ARM: at91/gpio: add irqdomain and DT support

Add "legacy" type of irqdomain to preserve old-style numbering
and allow smooth transition for both DT and non-DT cases.

Original idea and code by Jean-Christophe Plagniol-Villard.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

5 files changed, 291 insertions, 46 deletions

diff --git a/Documentation/devicetree/bindings/gpio/gpio_atmel.txt b/Documentation/devicetree/bindings/gpio/gpio_atmel.txt
new file mode 100644
index 000000000000..a7bcaec913bf
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio_atmel.txt
@@ -0,0 +1,20 @@
+* Atmel GPIO controller (PIO)
+
+Required properties:
+- compatible: "atmel,at91rm9200-gpio"
+- reg: Should contain GPIO controller registers location and length
+- interrupts: Should be the port interrupt shared by all the pins.
+- #gpio-cells: Should be two.  The first cell is the pin number and
+  the second cell is used to specify optional parameters (currently
+  unused).
+- gpio-controller: Marks the device node as a GPIO controller.
+
+Example:
+        pioA: gpio@fffff200 {
+                compatible = "atmel,at91rm9200-gpio";
+                reg = <0xfffff200 0x100>;
+                interrupts = <2 4>;
+                #gpio-cells = <2>;
+                gpio-controller;
+        };
+
diff --git a/arch/arm/boot/dts/at91sam9g20.dtsi b/arch/arm/boot/dts/at91sam9g20.dtsi
index 9a0aee791a40..325989a27a7a 100644
--- a/arch/arm/boot/dts/at91sam9g20.dtsi
+++ b/arch/arm/boot/dts/at91sam9g20.dtsi
@@ -23,6 +23,9 @@
                 serial4 = &usart3;
                 serial5 = &usart4;
                 serial6 = &usart5;
+                gpio0 = &pioA;
+                gpio1 = &pioB;
+                gpio2 = &pioC;
         };
         cpus {
                 cpu@0 {
@@ -54,6 +57,33 @@
                                 reg = <0xfffff000 0x200>;
                         };
 
+                        pioA: gpio@fffff400 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff400 0x100>;
+                                interrupts = <2 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
+                        pioB: gpio@fffff600 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff600 0x100>;
+                                interrupts = <3 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
+                        pioC: gpio@fffff800 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff800 0x100>;
+                                interrupts = <4 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
                         dbgu: serial@fffff200 {
                                 compatible = "atmel,at91sam9260-usart";
                                 reg = <0xfffff200 0x200>;
diff --git a/arch/arm/boot/dts/at91sam9g45.dtsi b/arch/arm/boot/dts/at91sam9g45.dtsi
index 67f94d3698a2..a9dbbb5b86f5 100644
--- a/arch/arm/boot/dts/at91sam9g45.dtsi
+++ b/arch/arm/boot/dts/at91sam9g45.dtsi
@@ -22,6 +22,11 @@
                 serial2 = &usart1;
                 serial3 = &usart2;
                 serial4 = &usart3;
+                gpio0 = &pioA;
+                gpio1 = &pioB;
+                gpio2 = &pioC;
+                gpio3 = &pioD;
+                gpio4 = &pioE;
         };
         cpus {
                 cpu@0 {
@@ -59,6 +64,51 @@
                                 interrupts = <21 4>;
                         };
 
+                        pioA: gpio@fffff200 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff200 0x100>;
+                                interrupts = <2 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
+                        pioB: gpio@fffff400 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff400 0x100>;
+                                interrupts = <3 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
+                        pioC: gpio@fffff600 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff600 0x100>;
+                                interrupts = <4 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
+                        pioD: gpio@fffff800 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffff800 0x100>;
+                                interrupts = <5 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
+                        pioE: gpio@fffffa00 {
+                                compatible = "atmel,at91rm9200-gpio";
+                                reg = <0xfffffa00 0x100>;
+                                interrupts = <5 4>;
+                                #gpio-cells = <2>;
+                                gpio-controller;
+                                interrupt-controller;
+                        };
+
                         dbgu: serial@ffffee00 {
                                 compatible = "atmel,at91sam9260-usart";
                                 reg = <0xffffee00 0x200>;
diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi
index e91391f50730..bb0c676b3393 100644
--- a/arch/arm/boot/dts/at91sam9x5.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5.dtsi
@@ -94,6 +94,7 @@
                                 interrupts = <2 4>;
                                 #gpio-cells = <2>;
                                 gpio-controller;
+                                interrupt-controller;
                         };
 
                         pioB: gpio@fffff600 {
@@ -102,6 +103,7 @@
                                 interrupts = <2 4>;
                                 #gpio-cells = <2>;
                                 gpio-controller;
+                                interrupt-controller;
                         };
 
