
419 t->len);
420 goto msg_rejected;
421 }
422
423 if (t->speed_hz && t->speed_hz < orion_spi->min_speed) {
424 dev_err(&spi->dev,
425 "message rejected : "
426 "device min speed (%d Hz) exceeds "
427 "required transfer speed (%d Hz)\n",
428 orion_spi->min_speed, t->speed_hz);
429 goto msg_rejected;
430 }
431 }
432
433
434 spin_lock_irqsave(&orion_spi->lock, flags);
435 list_add_tail(&m->queue, &orion_spi->msg_queue);
436 queue_work(orion_spi_wq, &orion_spi->work);
437 spin_unlock_irqrestore(&orion_spi->lock, flags);
438
439 return 0;
440msg_rejected:
441 /* Message rejected and not queued */
442 m->status = -EINVAL;
443 if (m->complete)
444 m->complete(m->context);
445 return -EINVAL;
446}
447
448static int __init orion_spi_probe(struct platform_device *pdev)
449{
450 struct spi_master *master;
451 struct orion_spi *spi;
452 struct resource *r;
453 struct orion_spi_info *spi_info;
454 unsigned long tclk_hz;
455 int status = 0;
456
457 spi_info = pdev->dev.platform_data;
458
459 master = spi_alloc_master(&pdev->dev, sizeof *spi);
460 if (master == NULL) {
461 dev_dbg(&pdev->dev, "master allocation failed\n");
462 return -ENOMEM;
463 }
464
465 if (pdev->id != -1)
466 master->bus_num = pdev->id;
467
468 /* we support only mode 0, and no options */
469 master->mode_bits = 0;
470
471 master->setup = orion_spi_setup;
472 master->transfer = orion_spi_transfer;
473 master->num_chipselect = ORION_NUM_CHIPSELECTS;
474
475 dev_set_drvdata(&pdev->dev, master);
476
477 spi = spi_master_get_devdata(master);
478 spi->master = master;
479 spi->spi_info = spi_info;
480
481 spi->clk = clk_get(&pdev->dev, NULL);
482 if (IS_ERR(spi->clk)) {
483 status = PTR_ERR(spi->clk);
484 goto out;
485 }
486
487 clk_prepare(spi->clk);
488 clk_enable(spi->clk);
489 tclk_hz = clk_get_rate(spi->clk);
490 spi->max_speed = DIV_ROUND_UP(tclk_hz, 4);
491 spi->min_speed = DIV_ROUND_UP(tclk_hz, 30);
492
493 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
494 if (r == NULL) {
495 status = -ENODEV;
496 goto out_rel_clk;
497 }
498
499 if (!request_mem_region(r->start, resource_size(r),
500 dev_name(&pdev->dev))) {
501 status = -EBUSY;
502 goto out_rel_clk;
503 }
504 spi->base = ioremap(r->start, SZ_1K);
505
506 INIT_WORK(&spi->work, orion_spi_work);
507
508 spin_lock_init(&spi->lock);
509 INIT_LIST_HEAD(&spi->msg_queue);
510
511 if (orion_spi_reset(spi) < 0)
512 goto out_rel_mem;
513
514 status = spi_register_master(master);
515 if (status < 0)
516 goto out_rel_mem;
517
518 return status;
519
520out_rel_mem:
521 release_mem_region(r->start, resource_size(r));
522out_rel_clk:
523 clk_disable_unprepare(spi->clk);
524 clk_put(spi->clk);
525out:
526 spi_master_put(master);
527 return status;
528}
529
530
531static int __exit orion_spi_remove(struct platform_device *pdev)
532{
533 struct spi_master *master;
534 struct orion_spi *spi;
535 struct resource *r;
536
537 master = dev_get_drvdata(&pdev->dev);
538 spi = spi_master_get_devdata(master);
539
540 cancel_work_sync(&spi->work);
541
542 clk_disable_unprepare(spi->clk);
543 clk_put(spi->clk);
544
545 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
546 release_mem_region(r->start, resource_size(r));
547
548 spi_unregister_master(master);
549
550 return 0;
551}
552
553MODULE_ALIAS("platform:" DRIVER_NAME);
554
555static struct platform_driver orion_spi_driver = {
556 .driver = {
557 .name = DRIVER_NAME,
558 .owner = THIS_MODULE,
559 },
560 .remove = __exit_p(orion_spi_remove),
561};
562
563static int __init orion_spi_init(void)
564{
565 orion_spi_wq = create_singlethread_workqueue(
566 orion_spi_driver.driver.name);
567 if (orion_spi_wq == NULL)
568 return -ENOMEM;
569
570 return platform_driver_probe(&orion_spi_driver, orion_spi_probe);
571}
572module_init(orion_spi_init);
573
574static void __exit orion_spi_exit(void)
575{
576 flush_workqueue(orion_spi_wq);
577 platform_driver_unregister(&orion_spi_driver);
578
579 destroy_workqueue(orion_spi_wq);
580}
581module_exit(orion_spi_exit);
582
583MODULE_DESCRIPTION("Orion SPI driver");
584MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
585MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Marvell Orion SPI controller driver
4 *
5 * Author: Shadi Ammouri <shadi@marvell.com>
6 * Copyright (C) 2007-2008 Marvell Ltd.
