Commit | Line | Data |
---|---|---|
30eaed05 WZ |
1 | /* linux/drivers/spi/spi_nuc900.c |
2 | * | |
3 | * Copyright (c) 2009 Nuvoton technology. | |
4 | * Wan ZongShun <mcuos.com@gmail.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/init.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/workqueue.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/errno.h> | |
18 | #include <linux/err.h> | |
19 | #include <linux/clk.h> | |
20 | #include <linux/device.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/gpio.h> | |
23 | #include <linux/io.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
30eaed05 WZ |
25 | |
26 | #include <linux/spi/spi.h> | |
27 | #include <linux/spi/spi_bitbang.h> | |
28 | ||
29 | #include <mach/nuc900_spi.h> | |
30 | ||
31 | /* usi registers offset */ | |
32 | #define USI_CNT 0x00 | |
33 | #define USI_DIV 0x04 | |
34 | #define USI_SSR 0x08 | |
35 | #define USI_RX0 0x10 | |
36 | #define USI_TX0 0x10 | |
37 | ||
38 | /* usi register bit */ | |
39 | #define ENINT (0x01 << 17) | |
40 | #define ENFLG (0x01 << 16) | |
41 | #define TXNUM (0x03 << 8) | |
42 | #define TXNEG (0x01 << 2) | |
43 | #define RXNEG (0x01 << 1) | |
44 | #define LSB (0x01 << 10) | |
45 | #define SELECTLEV (0x01 << 2) | |
46 | #define SELECTPOL (0x01 << 31) | |
47 | #define SELECTSLAVE 0x01 | |
48 | #define GOBUSY 0x01 | |
49 | ||
50 | struct nuc900_spi { | |
51 | struct spi_bitbang bitbang; | |
52 | struct completion done; | |
53 | void __iomem *regs; | |
54 | int irq; | |
55 | int len; | |
56 | int count; | |
57 | const unsigned char *tx; | |
58 | unsigned char *rx; | |
59 | struct clk *clk; | |
60 | struct resource *ioarea; | |
61 | struct spi_master *master; | |
62 | struct spi_device *curdev; | |
63 | struct device *dev; | |
64 | struct nuc900_spi_info *pdata; | |
65 | spinlock_t lock; | |
66 | struct resource *res; | |
67 | }; | |
68 | ||
69 | static inline struct nuc900_spi *to_hw(struct spi_device *sdev) | |
70 | { | |
71 | return spi_master_get_devdata(sdev->master); | |
72 | } | |
73 | ||
74 | static void nuc900_slave_select(struct spi_device *spi, unsigned int ssr) | |
75 | { | |
76 | struct nuc900_spi *hw = to_hw(spi); | |
77 | unsigned int val; | |
78 | unsigned int cs = spi->mode & SPI_CS_HIGH ? 1 : 0; | |
79 | unsigned int cpol = spi->mode & SPI_CPOL ? 1 : 0; | |
80 | unsigned long flags; | |
81 | ||
82 | spin_lock_irqsave(&hw->lock, flags); | |
83 | ||
84 | val = __raw_readl(hw->regs + USI_SSR); | |
85 | ||
86 | if (!cs) | |
87 | val &= ~SELECTLEV; | |
88 | else | |
89 | val |= SELECTLEV; | |
90 | ||
91 | if (!ssr) | |
92 | val &= ~SELECTSLAVE; | |
93 | else | |
94 | val |= SELECTSLAVE; | |
95 | ||
96 | __raw_writel(val, hw->regs + USI_SSR); | |
97 | ||
98 | val = __raw_readl(hw->regs + USI_CNT); | |
99 | ||
100 | if (!cpol) | |
101 | val &= ~SELECTPOL; | |
102 | else | |
103 | val |= SELECTPOL; | |
104 | ||
105 | __raw_writel(val, hw->regs + USI_CNT); | |
