Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
  1/*
  2 * SPI bus driver for CSR SiRFprimaII
  3 *
  4 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
  5 *
  6 * Licensed under GPLv2 or later.
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/kernel.h>
 11#include <linux/slab.h>
 12#include <linux/clk.h>
 13#include <linux/interrupt.h>
 14#include <linux/io.h>
 15#include <linux/of.h>
 16#include <linux/bitops.h>
 17#include <linux/err.h>
 18#include <linux/platform_device.h>
 19#include <linux/of_gpio.h>
 20#include <linux/spi/spi.h>
 21#include <linux/spi/spi_bitbang.h>
 22#include <linux/pinctrl/consumer.h>
 23
 24#define DRIVER_NAME "sirfsoc_spi"
 25
 26#define SIRFSOC_SPI_CTRL		0x0000
 27#define SIRFSOC_SPI_CMD			0x0004
 28#define SIRFSOC_SPI_TX_RX_EN		0x0008
 29#define SIRFSOC_SPI_INT_EN		0x000C
 30#define SIRFSOC_SPI_INT_STATUS		0x0010
 31#define SIRFSOC_SPI_TX_DMA_IO_CTRL	0x0100
 32#define SIRFSOC_SPI_TX_DMA_IO_LEN	0x0104
 33#define SIRFSOC_SPI_TXFIFO_CTRL		0x0108
 34#define SIRFSOC_SPI_TXFIFO_LEVEL_CHK	0x010C
 35#define SIRFSOC_SPI_TXFIFO_OP		0x0110
 36#define SIRFSOC_SPI_TXFIFO_STATUS	0x0114
 37#define SIRFSOC_SPI_TXFIFO_DATA		0x0118
 38#define SIRFSOC_SPI_RX_DMA_IO_CTRL	0x0120
 39#define SIRFSOC_SPI_RX_DMA_IO_LEN	0x0124
 40#define SIRFSOC_SPI_RXFIFO_CTRL		0x0128
 41#define SIRFSOC_SPI_RXFIFO_LEVEL_CHK	0x012C
 42#define SIRFSOC_SPI_RXFIFO_OP		0x0130
 43#define SIRFSOC_SPI_RXFIFO_STATUS	0x0134
 44#define SIRFSOC_SPI_RXFIFO_DATA		0x0138
 45#define SIRFSOC_SPI_DUMMY_DELAY_CTL	0x0144
 46
 47/* SPI CTRL register defines */
 48#define SIRFSOC_SPI_SLV_MODE		BIT(16)
 49#define SIRFSOC_SPI_CMD_MODE		BIT(17)
 50#define SIRFSOC_SPI_CS_IO_OUT		BIT(18)
 51#define SIRFSOC_SPI_CS_IO_MODE		BIT(19)
 52#define SIRFSOC_SPI_CLK_IDLE_STAT	BIT(20)
 53#define SIRFSOC_SPI_CS_IDLE_STAT	BIT(21)
 54#define SIRFSOC_SPI_TRAN_MSB		BIT(22)
 55#define SIRFSOC_SPI_DRV_POS_EDGE	BIT(23)
 56#define SIRFSOC_SPI_CS_HOLD_TIME	BIT(24)
 57#define SIRFSOC_SPI_CLK_SAMPLE_MODE	BIT(25)
 58#define SIRFSOC_SPI_TRAN_DAT_FORMAT_8	(0 << 26)
 59#define SIRFSOC_SPI_TRAN_DAT_FORMAT_12	(1 << 26)
 60#define SIRFSOC_SPI_TRAN_DAT_FORMAT_16	(2 << 26)
 61#define SIRFSOC_SPI_TRAN_DAT_FORMAT_32	(3 << 26)
 62#define SIRFSOC_SPI_CMD_BYTE_NUM(x)		((x & 3) << 28)
 63#define SIRFSOC_SPI_ENA_AUTO_CLR		BIT(30)
 64#define SIRFSOC_SPI_MUL_DAT_MODE		BIT(31)
 65
 66/* Interrupt Enable */
 67#define SIRFSOC_SPI_RX_DONE_INT_EN		BIT(0)
 68#define SIRFSOC_SPI_TX_DONE_INT_EN		BIT(1)
 69#define SIRFSOC_SPI_RX_OFLOW_INT_EN		BIT(2)
 70#define SIRFSOC_SPI_TX_UFLOW_INT_EN		BIT(3)
 71#define SIRFSOC_SPI_RX_IO_DMA_INT_EN	BIT(4)
 72#define SIRFSOC_SPI_TX_IO_DMA_INT_EN	BIT(5)
 73#define SIRFSOC_SPI_RXFIFO_FULL_INT_EN	BIT(6)
 74#define SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN	BIT(7)
