1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * MPC52xx PSC in SPI mode driver.
4 *
5 * Maintainer: Dragos Carp
6 *
7 * Copyright (C) 2006 TOPTICA Photonics AG.
8 */
9
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/errno.h>
13 #include <linux/interrupt.h>
14 #include <linux/of_address.h>
15 #include <linux/of_platform.h>
16 #include <linux/workqueue.h>
17 #include <linux/completion.h>
18 #include <linux/io.h>
19 #include <linux/delay.h>
20 #include <linux/spi/spi.h>
21 #include <linux/fsl_devices.h>
22 #include <linux/slab.h>
23
24 #include <asm/mpc52xx.h>
25 #include <asm/mpc52xx_psc.h>
26
27 #define MCLK 20000000 /* PSC port MClk in hz */
28
29 struct mpc52xx_psc_spi {
30 /* fsl_spi_platform data */
31 void (*cs_control)(struct spi_device *spi, bool on);
32 u32 sysclk;
33
34 /* driver internal data */
35 struct mpc52xx_psc __iomem *psc;
36 struct mpc52xx_psc_fifo __iomem *fifo;
37 unsigned int irq;
38 u8 bits_per_word;
39 u8 busy;
40
41 struct work_struct work;
42
43 struct list_head queue;
44 spinlock_t lock;
45
46 struct completion done;
47 };
48
49 /* controller state */
50 struct mpc52xx_psc_spi_cs {
51 int bits_per_word;
52 int speed_hz;
53 };
54
55 /* set clock freq, clock ramp, bits per work
56 * if t is NULL then reset the values to the default values
57 */
mpc52xx_psc_spi_transfer_setup(struct spi_device * spi,struct spi_transfer * t)58 static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
59 struct spi_transfer *t)
60 {
61 struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
62
63 cs->speed_hz = (t && t->speed_hz)
64 ? t->speed_hz : spi->max_speed_hz;
65 cs->bits_per_word = (t && t->bits_per_word)
66 ? t->bits_per_word : spi->bits_per_word;
67 cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
68 return 0;
69 }
70
mpc52xx_psc_spi_activate_cs(struct spi_device * spi)71 static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
72 {
73 struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
74 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
75 struct mpc52xx_psc __iomem *psc = mps->psc;
76 u32 sicr;
77 u16 ccr;
78
79 sicr = in_be32(&psc->sicr);
80
81 /* Set clock phase and polarity */
82 if (spi->mode & SPI_CPHA)
83 sicr |= 0x00001000;
84 else
85 sicr &= ~0x00001000;
86 if (spi->mode & SPI_CPOL)
87 sicr |= 0x00002000;
88 else
89 sicr &= ~0x00002000;
90
91 if (spi->mode & SPI_LSB_FIRST)
92 sicr |= 0x10000000;
93 else
94 sicr &= ~0x10000000;
95 out_be32(&psc->sicr, sicr);
96
97 /* Set clock frequency and bits per word
98 * Because psc->ccr is defined as 16bit register instead of 32bit
99 * just set the lower byte of BitClkDiv
100 */
101 ccr = in_be16((u16 __iomem *)&psc->ccr);
102 ccr &= 0xFF00;
103 if (cs->speed_hz)
104 ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
105 else /* by default SPI Clk 1MHz */
106 ccr |= (MCLK / 1000000 - 1) & 0xFF;
107 out_be16((u16 __iomem *)&psc->ccr, ccr);
108 mps->bits_per_word = cs->bits_per_word;
109
110 if (mps->cs_control)
111 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
112 }
113
mpc52xx_psc_spi_deactivate_cs(struct spi_device * spi)114 static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
115 {
116 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
117
118 if (mps->cs_control)
119 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
120 }
121
122 #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
123 /* wake up when 80% fifo full */
124 #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
125
mpc52xx_psc_spi_transfer_rxtx(struct spi_device * spi,struct spi_transfer * t)126 static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
127 struct spi_transfer *t)
128 {
129 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
130 struct mpc52xx_psc __iomem *psc = mps->psc;
