Merge commit 'v2.6.27-rc1' into x86/urgent
[linux-2.6] / drivers / spi / mpc52xx_psc_spi.c
1 /*
2  * MPC52xx PSC in SPI mode driver.
3  *
4  * Maintainer: Dragos Carp
5  *
6  * Copyright (C) 2006 TOPTICA Photonics AG.
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/errno.h>
17 #include <linux/interrupt.h>
18
19 #if defined(CONFIG_PPC_MERGE)
20 #include <linux/of_platform.h>
21 #else
22 #include <linux/platform_device.h>
23 #endif
24
25 #include <linux/workqueue.h>
26 #include <linux/completion.h>
27 #include <linux/io.h>
28 #include <linux/delay.h>
29 #include <linux/spi/spi.h>
30 #include <linux/fsl_devices.h>
31
32 #include <asm/mpc52xx.h>
33 #include <asm/mpc52xx_psc.h>
34
35 #define MCLK 20000000 /* PSC port MClk in hz */
36
37 struct mpc52xx_psc_spi {
38         /* fsl_spi_platform data */
39         void (*activate_cs)(u8, u8);
40         void (*deactivate_cs)(u8, u8);
41         u32 sysclk;
42
43         /* driver internal data */
44         struct mpc52xx_psc __iomem *psc;
45         struct mpc52xx_psc_fifo __iomem *fifo;
46         unsigned int irq;
47         u8 bits_per_word;
48         u8 busy;
49
50         struct workqueue_struct *workqueue;
51         struct work_struct work;
52
53         struct list_head queue;
54         spinlock_t lock;
55
56         struct completion done;
57 };
58
59 /* controller state */
60 struct mpc52xx_psc_spi_cs {
61         int bits_per_word;
62         int speed_hz;
63 };
64
65 /* set clock freq, clock ramp, bits per work
66  * if t is NULL then reset the values to the default values
67  */
68 static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
69                 struct spi_transfer *t)
70 {
71         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
72
73         cs->speed_hz = (t && t->speed_hz)
74                         ? t->speed_hz : spi->max_speed_hz;
75         cs->bits_per_word = (t && t->bits_per_word)
76                         ? t->bits_per_word : spi->bits_per_word;
77         cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
78         return 0;
79 }
80
81 static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
82 {
83         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
84         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
85         struct mpc52xx_psc __iomem *psc = mps->psc;
86         u32 sicr;
87         u16 ccr;
88
89         sicr = in_be32(&psc->sicr);
90
91         /* Set clock phase and polarity */
92         if (spi->mode & SPI_CPHA)
93                 sicr |= 0x00001000;
94         else
95                 sicr &= ~0x00001000;
96         if (spi->mode & SPI_CPOL)
97                 sicr |= 0x00002000;
98         else
99                 sicr &= ~0x00002000;
100
101         if (spi->mode & SPI_LSB_FIRST)
102                 sicr |= 0x10000000;
103         else
104                 sicr &= ~0x10000000;
105         out_be32(&psc->sicr, sicr);
106
107         /* Set clock frequency and bits per word
108          * Because psc->ccr is defined as 16bit register instead of 32bit
109          * just set the lower byte of BitClkDiv
110          */
111         ccr = in_be16(&psc->ccr);
112         ccr &= 0xFF00;
113         if (cs->speed_hz)
114                 ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
115         else /* by default SPI Clk 1MHz */
116                 ccr |= (MCLK / 1000000 - 1) & 0xFF;
117         out_be16(&psc->ccr, ccr);
118         mps->bits_per_word = cs->bits_per_word;
119
120         if (mps->activate_cs)
121                 mps->activate_cs(spi->chip_select,
122                                 (spi->mode & SPI_CS_HIGH) ? 1 : 0);
123 }
124
125 static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
126 {
127         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
128
129         if (mps->deactivate_cs)
130                 mps->deactivate_cs(spi->chip_select,
131                                 (spi->mode & SPI_CS_HIGH) ? 1 : 0);
132 }
133
134 #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
135 /* wake up when 80% fifo full */
136 #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
137
138 static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
139                                                 struct spi_transfer *t)
140 {
141         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
142         struct mpc52xx_psc __iomem *psc = mps->psc;
143         struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
144         unsigned rb = 0;        /* number of bytes receieved */
145         unsigned sb = 0;        /* number of bytes sent */
146         unsigned char *rx_buf = (unsigned char *)t->rx_buf;
147         unsigned char *tx_buf = (unsigned char *)t->tx_buf;
148         unsigned rfalarm;
149         unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
150         unsigned recv_at_once;
151
152         if (!t->tx_buf && !t->rx_buf && t->len)
153                 return -EINVAL;
154
155         /* enable transmiter/receiver */
156         out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
157         while (rb < t->len) {
158                 if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
159                         rfalarm = MPC52xx_PSC_RFALARM;
160                 } else {
161                         send_at_once = t->len - sb;