 75#define SIRFSOC_SPI_RXFIFO_THD_INT_EN	BIT(8)
 76#define SIRFSOC_SPI_TXFIFO_THD_INT_EN	BIT(9)
 77#define SIRFSOC_SPI_FRM_END_INT_EN	BIT(10)
 78
 79#define SIRFSOC_SPI_INT_MASK_ALL		0x1FFF
 80
 81/* Interrupt status */
 82#define SIRFSOC_SPI_RX_DONE		BIT(0)
 83#define SIRFSOC_SPI_TX_DONE		BIT(1)
 84#define SIRFSOC_SPI_RX_OFLOW		BIT(2)
 85#define SIRFSOC_SPI_TX_UFLOW		BIT(3)
 86#define SIRFSOC_SPI_RX_FIFO_FULL	BIT(6)
 87#define SIRFSOC_SPI_TXFIFO_EMPTY	BIT(7)
 88#define SIRFSOC_SPI_RXFIFO_THD_REACH	BIT(8)
 89#define SIRFSOC_SPI_TXFIFO_THD_REACH	BIT(9)
 90#define SIRFSOC_SPI_FRM_END		BIT(10)
 91
 92/* TX RX enable */
 93#define SIRFSOC_SPI_RX_EN		BIT(0)
 94#define SIRFSOC_SPI_TX_EN		BIT(1)
 95#define SIRFSOC_SPI_CMD_TX_EN		BIT(2)
 96
 97#define SIRFSOC_SPI_IO_MODE_SEL		BIT(0)
 98#define SIRFSOC_SPI_RX_DMA_FLUSH	BIT(2)
 99
100/* FIFO OPs */
101#define SIRFSOC_SPI_FIFO_RESET		BIT(0)
102#define SIRFSOC_SPI_FIFO_START		BIT(1)
103
104/* FIFO CTRL */
105#define SIRFSOC_SPI_FIFO_WIDTH_BYTE	(0 << 0)
106#define SIRFSOC_SPI_FIFO_WIDTH_WORD	(1 << 0)
107#define SIRFSOC_SPI_FIFO_WIDTH_DWORD	(2 << 0)
108
109/* FIFO Status */
110#define	SIRFSOC_SPI_FIFO_LEVEL_MASK	0xFF
111#define SIRFSOC_SPI_FIFO_FULL		BIT(8)
112#define SIRFSOC_SPI_FIFO_EMPTY		BIT(9)
113
114/* 256 bytes rx/tx FIFO */
115#define SIRFSOC_SPI_FIFO_SIZE		256
116#define SIRFSOC_SPI_DAT_FRM_LEN_MAX	(64 * 1024)
117
118#define SIRFSOC_SPI_FIFO_SC(x)		((x) & 0x3F)
119#define SIRFSOC_SPI_FIFO_LC(x)		(((x) & 0x3F) << 10)
120#define SIRFSOC_SPI_FIFO_HC(x)		(((x) & 0x3F) << 20)
121#define SIRFSOC_SPI_FIFO_THD(x)		(((x) & 0xFF) << 2)
122
123struct sirfsoc_spi {
124	struct spi_bitbang bitbang;
125	struct completion done;
126
127	void __iomem *base;
128	u32 ctrl_freq;  /* SPI controller clock speed */
129	struct clk *clk;
130	struct pinctrl *p;
131
132	/* rx & tx bufs from the spi_transfer */
133	const void *tx;
134	void *rx;
135
136	/* place received word into rx buffer */
137	void (*rx_word) (struct sirfsoc_spi *);
138	/* get word from tx buffer for sending */
139	void (*tx_word) (struct sirfsoc_spi *);
140
141	/* number of words left to be tranmitted/received */
142	unsigned int left_tx_cnt;
143	unsigned int left_rx_cnt;
144
145	/* tasklet to push tx msg into FIFO */
146	struct tasklet_struct tasklet_tx;
147
148	int chipselect[0];
149};
150
151static void spi_sirfsoc_rx_word_u8(struct sirfsoc_spi *sspi)
152{
153	u32 data;
154	u8 *rx = sspi->rx;
155
156	data = readl(sspi->base + SIRFSOC_SPI_RXFIFO_DATA);
157
158	if (rx) {
159		*rx++ = (u8) data;
160		sspi->rx = rx;
161	}
162
163	sspi->left_rx_cnt--;
164}
165
166static void spi_sirfsoc_tx_word_u8(struct sirfsoc_spi *sspi)
167{
168	u32 data = 0;
169	const u8 *tx = sspi->tx;
170
171	if (tx) {
172		data = *tx++;
173		sspi->tx = tx;
174	}
175
176	writel(data, sspi->base + SIRFSOC_SPI_TXFIFO_DATA);
