1 // SPDX-License-Identifier: GPL-2.0-only
3 * SPI driver for Nvidia's Tegra20 Serial Flash Controller.
5 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
7 * Author: Laxman Dewangan <ldewangan@nvidia.com>
10 #include <linux/clk.h>
11 #include <linux/completion.h>
12 #include <linux/delay.h>
13 #include <linux/err.h>
14 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/kthread.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
22 #include <linux/of_device.h>
23 #include <linux/reset.h>
24 #include <linux/spi/spi.h>
26 #define SPI_COMMAND 0x000
27 #define SPI_GO BIT(30)
28 #define SPI_M_S BIT(28)
29 #define SPI_ACTIVE_SCLK_MASK (0x3 << 26)
30 #define SPI_ACTIVE_SCLK_DRIVE_LOW (0 << 26)
31 #define SPI_ACTIVE_SCLK_DRIVE_HIGH (1 << 26)
32 #define SPI_ACTIVE_SCLK_PULL_LOW (2 << 26)
33 #define SPI_ACTIVE_SCLK_PULL_HIGH (3 << 26)
35 #define SPI_CK_SDA_FALLING (1 << 21)
36 #define SPI_CK_SDA_RISING (0 << 21)
37 #define SPI_CK_SDA_MASK (1 << 21)
38 #define SPI_ACTIVE_SDA (0x3 << 18)
39 #define SPI_ACTIVE_SDA_DRIVE_LOW (0 << 18)
40 #define SPI_ACTIVE_SDA_DRIVE_HIGH (1 << 18)
41 #define SPI_ACTIVE_SDA_PULL_LOW (2 << 18)
42 #define SPI_ACTIVE_SDA_PULL_HIGH (3 << 18)
44 #define SPI_CS_POL_INVERT BIT(16)
45 #define SPI_TX_EN BIT(15)
46 #define SPI_RX_EN BIT(14)
47 #define SPI_CS_VAL_HIGH BIT(13)
48 #define SPI_CS_VAL_LOW 0x0
49 #define SPI_CS_SW BIT(12)
51 #define SPI_CS_DELAY_MASK (7 << 9)
52 #define SPI_CS3_EN BIT(8)
53 #define SPI_CS2_EN BIT(7)
54 #define SPI_CS1_EN BIT(6)
55 #define SPI_CS0_EN BIT(5)
57 #define SPI_CS_MASK (SPI_CS3_EN | SPI_CS2_EN | \
58 SPI_CS1_EN | SPI_CS0_EN)
59 #define SPI_BIT_LENGTH(x) (((x) & 0x1f) << 0)
61 #define SPI_MODES (SPI_ACTIVE_SCLK_MASK | SPI_CK_SDA_MASK)
63 #define SPI_STATUS 0x004
64 #define SPI_BSY BIT(31)
65 #define SPI_RDY BIT(30)
66 #define SPI_TXF_FLUSH BIT(29)
67 #define SPI_RXF_FLUSH BIT(28)
68 #define SPI_RX_UNF BIT(27)
69 #define SPI_TX_OVF BIT(26)
70 #define SPI_RXF_EMPTY BIT(25)
71 #define SPI_RXF_FULL BIT(24)
72 #define SPI_TXF_EMPTY BIT(23)
73 #define SPI_TXF_FULL BIT(22)
74 #define SPI_BLK_CNT(count) (((count) & 0xffff) + 1)
76 #define SPI_FIFO_ERROR (SPI_RX_UNF | SPI_TX_OVF)
77 #define SPI_FIFO_EMPTY (SPI_TX_EMPTY | SPI_RX_EMPTY)
79 #define SPI_RX_CMP 0x8
80 #define SPI_DMA_CTL 0x0C
81 #define SPI_DMA_EN BIT(31)
82 #define SPI_IE_RXC BIT(27)
83 #define SPI_IE_TXC BIT(26)
84 #define SPI_PACKED BIT(20)
85 #define SPI_RX_TRIG_MASK (0x3 << 18)
86 #define SPI_RX_TRIG_1W (0x0 << 18)
87 #define SPI_RX_TRIG_4W (0x1 << 18)
88 #define SPI_TX_TRIG_MASK (0x3 << 16)
89 #define SPI_TX_TRIG_1W (0x0 << 16)
90 #define SPI_TX_TRIG_4W (0x1 << 16)
91 #define SPI_DMA_BLK_COUNT(count) (((count) - 1) & 0xFFFF)
93 #define SPI_TX_FIFO 0x10
94 #define SPI_RX_FIFO 0x20
96 #define DATA_DIR_TX (1 << 0)
97 #define DATA_DIR_RX (1 << 1)
99 #define MAX_CHIP_SELECT 4
100 #define SPI_FIFO_DEPTH 4
101 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
103 struct tegra_sflash_data
{
105 struct spi_master
*master
;
109 struct reset_control
*rst
;
114 struct spi_device
