V4L/DVB (9682): gspca: New subdriver parameter 'bulk_nurbs'.
[linux-2.6/mini2440.git] / drivers / spi / spi_s3c24xx.c
blobc252cbac00f1d14ef273f53dea2ca7f39edd38b5
1 /* linux/drivers/spi/spi_s3c24xx.c
3 * Copyright (c) 2006 Ben Dooks
4 * Copyright (c) 2006 Simtec Electronics
5 * Ben Dooks <ben@simtec.co.uk>
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.
13 #include <linux/init.h>
14 #include <linux/spinlock.h>
15 #include <linux/workqueue.h>
16 #include <linux/interrupt.h>
17 #include <linux/delay.h>
18 #include <linux/errno.h>
19 #include <linux/err.h>
20 #include <linux/clk.h>
21 #include <linux/platform_device.h>
23 #include <linux/spi/spi.h>
24 #include <linux/spi/spi_bitbang.h>
26 #include <asm/io.h>
27 #include <asm/dma.h>
28 #include <mach/hardware.h>
30 #include <mach/regs-gpio.h>
31 #include <asm/plat-s3c24xx/regs-spi.h>
32 #include <mach/spi.h>
34 struct s3c24xx_spi {
35 /* bitbang has to be first */
36 struct spi_bitbang bitbang;
37 struct completion done;
39 void __iomem *regs;
40 int irq;
41 int len;
42 int count;
44 void (*set_cs)(struct s3c2410_spi_info *spi,
45 int cs, int pol);
47 /* data buffers */
48 const unsigned char *tx;
49 unsigned char *rx;
51 struct clk *clk;
52 struct resource *ioarea;
53 struct spi_master *master;
54 struct spi_device *curdev;
55 struct device *dev;
56 struct s3c2410_spi_info *pdata;
59 #define SPCON_DEFAULT (S3C2410_SPCON_MSTR | S3C2410_SPCON_SMOD_INT)
60 #define SPPIN_DEFAULT (S3C2410_SPPIN_KEEP)
62 static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev)
64 return spi_master_get_devdata(sdev->master);
67 static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol)
69 s3c2410_gpio_setpin(spi->pin_cs, pol);
72 static void s3c24xx_spi_chipsel(struct spi_device *spi, int value)
74 struct s3c24xx_spi *hw = to_hw(spi);
75 unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
76 unsigned int spcon;
78 switch (value) {
79 case BITBANG_CS_INACTIVE:
80 hw->set_cs(hw->pdata, spi->chip_select, cspol^1);
81 break;
83 case BITBANG_CS_ACTIVE:
84 spcon = readb(hw->regs + S3C2410_SPCON);
86 if (spi->mode & SPI_CPHA)
87 spcon |= S3C2410_SPCON_CPHA_FMTB;
88 else
89 spcon &= ~S3C2410_SPCON_CPHA_FMTB;
91 if (spi->mode & SPI_CPOL)
92 spcon |= S3C2410_SPCON_CPOL_HIGH;
93 else
94 spcon &= ~S3C2410_SPCON_CPOL_HIGH;
96 spcon |= S3C2410_SPCON_ENSCK;
98 /* write new configration */
100 writeb(spcon, hw->regs + S3C2410_SPCON);
101 hw->set_cs(hw->pdata, spi->chip_select, cspol);
103 break;
107 static int s3c24xx_spi_setupxfer(struct spi_device *spi,
108 struct spi_transfer *t)
110 struct s3c24xx_spi *hw = to_hw(spi);
111 unsigned int bpw;
112 unsigned int hz;
113 unsigned int div;
115 bpw = t ? t->bits_per_word : spi->bits_per_word;
116 hz = t ? t->speed_hz : spi->max_speed_hz;
118 if (bpw != 8) {
119 dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw);
120 return -EINVAL;
123 div = clk_get_rate(hw->clk) / hz;
125 /* is clk = pclk / (2 * (pre+1)), or is it
126 * clk = (pclk * 2) / ( pre + 1) */
128 div /= 2;
130 if (div > 0)
131 div -= 1;
133 if (div > 255)
134 div = 255;
136 dev_dbg(&spi->dev, "setting pre-scaler to %d (hz %d)\n", div, hz);
137 writeb(div, hw->regs + S3C2410_SPPRE);
139 spin_lock(&hw->bitbang.lock);
140 if (!hw->bitbang.busy) {
141 hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
142 /* need to ndelay for 0.5 clocktick ? */
144 spin_unlock(&hw->bitbang.lock);
146 return 0;
149 /* the spi->mode bits understood by this driver: */
150 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