106 | ||
107 | spin_unlock_irqrestore(&hw->lock, flags); | |
108 | } | |
109 | ||
110 | static void nuc900_spi_chipsel(struct spi_device *spi, int value) | |
111 | { | |
112 | switch (value) { | |
113 | case BITBANG_CS_INACTIVE: | |
114 | nuc900_slave_select(spi, 0); | |
115 | break; | |
116 | ||
117 | case BITBANG_CS_ACTIVE: | |
118 | nuc900_slave_select(spi, 1); | |
119 | break; | |
120 | } | |
121 | } | |
122 | ||
123 | static void nuc900_spi_setup_txnum(struct nuc900_spi *hw, | |
124 | unsigned int txnum) | |
125 | { | |
126 | unsigned int val; | |
127 | unsigned long flags; | |
128 | ||
129 | spin_lock_irqsave(&hw->lock, flags); | |
130 | ||
131 | val = __raw_readl(hw->regs + USI_CNT); | |
132 | ||
133 | if (!txnum) | |
134 | val &= ~TXNUM; | |
135 | else | |
136 | val |= txnum << 0x08; | |
137 | ||
138 | __raw_writel(val, hw->regs + USI_CNT); | |
139 | ||
140 | spin_unlock_irqrestore(&hw->lock, flags); | |
141 | ||
142 | } | |
143 | ||
144 | static void nuc900_spi_setup_txbitlen(struct nuc900_spi *hw, | |
145 | unsigned int txbitlen) | |
146 | { | |
147 | unsigned int val; | |
148 | unsigned long flags; | |
149 | ||
150 | spin_lock_irqsave(&hw->lock, flags); | |
151 | ||
152 | val = __raw_readl(hw->regs + USI_CNT); | |
153 | ||
154 | val |= (txbitlen << 0x03); | |
155 | ||
156 | __raw_writel(val, hw->regs + USI_CNT); | |
157 | ||
158 | spin_unlock_irqrestore(&hw->lock, flags); | |
159 | } | |
160 | ||
161 | static void nuc900_spi_gobusy(struct nuc900_spi *hw) | |
162 | { | |
163 | unsigned int val; | |
164 | unsigned long flags; | |
165 | ||
166 | spin_lock_irqsave(&hw->lock, flags); | |
167 | ||
168 | val = __raw_readl(hw->regs + USI_CNT); | |
169 | ||
170 | val |= GOBUSY; | |
171 | ||
172 | __raw_writel(val, hw->regs + USI_CNT); | |
173 | ||
174 | spin_unlock_irqrestore(&hw->lock, flags); | |
175 | } | |
176 | ||
177 | static int nuc900_spi_setupxfer(struct spi_device *spi, | |
178 | struct spi_transfer *t) | |
179 | { | |
180 | return 0; | |
181 | } | |
182 | ||
183 | static int nuc900_spi_setup(struct spi_device *spi) | |
184 | { | |
185 | return 0; | |
186 | } | |
187 | ||
188 | static inline unsigned int hw_txbyte(struct nuc900_spi *hw, int count) | |
189 | { | |
190 | return hw->tx ? hw->tx[count] : 0; | |
191 | } | |
192 | ||
193 | static int nuc900_spi_txrx(struct spi_device *spi, struct spi_transfer *t) | |
194 | { | |
195 | struct nuc900_spi *hw = to_hw(spi); | |
196 | ||
197 | hw->tx = t->tx_buf; | |
198 | hw->rx = t->rx_buf; | |
199 | hw->len = t->len; | |
200 | hw->count = 0; | |
201 | ||
202 | __raw_writel(hw_txbyte(hw, 0x0), hw->regs + USI_TX0); | |
203 | ||
204 | nuc900_spi_gobusy(hw); | |
205 | ||
206 | wait_for_completion(&hw->done); | |
207 | ||
208 | return hw->count; | |
209 | } | |
210 | ||
211 | static irqreturn_t nuc900_spi_irq(int irq, void *dev) | |
212 | { | |
213 | struct nuc900_spi *hw = dev; | |