177	sspi->left_tx_cnt--;
178}
179
180static void spi_sirfsoc_rx_word_u16(struct sirfsoc_spi *sspi)
181{
182	u32 data;
183	u16 *rx = sspi->rx;
184
185	data = readl(sspi->base + SIRFSOC_SPI_RXFIFO_DATA);
186
187	if (rx) {
188		*rx++ = (u16) data;
189		sspi->rx = rx;
190	}
191
192	sspi->left_rx_cnt--;
193}
194
195static void spi_sirfsoc_tx_word_u16(struct sirfsoc_spi *sspi)
196{
197	u32 data = 0;
198	const u16 *tx = sspi->tx;
199
200	if (tx) {
201		data = *tx++;
202		sspi->tx = tx;
203	}
204
205	writel(data, sspi->base + SIRFSOC_SPI_TXFIFO_DATA);
206	sspi->left_tx_cnt--;
207}
208
209static void spi_sirfsoc_rx_word_u32(struct sirfsoc_spi *sspi)
210{
211	u32 data;
212	u32 *rx = sspi->rx;
213
214	data = readl(sspi->base + SIRFSOC_SPI_RXFIFO_DATA);
215
216	if (rx) {
217		*rx++ = (u32) data;
218		sspi->rx = rx;
219	}
220
221	sspi->left_rx_cnt--;
222
223}
224
225static void spi_sirfsoc_tx_word_u32(struct sirfsoc_spi *sspi)
226{
227	u32 data = 0;
228	const u32 *tx = sspi->tx;
229
230	if (tx) {
231		data = *tx++;
232		sspi->tx = tx;
233	}
234
235	writel(data, sspi->base + SIRFSOC_SPI_TXFIFO_DATA);
236	sspi->left_tx_cnt--;
237}
238
239static void spi_sirfsoc_tasklet_tx(unsigned long arg)
240{
241	struct sirfsoc_spi *sspi = (struct sirfsoc_spi *)arg;
242
243	/* Fill Tx FIFO while there are left words to be transmitted */
244	while (!((readl(sspi->base + SIRFSOC_SPI_TXFIFO_STATUS) &
245			SIRFSOC_SPI_FIFO_FULL)) &&
246			sspi->left_tx_cnt)
247		sspi->tx_word(sspi);
248}
249
250static irqreturn_t spi_sirfsoc_irq(int irq, void *dev_id)
251{
252	struct sirfsoc_spi *sspi = dev_id;
253	u32 spi_stat = readl(sspi->base + SIRFSOC_SPI_INT_STATUS);
254
255	writel(spi_stat, sspi->base + SIRFSOC_SPI_INT_STATUS);
256
257	/* Error Conditions */
258	if (spi_stat & SIRFSOC_SPI_RX_OFLOW ||
259			spi_stat & SIRFSOC_SPI_TX_UFLOW) {
260		complete(&sspi->done);
261		writel(0x0, sspi->base + SIRFSOC_SPI_INT_EN);
262	}
263
264	if (spi_stat & SIRFSOC_SPI_FRM_END) {
265		while (!((readl(sspi->base + SIRFSOC_SPI_RXFIFO_STATUS)
266				& SIRFSOC_SPI_FIFO_EMPTY)) &&
267				sspi->left_rx_cnt)
268			sspi->rx_word(sspi);
269
270		/* Received all words */
271		if ((sspi->left_rx_cnt == 0) && (sspi->left_tx_cnt == 0)) {
272			complete(&sspi->done);
273			writel(0x0, sspi->base + SIRFSOC_SPI_INT_EN);
274		}
275	}
276
277	if (spi_stat & SIRFSOC_SPI_RXFIFO_THD_REACH ||
278		spi_stat & SIRFSOC_SPI_TXFIFO_THD_REACH ||
279		spi_stat & SIRFSOC_SPI_RX_FIFO_FULL ||
280		spi_stat & SIRFSOC_SPI_TXFIFO_EMPTY)
281		tasklet_schedule(&sspi->tasklet_tx);
282
283	return IRQ_HANDLED;
284}
285
286static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
287{
288	struct sirfsoc_spi *sspi;
289	int timeout = t->len * 10;
290	sspi = spi_master_get_devdata(spi->master);
291
292	sspi->tx = t->tx_buf;
293	sspi->rx = t->rx_buf;
