TPS65910: IRQ: Add interrupt controller

This module controls the interrupt handling for the tps chip. The
interrupt sources are the following:

- GPIO falling/rising edge detection
- Battery voltage below/above threshold
- PWRON signal
- PWRHOLD signal
- Temperature detection
- RTC alarm and periodic event

Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

3 files changed, 200 insertions, 1 deletions

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index c64fa8d48f45..bdb8eab5668b 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -93,4 +93,4 @@ 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
-obj-$(CONFIG_MFD_TPS65910)      += tps65910.o tps65910-gpio.o
+obj-$(CONFIG_MFD_TPS65910)      += tps65910.o tps65910-gpio.o tps65910-irq.o
diff --git a/drivers/mfd/tps65910-irq.c b/drivers/mfd/tps65910-irq.c
new file mode 100644
index 000000000000..b8435e045f81
--- /dev/null
+++ b/drivers/mfd/tps65910-irq.c
@@ -0,0 +1,187 @@
+/*
+ * tps65910-irq.c  --  TI TPS6591x
+ *
+ * Copyright 2010 Texas Instruments Inc.
+ *
+ * Author: Graeme Gregory <gg@slimlogic.co.uk>
+ * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
+ *
+ *  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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bug.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/mfd/tps65910.h>
+
+static inline int irq_to_tps65910_irq(struct tps65910 *tps65910,
+                                                        int irq)
+{
+        return (irq - tps65910->irq_base);
+}
+
+/*
+ * This is a threaded IRQ handler so can access I2C/SPI.  Since all
+ * interrupts are clear on read the IRQ line will be reasserted and
+ * the physical IRQ will be handled again if another interrupt is
+ * asserted while we run - in the normal course of events this is a
+ * rare occurrence so we save I2C/SPI reads.  We're also assuming that
+ * it's rare to get lots of interrupts firing simultaneously so try to
+ * minimise I/O.
+ */
+static irqreturn_t tps65910_irq(int irq, void *irq_data)
+{
+        struct tps65910 *tps65910 = irq_data;
+        u16 irq_sts;
+        u16 irq_mask;
+        u8 reg;
+        int i;
+
+        tps65910->read(tps65910, TPS65910_INT_STS, 1, &reg);
+        irq_sts = reg;
+        tps65910->read(tps65910, TPS65910_INT_STS2, 1, &reg);
+        irq_sts |= reg << 8;
+
+        tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
+        irq_mask = reg;
+        tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
+        irq_mask |= reg << 8;
+
+        irq_sts &= ~irq_mask;
+
+        if (!irq_sts)
+                return IRQ_NONE;
+
+        for (i = 0; i < TPS65910_NUM_IRQ; i++) {
+
+                if (!(irq_sts & (1 << i)))
+                        continue;
+
+                handle_nested_irq(tps65910->irq_base + i);
+        }
+
+        /* Write the STS register back to clear IRQs we handled */
+        reg = irq_sts & 0xFF;
+        tps65910->write(tps65910, TPS65910_INT_STS, 1, &reg);
+        reg = irq_sts >> 8;
+        tps65910->write(tps65910, TPS65910_INT_STS2, 1, &reg);
+
+        return IRQ_HANDLED;
+}
+
+static void tps65910_irq_lock(struct irq_data *data)
+{
+        struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
+
+        mutex_lock(&tps65910->irq_lock);
+}
+
+static void tps65910_irq_sync_unlock(struct irq_data *data)
+{
+        struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
+        u16 reg_mask;
+        u8 reg;
+
+        tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
+        reg_mask = reg;
+        tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
+        reg_mask |= reg << 8;
+
+        if (tps65910->irq_mask != reg_mask) {
+                reg = tps65910->irq_mask & 0xFF;
+                tps65910->write(tps65910, TPS65910_INT_MSK, 1, &reg);
+                reg = tps65910->irq_mask >> 8;
+                tps65910->write(tps65910, TPS65910_INT_MSK2, 1, &reg);
