4 files changed, 335 insertions, 0 deletions

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index 2fc6a66f39a4..0f6c7fb418e8 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -13,3 +13,6 @@ config REGMAP_I2C
 
 config REGMAP_SPI
         tristate
+
+config REGMAP_IRQ
+        bool
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 0573c8a9dacb..ce2d18a6465b 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o regcache-rbtree.o
 obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
 obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o
+obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
new file mode 100644
index 000000000000..bd54f63be9ed
--- /dev/null
+++ b/drivers/base/regmap/regmap-irq.c
@@ -0,0 +1,284 @@
+/*
+ * regmap based irq_chip
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.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/export.h>
+#include <linux/regmap.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+struct regmap_irq_chip_data {
+        struct mutex lock;
+
+        struct regmap *map;
+        struct regmap_irq_chip *chip;
+
+        int irq_base;
+
+        void *status_reg_buf;
+        unsigned int *status_buf;
+        unsigned int *mask_buf;
+        unsigned int *mask_buf_def;
+};
+
+static inline const
+struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
+                                     int irq)
+{
+        return &data->chip->irqs[irq - data->irq_base];
+}
+
+static void regmap_irq_lock(struct irq_data *data)
+{
+        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+
+        mutex_lock(&d->lock);
+}
+
+static void regmap_irq_sync_unlock(struct irq_data *data)
+{
+        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+        int i, ret;
+
+        /*
+         * If there's been a change in the mask write it back to the
+         * hardware.  We rely on the use of the regmap core cache to
+         * suppress pointless writes.
+         */
+        for (i = 0; i < d->chip->num_regs; i++) {
+                ret = regmap_update_bits(d->map, d->chip->mask_base + i,
+                                         d->mask_buf_def[i], d->mask_buf[i]);
+                if (ret != 0)
+                        dev_err(d->map->dev, "Failed to sync masks in %x\n",
+                                d->chip->mask_base + i);
+        }
+
+        mutex_unlock(&d->lock);
+}
+
+static void regmap_irq_enable(struct irq_data *data)
+{
+        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+        const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq);
+
+        d->mask_buf[irq_data->reg_offset] &= ~irq_data->mask;
+}
+
+static void regmap_irq_disable(struct irq_data *data)
+{
+        struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+        const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq);
+
+        d->mask_buf[irq_data->reg_offset] |= irq_data->mask;
+}
+
+static struct irq_chip regmap_irq_chip = {
+        .name                   = "regmap",
+        .irq_bus_lock           = regmap_irq_lock,
+        .irq_bus_sync_unlock    = regmap_irq_sync_unlock,
+        .irq_disable            = regmap_irq_disable,
+        .irq_enable             = regmap_irq_enable,
+};
+
+static irqreturn_t regmap_irq_thread(int irq, void *d)
+{
+        struct regmap_irq_chip_data *data = d;
+        struct regmap_irq_chip *chip = data->chip;
+        struct regmap *map = data->map;
+        int ret, i;
+        u8 *buf8 = data->status_reg_buf;
+        u16 *buf16 = data->status_reg_buf;
+        u32 *buf32 = data->status_reg_buf;
+
+        ret = regmap_bulk_read(map, chip->status_base, data->status_reg_buf,
+                               chip->num_regs);
+        if (ret != 0) {
+                dev_err(map->dev, "Failed to read IRQ status: %d\n", ret);
+                return IRQ_NONE;
+        }
+
+        /*
+         * Ignore masked IRQs and ack if we need to; we ack early so
+         * there is no race between handling and acknowleding the
+         * interrupt.  We assume that typically few of the interrupts
+         * will fire simultaneously so don't worry about overhead from
+         * doing a write per register.
+         */
+        for (i = 0; i < data->chip->num_regs; i++) {
+                switch (map->format.val_bytes) {
+                case 1:
+                        data->status_buf[i] = buf8[i];
+                        break;
+                case 2:
+                        data->status_buf[i] = buf16[i];
+                        break;
+                case 4:
+                        data->status_buf[i] = buf32[i];
+                        break;
+                default:
+                        BUG();
+                        return IRQ_NONE;
+                }
+
+                data->status_buf[i] &= ~data->mask_buf[i];
+
+                if (data->status_buf[i] && chip->ack_base) {
+                        ret = regmap_write(map, chip->ack_base + i,
+                                           data->status_buf[i]);
+                        if (ret != 0)
+                                dev_err(map->dev, "Failed to ack 0x%x: %d\n",
+                                        chip->ack_base + i, ret);
+                }
+        }
+
+        for (i = 0; i < chip->num_irqs; i++) {
+                if (data->status_buf[chip->irqs[i].reg_offset] &
+                    chip->irqs[i].mask) {
+                        handle_nested_irq(data->irq_base + i);
+                }
+        }
+
+        return IRQ_HANDLED;
+}
+
+/**
+ * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
+ *
+ * map:       The regmap for the device.
+ * irq:       The IRQ the device uses to signal interrupts
+ * irq_flags: The IRQF_ flags to use for the primary interrupt.
+ * chip:      Configuration for the interrupt controller.
+ * data:      Runtime data structure for the controller, allocated on success
+ *
+ * Returns 0 on success or an errno on failure.
+ *
+ * In order for this to be efficient the chip really should use a
+ * register cache.  The chip driver is responsible for restoring the
+ * register values used by the IRQ controller over suspend and resume.
+ */
+int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
+                        int irq_base, struct regmap_irq_chip *chip,
+                        struct regmap_irq_chip_data **data)
+{
+        struct regmap_irq_chip_data *d;
+        int cur_irq, i;
+        int ret = -ENOMEM;
+
+        irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
+        if (irq_base < 0) {
+                dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
+                         irq_base);
+                return irq_base;
+        }
+
+        d = kzalloc(sizeof(*d), GFP_KERNEL);
+        if (!d)
+                return -ENOMEM;
+
+        d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
+                                GFP_KERNEL);
+        if (!d->status_buf)
+                goto err_alloc;
+
+        d->status_reg_buf = kzalloc(map->format.val_bytes * chip->num_regs,
+                                    GFP_KERNEL);
+        if (!d->status_reg_buf)
+                goto err_alloc;
+
+        d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
+                              GFP_KERNEL);
+        if (!d->mask_buf)
+                goto err_alloc;
+
+        d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
+                                  GFP_KERNEL);
+        if (!d->mask_buf_def)
+                goto err_alloc;
+
+        d->map = map;
+        d->chip = chip;
+        d->irq_base = irq_base;
+        mutex_init(&d->lock);
+
+        for (i = 0; i < chip->num_irqs; i++)
+                d->mask_buf_def[chip->irqs[i].reg_offset]
+                        |= chip->irqs[i].mask;
+
+        /* Mask all the interrupts by default */
+        for (i = 0; i < chip->num_regs; i++) {
+                d->mask_buf[i] = d->mask_buf_def[i];
+                ret = regmap_write(map, chip->mask_base + i, d->mask_buf[i]);
+                if (ret != 0) {
+                        dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
+                                chip->mask_base + i, ret);
+                        goto err_alloc;
+                }
+        }
+
+        /* Register them with genirq */
+        for (cur_irq = irq_base;
+             cur_irq < chip->num_irqs + irq_base;
+             cur_irq++) {
+                irq_set_chip_data(cur_irq, d);
+                irq_set_chip_and_handler(cur_irq, &regmap_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, regmap_irq_thread, irq_flags,
+                                   chip->name, d);
+        if (ret != 0) {
+                dev_err(map->dev, "Failed to request IRQ %d: %d\n", irq, ret);
+                goto err_alloc;
+        }
+
+        return 0;
+
+err_alloc:
+        kfree(d->mask_buf_def);
+        kfree(d->mask_buf);
+        kfree(d->status_reg_buf);
+        kfree(d->status_buf);
+        kfree(d);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_add_irq_chip);
+
+/**
+ * regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
+ *
+ * @irq: Primary IRQ for the device
+ * @d:   regmap_irq_chip_data allocated by regmap_add_irq_chip()
+ */
+void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
+{
+        if (!d)
+                return;
+
+        free_irq(irq, d);
+        kfree(d->mask_buf_def);
+        kfree(d->mask_buf);
+        kfree(d->status_reg_buf);
+        kfree(d->status_buf);
+        kfree(d);
+}
+EXPORT_SYMBOL_GPL(regmap_del_irq_chip);
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 690276a642cf..bd54cecdfdf8 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -144,4 +144,51 @@ int regcache_sync(struct regmap *map);
 void regcache_cache_only(struct regmap *map, bool enable);
 void regcache_cache_bypass(struct regmap *map, bool enable);
 