7 */
8
9#include <linux/interrupt.h>
10#include <linux/delay.h>
11#include <linux/platform_device.h>
12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/spi/spi.h>
15#include <linux/module.h>
16#include <linux/pm_runtime.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/of_device.h>
20#include <linux/clk.h>
21#include <linux/sizes.h>
22#include <asm/unaligned.h>
23
24#define DRIVER_NAME "orion_spi"
25
26/* Runtime PM autosuspend timeout: PM is fairly light on this driver */
27#define SPI_AUTOSUSPEND_TIMEOUT 200
28
29/* Some SoCs using this driver support up to 8 chip selects.
30 * It is up to the implementer to only use the chip selects
31 * that are available.
32 */
33#define ORION_NUM_CHIPSELECTS 8
34
35#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
36
37#define ORION_SPI_IF_CTRL_REG 0x00
38#define ORION_SPI_IF_CONFIG_REG 0x04
39#define ORION_SPI_IF_RXLSBF BIT(14)
40#define ORION_SPI_IF_TXLSBF BIT(13)
41#define ORION_SPI_DATA_OUT_REG 0x08
42#define ORION_SPI_DATA_IN_REG 0x0c
43#define ORION_SPI_INT_CAUSE_REG 0x10
44#define ORION_SPI_TIMING_PARAMS_REG 0x18
45
46/* Register for the "Direct Mode" */
47#define SPI_DIRECT_WRITE_CONFIG_REG 0x20
48
49#define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
50#define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
51#define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)
52
53#define ORION_SPI_MODE_CPOL (1 << 11)
54#define ORION_SPI_MODE_CPHA (1 << 12)
55#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
56#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
57#define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF
58#define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \
59 ORION_SPI_MODE_CPHA)
60#define ORION_SPI_CS_MASK 0x1C
61#define ORION_SPI_CS_SHIFT 2
62#define ORION_SPI_CS(cs) ((cs << ORION_SPI_CS_SHIFT) & \
63 ORION_SPI_CS_MASK)
64
65enum orion_spi_type {
66 ORION_SPI,
67 ARMADA_SPI,
68};
69
70struct orion_spi_dev {
71 enum orion_spi_type typ;
72 /*
73 * min_divisor and max_hz should be exclusive, the only we can
74 * have both is for managing the armada-370-spi case with old
75 * device tree
76 */
77 unsigned long max_hz;
78 unsigned int min_divisor;
79 unsigned int max_divisor;
80 u32 prescale_mask;
81 bool is_errata_50mhz_ac;
82};
83
84struct orion_direct_acc {
85 void __iomem *vaddr;
86 u32 size;
87};
88
89struct orion_child_options {
90 struct orion_direct_acc direct_access;
91};
92
93struct orion_spi {
94 struct spi_master *master;
95 void __iomem *base;
96 struct clk *clk;
97 struct clk *axi_clk;
98 const struct orion_spi_dev *devdata;
99 struct device *dev;
100
101 struct orion_child_options child[ORION_NUM_CHIPSELECTS];
102};
103
104#ifdef CONFIG_PM
105static int orion_spi_runtime_suspend(struct device *dev);
106static int orion_spi_runtime_resume(struct device *dev);
107#endif
108
109static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
110{
111 return orion_spi->base + reg;
112}
113
114static inline void
115orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
116{
117 void __iomem *reg_addr = spi_reg(orion_spi, reg);
118 u32 val;
119
120 val = readl(reg_addr);
121 val |= mask;
122 writel(val, reg_addr);
123}
124
125static inline void
126orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
127{
128 void __iomem *reg_addr = spi_reg(orion_spi, reg);
129 u32 val;
130
131 val = readl(reg_addr);
132 val &= ~mask;
133 writel(val, reg_addr);
134}
135
136static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
137{
138 u32 tclk_hz;
139 u32 rate;
140 u32 prescale;
141 u32 reg;
142 struct orion_spi *orion_spi;
143 const struct orion_spi_dev *devdata;
144
145 orion_spi = spi_master_get_devdata(spi->master);
146 devdata = orion_spi->devdata;
147
148 tclk_hz = clk_get_rate(orion_spi->clk);
149
150 if (devdata->typ == ARMADA_SPI) {
151 /*
152 * Given the core_clk (tclk_hz) and the target rate (speed) we
153 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
154 * [0..7]) such that
155 *
156 * core_clk / (SPR * 2 ** SPPR)
157 *
158 * is as big as possible but not bigger than speed.