*cur_spi
;
117 unsigned bytes_per_word
;
118 unsigned cur_direction
;
119 unsigned curr_xfer_words
;
132 struct completion xfer_completion
;
133 struct spi_transfer
*curr_xfer
;
136 static int tegra_sflash_runtime_suspend(struct device
*dev
);
137 static int tegra_sflash_runtime_resume(struct device
*dev
);
139 static inline u32
tegra_sflash_readl(struct tegra_sflash_data
*tsd
,
142 return readl(tsd
->base
+ reg
);
145 static inline void tegra_sflash_writel(struct tegra_sflash_data
*tsd
,
146 u32 val
, unsigned long reg
)
148 writel(val
, tsd
->base
+ reg
);
151 static void tegra_sflash_clear_status(struct tegra_sflash_data
*tsd
)
153 /* Write 1 to clear status register */
154 tegra_sflash_writel(tsd
, SPI_RDY
| SPI_FIFO_ERROR
, SPI_STATUS
);
157 static unsigned tegra_sflash_calculate_curr_xfer_param(
158 struct spi_device
*spi
, struct tegra_sflash_data
*tsd
,
159 struct spi_transfer
*t
)
161 unsigned remain_len
= t
->len
- tsd
->cur_pos
;
164 tsd
->bytes_per_word
= DIV_ROUND_UP(t
->bits_per_word
, 8);
165 max_word
= remain_len
/ tsd
->bytes_per_word
;
166 if (max_word
> SPI_FIFO_DEPTH
)
167 max_word
= SPI_FIFO_DEPTH
;
168 tsd
->curr_xfer_words
= max_word
;
172 static unsigned tegra_sflash_fill_tx_fifo_from_client_txbuf(
173 struct tegra_sflash_data
*tsd
, struct spi_transfer
*t
)
177 unsigned max_n_32bit
= tsd
->curr_xfer_words
;
178 u8
*tx_buf
= (u8
*)t
->tx_buf
+ tsd
->cur_tx_pos
;
180 if (max_n_32bit
> SPI_FIFO_DEPTH
)
181 max_n_32bit
= SPI_FIFO_DEPTH
;
182 nbytes
= max_n_32bit
* tsd
->bytes_per_word
;
184 status
= tegra_sflash_readl(tsd
, SPI_STATUS
);
185 while (!(status
& SPI_TXF_FULL
)) {
189 for (i
= 0; nbytes
&& (i
< tsd
->bytes_per_word
);
191 x
|= (u32
)(*tx_buf
++) << (i
* 8);
192 tegra_sflash_writel(tsd
, x
, SPI_TX_FIFO
);
196 status
= tegra_sflash_readl(tsd
, SPI_STATUS
);
198 tsd
->cur_tx_pos
+= max_n_32bit
* tsd
->bytes_per_word
;
202 static int tegra_sflash_read_rx_fifo_to_client_rxbuf(
203 struct tegra_sflash_data
*tsd
, struct spi_transfer
*t
)
206 unsigned int read_words
= 0;
207 u8
*rx_buf
= (u8
*)t
->rx_buf
+ tsd
->cur_rx_pos
;
209 status
= tegra_sflash_readl(tsd
, SPI_STATUS
);
210 while (!(status
& SPI_RXF_EMPTY
)) {
212 u32 x
= tegra_sflash_readl(tsd
, SPI_RX_FIFO
);
214 for (i
= 0; (i
< tsd
->bytes_per_word
); i
++)
215 *rx_buf
++ = (x
>> (i
*8)) & 0xFF;
217 status
= tegra_sflash_readl(tsd
, SPI_STATUS
);
219 tsd
->cur_rx_pos
+= read_words
* tsd
->bytes_per_word
;
223 static int tegra_sflash_start_cpu_based_transfer(
224 struct tegra_sflash_data
*tsd
, struct spi_transfer
*t
)
229 if (tsd
->cur_direction
& DATA_DIR_TX
)
232 if (tsd
->cur_direction
& DATA_DIR_RX
)
235 tegra_sflash_writel(tsd
, val
, SPI_DMA_CTL
);
236 tsd
->dma_control_reg
= val
;
238 if (tsd
->cur_direction
& DATA_DIR_TX
)
239 cur_words
= tegra_sflash_fill_tx_fifo_from_client_txbuf(tsd
, t
);
241 cur_words
= tsd
->curr_xfer_words
;
242 val
|= SPI_DMA_BLK_COUNT(cur_words
);
243 tegra_sflash_writel(tsd
, val
, SPI_DMA_CTL
);
244 tsd
->dma_control_reg
= val
;
246 tegra_sflash_writel(tsd
