mfd: add PCAP driver

The PCAP Asic as present on EZX phones is a multi function device with
voltage regulators, ADC, touch screen controller, RTC, USB transceiver,
leds controller, and audio codec.

It has two SPI ports, typically one is connected to the application
processor and another to the baseband, this driver provides read/write
functions to its registers, irq demultiplexer and ADC
queueing/abstraction.

This chip is used on a lot of Motorola phones, it was manufactured by TI
as a custom product with the name PTWL93017, later this design evolved
into the ATLAS PMIC from Freescale (MC13783).

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 514 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 61f0346..287d47b 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -255,6 +255,13 @@ config AB3100_CORE
 	  LEDs, vibrator, system power and temperature, power management
 	  and ALSA sound.
 
+config EZX_PCAP
+	bool "PCAP Support"
+	depends on GENERIC_HARDIRQS && SPI_MASTER
+	help
+	  This enables the PCAP ASIC present on EZX Phones. This is
+	  needed for MMC, TouchScreen, Sound, USB, etc..
+
 endmenu
 
 menu "Multimedia Capabilities Port drivers"
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f5f3371..6f8a9a1af 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -26,6 +26,8 @@ obj-$(CONFIG_TWL4030_CORE)	+= twl4030-core.o twl4030-irq.o
 
 obj-$(CONFIG_MFD_CORE)		+= mfd-core.o
 
+obj-$(CONFIG_EZX_PCAP)		+= ezx-pcap.o
+
 obj-$(CONFIG_MCP)		+= mcp-core.o
 obj-$(CONFIG_MCP_SA11X0)	+= mcp-sa11x0.o
 obj-$(CONFIG_MCP_UCB1200)	+= ucb1x00-core.o
diff --git a/drivers/mfd/ezx-pcap.c b/drivers/mfd/ezx-pcap.c
new file mode 100644
index 0000000..671a7ef
--- /dev/null
+++ b/drivers/mfd/ezx-pcap.c
@@ -0,0 +1,505 @@
+/*
+ * Driver for Motorola PCAP2 as present in EZX phones
+ *
+ * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
+ * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/mfd/ezx-pcap.h>
+#include <linux/spi/spi.h>
+
+#define PCAP_ADC_MAXQ		8
+struct pcap_adc_request {
+	u8 bank;
+	u8 ch[2];
+	u32 flags;
+	void (*callback)(void *, u16[]);
+	void *data;
+};
+
+struct pcap_adc_sync_request {
+	u16 res[2];
+	struct completion completion;
+};
+
+struct pcap_chip {
+	struct spi_device *spi;
+
+	/* IO */
+	u32 buf;
+	struct mutex io_mutex;
+
+	/* IRQ */
+	unsigned int irq_base;
+	u32 msr;
+	struct work_struct isr_work;
+	struct work_struct msr_work;
+	struct workqueue_struct *workqueue;
+
+	/* ADC */
+	struct pcap_adc_request *adc_queue[PCAP_ADC_MAXQ];
+	u8 adc_head;
+	u8 adc_tail;
+	struct mutex adc_mutex;
+};
+
+/* IO */
+static int ezx_pcap_putget(struct pcap_chip *pcap, u32 *data)
+{
+	struct spi_transfer t;
+	struct spi_message m;
+	int status;
+
+	memset(&t, 0, sizeof t);
+	spi_message_init(&m);
+	t.len = sizeof(u32);
+	spi_message_add_tail(&t, &m);
+
+	pcap->buf = *data;
+	t.tx_buf = (u8 *) &pcap->buf;
+	t.rx_buf = (u8 *) &pcap->buf;
+	status = spi_sync(pcap->spi, &m);
+
+	if (status == 0)
+		*data = pcap->buf;
+
+	return status;
+}
+
+int ezx_pcap_write(struct pcap_chip *pcap, u8 reg_num, u32 value)
+{
+	int ret;
+
+	mutex_lock(&pcap->io_mutex);
+	value &= PCAP_REGISTER_VALUE_MASK;
+	value |= PCAP_REGISTER_WRITE_OP_BIT
+		| (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
+	ret = ezx_pcap_putget(pcap, &value);
+	mutex_unlock(&pcap->io_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ezx_pcap_write);
+
+int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
+{
+	int ret;
+
