mfd: Add MAX8997/8966 IRQ control

This patch enables IRQ handling for MAX8997/8966 chips.

Please note that Fuel-Gauge-related IRQs are not implemented in this
initial release. The fuel gauge module in MAX8997 is identical to
MAX17042, which is already in Linux kernel. In order to use the
already-existing MAX17042 driver for fuel gauge module in MAX8997, the
main interrupt handler of MAX8997 should relay related interrupts to
MAX17042 driver. However, in order to do this, we need to modify
MAX17042 driver as well because MAX17042 driver does not have any
interrupt handlers for now. We are not going to implement this in this
initial release as it is not crucial in basic operations of MAX8997.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 378 insertions, 1 deletions

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 47f5709f382..ef489f25340 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -63,7 +63,7 @@ obj-$(CONFIG_UCB1400_CORE)	+= ucb1400_core.o
 obj-$(CONFIG_PMIC_DA903X)	+= da903x.o
 max8925-objs			:= max8925-core.o max8925-i2c.o
 obj-$(CONFIG_MFD_MAX8925)	+= max8925.o
-obj-$(CONFIG_MFD_MAX8997)	+= max8997.o
+obj-$(CONFIG_MFD_MAX8997)	+= max8997.o max8997-irq.o
 obj-$(CONFIG_MFD_MAX8998)	+= max8998.o max8998-irq.o
 
 pcf50633-objs			:= pcf50633-core.o pcf50633-irq.o
diff --git a/drivers/mfd/max8997-irq.c b/drivers/mfd/max8997-irq.c
new file mode 100644
index 00000000000..e85c874133c
--- /dev/null
+++ b/drivers/mfd/max8997-irq.c
@@ -0,0 +1,377 @@
+/*
+ * max8997-irq.c - Interrupt controller support for MAX8997
+ *
+ * Copyright (C) 2011 Samsung Electronics Co.Ltd
+ * MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This driver is based on max8998-irq.c
+ */
+
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/max8997.h>
+#include <linux/mfd/max8997-private.h>
+
+static const u8 max8997_mask_reg[] = {
+	[PMIC_INT1] = MAX8997_REG_INT1MSK,
+	[PMIC_INT2] = MAX8997_REG_INT2MSK,
+	[PMIC_INT3] = MAX8997_REG_INT3MSK,
+	[PMIC_INT4] = MAX8997_REG_INT4MSK,
+	[FUEL_GAUGE] = MAX8997_REG_INVALID,
+	[MUIC_INT1] = MAX8997_MUIC_REG_INTMASK1,
+	[MUIC_INT2] = MAX8997_MUIC_REG_INTMASK2,
+	[MUIC_INT3] = MAX8997_MUIC_REG_INTMASK3,
+	[GPIO_LOW] = MAX8997_REG_INVALID,
+	[GPIO_HI] = MAX8997_REG_INVALID,
+	[FLASH_STATUS] = MAX8997_REG_INVALID,
+};
+
+static struct i2c_client *get_i2c(struct max8997_dev *max8997,
+				enum max8997_irq_source src)
+{
+	switch (src) {
+	case PMIC_INT1 ... PMIC_INT4:
+		return max8997->i2c;
+	case FUEL_GAUGE:
+		return NULL;
+	case MUIC_INT1 ... MUIC_INT3:
+		return max8997->muic;
+	case GPIO_LOW ... GPIO_HI:
+		return max8997->i2c;
+	case FLASH_STATUS:
+		return max8997->i2c;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+struct max8997_irq_data {
+	int mask;
+	enum max8997_irq_source group;
+};
+
+#define DECLARE_IRQ(idx, _group, _mask)		\
+	[(idx)] = { .group = (_group), .mask = (_mask) }
+static const struct max8997_irq_data max8997_irqs[] = {
+	DECLARE_IRQ(MAX8997_PMICIRQ_PWRONR,	PMIC_INT1, 1 << 0),
+	DECLARE_IRQ(MAX8997_PMICIRQ_PWRONF,	PMIC_INT1, 1 << 1),
+	DECLARE_IRQ(MAX8997_PMICIRQ_PWRON1SEC,	PMIC_INT1, 1 << 3),
+	DECLARE_IRQ(MAX8997_PMICIRQ_JIGONR,	PMIC_INT1, 1 << 4),
+	DECLARE_IRQ(MAX8997_PMICIRQ_JIGONF,	PMIC_INT1, 1 << 5),
+	DECLARE_IRQ(MAX8997_PMICIRQ_LOWBAT2,	PMIC_INT1, 1 << 6),
+	DECLARE_IRQ(MAX8997_PMICIRQ_LOWBAT1,	PMIC_INT1, 1 << 7),
+
+	DECLARE_IRQ(MAX8997_PMICIRQ_JIGR,	PMIC_INT2, 1 << 0),
+	DECLARE_IRQ(MAX8997_PMICIRQ_JIGF,	PMIC_INT2, 1 << 1),
+	DECLARE_IRQ(MAX8997_PMICIRQ_MR,		PMIC_INT2, 1 << 2),
+	DECLARE_IRQ(MAX8997_PMICIRQ_DVS1OK,	PMIC_INT2, 1 << 3),
+	DECLARE_IRQ(MAX8997_PMICIRQ_DVS2OK,	PMIC_INT2, 1 << 4),
+	DECLARE_IRQ(MAX8997_PMICIRQ_DVS3OK,	PMIC_INT2, 1 << 5),
+	DECLARE_IRQ(MAX8997_PMICIRQ_DVS4OK,	PMIC_INT2, 1 << 6),
+
+	DECLARE_IRQ(MAX8997_PMICIRQ_CHGINS,	PMIC_INT3, 1 << 0),
+	DECLARE_IRQ(MAX8997_PMICIRQ_CHGRM,	PMIC_INT3, 1 << 1),
+	DECLARE_IRQ(MAX8997_PMICIRQ_DCINOVP,	PMIC_INT3, 1 << 2),
+	DECLARE_IRQ(MAX8997_PMICIRQ_TOPOFFR,	PMIC_INT3, 1 << 3),
+	DECLARE_IRQ(MAX8997_PMICIRQ_CHGRSTF,	PMIC_INT3, 1 << 5),
+	DECLARE_IRQ(MAX8997_PMICIRQ_MBCHGTMEXPD,	PMIC_INT3, 1 << 7),
+
+	DECLARE_IRQ(MAX8997_PMICIRQ_RTC60S,	PMIC_INT4, 1 << 0),
+	DECLARE_IRQ(MAX8997_PMICIRQ_RTCA1,	PMIC_INT4, 1 << 1),
+	DECLARE_IRQ(MAX8997_PMICIRQ_RTCA2,	PMIC_INT4, 1 << 2),
+	DECLARE_IRQ(MAX8997_PMICIRQ_SMPL_INT,	PMIC_INT4, 1 << 3),
+	DECLARE_IRQ(MAX8997_PMICIRQ_RTC1S,	PMIC_INT4, 1 << 4),
+	DECLARE_IRQ(MAX8997_PMICIRQ_WTSR,	PMIC_INT4, 1 << 5),
+
+	DECLARE_IRQ(MAX8997_MUICIRQ_ADCError,	MUIC_INT1, 1 << 2),
+	DECLARE_IRQ(MAX8997_MUICIRQ_ADCLow,	MUIC_INT1, 1 << 1),
+	DECLARE_IRQ(MAX8997_MUICIRQ_ADC,	MUIC_INT1, 1 << 0),
+
+	DECLARE_IRQ(MAX8997_MUICIRQ_VBVolt,	MUIC_INT2, 1 << 4),
+	DECLARE_IRQ(MAX8997_MUICIRQ_DBChg,	MUIC_INT2, 1 << 3),
+	DECLARE_IRQ(MAX8997_MUICIRQ_DCDTmr,	MUIC_INT2, 1 << 2),
+	DECLARE_IRQ(MAX8997_MUICIRQ_ChgDetRun,	MUIC_INT2, 1 << 1),
+	DECLARE_IRQ(MAX8997_MUICIRQ_ChgTyp,	MUIC_INT2, 1 << 0),
+
+	DECLARE_IRQ(MAX8997_MUICIRQ_OVP,	MUIC_INT3, 1 << 2),
+};
+
+static void max8997_irq_lock(struct irq_data *data)
+{
+	struct max8997_dev *max8997 = get_irq_chip_data(data->irq);
+
+	mutex_lock(&max8997->irqlock);
+}
+
+static void max8997_irq_sync_unlock(struct irq_data *data)
+{
+	struct max8997_dev *max8997 = get_irq_chip_data(data->irq);
+	int i;
+
+	for (i = 0; i < MAX8997_IRQ_GROUP_NR; i++) {
