[PATCH v2 02/10] pinctrl: axp209: add pinctrl features

From: Quentin Schulz
Date: Tue Sep 26 2017 - 08:20:07 EST


The X-Powers AXP209 has 3 GPIOs. GPIO0/1 can each act either as a GPIO,
an ADC or a LDO regulator. GPIO2 can only act as a GPIO.

This adds the pinctrl features to the driver so GPIO0/1 can be used as
ADC or LDO regulator.

Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/pinctrl/pinctrl-axp209.txt | 28 +-
drivers/pinctrl/pinctrl-axp209.c | 462 ++++++-
2 files changed, 468 insertions(+), 22 deletions(-)

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-axp209.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-axp209.txt
index a661130..a5bfe87 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-axp209.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-axp209.txt
@@ -1,4 +1,4 @@
-AXP209 GPIO controller
+AXP209 GPIO & pinctrl controller

This driver follows the usual GPIO bindings found in
Documentation/devicetree/bindings/gpio/gpio.txt
@@ -28,3 +28,29 @@ axp209: pmic@34 {
#gpio-cells = <2>;
};
};
+
+The GPIOs can be muxed to other functions and therefore, must be a subnode of
+axp_gpio.
+
+Example:
+
+&axp_gpio {
+ gpio0_adc: gpio0_adc {
+ pin = "GPIO0";
+ function = "adc";
+ };
+};
+
+&example_node {
+ pinctrl-names = "default";
+ pinctrl-0 = <&gpio0_adc>;
+};
+
+GPIOs and their functions
+-------------------------
+
+GPIO | Functions
+------------------------
+GPIO0 | gpio_in, gpio_out, ldo, adc
+GPIO1 | gpio_in, gpio_out, ldo, adc
+GPIO2 | gpio_in, gpio_out
diff --git a/drivers/pinctrl/pinctrl-axp209.c b/drivers/pinctrl/pinctrl-axp209.c
index 4a346b7..b35e8dd 100644
--- a/drivers/pinctrl/pinctrl-axp209.c
+++ b/drivers/pinctrl/pinctrl-axp209.c
@@ -1,7 +1,8 @@
/*
- * AXP20x GPIO driver
+ * AXP20x pinctrl and GPIO driver
*
* Copyright (C) 2016 Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
+ * Copyright (C) 201 Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
*
* 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
@@ -22,14 +23,92 @@
#include <linux/regmap.h>
#include <linux/slab.h>

+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf-generic.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

+#define AXP20X_PINCTRL_PIN(_pin_num, _pin) \
+ { \
+ .number = _pin_num, \
+ .name = _pin, \
+ }
+
+#define AXP20X_PIN(_pin, ...) \
+ { \
+ .pin = _pin, \
+ .functions = (struct axp20x_desc_function[]) { \
+ __VA_ARGS__, { } }, \
+ }
+
+#define AXP20X_FUNCTION(_val, _name) \
+ { \
+ .name = _name, \
+ .muxval = _val, \
+ }
+
+struct axp20x_desc_function {
+ const char *name;
+ u8 muxval;
+};
+
+struct axp20x_desc_pin {
+ struct pinctrl_pin_desc pin;
+ struct axp20x_desc_function *functions;
+};
+
+struct axp20x_pinctrl_desc {
+ const struct axp20x_desc_pin *pins;
+ int npins;
+};
+
+struct axp20x_pinctrl_group {
+ const char *name;
+ unsigned long config;
+ unsigned int pin;
+};
+
+struct axp20x_pinctrl_function {
+ const char *name;
+ const char **groups;
+ unsigned int ngroups;
+};
+
struct axp20x_gpio {
struct gpio_chip chip;
struct regmap *regmap;
+ struct pinctrl_dev *pctl_dev;
+ struct device *dev;
+ const struct axp20x_pinctrl_desc *desc;
+ struct axp20x_pinctrl_group *groups;
+ unsigned int ngroups;
+ struct axp20x_pinctrl_function *functions;
+ unsigned int nfunctions;
+};
+
+static const struct axp20x_desc_pin axp209_pins[] = {
+ AXP20X_PIN(AXP20X_PINCTRL_PIN(0, "GPIO0"),
+ AXP20X_FUNCTION(0x0, "gpio_out"),
+ AXP20X_FUNCTION(0x2, "gpio_in"),
+ AXP20X_FUNCTION(0x3, "ldo"),
+ AXP20X_FUNCTION(0x4, "adc")),
+ AXP20X_PIN(AXP20X_PINCTRL_PIN(1, "GPIO1"),
+ AXP20X_FUNCTION(0x0, "gpio_out"),
+ AXP20X_FUNCTION(0x2, "gpio_in"),
+ AXP20X_FUNCTION(0x3, "ldo"),
+ AXP20X_FUNCTION(0x4, "adc")),
+ AXP20X_PIN(AXP20X_PINCTRL_PIN(2, "GPIO2"),
+ AXP20X_FUNCTION(0x0, "gpio_out"),
+ AXP20X_FUNCTION(0x2, "gpio_in")),
+};
+
+static const struct axp20x_pinctrl_desc axp20x_pinctrl_data = {
+ .pins = axp209_pins,
+ .npins = ARRAY_SIZE(axp209_pins),
};