294	sspi->left_tx_cnt = sspi->left_rx_cnt = t->len;
295	INIT_COMPLETION(sspi->done);
296
297	writel(SIRFSOC_SPI_INT_MASK_ALL, sspi->base + SIRFSOC_SPI_INT_STATUS);
298
299	if (t->len == 1) {
300		writel(readl(sspi->base + SIRFSOC_SPI_CTRL) |
301			SIRFSOC_SPI_ENA_AUTO_CLR,
302			sspi->base + SIRFSOC_SPI_CTRL);
303		writel(0, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
304		writel(0, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
305	} else if ((t->len > 1) && (t->len < SIRFSOC_SPI_DAT_FRM_LEN_MAX)) {
306		writel(readl(sspi->base + SIRFSOC_SPI_CTRL) |
307				SIRFSOC_SPI_MUL_DAT_MODE |
308				SIRFSOC_SPI_ENA_AUTO_CLR,
309			sspi->base + SIRFSOC_SPI_CTRL);
310		writel(t->len - 1, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
311		writel(t->len - 1, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
312	} else {
313		writel(readl(sspi->base + SIRFSOC_SPI_CTRL),
314			sspi->base + SIRFSOC_SPI_CTRL);
315		writel(0, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
316		writel(0, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
317	}
318
319	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
320	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
321	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
322	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
323
324	/* Send the first word to trigger the whole tx/rx process */
325	sspi->tx_word(sspi);
326
327	writel(SIRFSOC_SPI_RX_OFLOW_INT_EN | SIRFSOC_SPI_TX_UFLOW_INT_EN |
328		SIRFSOC_SPI_RXFIFO_THD_INT_EN | SIRFSOC_SPI_TXFIFO_THD_INT_EN |
329		SIRFSOC_SPI_FRM_END_INT_EN | SIRFSOC_SPI_RXFIFO_FULL_INT_EN |
330		SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN, sspi->base + SIRFSOC_SPI_INT_EN);
331	writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN, sspi->base + SIRFSOC_SPI_TX_RX_EN);
332
333	if (wait_for_completion_timeout(&sspi->done, timeout) == 0)
334		dev_err(&spi->dev, "transfer timeout\n");
335
336	/* TX, RX FIFO stop */
337	writel(0, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
338	writel(0, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
339	writel(0, sspi->base + SIRFSOC_SPI_TX_RX_EN);
340	writel(0, sspi->base + SIRFSOC_SPI_INT_EN);
341
342	return t->len - sspi->left_rx_cnt;
343}
344
345static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
346{
347	struct sirfsoc_spi *sspi = spi_master_get_devdata(spi->master);
348
349	if (sspi->chipselect[spi->chip_select] == 0) {
350		u32 regval = readl(sspi->base + SIRFSOC_SPI_CTRL);
351		regval |= SIRFSOC_SPI_CS_IO_OUT;
352		switch (value) {
353		case BITBANG_CS_ACTIVE:
354			if (spi->mode & SPI_CS_HIGH)
355				regval |= SIRFSOC_SPI_CS_IO_OUT;
356			else
357				regval &= ~SIRFSOC_SPI_CS_IO_OUT;
358			break;
359		case BITBANG_CS_INACTIVE:
360			if (spi->mode & SPI_CS_HIGH)