131 struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
132 unsigned rb = 0; /* number of bytes receieved */
133 unsigned sb = 0; /* number of bytes sent */
134 unsigned char *rx_buf = (unsigned char *)t->rx_buf;
135 unsigned char *tx_buf = (unsigned char *)t->tx_buf;
136 unsigned rfalarm;
137 unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
138 unsigned recv_at_once;
139 int last_block = 0;
140
141 if (!t->tx_buf && !t->rx_buf && t->len)
142 return -EINVAL;
143
144 /* enable transmiter/receiver */
145 out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
146 while (rb < t->len) {
147 if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
148 rfalarm = MPC52xx_PSC_RFALARM;
149 last_block = 0;
150 } else {
151 send_at_once = t->len - sb;
152 rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
153 last_block = 1;
154 }
155
156 dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
157 for (; send_at_once; sb++, send_at_once--) {
158 /* set EOF flag before the last word is sent */
159 if (send_at_once == 1 && last_block)
160 out_8(&psc->ircr2, 0x01);
161
162 if (tx_buf)
163 out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
164 else
165 out_8(&psc->mpc52xx_psc_buffer_8, 0);
166 }
167
168
169 /* enable interrupts and wait for wake up
170 * if just one byte is expected the Rx FIFO genererates no
171 * FFULL interrupt, so activate the RxRDY interrupt
172 */
173 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
174 if (t->len - rb == 1) {
175 out_8(&psc->mode, 0);
176 } else {
177 out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
178 out_be16(&fifo->rfalarm, rfalarm);
179 }
180 out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
181 wait_for_completion(&mps->done);
182 recv_at_once = in_be16(&fifo->rfnum);
183 dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
184
185 send_at_once = recv_at_once;
186 if (rx_buf) {
187 for (; recv_at_once; rb++, recv_at_once--)
188 rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
189 } else {
190 for (; recv_at_once; rb++, recv_at_once--)
191 in_8(&psc->mpc52xx_psc_buffer_8);
192 }
193 }
194 /* disable transmiter/receiver */
195 out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
196
197 return 0;
198 }
199
mpc52xx_psc_spi_work(struct work_struct * work)200 static void mpc52xx_psc_spi_work(struct work_struct *work)
201 {
202 struct mpc52xx_psc_spi *mps =
203 container_of(work, struct mpc52xx_psc_spi, work);
204
205 spin_lock_irq(&mps->lock);
206 mps->busy = 1;
207 while (!list_empty(&mps->queue)) {
208 struct spi_message *m;
209 struct spi_device *spi;
210 struct spi_transfer *t = NULL;
211 unsigned cs_change;
212 int status;
213
214 m = container_of(mps->queue.next, struct spi_message, queue);
215 list_del_init(&m->queue);
216 spin_unlock_irq(&mps->lock);
217
218 spi = m->spi;
219 cs_change = 1;
220 status = 0;
221 list_for_each_entry (t, &m->transfers, transfer_list) {
222 if (t->bits_per_word || t->speed_hz) {
223 status = mpc52xx_psc_spi_transfer_setup(spi, t);
224 if (status < 0)
225 break;
226 }
227
228 if (cs_change)
229 mpc52xx_psc_spi_activate_cs(spi);
230 cs_change = t->cs_change;
231
232 status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
233 if (status)
234 break;
235 m->actual_length += t->len;
236
237 spi_transfer_delay_exec(t);
238
239 if (cs_change)
240 mpc52xx_psc_spi_deactivate_cs(spi);
241 }
242
243 m->status = status;
244 if (m->complete)
245 m->complete(m->context);
246
247 if (status || !cs_change)
248 mpc52xx_psc_spi_deactivate_cs(spi);
249
250 mpc52xx_psc_spi_transfer_setup(spi, NULL);
251
252 spin_lock_irq(&mps->lock);
253 }
254 mps->busy = 0;
255 spin_unlock_irq(&mps->lock);
256 }
257
