[PATCH v5 3/9] pinctrl: axp209: add pinctrl features

Quentin Schulz
2017-12-05T14:46:41Z

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@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
drivers/pinctrl/pinctrl-axp209.c | 304 ++++++++++++++++++++++++++++++++++++---
1 file changed, 284 insertions(+), 20 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-axp209.c b/drivers/pinctrl/pinctrl-axp209.c
index 6ee7dc1418fa..48cb57dcc575 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@free-electrons.com>
+ * Copyright (C) 2017 Quentin Schulz <quentin.schulz@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
@@ -18,6 +19,9 @@
#include <linux/mfd/axp20x.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
@@ -27,9 +31,52 @@
#define AXP20X_GPIO_FUNCTION_OUT_HIGH 1
#define AXP20X_GPIO_FUNCTION_INPUT 2

+#define AXP20X_FUNC_GPIO_OUT 0
+#define AXP20X_FUNC_GPIO_IN 1
+#define AXP20X_FUNC_LDO 2
+#define AXP20X_FUNC_ADC 3
+#define AXP20X_FUNCS_NB 4
+
+#define AXP20X_MUX_GPIO_OUT 0
+#define AXP20X_MUX_GPIO_IN BIT(1)
+#define AXP20X_MUX_ADC BIT(2)
+
+struct axp20x_pctrl_desc {
+ const struct pinctrl_pin_desc *pins;
+ unsigned int npins;
+ /* Stores the pins supporting LDO function. Bit offset is pin number. */
+ u8 ldo_mask;
+ /* Stores the pins supporting ADC function. Bit offset is pin number. */
+ u8 adc_mask;
+};
+
+struct axp20x_pinctrl_function {
+ const char *name;
+ unsigned int muxval;
+ 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_pctrl_desc *desc;
+ struct axp20x_pinctrl_function funcs[AXP20X_FUNCS_NB];
+};
+
+static const struct pinctrl_pin_desc axp209_pins[] = {
+ PINCTRL_PIN(0, "GPIO0"),
+ PINCTRL_PIN(1, "GPIO1"),
+ PINCTRL_PIN(2, "GPIO2"),
+};
+
+static const struct axp20x_pctrl_desc axp20x_data = {
+ .pins = axp209_pins,
+ .npins = ARRAY_SIZE(axp209_pins),
+ .ldo_mask = BIT(0) | BIT(1),
+ .adc_mask = BIT(0) | BIT(1),
};

static int axp20x_gpio_get_reg(unsigned int offset)
@@ -48,16 +95,7 @@ static int axp20x_gpio_get_reg(unsigned int offset)

static int axp20x_gpio_input(struct gpio_chip *chip, unsigned int 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 int offset)
@@ -105,30 +143,221 @@ static int axp20x_gpio_get_direction(struct gpio_chip *chip,