+	mutex_lock(&pcap->io_mutex);
+	*value = PCAP_REGISTER_READ_OP_BIT
+		| (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
+
+	ret = ezx_pcap_putget(pcap, value);
+	mutex_unlock(&pcap->io_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ezx_pcap_read);
+
+/* IRQ */
+static inline unsigned int irq2pcap(struct pcap_chip *pcap, int irq)
+{
+	return 1 << (irq - pcap->irq_base);
+}
+
+int pcap_to_irq(struct pcap_chip *pcap, int irq)
+{
+	return pcap->irq_base + irq;
+}
+EXPORT_SYMBOL_GPL(pcap_to_irq);
+
+static void pcap_mask_irq(unsigned int irq)
+{
+	struct pcap_chip *pcap = get_irq_chip_data(irq);
+
+	pcap->msr |= irq2pcap(pcap, irq);
+	queue_work(pcap->workqueue, &pcap->msr_work);
+}
+
+static void pcap_unmask_irq(unsigned int irq)
+{
+	struct pcap_chip *pcap = get_irq_chip_data(irq);
+
+	pcap->msr &= ~irq2pcap(pcap, irq);
+	queue_work(pcap->workqueue, &pcap->msr_work);
+}
+
+static struct irq_chip pcap_irq_chip = {
+	.name	= "pcap",
+	.mask	= pcap_mask_irq,
+	.unmask	= pcap_unmask_irq,
+};
+
+static void pcap_msr_work(struct work_struct *work)
+{
+	struct pcap_chip *pcap = container_of(work, struct pcap_chip, msr_work);
+
+	ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
+}
+
+static void pcap_isr_work(struct work_struct *work)
+{
+	struct pcap_chip *pcap = container_of(work, struct pcap_chip, isr_work);
+	struct pcap_platform_data *pdata = pcap->spi->dev.platform_data;
+	u32 msr, isr, int_sel, service;
+	int irq;
+
+	ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
+	ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
+
+	/* We cant service/ack irqs that are assigned to port 2 */
+	if (!(pdata->config & PCAP_SECOND_PORT)) {
+		ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
+		isr &= ~int_sel;
+	}
+	ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
+
+	local_irq_disable();
+	service = isr & ~msr;
+
+	for (irq = pcap->irq_base; service; service >>= 1, irq++) {
+		if (service & 1) {
+			struct irq_desc *desc = irq_to_desc(irq);
+
+			if (WARN(!desc, KERN_WARNING
+					"Invalid PCAP IRQ %d\n", irq))
+				break;
+
+			if (desc->status & IRQ_DISABLED)
+				note_interrupt(irq, desc, IRQ_NONE);
+			else
+				desc->handle_irq(irq, desc);
+		}
+	}
+	local_irq_enable();
+}
+
+static void pcap_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct pcap_chip *pcap = get_irq_data(irq);
+
+	desc->chip->ack(irq);
+	queue_work(pcap->workqueue, &pcap->isr_work);
+	return;
+}
+
+/* ADC */
+static void pcap_disable_adc(struct pcap_chip *pcap)
+{
+	u32 tmp;
+
+	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
+	tmp &= ~(PCAP_ADC_ADEN|PCAP_ADC_BATT_I_ADC|PCAP_ADC_BATT_I_POLARITY);
+	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
+}
+
+static void pcap_adc_trigger(struct pcap_chip *pcap)
+{
+	u32 tmp;
+	u8 head;
+
+	mutex_lock(&pcap->adc_mutex);
+	head = pcap->adc_head;
+	if (!pcap->adc_queue[head]) {
+		/* queue is empty, save power */
+		pcap_disable_adc(pcap);
+		mutex_unlock(&pcap->adc_mutex);
+		return;
+	}
+	mutex_unlock(&pcap->adc_mutex);
+
+	/* start conversion on requested bank */
+	tmp = pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
+
+	if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
+		tmp |= PCAP_ADC_AD_SEL1;
+
+	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
+	ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
+}
+
+static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
+{
+	struct pcap_chip *pcap = _pcap;
+	struct pcap_adc_request *req;