mpc52xx_psc_spi_setup(struct spi_device * spi)258 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
259 {
260 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
261 struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
262 unsigned long flags;
263
264 if (spi->bits_per_word%8)
265 return -EINVAL;
266
267 if (!cs) {
268 cs = kzalloc(sizeof *cs, GFP_KERNEL);
269 if (!cs)
270 return -ENOMEM;
271 spi->controller_state = cs;
272 }
273
274 cs->bits_per_word = spi->bits_per_word;
275 cs->speed_hz = spi->max_speed_hz;
276
277 spin_lock_irqsave(&mps->lock, flags);
278 if (!mps->busy)
279 mpc52xx_psc_spi_deactivate_cs(spi);
280 spin_unlock_irqrestore(&mps->lock, flags);
281
282 return 0;
283 }
284
mpc52xx_psc_spi_transfer(struct spi_device * spi,struct spi_message * m)285 static int mpc52xx_psc_spi_transfer(struct spi_device *spi,
286 struct spi_message *m)
287 {
288 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
289 unsigned long flags;
290
291 m->actual_length = 0;
292 m->status = -EINPROGRESS;
293
294 spin_lock_irqsave(&mps->lock, flags);
295 list_add_tail(&m->queue, &mps->queue);
296 schedule_work(&mps->work);
297 spin_unlock_irqrestore(&mps->lock, flags);
298
299 return 0;
300 }
301
mpc52xx_psc_spi_cleanup(struct spi_device * spi)302 static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
303 {
304 kfree(spi->controller_state);
305 }
306
mpc52xx_psc_spi_port_config(int psc_id,struct mpc52xx_psc_spi * mps)307 static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
308 {
309 struct mpc52xx_psc __iomem *psc = mps->psc;
310 struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
311 u32 mclken_div;
312 int ret;
313
314 /* default sysclk is 512MHz */
315 mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
316 ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
317 if (ret)
318 return ret;
319
320 /* Reset the PSC into a known state */
321 out_8(&psc->command, MPC52xx_PSC_RST_RX);
322 out_8(&psc->command, MPC52xx_PSC_RST_TX);
323 out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
324
325 /* Disable interrupts, interrupts are based on alarm level */
326 out_be16(&psc->mpc52xx_psc_imr, 0);
327 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
328 out_8(&fifo->rfcntl, 0);
329 out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
330
331 /* Configure 8bit codec mode as a SPI master and use EOF flags */
332 /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
333 out_be32(&psc->sicr, 0x0180C800);
334 out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */
335
336 /* Set 2ms DTL delay */
337 out_8(&psc->ctur, 0x00);
338 out_8(&psc->ctlr, 0x84);
339
340 mps->bits_per_word = 8;
341
342 return 0;
343 }
344
mpc52xx_psc_spi_isr(int irq,void * dev_id)345 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
346 {
347 struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
348 struct mpc52xx_psc __iomem *psc = mps->psc;
349
350 /* disable interrupt and wake up the work queue */
351 if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
352 out_be16(&psc->mpc52xx_psc_imr, 0);
353 complete(&mps->done);
354 return IRQ_HANDLED;
355 }
356 return IRQ_NONE;
357 }
358
359 /* bus_num is used only for the case dev->platform_data == NULL */
mpc52xx_psc_spi_do_probe(struct device * dev,u32 regaddr,u32 size,unsigned int irq,s16 bus_num)360 static int mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
361 u32 size, unsigned int irq, s16 bus_num)
362 {
363 struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
364 struct mpc52xx_psc_spi *mps;
365 struct spi_master *master;
366 int ret;
367
368 master = spi_alloc_master(dev, sizeof *mps);
369 if (master == NULL)
370 return -ENOMEM;
371
372 dev_set_drvdata(dev, master);
373 mps = spi_master_get_devdata(master);
374
375 /* the spi->mode bits understood by this driver: */