152 static int s3c24xx_spi_setup(struct spi_device *spi)
154 int ret;
156 if (!spi->bits_per_word)
157 spi->bits_per_word = 8;
159 if (spi->mode & ~MODEBITS) {
160 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
161 spi->mode & ~MODEBITS);
162 return -EINVAL;
165 ret = s3c24xx_spi_setupxfer(spi, NULL);
166 if (ret < 0) {
167 dev_err(&spi->dev, "setupxfer returned %d\n", ret);
168 return ret;
171 dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n",
172 __func__, spi->mode, spi->bits_per_word,
173 spi->max_speed_hz);
175 return 0;
178 static inline unsigned int hw_txbyte(struct s3c24xx_spi *hw, int count)
180 return hw->tx ? hw->tx[count] : 0;
183 static int s3c24xx_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
185 struct s3c24xx_spi *hw = to_hw(spi);
187 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
188 t->tx_buf, t->rx_buf, t->len);
190 hw->tx = t->tx_buf;
191 hw->rx = t->rx_buf;
192 hw->len = t->len;
193 hw->count = 0;
195 init_completion(&hw->done);
197 /* send the first byte */
198 writeb(hw_txbyte(hw, 0), hw->regs + S3C2410_SPTDAT);
200 wait_for_completion(&hw->done);
202 return hw->count;
205 static irqreturn_t s3c24xx_spi_irq(int irq, void *dev)
207 struct s3c24xx_spi *hw = dev;
208 unsigned int spsta = readb(hw->regs + S3C2410_SPSTA);
209 unsigned int count = hw->count;
211 if (spsta & S3C2410_SPSTA_DCOL) {
212 dev_dbg(hw->dev, "data-collision\n");
213 complete(&hw->done);
214 goto irq_done;
217 if (!(spsta & S3C2410_SPSTA_READY)) {
218 dev_dbg(hw->dev, "spi not ready for tx?\n");
219 complete(&hw->done);
220 goto irq_done;
223 hw->count++;
225 if (hw->rx)
226 hw->rx[count] = readb(hw->regs + S3C2410_SPRDAT);
228 count++;
230 if (count < hw->len)
231 writeb(hw_txbyte(hw, count), hw->regs + S3C2410_SPTDAT);
232 else
233 complete(&hw->done);
235 irq_done:
236 return IRQ_HANDLED;
239 static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw)
241 /* for the moment, permanently enable the clock */
243 clk_enable(hw->clk);
245 /* program defaults into the registers */
247 writeb(0xff, hw->regs + S3C2410_SPPRE);
248 writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN);
249 writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON);
251 if (hw->pdata && hw->pdata->gpio_setup)
252 hw->pdata->gpio_setup(hw->pdata, 1);
255 static int __init s3c24xx_spi_probe(struct platform_device *pdev)
257 struct s3c2410_spi_info *pdata;
258 struct s3c24xx_spi *hw;
259 struct spi_master *master;
260 struct resource *res;
261 int err = 0;
263 master = spi_alloc_master(&pdev->dev, sizeof(struct s3c24xx_spi));
264 if (master == NULL) {
265 dev_err(&pdev->dev, "No memory for spi_master\n");
266 err = -ENOMEM;
267 goto err_nomem;
270 hw = spi_master_get_devdata(master);
271 memset(hw, 0, sizeof(struct s3c24xx_spi));
273 hw->master = spi_master_get(master);
274 hw->pdata = pdata = pdev->dev.platform_data;
275 hw->dev = &pdev->dev;
277 if (pdata == NULL) {
278 dev_err(&pdev->dev, "No platform data supplied\n");
279 err = -ENOENT;
280 goto err_no_pdata;
283 platform_set_drvdata(pdev, hw);
284 init_completion(&hw->done);
286 /* setup the master state. */
288 master->num_chipselect = hw->pdata->num_cs;
289 master->bus_num = pdata->bus_num;
291 /* setup the state for the bitbang driver */
293 hw->bitbang.master = hw->master;
294 hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer;
295 hw->bitbang.chipselect = s3c24xx_spi_chipsel;
296 hw->bitbang.txrx_bufs = s3c24xx_spi_txrx;
297 hw->bitbang.master->setup = s3c24xx_spi_setup;
299 dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);