214 | unsigned int status; | |
215 | unsigned int count = hw->count; | |
216 | ||
217 | status = __raw_readl(hw->regs + USI_CNT); | |
218 | __raw_writel(status, hw->regs + USI_CNT); | |
219 | ||
220 | if (status & ENFLG) { | |
221 | hw->count++; | |
222 | ||
223 | if (hw->rx) | |
224 | hw->rx[count] = __raw_readl(hw->regs + USI_RX0); | |
225 | count++; | |
226 | ||
227 | if (count < hw->len) { | |
228 | __raw_writel(hw_txbyte(hw, count), hw->regs + USI_TX0); | |
229 | nuc900_spi_gobusy(hw); | |
230 | } else { | |
231 | complete(&hw->done); | |
232 | } | |
233 | ||
234 | return IRQ_HANDLED; | |
235 | } | |
236 | ||
237 | complete(&hw->done); | |
238 | return IRQ_HANDLED; | |
239 | } | |
240 | ||
241 | static void nuc900_tx_edge(struct nuc900_spi *hw, unsigned int edge) | |
242 | { | |
243 | unsigned int val; | |
244 | unsigned long flags; | |
245 | ||
246 | spin_lock_irqsave(&hw->lock, flags); | |
247 | ||
248 | val = __raw_readl(hw->regs + USI_CNT); | |
249 | ||
250 | if (edge) | |
251 | val |= TXNEG; | |
252 | else | |
253 | val &= ~TXNEG; | |
254 | __raw_writel(val, hw->regs + USI_CNT); | |
255 | ||
256 | spin_unlock_irqrestore(&hw->lock, flags); | |
257 | } | |
258 | ||
259 | static void nuc900_rx_edge(struct nuc900_spi *hw, unsigned int edge) | |
260 | { | |
261 | unsigned int val; | |
262 | unsigned long flags; | |
263 | ||
264 | spin_lock_irqsave(&hw->lock, flags); | |
265 | ||
266 | val = __raw_readl(hw->regs + USI_CNT); | |
267 | ||
268 | if (edge) | |
269 | val |= RXNEG; | |
270 | else | |
271 | val &= ~RXNEG; | |
272 | __raw_writel(val, hw->regs + USI_CNT); | |
273 | ||
274 | spin_unlock_irqrestore(&hw->lock, flags); | |
275 | } | |
276 | ||
277 | static void nuc900_send_first(struct nuc900_spi *hw, unsigned int lsb) | |
278 | { | |
279 | unsigned int val; | |
280 | unsigned long flags; | |
281 | ||
282 | spin_lock_irqsave(&hw->lock, flags); | |
283 | ||
284 | val = __raw_readl(hw->regs + USI_CNT); | |
285 | ||
286 | if (lsb) | |
287 | val |= LSB; | |
288 | else | |
289 | val &= ~LSB; | |
290 | __raw_writel(val, hw->regs + USI_CNT); | |
291 | ||
292 | spin_unlock_irqrestore(&hw->lock, flags); | |
293 | } | |
294 | ||
295 | static void nuc900_set_sleep(struct nuc900_spi *hw, unsigned int sleep) | |
296 | { | |
297 | unsigned int val; | |
298 | unsigned long flags; | |
299 | ||
300 | spin_lock_irqsave(&hw->lock, flags); | |
301 | ||
302 | val = __raw_readl(hw->regs + USI_CNT); | |
303 | ||
304 | if (sleep) | |
305 | val |= (sleep << 12); | |
306 | else | |
307 | val &= ~(0x0f << 12); | |
308 | __raw_writel(val, hw->regs + USI_CNT); | |
309 | ||
310 | spin_unlock_irqrestore(&hw->lock, flags); | |
311 | } | |
312 | ||
313 | static void nuc900_enable_int(struct nuc900_spi *hw) | |
314 | { | |
315 | unsigned int val; | |
316 | unsigned long flags; | |
317 | ||
318 | spin_lock_irqsave(&hw->lock, flags); | |
319 | ||
320 | val = __raw_readl(hw->regs + USI_CNT); | |