376 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
377
378 mps->irq = irq;
379 if (pdata == NULL) {
380 dev_warn(dev,
381 "probe called without platform data, no cs_control function will be called\n");
382 mps->cs_control = NULL;
383 mps->sysclk = 0;
384 master->bus_num = bus_num;
385 master->num_chipselect = 255;
386 } else {
387 mps->cs_control = pdata->cs_control;
388 mps->sysclk = pdata->sysclk;
389 master->bus_num = pdata->bus_num;
390 master->num_chipselect = pdata->max_chipselect;
391 }
392 master->setup = mpc52xx_psc_spi_setup;
393 master->transfer = mpc52xx_psc_spi_transfer;
394 master->cleanup = mpc52xx_psc_spi_cleanup;
395 master->dev.of_node = dev->of_node;
396
397 mps->psc = ioremap(regaddr, size);
398 if (!mps->psc) {
399 dev_err(dev, "could not ioremap I/O port range\n");
400 ret = -EFAULT;
401 goto free_master;
402 }
403 /* On the 5200, fifo regs are immediately ajacent to the psc regs */
404 mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
405
406 ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
407 mps);
408 if (ret)
409 goto free_master;
410
411 ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
412 if (ret < 0) {
413 dev_err(dev, "can't configure PSC! Is it capable of SPI?\n");
414 goto free_irq;
415 }
416
417 spin_lock_init(&mps->lock);
418 init_completion(&mps->done);
419 INIT_WORK(&mps->work, mpc52xx_psc_spi_work);
420 INIT_LIST_HEAD(&mps->queue);
421
422 ret = spi_register_master(master);
423 if (ret < 0)
424 goto free_irq;
425
426 return ret;
427
428 free_irq:
429 free_irq(mps->irq, mps);
430 free_master:
431 if (mps->psc)
432 iounmap(mps->psc);
433 spi_master_put(master);
434
435 return ret;
436 }
437
mpc52xx_psc_spi_of_probe(struct platform_device * op)438 static int mpc52xx_psc_spi_of_probe(struct platform_device *op)
439 {
440 const u32 *regaddr_p;
441 u64 regaddr64, size64;
442 s16 id = -1;
443
444 regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL);
445 if (!regaddr_p) {
446 dev_err(&op->dev, "Invalid PSC address\n");
447 return -EINVAL;
448 }
449 regaddr64 = of_translate_address(op->dev.of_node, regaddr_p);
450
451 /* get PSC id (1..6, used by port_config) */
452 if (op->dev.platform_data == NULL) {
453 const u32 *psc_nump;
454
455 psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL);
456 if (!psc_nump || *psc_nump > 5) {
457 dev_err(&op->dev, "Invalid cell-index property\n");
458 return -EINVAL;
459 }
460 id = *psc_nump + 1;
461 }
462
463 return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
464 irq_of_parse_and_map(op->dev.of_node, 0), id);
465 }
466
mpc52xx_psc_spi_of_remove(struct platform_device * op)467 static int mpc52xx_psc_spi_of_remove(struct platform_device *op)
468 {
469 struct spi_master *master = spi_master_get(platform_get_drvdata(op));
470 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master);
471
472 flush_work(&mps->work);
473 spi_unregister_master(master);
474 free_irq(mps->irq, mps);
475 if (mps->psc)
476 iounmap(mps->psc);
477 spi_master_put(master);
478
479 return 0;
480 }
481
482 static const struct of_device_id mpc52xx_psc_spi_of_match[] = {
483 { .compatible = "fsl,mpc5200-psc-spi", },
484 { .compatible = "mpc5200-psc-spi", }, /* old */
485 {}
486 };
487
488 MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
489
490 static struct platform_driver mpc52xx_psc_spi_of_driver = {
491 .probe = mpc52xx_psc_spi_of_probe,
492 .remove = mpc52xx_psc_spi_of_remove,
493 .driver = {
494 .name = "mpc52xx-psc-spi",
495 .of_match_table = mpc52xx_psc_spi_of_match,
496 },
497 };
498 module_platform_driver(mpc52xx_psc_spi_of_driver);
499
500 MODULE_AUTHOR("Dragos Carp");
501 MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
502 MODULE_LICENSE("GPL");
503
