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 #include <linux/of_irq.h>
24
25 #include <asm/mpc52xx.h>
26 #include <asm/mpc52xx_psc.h>
27
28 #define MCLK 20000000 /* PSC port MClk in hz */
29
30 struct mpc52xx_psc_spi {
31 /* fsl_spi_platform data */
32 void (*cs_control)(struct spi_device *spi, bool on);
33 u32 sysclk;
34
35 /* driver internal data */
36 struct mpc52xx_psc __iomem *psc;
37 struct mpc52xx_psc_fifo __iomem *fifo;
38 unsigned int irq;
39 u8 bits_per_word;
40
41 struct completion done;
42 };
43
44 /* controller state */
45 struct mpc52xx_psc_spi_cs {
46 int bits_per_word;
47 int speed_hz;
48 };
49
50 /* set clock freq, clock ramp, bits per work
51 * if t is NULL then reset the values to the default values
52 */
mpc52xx_psc_spi_transfer_setup(struct spi_device * spi,struct spi_transfer * t)53 static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
54 struct spi_transfer *t)
55 {
56 struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
57
58 cs->speed_hz = (t && t->speed_hz)
59 ? t->speed_hz : spi->max_speed_hz;
60 cs->bits_per_word = (t && t->bits_per_word)
61 ? t->bits_per_word : spi->bits_per_word;
62 cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
63 return 0;
64 }
65
mpc52xx_psc_spi_activate_cs(struct spi_device * spi)66 static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
67 {
68 struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
69 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
70 struct mpc52xx_psc __iomem *psc = mps->psc;
71 u32 sicr;
72 u16 ccr;
73
74 sicr = in_be32(&psc->sicr);
75
76 /* Set clock phase and polarity */
77 if (spi->mode & SPI_CPHA)
78 sicr |= 0x00001000;
79 else
80 sicr &= ~0x00001000;
81 if (spi->mode & SPI_CPOL)
82 sicr |= 0x00002000;
83 else
84 sicr &= ~0x00002000;
85
86 if (spi->mode & SPI_LSB_FIRST)
87 sicr |= 0x10000000;
88 else
89 sicr &= ~0x10000000;
90 out_be32(&psc->sicr, sicr);
91
92 /* Set clock frequency and bits per word
93 * Because psc->ccr is defined as 16bit register instead of 32bit
94 * just set the lower byte of BitClkDiv
95 */
96 ccr = in_be16((u16 __iomem *)&psc->ccr);
97 ccr &= 0xFF00;
98 if (cs->speed_hz)
99 ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
100 else /* by default SPI Clk 1MHz */
101 ccr |= (MCLK / 1000000 - 1) & 0xFF;
102 out_be16((u16 __iomem *)&psc->ccr, ccr);
103 mps->bits_per_word = cs->bits_per_word;
104
105 if (mps->cs_control)
106 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
107 }
108
mpc52xx_psc_spi_deactivate_cs(struct spi_device * spi)109 static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
110 {
111 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
112
113 if (mps->cs_control)
114 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
115 }
116
117 #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
118 /* wake up when 80% fifo full */
119 #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
120
mpc52xx_psc_spi_transfer_rxtx(struct spi_device * spi,struct spi_transfer * t)121 static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
122 struct spi_transfer *t)
123 {
124 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
125 struct mpc52xx_psc __iomem *psc = mps->psc;
126 struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
127 unsigned rb = 0; /* number of bytes receieved */
128 unsigned sb = 0; /* number of bytes sent */
129 unsigned char *rx_buf = (unsigned char *)t->rx_buf;
130 unsigned char *tx_buf = (unsigned char *)t->tx_buf;
131 unsigned rfalarm;
132 unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
133 unsigned recv_at_once;
134 int last_block = 0;
135
136 if (!t->tx_buf && !t->rx_buf && t->len)
137 return -EINVAL;
138
139 /* enable transmiter/receiver */
140 out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
141 while (rb < t->len) {
142 if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
143 rfalarm = MPC52xx_PSC_RFALARM;
144 last_block = 0;
145 } else {
146 send_at_once = t->len - sb;
147 rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
148 last_block = 1;
149 }
150
151 dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
152 for (; send_at_once; sb++, send_at_once--) {
153 /* set EOF flag before the last word is sent */
154 if (send_at_once == 1 && last_block)
155 out_8(&psc->ircr2, 0x01);
156
157 if (tx_buf)
158 out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
159 else