159 */
160
161 /* best integer divider: */
162 unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
163 unsigned spr, sppr;
164
165 if (divider < 16) {
166 /* This is the easy case, divider is less than 16 */
167 spr = divider;
168 sppr = 0;
169
170 } else {
171 unsigned two_pow_sppr;
172 /*
173 * Find the highest bit set in divider. This and the
174 * three next bits define SPR (apart from rounding).
175 * SPPR is then the number of zero bits that must be
176 * appended:
177 */
178 sppr = fls(divider) - 4;
179
180 /*
181 * As SPR only has 4 bits, we have to round divider up
182 * to the next multiple of 2 ** sppr.
183 */
184 two_pow_sppr = 1 << sppr;
185 divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
186
187 /*
188 * recalculate sppr as rounding up divider might have
189 * increased it enough to change the position of the
190 * highest set bit. In this case the bit that now
191 * doesn't make it into SPR is 0, so there is no need to
192 * round again.
193 */
194 sppr = fls(divider) - 4;
195 spr = divider >> sppr;
196
197 /*
198 * Now do range checking. SPR is constructed to have a
199 * width of 4 bits, so this is fine for sure. So we
200 * still need to check for sppr to fit into 3 bits:
201 */
202 if (sppr > 7)
203 return -EINVAL;
204 }
205
206 prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
207 } else {
208 /*
209 * the supported rates are: 4,6,8...30
210 * round up as we look for equal or less speed
211 */
212 rate = DIV_ROUND_UP(tclk_hz, speed);
213 rate = roundup(rate, 2);
214
215 /* check if requested speed is too small */
216 if (rate > 30)
217 return -EINVAL;
218
219 if (rate < 4)
220 rate = 4;
221
222 /* Convert the rate to SPI clock divisor value. */
223 prescale = 0x10 + rate/2;
224 }
225
226 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
227 reg = ((reg & ~devdata->prescale_mask) | prescale);
228 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
229
230 return 0;
231}
232
233static void
234orion_spi_mode_set(struct spi_device *spi)
235{
236 u32 reg;
237 struct orion_spi *orion_spi;
238
239 orion_spi = spi_master_get_devdata(spi->master);
240
241 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
242 reg &= ~ORION_SPI_MODE_MASK;
243 if (spi->mode & SPI_CPOL)
244 reg |= ORION_SPI_MODE_CPOL;
245 if (spi->mode & SPI_CPHA)
246 reg |= ORION_SPI_MODE_CPHA;
247 if (spi->mode & SPI_LSB_FIRST)
248 reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
249 else
250 reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
251
252 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
253}
254
255static void
256orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
257{
258 u32 reg;
259 struct orion_spi *orion_spi;
260
261 orion_spi = spi_master_get_devdata(spi->master);
262
263 /*
264 * Erratum description: (Erratum NO. FE-9144572) The device
265 * SPI interface supports frequencies of up to 50 MHz.
266 * However, due to this erratum, when the device core clock is
267 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
268 * clock and CPOL=CPHA=1 there might occur data corruption on
269 * reads from the SPI device.
270 * Erratum Workaround:
271 * Work in one of the following configurations:
272 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
273 * Register".
274 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
275 * Register" before setting the interface.
