2 * SPI driver for Nvidia's Tegra20 Serial Flash Controller.
4 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
6 * Author: Laxman Dewangan <ldewangan@nvidia.com>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms and conditions of the GNU General Public License,
10 * version 2, as published by the Free Software Foundation.
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include <linux/clk.h>
22 #include <linux/completion.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
28 #include <linux/kernel.h>
29 #include <linux/kthread.h>
30 #include <linux/module.h>
31 #include <linux/platform_device.h>
32 #include <linux/pm_runtime.h>
34 #include <linux/of_device.h>
35 #include <linux/spi/spi.h>
36 #include <linux/spi/spi-tegra.h>
39 #define SPI_COMMAND 0x000
40 #define SPI_GO BIT(30)
41 #define SPI_M_S BIT(28)
42 #define SPI_ACTIVE_SCLK_MASK (0x3 << 26)
43 #define SPI_ACTIVE_SCLK_DRIVE_LOW (0 << 26)
44 #define SPI_ACTIVE_SCLK_DRIVE_HIGH (1 << 26)
45 #define SPI_ACTIVE_SCLK_PULL_LOW (2 << 26)
46 #define SPI_ACTIVE_SCLK_PULL_HIGH (3 << 26)
48 #define SPI_CK_SDA_FALLING (1 << 21)
49 #define SPI_CK_SDA_RISING (0 << 21)
50 #define SPI_CK_SDA_MASK (1 << 21)
51 #define SPI_ACTIVE_SDA (0x3 << 18)
52 #define SPI_ACTIVE_SDA_DRIVE_LOW (0 << 18)
53 #define SPI_ACTIVE_SDA_DRIVE_HIGH (1 << 18)
54 #define SPI_ACTIVE_SDA_PULL_LOW (2 << 18)
55 #define SPI_ACTIVE_SDA_PULL_HIGH (3 << 18)
57 #define SPI_CS_POL_INVERT BIT(16)
58 #define SPI_TX_EN BIT(15)
59 #define SPI_RX_EN BIT(14)
60 #define SPI_CS_VAL_HIGH BIT(13)
61 #define SPI_CS_VAL_LOW 0x0
62 #define SPI_CS_SW BIT(12)
64 #define SPI_CS_DELAY_MASK (7 << 9)
65 #define SPI_CS3_EN BIT(8)
66 #define SPI_CS2_EN BIT(7)
67 #define SPI_CS1_EN BIT(6)
68 #define SPI_CS0_EN BIT(5)
70 #define SPI_CS_MASK (SPI_CS3_EN | SPI_CS2_EN | \
71 SPI_CS1_EN | SPI_CS0_EN)
72 #define SPI_BIT_LENGTH(x) (((x) & 0x1f) << 0)
74 #define SPI_MODES (SPI_ACTIVE_SCLK_MASK | SPI_CK_SDA_MASK)
76 #define SPI_STATUS 0x004
77 #define SPI_BSY BIT(31)
78 #define SPI_RDY BIT(30)
79 #define SPI_TXF_FLUSH BIT(29)
80 #define SPI_RXF_FLUSH BIT(28)
81 #define SPI_RX_UNF BIT(27)
82 #define SPI_TX_OVF BIT(26)
83 #define SPI_RXF_EMPTY BIT(25)
84 #define SPI_RXF_FULL BIT(24)
85 #define SPI_TXF_EMPTY BIT(23)
86 #define SPI_TXF_FULL BIT(22)
87 #define SPI_BLK_CNT(count) (((count) & 0xffff) + 1)
89 #define SPI_FIFO_ERROR (SPI_RX_UNF | SPI_TX_OVF)
90 #define SPI_FIFO_EMPTY (SPI_TX_EMPTY | SPI_RX_EMPTY)
92 #define SPI_RX_CMP 0x8
93 #define SPI_DMA_CTL 0x0C
94 #define SPI_DMA_EN BIT(31)
95 #define SPI_IE_RXC BIT(27)
96 #define SPI_IE_TXC BIT(26)
97 #define SPI_PACKED BIT(20)
98 #define SPI_RX_TRIG_MASK (0x3 << 18)
99 #define SPI_RX_TRIG_1W (0x0 << 18)
100 #define SPI_RX_TRIG_4W (0x1 << 18)
101 #define SPI_TX_TRIG_MASK (0x3 << 16)
102 #define SPI_TX_TRIG_1W (0x0 << 16)
103 #define SPI_TX_TRIG_4W (0x1 << 16)
104 #define SPI_DMA_BLK_COUNT(count) (((count) - 1) & 0xFFFF);
106 #define SPI_TX_FIFO 0x10
107 #define SPI_RX_FIFO 0x20
109 #define DATA_DIR_TX (1 << 0)
110 #define DATA_DIR_RX (1 << 1)
112 #define MAX_CHIP_SELECT 4
113 #define SPI_FIFO_DEPTH 4
114 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
116 struct tegra_sflash_data {
118 struct spi_master *master;
