Linux 4.2.1
[linux/fpc-iii.git] / drivers / spi / spi-orion.c
bloba87cfd4ba17b38f47a8e6c823c335c308c482dc8
1 /*
2 * Marvell Orion SPI controller driver
4 * Author: Shadi Ammouri <shadi@marvell.com>
5 * Copyright (C) 2007-2008 Marvell Ltd.
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.
12 #include <linux/interrupt.h>
13 #include <linux/delay.h>
14 #include <linux/platform_device.h>
15 #include <linux/err.h>
16 #include <linux/io.h>
17 #include <linux/spi/spi.h>
18 #include <linux/module.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/clk.h>
23 #include <linux/sizes.h>
24 #include <asm/unaligned.h>
26 #define DRIVER_NAME "orion_spi"
28 /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
29 #define SPI_AUTOSUSPEND_TIMEOUT 200
31 /* Some SoCs using this driver support up to 8 chip selects.
32 * It is up to the implementer to only use the chip selects
33 * that are available.
35 #define ORION_NUM_CHIPSELECTS 8
37 #define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
39 #define ORION_SPI_IF_CTRL_REG 0x00
40 #define ORION_SPI_IF_CONFIG_REG 0x04
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
46 #define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
47 #define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
48 #define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)
50 #define ORION_SPI_MODE_CPOL (1 << 11)
51 #define ORION_SPI_MODE_CPHA (1 << 12)
52 #define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
53 #define ORION_SPI_CLK_PRESCALE_MASK 0x1F
54 #define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF
55 #define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \
56 ORION_SPI_MODE_CPHA)
57 #define ORION_SPI_CS_MASK 0x1C
58 #define ORION_SPI_CS_SHIFT 2
59 #define ORION_SPI_CS(cs) ((cs << ORION_SPI_CS_SHIFT) & \
60 ORION_SPI_CS_MASK)
62 enum orion_spi_type {
63 ORION_SPI,
64 ARMADA_SPI,
67 struct orion_spi_dev {
68 enum orion_spi_type typ;
70 * min_divisor and max_hz should be exclusive, the only we can
71 * have both is for managing the armada-370-spi case with old
72 * device tree
74 unsigned long max_hz;
75 unsigned int min_divisor;
76 unsigned int max_divisor;
77 u32 prescale_mask;
78 bool is_errata_50mhz_ac;
81 struct orion_spi {
82 struct spi_master *master;
83 void __iomem *base;
84 struct clk *clk;
85 const struct orion_spi_dev *devdata;
88 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
90 return orion_spi->base + reg;
93 static inline void
94 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
96 void __iomem *reg_addr = spi_reg(orion_spi, reg);
97 u32 val;
99 val = readl(reg_addr);
100 val |= mask;
101 writel(val, reg_addr);
104 static inline void
105 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
107 void __iomem *reg_addr = spi_reg(orion_spi, reg);
108 u32 val;
110 val = readl(reg_addr);
111 val &= ~mask;
112 writel(val, reg_addr);
115 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
117 u32 tclk_hz;
118 u32 rate;
119 u32 prescale;
120 u32 reg;
121 struct orion_spi *orion_spi;
122 const struct orion_spi_dev *devdata;
124 orion_spi = spi_master_get_devdata(spi->master);
125 devdata = orion_spi->devdata;
127 tclk_hz = clk_get_rate(orion_spi->clk);
129 if (devdata->typ == ARMADA_SPI) {
130 unsigned int clk, spr, sppr, sppr2, err;
131 unsigned int best_spr, best_sppr, best_err;
133 best_err = speed;
134 best_spr = 0;
135 best_sppr = 0;
137 /* Iterate over the valid range looking for best fit */
138 for (sppr = 0; sppr < 8; sppr++) {
139 sppr2 = 0x1 << sppr;
141 spr = tclk_hz / sppr2;
142 spr = DIV_ROUND_UP(spr, speed);
143 if ((spr == 0) || (spr > 15))
144 continue;
146 clk = tclk_hz / (spr * sppr2);
147 err = speed - clk;
149 if (err < best_err) {
150 best_spr = spr;
151 best_sppr = sppr;
152 best_err = err;
156 if ((best_sppr == 0) && (best_spr == 0))
157 return -EINVAL;
159 prescale = ((best_sppr & 0x6) << 5) |
160 ((best_sppr & 0x1) << 4) | best_spr;
161 } else {
163 * the supported rates are: 4,6,8...30
164 * round up as we look for equal or less speed
166 rate = DIV_ROUND_UP(tclk_hz, speed);
167 rate = roundup(rate, 2);
169 /* check if requested speed is too small */
170 if (rate > 30)
171 return -EINVAL;