276 */
277 reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
278 reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
279
280 if (clk_get_rate(orion_spi->clk) == 250000000 &&
281 speed == 50000000 && spi->mode & SPI_CPOL &&
282 spi->mode & SPI_CPHA)
283 reg |= ORION_SPI_TMISO_SAMPLE_2;
284 else
285 reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
286
287 writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
288}
289
290/*
291 * called only when no transfer is active on the bus
292 */
293static int
294orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
295{
296 struct orion_spi *orion_spi;
297 unsigned int speed = spi->max_speed_hz;
298 unsigned int bits_per_word = spi->bits_per_word;
299 int rc;
300
301 orion_spi = spi_master_get_devdata(spi->master);
302
303 if ((t != NULL) && t->speed_hz)
304 speed = t->speed_hz;
305
306 if ((t != NULL) && t->bits_per_word)
307 bits_per_word = t->bits_per_word;
308
309 orion_spi_mode_set(spi);
310
311 if (orion_spi->devdata->is_errata_50mhz_ac)
312 orion_spi_50mhz_ac_timing_erratum(spi, speed);
313
314 rc = orion_spi_baudrate_set(spi, speed);
315 if (rc)
316 return rc;
317
318 if (bits_per_word == 16)
319 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
320 ORION_SPI_IF_8_16_BIT_MODE);
321 else
322 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
323 ORION_SPI_IF_8_16_BIT_MODE);
324
325 return 0;
326}
327
328static void orion_spi_set_cs(struct spi_device *spi, bool enable)
329{
330 struct orion_spi *orion_spi;
331 void __iomem *ctrl_reg;
332 u32 val;
333
334 orion_spi = spi_master_get_devdata(spi->master);
335 ctrl_reg = spi_reg(orion_spi, ORION_SPI_IF_CTRL_REG);
336
337 val = readl(ctrl_reg);
338
339 /* Clear existing chip-select and assertion state */
340 val &= ~(ORION_SPI_CS_MASK | 0x1);
341
342 /*
343 * If this line is using a GPIO to control chip select, this internal
344 * .set_cs() function will still be called, so we clear any previous
345 * chip select. The CS we activate will not have any elecrical effect,
346 * as it is handled by a GPIO, but that doesn't matter. What we need
347 * is to deassert the old chip select and assert some other chip select.
348 */
349 val |= ORION_SPI_CS(spi->chip_select);
350
351 /*
352 * Chip select logic is inverted from spi_set_cs(). For lines using a
353 * GPIO to do chip select SPI_CS_HIGH is enforced and inversion happens
354 * in the GPIO library, but we don't care about that, because in those
355 * cases we are dealing with an unused native CS anyways so the polarity
356 * doesn't matter.
357 */
358 if (!enable)
359 val |= 0x1;
360
361 /*
362 * To avoid toggling unwanted chip selects update the register
363 * with a single write.
364 */
365 writel(val, ctrl_reg);
366}
367
368static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
369{
370 int i;
371
372 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
373 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
374 return 1;
375
376 udelay(1);
377 }
378
379 return -1;
380}
381
382static inline int
383orion_spi_write_read_8bit(struct spi_device *spi,
384 const u8 **tx_buf, u8 **rx_buf)
385{
386 void __iomem *tx_reg, *rx_reg, *int_reg;
387 struct orion_spi *orion_spi;
388 bool cs_single_byte;
389
390 cs_single_byte = spi->mode & SPI_CS_WORD;
391
392 orion_spi = spi_master_get_devdata(spi->master);
393
394 if (cs_single_byte)
395 orion_spi_set_cs(spi, 0);
396
397 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
398 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
399 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
400
401 /* clear the interrupt cause register */
402 writel(0x0, int_reg);
403
404 if (tx_buf && *tx_buf)
405 writel(*(*tx_buf)++, tx_reg);
406 else
407 writel(0, tx_reg);
408
409 if (orion_spi_wait_till_ready(orion_spi) < 0) {
410 if (cs_single_byte) {
411 orion_spi_set_cs(spi, 1);
412 /* Satisfy some SLIC devices requirements */
413 udelay(4);
414 }
415 dev_err(&spi->dev, "TXS timed out\n");