162                         rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
163                 }
164
165                 dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
166                 for (; send_at_once; sb++, send_at_once--) {
167                         /* set EOF flag before the last word is sent */
168                         if (send_at_once == 1)
169                                 out_8(&psc->ircr2, 0x01);
170
171                         if (tx_buf)
172                                 out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
173                         else
174                                 out_8(&psc->mpc52xx_psc_buffer_8, 0);
175                 }
176
177
178                 /* enable interrupts and wait for wake up
179                  * if just one byte is expected the Rx FIFO genererates no
180                  * FFULL interrupt, so activate the RxRDY interrupt
181                  */
182                 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
183                 if (t->len - rb == 1) {
184                         out_8(&psc->mode, 0);
185                 } else {
186                         out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
187                         out_be16(&fifo->rfalarm, rfalarm);
188                 }
189                 out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
190                 wait_for_completion(&mps->done);
191                 recv_at_once = in_be16(&fifo->rfnum);
192                 dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
193
194                 send_at_once = recv_at_once;
195                 if (rx_buf) {
196                         for (; recv_at_once; rb++, recv_at_once--)
197                                 rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
198                 } else {
199                         for (; recv_at_once; rb++, recv_at_once--)
200                                 in_8(&psc->mpc52xx_psc_buffer_8);
201                 }
202         }
203         /* disable transmiter/receiver */
204         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
205
206         return 0;
207 }
208
209 static void mpc52xx_psc_spi_work(struct work_struct *work)
210 {
211         struct mpc52xx_psc_spi *mps =
212                 container_of(work, struct mpc52xx_psc_spi, work);
213
214         spin_lock_irq(&mps->lock);
215         mps->busy = 1;
216         while (!list_empty(&mps->queue)) {
217                 struct spi_message *m;
218                 struct spi_device *spi;
219                 struct spi_transfer *t = NULL;
220                 unsigned cs_change;
221                 int status;
222
223                 m = container_of(mps->queue.next, struct spi_message, queue);
224                 list_del_init(&m->queue);
225                 spin_unlock_irq(&mps->lock);
226
227                 spi = m->spi;
228                 cs_change = 1;
229                 status = 0;
230                 list_for_each_entry (t, &m->transfers, transfer_list) {
231                         if (t->bits_per_word || t->speed_hz) {
232                                 status = mpc52xx_psc_spi_transfer_setup(spi, t);
233                                 if (status < 0)
234                                         break;
235                         }
236
237                         if (cs_change)
238                                 mpc52xx_psc_spi_activate_cs(spi);
239                         cs_change = t->cs_change;
240
241                         status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
242                         if (status)
243                                 break;
244                         m->actual_length += t->len;
245
246                         if (t->delay_usecs)
247                                 udelay(t->delay_usecs);
248
249                         if (cs_change)
250                                 mpc52xx_psc_spi_deactivate_cs(spi);
251                 }
252
253                 m->status = status;
254                 m->complete(m->context);
255
256                 if (status || !cs_change)
257                         mpc52xx_psc_spi_deactivate_cs(spi);
258
259                 mpc52xx_psc_spi_transfer_setup(spi, NULL);
260
261                 spin_lock_irq(&mps->lock);
262         }
263         mps->busy = 0;
264         spin_unlock_irq(&mps->lock);
265 }
266
267 /* the spi->mode bits understood by this driver: */
268 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
269
270 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
271 {
272         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
273         struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
274         unsigned long flags;
275
276         if (spi->bits_per_word%8)
277                 return -EINVAL;
278
279         if (spi->mode & ~MODEBITS) {
280                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
281                         spi->mode & ~MODEBITS);
282                 return -EINVAL;
283         }
284
285         if (!cs) {
286                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
287                 if (!cs)
288                         return -ENOMEM;
289                 spi->controller_state = cs;
290         }