                         pioC: gpio@fffff800 {
@@ -110,6 +112,7 @@
                                 interrupts = <3 4>;
                                 #gpio-cells = <2>;
                                 gpio-controller;
+                                interrupt-controller;
                         };
 
                         pioD: gpio@fffffa00 {
@@ -118,6 +121,7 @@
                                 interrupts = <3 4>;
                                 #gpio-cells = <2>;
                                 gpio-controller;
+                                interrupt-controller;
                         };
 
                         dbgu: serial@fffff200 {
diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
index b762afc4ec17..89e683aaae6c 100644
--- a/arch/arm/mach-at91/gpio.c
+++ b/arch/arm/mach-at91/gpio.c
@@ -20,6 +20,9 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
 
 #include <mach/hardware.h>
 #include <mach/at91_pio.h>
@@ -30,8 +33,10 @@ struct at91_gpio_chip {
         struct gpio_chip        chip;
         struct at91_gpio_chip   *next;          /* Bank sharing same clock */
         int                     pioc_hwirq;     /* PIO bank interrupt identifier on AIC */
+        int                     pioc_idx;       /* PIO bank index */
         void __iomem            *regbase;       /* PIO bank virtual address */
         struct clk              *clock;         /* associated clock */
+        struct irq_domain       *domain;        /* associated irq domain */
 };
 
 #define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip)
@@ -273,9 +278,9 @@ static u32 backups[MAX_GPIO_BANKS];
 
 static int gpio_irq_set_wake(struct irq_data *d, unsigned state)
 {
-        unsigned        pin = irq_to_gpio(d->irq);
-        unsigned        mask = pin_to_mask(pin);
-        unsigned        bank = pin / 32;
+        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
+        unsigned        mask = 1 << d->hwirq;
+        unsigned        bank = at91_gpio->pioc_idx;
 
         if (unlikely(bank >= MAX_GPIO_BANKS))
                 return -EINVAL;
@@ -301,9 +306,10 @@ void at91_gpio_suspend(void)
                 __raw_writel(backups[i], pio + PIO_IDR);
                 __raw_writel(wakeups[i], pio + PIO_IER);
 
-                if (!wakeups[i])
+                if (!wakeups[i]) {
+                        clk_unprepare(gpio_chip[i].clock);
                         clk_disable(gpio_chip[i].clock);
-                else {
+                } else {
 #ifdef CONFIG_PM_DEBUG
                         printk(KERN_DEBUG "GPIO-%c may wake for %08x\n", 'A'+i, wakeups[i]);
 #endif
@@ -318,8 +324,10 @@ void at91_gpio_resume(void)
         for (i = 0; i < gpio_banks; i++) {
                 void __iomem    *pio = gpio_chip[i].regbase;
 
-                if (!wakeups[i])
-                        clk_enable(gpio_chip[i].clock);
+                if (!wakeups[i]) {
+                        if (clk_prepare(gpio_chip[i].clock) == 0)
+                                clk_enable(gpio_chip[i].clock);
+                }
 
                 __raw_writel(wakeups[i], pio + PIO_IDR);
                 __raw_writel(backups[i], pio + PIO_IER);
@@ -344,9 +352,9 @@ void at91_gpio_resume(void)
 
 static void gpio_irq_mask(struct irq_data *d)
 {
-        unsigned        pin = irq_to_gpio(d->irq);
-        void __iomem    *pio = pin_to_controller(pin);
-        unsigned        mask = pin_to_mask(pin);
+        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
+        void __iomem    *pio = at91_gpio->regbase;
+        unsigned        mask = 1 << d->hwirq;
 
         if (pio)
                 __raw_writel(mask, pio + PIO_IDR);
@@ -354,9 +362,9 @@ static void gpio_irq_mask(struct irq_data *d)
 
 static void gpio_irq_unmask(struct irq_data *d)
 {
-        unsigned        pin = irq_to_gpio(d->irq);
-        void __iomem    *pio = pin_to_controller(pin);
-        unsigned        mask = pin_to_mask(pin);
+        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
+        void __iomem    *pio = at91_gpio->regbase;
+        unsigned        mask = 1 << d->hwirq;
 
         if (pio)
                 __raw_writel(mask, pio + PIO_IER);
@@ -384,7 +392,7 @@ static struct irq_chip gpio_irqchip = {
 
 static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
 {
-        unsigned        irq_pin;
+        unsigned        virq;
         struct irq_data *idata = irq_desc_get_irq_data(desc);
         struct irq_chip *chip = irq_data_get_irq_chip(idata);
         struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(idata);
@@ -407,12 +415,12 @@ static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
                         continue;
                 }
 