416 return -1;
417 }
418
419 if (rx_buf && *rx_buf)
420 *(*rx_buf)++ = readl(rx_reg);
421
422 if (cs_single_byte) {
423 orion_spi_set_cs(spi, 1);
424 /* Satisfy some SLIC devices requirements */
425 udelay(4);
426 }
427
428 return 1;
429}
430
431static inline int
432orion_spi_write_read_16bit(struct spi_device *spi,
433 const u16 **tx_buf, u16 **rx_buf)
434{
435 void __iomem *tx_reg, *rx_reg, *int_reg;
436 struct orion_spi *orion_spi;
437
438 if (spi->mode & SPI_CS_WORD) {
439 dev_err(&spi->dev, "SPI_CS_WORD is only supported for 8 bit words\n");
440 return -1;
441 }
442
443 orion_spi = spi_master_get_devdata(spi->master);
444 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
445 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
446 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
447
448 /* clear the interrupt cause register */
449 writel(0x0, int_reg);
450
451 if (tx_buf && *tx_buf)
452 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
453 else
454 writel(0, tx_reg);
455
456 if (orion_spi_wait_till_ready(orion_spi) < 0) {
457 dev_err(&spi->dev, "TXS timed out\n");
458 return -1;
459 }
460
461 if (rx_buf && *rx_buf)
462 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
463
464 return 1;
465}
466
467static unsigned int
468orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
469{
470 unsigned int count;
471 int word_len;
472 struct orion_spi *orion_spi;
473 int cs = spi->chip_select;
474 void __iomem *vaddr;
475
476 word_len = spi->bits_per_word;
477 count = xfer->len;
478
479 orion_spi = spi_master_get_devdata(spi->master);
480
481 /*
482 * Use SPI direct write mode if base address is available
483 * and SPI_CS_WORD flag is not set.
484 * Otherwise fall back to PIO mode for this transfer.
485 */
486 vaddr = orion_spi->child[cs].direct_access.vaddr;
487
488 if (vaddr && xfer->tx_buf && word_len == 8 && (spi->mode & SPI_CS_WORD) == 0) {
489 unsigned int cnt = count / 4;
490 unsigned int rem = count % 4;
491
492 /*
493 * Send the TX-data to the SPI device via the direct
494 * mapped address window
495 */
496 iowrite32_rep(vaddr, xfer->tx_buf, cnt);
497 if (rem) {
498 u32 *buf = (u32 *)xfer->tx_buf;
499
500 iowrite8_rep(vaddr, &buf[cnt], rem);
501 }
502
503 return count;
504 }
505
506 if (word_len == 8) {
507 const u8 *tx = xfer->tx_buf;
508 u8 *rx = xfer->rx_buf;
509
510 do {
511 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
512 goto out;
513 count--;
514 spi_delay_exec(&xfer->word_delay, xfer);
515 } while (count);
516 } else if (word_len == 16) {
517 const u16 *tx = xfer->tx_buf;
518 u16 *rx = xfer->rx_buf;
519
520 do {
521 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
522 goto out;
523 count -= 2;
524 spi_delay_exec(&xfer->word_delay, xfer);
525 } while (count);
526 }
527
528out:
529 return xfer->len - count;
530}
531
532static int orion_spi_transfer_one(struct spi_master *master,
533 struct spi_device *spi,
534 struct spi_transfer *t)
535{
536 int status = 0;
537
538 status = orion_spi_setup_transfer(spi, t);
539 if (status < 0)
540 return status;
541
542 if (t->len)
543 orion_spi_write_read(spi, t);
544
545 return status;
546}
547
548static int orion_spi_setup(struct spi_device *spi)
549{
550 int ret;
551#ifdef CONFIG_PM
552 struct orion_spi *orion_spi = spi_master_get_devdata(spi->master);
553 struct device *dev = orion_spi->dev;
554
555 orion_spi_runtime_resume(dev);
556#endif
557
558 ret = orion_spi_setup_transfer(spi, NULL);
559
560#ifdef CONFIG_PM
561 orion_spi_runtime_suspend(dev);
562#endif
563
564 return ret;
565}
566
567static int orion_spi_reset(struct orion_spi *orion_spi)
568{
569 /* Verify that the CS is deasserted */
570 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
571
572 /* Don't deassert CS between the direct mapped SPI transfers */
573 writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
574
575 return 0;
576}
577
578static const struct orion_spi_dev orion_spi_dev_data = {
579 .typ = ORION_SPI,
580 .min_divisor = 4,
581 .max_divisor = 30,