static int axp20x_gpio_get_reg(unsigned offset)
@@ -48,16 +127,7 @@ static int axp20x_gpio_get_reg(unsigned offset)

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);
+ return pinctrl_gpio_direction_input(chip->base + offset);
}

static int axp20x_gpio_get(struct gpio_chip *chip, unsigned offset)
@@ -105,30 +175,334 @@ static int axp20x_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
static int axp20x_gpio_output(struct gpio_chip *chip, unsigned offset,
int value)
{
+ chip->set(chip, offset, value);
+
+ return 0;
+}
+
+static void axp20x_gpio_set(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;
+
+ regmap_update_bits(gpio->regmap, reg,
+ AXP20X_GPIO_FUNCTIONS,
+ value ? AXP20X_GPIO_FUNCTION_OUT_HIGH :
+ AXP20X_GPIO_FUNCTION_OUT_LOW);
+}
+
+static int axp20x_pmx_set(struct pinctrl_dev *pctldev, unsigned int offset,
+ u8 config)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+ 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);
+ return regmap_update_bits(gpio->regmap, reg, AXP20X_GPIO_FUNCTIONS,
+ config);
}

-static void axp20x_gpio_set(struct gpio_chip *chip, unsigned offset,
- int value)
+static int axp20x_pmx_func_cnt(struct pinctrl_dev *pctldev)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ return gpio->nfunctions;
+}
+
+static const char *axp20x_pmx_func_name(struct pinctrl_dev *pctldev,
+ unsigned int selector)
{
- axp20x_gpio_output(chip, offset, value);
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ return gpio->functions[selector].name;
+}
+
+static int axp20x_pmx_func_groups(struct pinctrl_dev *pctldev,
+ unsigned int selector,
+ const char * const **groups,
+ unsigned int *num_groups)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ *groups = gpio->functions[selector].groups;
+ *num_groups = gpio->functions[selector].ngroups;
+
+ return 0;
+}
+
+static struct axp20x_desc_function *
+axp20x_pinctrl_desc_find_func_by_name(struct axp20x_gpio *gpio,
+ const char *group, const char *func)
+{
+ const struct axp20x_desc_pin *pin;
+ struct axp20x_desc_function *desc_func;
+ int i;
+
+ for (i = 0; i < gpio->desc->npins; i++) {
+ pin = &gpio->desc->pins[i];
+
+ if (!strcmp(pin->pin.name, group)) {
+ desc_func = pin->functions;
+
+ while (desc_func->name) {
+ if (!strcmp(desc_func->name, func))
+ return desc_func;
+ desc_func++;
+ }
+
+ /*
+ * Pins are uniquely named. Groups are named after one
+ * pin name. If one pin matches group name but its
+ * function cannot be found, no other pin will match
+ * group name.
+ */
+ return NULL;
+ }
+ }
+
+ return NULL;
+}
+
+static int axp20x_pmx_set_mux(struct pinctrl_dev *pctldev,
+ unsigned int function, unsigned int group)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+ struct axp20x_pinctrl_group *g = gpio->groups + group;
+ struct axp20x_pinctrl_function *func = gpio->functions + function;
+ struct axp20x_desc_function *desc_func =
+ axp20x_pinctrl_desc_find_func_by_name(gpio, g->name,
+ func->name);
+ if (!desc_func)
+ return -EINVAL;
+
+ return axp20x_pmx_set(pctldev, g->pin, desc_func->muxval);
+}
+
+static struct axp20x_desc_function *
+axp20x_pctl_desc_find_func_by_pin(struct axp20x_gpio *gpio, unsigned int offset,
+ const char *func)
+{
+ const struct axp20x_desc_pin *pin;
+ struct axp20x_desc_function *desc_func;
+ int i;
+
+ for (i = 0; i < gpio->desc->npins; i++) {
+ pin = &gpio->desc->pins[i];
+
+ if (pin->pin.number == offset) {
+ desc_func = pin->functions;
+
+ while (desc_func->name) {
+ if (!strcmp(desc_func->name, func))
+ return desc_func;
+
+ desc_func++;
+ }
+ }
+ }
+
+ return NULL;
+}
+
+static int axp20x_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
+ struct pinctrl_gpio_range *range,
+ unsigned int offset, bool input)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+ struct axp20x_desc_function *desc_func;
+ const char *func;
+
+ if (input)
+ func = "gpio_in";
+ else
+ func = "gpio_out";
+
+ desc_func = axp20x_pctl_desc_find_func_by_pin(gpio, offset, func);
+ if (!desc_func)
