[PATCH v2 0/4] Add AXP209 GPIO driver

[PATCH v2 0/4] Add AXP209 GPIO driver

[Maxime Ripard]

Hi,

The axp209 PMIC used in combination to some Allwinner SoCs has a bunch
of GPIOs accessible. Some boards use these to control their backlight
or a few LEDs.

There's supposed to be 4 of them, but the fourth one has a different
configuration register scheme, and I couldn't find any board that was
using this GPIO. It will be probably be supported eventually, but
until then, we support only the first 3 GPIOs.

Let me know what you think,
Maxime

Changes from v1:
  - Use gpiochip_add_data and gpiochip_get_data
  - Drop unneeded headers
  - Make sure gpio_get returns 0 or 1
  - Made sure it compiles
  - Rebased on linux-next

Maxime Ripard (4):
  gpio: Add AXP209 GPIO driver
  mfd: axp20x: Add AXP209 GPIO driver to the mfd
  ARM: dt: axp209: Add AXP209 GPIO driver
  ARM: sun5i: chip: Add status LED

 .../devicetree/bindings/gpio/gpio-axp209.txt       |  30 ++++
 arch/arm/boot/dts/axp209.dtsi                      |   6 +
 arch/arm/boot/dts/sun5i-r8-chip.dts                |  10 ++
 drivers/gpio/Kconfig                               |   6 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-axp209.c                         | 162 +++++++++++++++++++++
 drivers/mfd/axp20x.c                               |   3 +
 7 files changed, 218 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-axp209.txt
 create mode 100644 drivers/gpio/gpio-axp209.c

-- 
2.9.0

[PATCH v2 1/4] gpio: Add AXP209 GPIO driver

[Maxime Ripard]

The AXP209 PMIC has a bunch of GPIOs accessible, that are usually used to
control LEDs or backlight.

Add a driver for them

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/gpio/gpio-axp209.txt       |  30 ++++
 drivers/gpio/Kconfig                               |   6 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-axp209.c                         | 162 +++++++++++++++++++++
 4 files changed, 199 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-axp209.txt
 create mode 100644 drivers/gpio/gpio-axp209.c

diff --git a/Documentation/devicetree/bindings/gpio/gpio-axp209.txt b/Documentation/devicetree/bindings/gpio/gpio-axp209.txt
new file mode 100644
index 000000000000..a6611304dd3c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-axp209.txt
@@ -0,0 +1,30 @@
+AXP209 GPIO controller
+
+This driver follows the usual GPIO bindings found in
+Documentation/devicetree/bindings/gpio/gpio.txt
+
+Required properties:
+- compatible: Should be "x-powers,axp209-gpio"
+- #gpio-cells: Should be two. The first cell is the pin number and the
+  second is the GPIO flags.
+- gpio-controller: Marks the device node as a GPIO controller.
+
+This node must be a subnode of the axp20x PMIC, documented in
+Documentation/devicetree/bindings/mfd/axp20x.txt
+
+Example:
+
+axp209: pmic@34 {
+	compatible = "x-powers,axp209";
+	reg = <0x34>;
+	interrupt-parent = <&nmi_intc>;
+	interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
+	interrupt-controller;
+	#interrupt-cells = <1>;
+
+	axp_gpio: gpio {
+		compatible = "x-powers,axp209-gpio";
+		gpio-controller;
+		#gpio-cells = <2>;
+	};
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 98dd47a30fc7..7d8995b88330 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -137,6 +137,12 @@ config GPIO_ATH79
 	  Select this option to enable GPIO driver for
 	  Atheros AR71XX/AR724X/AR913X SoC devices.
 