301 /* find and map our resources */
303 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
304 if (res == NULL) {
305 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
306 err = -ENOENT;
307 goto err_no_iores;
310 hw->ioarea = request_mem_region(res->start, (res->end - res->start)+1,
311 pdev->name);
313 if (hw->ioarea == NULL) {
314 dev_err(&pdev->dev, "Cannot reserve region\n");
315 err = -ENXIO;
316 goto err_no_iores;
319 hw->regs = ioremap(res->start, (res->end - res->start)+1);
320 if (hw->regs == NULL) {
321 dev_err(&pdev->dev, "Cannot map IO\n");
322 err = -ENXIO;
323 goto err_no_iomap;
326 hw->irq = platform_get_irq(pdev, 0);
327 if (hw->irq < 0) {
328 dev_err(&pdev->dev, "No IRQ specified\n");
329 err = -ENOENT;
330 goto err_no_irq;
333 err = request_irq(hw->irq, s3c24xx_spi_irq, 0, pdev->name, hw);
334 if (err) {
335 dev_err(&pdev->dev, "Cannot claim IRQ\n");
336 goto err_no_irq;
339 hw->clk = clk_get(&pdev->dev, "spi");
340 if (IS_ERR(hw->clk)) {
341 dev_err(&pdev->dev, "No clock for device\n");
342 err = PTR_ERR(hw->clk);
343 goto err_no_clk;
346 s3c24xx_spi_initialsetup(hw);
348 /* setup any gpio we can */
350 if (!pdata->set_cs) {
351 hw->set_cs = s3c24xx_spi_gpiocs;
353 s3c2410_gpio_setpin(pdata->pin_cs, 1);
354 s3c2410_gpio_cfgpin(pdata->pin_cs, S3C2410_GPIO_OUTPUT);
355 } else
356 hw->set_cs = pdata->set_cs;
358 /* register our spi controller */
360 err = spi_bitbang_start(&hw->bitbang);
361 if (err) {
362 dev_err(&pdev->dev, "Failed to register SPI master\n");
363 goto err_register;
366 return 0;
368 err_register:
369 clk_disable(hw->clk);
370 clk_put(hw->clk);
372 err_no_clk:
373 free_irq(hw->irq, hw);
375 err_no_irq:
376 iounmap(hw->regs);
378 err_no_iomap:
379 release_resource(hw->ioarea);
380 kfree(hw->ioarea);
382 err_no_iores:
383 err_no_pdata:
384 spi_master_put(hw->master);;
386 err_nomem:
387 return err;
390 static int __exit s3c24xx_spi_remove(struct platform_device *dev)
392 struct s3c24xx_spi *hw = platform_get_drvdata(dev);
394 platform_set_drvdata(dev, NULL);
396 spi_unregister_master(hw->master);
398 clk_disable(hw->clk);
399 clk_put(hw->clk);
401 free_irq(hw->irq, hw);
402 iounmap(hw->regs);
404 release_resource(hw->ioarea);
405 kfree(hw->ioarea);
407 spi_master_put(hw->master);
408 return 0;
412 #ifdef CONFIG_PM
414 static int s3c24xx_spi_suspend(struct platform_device *pdev, pm_message_t msg)
416 struct s3c24xx_spi *hw = platform_get_drvdata(pdev);
418 if (hw->pdata && hw->pdata->gpio_setup)
419 hw->pdata->gpio_setup(hw->pdata, 0);
421 clk_disable(hw->clk);
422 return 0;
425 static int s3c24xx_spi_resume(struct platform_device *pdev)
427 struct s3c24xx_spi *hw = platform_get_drvdata(pdev);
429 s3c24xx_spi_initialsetup(hw);
430 return 0;
433 #else
434 #define s3c24xx_spi_suspend NULL
435 #define s3c24xx_spi_resume NULL
436 #endif
438 MODULE_ALIAS("platform:s3c2410-spi");
439 static struct platform_driver s3c24xx_spi_driver = {
440 .remove = __exit_p(s3c24xx_spi_remove),
441 .suspend = s3c24xx_spi_suspend,
442 .resume = s3c24xx_spi_resume,
443 .driver = {
444 .name = "s3c2410-spi",
445 .owner = THIS_MODULE,
449 static int __init s3c24xx_spi_init(void)
451 return platform_driver_probe(&s3c24xx_spi_driver, s3c24xx_spi_probe);
454 static void __exit s3c24xx_spi_exit(void)
456 platform_driver_unregister(&s3c24xx_spi_driver);
459 module_init(s3c24xx_spi_init);
460 module_exit(s3c24xx_spi_exit);
462 MODULE_DESCRIPTION("S3C24XX SPI Driver");
463 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
464 MODULE_LICENSE("GPL");