+ return -EINVAL;
+
+ return axp20x_pmx_set(pctldev, offset, desc_func->muxval);
+}
+
+static const struct pinmux_ops axp20x_pmx_ops = {
+ .get_functions_count = axp20x_pmx_func_cnt,
+ .get_function_name = axp20x_pmx_func_name,
+ .get_function_groups = axp20x_pmx_func_groups,
+ .set_mux = axp20x_pmx_set_mux,
+ .gpio_set_direction = axp20x_pmx_gpio_set_direction,
+ .strict = true,
+};
+
+static int axp20x_groups_cnt(struct pinctrl_dev *pctldev)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ return gpio->ngroups;
+}
+
+static int axp20x_group_pins(struct pinctrl_dev *pctldev, unsigned int selector,
+ const unsigned int **pins, unsigned int *num_pins)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+ struct axp20x_pinctrl_group *g = gpio->groups + selector;
+
+ *pins = (unsigned int *)&g->pin;
+ *num_pins = 1;
+
+ return 0;
+}
+
+static const char *axp20x_group_name(struct pinctrl_dev *pctldev,
+ unsigned int selector)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ return gpio->groups[selector].name;
+}
+
+static const struct pinctrl_ops axp20x_pctrl_ops = {
+ .dt_node_to_map = pinconf_generic_dt_node_to_map_group,
+ .dt_free_map = pinconf_generic_dt_free_map,
+ .get_groups_count = axp20x_groups_cnt,
+ .get_group_name = axp20x_group_name,
+ .get_group_pins = axp20x_group_pins,
+};
+
+static struct axp20x_pinctrl_function *
+axp20x_pinctrl_function_by_name(struct axp20x_gpio *gpio, const char *name)
+{
+ struct axp20x_pinctrl_function *func = gpio->functions;
+
+ while (func->name) {
+ if (!strcmp(func->name, name))
+ return func;
+ func++;
+ }
+
+ return NULL;
+}
+
+static int axp20x_pinctrl_add_function(struct axp20x_gpio *gpio,
+ const char *name)
+{
+ struct axp20x_pinctrl_function *func = gpio->functions;
+
+ while (func->name) {
+ if (!strcmp(func->name, name)) {
+ func->ngroups++;
+ return -EEXIST;
+ }
+
+ func++;
+ }
+
+ func->name = name;
+ func->ngroups = 1;
+
+ gpio->nfunctions++;
+
+ return 0;
+}
+
+static int axp20x_attach_group_function(struct platform_device *pdev,
+ const struct axp20x_desc_pin *pin)
+{
+ struct axp20x_gpio *gpio = platform_get_drvdata(pdev);
+ struct axp20x_desc_function *desc_func = pin->functions;
+ struct axp20x_pinctrl_function *func;
+ const char **func_grp;
+
+ while (desc_func->name) {
+ func = axp20x_pinctrl_function_by_name(gpio, desc_func->name);
+ if (!func)
+ return -EINVAL;
+
+ if (!func->groups) {
+ func->groups = devm_kzalloc(&pdev->dev,
+ func->ngroups * sizeof(const char *),
+ GFP_KERNEL);
+ if (!func->groups)
+ return -ENOMEM;
+ }
+
+ func_grp = func->groups;
+ while (*func_grp)
+ func_grp++;
+
+ *func_grp = pin->pin.name;
+ desc_func++;
+ }
+
+ return 0;
+}
+
+static int axp20x_build_state(struct platform_device *pdev)
+{
+ struct axp20x_gpio *gpio = platform_get_drvdata(pdev);
+ unsigned int npins = gpio->desc->npins;
+ const struct axp20x_desc_pin *pin;
+ struct axp20x_desc_function *func;
+ int i, ret;
+
+ gpio->ngroups = npins;
+ gpio->groups = devm_kzalloc(&pdev->dev,
+ gpio->ngroups * sizeof(*gpio->groups),
+ GFP_KERNEL);
+ if (!gpio->groups)
+ return -ENOMEM;
+
+ for (i = 0; i < npins; i++) {
+ gpio->groups[i].name = gpio->desc->pins[i].pin.name;
+ gpio->groups[i].pin = gpio->desc->pins[i].pin.number;
+ }
+
+ /* We assume 4 functions per pin should be enough as a default max */
+ gpio->functions = devm_kzalloc(&pdev->dev,
+ npins * 4 * sizeof(*gpio->functions),
+ GFP_KERNEL);
+ if (!gpio->functions)
+ return -ENOMEM;
+
+ /* Create a list of uniquely named functions */
+ for (i = 0; i < npins; i++) {
+ pin = &gpio->desc->pins[i];
+ func = pin->functions;
+
+ while (func->name) {
+ axp20x_pinctrl_add_function(gpio, func->name);
+ func++;
+ }
+ }
+
+ gpio->functions = krealloc(gpio->functions,
+ gpio->nfunctions * sizeof(*gpio->functions),
+ GFP_KERNEL);
+
+ for (i = 0; i < npins; i++) {
+ pin = &gpio->desc->pins[i];
+ ret = axp20x_attach_group_function(pdev, pin);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}