291
292         cs->bits_per_word = spi->bits_per_word;
293         cs->speed_hz = spi->max_speed_hz;
294
295         spin_lock_irqsave(&mps->lock, flags);
296         if (!mps->busy)
297                 mpc52xx_psc_spi_deactivate_cs(spi);
298         spin_unlock_irqrestore(&mps->lock, flags);
299
300         return 0;
301 }
302
303 static int mpc52xx_psc_spi_transfer(struct spi_device *spi,
304                 struct spi_message *m)
305 {
306         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
307         unsigned long flags;
308
309         m->actual_length = 0;
310         m->status = -EINPROGRESS;
311
312         spin_lock_irqsave(&mps->lock, flags);
313         list_add_tail(&m->queue, &mps->queue);
314         queue_work(mps->workqueue, &mps->work);
315         spin_unlock_irqrestore(&mps->lock, flags);
316
317         return 0;
318 }
319
320 static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
321 {
322         kfree(spi->controller_state);
323 }
324
325 static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
326 {
327         struct mpc52xx_psc __iomem *psc = mps->psc;
328         struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
329         u32 mclken_div;
330         int ret = 0;
331
332         /* default sysclk is 512MHz */
333         mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
334         mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
335
336         /* Reset the PSC into a known state */
337         out_8(&psc->command, MPC52xx_PSC_RST_RX);
338         out_8(&psc->command, MPC52xx_PSC_RST_TX);
339         out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
340
341         /* Disable interrupts, interrupts are based on alarm level */
342         out_be16(&psc->mpc52xx_psc_imr, 0);
343         out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
344         out_8(&fifo->rfcntl, 0);
345         out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
346
347         /* Configure 8bit codec mode as a SPI master and use EOF flags */
348         /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
349         out_be32(&psc->sicr, 0x0180C800);
350         out_be16(&psc->ccr, 0x070F); /* by default SPI Clk 1MHz */
351
352         /* Set 2ms DTL delay */
353         out_8(&psc->ctur, 0x00);
354         out_8(&psc->ctlr, 0x84);
355
356         mps->bits_per_word = 8;
357
358         return ret;
359 }
360
361 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
362 {
363         struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
364         struct mpc52xx_psc __iomem *psc = mps->psc;
365
366         /* disable interrupt and wake up the work queue */
367         if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
368                 out_be16(&psc->mpc52xx_psc_imr, 0);
369                 complete(&mps->done);
370                 return IRQ_HANDLED;
371         }
372         return IRQ_NONE;
373 }
374
375 /* bus_num is used only for the case dev->platform_data == NULL */
376 static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
377                                 u32 size, unsigned int irq, s16 bus_num)
378 {
379         struct fsl_spi_platform_data *pdata = dev->platform_data;
380         struct mpc52xx_psc_spi *mps;
381         struct spi_master *master;
382         int ret;
383
384         master = spi_alloc_master(dev, sizeof *mps);
385         if (master == NULL)
386                 return -ENOMEM;
387
388         dev_set_drvdata(dev, master);
389         mps = spi_master_get_devdata(master);
390
391         mps->irq = irq;
392         if (pdata == NULL) {
393                 dev_warn(dev, "probe called without platform data, no "
394                                 "(de)activate_cs function will be called\n");
395                 mps->activate_cs = NULL;
396                 mps->deactivate_cs = NULL;
397                 mps->sysclk = 0;
398                 master->bus_num = bus_num;
399                 master->num_chipselect = 255;
400         } else {
401                 mps->activate_cs = pdata->activate_cs;
402                 mps->deactivate_cs = pdata->deactivate_cs;
403                 mps->sysclk = pdata->sysclk;
404                 master->bus_num = pdata->bus_num;
405                 master->num_chipselect = pdata->max_chipselect;
406         }
407         master->setup = mpc52xx_psc_spi_setup;
408         master->transfer = mpc52xx_psc_spi_transfer;
409         master->cleanup = mpc52xx_psc_spi_cleanup;
410
411         mps->psc = ioremap(regaddr, size);
412         if (!mps->psc) {
413                 dev_err(dev, "could not ioremap I/O port range\n");
414                 ret = -EFAULT;
415                 goto free_master;
416         }
417         /* On the 5200, fifo regs are immediately ajacent to the psc regs */
418         mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
419
420         ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
421                                 mps);
422         if (ret)
423                 goto free_master;
424
425         ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
426         if (ret < 0)
427                 goto free_irq;
428
429         spin_lock_init(&mps->lock);
430         init_completion(&mps->done);
431         INIT_WORK(&mps->work, mpc52xx_psc_spi_work);