+        }
+        mutex_unlock(&tps65910->irq_lock);
+}
+
+static void tps65910_irq_enable(struct irq_data *data)
+{
+        struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
+
+        tps65910->irq_mask &= ~( 1 << irq_to_tps65910_irq(tps65910, data->irq));
+}
+
+static void tps65910_irq_disable(struct irq_data *data)
+{
+        struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
+
+        tps65910->irq_mask |= ( 1 << irq_to_tps65910_irq(tps65910, data->irq));
+}
+
+static struct irq_chip tps65910_irq_chip = {
+        .name = "tps65910",
+        .irq_bus_lock = tps65910_irq_lock,
+        .irq_bus_sync_unlock = tps65910_irq_sync_unlock,
+        .irq_disable = tps65910_irq_disable,
+        .irq_enable = tps65910_irq_enable,
+};
+
+int tps65910_irq_init(struct tps65910 *tps65910, int irq,
+                    struct tps65910_platform_data *pdata)
+{
+        int ret, cur_irq;
+        int flags = IRQF_ONESHOT;
+        u8 reg;
+
+        if (!irq) {
+                dev_warn(tps65910->dev, "No interrupt support, no core IRQ\n");
+                return -EINVAL;
+        }
+
+        if (!pdata || !pdata->irq_base) {
+                dev_warn(tps65910->dev, "No interrupt support, no IRQ base\n");
+                return -EINVAL;
+        }
+
+        /* Mask top level interrupts */
+        reg = 0xFF;
+        tps65910->write(tps65910, TPS65910_INT_MSK, 1, &reg);
+        reg = 0x03;
+        tps65910->write(tps65910, TPS65910_INT_MSK2, 1, &reg);
+
+        mutex_init(&tps65910->irq_lock);
+        tps65910->chip_irq = irq;
+        tps65910->irq_base = pdata->irq_base;
+
+        /* Register with genirq */
+        for (cur_irq = tps65910->irq_base;
+             cur_irq < TPS65910_NUM_IRQ + tps65910->irq_base;
+             cur_irq++) {
+                irq_set_chip_data(cur_irq, tps65910);
+                irq_set_chip_and_handler(cur_irq, &tps65910_irq_chip,
+                                         handle_edge_irq);
+                irq_set_nested_thread(cur_irq, 1);
+
+                /* ARM needs us to explicitly flag the IRQ as valid
+                 * and will set them noprobe when we do so. */
+#ifdef CONFIG_ARM
+                set_irq_flags(cur_irq, IRQF_VALID);
+#else
+                irq_set_noprobe(cur_irq);
+#endif
+        }
+
+        ret = request_threaded_irq(irq, NULL, tps65910_irq, flags,
+                                   "tps65910", tps65910);
+        if (ret != 0)
+                dev_err(tps65910->dev, "Failed to request IRQ: %d\n", ret);
+
+        return ret;
+}
+
+int tps65910_irq_exit(struct tps65910 *tps65910)
+{
+        free_irq(tps65910->chip_irq, tps65910);
+        return 0;
+}
diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
index 5a6a7be1f8cf..bf649cf6a0ae 100644
--- a/drivers/mfd/tps65910.c
+++ b/drivers/mfd/tps65910.c
@@ -136,12 +136,20 @@ static int tps65910_i2c_probe(struct i2c_client *i2c,
 {
         struct tps65910 *tps65910;
         struct tps65910_board *pmic_plat_data;
+        struct tps65910_platform_data *init_data;
         int ret = 0;
 
         pmic_plat_data = dev_get_platdata(&i2c->dev);
         if (!pmic_plat_data)
                 return -EINVAL;
 
+        init_data = kzalloc(sizeof(struct tps65910_platform_data), GFP_KERNEL);
+        if (init_data == NULL)
+                return -ENOMEM;
+
+        init_data->irq = pmic_plat_data->irq;
+        init_data->irq_base = pmic_plat_data->irq;
+
         tps65910 = kzalloc(sizeof(struct tps65910), GFP_KERNEL);
         if (tps65910 == NULL)
                 return -ENOMEM;
@@ -161,6 +169,10 @@ static int tps65910_i2c_probe(struct i2c_client *i2c,
 
         tps65910_gpio_init(tps65910, pmic_plat_data->gpio_base);
 
+        ret = tps65910_irq_init(tps65910, init_data->irq, init_data);
+        if (ret < 0)
+                goto err;
+
         return ret;
 
 err: