mfd: Add pm8xxx irq support

Add support for the irq controller in Qualcomm 8xxx pmic. The 8xxx
interrupt controller provides control for gpio and mpp configured as
interrupts in addition to other subdevice interrupts. The interrupt
controller also provides a way to read the real time status of an
interrupt. This real time status is the only way one can get the
input values of gpio and mpp lines.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/Kconfig

@@ -709,6 +709,16 @@ config MFD_PM8921_CORE
 	  Say M here if you want to include support for PM8921 chip as a module.
 	  This will build a module called "pm8921-core".
 
+config MFD_PM8XXX_IRQ
+	bool "Support for Qualcomm PM8xxx IRQ features"
+	depends on MFD_PM8XXX
+	default y if MFD_PM8XXX
+	help
+	  This is the IRQ driver for Qualcomm PM 8xxx PMIC chips.
+
+	  This is required to use certain other PM 8xxx features, such as GPIO
+	  and MPP.
+
 endif # MFD_SUPPORT
 
 menu "Multimedia Capabilities Port drivers"

drivers/mfd/Makefile

@@ -92,3 +92,4 @@ obj-$(CONFIG_MFD_WL1273_CORE)	+= wl1273-core.o
 obj-$(CONFIG_MFD_CS5535)	+= cs5535-mfd.o
 obj-$(CONFIG_MFD_OMAP_USB_HOST)	+= omap-usb-host.o
 obj-$(CONFIG_MFD_PM8921_CORE) 	+= pm8921-core.o
+obj-$(CONFIG_MFD_PM8XXX_IRQ) 	+= pm8xxx-irq.o

drivers/mfd/pm8921-core.c

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/err.h>
 #include <linux/msm_ssbi.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/pm8xxx/pm8921.h>
@@ -26,6 +27,7 @@
 
 struct pm8921 {
 	struct device			*dev;
+	struct pm_irq_chip		*irq_chip;
 };
 
 static int pm8921_readb(const struct device *dev, u16 addr, u8 *val)
@@ -62,19 +64,53 @@ static int pm8921_write_buf(const struct device *dev, u16 addr, u8 *buf,
 	return msm_ssbi_write(pmic->dev->parent, addr, buf, cnt);
 }
 
+static int pm8921_read_irq_stat(const struct device *dev, int irq)
+{
+	const struct pm8xxx_drvdata *pm8921_drvdata = dev_get_drvdata(dev);
+	const struct pm8921 *pmic = pm8921_drvdata->pm_chip_data;
+
+	return pm8xxx_get_irq_stat(pmic->irq_chip, irq);
+}
+
 static struct pm8xxx_drvdata pm8921_drvdata = {
 	.pmic_readb		= pm8921_readb,
 	.pmic_writeb		= pm8921_writeb,
 	.pmic_read_buf		= pm8921_read_buf,
 	.pmic_write_buf		= pm8921_write_buf,
+	.pmic_read_irq_stat	= pm8921_read_irq_stat,
 };
 
+static int __devinit pm8921_add_subdevices(const struct pm8921_platform_data
+					   *pdata,
+					   struct pm8921 *pmic,
+					   u32 rev)
+{
+	int ret = 0, irq_base = 0;
+	struct pm_irq_chip *irq_chip;
+
+	if (pdata->irq_pdata) {
+		pdata->irq_pdata->irq_cdata.nirqs = PM8921_NR_IRQS;
+		pdata->irq_pdata->irq_cdata.rev = rev;
+		irq_base = pdata->irq_pdata->irq_base;
+		irq_chip = pm8xxx_irq_init(pmic->dev, pdata->irq_pdata);
+
+		if (IS_ERR(irq_chip)) {
+			pr_err("Failed to init interrupts ret=%ld\n",
+					PTR_ERR(irq_chip));
+			return PTR_ERR(irq_chip);
+		}
+		pmic->irq_chip = irq_chip;
+	}
+	return ret;
+}
+
 static int __devinit pm8921_probe(struct platform_device *pdev)
 {
 	const struct pm8921_platform_data *pdata = pdev->dev.platform_data;
 	struct pm8921 *pmic;
 	int rc;
 	u8 val;
+	u32 rev;
 
 	if (!pdata) {
 		pr_err("missing platform data\n");
@@ -94,6 +130,7 @@ static int __devinit pm8921_probe(struct platform_device *pdev)
 		goto err_read_rev;
 	}
 	pr_info("PMIC revision 1: %02X\n", val);
+	rev = val;
 
 	/* Read PMIC chip revision 2 */
 	rc = msm_ssbi_read(pdev->dev.parent, REG_HWREV_2, &val, sizeof(val));
@@ -103,13 +140,26 @@ static int __devinit pm8921_probe(struct platform_device *pdev)
 		goto err_read_rev;
 	}
 	pr_info("PMIC revision 2: %02X\n", val);
+	rev |= val << BITS_PER_BYTE;
 
 	pmic->dev = &pdev->dev;
 	pm8921_drvdata.pm_chip_data = pmic;
 	platform_set_drvdata(pdev, &pm8921_drvdata);
 
+	rc = pm8921_add_subdevices(pdata, pmic, rev);
+	if (rc) {
+		pr_err("Cannot add subdevices rc=%d\n", rc);
+		goto err;
+	}
+
+	/* gpio might not work if no irq device is found */
+	WARN_ON(pmic->irq_chip == NULL);
+
 	return 0;
 
+err:
+	mfd_remove_devices(pmic->dev);
+	platform_set_drvdata(pdev, NULL);
 err_read_rev:
 	kfree(pmic);
 	return rc;
@@ -125,6 +175,10 @@ static int __devexit pm8921_remove(struct platform_device *pdev)
 		pmic = drvdata->pm_chip_data;
 	if (pmic)
 		mfd_remove_devices(pmic->dev);
+	if (pmic->irq_chip) {
+		pm8xxx_irq_exit(pmic->irq_chip);
+		pmic->irq_chip = NULL;
+	}
 	platform_set_drvdata(pdev, NULL);
 	kfree(pmic);