mfd: max8998: Add irq domain support

This patch adds irq domain support for max8998 interrupts.

To keep both non-DT and DT worlds happy, simple domain is used, which is
linear when no explicit IRQ base is specified and legacy, with static
mapping, otherwise.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 52 insertions, 26 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3bb2932eafb1..aecd6ddcbbbf 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -363,6 +363,7 @@ config MFD_MAX8998
         bool "Maxim Semiconductor MAX8998/National LP3974 PMIC Support"
         depends on I2C=y && GENERIC_HARDIRQS
         select MFD_CORE
+        select IRQ_DOMAIN
         help
           Say yes here to support for Maxim Semiconductor MAX8998 and
           National Semiconductor LP3974. This is a Power Management IC.
diff --git a/drivers/mfd/max8998-irq.c b/drivers/mfd/max8998-irq.c
index 5919710dc9ed..c469477eb778 100644
--- a/drivers/mfd/max8998-irq.c
+++ b/drivers/mfd/max8998-irq.c
@@ -14,6 +14,7 @@
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/mfd/max8998-private.h>
 
 struct max8998_irq_data {
@@ -99,7 +100,8 @@ static struct max8998_irq_data max8998_irqs[] = {
 static inline struct max8998_irq_data *
 irq_to_max8998_irq(struct max8998_dev *max8998, int irq)
 {
-        return &max8998_irqs[irq - max8998->irq_base];
+        struct irq_data *data = irq_get_irq_data(irq);
+        return &max8998_irqs[data->hwirq];
 }
 
 static void max8998_irq_lock(struct irq_data *data)
@@ -176,8 +178,14 @@ static irqreturn_t max8998_irq_thread(int irq, void *data)
 
         /* Report */
         for (i = 0; i < MAX8998_IRQ_NR; i++) {
-                if (irq_reg[max8998_irqs[i].reg - 1] & max8998_irqs[i].mask)
-                        handle_nested_irq(max8998->irq_base + i);
+                if (irq_reg[max8998_irqs[i].reg - 1] & max8998_irqs[i].mask) {
+                        irq = irq_find_mapping(max8998->irq_domain, i);
+                        if (WARN_ON(!irq)) {
+                                disable_irq_nosync(max8998->irq);
+                                return IRQ_NONE;
+                        }
+                        handle_nested_irq(irq);
+                }
         }
 
         return IRQ_HANDLED;
@@ -185,27 +193,40 @@ static irqreturn_t max8998_irq_thread(int irq, void *data)
 
 int max8998_irq_resume(struct max8998_dev *max8998)
 {
-        if (max8998->irq && max8998->irq_base)
-                max8998_irq_thread(max8998->irq_base, max8998);
+        if (max8998->irq && max8998->irq_domain)
+                max8998_irq_thread(max8998->irq, max8998);
+        return 0;
+}
+
+static int max8998_irq_domain_map(struct irq_domain *d, unsigned int irq,
+                                        irq_hw_number_t hw)
+{
+        struct max8997_dev *max8998 = d->host_data;
+
+        irq_set_chip_data(irq, max8998);
+        irq_set_chip_and_handler(irq, &max8998_irq_chip, handle_edge_irq);
+        irq_set_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+        set_irq_flags(irq, IRQF_VALID);
+#else
+        irq_set_noprobe(irq);
+#endif
         return 0;
 }
 
+static struct irq_domain_ops max8998_irq_domain_ops = {
+        .map = max8998_irq_domain_map,
+};
+
 int max8998_irq_init(struct max8998_dev *max8998)
 {
         int i;
-        int cur_irq;
         int ret;
+        struct irq_domain *domain;
 
         if (!max8998->irq) {
                 dev_warn(max8998->dev,
                          "No interrupt specified, no interrupts\n");
-                max8998->irq_base = 0;
-                return 0;
-        }
-
-        if (!max8998->irq_base) {
-                dev_err(max8998->dev,
-                        "No interrupt base specified, no interrupts\n");
                 return 0;
         }
 
@@ -221,19 +242,13 @@ int max8998_irq_init(struct max8998_dev *max8998)
         max8998_write_reg(max8998->i2c, MAX8998_REG_STATUSM1, 0xff);
         max8998_write_reg(max8998->i2c, MAX8998_REG_STATUSM2, 0xff);
 
-        /* register with genirq */
-        for (i = 0; i < MAX8998_IRQ_NR; i++) {
-                cur_irq = i + max8998->irq_base;
-                irq_set_chip_data(cur_irq, max8998);
-                irq_set_chip_and_handler(cur_irq, &max8998_irq_chip,
-                                         handle_edge_irq);
-                irq_set_nested_thread(cur_irq, 1);
-#ifdef CONFIG_ARM
-                set_irq_flags(cur_irq, IRQF_VALID);
-#else
-                irq_set_noprobe(cur_irq);
-#endif
+        domain = irq_domain_add_simple(NULL, MAX8998_IRQ_NR,
+                        max8998->irq_base, &max8998_irq_domain_ops, max8998);
+        if (!domain) {
+                dev_err(max8998->dev, "could not create irq domain\n");
+                return -ENODEV;
         }
+        max8998->irq_domain = domain;
 
         ret = request_threaded_irq(max8998->irq, NULL, max8998_irq_thread,
                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c
index d5af7baa48b5..46f23014759b 100644
--- a/drivers/rtc/rtc-max8998.c
+++ b/drivers/rtc/rtc-max8998.c
@@ -16,6 +16,7 @@
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/bcd.h>
+#include <linux/irqdomain.h>
 #include <linux/rtc.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/max8998.h>
@@ -264,7 +265,6 @@ static int max8998_rtc_probe(struct platform_device *pdev)
         info->dev = &pdev->dev;
         info->max8998 = max8998;
         info->rtc = max8998->rtc;
-        info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;
 
         platform_set_drvdata(pdev, info);
 
@@ -277,6 +277,15 @@ static int max8998_rtc_probe(struct platform_device *pdev)
                 goto out_rtc;
         }
 
+        if (!max8998->irq_domain)
+                goto no_irq;
+
+        info->irq = irq_create_mapping(max8998->irq_domain, MAX8998_IRQ_ALARM0);
+        if (!info->irq) {
+                dev_warn(&pdev->dev, "Failed to map alarm IRQ\n");
+                goto no_irq;
+        }
+
         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
                                 max8998_rtc_alarm_irq, 0, "rtc-alarm0", info);
 
@@ -284,6 +293,7 @@ static int max8998_rtc_probe(struct platform_device *pdev)
                 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
                         info->irq, ret);
 
+no_irq:
         dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name);
         if (pdata && pdata->rtc_delay) {
                 info->lp3974_bug_workaround = true;