173 if (rate < 4)
174 rate = 4;
176 /* Convert the rate to SPI clock divisor value. */
177 prescale = 0x10 + rate/2;
180 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
181 reg = ((reg & ~devdata->prescale_mask) | prescale);
182 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
184 return 0;
187 static void
188 orion_spi_mode_set(struct spi_device *spi)
190 u32 reg;
191 struct orion_spi *orion_spi;
193 orion_spi = spi_master_get_devdata(spi->master);
195 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
196 reg &= ~ORION_SPI_MODE_MASK;
197 if (spi->mode & SPI_CPOL)
198 reg |= ORION_SPI_MODE_CPOL;
199 if (spi->mode & SPI_CPHA)
200 reg |= ORION_SPI_MODE_CPHA;
201 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
204 static void
205 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
207 u32 reg;
208 struct orion_spi *orion_spi;
210 orion_spi = spi_master_get_devdata(spi->master);
213 * Erratum description: (Erratum NO. FE-9144572) The device
214 * SPI interface supports frequencies of up to 50 MHz.
215 * However, due to this erratum, when the device core clock is
216 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
217 * clock and CPOL=CPHA=1 there might occur data corruption on
218 * reads from the SPI device.
219 * Erratum Workaround:
220 * Work in one of the following configurations:
221 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
222 * Register".
223 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
224 * Register" before setting the interface.
226 reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
227 reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
229 if (clk_get_rate(orion_spi->clk) == 250000000 &&
230 speed == 50000000 && spi->mode & SPI_CPOL &&
231 spi->mode & SPI_CPHA)
232 reg |= ORION_SPI_TMISO_SAMPLE_2;
233 else
234 reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
236 writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
240 * called only when no transfer is active on the bus
242 static int
243 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
245 struct orion_spi *orion_spi;
246 unsigned int speed = spi->max_speed_hz;
247 unsigned int bits_per_word = spi->bits_per_word;
248 int rc;
250 orion_spi = spi_master_get_devdata(spi->master);
252 if ((t != NULL) && t->speed_hz)
253 speed = t->speed_hz;
255 if ((t != NULL) && t->bits_per_word)
256 bits_per_word = t->bits_per_word;
258 orion_spi_mode_set(spi);
260 if (orion_spi->devdata->is_errata_50mhz_ac)
261 orion_spi_50mhz_ac_timing_erratum(spi, speed);
263 rc = orion_spi_baudrate_set(spi, speed);
264 if (rc)
265 return rc;
267 if (bits_per_word == 16)
268 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
269 ORION_SPI_IF_8_16_BIT_MODE);
270 else
271 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
272 ORION_SPI_IF_8_16_BIT_MODE);
274 return 0;
277 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
279 struct orion_spi *orion_spi;
281 orion_spi = spi_master_get_devdata(spi->master);
283 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
284 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
285 ORION_SPI_CS(spi->chip_select));
287 /* Chip select logic is inverted from spi_set_cs */
288 if (!enable)
289 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
290 else
291 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
294 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
296 int i;
298 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
299 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
300 return 1;
302 udelay(1);
305 return -1;
308 static inline int
309 orion_spi_write_read_8bit(struct spi_device *spi,
310 const u8 **tx_buf, u8 **rx_buf)
312 void __iomem *tx_reg, *rx_reg, *int_reg;
313 struct orion_spi *orion_spi;
315 orion_spi = spi_master_get_devdata(spi->master);
316 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
317 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
318 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
320 /* clear the interrupt cause register */
321 writel(0x0, int_reg);
323 if (tx_buf && *tx_buf)
324 writel(*(*tx_buf)++, tx_reg);
325 else
326 writel(0, tx_reg);