321 | ||
322 | val |= ENINT; | |
323 | ||
324 | __raw_writel(val, hw->regs + USI_CNT); | |
325 | ||
326 | spin_unlock_irqrestore(&hw->lock, flags); | |
327 | } | |
328 | ||
329 | static void nuc900_set_divider(struct nuc900_spi *hw) | |
330 | { | |
331 | __raw_writel(hw->pdata->divider, hw->regs + USI_DIV); | |
332 | } | |
333 | ||
334 | static void nuc900_init_spi(struct nuc900_spi *hw) | |
335 | { | |
336 | clk_enable(hw->clk); | |
337 | spin_lock_init(&hw->lock); | |
338 | ||
339 | nuc900_tx_edge(hw, hw->pdata->txneg); | |
340 | nuc900_rx_edge(hw, hw->pdata->rxneg); | |
341 | nuc900_send_first(hw, hw->pdata->lsb); | |
342 | nuc900_set_sleep(hw, hw->pdata->sleep); | |
343 | nuc900_spi_setup_txbitlen(hw, hw->pdata->txbitlen); | |
344 | nuc900_spi_setup_txnum(hw, hw->pdata->txnum); | |
345 | nuc900_set_divider(hw); | |
346 | nuc900_enable_int(hw); | |
347 | } | |
348 | ||
349 | static int __devinit nuc900_spi_probe(struct platform_device *pdev) | |
350 | { | |
351 | struct nuc900_spi *hw; | |
352 | struct spi_master *master; | |
353 | int err = 0; | |
354 | ||
355 | master = spi_alloc_master(&pdev->dev, sizeof(struct nuc900_spi)); | |
356 | if (master == NULL) { | |
357 | dev_err(&pdev->dev, "No memory for spi_master\n"); | |
358 | err = -ENOMEM; | |
359 | goto err_nomem; | |
360 | } | |
361 | ||
362 | hw = spi_master_get_devdata(master); | |
363 | memset(hw, 0, sizeof(struct nuc900_spi)); | |
364 | ||
365 | hw->master = spi_master_get(master); | |
366 | hw->pdata = pdev->dev.platform_data; | |
367 | hw->dev = &pdev->dev; | |
368 | ||
369 | if (hw->pdata == NULL) { | |
370 | dev_err(&pdev->dev, "No platform data supplied\n"); | |
371 | err = -ENOENT; | |
372 | goto err_pdata; | |
373 | } | |
374 | ||
375 | platform_set_drvdata(pdev, hw); | |
376 | init_completion(&hw->done); | |
377 | ||
378 | master->mode_bits = SPI_MODE_0; | |
379 | master->num_chipselect = hw->pdata->num_cs; | |
380 | master->bus_num = hw->pdata->bus_num; | |
381 | hw->bitbang.master = hw->master; | |
382 | hw->bitbang.setup_transfer = nuc900_spi_setupxfer; | |
383 | hw->bitbang.chipselect = nuc900_spi_chipsel; | |
384 | hw->bitbang.txrx_bufs = nuc900_spi_txrx; | |
385 | hw->bitbang.master->setup = nuc900_spi_setup; | |
386 | ||
387 | hw->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
388 | if (hw->res == NULL) { | |
389 | dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); | |
390 | err = -ENOENT; | |
391 | goto err_pdata; | |
392 | } | |
393 | ||
394 | hw->ioarea = request_mem_region(hw->res->start, | |
395 | resource_size(hw->res), pdev->name); | |
396 | ||
397 | if (hw->ioarea == NULL) { | |
398 | dev_err(&pdev->dev, "Cannot reserve region\n"); | |
399 | err = -ENXIO; | |
400 | goto err_pdata; | |
401 | } | |
402 | ||
403 | hw->regs = ioremap(hw->res->start, resource_size(hw->res)); | |
404 | if (hw->regs == NULL) { | |
405 | dev_err(&pdev->dev, "Cannot map IO\n"); | |
