1/*
2 * Driver for Motorola PCAP2 as present in EZX phones
3 *
4 * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
5 * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/platform_device.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/mfd/ezx-pcap.h>
19#include <linux/spi/spi.h>
20#include <linux/gpio.h>
21#include <linux/slab.h>
22
23#define PCAP_ADC_MAXQ		8
24struct pcap_adc_request {
25	u8 bank;
26	u8 ch[2];
27	u32 flags;
28	void (*callback)(void *, u16[]);
29	void *data;
30};
31
32struct pcap_adc_sync_request {
33	u16 res[2];
34	struct completion completion;
35};
36
37struct pcap_chip {
38	struct spi_device *spi;
39
40	/* IO */
41	u32 buf;
42	struct mutex io_mutex;
43
44	/* IRQ */
45	unsigned int irq_base;
46	u32 msr;
47	struct work_struct isr_work;
48	struct work_struct msr_work;
49	struct workqueue_struct *workqueue;
50
51	/* ADC */
52	struct pcap_adc_request *adc_queue[PCAP_ADC_MAXQ];
53	u8 adc_head;
54	u8 adc_tail;
55	struct mutex adc_mutex;
56};
57
58/* IO */
59static int ezx_pcap_putget(struct pcap_chip *pcap, u32 *data)
60{
61	struct spi_transfer t;
62	struct spi_message m;
63	int status;
64
65	memset(&t, 0, sizeof(t));
66	spi_message_init(&m);
67	t.len = sizeof(u32);
68	spi_message_add_tail(&t, &m);
69
70	pcap->buf = *data;
71	t.tx_buf = (u8 *) &pcap->buf;
72	t.rx_buf = (u8 *) &pcap->buf;
73	status = spi_sync(pcap->spi, &m);
74
75	if (status == 0)
76		*data = pcap->buf;
77
78	return status;
79}
80
81int ezx_pcap_write(struct pcap_chip *pcap, u8 reg_num, u32 value)
82{
83	int ret;
84
85	mutex_lock(&pcap->io_mutex);
86	value &= PCAP_REGISTER_VALUE_MASK;
87	value |= PCAP_REGISTER_WRITE_OP_BIT
88		| (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
89	ret = ezx_pcap_putget(pcap, &value);
90	mutex_unlock(&pcap->io_mutex);
91
92	return ret;
93}
94EXPORT_SYMBOL_GPL(ezx_pcap_write);
95
96int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
97{
98	int ret;
99
100	mutex_lock(&pcap->io_mutex);
101	*value = PCAP_REGISTER_READ_OP_BIT
102		| (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
103
104	ret = ezx_pcap_putget(pcap, value);
105	mutex_unlock(&pcap->io_mutex);
106
107	return ret;
108}
109EXPORT_SYMBOL_GPL(ezx_pcap_read);
110
111int ezx_pcap_set_bits(struct pcap_chip *pcap, u8 reg_num, u32 mask, u32 val)
112{
113	int ret;
114	u32 tmp = PCAP_REGISTER_READ_OP_BIT |
115		(reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
116
117	mutex_lock(&pcap->io_mutex);
118	ret = ezx_pcap_putget(pcap, &tmp);
119	if (ret)
120		goto out_unlock;
121
122	tmp &= (PCAP_REGISTER_VALUE_MASK & ~mask);
123	tmp |= (val & mask) | PCAP_REGISTER_WRITE_OP_BIT |
124		(reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
125
126	ret = ezx_pcap_putget(pcap, &tmp);
127out_unlock:
128	mutex_unlock(&pcap->io_mutex);
129
130	return ret;
131}
132EXPORT_SYMBOL_GPL(ezx_pcap_set_bits);
133
134/* IRQ */
135int irq_to_pcap(struct pcap_chip *pcap, int irq)
136{
137	return irq - pcap->irq_base;
138}
139EXPORT_SYMBOL_GPL(irq_to_pcap);
140
141int pcap_to_irq(struct pcap_chip *pcap, int irq)
142{
143	return pcap->irq_base + irq;
144}
145EXPORT_SYMBOL_GPL(pcap_to_irq);
146
147static void pcap_mask_irq(struct irq_data *d)
148{
149	struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
150
151	pcap->msr |= 1 << irq_to_pcap(pcap, d->irq);
152	queue_work(pcap->workqueue, &pcap->msr_work);
153}
154
155static void pcap_unmask_irq(struct irq_data *d)
156{
157	struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
158
159	pcap->msr &= ~(1 << irq_to_pcap(pcap, d->irq));
160	queue_work(pcap->workqueue, &pcap->msr_work);
161}
162
163static struct irq_chip pcap_irq_chip = {
164	.name		= "pcap",
165	.irq_disable	= pcap_mask_irq,
166	.irq_mask	= pcap_mask_irq,
167	.irq_unmask	= pcap_unmask_irq,
168};
169
170static void pcap_msr_work(struct work_struct *work)
171{
172	struct pcap_chip *pcap = container_of(work, struct pcap_chip, msr_work);
173
174	ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
175}
176
177static void pcap_isr_work(struct work_struct *work)
178{
179	struct pcap_chip *pcap = container_of(work, struct pcap_chip, isr_work);
180	struct pcap_platform_data *pdata = dev_get_platdata(&pcap->spi->dev);
181	u32 msr, isr, int_sel, service;
182	int irq;
183
184	do {
185		ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
186		ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