328 if (orion_spi_wait_till_ready(orion_spi) < 0) {
329 dev_err(&spi->dev, "TXS timed out\n");
330 return -1;
333 if (rx_buf && *rx_buf)
334 *(*rx_buf)++ = readl(rx_reg);
336 return 1;
339 static inline int
340 orion_spi_write_read_16bit(struct spi_device *spi,
341 const u16 **tx_buf, u16 **rx_buf)
343 void __iomem *tx_reg, *rx_reg, *int_reg;
344 struct orion_spi *orion_spi;
346 orion_spi = spi_master_get_devdata(spi->master);
347 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
348 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
349 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
351 /* clear the interrupt cause register */
352 writel(0x0, int_reg);
354 if (tx_buf && *tx_buf)
355 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
356 else
357 writel(0, tx_reg);
359 if (orion_spi_wait_till_ready(orion_spi) < 0) {
360 dev_err(&spi->dev, "TXS timed out\n");
361 return -1;
364 if (rx_buf && *rx_buf)
365 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
367 return 1;
370 static unsigned int
371 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
373 unsigned int count;
374 int word_len;
376 word_len = spi->bits_per_word;
377 count = xfer->len;
379 if (word_len == 8) {
380 const u8 *tx = xfer->tx_buf;
381 u8 *rx = xfer->rx_buf;
383 do {
384 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
385 goto out;
386 count--;
387 } while (count);
388 } else if (word_len == 16) {
389 const u16 *tx = xfer->tx_buf;
390 u16 *rx = xfer->rx_buf;
392 do {
393 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
394 goto out;
395 count -= 2;
396 } while (count);
399 out:
400 return xfer->len - count;
403 static int orion_spi_transfer_one(struct spi_master *master,
404 struct spi_device *spi,
405 struct spi_transfer *t)
407 int status = 0;
409 status = orion_spi_setup_transfer(spi, t);
410 if (status < 0)
411 return status;
413 if (t->len)
414 orion_spi_write_read(spi, t);
416 return status;
419 static int orion_spi_setup(struct spi_device *spi)
421 return orion_spi_setup_transfer(spi, NULL);
424 static int orion_spi_reset(struct orion_spi *orion_spi)
426 /* Verify that the CS is deasserted */
427 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
428 return 0;
431 static const struct orion_spi_dev orion_spi_dev_data = {
432 .typ = ORION_SPI,
433 .min_divisor = 4,
434 .max_divisor = 30,
435 .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
438 static const struct orion_spi_dev armada_370_spi_dev_data = {
439 .typ = ARMADA_SPI,
440 .min_divisor = 4,
441 .max_divisor = 1920,
442 .max_hz = 50000000,
443 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
446 static const struct orion_spi_dev armada_xp_spi_dev_data = {
447 .typ = ARMADA_SPI,
448 .max_hz = 50000000,
449 .max_divisor = 1920,
450 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
453 static const struct orion_spi_dev armada_375_spi_dev_data = {
454 .typ = ARMADA_SPI,
455 .min_divisor = 15,
456 .max_divisor = 1920,
457 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
460 static const struct orion_spi_dev armada_380_spi_dev_data = {
461 .typ = ARMADA_SPI,
462 .max_hz = 50000000,
463 .max_divisor = 1920,
464 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
465 .is_errata_50mhz_ac = true,
468 static const struct of_device_id orion_spi_of_match_table[] = {
470 .compatible = "marvell,orion-spi",
471 .data = &orion_spi_dev_data,
474 .compatible = "marvell,armada-370-spi",
475 .data = &armada_370_spi_dev_data,
478 .compatible = "marvell,armada-375-spi",
479 .data = &armada_375_spi_dev_data,
482 .compatible = "marvell,armada-380-spi",
483 .data = &armada_380_spi_dev_data,
486 .compatible = "marvell,armada-390-spi",
487 .data = &armada_xp_spi_dev_data,
490 .compatible = "marvell,armada-xp-spi",
491 .data = &armada_xp_spi_dev_data,
496 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
498 static int orion_spi_probe(struct platform_device *pdev)
500 const struct of_device_id *of_id;
501 const struct orion_spi_dev *devdata;
502 struct spi_master *master;
503 struct orion_spi *spi;
504 struct resource *r;
505 unsigned long tclk_hz;
506 int status = 0;
508 master = spi_alloc_master(&pdev->dev, sizeof(*spi));
509 if (master == NULL) {