361				regval &= ~SIRFSOC_SPI_CS_IO_OUT;
362			else
363				regval |= SIRFSOC_SPI_CS_IO_OUT;
364			break;
365		}
366		writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
367	} else {
368		int gpio = sspi->chipselect[spi->chip_select];
369		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
370	}
371}
372
373static int
374spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
375{
376	struct sirfsoc_spi *sspi;
377	u8 bits_per_word = 0;
378	int hz = 0;
379	u32 regval;
380	u32 txfifo_ctrl, rxfifo_ctrl;
381	u32 fifo_size = SIRFSOC_SPI_FIFO_SIZE / 4;
382
383	sspi = spi_master_get_devdata(spi->master);
384
385	bits_per_word = t && t->bits_per_word ? t->bits_per_word :
386		spi->bits_per_word;
387	hz = t && t->speed_hz ? t->speed_hz : spi->max_speed_hz;
388
389	/* Enable IO mode for RX, TX */
390	writel(SIRFSOC_SPI_IO_MODE_SEL, sspi->base + SIRFSOC_SPI_TX_DMA_IO_CTRL);
391	writel(SIRFSOC_SPI_IO_MODE_SEL, sspi->base + SIRFSOC_SPI_RX_DMA_IO_CTRL);
392	regval = (sspi->ctrl_freq / (2 * hz)) - 1;
393
394	if (regval > 0xFFFF || regval < 0) {
395		dev_err(&spi->dev, "Speed %d not supported\n", hz);
396		return -EINVAL;
397	}
398
399	switch (bits_per_word) {
400	case 8:
401		regval |= SIRFSOC_SPI_TRAN_DAT_FORMAT_8;
402		sspi->rx_word = spi_sirfsoc_rx_word_u8;
403		sspi->tx_word = spi_sirfsoc_tx_word_u8;
404		txfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
405					SIRFSOC_SPI_FIFO_WIDTH_BYTE;
406		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
407					SIRFSOC_SPI_FIFO_WIDTH_BYTE;
408		break;
409	case 12:
410	case 16:
411		regval |= (bits_per_word ==  12) ? SIRFSOC_SPI_TRAN_DAT_FORMAT_12 :
412			SIRFSOC_SPI_TRAN_DAT_FORMAT_16;
413		sspi->rx_word = spi_sirfsoc_rx_word_u16;
414		sspi->tx_word = spi_sirfsoc_tx_word_u16;
415		txfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
416					SIRFSOC_SPI_FIFO_WIDTH_WORD;
417		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
418					SIRFSOC_SPI_FIFO_WIDTH_WORD;
419		break;
420	case 32:
421		regval |= SIRFSOC_SPI_TRAN_DAT_FORMAT_32;
422		sspi->rx_word = spi_sirfsoc_rx_word_u32;
423		sspi->tx_word = spi_sirfsoc_tx_word_u32;
424		txfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
425					SIRFSOC_SPI_FIFO_WIDTH_DWORD;
426		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
427					SIRFSOC_SPI_FIFO_WIDTH_DWORD;
428		break;
429	default:
430		dev_err(&spi->dev, "Bits per word %d not supported\n",
431		       bits_per_word);
432		return -EINVAL;
433	}
434
435	if (!(spi->mode & SPI_CS_HIGH))
436		regval |= SIRFSOC_SPI_CS_IDLE_STAT;
437	if (!(spi->mode & SPI_LSB_FIRST))
438		regval |= SIRFSOC_SPI_TRAN_MSB;
439	if (spi->mode & SPI_CPOL)
440		regval |= SIRFSOC_SPI_CLK_IDLE_STAT;
441
442	/*
443	 * Data should be driven at least 1/2 cycle before the fetch edge to make
444	 * sure that data gets stable at the fetch edge.