124 u32 spi_max_frequency;
127 struct spi_device *cur_spi;
130 unsigned bytes_per_word;
131 unsigned cur_direction;
132 unsigned curr_xfer_words;
145 struct completion xfer_completion;
146 struct spi_transfer *curr_xfer;
149 static int tegra_sflash_runtime_suspend(struct device *dev);
150 static int tegra_sflash_runtime_resume(struct device *dev);
152 static inline unsigned long tegra_sflash_readl(struct tegra_sflash_data *tsd,
155 return readl(tsd->base + reg);
158 static inline void tegra_sflash_writel(struct tegra_sflash_data *tsd,
159 unsigned long val, unsigned long reg)
161 writel(val, tsd->base + reg);
164 static void tegra_sflash_clear_status(struct tegra_sflash_data *tsd)
166 /* Write 1 to clear status register */
167 tegra_sflash_writel(tsd, SPI_RDY | SPI_FIFO_ERROR, SPI_STATUS);
170 static unsigned tegra_sflash_calculate_curr_xfer_param(
171 struct spi_device *spi, struct tegra_sflash_data *tsd,
172 struct spi_transfer *t)
174 unsigned remain_len = t->len - tsd->cur_pos;
177 tsd->bytes_per_word = (t->bits_per_word - 1) / 8 + 1;
178 max_word = remain_len / tsd->bytes_per_word;
179 if (max_word > SPI_FIFO_DEPTH)
180 max_word = SPI_FIFO_DEPTH;
181 tsd->curr_xfer_words = max_word;
185 static unsigned tegra_sflash_fill_tx_fifo_from_client_txbuf(
186 struct tegra_sflash_data *tsd, struct spi_transfer *t)
189 unsigned long status;
190 unsigned max_n_32bit = tsd->curr_xfer_words;
191 u8 *tx_buf = (u8 *)t->tx_buf + tsd->cur_tx_pos;
193 if (max_n_32bit > SPI_FIFO_DEPTH)
194 max_n_32bit = SPI_FIFO_DEPTH;
195 nbytes = max_n_32bit * tsd->bytes_per_word;
197 status = tegra_sflash_readl(tsd, SPI_STATUS);
198 while (!(status & SPI_TXF_FULL)) {
202 for (i = 0; nbytes && (i < tsd->bytes_per_word);
204 x |= ((*tx_buf++) << i*8);
205 tegra_sflash_writel(tsd, x, SPI_TX_FIFO);
209 status = tegra_sflash_readl(tsd, SPI_STATUS);
211 tsd->cur_tx_pos += max_n_32bit * tsd->bytes_per_word;
215 static int tegra_sflash_read_rx_fifo_to_client_rxbuf(
216 struct tegra_sflash_data *tsd, struct spi_transfer *t)
218 unsigned long status;
219 unsigned int read_words = 0;
220 u8 *rx_buf = (u8 *)t->rx_buf + tsd->cur_rx_pos;
222 status = tegra_sflash_readl(tsd, SPI_STATUS);
223 while (!(status & SPI_RXF_EMPTY)) {
227 x = tegra_sflash_readl(tsd, SPI_RX_FIFO);
228 for (i = 0; (i < tsd->bytes_per_word); i++)
229 *rx_buf++ = (x >> (i*8)) & 0xFF;
231 status = tegra_sflash_readl(tsd, SPI_STATUS);
233 tsd->cur_rx_pos += read_words * tsd->bytes_per_word;
237 static int tegra_sflash_start_cpu_based_transfer(
238 struct tegra_sflash_data *tsd, struct spi_transfer *t)
240 unsigned long val = 0;
243 if (tsd->cur_direction & DATA_DIR_TX)
246 if (tsd->cur_direction & DATA_DIR_RX)
249 tegra_sflash_writel(tsd, val, SPI_DMA_CTL);
250 tsd->dma_control_reg = val;
252 if (tsd->cur_direction & DATA_DIR_TX)
253 cur_words = tegra_sflash_fill_tx_fifo_from_client_txbuf(tsd, t);
255 cur_words = tsd->curr_xfer_words;
256 val |= SPI_DMA_BLK_COUNT(cur_words);
257 tegra_sflash_writel(tsd, val, SPI_DMA_CTL);
258 tsd->dma_control_reg = val;
260 tegra_sflash_writel(tsd, val, SPI_DMA_CTL);
264 static int tegra_sflash_start_transfer_one(struct spi_device *spi,
265 struct spi_transfer *t, bool is_first_of_msg,
