1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Motorola PCAP2 as present in EZX phones
4 *
5 * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
6 * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/platform_device.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/mfd/ezx-pcap.h>
15 #include <linux/spi/spi.h>
16 #include <linux/gpio.h>
17 #include <linux/slab.h>
18
19 #define PCAP_ADC_MAXQ 8
20 struct pcap_adc_request {
21 u8 bank;
22 u8 ch[2];
23 u32 flags;
24 void (*callback)(void *, u16[]);
25 void *data;
26 };
27
28 struct pcap_adc_sync_request {
29 u16 res[2];
30 struct completion completion;
31 };
32
33 struct pcap_chip {
34 struct spi_device *spi;
35
36 /* IO */
37 u32 buf;
38 spinlock_t io_lock;
39
40 /* IRQ */
41 unsigned int irq_base;
42 u32 msr;
43 struct work_struct isr_work;
44 struct work_struct msr_work;
45 struct workqueue_struct *workqueue;
46
47 /* ADC */
48 struct pcap_adc_request *adc_queue[PCAP_ADC_MAXQ];
49 u8 adc_head;
50 u8 adc_tail;
51 spinlock_t adc_lock;
52 };
53
54 /* IO */
ezx_pcap_putget(struct pcap_chip * pcap,u32 * data)55 static int ezx_pcap_putget(struct pcap_chip *pcap, u32 *data)
56 {
57 struct spi_transfer t;
58 struct spi_message m;
59 int status;
60
61 memset(&t, 0, sizeof(t));
62 spi_message_init(&m);
63 t.len = sizeof(u32);
64 spi_message_add_tail(&t, &m);
65
66 pcap->buf = *data;
67 t.tx_buf = (u8 *) &pcap->buf;
68 t.rx_buf = (u8 *) &pcap->buf;
69 status = spi_sync(pcap->spi, &m);
70
71 if (status == 0)
72 *data = pcap->buf;
73
74 return status;
75 }
76
ezx_pcap_write(struct pcap_chip * pcap,u8 reg_num,u32 value)77 int ezx_pcap_write(struct pcap_chip *pcap, u8 reg_num, u32 value)
78 {
79 unsigned long flags;
80 int ret;
81
82 spin_lock_irqsave(&pcap->io_lock, flags);
83 value &= PCAP_REGISTER_VALUE_MASK;
84 value |= PCAP_REGISTER_WRITE_OP_BIT
85 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
86 ret = ezx_pcap_putget(pcap, &value);
87 spin_unlock_irqrestore(&pcap->io_lock, flags);
88
89 return ret;
90 }
91 EXPORT_SYMBOL_GPL(ezx_pcap_write);
92
ezx_pcap_read(struct pcap_chip * pcap,u8 reg_num,u32 * value)93 int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
94 {
95 unsigned long flags;
96 int ret;
97
98 spin_lock_irqsave(&pcap->io_lock, flags);
99 *value = PCAP_REGISTER_READ_OP_BIT
100 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
101
102 ret = ezx_pcap_putget(pcap, value);
103 spin_unlock_irqrestore(&pcap->io_lock, flags);
104
105 return ret;
106 }
107 EXPORT_SYMBOL_GPL(ezx_pcap_read);
108
ezx_pcap_set_bits(struct pcap_chip * pcap,u8 reg_num,u32 mask,u32 val)109 int ezx_pcap_set_bits(struct pcap_chip *pcap, u8 reg_num, u32 mask, u32 val)
110 {
111 unsigned long flags;
112 int ret;
113 u32 tmp = PCAP_REGISTER_READ_OP_BIT |
114 (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
115
116 spin_lock_irqsave(&pcap->io_lock, flags);
117 ret = ezx_pcap_putget(pcap, &tmp);
118 if (ret)
119 goto out_unlock;
120
121 tmp &= (PCAP_REGISTER_VALUE_MASK & ~mask);
122 tmp |= (val & mask) | PCAP_REGISTER_WRITE_OP_BIT |
123 (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
124
125 ret = ezx_pcap_putget(pcap, &tmp);
126 out_unlock:
127 spin_unlock_irqrestore(&pcap->io_lock, flags);
128
129 return ret;
130 }
131 EXPORT_SYMBOL_GPL(ezx_pcap_set_bits);
132
133 /* IRQ */
irq_to_pcap(struct pcap_chip * pcap,int irq)134 int irq_to_pcap(struct pcap_chip *pcap, int irq)
135 {
136 return irq - pcap->irq_base;
137 }
138 EXPORT_SYMBOL_GPL(irq_to_pcap);
139
pcap_to_irq(struct pcap_chip * pcap,int irq)140 int pcap_to_irq(struct pcap_chip *pcap, int irq)
141 {
142 return pcap->irq_base + irq;
143 }
144 EXPORT_SYMBOL_GPL(pcap_to_irq);
145
pcap_mask_irq(struct irq_data * d)146 static void pcap_mask_irq(struct irq_data *d)
147 {
148 struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
149
150 pcap->msr |= 1 << irq_to_pcap(pcap, d->irq);
151 queue_work(pcap->workqueue, &pcap->msr_work);
152 }