+	u16 res[2];
+	u32 tmp;
+
+	mutex_lock(&pcap->adc_mutex);
+	req = pcap->adc_queue[pcap->adc_head];
+
+	if (WARN(!req, KERN_WARNING "adc irq without pending request\n"))
+		return IRQ_HANDLED;
+
+	/* read requested channels results */
+	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
+	tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
+	tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
+	tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
+	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
+	ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
+	res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
+	res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
+
+	pcap->adc_queue[pcap->adc_head] = NULL;
+	pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
+	mutex_unlock(&pcap->adc_mutex);
+
+	/* pass the results and release memory */
+	req->callback(req->data, res);
+	kfree(req);
+
+	/* trigger next conversion (if any) on queue */
+	pcap_adc_trigger(pcap);
+
+	return IRQ_HANDLED;
+}
+
+int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
+						void *callback, void *data)
+{
+	struct pcap_adc_request *req;
+
+	/* This will be freed after we have a result */
+	req = kmalloc(sizeof(struct pcap_adc_request), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	req->bank = bank;
+	req->flags = flags;
+	req->ch[0] = ch[0];
+	req->ch[1] = ch[1];
+	req->callback = callback;
+	req->data = data;
+
+	mutex_lock(&pcap->adc_mutex);
+	if (pcap->adc_queue[pcap->adc_tail]) {
+		mutex_unlock(&pcap->adc_mutex);
+		kfree(req);
+		return -EBUSY;
+	}
+	pcap->adc_queue[pcap->adc_tail] = req;
+	pcap->adc_tail = (pcap->adc_tail + 1) & (PCAP_ADC_MAXQ - 1);
+	mutex_unlock(&pcap->adc_mutex);
+
+	/* start conversion */
+	pcap_adc_trigger(pcap);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pcap_adc_async);
+
+static void pcap_adc_sync_cb(void *param, u16 res[])
+{
+	struct pcap_adc_sync_request *req = param;
+
+	req->res[0] = res[0];
+	req->res[1] = res[1];
+	complete(&req->completion);
+}
+
+int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
+								u16 res[])
+{
+	struct pcap_adc_sync_request sync_data;
+	int ret;
+
+	init_completion(&sync_data.completion);
+	ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
+								&sync_data);
+	if (ret)
+		return ret;
+	wait_for_completion(&sync_data.completion);
+	res[0] = sync_data.res[0];
+	res[1] = sync_data.res[1];
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pcap_adc_sync);
+
+/* subdevs */
+static int pcap_remove_subdev(struct device *dev, void *unused)
+{
+	platform_device_unregister(to_platform_device(dev));
+	return 0;
+}
+
+static int __devinit pcap_add_subdev(struct pcap_chip *pcap,
+						struct pcap_subdev *subdev)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_alloc(subdev->name, subdev->id);
+	pdev->dev.parent = &pcap->spi->dev;
+	pdev->dev.platform_data = subdev->platform_data;
+	platform_set_drvdata(pdev, pcap);
+
+	return platform_device_add(pdev);
+}
+
+static int __devexit ezx_pcap_remove(struct spi_device *spi)
+{
+	struct pcap_chip *pcap = dev_get_drvdata(&spi->dev);
+	struct pcap_platform_data *pdata = spi->dev.platform_data;
+	int i, adc_irq;
+
+	/* remove all registered subdevs */
+	device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
+
+	/* cleanup ADC */
+	adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
+				PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
+	free_irq(adc_irq, pcap);