582 .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
583};
584
585static const struct orion_spi_dev armada_370_spi_dev_data = {
586 .typ = ARMADA_SPI,
587 .min_divisor = 4,
588 .max_divisor = 1920,
589 .max_hz = 50000000,
590 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
591};
592
593static const struct orion_spi_dev armada_xp_spi_dev_data = {
594 .typ = ARMADA_SPI,
595 .max_hz = 50000000,
596 .max_divisor = 1920,
597 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
598};
599
600static const struct orion_spi_dev armada_375_spi_dev_data = {
601 .typ = ARMADA_SPI,
602 .min_divisor = 15,
603 .max_divisor = 1920,
604 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
605};
606
607static const struct orion_spi_dev armada_380_spi_dev_data = {
608 .typ = ARMADA_SPI,
609 .max_hz = 50000000,
610 .max_divisor = 1920,
611 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
612 .is_errata_50mhz_ac = true,
613};
614
615static const struct of_device_id orion_spi_of_match_table[] = {
616 {
617 .compatible = "marvell,orion-spi",
618 .data = &orion_spi_dev_data,
619 },
620 {
621 .compatible = "marvell,armada-370-spi",
622 .data = &armada_370_spi_dev_data,
623 },
624 {
625 .compatible = "marvell,armada-375-spi",
626 .data = &armada_375_spi_dev_data,
627 },
628 {
629 .compatible = "marvell,armada-380-spi",
630 .data = &armada_380_spi_dev_data,
631 },
632 {
633 .compatible = "marvell,armada-390-spi",
634 .data = &armada_xp_spi_dev_data,
635 },
636 {
637 .compatible = "marvell,armada-xp-spi",
638 .data = &armada_xp_spi_dev_data,
639 },
640
641 {}
642};
643MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
644
645static int orion_spi_probe(struct platform_device *pdev)
646{
647 const struct orion_spi_dev *devdata;
648 struct spi_master *master;
649 struct orion_spi *spi;
650 struct resource *r;
651 unsigned long tclk_hz;
652 int status = 0;
653 struct device_node *np;
654
655 master = spi_alloc_master(&pdev->dev, sizeof(*spi));
656 if (master == NULL) {
657 dev_dbg(&pdev->dev, "master allocation failed\n");
658 return -ENOMEM;
659 }
660
661 if (pdev->id != -1)
662 master->bus_num = pdev->id;
663 if (pdev->dev.of_node) {
664 u32 cell_index;
665
666 if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
667 &cell_index))
668 master->bus_num = cell_index;
669 }
670
671 /* we support all 4 SPI modes and LSB first option */
672 master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST | SPI_CS_WORD;
673 master->set_cs = orion_spi_set_cs;
674 master->transfer_one = orion_spi_transfer_one;
675 master->num_chipselect = ORION_NUM_CHIPSELECTS;
676 master->setup = orion_spi_setup;
677 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
678 master->auto_runtime_pm = true;
679 master->use_gpio_descriptors = true;
680 master->flags = SPI_MASTER_GPIO_SS;
681
682 platform_set_drvdata(pdev, master);
683
684 spi = spi_master_get_devdata(master);
685 spi->master = master;
686 spi->dev = &pdev->dev;
687
688 devdata = device_get_match_data(&pdev->dev);
689 devdata = devdata ? devdata : &orion_spi_dev_data;
690 spi->devdata = devdata;
691
692 spi->clk = devm_clk_get(&pdev->dev, NULL);
693 if (IS_ERR(spi->clk)) {
694 status = PTR_ERR(spi->clk);
695 goto out;
696 }
697
698 status = clk_prepare_enable(spi->clk);
699 if (status)
700 goto out;
701
702 /* The following clock is only used by some SoCs */
703 spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
704 if (PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
705 status = -EPROBE_DEFER;
706 goto out_rel_clk;
707 }
708 if (!IS_ERR(spi->axi_clk))
709 clk_prepare_enable(spi->axi_clk);
710
711 tclk_hz = clk_get_rate(spi->clk);
712
713 /*
714 * With old device tree, armada-370-spi could be used with
715 * Armada XP, however for this SoC the maximum frequency is
716 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
717 * higher than 200MHz. So, in order to be able to handle both
718 * SoCs, we can take the minimum of 50MHz and tclk/4.