445	 */
446	if (((spi->mode & SPI_CPOL) && (spi->mode & SPI_CPHA)) ||
447	    (!(spi->mode & SPI_CPOL) && !(spi->mode & SPI_CPHA)))
448		regval &= ~SIRFSOC_SPI_DRV_POS_EDGE;
449	else
450		regval |= SIRFSOC_SPI_DRV_POS_EDGE;
451
452	writel(SIRFSOC_SPI_FIFO_SC(fifo_size - 2) |
453			SIRFSOC_SPI_FIFO_LC(fifo_size / 2) |
454			SIRFSOC_SPI_FIFO_HC(2),
455		sspi->base + SIRFSOC_SPI_TXFIFO_LEVEL_CHK);
456	writel(SIRFSOC_SPI_FIFO_SC(2) |
457			SIRFSOC_SPI_FIFO_LC(fifo_size / 2) |
458			SIRFSOC_SPI_FIFO_HC(fifo_size - 2),
459		sspi->base + SIRFSOC_SPI_RXFIFO_LEVEL_CHK);
460	writel(txfifo_ctrl, sspi->base + SIRFSOC_SPI_TXFIFO_CTRL);
461	writel(rxfifo_ctrl, sspi->base + SIRFSOC_SPI_RXFIFO_CTRL);
462
463	writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
464	return 0;
465}
466
467static int spi_sirfsoc_setup(struct spi_device *spi)
468{
469	struct sirfsoc_spi *sspi;
470
471	if (!spi->max_speed_hz)
472		return -EINVAL;
473
474	sspi = spi_master_get_devdata(spi->master);
475
476	if (!spi->bits_per_word)
477		spi->bits_per_word = 8;
478
479	return spi_sirfsoc_setup_transfer(spi, NULL);
480}
481
482static int __devinit spi_sirfsoc_probe(struct platform_device *pdev)
483{
484	struct sirfsoc_spi *sspi;
485	struct spi_master *master;
486	struct resource *mem_res;
487	int num_cs, cs_gpio, irq;
488	int i;
489	int ret;
490
491	ret = of_property_read_u32(pdev->dev.of_node,
492			"sirf,spi-num-chipselects", &num_cs);
493	if (ret < 0) {
494		dev_err(&pdev->dev, "Unable to get chip select number\n");
495		goto err_cs;
496	}
497
498	master = spi_alloc_master(&pdev->dev, sizeof(*sspi) + sizeof(int) * num_cs);
499	if (!master) {
500		dev_err(&pdev->dev, "Unable to allocate SPI master\n");
501		return -ENOMEM;
502	}
503	platform_set_drvdata(pdev, master);
504	sspi = spi_master_get_devdata(master);
505
506	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
507	if (!mem_res) {
508		dev_err(&pdev->dev, "Unable to get IO resource\n");
509		ret = -ENODEV;
510		goto free_master;
511	}
512	master->num_chipselect = num_cs;
513
514	for (i = 0; i < master->num_chipselect; i++) {
515		cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", i);
516		if (cs_gpio < 0) {
517			dev_err(&pdev->dev, "can't get cs gpio from DT\n");
518			ret = -ENODEV;
519			goto free_master;
520		}
521
522		sspi->chipselect[i] = cs_gpio;
523		if (cs_gpio == 0)
524			continue; /* use cs from spi controller */
525
526		ret = gpio_request(cs_gpio, DRIVER_NAME);
527		if (ret) {
528			while (i > 0) {
529				i--;
530				if (sspi->chipselect[i] > 0)
531					gpio_free(sspi->chipselect[i]);
532			}
533			dev_err(&pdev->dev, "fail to request cs gpios\n");
534			goto free_master;
535		}
536	}
537
538	sspi->base = devm_request_and_ioremap(&pdev->dev, mem_res);
539	if (!sspi->base) {
540		dev_err(&pdev->dev, "IO remap failed!\n");
541		ret = -ENOMEM;
542		goto free_master;
543	}
544
545	irq = platform_get_irq(pdev, 0);
546	if (irq < 0) {
547		ret = -ENXIO;
548		goto free_master;
549	}
550	ret = devm_request_irq(&pdev->dev, irq, spi_sirfsoc_irq, 0,
551				DRIVER_NAME, sspi);
552	if (ret)
553		goto free_master;
554
555	sspi->bitbang.master = spi_master_get(master);
556	sspi->bitbang.chipselect = spi_sirfsoc_chipselect;
557	sspi->bitbang.setup_transfer = spi_sirfsoc_setup_transfer;
558	sspi->bitbang.txrx_bufs = spi_sirfsoc_transfer;
559	sspi->bitbang.master->setup = spi_sirfsoc_setup;
560	master->bus_num = pdev->id;
561	sspi->bitbang.master->dev.of_node = pdev->dev.of_node;