160 out_8(&psc->mpc52xx_psc_buffer_8, 0);
161 }
162
163
164 /* enable interrupts and wait for wake up
165 * if just one byte is expected the Rx FIFO genererates no
166 * FFULL interrupt, so activate the RxRDY interrupt
167 */
168 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
169 if (t->len - rb == 1) {
170 out_8(&psc->mode, 0);
171 } else {
172 out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
173 out_be16(&fifo->rfalarm, rfalarm);
174 }
175 out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
176 wait_for_completion(&mps->done);
177 recv_at_once = in_be16(&fifo->rfnum);
178 dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
179
180 send_at_once = recv_at_once;
181 if (rx_buf) {
182 for (; recv_at_once; rb++, recv_at_once--)
183 rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
184 } else {
185 for (; recv_at_once; rb++, recv_at_once--)
186 in_8(&psc->mpc52xx_psc_buffer_8);
187 }
188 }
189 /* disable transmiter/receiver */
190 out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
191
192 return 0;
193 }
194
mpc52xx_psc_spi_transfer_one_message(struct spi_controller * ctlr,struct spi_message * m)195 int mpc52xx_psc_spi_transfer_one_message(struct spi_controller *ctlr,
196 struct spi_message *m)
197 {
198 struct spi_device *spi;
199 struct spi_transfer *t = NULL;
200 unsigned cs_change;
201 int status;
202
203 spi = m->spi;
204 cs_change = 1;
205 status = 0;
206 list_for_each_entry (t, &m->transfers, transfer_list) {
207 if (t->bits_per_word || t->speed_hz) {
208 status = mpc52xx_psc_spi_transfer_setup(spi, t);
209 if (status < 0)
210 break;
211 }
212
213 if (cs_change)
214 mpc52xx_psc_spi_activate_cs(spi);
215 cs_change = t->cs_change;
216
217 status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
218 if (status)
219 break;
220 m->actual_length += t->len;
221
222 spi_transfer_delay_exec(t);
223
224 if (cs_change)
225 mpc52xx_psc_spi_deactivate_cs(spi);
226 }
227
228 m->status = status;
229 if (status || !cs_change)
230 mpc52xx_psc_spi_deactivate_cs(spi);
231
232 mpc52xx_psc_spi_transfer_setup(spi, NULL);
233
234 spi_finalize_current_message(ctlr);
235
236 return 0;
237 }
238
mpc52xx_psc_spi_setup(struct spi_device * spi)239 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
240 {
241 struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
242
243 if (spi->bits_per_word%8)
244 return -EINVAL;
245
246 if (!cs) {
247 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
248 if (!cs)
249 return -ENOMEM;
250 spi->controller_state = cs;
251 }
252
253 cs->bits_per_word = spi->bits_per_word;
254 cs->speed_hz = spi->max_speed_hz;
255
256 return 0;
257 }
258
mpc52xx_psc_spi_cleanup(struct spi_device * spi)259 static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
260 {
261 kfree(spi->controller_state);
262 }
263
mpc52xx_psc_spi_port_config(int psc_id,struct mpc52xx_psc_spi * mps)264 static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
265 {
266 struct mpc52xx_psc __iomem *psc = mps->psc;
267 struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
268 u32 mclken_div;
269 int ret;
270
271 /* default sysclk is 512MHz */
272 mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
273 ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
274 if (ret)
275 return ret;
276
277 /* Reset the PSC into a known state */
278 out_8(&psc->command, MPC52xx_PSC_RST_RX);
279 out_8(&psc->command, MPC52xx_PSC_RST_TX);
280 out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
281
282 /* Disable interrupts, interrupts are based on alarm level */
283 out_be16(&psc->mpc52xx_psc_imr, 0);
284 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
285 out_8(&fifo->rfcntl, 0);
286 out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
287
288 /* Configure 8bit codec mode as a SPI master and use EOF flags */
289 /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
290 out_be32(&psc->sicr, 0x0180C800);
291 out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */
292
293 /* Set 2ms DTL delay */
294 out_8(&psc->ctur, 0x00);
295 out_8(&psc->ctlr, 0x84);
296
297 mps->bits_per_word = 8;
298
299 return 0;
300 }
301
mpc52xx_psc_spi_isr(int irq,void * dev_id)302 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
303 {
304 struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
305 struct mpc52xx_psc __iomem *psc = mps->psc;
306
307 /* disable interrupt and wake up the work queue */