510 dev_dbg(&pdev->dev, "master allocation failed\n");
511 return -ENOMEM;
514 if (pdev->id != -1)
515 master->bus_num = pdev->id;
516 if (pdev->dev.of_node) {
517 u32 cell_index;
519 if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
520 &cell_index))
521 master->bus_num = cell_index;
524 /* we support only mode 0, and no options */
525 master->mode_bits = SPI_CPHA | SPI_CPOL;
526 master->set_cs = orion_spi_set_cs;
527 master->transfer_one = orion_spi_transfer_one;
528 master->num_chipselect = ORION_NUM_CHIPSELECTS;
529 master->setup = orion_spi_setup;
530 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
531 master->auto_runtime_pm = true;
533 platform_set_drvdata(pdev, master);
535 spi = spi_master_get_devdata(master);
536 spi->master = master;
538 of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
539 devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
540 spi->devdata = devdata;
542 spi->clk = devm_clk_get(&pdev->dev, NULL);
543 if (IS_ERR(spi->clk)) {
544 status = PTR_ERR(spi->clk);
545 goto out;
548 status = clk_prepare_enable(spi->clk);
549 if (status)
550 goto out;
552 tclk_hz = clk_get_rate(spi->clk);
555 * With old device tree, armada-370-spi could be used with
556 * Armada XP, however for this SoC the maximum frequency is
557 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
558 * higher than 200MHz. So, in order to be able to handle both
559 * SoCs, we can take the minimum of 50MHz and tclk/4.
561 if (of_device_is_compatible(pdev->dev.of_node,
562 "marvell,armada-370-spi"))
563 master->max_speed_hz = min(devdata->max_hz,
564 DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
565 else if (devdata->min_divisor)
566 master->max_speed_hz =
567 DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
568 else
569 master->max_speed_hz = devdata->max_hz;
570 master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
572 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
573 spi->base = devm_ioremap_resource(&pdev->dev, r);
574 if (IS_ERR(spi->base)) {
575 status = PTR_ERR(spi->base);
576 goto out_rel_clk;
579 pm_runtime_set_active(&pdev->dev);
580 pm_runtime_use_autosuspend(&pdev->dev);
581 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
582 pm_runtime_enable(&pdev->dev);
584 status = orion_spi_reset(spi);
585 if (status < 0)
586 goto out_rel_pm;
588 pm_runtime_mark_last_busy(&pdev->dev);
589 pm_runtime_put_autosuspend(&pdev->dev);
591 master->dev.of_node = pdev->dev.of_node;
592 status = spi_register_master(master);
593 if (status < 0)
594 goto out_rel_pm;
596 return status;
598 out_rel_pm:
599 pm_runtime_disable(&pdev->dev);
600 out_rel_clk:
601 clk_disable_unprepare(spi->clk);
602 out:
603 spi_master_put(master);
604 return status;
608 static int orion_spi_remove(struct platform_device *pdev)
610 struct spi_master *master = platform_get_drvdata(pdev);
611 struct orion_spi *spi = spi_master_get_devdata(master);
613 pm_runtime_get_sync(&pdev->dev);
614 clk_disable_unprepare(spi->clk);
616 spi_unregister_master(master);
617 pm_runtime_disable(&pdev->dev);
619 return 0;
622 MODULE_ALIAS("platform:" DRIVER_NAME);
624 #ifdef CONFIG_PM
625 static int orion_spi_runtime_suspend(struct device *dev)
627 struct spi_master *master = dev_get_drvdata(dev);
628 struct orion_spi *spi = spi_master_get_devdata(master);
630 clk_disable_unprepare(spi->clk);
631 return 0;
634 static int orion_spi_runtime_resume(struct device *dev)
636 struct spi_master *master = dev_get_drvdata(dev);
637 struct orion_spi *spi = spi_master_get_devdata(master);
639 return clk_prepare_enable(spi->clk);
641 #endif
643 static const struct dev_pm_ops orion_spi_pm_ops = {
644 SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
645 orion_spi_runtime_resume,
646 NULL)
649 static struct platform_driver orion_spi_driver = {
650 .driver = {
651 .name = DRIVER_NAME,
652 .pm = &orion_spi_pm_ops,
653 .of_match_table = of_match_ptr(orion_spi_of_match_table),
655 .probe = orion_spi_probe,
656 .remove = orion_spi_remove,
659 module_platform_driver(orion_spi_driver);
661 MODULE_DESCRIPTION("Orion SPI driver");
662 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
663 MODULE_LICENSE("GPL");