268 struct tegra_sflash_data *tsd = spi_master_get_devdata(spi->master);
270 unsigned long command;
273 if (speed != tsd->cur_speed) {
274 clk_set_rate(tsd->clk, speed);
275 tsd->cur_speed = speed;
283 tegra_sflash_calculate_curr_xfer_param(spi, tsd, t);
284 if (is_first_of_msg) {
285 command = tsd->def_command_reg;
286 command |= SPI_BIT_LENGTH(t->bits_per_word - 1);
287 command |= SPI_CS_VAL_HIGH;
289 command &= ~SPI_MODES;
290 if (spi->mode & SPI_CPHA)
291 command |= SPI_CK_SDA_FALLING;
293 if (spi->mode & SPI_CPOL)
294 command |= SPI_ACTIVE_SCLK_DRIVE_HIGH;
296 command |= SPI_ACTIVE_SCLK_DRIVE_LOW;
297 command |= SPI_CS0_EN << spi->chip_select;
299 command = tsd->command_reg;
300 command &= ~SPI_BIT_LENGTH(~0);
301 command |= SPI_BIT_LENGTH(t->bits_per_word - 1);
302 command &= ~(SPI_RX_EN | SPI_TX_EN);
305 tsd->cur_direction = 0;
307 command |= SPI_RX_EN;
308 tsd->cur_direction |= DATA_DIR_RX;
311 command |= SPI_TX_EN;
312 tsd->cur_direction |= DATA_DIR_TX;
314 tegra_sflash_writel(tsd, command, SPI_COMMAND);
315 tsd->command_reg = command;
317 return tegra_sflash_start_cpu_based_transfer(tsd, t);
320 static int tegra_sflash_setup(struct spi_device *spi)
322 struct tegra_sflash_data *tsd = spi_master_get_devdata(spi->master);
324 /* Set speed to the spi max fequency if spi device has not set */
325 spi->max_speed_hz = spi->max_speed_hz ? : tsd->spi_max_frequency;
329 static int tegra_sflash_transfer_one_message(struct spi_master *master,
330 struct spi_message *msg)
332 bool is_first_msg = true;
334 struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
335 struct spi_transfer *xfer;
336 struct spi_device *spi = msg->spi;
339 ret = pm_runtime_get_sync(tsd->dev);
341 dev_err(tsd->dev, "pm_runtime_get() failed, err = %d\n", ret);
346 msg->actual_length = 0;
347 single_xfer = list_is_singular(&msg->transfers);
348 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
349 INIT_COMPLETION(tsd->xfer_completion);
350 ret = tegra_sflash_start_transfer_one(spi, xfer,
351 is_first_msg, single_xfer);
354 "spi can not start transfer, err %d\n", ret);
357 is_first_msg = false;
358 ret = wait_for_completion_timeout(&tsd->xfer_completion,
360 if (WARN_ON(ret == 0)) {
362 "spi trasfer timeout, err %d\n", ret);
367 if (tsd->tx_status || tsd->rx_status) {
368 dev_err(tsd->dev, "Error in Transfer\n");
372 msg->actual_length += xfer->len;
373 if (xfer->cs_change && xfer->delay_usecs) {
374 tegra_sflash_writel(tsd, tsd->def_command_reg,
376 udelay(xfer->delay_usecs);
381 tegra_sflash_writel(tsd, tsd->def_command_reg, SPI_COMMAND);
383 spi_finalize_current_message(master);
384 pm_runtime_put(tsd->dev);
388 static irqreturn_t handle_cpu_based_xfer(struct tegra_sflash_data *tsd)
390 struct spi_transfer *t = tsd->curr_xfer;
393 spin_lock_irqsave(&tsd->lock, flags);
394 if (tsd->tx_status || tsd->rx_status || (tsd->status_reg & SPI_BSY)) {
396 "CpuXfer ERROR bit set 0x%x\n", tsd->status_reg);
398 "CpuXfer 0x%08x:0x%08x\n", tsd->command_reg,
399 tsd->dma_control_reg);
400 tegra_periph_reset_assert(tsd->clk);
402 tegra_periph_reset_deassert(tsd->clk);
403 complete(&tsd->xfer_completion);
407 if (tsd->cur_direction & DATA_DIR_RX)
408 tegra_sflash_read_rx_fifo_to_client_rxbuf(tsd, t);