187
188		/* We can't service/ack irqs that are assigned to port 2 */
189		if (!(pdata->config & PCAP_SECOND_PORT)) {
190			ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
191			isr &= ~int_sel;
192		}
193
194		ezx_pcap_write(pcap, PCAP_REG_MSR, isr | msr);
195		ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
196
197		local_irq_disable();
198		service = isr & ~msr;
199		for (irq = pcap->irq_base; service; service >>= 1, irq++) {
200			if (service & 1)
201				generic_handle_irq(irq);
202		}
203		local_irq_enable();
204		ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
205	} while (gpio_get_value(pdata->gpio));
206}
207
208static void pcap_irq_handler(unsigned int irq, struct irq_desc *desc)
209{
210	struct pcap_chip *pcap = irq_get_handler_data(irq);
211
212	desc->irq_data.chip->irq_ack(&desc->irq_data);
213	queue_work(pcap->workqueue, &pcap->isr_work);
214}
215
216/* ADC */
217void pcap_set_ts_bits(struct pcap_chip *pcap, u32 bits)
218{
219	u32 tmp;
220
221	mutex_lock(&pcap->adc_mutex);
222	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
223	tmp &= ~(PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
224	tmp |= bits & (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
225	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
226	mutex_unlock(&pcap->adc_mutex);
227}
228EXPORT_SYMBOL_GPL(pcap_set_ts_bits);
229
230static void pcap_disable_adc(struct pcap_chip *pcap)
231{
232	u32 tmp;
233
234	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
235	tmp &= ~(PCAP_ADC_ADEN|PCAP_ADC_BATT_I_ADC|PCAP_ADC_BATT_I_POLARITY);
236	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
237}
238
239static void pcap_adc_trigger(struct pcap_chip *pcap)
240{
241	u32 tmp;
242	u8 head;
243
244	mutex_lock(&pcap->adc_mutex);
245	head = pcap->adc_head;
246	if (!pcap->adc_queue[head]) {
247		/* queue is empty, save power */
248		pcap_disable_adc(pcap);
249		mutex_unlock(&pcap->adc_mutex);
250		return;
251	}
252	/* start conversion on requested bank, save TS_M bits */
253	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
254	tmp &= (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
255	tmp |= pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
256
257	if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
258		tmp |= PCAP_ADC_AD_SEL1;
259
260	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
261	mutex_unlock(&pcap->adc_mutex);
262	ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
263}
264
265static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
266{
267	struct pcap_chip *pcap = _pcap;
268	struct pcap_adc_request *req;
269	u16 res[2];
270	u32 tmp;
271
272	mutex_lock(&pcap->adc_mutex);
273	req = pcap->adc_queue[pcap->adc_head];
274
275	if (WARN(!req, "adc irq without pending request\n")) {
276		mutex_unlock(&pcap->adc_mutex);
277		return IRQ_HANDLED;
278	}
279
280	/* read requested channels results */
281	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
282	tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
283	tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
284	tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
285	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
286	ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
287	res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
288	res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
289
290	pcap->adc_queue[pcap->adc_head] = NULL;
291	pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
292	mutex_unlock(&pcap->adc_mutex);
293
294	/* pass the results and release memory */
295	req->callback(req->data, res);
296	kfree(req);
297
298	/* trigger next conversion (if any) on queue */
299	pcap_adc_trigger(pcap);
300
301	return IRQ_HANDLED;
302}
303
304int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
305						void *callback, void *data)
306{
307	struct pcap_adc_request *req;
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	mutex_lock(&pcap->adc_mutex);
322	if (pcap->adc_queue[pcap->adc_tail]) {
323		mutex_unlock(&pcap->adc_mutex);
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	mutex_unlock(&pcap->adc_mutex);
330
331	/* start conversion */
332	pcap_adc_trigger(pcap);
333
334	return 0;
335}
336EXPORT_SYMBOL_GPL(pcap_adc_async);
337
338static 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
347int 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}