562
563	sspi->p = pinctrl_get_select_default(&pdev->dev);
564	ret = IS_ERR(sspi->p);
565	if (ret)
566		goto free_master;
567
568	sspi->clk = clk_get(&pdev->dev, NULL);
569	if (IS_ERR(sspi->clk)) {
570		ret = -EINVAL;
571		goto free_pin;
572	}
573	clk_enable(sspi->clk);
574	sspi->ctrl_freq = clk_get_rate(sspi->clk);
575
576	init_completion(&sspi->done);
577
578	tasklet_init(&sspi->tasklet_tx, spi_sirfsoc_tasklet_tx,
579		     (unsigned long)sspi);
580
581	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
582	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
583	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
584	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
585	/* We are not using dummy delay between command and data */
586	writel(0, sspi->base + SIRFSOC_SPI_DUMMY_DELAY_CTL);
587
588	ret = spi_bitbang_start(&sspi->bitbang);
589	if (ret)
590		goto free_clk;
591
592	dev_info(&pdev->dev, "registerred, bus number = %d\n", master->bus_num);
593
594	return 0;
595
596free_clk:
597	clk_disable(sspi->clk);
598	clk_put(sspi->clk);
599free_pin:
600	pinctrl_put(sspi->p);
601free_master:
602	spi_master_put(master);
603err_cs:
604	return ret;
605}
606
607static int  __devexit spi_sirfsoc_remove(struct platform_device *pdev)
608{
609	struct spi_master *master;
610	struct sirfsoc_spi *sspi;
611	int i;
612
613	master = platform_get_drvdata(pdev);
614	sspi = spi_master_get_devdata(master);
615
616	spi_bitbang_stop(&sspi->bitbang);
617	for (i = 0; i < master->num_chipselect; i++) {
618		if (sspi->chipselect[i] > 0)
619			gpio_free(sspi->chipselect[i]);
620	}
621	clk_disable(sspi->clk);
622	clk_put(sspi->clk);
623	pinctrl_put(sspi->p);
624	spi_master_put(master);
625	return 0;
626}
627
628#ifdef CONFIG_PM
629static int spi_sirfsoc_suspend(struct device *dev)
630{
631	struct platform_device *pdev = to_platform_device(dev);
632	struct spi_master *master = platform_get_drvdata(pdev);
633	struct sirfsoc_spi *sspi = spi_master_get_devdata(master);
634
635	clk_disable(sspi->clk);
636	return 0;
637}
638
639static int spi_sirfsoc_resume(struct device *dev)
640{
641	struct platform_device *pdev = to_platform_device(dev);
642	struct spi_master *master = platform_get_drvdata(pdev);
643	struct sirfsoc_spi *sspi = spi_master_get_devdata(master);
644
645	clk_enable(sspi->clk);
646	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
647	writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
648	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
649	writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
650
651	return 0;
652}
653
654static const struct dev_pm_ops spi_sirfsoc_pm_ops = {
655	.suspend = spi_sirfsoc_suspend,
656	.resume = spi_sirfsoc_resume,
657};
658#endif
659
660static const struct of_device_id spi_sirfsoc_of_match[] = {
661	{ .compatible = "sirf,prima2-spi", },
662	{}
663};
664MODULE_DEVICE_TABLE(of, sirfsoc_spi_of_match);
665
666static struct platform_driver spi_sirfsoc_driver = {
667	.driver = {
668		.name = DRIVER_NAME,
669		.owner = THIS_MODULE,
670#ifdef CONFIG_PM
671		.pm     = &spi_sirfsoc_pm_ops,
672#endif
673		.of_match_table = spi_sirfsoc_of_match,
674	},
675	.probe = spi_sirfsoc_probe,
676	.remove = __devexit_p(spi_sirfsoc_remove),
677};
678module_platform_driver(spi_sirfsoc_driver);
679
680MODULE_DESCRIPTION("SiRF SoC SPI master driver");
681MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>, "
682		"Barry Song <Baohua.Song@csr.com>");
683MODULE_LICENSE("GPL v2");