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;
+ struct pinctrl_desc *pctrl_desc;
+ struct pinctrl_pin_desc *pins;
+ int ret, i;

if (!of_device_is_available(pdev->dev.of_node))
return -ENODEV;
@@ -144,6 +518,8 @@ static int axp20x_gpio_probe(struct platform_device *pdev)

gpio->chip.base = -1;
gpio->chip.can_sleep = true;
+ gpio->chip.request = gpiochip_generic_request;
+ gpio->chip.free = gpiochip_generic_free;
gpio->chip.parent = &pdev->dev;
gpio->chip.label = dev_name(&pdev->dev);
gpio->chip.owner = THIS_MODULE;
@@ -156,13 +532,56 @@ static int axp20x_gpio_probe(struct platform_device *pdev)

gpio->regmap = axp20x->regmap;

+ gpio->desc = &axp20x_pinctrl_data;
+ gpio->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, gpio);
+
+ ret = axp20x_build_state(pdev);
+ if (ret)
+ return ret;
+
+ pins = devm_kzalloc(&pdev->dev, gpio->desc->npins * sizeof(*pins),
+ GFP_KERNEL);
+ if (!pins)
+ return -ENOMEM;
+
+ for (i = 0; i < gpio->desc->npins; i++)
+ pins[i] = gpio->desc->pins[i].pin;
+
+ pctrl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctrl_desc), GFP_KERNEL);
+ if (!pctrl_desc)
+ return -ENOMEM;
+
+ pctrl_desc->name = dev_name(&pdev->dev);
+ pctrl_desc->owner = THIS_MODULE;
+ pctrl_desc->pins = pins;
+ pctrl_desc->npins = gpio->desc->npins;
+ pctrl_desc->pctlops = &axp20x_pctrl_ops;
+ pctrl_desc->pmxops = &axp20x_pmx_ops;
+
+ gpio->pctl_dev = devm_pinctrl_register(&pdev->dev, pctrl_desc, gpio);
+ if (IS_ERR(gpio->pctl_dev)) {
+ dev_err(&pdev->dev, "couldn't register pinctrl driver\n");
+ return PTR_ERR(gpio->pctl_dev);
+ }
+
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");
+ ret = gpiochip_add_pin_range(&gpio->chip, dev_name(&pdev->dev),
+ gpio->desc->pins->pin.number,
+ gpio->desc->pins->pin.number,
+ gpio->desc->npins);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to add pin range\n");
+ return ret;
+ }
+
+ dev_info(&pdev->dev, "AXP209 pinctrl and GPIO driver loaded\n");

return 0;
}
@@ -184,5 +603,6 @@ static struct platform_driver axp20x_gpio_driver = {
module_platform_driver(axp20x_gpio_driver);

MODULE_AUTHOR("Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("AXP20x PMIC GPIO driver");
+MODULE_AUTHOR("Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("AXP20x PMIC pinctrl and GPIO driver");
MODULE_LICENSE("GPL");
--
git-series 0.9.1