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11#include <linux/module.h>
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>
24#include <linux/slab.h>
25
26#include <linux/spi/spi.h>
27#include <linux/spi/spi_bitbang.h>
28
29#include <linux/platform_data/spi-nuc900.h>
30
31
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
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
50struct 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
69static inline struct nuc900_spi *to_hw(struct spi_device *sdev)
70{
71 return spi_master_get_devdata(sdev->master);
72}
73
74static 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
110static 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
123static 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
144static 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
161static 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
177static int nuc900_spi_setupxfer(struct spi_device *spi,
178 struct spi_transfer *t)
179{
180 return 0;
181}
182
183static int nuc900_spi_setup(struct spi_device *spi)
184{
185 return 0;
186}
187
188static inline unsigned int hw_txbyte(struct nuc900_spi *hw, int count)
189{
190 return hw->tx ? hw->tx[count] : 0;
191}
192
193static 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
211static 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
241static 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
259static 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
277static 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
295static 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
313static 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
329static void nuc900_set_divider(struct nuc900_spi *hw)
330{
331 __raw_writel(hw->pdata->divider, hw->regs + USI_DIV);
332}
333
334static 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
349static 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 hw->master = spi_master_get(master);
364 hw->pdata = pdev->dev.platform_data;
365 hw->dev = &pdev->dev;
366
367 if (hw->pdata == NULL) {
368 dev_err(&pdev->dev, "No platform data supplied\n");
369 err = -ENOENT;
370 goto err_pdata;
371 }
372
373 platform_set_drvdata(pdev, hw);
374 init_completion(&hw->done);
375
376 master->mode_bits = SPI_MODE_0;
377 master->num_chipselect = hw->pdata->num_cs;
378 master->bus_num = hw->pdata->bus_num;
379 hw->bitbang.master = hw->master;
380 hw->bitbang.setup_transfer = nuc900_spi_setupxfer;
381 hw->bitbang.chipselect = nuc900_spi_chipsel;
382 hw->bitbang.txrx_bufs = nuc900_spi_txrx;
383 hw->bitbang.master->setup = nuc900_spi_setup;
384
385 hw->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
386 if (hw->res == NULL) {
387 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
388 err = -ENOENT;
389 goto err_pdata;
390 }
391
392 hw->ioarea = request_mem_region(hw->res->start,
393 resource_size(hw->res), pdev->name);
394
395 if (hw->ioarea == NULL) {
396 dev_err(&pdev->dev, "Cannot reserve region\n");
397 err = -ENXIO;
398 goto err_pdata;
399 }
400
401 hw->regs = ioremap(hw->res->start, resource_size(hw->res));
402 if (hw->regs == NULL) {
403 dev_err(&pdev->dev, "Cannot map IO\n");
404 err = -ENXIO;
405 goto err_iomap;
406 }
407
408 hw->irq = platform_get_irq(pdev, 0);
409 if (hw->irq < 0) {
410 dev_err(&pdev->dev, "No IRQ specified\n");
411 err = -ENOENT;
412 goto err_irq;
413 }
414
415 err = request_irq(hw->irq, nuc900_spi_irq, 0, pdev->name, hw);
416 if (err) {
417 dev_err(&pdev->dev, "Cannot claim IRQ\n");
418 goto err_irq;
419 }
420
421 hw->clk = clk_get(&pdev->dev, "spi");
422 if (IS_ERR(hw->clk)) {
423 dev_err(&pdev->dev, "No clock for device\n");
424 err = PTR_ERR(hw->clk);
425 goto err_clk;
426 }
427
428 mfp_set_groupg(&pdev->dev, NULL);
429 nuc900_init_spi(hw);
430
431 err = spi_bitbang_start(&hw->bitbang);
432 if (err) {
433 dev_err(&pdev->dev, "Failed to register SPI master\n");
434 goto err_register;
435 }
436
437 return 0;
438
439err_register:
440 clk_disable(hw->clk);
441 clk_put(hw->clk);
442err_clk:
443 free_irq(hw->irq, hw);
444err_irq:
445 iounmap(hw->regs);
446err_iomap:
447 release_mem_region(hw->res->start, resource_size(hw->res));
448 kfree(hw->ioarea);
449err_pdata:
450 spi_master_put(hw->master);
451
452err_nomem:
453 return err;
454}
455
456static int __devexit nuc900_spi_remove(struct platform_device *dev)
457{
458 struct nuc900_spi *hw = platform_get_drvdata(dev);
459
460 free_irq(hw->irq, hw);
461
462 platform_set_drvdata(dev, NULL);
463
464 spi_bitbang_stop(&hw->bitbang);
465
466 clk_disable(hw->clk);
467 clk_put(hw->clk);
468
469 iounmap(hw->regs);
470
471 release_mem_region(hw->res->start, resource_size(hw->res));
472 kfree(hw->ioarea);
473
474 spi_master_put(hw->master);
475 return 0;
476}
477
478static struct platform_driver nuc900_spi_driver = {
479 .probe = nuc900_spi_probe,
480 .remove = __devexit_p(nuc900_spi_remove),
481 .driver = {
482 .name = "nuc900-spi",
483 .owner = THIS_MODULE,
484 },
485};
486module_platform_driver(nuc900_spi_driver);
487
488MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
489MODULE_DESCRIPTION("nuc900 spi driver!");
490MODULE_LICENSE("GPL");
491MODULE_ALIAS("platform:nuc900-spi");
492