+		u8 mask_reg = max8997_mask_reg[i];
+		struct i2c_client *i2c = get_i2c(max8997, i);
+
+		if (mask_reg == MAX8997_REG_INVALID ||
+				IS_ERR_OR_NULL(i2c))
+			continue;
+		max8997->irq_masks_cache[i] = max8997->irq_masks_cur[i];
+
+		max8997_write_reg(i2c, max8997_mask_reg[i],
+				max8997->irq_masks_cur[i]);
+	}
+
+	mutex_unlock(&max8997->irqlock);
+}
+
+static const inline struct max8997_irq_data *
+irq_to_max8997_irq(struct max8997_dev *max8997, int irq)
+{
+	return &max8997_irqs[irq - max8997->irq_base];
+}
+
+static void max8997_irq_mask(struct irq_data *data)
+{
+	struct max8997_dev *max8997 = get_irq_chip_data(data->irq);
+	const struct max8997_irq_data *irq_data = irq_to_max8997_irq(max8997,
+								data->irq);
+
+	max8997->irq_masks_cur[irq_data->group] |= irq_data->mask;
+}
+
+static void max8997_irq_unmask(struct irq_data *data)
+{
+	struct max8997_dev *max8997 = get_irq_chip_data(data->irq);
+	const struct max8997_irq_data *irq_data = irq_to_max8997_irq(max8997,
+								data->irq);
+
+	max8997->irq_masks_cur[irq_data->group] &= ~irq_data->mask;
+}
+
+static struct irq_chip max8997_irq_chip = {
+	.name			= "max8997",
+	.irq_bus_lock		= max8997_irq_lock,
+	.irq_bus_sync_unlock	= max8997_irq_sync_unlock,
+	.irq_mask		= max8997_irq_mask,
+	.irq_unmask		= max8997_irq_unmask,
+};
+
+#define MAX8997_IRQSRC_PMIC		(1 << 1)
+#define MAX8997_IRQSRC_FUELGAUGE	(1 << 2)
+#define MAX8997_IRQSRC_MUIC		(1 << 3)
+#define MAX8997_IRQSRC_GPIO		(1 << 4)
+#define MAX8997_IRQSRC_FLASH		(1 << 5)
+static irqreturn_t max8997_irq_thread(int irq, void *data)
+{
+	struct max8997_dev *max8997 = data;
+	u8 irq_reg[MAX8997_IRQ_GROUP_NR] = {};
+	u8 irq_src;
+	int ret;
+	int i;
+
+	ret = max8997_read_reg(max8997->i2c, MAX8997_REG_INTSRC, &irq_src);
+	if (ret < 0) {
+		dev_err(max8997->dev, "Failed to read interrupt source: %d\n",
+				ret);
+		return IRQ_NONE;
+	}
+
+	if (irq_src & MAX8997_IRQSRC_PMIC) {
+		/* PMIC INT1 ~ INT4 */
+		max8997_bulk_read(max8997->i2c, MAX8997_REG_INT1, 4,
+				&irq_reg[PMIC_INT1]);
+	}
+	if (irq_src & MAX8997_IRQSRC_FUELGAUGE) {
+		/*
+		 * TODO: FUEL GAUGE
+		 *
+		 * This is to be supported by Max17042 driver. When
+		 * an interrupt incurs here, it should be relayed to a
+		 * Max17042 device that is connected (probably by
+		 * platform-data). However, we do not have interrupt
+		 * handling in Max17042 driver currently. The Max17042 IRQ
+		 * driver should be ready to be used as a stand-alone device and
+		 * a Max8997-dependent device. Because it is not ready in
+		 * Max17042-side and it is not too critical in operating
+		 * Max8997, we do not implement this in initial releases.