410 if (tsd->cur_direction & DATA_DIR_TX)
411 tsd->cur_pos = tsd->cur_tx_pos;
413 tsd->cur_pos = tsd->cur_rx_pos;
415 if (tsd->cur_pos == t->len) {
416 complete(&tsd->xfer_completion);
420 tegra_sflash_calculate_curr_xfer_param(tsd->cur_spi, tsd, t);
421 tegra_sflash_start_cpu_based_transfer(tsd, t);
423 spin_unlock_irqrestore(&tsd->lock, flags);
427 static irqreturn_t tegra_sflash_isr(int irq, void *context_data)
429 struct tegra_sflash_data *tsd = context_data;
431 tsd->status_reg = tegra_sflash_readl(tsd, SPI_STATUS);
432 if (tsd->cur_direction & DATA_DIR_TX)
433 tsd->tx_status = tsd->status_reg & SPI_TX_OVF;
435 if (tsd->cur_direction & DATA_DIR_RX)
436 tsd->rx_status = tsd->status_reg & SPI_RX_UNF;
437 tegra_sflash_clear_status(tsd);
439 return handle_cpu_based_xfer(tsd);
442 static struct tegra_spi_platform_data *tegra_sflash_parse_dt(
443 struct platform_device *pdev)
445 struct tegra_spi_platform_data *pdata;
446 struct device_node *np = pdev->dev.of_node;
449 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
451 dev_err(&pdev->dev, "Memory alloc for pdata failed\n");
455 if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
456 pdata->spi_max_frequency = max_freq;
461 static struct of_device_id tegra_sflash_of_match[] = {
462 { .compatible = "nvidia,tegra20-sflash", },
465 MODULE_DEVICE_TABLE(of, tegra_sflash_of_match);
467 static int tegra_sflash_probe(struct platform_device *pdev)
469 struct spi_master *master;
470 struct tegra_sflash_data *tsd;
472 struct tegra_spi_platform_data *pdata = pdev->dev.platform_data;
474 const struct of_device_id *match;
476 match = of_match_device(of_match_ptr(tegra_sflash_of_match),
479 dev_err(&pdev->dev, "Error: No device match found\n");
483 if (!pdata && pdev->dev.of_node)
484 pdata = tegra_sflash_parse_dt(pdev);
487 dev_err(&pdev->dev, "No platform data, exiting\n");
491 if (!pdata->spi_max_frequency)
492 pdata->spi_max_frequency = 25000000; /* 25MHz */
494 master = spi_alloc_master(&pdev->dev, sizeof(*tsd));
496 dev_err(&pdev->dev, "master allocation failed\n");
500 /* the spi->mode bits understood by this driver: */
501 master->mode_bits = SPI_CPOL | SPI_CPHA;
502 master->setup = tegra_sflash_setup;
503 master->transfer_one_message = tegra_sflash_transfer_one_message;
504 master->num_chipselect = MAX_CHIP_SELECT;
505 master->bus_num = -1;
507 dev_set_drvdata(&pdev->dev, master);
508 tsd = spi_master_get_devdata(master);
509 tsd->master = master;
510 tsd->dev = &pdev->dev;
511 spin_lock_init(&tsd->lock);
513 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
515 dev_err(&pdev->dev, "No IO memory resource\n");
517 goto exit_free_master;
519 tsd->base = devm_ioremap_resource(&pdev->dev, r);
520 if (IS_ERR(tsd->base)) {
521 ret = PTR_ERR(tsd->base);
522 goto exit_free_master;
525 tsd->irq = platform_get_irq(pdev, 0);
526 ret = request_irq(tsd->irq, tegra_sflash_isr, 0,
527 dev_name(&pdev->dev), tsd);
529 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
531 goto exit_free_master;
534 tsd->clk = devm_clk_get(&pdev->dev, "spi");
535 if (IS_ERR(tsd->clk)) {
536 dev_err(&pdev->dev, "can not get clock\n");
537 ret = PTR_ERR(tsd->clk);
541 tsd->spi_max_frequency = pdata->spi_max_frequency;