+config GPIO_AXP209
+	tristate "X-Powers AXP209 PMIC GPIO Support"
+	depends on MFD_AXP20X
+	help
+	  Say yes to enable GPIO support for the AXP209 PMIC
+
 config GPIO_BCM_KONA
 	bool "Broadcom Kona GPIO"
 	depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 2a035ed8f168..b7d509e27ed1 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
 obj-$(CONFIG_GPIO_AMDPT)	+= gpio-amdpt.o
 obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
 obj-$(CONFIG_GPIO_ATH79)	+= gpio-ath79.o
+obj-$(CONFIG_GPIO_AXP209)	+= gpio-axp209.o
 obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o
 obj-$(CONFIG_GPIO_BRCMSTB)	+= gpio-brcmstb.o
 obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-axp209.c b/drivers/gpio/gpio-axp209.c
new file mode 100644
index 000000000000..3174799c27c6
--- /dev/null
+++ b/drivers/gpio/gpio-axp209.c
@@ -0,0 +1,162 @@
+/*
+ * AXP20x GPIO driver
+ *
+ * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under  the terms of the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define AXP20X_GPIO_FUNCTIONS		0x7
+#define AXP20X_GPIO_FUNCTION_OUT_LOW	0
+#define AXP20X_GPIO_FUNCTION_OUT_HIGH	1
+#define AXP20X_GPIO_FUNCTION_INPUT	2
+
+struct axp20x_gpio {
+	struct gpio_chip	chip;
+	struct regmap		*regmap;
+};
+
+static int axp20x_gpio_get_reg(unsigned offset)
+{
+	switch (offset) {
+	case 0:
+		return AXP20X_GPIO0_CTRL;
+	case 1:
+		return AXP20X_GPIO1_CTRL;
+	case 2:
+		return AXP20X_GPIO2_CTRL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp20x_gpio_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct axp20x_gpio *gpio = gpiochip_get_data(chip);
+	int reg;
+
+	reg = axp20x_gpio_get_reg(offset);
+	if (reg < 0)
+		return reg;
+
+	return regmap_update_bits(gpio->regmap, reg,
+				  AXP20X_GPIO_FUNCTIONS,
+				  AXP20X_GPIO_FUNCTION_INPUT);
+}
+
+static int axp20x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct axp20x_gpio *gpio = gpiochip_get_data(chip);
+	unsigned int val;
+	int reg, ret;
+
+	reg = axp20x_gpio_get_reg(offset);
+	if (reg < 0)
+		return reg;
+
+	ret = regmap_read(gpio->regmap, reg, &val);
+	if (ret)
+		return ret;
+
+	return !!(val & BIT(offset + 4));
+}
+
+static int axp20x_gpio_output(struct gpio_chip *chip, unsigned offset,
+			      int value)
+{
+	struct axp20x_gpio *gpio = gpiochip_get_data(chip);
+	int reg;
+
+	reg = axp20x_gpio_get_reg(offset);
+	if (reg < 0)
+		return reg;
+
+	return regmap_update_bits(gpio->regmap, reg,
+				  AXP20X_GPIO_FUNCTIONS,
+				  value ? AXP20X_GPIO_FUNCTION_OUT_HIGH
+				  : AXP20X_GPIO_FUNCTION_OUT_LOW);
+}
+
+static void axp20x_gpio_set(struct gpio_chip *chip, unsigned offset,
+			    int value)
+{
+	axp20x_gpio_output(chip, offset, value);
+}
+
+static int axp20x_gpio_probe(struct platform_device *pdev)
+{
+	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
+	struct axp20x_gpio *gpio;
+	int ret;
+
+	if (!of_device_is_available(pdev->dev.of_node))
+		return -ENODEV;
+
+	if (!axp20x) {
+		dev_err(&pdev->dev, "Parent drvdata not set\n");
+		return -EINVAL;
+	}
+
+	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+	if (!gpio)
+		return -ENOMEM;
+
+	gpio->chip.base			= -1;
+	gpio->chip.can_sleep		= true;
+	gpio->chip.parent		= &pdev->dev;
+	gpio->chip.label		= dev_name(&pdev->dev);
+	gpio->chip.owner		= THIS_MODULE;
+	gpio->chip.get			= axp20x_gpio_get;
+	gpio->chip.set			= axp20x_gpio_set;
+	gpio->chip.direction_input	= axp20x_gpio_input;
+	gpio->chip.direction_output	= axp20x_gpio_output;
+	gpio->chip.ngpio		= 3;
+
+	gpio->regmap = axp20x->regmap;
+
+	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register GPIO chip\n");
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "AXP209 GPIO driver loaded\n");
+
+	return 0;
+}
+
+static const struct of_device_id axp20x_gpio_match[] = {
+	{ .compatible = "x-powers,axp209-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, axp20x_gpio_match);
+
+static struct platform_driver axp20x_gpio_driver = {
+	.probe		= axp20x_gpio_probe,
+	.driver = {
+		.name		= "axp20x-gpio",
+		.of_match_table	= axp20x_gpio_match,
+	},
+};
+
+module_platform_driver(axp20x_gpio_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("AXP20x PMIC GPIO driver");
+MODULE_LICENSE("GPL");
-- 
2.9.0

[PATCH v2 2/4] mfd: axp20x: Add AXP209 GPIO driver to the mfd

[Maxime Ripard]