+		 */
+		irq_reg[FUEL_GAUGE] = 0;
+	}
+	if (irq_src & MAX8997_IRQSRC_MUIC) {
+		/* MUIC INT1 ~ INT3 */
+		max8997_bulk_read(max8997->muic, MAX8997_MUIC_REG_INT1, 3,
+				&irq_reg[MUIC_INT1]);
+	}
+	if (irq_src & MAX8997_IRQSRC_GPIO) {
+		/* GPIO Interrupt */
+		u8 gpio_info[MAX8997_NUM_GPIO];
+
+		irq_reg[GPIO_LOW] = 0;
+		irq_reg[GPIO_HI] = 0;
+
+		max8997_bulk_read(max8997->i2c, MAX8997_REG_GPIOCNTL1,
+				MAX8997_NUM_GPIO, gpio_info);
+		for (i = 0; i < MAX8997_NUM_GPIO; i++) {
+			bool interrupt = false;
+
+			switch (gpio_info[i] & MAX8997_GPIO_INT_MASK) {
+			case MAX8997_GPIO_INT_BOTH:
+				if (max8997->gpio_status[i] != gpio_info[i])
+					interrupt = true;
+				break;
+			case MAX8997_GPIO_INT_RISE:
+				if ((max8997->gpio_status[i] != gpio_info[i]) &&
+				    (gpio_info[i] & MAX8997_GPIO_DATA_MASK))
+					interrupt = true;
+				break;
+			case MAX8997_GPIO_INT_FALL:
+				if ((max8997->gpio_status[i] != gpio_info[i]) &&
+				    !(gpio_info[i] & MAX8997_GPIO_DATA_MASK))
+					interrupt = true;
+				break;
+			default:
+				break;
+			}
+
+			if (interrupt) {
+				if (i < 8)
+					irq_reg[GPIO_LOW] |= (1 << i);
+				else
+					irq_reg[GPIO_HI] |= (1 << (i - 8));
+			}
+
+		}
+	}
+	if (irq_src & MAX8997_IRQSRC_FLASH) {
+		/* Flash Status Interrupt */
+		ret = max8997_read_reg(max8997->i2c, MAX8997_REG_FLASHSTATUS,
+				&irq_reg[FLASH_STATUS]);
+	}
+
+	/* Apply masking */
+	for (i = 0; i < MAX8997_IRQ_GROUP_NR; i++)
+		irq_reg[i] &= ~max8997->irq_masks_cur[i];
+
+	/* Report */
+	for (i = 0; i < MAX8997_IRQ_NR; i++) {
+		if (irq_reg[max8997_irqs[i].group] & max8997_irqs[i].mask)
+			handle_nested_irq(max8997->irq_base + i);
+	}
+
+	return IRQ_HANDLED;
+}
+
+int max8997_irq_resume(struct max8997_dev *max8997)
+{
+	if (max8997->irq && max8997->irq_base)
+		max8997_irq_thread(max8997->irq_base, max8997);
+	return 0;
+}
+
+int max8997_irq_init(struct max8997_dev *max8997)
+{
+	int i;
+	int cur_irq;
+	int ret;
+	u8 val;
+
+	if (!max8997->irq) {
+		dev_warn(max8997->dev, "No interrupt specified.\n");
+		max8997->irq_base = 0;
+		return 0;
+	}
+
+	if (!max8997->irq_base) {
+		dev_err(max8997->dev, "No interrupt base specified.\n");
+		return 0;
+	}
+
+	mutex_init(&max8997->irqlock);
+
+	/* Mask individual interrupt sources */
+	for (i = 0; i < MAX8997_IRQ_GROUP_NR; i++) {
+		struct i2c_client *i2c;
+
+		max8997->irq_masks_cur[i] = 0xff;
+		max8997->irq_masks_cache[i] = 0xff;
+		i2c = get_i2c(max8997, i);
+
+		if (IS_ERR_OR_NULL(i2c))
+			continue;
+		if (max8997_mask_reg[i] == MAX8997_REG_INVALID)
+			continue;
+
+		max8997_write_reg(i2c, max8997_mask_reg[i], 0xff);
+	}
+
+	for (i = 0; i < MAX8997_NUM_GPIO; i++) {
+		max8997->gpio_status[i] = (max8997_read_reg(max8997->i2c,
+						MAX8997_REG_GPIOCNTL1 + i,
+						&val)
+					& MAX8997_GPIO_DATA_MASK) ?
+					true : false;
+	}
+
+	/* Register with genirq */
+	for (i = 0; i < MAX8997_IRQ_NR; i++) {
+		cur_irq = i + max8997->irq_base;
+		set_irq_chip_data(cur_irq, max8997);
+		set_irq_chip_and_handler(cur_irq, &max8997_irq_chip,
+				handle_edge_irq);
+		set_irq_nested_thread(cur_irq, 1);
+#ifdef CONFIG_ARM
+		set_irq_flags(cur_irq, IRQF_VALID);
+#else
+		set_irq_noprobe(cur_irq);
+#endif
+	}
+
+	ret = request_threaded_irq(max8997->irq, NULL, max8997_irq_thread,
+			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+			"max8997-irq", max8997);
+
+	if (ret) {
+		dev_err(max8997->dev, "Failed to request IRQ %d: %d\n",
+				max8997->irq, ret);
+		return ret;
+	}
+
+	if (!max8997->ono)
+		return 0;
+
+	ret = request_threaded_irq(max8997->ono, NULL, max8997_irq_thread,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
+			IRQF_ONESHOT, "max8997-ono", max8997);
+
+	if (ret)
+		dev_err(max8997->dev, "Failed to request ono-IRQ %d: %d\n",
+				max8997->ono, ret);
+
+	return 0;
+}
+
+void max8997_irq_exit(struct max8997_dev *max8997)
+{
+	if (max8997->ono)
+		free_irq(max8997->ono, max8997);
+
+	if (max8997->irq)
+		free_irq(max8997->irq, max8997);
+}