719 */
720 if (of_device_is_compatible(pdev->dev.of_node,
721 "marvell,armada-370-spi"))
722 master->max_speed_hz = min(devdata->max_hz,
723 DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
724 else if (devdata->min_divisor)
725 master->max_speed_hz =
726 DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
727 else
728 master->max_speed_hz = devdata->max_hz;
729 master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
730
731 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
732 spi->base = devm_ioremap_resource(&pdev->dev, r);
733 if (IS_ERR(spi->base)) {
734 status = PTR_ERR(spi->base);
735 goto out_rel_axi_clk;
736 }
737
738 for_each_available_child_of_node(pdev->dev.of_node, np) {
739 struct orion_direct_acc *dir_acc;
740 u32 cs;
741
742 /* Get chip-select number from the "reg" property */
743 status = of_property_read_u32(np, "reg", &cs);
744 if (status) {
745 dev_err(&pdev->dev,
746 "%pOF has no valid 'reg' property (%d)\n",
747 np, status);
748 continue;
749 }
750
751 /*
752 * Check if an address is configured for this SPI device. If
753 * not, the MBus mapping via the 'ranges' property in the 'soc'
754 * node is not configured and this device should not use the
755 * direct mode. In this case, just continue with the next
756 * device.
757 */
758 status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
759 if (status)
760 continue;
761
762 /*
763 * Only map one page for direct access. This is enough for the
764 * simple TX transfer which only writes to the first word.
765 * This needs to get extended for the direct SPI NOR / SPI NAND
766 * support, once this gets implemented.
767 */
768 dir_acc = &spi->child[cs].direct_access;
769 dir_acc->vaddr = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
770 if (!dir_acc->vaddr) {
771 status = -ENOMEM;
772 of_node_put(np);
773 goto out_rel_axi_clk;
774 }
775 dir_acc->size = PAGE_SIZE;
776
777 dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
778 }
779
780 pm_runtime_set_active(&pdev->dev);
781 pm_runtime_use_autosuspend(&pdev->dev);
782 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
783 pm_runtime_enable(&pdev->dev);
784
785 status = orion_spi_reset(spi);
786 if (status < 0)
787 goto out_rel_pm;
788
789 master->dev.of_node = pdev->dev.of_node;
790 status = spi_register_master(master);
791 if (status < 0)
792 goto out_rel_pm;
793
794 return status;
795
796out_rel_pm:
797 pm_runtime_disable(&pdev->dev);
798out_rel_axi_clk:
799 clk_disable_unprepare(spi->axi_clk);
800out_rel_clk:
801 clk_disable_unprepare(spi->clk);
802out:
803 spi_master_put(master);
804 return status;
805}
806
807
808static int orion_spi_remove(struct platform_device *pdev)
809{
810 struct spi_master *master = platform_get_drvdata(pdev);
811 struct orion_spi *spi = spi_master_get_devdata(master);
812
813 pm_runtime_get_sync(&pdev->dev);
814 clk_disable_unprepare(spi->axi_clk);
815 clk_disable_unprepare(spi->clk);
816
817 spi_unregister_master(master);
818 pm_runtime_disable(&pdev->dev);
819
820 return 0;
821}
822
823MODULE_ALIAS("platform:" DRIVER_NAME);
824
825#ifdef CONFIG_PM
826static int orion_spi_runtime_suspend(struct device *dev)
827{
828 struct spi_master *master = dev_get_drvdata(dev);
829 struct orion_spi *spi = spi_master_get_devdata(master);
830
831 clk_disable_unprepare(spi->axi_clk);
832 clk_disable_unprepare(spi->clk);
833 return 0;
834}
835
836static int orion_spi_runtime_resume(struct device *dev)
837{
838 struct spi_master *master = dev_get_drvdata(dev);
839 struct orion_spi *spi = spi_master_get_devdata(master);
840
841 if (!IS_ERR(spi->axi_clk))
842 clk_prepare_enable(spi->axi_clk);
843 return clk_prepare_enable(spi->clk);
844}
845#endif
846
847static const struct dev_pm_ops orion_spi_pm_ops = {
848 SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
849 orion_spi_runtime_resume,
850 NULL)
851};
852
853static struct platform_driver orion_spi_driver = {
854 .driver = {
855 .name = DRIVER_NAME,
856 .pm = &orion_spi_pm_ops,
857 .of_match_table = of_match_ptr(orion_spi_of_match_table),
858 },
859 .probe = orion_spi_probe,
860 .remove = orion_spi_remove,
861};
862
863module_platform_driver(orion_spi_driver);
864
865MODULE_DESCRIPTION("Orion SPI driver");
866MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
867MODULE_LICENSE("GPL");