432         INIT_LIST_HEAD(&mps->queue);
433
434         mps->workqueue = create_singlethread_workqueue(
435                 master->dev.parent->bus_id);
436         if (mps->workqueue == NULL) {
437                 ret = -EBUSY;
438                 goto free_irq;
439         }
440
441         ret = spi_register_master(master);
442         if (ret < 0)
443                 goto unreg_master;
444
445         return ret;
446
447 unreg_master:
448         destroy_workqueue(mps->workqueue);
449 free_irq:
450         free_irq(mps->irq, mps);
451 free_master:
452         if (mps->psc)
453                 iounmap(mps->psc);
454         spi_master_put(master);
455
456         return ret;
457 }
458
459 static int __exit mpc52xx_psc_spi_do_remove(struct device *dev)
460 {
461         struct spi_master *master = dev_get_drvdata(dev);
462         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master);
463
464         flush_workqueue(mps->workqueue);
465         destroy_workqueue(mps->workqueue);
466         spi_unregister_master(master);
467         free_irq(mps->irq, mps);
468         if (mps->psc)
469                 iounmap(mps->psc);
470
471         return 0;
472 }
473
474 #if !defined(CONFIG_PPC_MERGE)
475 static int __init mpc52xx_psc_spi_probe(struct platform_device *dev)
476 {
477         switch(dev->id) {
478         case 1:
479         case 2:
480         case 3:
481         case 6:
482                 return mpc52xx_psc_spi_do_probe(&dev->dev,
483                         MPC52xx_PA(MPC52xx_PSCx_OFFSET(dev->id)),
484                         MPC52xx_PSC_SIZE, platform_get_irq(dev, 0), dev->id);
485         default:
486                 return -EINVAL;
487         }
488 }
489
490 static int __exit mpc52xx_psc_spi_remove(struct platform_device *dev)
491 {
492         return mpc52xx_psc_spi_do_remove(&dev->dev);
493 }
494
495 /* work with hotplug and coldplug */
496 MODULE_ALIAS("platform:mpc52xx-psc-spi");
497
498 static struct platform_driver mpc52xx_psc_spi_platform_driver = {
499         .remove = __exit_p(mpc52xx_psc_spi_remove),
500         .driver = {
501                 .name = "mpc52xx-psc-spi",
502                 .owner = THIS_MODULE,
503         },
504 };
505
506 static int __init mpc52xx_psc_spi_init(void)
507 {
508         return platform_driver_probe(&mpc52xx_psc_spi_platform_driver,
509                         mpc52xx_psc_spi_probe);
510 }
511 module_init(mpc52xx_psc_spi_init);
512
513 static void __exit mpc52xx_psc_spi_exit(void)
514 {
515         platform_driver_unregister(&mpc52xx_psc_spi_platform_driver);
516 }
517 module_exit(mpc52xx_psc_spi_exit);
518
519 #else   /* defined(CONFIG_PPC_MERGE) */
520
521 static int __init mpc52xx_psc_spi_of_probe(struct of_device *op,
522         const struct of_device_id *match)
523 {
524         const u32 *regaddr_p;
525         u64 regaddr64, size64;
526         s16 id = -1;
527
528         regaddr_p = of_get_address(op->node, 0, &size64, NULL);
529         if (!regaddr_p) {
530                 printk(KERN_ERR "Invalid PSC address\n");
531                 return -EINVAL;
532         }
533         regaddr64 = of_translate_address(op->node, regaddr_p);
534
535         /* get PSC id (1..6, used by port_config) */
536         if (op->dev.platform_data == NULL) {
537                 const u32 *psc_nump;
538
539                 psc_nump = of_get_property(op->node, "cell-index", NULL);
540                 if (!psc_nump || *psc_nump > 5) {
541                         printk(KERN_ERR "mpc52xx_psc_spi: Device node %s has invalid "
542                                         "cell-index property\n", op->node->full_name);
543                         return -EINVAL;
544                 }
545                 id = *psc_nump + 1;
546         }
547
548         return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
549                                         irq_of_parse_and_map(op->node, 0), id);
550 }
551
552 static int __exit mpc52xx_psc_spi_of_remove(struct of_device *op)
553 {
554         return mpc52xx_psc_spi_do_remove(&op->dev);
555 }
556
557 static struct of_device_id mpc52xx_psc_spi_of_match[] = {
558         { .compatible = "fsl,mpc5200-psc-spi", },
559         { .compatible = "mpc5200-psc-spi", }, /* old */
560         {}
561 };
562
563 MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
564
565 static struct of_platform_driver mpc52xx_psc_spi_of_driver = {
566         .owner = THIS_MODULE,
567         .name = "mpc52xx-psc-spi",
568         .match_table = mpc52xx_psc_spi_of_match,
569         .probe = mpc52xx_psc_spi_of_probe,
570         .remove = __exit_p(mpc52xx_psc_spi_of_remove),
571         .driver = {
572                 .name = "mpc52xx-psc-spi",
573                 .owner = THIS_MODULE,
574         },
575 };
576
577 static int __init mpc52xx_psc_spi_init(void)
578 {
579         return of_register_platform_driver(&mpc52xx_psc_spi_of_driver);
580 }
581 module_init(mpc52xx_psc_spi_init);
582
583 static void __exit mpc52xx_psc_spi_exit(void)
584 {
585         of_unregister_platform_driver(&mpc52xx_psc_spi_of_driver);
586 }
587 module_exit(mpc52xx_psc_spi_exit);
588
589 #endif  /* defined(CONFIG_PPC_MERGE) */
590
591 MODULE_AUTHOR("Dragos Carp");
592 MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
593 MODULE_LICENSE("GPL");