542 init_completion(&tsd->xfer_completion);
543 pm_runtime_enable(&pdev->dev);
544 if (!pm_runtime_enabled(&pdev->dev)) {
545 ret = tegra_sflash_runtime_resume(&pdev->dev);
547 goto exit_pm_disable;
550 ret = pm_runtime_get_sync(&pdev->dev);
552 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
553 goto exit_pm_disable;
556 /* Reset controller */
557 tegra_periph_reset_assert(tsd->clk);
559 tegra_periph_reset_deassert(tsd->clk);
561 tsd->def_command_reg = SPI_M_S | SPI_CS_SW;
562 tegra_sflash_writel(tsd, tsd->def_command_reg, SPI_COMMAND);
563 pm_runtime_put(&pdev->dev);
565 master->dev.of_node = pdev->dev.of_node;
566 ret = spi_register_master(master);
568 dev_err(&pdev->dev, "can not register to master err %d\n", ret);
569 goto exit_pm_disable;
574 pm_runtime_disable(&pdev->dev);
575 if (!pm_runtime_status_suspended(&pdev->dev))
576 tegra_sflash_runtime_suspend(&pdev->dev);
578 free_irq(tsd->irq, tsd);
580 spi_master_put(master);
584 static int tegra_sflash_remove(struct platform_device *pdev)
586 struct spi_master *master = dev_get_drvdata(&pdev->dev);
587 struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
589 free_irq(tsd->irq, tsd);
590 spi_unregister_master(master);
592 pm_runtime_disable(&pdev->dev);
593 if (!pm_runtime_status_suspended(&pdev->dev))
594 tegra_sflash_runtime_suspend(&pdev->dev);
599 #ifdef CONFIG_PM_SLEEP
600 static int tegra_sflash_suspend(struct device *dev)
602 struct spi_master *master = dev_get_drvdata(dev);
604 return spi_master_suspend(master);
607 static int tegra_sflash_resume(struct device *dev)
609 struct spi_master *master = dev_get_drvdata(dev);
610 struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
613 ret = pm_runtime_get_sync(dev);
615 dev_err(dev, "pm runtime failed, e = %d\n", ret);
618 tegra_sflash_writel(tsd, tsd->command_reg, SPI_COMMAND);
621 return spi_master_resume(master);
625 static int tegra_sflash_runtime_suspend(struct device *dev)
627 struct spi_master *master = dev_get_drvdata(dev);
628 struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
630 /* Flush all write which are in PPSB queue by reading back */
631 tegra_sflash_readl(tsd, SPI_COMMAND);
633 clk_disable_unprepare(tsd->clk);
637 static int tegra_sflash_runtime_resume(struct device *dev)
639 struct spi_master *master = dev_get_drvdata(dev);
640 struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
643 ret = clk_prepare_enable(tsd->clk);
645 dev_err(tsd->dev, "clk_prepare failed: %d\n", ret);
651 static const struct dev_pm_ops slink_pm_ops = {
652 SET_RUNTIME_PM_OPS(tegra_sflash_runtime_suspend,
653 tegra_sflash_runtime_resume, NULL)
654 SET_SYSTEM_SLEEP_PM_OPS(tegra_sflash_suspend, tegra_sflash_resume)
656 static struct platform_driver tegra_sflash_driver = {
658 .name = "spi-tegra-sflash",
659 .owner = THIS_MODULE,
661 .of_match_table = of_match_ptr(tegra_sflash_of_match),
663 .probe = tegra_sflash_probe,
664 .remove = tegra_sflash_remove,
666 module_platform_driver(tegra_sflash_driver);
668 MODULE_ALIAS("platform:spi-tegra-sflash");
669 MODULE_DESCRIPTION("NVIDIA Tegra20 Serial Flash Controller Driver");
670 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
671 MODULE_LICENSE("GPL v2");