, val
, SPI_DMA_CTL
);
250 static int tegra_sflash_start_transfer_one(struct spi_device
*spi
,
251 struct spi_transfer
*t
, bool is_first_of_msg
,
254 struct tegra_sflash_data
*tsd
= spi_master_get_devdata(spi
->master
);
259 if (speed
!= tsd
->cur_speed
) {
260 clk_set_rate(tsd
->clk
, speed
);
261 tsd
->cur_speed
= speed
;
269 tegra_sflash_calculate_curr_xfer_param(spi
, tsd
, t
);
270 if (is_first_of_msg
) {
271 command
= tsd
->def_command_reg
;
272 command
|= SPI_BIT_LENGTH(t
->bits_per_word
- 1);
273 command
|= SPI_CS_VAL_HIGH
;
275 command
&= ~SPI_MODES
;
276 if (spi
->mode
& SPI_CPHA
)
277 command
|= SPI_CK_SDA_FALLING
;
279 if (spi
->mode
& SPI_CPOL
)
280 command
|= SPI_ACTIVE_SCLK_DRIVE_HIGH
;
282 command
|= SPI_ACTIVE_SCLK_DRIVE_LOW
;
283 command
|= SPI_CS0_EN
<< spi
->chip_select
;
285 command
= tsd
->command_reg
;
286 command
&= ~SPI_BIT_LENGTH(~0);
287 command
|= SPI_BIT_LENGTH(t
->bits_per_word
- 1);
288 command
&= ~(SPI_RX_EN
| SPI_TX_EN
);
291 tsd
->cur_direction
= 0;
293 command
|= SPI_RX_EN
;
294 tsd
->cur_direction
|= DATA_DIR_RX
;
297 command
|= SPI_TX_EN
;
298 tsd
->cur_direction
|= DATA_DIR_TX
;
300 tegra_sflash_writel(tsd
, command
, SPI_COMMAND
);
301 tsd
->command_reg
= command
;
303 return tegra_sflash_start_cpu_based_transfer(tsd
, t
);
306 static int tegra_sflash_transfer_one_message(struct spi_master
*master
,
307 struct spi_message
*msg
)
309 bool is_first_msg
= true;
311 struct tegra_sflash_data
*tsd
= spi_master_get_devdata(master
);
312 struct spi_transfer
*xfer
;
313 struct spi_device
*spi
= msg
->spi
;
317 msg
->actual_length
= 0;
318 single_xfer
= list_is_singular(&msg
->transfers
);
319 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
320 reinit_completion(&tsd
->xfer_completion
);
321 ret
= tegra_sflash_start_transfer_one(spi
, xfer
,
322 is_first_msg
, single_xfer
);
325 "spi can not start transfer, err %d\n", ret
);
328 is_first_msg
= false;
329 ret
= wait_for_completion_timeout(&tsd
->xfer_completion
,
331 if (WARN_ON(ret
== 0)) {
333 "spi transfer timeout, err %d\n", ret
);
338 if (tsd
->tx_status
|| tsd
->rx_status
) {
339 dev_err(tsd
->dev
, "Error in Transfer\n");
343 msg
->actual_length
+= xfer
->len
;
344 if (xfer
->cs_change
&&
345 (xfer
->delay_usecs
|| xfer
->delay
.value
)) {
346 tegra_sflash_writel(tsd
, tsd
->def_command_reg
,
348 spi_transfer_delay_exec(xfer
);
353 tegra_sflash_writel(tsd
, tsd
->def_command_reg
, SPI_COMMAND
);
355 spi_finalize_current_message(master
);
359 static irqreturn_t
handle_cpu_based_xfer(struct tegra_sflash_data
*tsd
)
361 struct spi_transfer
*t
= tsd
->curr_xfer
;
363 spin_lock(&tsd
->lock
);
364 if (tsd
->tx_status
|| tsd
->rx_status
|| (tsd
->status_reg
& SPI_BSY
)) {
366 "CpuXfer ERROR bit set 0x%x\n", tsd
->status_reg
);
368 "CpuXfer 0x%08x:0x%08x\n", tsd
->command_reg
,
369 tsd
->dma_control_reg
);
370 reset_control_assert(tsd
->rst
);
372 reset_control_deassert(tsd
->rst
);
373 complete(&tsd
->xfer_completion
);
377 if (tsd
->cur_direction
& DATA_DIR_RX
)