153
pcap_unmask_irq(struct irq_data * d)154 static void pcap_unmask_irq(struct irq_data *d)
155 {
156 struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
157
158 pcap->msr &= ~(1 << irq_to_pcap(pcap, d->irq));
159 queue_work(pcap->workqueue, &pcap->msr_work);
160 }
161
162 static struct irq_chip pcap_irq_chip = {
163 .name = "pcap",
164 .irq_disable = pcap_mask_irq,
165 .irq_mask = pcap_mask_irq,
166 .irq_unmask = pcap_unmask_irq,
167 };
168
pcap_msr_work(struct work_struct * work)169 static void pcap_msr_work(struct work_struct *work)
170 {
171 struct pcap_chip *pcap = container_of(work, struct pcap_chip, msr_work);
172
173 ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
174 }
175
pcap_isr_work(struct work_struct * work)176 static void pcap_isr_work(struct work_struct *work)
177 {
178 struct pcap_chip *pcap = container_of(work, struct pcap_chip, isr_work);
179 struct pcap_platform_data *pdata = dev_get_platdata(&pcap->spi->dev);
180 u32 msr, isr, int_sel, service;
181 int irq;
182
183 do {
184 ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
185 ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
186
187 /* We can't service/ack irqs that are assigned to port 2 */
188 if (!(pdata->config & PCAP_SECOND_PORT)) {
189 ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
190 isr &= ~int_sel;
191 }
192
193 ezx_pcap_write(pcap, PCAP_REG_MSR, isr | msr);
194 ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
195
196 service = isr & ~msr;
197 for (irq = pcap->irq_base; service; service >>= 1, irq++) {
198 if (service & 1)
199 generic_handle_irq_safe(irq);
200 }
201 ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
202 } while (gpio_get_value(pdata->gpio));
203 }
204
pcap_irq_handler(struct irq_desc * desc)205 static void pcap_irq_handler(struct irq_desc *desc)
206 {
207 struct pcap_chip *pcap = irq_desc_get_handler_data(desc);
208
209 desc->irq_data.chip->irq_ack(&desc->irq_data);
210 queue_work(pcap->workqueue, &pcap->isr_work);
211 }
212
213 /* ADC */
pcap_set_ts_bits(struct pcap_chip * pcap,u32 bits)214 void pcap_set_ts_bits(struct pcap_chip *pcap, u32 bits)
215 {
216 unsigned long flags;
217 u32 tmp;
218
219 spin_lock_irqsave(&pcap->adc_lock, flags);
220 ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
221 tmp &= ~(PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
222 tmp |= bits & (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
223 ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
224 spin_unlock_irqrestore(&pcap->adc_lock, flags);
225 }
226 EXPORT_SYMBOL_GPL(pcap_set_ts_bits);
227
pcap_disable_adc(struct pcap_chip * pcap)228 static void pcap_disable_adc(struct pcap_chip *pcap)
229 {
230 u32 tmp;
231
232 ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
233 tmp &= ~(PCAP_ADC_ADEN|PCAP_ADC_BATT_I_ADC|PCAP_ADC_BATT_I_POLARITY);
234 ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
235 }
236
pcap_adc_trigger(struct pcap_chip * pcap)237 static void pcap_adc_trigger(struct pcap_chip *pcap)
238 {
239 unsigned long flags;
240 u32 tmp;
241 u8 head;
242
243 spin_lock_irqsave(&pcap->adc_lock, flags);
244 head = pcap->adc_head;
245 if (!pcap->adc_queue[head]) {
246 /* queue is empty, save power */
247 pcap_disable_adc(pcap);
248 spin_unlock_irqrestore(&pcap->adc_lock, flags);
249 return;
250 }
251 /* start conversion on requested bank, save TS_M bits */
252 ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
253 tmp &= (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
254 tmp |= pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
255
256 if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
257 tmp |= PCAP_ADC_AD_SEL1;
258
259 ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
260 spin_unlock_irqrestore(&pcap->adc_lock, flags);
261 ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
262 }
263
pcap_adc_irq(int irq,void * _pcap)264 static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