+/**
+ * Description of an IRQ for the generic regmap irq_chip.
+ *
+ * @reg_offset: Offset of the status/mask register within the bank
+ * @mask:       Mask used to flag/control the register.
+ */
+struct regmap_irq {
+        unsigned int reg_offset;
+        unsigned int mask;
+};
+
+/**
+ * Description of a generic regmap irq_chip.  This is not intended to
+ * handle every possible interrupt controller, but it should handle a
+ * substantial proportion of those that are found in the wild.
+ *
+ * @name:        Descriptive name for IRQ controller.
+ *
+ * @status_base: Base status register address.
+ * @mask_base:   Base mask register address.
+ * @ack_base:    Base ack address.  If zero then the chip is clear on read.
+ *
+ * @num_regs:    Number of registers in each control bank.
+ * @irqs:        Descriptors for individual IRQs.  Interrupt numbers are
+ *               assigned based on the index in the array of the interrupt.
+ * @num_irqs:    Number of descriptors.
+ */
+struct regmap_irq_chip {
+        const char *name;
+
+        unsigned int status_base;
+        unsigned int mask_base;
+        unsigned int ack_base;
+
+        int num_regs;
+
+        const struct regmap_irq *irqs;
+        int num_irqs;
+};
+
+struct regmap_irq_chip_data;
+
+int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
+                        int irq_base, struct regmap_irq_chip *chip,
+                        struct regmap_irq_chip_data **data);
+void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *data);
+
 #endif