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>
17 #include <linux/spi/spi.h>
18 #include <linux/module.h>
19 #include <linux/pm_runtime.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
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 | \
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) & \
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
75 unsigned int min_divisor
;
76 unsigned int max_divisor
;
78 bool is_errata_50mhz_ac
;
82 struct spi_master
*master
;
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
;
94 orion_spi_setbits(struct orion_spi
*orion_spi
, u32 reg
, u32 mask
)
96 void __iomem
*reg_addr
= spi_reg(orion_spi
, reg
);
99 val
= readl(reg_addr
);
101 writel(val
, reg_addr
);
105 orion_spi_clrbits(struct orion_spi
*orion_spi
, u32 reg
, u32 mask
)
107 void __iomem
*reg_addr
= spi_reg(orion_spi
, reg
);
110 val
= readl(reg_addr
);
112 writel(val
, reg_addr
);
115 static int orion_spi_baudrate_set(struct spi_device
*spi
, unsigned int speed
)
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
;
137 /* Iterate over the valid range looking for best fit */
138 for (sppr
= 0; sppr
< 8; sppr
++) {
141 spr
= tclk_hz
/ sppr2
;
142 spr
= DIV_ROUND_UP(spr
, speed
);
143 if ((spr
== 0) || (spr
> 15))
146 clk
= tclk_hz
/ (spr
* sppr2
);
149 if (err
< best_err
) {
156 if ((best_sppr
== 0) && (best_spr
== 0))
159 prescale
= ((best_sppr
& 0x6) << 5) |
160 ((best_sppr
& 0x1) << 4) | best_spr
;
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 */
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
));
188 orion_spi_mode_set(struct spi_device
*spi
)
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
));
205 orion_spi_50mhz_ac_timing_erratum(struct spi_device
*spi
, unsigned int speed
)
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
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
;
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
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
;
250 orion_spi
= spi_master_get_devdata(spi
->master
);
252 if ((t
!= NULL
) && 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
);
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
);
271 orion_spi_clrbits(orion_spi
, ORION_SPI_IF_CONFIG_REG
,
272 ORION_SPI_IF_8_16_BIT_MODE
);
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 */
289 orion_spi_setbits(orion_spi
, ORION_SPI_IF_CTRL_REG
, 0x1);
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
)
298 for (i
= 0; i
< ORION_SPI_WAIT_RDY_MAX_LOOP
; i
++) {
299 if (readl(spi_reg(orion_spi
, ORION_SPI_INT_CAUSE_REG
)))
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
);
328 if (orion_spi_wait_till_ready(orion_spi
) < 0) {
329 dev_err(&spi
->dev
, "TXS timed out\n");
333 if (rx_buf
&& *rx_buf
)
334 *(*rx_buf
)++ = readl(rx_reg
);
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
);
359 if (orion_spi_wait_till_ready(orion_spi
) < 0) {
360 dev_err(&spi
->dev
, "TXS timed out\n");
364 if (rx_buf
&& *rx_buf
)
365 put_unaligned(__le16_to_cpu(readl(rx_reg
)), (*rx_buf
)++);
371 orion_spi_write_read(struct spi_device
*spi
, struct spi_transfer
*xfer
)
376 word_len
= spi
->bits_per_word
;
380 const u8
*tx
= xfer
->tx_buf
;
381 u8
*rx
= xfer
->rx_buf
;
384 if (orion_spi_write_read_8bit(spi
, &tx
, &rx
) < 0)
388 } else if (word_len
== 16) {
389 const u16
*tx
= xfer
->tx_buf
;
390 u16
*rx
= xfer
->rx_buf
;
393 if (orion_spi_write_read_16bit(spi
, &tx
, &rx
) < 0)
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
)
409 status
= orion_spi_setup_transfer(spi
, t
);
414 orion_spi_write_read(spi
, t
);
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);
431 static const struct orion_spi_dev orion_spi_dev_data
= {
435 .prescale_mask
= ORION_SPI_CLK_PRESCALE_MASK
,
438 static const struct orion_spi_dev armada_370_spi_dev_data
= {
443 .prescale_mask
= ARMADA_SPI_CLK_PRESCALE_MASK
,
446 static const struct orion_spi_dev armada_xp_spi_dev_data
= {
450 .prescale_mask
= ARMADA_SPI_CLK_PRESCALE_MASK
,
453 static const struct orion_spi_dev armada_375_spi_dev_data
= {
457 .prescale_mask
= ARMADA_SPI_CLK_PRESCALE_MASK
,
460 static const struct orion_spi_dev armada_380_spi_dev_data
= {
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
;
505 unsigned long tclk_hz
;
508 master
= spi_alloc_master(&pdev
->dev
, sizeof(*spi
));
509 if (master
== NULL
) {
510 dev_dbg(&pdev
->dev
, "master allocation failed\n");
515 master
->bus_num
= pdev
->id
;
516 if (pdev
->dev
.of_node
) {
519 if (!of_property_read_u32(pdev
->dev
.of_node
, "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
);
548 status
= clk_prepare_enable(spi
->clk
);
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
);
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
);
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
);
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
);
599 pm_runtime_disable(&pdev
->dev
);
601 clk_disable_unprepare(spi
->clk
);
603 spi_master_put(master
);
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
);
622 MODULE_ALIAS("platform:" DRIVER_NAME
);
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
);
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
);
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
,
649 static struct platform_driver orion_spi_driver
= {
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");