265 {
266 struct pcap_chip *pcap = _pcap;
267 struct pcap_adc_request *req;
268 u16 res[2];
269 u32 tmp;
270
271 spin_lock(&pcap->adc_lock);
272 req = pcap->adc_queue[pcap->adc_head];
273
274 if (WARN(!req, "adc irq without pending request\n")) {
275 spin_unlock(&pcap->adc_lock);
276 return IRQ_HANDLED;
277 }
278
279 /* read requested channels results */
280 ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
281 tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
282 tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
283 tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
284 ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
285 ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
286 res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
287 res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
288
289 pcap->adc_queue[pcap->adc_head] = NULL;
290 pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
291 spin_unlock(&pcap->adc_lock);
292
293 /* pass the results and release memory */
294 req->callback(req->data, res);
295 kfree(req);
296
297 /* trigger next conversion (if any) on queue */
298 pcap_adc_trigger(pcap);
299
300 return IRQ_HANDLED;
301 }
302
pcap_adc_async(struct pcap_chip * pcap,u8 bank,u32 flags,u8 ch[],void * callback,void * data)303 int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
304 void *callback, void *data)
305 {
306 struct pcap_adc_request *req;
307 unsigned long irq_flags;
308
309 /* This will be freed after we have a result */
310 req = kmalloc(sizeof(struct pcap_adc_request), GFP_KERNEL);
311 if (!req)
312 return -ENOMEM;
313
314 req->bank = bank;
315 req->flags = flags;
316 req->ch[0] = ch[0];
317 req->ch[1] = ch[1];
318 req->callback = callback;
319 req->data = data;
320
321 spin_lock_irqsave(&pcap->adc_lock, irq_flags);
322 if (pcap->adc_queue[pcap->adc_tail]) {
323 spin_unlock_irqrestore(&pcap->adc_lock, irq_flags);
324 kfree(req);
325 return -EBUSY;
326 }
327 pcap->adc_queue[pcap->adc_tail] = req;
328 pcap->adc_tail = (pcap->adc_tail + 1) & (PCAP_ADC_MAXQ - 1);
329 spin_unlock_irqrestore(&pcap->adc_lock, irq_flags);
330
331 /* start conversion */
332 pcap_adc_trigger(pcap);
333
334 return 0;
335 }
336 EXPORT_SYMBOL_GPL(pcap_adc_async);
337
pcap_adc_sync_cb(void * param,u16 res[])338 static void pcap_adc_sync_cb(void *param, u16 res[])
339 {
340 struct pcap_adc_sync_request *req = param;
341
342 req->res[0] = res[0];
343 req->res[1] = res[1];
344 complete(&req->completion);
345 }
346
pcap_adc_sync(struct pcap_chip * pcap,u8 bank,u32 flags,u8 ch[],u16 res[])347 int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
348 u16 res[])
349 {
350 struct pcap_adc_sync_request sync_data;
351 int ret;
352
353 init_completion(&sync_data.completion);
354 ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
355 &sync_data);
356 if (ret)
357 return ret;
358 wait_for_completion(&sync_data.completion);
359 res[0] = sync_data.res[0];
360 res[1] = sync_data.res[1];
361
362 return 0;
363 }
364 EXPORT_SYMBOL_GPL(pcap_adc_sync);
365
366 /* subdevs */
pcap_remove_subdev(struct device * dev,void * unused)367 static int pcap_remove_subdev(struct device *dev, void *unused)
368 {
369 platform_device_unregister(to_platform_device(dev));
370 return 0;
371 }
372
pcap_add_subdev(struct pcap_chip * pcap,struct pcap_subdev * subdev)373 static int pcap_add_subdev(struct pcap_chip *pcap,
374 struct pcap_subdev *subdev)
375 {
376 struct platform_device *pdev;
377 int ret;
378
379 pdev = platform_device_alloc(subdev->name, subdev->id);
380 if (!pdev)
381 return -ENOMEM;
382
383 pdev->dev.parent = &pcap->spi->dev;
384 pdev->dev.platform_data = subdev->platform_data;
385
386 ret = platform_device_add(pdev);
387 if (ret)
388 platform_device_put(pdev);
389
390 return ret;
391 }
392
ezx_pcap_remove(struct spi_device * spi)393 static void ezx_pcap_remove(struct spi_device *spi)
394 {
395 struct pcap_chip *pcap = spi_get_drvdata(spi);