-                irq_pin = gpio_to_irq(at91_gpio->chip.base);
+                virq = gpio_to_irq(at91_gpio->chip.base);
 
                 while (isr) {
                         if (isr & 1)
-                                generic_handle_irq(irq_pin);
-                        irq_pin++;
+                                generic_handle_irq(virq);
+                        virq++;
                         isr >>= 1;
                 }
         }
@@ -483,6 +491,26 @@ postcore_initcall(at91_gpio_debugfs_init);
 /*--------------------------------------------------------------------------*/
 
 /*
+ * irqdomain initialization: pile up irqdomains on top of AIC range
+ */
+static void __init at91_gpio_irqdomain(struct at91_gpio_chip *at91_gpio)
+{
+        int irq_base;
+
+        irq_base = irq_alloc_descs(-1, 0, at91_gpio->chip.ngpio, 0);
+        if (irq_base < 0)
+                panic("at91_gpio.%d: error %d: couldn't allocate IRQ numbers.\n",
+                        at91_gpio->pioc_idx, irq_base);
+        at91_gpio->domain = irq_domain_add_legacy(at91_gpio->chip.of_node,
+                                                  at91_gpio->chip.ngpio,
+                                                  irq_base, 0,
+                                                  &irq_domain_simple_ops, NULL);
+        if (!at91_gpio->domain)
+                panic("at91_gpio.%d: couldn't allocate irq domain.\n",
+                        at91_gpio->pioc_idx);
+}
+
+/*
  * This lock class tells lockdep that GPIO irqs are in a different
  * category than their parents, so it won't report false recursion.
  */
@@ -493,28 +521,35 @@ static struct lock_class_key gpio_lock_class;
  */
 void __init at91_gpio_irq_setup(void)
 {
-        unsigned                pioc, irq = gpio_to_irq(0);
+        unsigned                pioc;
+        int                     gpio_irqnbr = 0;
         struct at91_gpio_chip   *this, *prev;
 
         for (pioc = 0, this = gpio_chip, prev = NULL;
                         pioc++ < gpio_banks;
                         prev = this, this++) {
                 unsigned        pioc_hwirq = this->pioc_hwirq;
-                unsigned        i;
+                int             offset;
 
                 __raw_writel(~0, this->regbase + PIO_IDR);
 
-                for (i = 0, irq = gpio_to_irq(this->chip.base); i < 32;
-                     i++, irq++) {
-                        irq_set_lockdep_class(irq, &gpio_lock_class);
+                /* setup irq domain for this GPIO controller */
+                at91_gpio_irqdomain(this);
+
+                for (offset = 0; offset < this->chip.ngpio; offset++) {
+                        unsigned int virq = irq_find_mapping(this->domain, offset);
+                        irq_set_lockdep_class(virq, &gpio_lock_class);
 
                         /*
                          * Can use the "simple" and not "edge" handler since it's
                          * shorter, and the AIC handles interrupts sanely.
                          */
-                        irq_set_chip_and_handler(irq, &gpio_irqchip,
+                        irq_set_chip_and_handler(virq, &gpio_irqchip,
                                                  handle_simple_irq);
-                        set_irq_flags(irq, IRQF_VALID);
+                        set_irq_flags(virq, IRQF_VALID);
+                        irq_set_chip_data(virq, this);
+
+                        gpio_irqnbr++;
                 }
 
                 /* The toplevel handler handles one bank of GPIOs, except
@@ -527,7 +562,7 @@ void __init at91_gpio_irq_setup(void)
                 irq_set_chip_data(pioc_hwirq, this);
                 irq_set_chained_handler(pioc_hwirq, gpio_irq_handler);
         }
-        pr_info("AT91: %d gpio irqs in %d banks\n", irq - gpio_to_irq(0), gpio_banks);
+        pr_info("AT91: %d gpio irqs in %d banks\n", gpio_irqnbr, gpio_banks);
 }
 
 /* gpiolib support */
@@ -600,39 +635,145 @@ static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
         }
 }
 