Now that we have a GPIO driver for the AXP209, we can add it to our MFD.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mfd/axp20x.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
index fd80b0981f0f..4b3e073c47b7 100644
--- a/drivers/mfd/axp20x.c
+++ b/drivers/mfd/axp20x.c
@@ -508,6 +508,9 @@ static const struct regmap_irq_chip axp809_regmap_irq_chip = {
 
 static struct mfd_cell axp20x_cells[] = {
 	{
+		.name		= "axp20x-gpio",
+		.of_compatible	= "x-powers,axp209-gpio",
+	}, {
 		.name		= "axp20x-pek",
 		.num_resources	= ARRAY_SIZE(axp20x_pek_resources),
 		.resources	= axp20x_pek_resources,
-- 
2.9.0

[PATCH v2 3/4] ARM: dt: axp209: Add AXP209 GPIO driver

[Maxime Ripard]

Add the AXP209 GPIO node to our AXP209 DTSI so that boards can use it.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 arch/arm/boot/dts/axp209.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/axp209.dtsi b/arch/arm/boot/dts/axp209.dtsi
index afbe89c01df5..675bb0f30825 100644
--- a/arch/arm/boot/dts/axp209.dtsi
+++ b/arch/arm/boot/dts/axp209.dtsi
@@ -53,6 +53,12 @@
 	interrupt-controller;
 	#interrupt-cells = <1>;
 
+	axp_gpio: gpio {
+		compatible = "x-powers,axp209-gpio";
+		gpio-controller;
+		#gpio-cells = <2>;
+	};
+
 	regulators {
 		/* Default work frequency for buck regulators */
 		x-powers,dcdc-freq = <1500>;
-- 
2.9.0

[PATCH v2 4/4] ARM: sun5i: chip: Add status LED

[Maxime Ripard]

The CHIP has a status LED connected to one of the AXP GPIOs. Add the
gpio-leds node to be able to use the proper LED framework to control it.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-r8-chip.dts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/sun5i-r8-chip.dts b/arch/arm/boot/dts/sun5i-r8-chip.dts
index f694482bdeb6..b68a12374b35 100644
--- a/arch/arm/boot/dts/sun5i-r8-chip.dts
+++ b/arch/arm/boot/dts/sun5i-r8-chip.dts
@@ -64,6 +64,16 @@
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		status {
+			label = "chip:white:status";
+			gpios = <&axp_gpio 2 GPIO_ACTIVE_HIGH>;
+			default-state = "on";
+		};
+	};
 };
 
 &be0 {
-- 
2.9.0

Re: [PATCH v2 2/4] mfd: axp20x: Add AXP209 GPIO driver to the mfd

[Lee Jones]

On Wed, 20 Jul 2016, Maxime Ripard wrote:

> Now that we have a GPIO driver for the AXP209, we can add it to our MFD.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/mfd/axp20x.c | 3 +++
>  1 file changed, 3 insertions(+)

Applied, thanks.

> diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> index fd80b0981f0f..4b3e073c47b7 100644
> --- a/drivers/mfd/axp20x.c
> +++ b/drivers/mfd/axp20x.c
> @@ -508,6 +508,9 @@ static const struct regmap_irq_chip axp809_regmap_irq_chip = {
>  
>  static struct mfd_cell axp20x_cells[] = {
>  	{
> +		.name		= "axp20x-gpio",
> +		.of_compatible	= "x-powers,axp209-gpio",
> +	}, {
>  		.name		= "axp20x-pek",
>  		.num_resources	= ARRAY_SIZE(axp20x_pek_resources),
>  		.resources	= axp20x_pek_resources,

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v2 1/4] gpio: Add AXP209 GPIO driver

[Linus Walleij]

On Wed, Jul 20, 2016 at 4:11 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:

> The AXP209 PMIC has a bunch of GPIOs accessible, that are usually used to
> control LEDs or backlight.
>
> Add a driver for them
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> Acked-by: Rob Herring <robh@kernel.org>

Patch applied, it's clean and simple. I would suggest the
following immediate improvement (send separate patch):

Add a .get_direction() callback, I have started to push this
for new driver as it gives better userspace experience
and overall better control of stuff.

Yours,
Linus Walleij

Re: [PATCH v2 0/4] Add AXP209 GPIO driver

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 655 bytes --]

On Wed, Jul 20, 2016 at 04:11:35PM +0200, Maxime Ripard wrote:
> Hi,
> 
> The axp209 PMIC used in combination to some Allwinner SoCs has a bunch
> of GPIOs accessible. Some boards use these to control their backlight
> or a few LEDs.
> 
> There's supposed to be 4 of them, but the fourth one has a different
> configuration register scheme, and I couldn't find any board that was
> using this GPIO. It will be probably be supported eventually, but
> until then, we support only the first 3 GPIOs.

I merged the patches 3 and 4.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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