378 tegra_sflash_read_rx_fifo_to_client_rxbuf(tsd
, t
);
380 if (tsd
->cur_direction
& DATA_DIR_TX
)
381 tsd
->cur_pos
= tsd
->cur_tx_pos
;
383 tsd
->cur_pos
= tsd
->cur_rx_pos
;
385 if (tsd
->cur_pos
== t
->len
) {
386 complete(&tsd
->xfer_completion
);
390 tegra_sflash_calculate_curr_xfer_param(tsd
->cur_spi
, tsd
, t
);
391 tegra_sflash_start_cpu_based_transfer(tsd
, t
);
393 spin_unlock(&tsd
->lock
);
397 static irqreturn_t
tegra_sflash_isr(int irq
, void *context_data
)
399 struct tegra_sflash_data
*tsd
= context_data
;
401 tsd
->status_reg
= tegra_sflash_readl(tsd
, SPI_STATUS
);
402 if (tsd
->cur_direction
& DATA_DIR_TX
)
403 tsd
->tx_status
= tsd
->status_reg
& SPI_TX_OVF
;
405 if (tsd
->cur_direction
& DATA_DIR_RX
)
406 tsd
->rx_status
= tsd
->status_reg
& SPI_RX_UNF
;
407 tegra_sflash_clear_status(tsd
);
409 return handle_cpu_based_xfer(tsd
);
412 static const struct of_device_id tegra_sflash_of_match
[] = {
413 { .compatible
= "nvidia,tegra20-sflash", },
416 MODULE_DEVICE_TABLE(of
, tegra_sflash_of_match
);
418 static int tegra_sflash_probe(struct platform_device
*pdev
)
420 struct spi_master
*master
;
421 struct tegra_sflash_data
*tsd
;
423 const struct of_device_id
*match
;
425 match
= of_match_device(tegra_sflash_of_match
, &pdev
->dev
);
427 dev_err(&pdev
->dev
, "Error: No device match found\n");
431 master
= spi_alloc_master(&pdev
->dev
, sizeof(*tsd
));
433 dev_err(&pdev
->dev
, "master allocation failed\n");
437 /* the spi->mode bits understood by this driver: */
438 master
->mode_bits
= SPI_CPOL
| SPI_CPHA
;
439 master
->transfer_one_message
= tegra_sflash_transfer_one_message
;
440 master
->auto_runtime_pm
= true;
441 master
->num_chipselect
= MAX_CHIP_SELECT
;
443 platform_set_drvdata(pdev
, master
);
444 tsd
= spi_master_get_devdata(master
);
445 tsd
->master
= master
;
446 tsd
->dev
= &pdev
->dev
;
447 spin_lock_init(&tsd
->lock
);
449 if (of_property_read_u32(tsd
->dev
->of_node
, "spi-max-frequency",
450 &master
->max_speed_hz
))
451 master
->max_speed_hz
= 25000000; /* 25MHz */
453 tsd
->base
= devm_platform_ioremap_resource(pdev
, 0);
454 if (IS_ERR(tsd
->base
)) {
455 ret
= PTR_ERR(tsd
->base
);
456 goto exit_free_master
;
459 tsd
->irq
= platform_get_irq(pdev
, 0);
460 ret
= request_irq(tsd
->irq
, tegra_sflash_isr
, 0,
461 dev_name(&pdev
->dev
), tsd
);
463 dev_err(&pdev
->dev
, "Failed to register ISR for IRQ %d\n",
465 goto exit_free_master
;
468 tsd
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
469 if (IS_ERR(tsd
->clk
)) {
470 dev_err(&pdev
->dev
, "can not get clock\n");
471 ret
= PTR_ERR(tsd
->clk
);
475 tsd
->rst
= devm_reset_control_get_exclusive(&pdev
->dev
, "spi");
476 if (IS_ERR(tsd
->rst
)) {
477 dev_err(&pdev
->dev
, "can not get reset\n");
478 ret
= PTR_ERR(tsd
->rst
);
482 init_completion(&tsd
->xfer_completion
);
483 pm_runtime_enable(&pdev
->dev
);
484 if (!pm_runtime_enabled(&pdev
->dev
)) {
485 ret
= tegra_sflash_runtime_resume(&pdev
->dev
);
487 goto exit_pm_disable
;
490 ret
= pm_runtime_get_sync(&pdev
->dev
);
492 dev_err(&pdev
->dev