+	mutex_lock(&pcap->adc_mutex);
+	for (i = 0; i < PCAP_ADC_MAXQ; i++)
+		kfree(pcap->adc_queue[i]);
+	mutex_unlock(&pcap->adc_mutex);
+
+	/* cleanup irqchip */
+	for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
+		set_irq_chip_and_handler(i, NULL, NULL);
+
+	destroy_workqueue(pcap->workqueue);
+
+	kfree(pcap);
+
+	return 0;
+}
+
+static int __devinit ezx_pcap_probe(struct spi_device *spi)
+{
+	struct pcap_platform_data *pdata = spi->dev.platform_data;
+	struct pcap_chip *pcap;
+	int i, adc_irq;
+	int ret = -ENODEV;
+
+	/* platform data is required */
+	if (!pdata)
+		goto ret;
+
+	pcap = kzalloc(sizeof(*pcap), GFP_KERNEL);
+	if (!pcap) {
+		ret = -ENOMEM;
+		goto ret;
+	}
+
+	mutex_init(&pcap->io_mutex);
+	mutex_init(&pcap->adc_mutex);
+	INIT_WORK(&pcap->isr_work, pcap_isr_work);
+	INIT_WORK(&pcap->msr_work, pcap_msr_work);
+	dev_set_drvdata(&spi->dev, pcap);
+
+	/* setup spi */
+	spi->bits_per_word = 32;
+	spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
+	ret = spi_setup(spi);
+	if (ret)
+		goto free_pcap;
+
+	pcap->spi = spi;
+
+	/* setup irq */
+	pcap->irq_base = pdata->irq_base;
+	pcap->workqueue = create_singlethread_workqueue("pcapd");
+	if (!pcap->workqueue) {
+		dev_err(&spi->dev, "cant create pcap thread\n");
+		goto free_pcap;
+	}
+
+	/* redirect interrupts to AP, except adcdone2 */
+	if (!(pdata->config & PCAP_SECOND_PORT))
+		ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
+					(1 << PCAP_IRQ_ADCDONE2));
+
+	/* setup irq chip */
+	for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
+		set_irq_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
+		set_irq_chip_data(i, pcap);
+#ifdef CONFIG_ARM
+		set_irq_flags(i, IRQF_VALID);
+#else
+		set_irq_noprobe(i);
+#endif
+	}
+
+	/* mask/ack all PCAP interrupts */
+	ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
+	ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
+	pcap->msr = PCAP_MASK_ALL_INTERRUPT;
+
+	set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
+	set_irq_data(spi->irq, pcap);
+	set_irq_chained_handler(spi->irq, pcap_irq_handler);
+	set_irq_wake(spi->irq, 1);
+
+	/* ADC */
+	adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
+					PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
+
+	ret = request_irq(adc_irq, pcap_adc_irq, 0, "ADC", pcap);
+	if (ret)
+		goto free_irqchip;
+
+	/* setup subdevs */
+	for (i = 0; i < pdata->num_subdevs; i++) {
+		ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
+		if (ret)
+			goto remove_subdevs;
+	}
+
+	/* board specific quirks */
+	if (pdata->init)
+		pdata->init(pcap);
+
+	return 0;
+
+remove_subdevs:
+	device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
+/* free_adc: */
+	free_irq(adc_irq, pcap);
+free_irqchip:
+	for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
+		set_irq_chip_and_handler(i, NULL, NULL);
+/* destroy_workqueue: */
+	destroy_workqueue(pcap->workqueue);
+free_pcap:
+	kfree(pcap);
+ret:
+	return ret;
+}
+
+static struct spi_driver ezxpcap_driver = {
+	.probe	= ezx_pcap_probe,
+	.remove = __devexit_p(ezx_pcap_remove),
+	.driver = {
+		.name	= "ezx-pcap",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init ezx_pcap_init(void)
+{
+	return spi_register_driver(&ezxpcap_driver);
+}
+
+static void __exit ezx_pcap_exit(void)
+{
+	spi_unregister_driver(&ezxpcap_driver);
+}
+
+module_init(ezx_pcap_init);
+module_exit(ezx_pcap_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
+MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");