[PATCH v4 3/6] ARM: at91/gpio: add DT support
Nicolas Ferre
nicolas.ferre at atmel.com
Fri Jan 6 07:03:16 EST 2012
From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Acked-by: Grant Likely <grant.likely at secretlab.ca>
---
v4: - at91_gpio_setup_clk() returns an error code
v3: - Corrections proposed by Russell King:
- use of clk_prepare()/clk_unprepare()
- helper function to setup the clock for both DT/non DT init functions
v2: - no BUG_ON() anymore in case of an "interrupts" property missing
just stop configuring the gpio bank
- review error path in both of_at91_gpio_init_one() and
at91_gpio_init_one()
- use for_each_compatible_node() iterator instead of a homemade loop
---
.../devicetree/bindings/gpio/gpio_at91.txt | 20 +++
arch/arm/boot/dts/at91sam9g20.dtsi | 28 ++++
arch/arm/boot/dts/at91sam9g45.dtsi | 45 ++++++
arch/arm/mach-at91/gpio.c | 163 ++++++++++++++++---
4 files changed, 230 insertions(+), 26 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio_at91.txt
diff --git a/Documentation/devicetree/bindings/gpio/gpio_at91.txt b/Documentation/devicetree/bindings/gpio/gpio_at91.txt
new file mode 100644
index 0000000..a7bcaec
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio_at91.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 at 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 0782f80..ea942b5 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 at 0 {
@@ -54,6 +57,31 @@
reg = <0xfffff000 0x200>;
};
+
+ pioA: gpio at fffff400 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff400 0x100>;
+ interrupts = <2 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
+ pioB: gpio at fffff600 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff600 0x100>;
+ interrupts = <3 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
+ pioC: gpio at fffff800 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff800 0x100>;
+ interrupts = <4 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
dbgu: serial at 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 e89b1d7..ebc9617 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 at 0 {
@@ -59,6 +64,46 @@
interrupts = <21 4>;
};
+ pioA: gpio at fffff200 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff200 0x100>;
+ interrupts = <2 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
+ pioB: gpio at fffff400 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff400 0x100>;
+ interrupts = <3 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
+ pioC: gpio at fffff600 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff600 0x100>;
+ interrupts = <4 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
+ pioD: gpio at fffff800 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffff800 0x100>;
+ interrupts = <5 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
+ pioE: gpio at fffffa00 {
+ compatible = "atmel,at91rm9200-gpio";
+ reg = <0xfffffa00 0x100>;
+ interrupts = <5 4>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ };
+
dbgu: serial at ffffee00 {
compatible = "atmel,at91sam9260-usart";
reg = <0xffffee00 0x200>;
diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
index 7ffb893..3561912 100644
--- a/arch/arm/mach-at91/gpio.c
+++ b/arch/arm/mach-at91/gpio.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
+#include <linux/of_address.h>
#include <mach/hardware.h>
#include <mach/at91_pio.h>
@@ -303,9 +304,10 @@ 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
@@ -320,8 +322,10 @@ 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);
@@ -624,40 +628,147 @@ static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
}
}
+static int __init at91_gpio_setup_clk(int i)
+{
+ struct at91_gpio_chip *at91_gpio = &gpio_chip[i];
+
+ /* 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", i);
+ 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", i);
+ 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_id;
+ struct at91_gpio_chip *at91_gpio;
+
+ if (!np)
+ return;
+
+ alias_id = of_alias_get_id(np, "gpio");
+ if (alias_id >= MAX_GPIO_BANKS) {
+ pr_err("at91_gpio, failed alias id(%d) > MAX_GPIO_BANKS(%d), ignoring.\n",
+ alias_id, MAX_GPIO_BANKS);
+ return;
+ }
+
+ at91_gpio = &gpio_chip[alias_id];
+ at91_gpio->chip.base = alias_id * 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_id);
+ return;
+ }
+
+ /* Get the interrupts property */
+ if (of_property_read_u32(np, "interrupts", &at91_gpio->id)) {
+ pr_err("at91_gpio.%d, failed to get interrupts property, ignoring.\n",
+ alias_id);
+ goto ioremap_err;
+ }
+
+ /* Setup clock */
+ if (at91_gpio_setup_clk(alias_id))
+ goto ioremap_err;
+
+ at91_gpio->chip.of_node = np;
+ gpio_banks = max(gpio_banks, alias_id + 1);
+ 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 i, u32 regbase, int id)
+{
+ struct at91_gpio_chip *at91_gpio = &gpio_chip[i];
+
+ at91_gpio->chip.base = i * at91_gpio->chip.ngpio;
+ at91_gpio->id = id;
+
+ at91_gpio->regbase = ioremap(regbase, 512);
+ if (!at91_gpio->regbase) {
+ pr_err("at91_gpio.%d, failed to map registers, ignoring.\n", i);
+ return;
+ }
+
+ if (at91_gpio_setup_clk(i))
+ goto ioremap_err;
+
+ gpio_banks = max(gpio_banks, i + 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->id = data[i].id;
- 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);
-
- /* AT91SAM9263_ID_PIOCDE groups PIOC, PIOD, PIOE */
+ /*
+ * GPIO controller are grouped on some SoC:
+ * PIOC, PIOD and PIOE can share the same IRQ line
+ */
if (last && last->id == at91_gpio->id)
last->next = at91_gpio;
last = at91_gpio;
--
1.7.5.4
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