406 | err = -ENXIO; | |
407 | goto err_iomap; | |
408 | } | |
409 | ||
410 | hw->irq = platform_get_irq(pdev, 0); | |
411 | if (hw->irq < 0) { | |
412 | dev_err(&pdev->dev, "No IRQ specified\n"); | |
413 | err = -ENOENT; | |
414 | goto err_irq; | |
415 | } | |
416 | ||
417 | err = request_irq(hw->irq, nuc900_spi_irq, 0, pdev->name, hw); | |
418 | if (err) { | |
419 | dev_err(&pdev->dev, "Cannot claim IRQ\n"); | |
420 | goto err_irq; | |
421 | } | |
422 | ||
423 | hw->clk = clk_get(&pdev->dev, "spi"); | |
424 | if (IS_ERR(hw->clk)) { | |
425 | dev_err(&pdev->dev, "No clock for device\n"); | |
426 | err = PTR_ERR(hw->clk); | |
427 | goto err_clk; | |
428 | } | |
429 | ||
430 | mfp_set_groupg(&pdev->dev); | |
431 | nuc900_init_spi(hw); | |
432 | ||
433 | err = spi_bitbang_start(&hw->bitbang); | |
434 | if (err) { | |
435 | dev_err(&pdev->dev, "Failed to register SPI master\n"); | |
436 | goto err_register; | |
437 | } | |
438 | ||
439 | return 0; | |
440 | ||
441 | err_register: | |
442 | clk_disable(hw->clk); | |
443 | clk_put(hw->clk); | |
444 | err_clk: | |
445 | free_irq(hw->irq, hw); | |
446 | err_irq: | |
447 | iounmap(hw->regs); | |
448 | err_iomap: | |
449 | release_mem_region(hw->res->start, resource_size(hw->res)); | |
450 | kfree(hw->ioarea); | |
451 | err_pdata: | |
bc3f67a3 | 452 | spi_master_put(hw->master); |
30eaed05 WZ |
453 | |
454 | err_nomem: | |
455 | return err; | |
456 | } | |
457 | ||
458 | static int __devexit nuc900_spi_remove(struct platform_device *dev) | |
459 | { | |
460 | struct nuc900_spi *hw = platform_get_drvdata(dev); | |
461 | ||
462 | free_irq(hw->irq, hw); | |
463 | ||
464 | platform_set_drvdata(dev, NULL); | |
465 | ||
708a7e43 | 466 | spi_bitbang_stop(&hw->bitbang); |
30eaed05 WZ |
467 | |
468 | clk_disable(hw->clk); | |
469 | clk_put(hw->clk); | |
470 | ||
471 | iounmap(hw->regs); | |
472 | ||
473 | release_mem_region(hw->res->start, resource_size(hw->res)); | |
474 | kfree(hw->ioarea); | |
475 | ||
476 | spi_master_put(hw->master); | |
477 | return 0; | |
478 | } | |
479 | ||
480 | static struct platform_driver nuc900_spi_driver = { | |
481 | .probe = nuc900_spi_probe, | |
482 | .remove = __devexit_p(nuc900_spi_remove), | |
483 | .driver = { | |
484 | .name = "nuc900-spi", | |
485 | .owner = THIS_MODULE, | |
486 | }, | |
487 | }; | |
488 | ||
489 | static int __init nuc900_spi_init(void) | |
490 | { | |
491 | return platform_driver_register(&nuc900_spi_driver); | |
492 | } | |
493 | ||
494 | static void __exit nuc900_spi_exit(void) | |
495 | { | |
496 | platform_driver_unregister(&nuc900_spi_driver); | |
497 | } | |
498 | ||
499 | module_init(nuc900_spi_init); | |
500 | module_exit(nuc900_spi_exit); | |
501 | ||
502 | MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>"); | |
503 | MODULE_DESCRIPTION("nuc900 spi driver!"); | |
504 | MODULE_LICENSE("GPL"); | |
505 | MODULE_ALIAS("platform:nuc900-spi"); |