, "pm runtime get failed, e = %d\n", ret
);
493 pm_runtime_put_noidle(&pdev
->dev
);
494 goto exit_pm_disable
;
497 /* Reset controller */
498 reset_control_assert(tsd
->rst
);
500 reset_control_deassert(tsd
->rst
);
502 tsd
->def_command_reg
= SPI_M_S
| SPI_CS_SW
;
503 tegra_sflash_writel(tsd
, tsd
->def_command_reg
, SPI_COMMAND
);
504 pm_runtime_put(&pdev
->dev
);
506 master
->dev
.of_node
= pdev
->dev
.of_node
;
507 ret
= devm_spi_register_master(&pdev
->dev
, master
);
509 dev_err(&pdev
->dev
, "can not register to master err %d\n", ret
);
510 goto exit_pm_disable
;
515 pm_runtime_disable(&pdev
->dev
);
516 if (!pm_runtime_status_suspended(&pdev
->dev
))
517 tegra_sflash_runtime_suspend(&pdev
->dev
);
519 free_irq(tsd
->irq
, tsd
);
521 spi_master_put(master
);
525 static int tegra_sflash_remove(struct platform_device
*pdev
)
527 struct spi_master
*master
= platform_get_drvdata(pdev
);
528 struct tegra_sflash_data
*tsd
= spi_master_get_devdata(master
);
530 free_irq(tsd
->irq
, tsd
);
532 pm_runtime_disable(&pdev
->dev
);
533 if (!pm_runtime_status_suspended(&pdev
->dev
))
534 tegra_sflash_runtime_suspend(&pdev
->dev
);
539 #ifdef CONFIG_PM_SLEEP
540 static int tegra_sflash_suspend(struct device
*dev
)
542 struct spi_master
*master
= dev_get_drvdata(dev
);
544 return spi_master_suspend(master
);
547 static int tegra_sflash_resume(struct device
*dev
)
549 struct spi_master
*master
= dev_get_drvdata(dev
);
550 struct tegra_sflash_data
*tsd
= spi_master_get_devdata(master
);
553 ret
= pm_runtime_get_sync(dev
);
555 pm_runtime_put_noidle(dev
);
556 dev_err(dev
, "pm runtime failed, e = %d\n", ret
);
559 tegra_sflash_writel(tsd
, tsd
->command_reg
, SPI_COMMAND
);
562 return spi_master_resume(master
);
566 static int tegra_sflash_runtime_suspend(struct device
*dev
)
568 struct spi_master
*master
= dev_get_drvdata(dev
);
569 struct tegra_sflash_data
*tsd
= spi_master_get_devdata(master
);
571 /* Flush all write which are in PPSB queue by reading back */
572 tegra_sflash_readl(tsd
, SPI_COMMAND
);
574 clk_disable_unprepare(tsd
->clk
);
578 static int tegra_sflash_runtime_resume(struct device
*dev
)
580 struct spi_master
*master
= dev_get_drvdata(dev
);
581 struct tegra_sflash_data
*tsd
= spi_master_get_devdata(master
);
584 ret
= clk_prepare_enable(tsd
->clk
);
586 dev_err(tsd
->dev
, "clk_prepare failed: %d\n", ret
);
592 static const struct dev_pm_ops slink_pm_ops
= {
593 SET_RUNTIME_PM_OPS(tegra_sflash_runtime_suspend
,
594 tegra_sflash_runtime_resume
, NULL
)
595 SET_SYSTEM_SLEEP_PM_OPS(tegra_sflash_suspend
, tegra_sflash_resume
)
597 static struct platform_driver tegra_sflash_driver
= {
599 .name
= "spi-tegra-sflash",
601 .of_match_table
= tegra_sflash_of_match
,
603 .probe
= tegra_sflash_probe
,
604 .remove
= tegra_sflash_remove
,
606 module_platform_driver(tegra_sflash_driver
);
608 MODULE_ALIAS("platform:spi-tegra-sflash");
609 MODULE_DESCRIPTION("NVIDIA Tegra20 Serial Flash Controller Driver");
610 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
611 MODULE_LICENSE("GPL v2");