+static int __init at91_gpio_setup_clk(int idx)
+{
+        struct at91_gpio_chip *at91_gpio = &gpio_chip[idx];
+
+        /* retreive PIO controller's clock */
+        at91_gpio->clock = clk_get_sys(NULL, at91_gpio->chip.label);
+        if (IS_ERR(at91_gpio->clock)) {
+                pr_err("at91_gpio.%d, failed to get clock, ignoring.\n", idx);
+                goto err;
+        }
+
+        if (clk_prepare(at91_gpio->clock))
+                goto clk_prep_err;
+
+        /* enable PIO controller's clock */
+        if (clk_enable(at91_gpio->clock)) {
+                pr_err("at91_gpio.%d, failed to enable clock, ignoring.\n", idx);
+                goto clk_err;
+        }
+
+        return 0;
+
+clk_err:
+        clk_unprepare(at91_gpio->clock);
+clk_prep_err:
+        clk_put(at91_gpio->clock);
+err:
+        return -EINVAL;
+}
+
+#ifdef CONFIG_OF_GPIO
+static void __init of_at91_gpio_init_one(struct device_node *np)
+{
+        int alias_idx;
+        struct at91_gpio_chip *at91_gpio;
+
+        if (!np)
+                return;
+
+        alias_idx = of_alias_get_id(np, "gpio");
+        if (alias_idx >= MAX_GPIO_BANKS) {
+                pr_err("at91_gpio, failed alias idx(%d) > MAX_GPIO_BANKS(%d), ignoring.\n",
+                                                alias_idx, MAX_GPIO_BANKS);
+                return;
+        }
+
+        at91_gpio = &gpio_chip[alias_idx];
+        at91_gpio->chip.base = alias_idx * at91_gpio->chip.ngpio;
+
+        at91_gpio->regbase = of_iomap(np, 0);
+        if (!at91_gpio->regbase) {
+                pr_err("at91_gpio.%d, failed to map registers, ignoring.\n",
+                                                                alias_idx);
+                return;
+        }
+
+        /* Get the interrupts property */
+        if (of_property_read_u32(np, "interrupts", &at91_gpio->pioc_hwirq)) {
+                pr_err("at91_gpio.%d, failed to get interrupts property, ignoring.\n",
+                                                                alias_idx);
+                goto ioremap_err;
+        }
+
+        /* Setup clock */
+        if (at91_gpio_setup_clk(alias_idx))
+                goto ioremap_err;
+
+        at91_gpio->chip.of_node = np;
+        gpio_banks = max(gpio_banks, alias_idx + 1);
+        at91_gpio->pioc_idx = alias_idx;
+        return;
+
+ioremap_err:
+        iounmap(at91_gpio->regbase);
+}
+
+static int __init of_at91_gpio_init(void)
+{
+        struct device_node *np = NULL;
+
+        /*
+         * This isn't ideal, but it gets things hooked up until this
+         * driver is converted into a platform_device
+         */
+        for_each_compatible_node(np, NULL, "atmel,at91rm9200-gpio")
+                of_at91_gpio_init_one(np);
+
+        return gpio_banks > 0 ? 0 : -EINVAL;
+}
+#else
+static int __init of_at91_gpio_init(void)
+{
+        return -EINVAL;
+}
+#endif
+
+static void __init at91_gpio_init_one(int idx, u32 regbase, int pioc_hwirq)
+{
+        struct at91_gpio_chip *at91_gpio = &gpio_chip[idx];
+
+        at91_gpio->chip.base = idx * at91_gpio->chip.ngpio;
+        at91_gpio->pioc_hwirq = pioc_hwirq;
+        at91_gpio->pioc_idx = idx;
+
+        at91_gpio->regbase = ioremap(regbase, 512);
+        if (!at91_gpio->regbase) {
+                pr_err("at91_gpio.%d, failed to map registers, ignoring.\n", idx);
+                return;
+        }
+
+        if (at91_gpio_setup_clk(idx))
+                goto ioremap_err;
+
+        gpio_banks = max(gpio_banks, idx + 1);
+        return;
+
+ioremap_err:
+        iounmap(at91_gpio->regbase);
+}
+
 /*
  * Called from the processor-specific init to enable GPIO pin support.
  */
 void __init at91_gpio_init(struct at91_gpio_bank *data, int nr_banks)
 {
-        unsigned                i;
+        unsigned i;
         struct at91_gpio_chip *at91_gpio, *last = NULL;
 
         BUG_ON(nr_banks > MAX_GPIO_BANKS);
 
-        gpio_banks = nr_banks;
+        if (of_at91_gpio_init() < 0) {
+                /* No GPIO controller found in device tree */
+                for (i = 0; i < nr_banks; i++)
+                        at91_gpio_init_one(i, data[i].regbase, data[i].id);
+        }
 
-        for (i = 0; i < nr_banks; i++) {
+        for (i = 0; i < gpio_banks; i++) {
                 at91_gpio = &gpio_chip[i];
 
-                at91_gpio->pioc_hwirq = data[i].pioc_hwirq;
-                at91_gpio->chip.base = i * 32;
-
-                at91_gpio->regbase = ioremap(data[i].regbase, 512);
-                if (!at91_gpio->regbase) {
-                        pr_err("at91_gpio.%d, failed to map registers, ignoring.\n", i);
-                        continue;
-                }
-
-                at91_gpio->clock = clk_get_sys(NULL, at91_gpio->chip.label);
-                if (!at91_gpio->clock) {
-                        pr_err("at91_gpio.%d, failed to get clock, ignoring.\n", i);
-                        continue;
-                }
-
-                /* enable PIO controller's clock */
-                clk_enable(at91_gpio->clock);
-
                 /*
                  * GPIO controller are grouped on some SoC:
                  * PIOC, PIOD and PIOE can share the same IRQ line