396 unsigned long flags;
397 int i;
398
399 /* remove all registered subdevs */
400 device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
401
402 /* cleanup ADC */
403 spin_lock_irqsave(&pcap->adc_lock, flags);
404 for (i = 0; i < PCAP_ADC_MAXQ; i++)
405 kfree(pcap->adc_queue[i]);
406 spin_unlock_irqrestore(&pcap->adc_lock, flags);
407
408 /* cleanup irqchip */
409 for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
410 irq_set_chip_and_handler(i, NULL, NULL);
411
412 destroy_workqueue(pcap->workqueue);
413 }
414
ezx_pcap_probe(struct spi_device * spi)415 static int ezx_pcap_probe(struct spi_device *spi)
416 {
417 struct pcap_platform_data *pdata = dev_get_platdata(&spi->dev);
418 struct pcap_chip *pcap;
419 int i, adc_irq;
420 int ret = -ENODEV;
421
422 /* platform data is required */
423 if (!pdata)
424 goto ret;
425
426 pcap = devm_kzalloc(&spi->dev, sizeof(*pcap), GFP_KERNEL);
427 if (!pcap) {
428 ret = -ENOMEM;
429 goto ret;
430 }
431
432 spin_lock_init(&pcap->io_lock);
433 spin_lock_init(&pcap->adc_lock);
434 INIT_WORK(&pcap->isr_work, pcap_isr_work);
435 INIT_WORK(&pcap->msr_work, pcap_msr_work);
436 spi_set_drvdata(spi, pcap);
437
438 /* setup spi */
439 spi->bits_per_word = 32;
440 spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
441 ret = spi_setup(spi);
442 if (ret)
443 goto ret;
444
445 pcap->spi = spi;
446
447 /* setup irq */
448 pcap->irq_base = pdata->irq_base;
449 pcap->workqueue = create_singlethread_workqueue("pcapd");
450 if (!pcap->workqueue) {
451 ret = -ENOMEM;
452 dev_err(&spi->dev, "can't create pcap thread\n");
453 goto ret;
454 }
455
456 /* redirect interrupts to AP, except adcdone2 */
457 if (!(pdata->config & PCAP_SECOND_PORT))
458 ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
459 (1 << PCAP_IRQ_ADCDONE2));
460
461 /* setup irq chip */
462 for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
463 irq_set_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
464 irq_set_chip_data(i, pcap);
465 irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
466 }
467
468 /* mask/ack all PCAP interrupts */
469 ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
470 ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
471 pcap->msr = PCAP_MASK_ALL_INTERRUPT;
472
473 irq_set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
474 irq_set_chained_handler_and_data(spi->irq, pcap_irq_handler, pcap);
475 irq_set_irq_wake(spi->irq, 1);
476
477 /* ADC */
478 adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
479 PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
480
481 ret = devm_request_irq(&spi->dev, adc_irq, pcap_adc_irq, 0, "ADC",
482 pcap);
483 if (ret)
484 goto free_irqchip;
485
486 /* setup subdevs */
487 for (i = 0; i < pdata->num_subdevs; i++) {
488 ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
489 if (ret)
490 goto remove_subdevs;
491 }
492
493 /* board specific quirks */
494 if (pdata->init)
495 pdata->init(pcap);
496
497 return 0;
498
499 remove_subdevs:
500 device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
501 free_irqchip:
502 for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
503 irq_set_chip_and_handler(i, NULL, NULL);
504 /* destroy_workqueue: */
505 destroy_workqueue(pcap->workqueue);
506 ret:
507 return ret;
508 }
509
510 static struct spi_driver ezxpcap_driver = {
511 .probe = ezx_pcap_probe,
512 .remove = ezx_pcap_remove,
513 .driver = {
514 .name = "ezx-pcap",
515 },
516 };
517
ezx_pcap_init(void)518 static int __init ezx_pcap_init(void)
519 {
520 return spi_register_driver(&ezxpcap_driver);
521 }
522
ezx_pcap_exit(void)523 static void __exit ezx_pcap_exit(void)
524 {
525 spi_unregister_driver(&ezxpcap_driver);
526 }
527
528 subsys_initcall(ezx_pcap_init);
529 module_exit(ezx_pcap_exit);
530
531 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
532 MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");
533 MODULE_ALIAS("spi:ezx-pcap");
534