308 if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
309 out_be16(&psc->mpc52xx_psc_imr, 0);
310 complete(&mps->done);
311 return IRQ_HANDLED;
312 }
313 return IRQ_NONE;
314 }
315
316 /* 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)317 static int mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
318 u32 size, unsigned int irq, s16 bus_num)
319 {
320 struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
321 struct mpc52xx_psc_spi *mps;
322 struct spi_master *master;
323 int ret;
324
325 master = spi_alloc_master(dev, sizeof(*mps));
326 if (master == NULL)
327 return -ENOMEM;
328
329 dev_set_drvdata(dev, master);
330 mps = spi_master_get_devdata(master);
331
332 /* the spi->mode bits understood by this driver: */
333 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
334
335 mps->irq = irq;
336 if (pdata == NULL) {
337 dev_warn(dev,
338 "probe called without platform data, no cs_control function will be called\n");
339 mps->cs_control = NULL;
340 mps->sysclk = 0;
341 master->bus_num = bus_num;
342 master->num_chipselect = 255;
343 } else {
344 mps->cs_control = pdata->cs_control;
345 mps->sysclk = pdata->sysclk;
346 master->bus_num = pdata->bus_num;
347 master->num_chipselect = pdata->max_chipselect;
348 }
349 master->setup = mpc52xx_psc_spi_setup;
350 master->transfer_one_message = mpc52xx_psc_spi_transfer_one_message;
351 master->cleanup = mpc52xx_psc_spi_cleanup;
352 master->dev.of_node = dev->of_node;
353
354 mps->psc = ioremap(regaddr, size);
355 if (!mps->psc) {
356 dev_err(dev, "could not ioremap I/O port range\n");
357 ret = -EFAULT;
358 goto free_master;
359 }
360 /* On the 5200, fifo regs are immediately ajacent to the psc regs */
361 mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
362
363 ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
364 mps);
365 if (ret)
366 goto free_master;
367
368 ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
369 if (ret < 0) {
370 dev_err(dev, "can't configure PSC! Is it capable of SPI?\n");
371 goto free_irq;
372 }
373
374 init_completion(&mps->done);
375
376 ret = spi_register_master(master);
377 if (ret < 0)
378 goto free_irq;
379
380 return ret;
381
382 free_irq:
383 free_irq(mps->irq, mps);
384 free_master:
385 if (mps->psc)
386 iounmap(mps->psc);
387 spi_master_put(master);
388
389 return ret;
390 }
391
mpc52xx_psc_spi_of_probe(struct platform_device * op)392 static int mpc52xx_psc_spi_of_probe(struct platform_device *op)
393 {
394 const u32 *regaddr_p;
395 u64 regaddr64, size64;
396 s16 id = -1;
397
398 regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL);
399 if (!regaddr_p) {
400 dev_err(&op->dev, "Invalid PSC address\n");
401 return -EINVAL;
402 }
403 regaddr64 = of_translate_address(op->dev.of_node, regaddr_p);
404
405 /* get PSC id (1..6, used by port_config) */
406 if (op->dev.platform_data == NULL) {
407 const u32 *psc_nump;
408
409 psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL);
410 if (!psc_nump || *psc_nump > 5) {
411 dev_err(&op->dev, "Invalid cell-index property\n");
412 return -EINVAL;
413 }
414 id = *psc_nump + 1;
415 }
416
417 return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
418 irq_of_parse_and_map(op->dev.of_node, 0), id);
419 }
420
mpc52xx_psc_spi_of_remove(struct platform_device * op)421 static int mpc52xx_psc_spi_of_remove(struct platform_device *op)
422 {
423 struct spi_master *master = spi_master_get(platform_get_drvdata(op));
424 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master);
425
426 spi_unregister_master(master);
427 free_irq(mps->irq, mps);
428 if (mps->psc)
429 iounmap(mps->psc);
430 spi_master_put(master);
431
432 return 0;
433 }
434
435 static const struct of_device_id mpc52xx_psc_spi_of_match[] = {
436 { .compatible = "fsl,mpc5200-psc-spi", },
437 { .compatible = "mpc5200-psc-spi", }, /* old */
438 {}
439 };
440
441 MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
442
443 static struct platform_driver mpc52xx_psc_spi_of_driver = {
444 .probe = mpc52xx_psc_spi_of_probe,
445 .remove = mpc52xx_psc_spi_of_remove,
446 .driver = {
447 .name = "mpc52xx-psc-spi",
448 .of_match_table = mpc52xx_psc_spi_of_match,
449 },
450 };
451 module_platform_driver(mpc52xx_psc_spi_of_driver);
452
453 MODULE_AUTHOR("Dragos Carp");
454 MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
455 MODULE_LICENSE("GPL");
456
