1 files changed, 198 insertions, 0 deletions

diff --git a/drivers/mfd/lp8788-irq.c b/drivers/mfd/lp8788-irq.c
new file mode 100644
index 000000000000..c84ded5f8ece
--- /dev/null
+++ b/drivers/mfd/lp8788-irq.c
@@ -0,0 +1,198 @@
+/*
+ * TI LP8788 MFD - interrupt handler
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@ti.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/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/device.h>
+#include <linux/mfd/lp8788.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/* register address */
+#define LP8788_INT_1                    0x00
+#define LP8788_INTEN_1                  0x03
+
+#define BASE_INTEN_ADDR                 LP8788_INTEN_1
+#define SIZE_REG                        8
+#define NUM_REGS                        3
+
+/*
+ * struct lp8788_irq_data
+ * @lp               : used for accessing to lp8788 registers
+ * @irq_lock         : mutex for enabling/disabling the interrupt
+ * @domain           : IRQ domain for handling nested interrupt
+ * @enabled          : status of enabled interrupt
+ */
+struct lp8788_irq_data {
+        struct lp8788 *lp;
+        struct mutex irq_lock;
+        struct irq_domain *domain;
+        int enabled[LP8788_INT_MAX];
+};
+
+static inline u8 _irq_to_addr(enum lp8788_int_id id)
+{
+        return id / SIZE_REG;
+}
+
+static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
+{
+        return _irq_to_addr(id) + BASE_INTEN_ADDR;
+}
+
+static inline u8 _irq_to_mask(enum lp8788_int_id id)
+{
+        return 1 << (id % SIZE_REG);
+}
+
+static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
+{
+        return enable << (id % SIZE_REG);
+}
+
+static void lp8788_irq_enable(struct irq_data *data)
+{
+        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+        irqd->enabled[data->hwirq] = 1;
+}
+
+static void lp8788_irq_disable(struct irq_data *data)
+{
+        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+        irqd->enabled[data->hwirq] = 0;
+}
+
+static void lp8788_irq_bus_lock(struct irq_data *data)
+{
+        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+
+        mutex_lock(&irqd->irq_lock);
+}
+
+static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
+{
+        struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+        enum lp8788_int_id irq = data->hwirq;
+        u8 addr, mask, val;
+
+        addr = _irq_to_enable_addr(irq);
+        mask = _irq_to_mask(irq);
+        val = _irq_to_val(irq, irqd->enabled[irq]);
+
+        lp8788_update_bits(irqd->lp, addr, mask, val);
+
+        mutex_unlock(&irqd->irq_lock);
+}
+
+static struct irq_chip lp8788_irq_chip = {
+        .name                   = "lp8788",
+        .irq_enable             = lp8788_irq_enable,
+        .irq_disable            = lp8788_irq_disable,
+        .irq_bus_lock           = lp8788_irq_bus_lock,
+        .irq_bus_sync_unlock    = lp8788_irq_bus_sync_unlock,
+};
+
+static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
+{
+        struct lp8788_irq_data *irqd = ptr;
+        struct lp8788 *lp = irqd->lp;
+        u8 status[NUM_REGS], addr, mask;
+        bool handled;
+        int i;
+
+        if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
+                return IRQ_NONE;
+
+        for (i = 0 ; i < LP8788_INT_MAX ; i++) {
+                addr = _irq_to_addr(i);
+                mask = _irq_to_mask(i);
+
+                /* reporting only if the irq is enabled */
+                if (status[addr] & mask) {
+                        handle_nested_irq(irq_find_mapping(irqd->domain, i));
+                        handled = true;
+                }
+        }
+
+        return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
+                        irq_hw_number_t hwirq)
+{
+        struct lp8788_irq_data *irqd = d->host_data;
+        struct irq_chip *chip = &lp8788_irq_chip;
+
+        irq_set_chip_data(virq, irqd);
+        irq_set_chip_and_handler(virq, chip, handle_edge_irq);
+        irq_set_nested_thread(virq, 1);
+
+#ifdef CONFIG_ARM
+        set_irq_flags(virq, IRQF_VALID);
+#else
+        irq_set_noprobe(virq);
+#endif
+
+        return 0;
+}
+
+static struct irq_domain_ops lp8788_domain_ops = {
+        .map = lp8788_irq_map,
+};
+
+int lp8788_irq_init(struct lp8788 *lp, int irq)
+{
+        struct lp8788_irq_data *irqd;
+        int ret;
+
+        if (irq <= 0) {
+                dev_warn(lp->dev, "invalid irq number: %d\n", irq);
+                return 0;
+        }
+
+        irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
+        if (!irqd)
+                return -ENOMEM;
+
+        irqd->lp = lp;
+        irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
+                                        &lp8788_domain_ops, irqd);
+        if (!irqd->domain) {
+                dev_err(lp->dev, "failed to add irq domain err\n");
+                return -EINVAL;
+        }
+
+        lp->irqdm = irqd->domain;
+        mutex_init(&irqd->irq_lock);
+
+        ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
+                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+                                "lp8788-irq", irqd);
+        if (ret) {
+                dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
+                return ret;
+        }
+
+        lp->irq = irq;
+
+        return 0;
+}
+
+void lp8788_irq_exit(struct lp8788 *lp)
+{
+        if (lp->irq)
+                free_irq(lp->irq, lp->irqdm);
+}