364EXPORT_SYMBOL_GPL(pcap_adc_sync);
365
366/* subdevs */
367static int pcap_remove_subdev(struct device *dev, void *unused)
368{
369	platform_device_unregister(to_platform_device(dev));
370	return 0;
371}
372
373static 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
393static int ezx_pcap_remove(struct spi_device *spi)
394{
395	struct pcap_chip *pcap = spi_get_drvdata(spi);
396	int i;
397
398	/* remove all registered subdevs */
399	device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
400
401	/* cleanup ADC */
402	mutex_lock(&pcap->adc_mutex);
403	for (i = 0; i < PCAP_ADC_MAXQ; i++)
404		kfree(pcap->adc_queue[i]);
405	mutex_unlock(&pcap->adc_mutex);
406
407	/* cleanup irqchip */
408	for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
409		irq_set_chip_and_handler(i, NULL, NULL);
410
411	destroy_workqueue(pcap->workqueue);
412
413	return 0;
414}
415
416static int ezx_pcap_probe(struct spi_device *spi)
417{
418	struct pcap_platform_data *pdata = dev_get_platdata(&spi->dev);
419	struct pcap_chip *pcap;
420	int i, adc_irq;
421	int ret = -ENODEV;
422
423	/* platform data is required */
424	if (!pdata)
425		goto ret;
426
427	pcap = devm_kzalloc(&spi->dev, sizeof(*pcap), GFP_KERNEL);
428	if (!pcap) {
429		ret = -ENOMEM;
430		goto ret;
431	}
432
433	mutex_init(&pcap->io_mutex);
434	mutex_init(&pcap->adc_mutex);
435	INIT_WORK(&pcap->isr_work, pcap_isr_work);
436	INIT_WORK(&pcap->msr_work, pcap_msr_work);
437	spi_set_drvdata(spi, pcap);
438
439	/* setup spi */
440	spi->bits_per_word = 32;
441	spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
442	ret = spi_setup(spi);
443	if (ret)
444		goto ret;
445
446	pcap->spi = spi;
447
448	/* setup irq */
449	pcap->irq_base = pdata->irq_base;
450	pcap->workqueue = create_singlethread_workqueue("pcapd");
451	if (!pcap->workqueue) {
452		ret = -ENOMEM;
453		dev_err(&spi->dev, "can't create pcap thread\n");
454		goto ret;
455	}
456
457	/* redirect interrupts to AP, except adcdone2 */
458	if (!(pdata->config & PCAP_SECOND_PORT))
459		ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
460					(1 << PCAP_IRQ_ADCDONE2));
461
462	/* setup irq chip */
463	for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
464		irq_set_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
465		irq_set_chip_data(i, pcap);
466#ifdef CONFIG_ARM
467		set_irq_flags(i, IRQF_VALID);
468#else
469		irq_set_noprobe(i);
470#endif
471	}
472
473	/* mask/ack all PCAP interrupts */
474	ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
475	ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
476	pcap->msr = PCAP_MASK_ALL_INTERRUPT;
477
478	irq_set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
479	irq_set_handler_data(spi->irq, pcap);
480	irq_set_chained_handler(spi->irq, pcap_irq_handler);
481	irq_set_irq_wake(spi->irq, 1);
482
483	/* ADC */
484	adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
485					PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
486
487	ret = devm_request_irq(&spi->dev, adc_irq, pcap_adc_irq, 0, "ADC",
488				pcap);
489	if (ret)
490		goto free_irqchip;
491
492	/* setup subdevs */
493	for (i = 0; i < pdata->num_subdevs; i++) {
494		ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
495		if (ret)
496			goto remove_subdevs;
497	}
498
499	/* board specific quirks */
500	if (pdata->init)
501		pdata->init(pcap);
502
503	return 0;
504
505remove_subdevs:
506	device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
507free_irqchip:
508	for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
509		irq_set_chip_and_handler(i, NULL, NULL);
510/* destroy_workqueue: */
511	destroy_workqueue(pcap->workqueue);
512ret:
513	return ret;
514}
515
516static struct spi_driver ezxpcap_driver = {
517	.probe	= ezx_pcap_probe,
518	.remove = ezx_pcap_remove,
519	.driver = {
520		.name	= "ezx-pcap",
521		.owner	= THIS_MODULE,
522	},
523};
524
525static int __init ezx_pcap_init(void)
526{
527	return spi_register_driver(&ezxpcap_driver);
528}
529
530static void __exit ezx_pcap_exit(void)
531{
532	spi_unregister_driver(&ezxpcap_driver);
533}
534
535subsys_initcall(ezx_pcap_init);
536module_exit(ezx_pcap_exit);
537
538MODULE_LICENSE("GPL");
539MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
540MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");
541MODULE_ALIAS("spi:ezx-pcap");
542