static int axp20x_gpio_output(struct gpio_chip *chip, unsigned int offset,
int value)
+{
+ chip->set(chip, offset, value);
+
+ return 0;
+}
+
+static void axp20x_gpio_set(struct gpio_chip *chip, unsigned int 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 int offset,
- int value)
+static int axp20x_pmx_func_cnt(struct pinctrl_dev *pctldev)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ return ARRAY_SIZE(gpio->funcs);
+}
+
+static const char *axp20x_pmx_func_name(struct pinctrl_dev *pctldev,
+ unsigned int selector)
+{
+ struct axp20x_gpio *gpio = pinctrl_dev_get_drvdata(pctldev);
+
+ return gpio->funcs[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->funcs[selector].groups;
+ *num_groups = gpio->funcs[selector].ngroups;
+
+ return 0;
+}
+
+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);
+ unsigned int mask;
+
+ /* Every pin supports GPIO_OUT and GPIO_IN functions */
+ if (function <= AXP20X_FUNC_GPIO_IN)
+ return axp20x_pmx_set(pctldev, group,
+ gpio->funcs[function].muxval);
+
+ if (function == AXP20X_FUNC_LDO)
+ mask = gpio->desc->ldo_mask;
+ else
+ mask = gpio->desc->adc_mask;
+
+ if (!(BIT(group) & mask))
+ return -EINVAL;
+
+ /*
+ * We let the regulator framework handle the LDO muxing as muxing bits
+ * are basically also regulators on/off bits. It's better not to enforce
+ * any state of the regulator when selecting LDO mux so that we don't
+ * interfere with the regulator driver.
+ */
+ if (function == AXP20X_FUNC_LDO)
+ return 0;
+
+ return axp20x_pmx_set(pctldev, group, gpio->funcs[function].muxval);
+}
+
+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);
+
+ if (input)
+ return axp20x_pmx_set(pctldev, offset,
+ gpio->funcs[AXP20X_FUNC_GPIO_IN].muxval);
+
+ return axp20x_pmx_set(pctldev, offset,
+ gpio->funcs[AXP20X_FUNC_GPIO_OUT].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->desc->npins;
+}
+
+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);
+
+ *pins = (unsigned int *)&gpio->desc->pins[selector];
+ *num_pins = 1;
+
+ return 0;
+}
+
+static const char *axp20x_group_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->desc->pins[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 void axp20x_funcs_groups_from_mask(struct device *dev, unsigned int mask,
+ unsigned int mask_len,
+ struct axp20x_pinctrl_function *func,
+ const struct pinctrl_pin_desc *pins)
+{
+ unsigned long int mask_cpy = mask;
+ const char **group;
+ unsigned int ngroups = hweight8(mask);
+ int bit;
+
+ func->ngroups = ngroups;
+ if (func->ngroups > 0) {
+ func->groups = devm_kzalloc(dev, ngroups * sizeof(const char *),
+ GFP_KERNEL);
+ group = func->groups;
+ for_each_set_bit(bit, &mask_cpy, mask_len) {
+ *group = pins[bit].name;
+ group++;
+ }
+ }
+}
+
+static void axp20x_build_funcs_groups(struct platform_device *pdev)
+{
+ struct axp20x_gpio *gpio = platform_get_drvdata(pdev);
+ int i, pin, npins = gpio->desc->npins;
+
+ gpio->funcs[AXP20X_FUNC_GPIO_OUT].name = "gpio_out";
+ gpio->funcs[AXP20X_FUNC_GPIO_OUT].muxval = AXP20X_MUX_GPIO_OUT;
+ gpio->funcs[AXP20X_FUNC_GPIO_IN].name = "gpio_in";
+ gpio->funcs[AXP20X_FUNC_GPIO_IN].muxval = AXP20X_MUX_GPIO_IN;
+ gpio->funcs[AXP20X_FUNC_LDO].name = "ldo";
+ /*
+ * Muxval for LDO is useless as we won't use it.
+ * See comment in axp20x_pmx_set_mux.
+ */
+ gpio->funcs[AXP20X_FUNC_ADC].name = "adc";
+ gpio->funcs[AXP20X_FUNC_ADC].muxval = AXP20X_MUX_ADC;
+
+ /* Every pin supports GPIO_OUT and GPIO_IN functions */
+ for (i = 0; i <= AXP20X_FUNC_GPIO_IN; i++) {
+ gpio->funcs[i].ngroups = npins;
+ gpio->funcs[i].groups = devm_kzalloc(&pdev->dev,
+ npins * sizeof(char *),
+ GFP_KERNEL);
+ for (pin = 0; pin < npins; pin++)
+ gpio->funcs[i].groups[pin] = gpio->desc->pins[pin].name;
+ }
+
+ axp20x_funcs_groups_from_mask(&pdev->dev, gpio->desc->ldo_mask,
+ npins, &gpio->funcs[AXP20X_FUNC_LDO],
+ gpio->desc->pins);
+
+ axp20x_funcs_groups_from_mask(&pdev->dev, gpio->desc->adc_mask,
+ npins, &gpio->funcs[AXP20X_FUNC_ADC],
+ gpio->desc->pins);
}

static int axp20x_gpio_probe(struct platform_device *pdev)
{
struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
struct axp20x_gpio *gpio;
+ struct pinctrl_desc *pctrl_desc;
int ret;

if (!of_device_is_available(pdev->dev.of_node))
@@ -145,6 +374,8 @@ 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;
@@ -155,7 +386,30 @@ static int axp20x_gpio_probe(struct platform_device *pdev)
gpio->chip.direction_output = axp20x_gpio_output;
gpio->chip.ngpio = 3;

+ gpio->desc = &axp20x_data;
gpio->regmap = axp20x->regmap;
+ gpio->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, gpio);
+
+ axp20x_build_funcs_groups(pdev);
+
+ 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 = gpio->desc->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) {
@@ -163,7 +417,16 @@ static int axp20x_gpio_probe(struct platform_device *pdev)
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->number,
+ gpio->desc->pins->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;
}
@@ -185,5 +448,6 @@ static struct platform_driver axp20x_gpio_driver = {
module_platform_driver(axp20x_gpio_driver);

MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
-MODULE_DESCRIPTION("AXP20x PMIC GPIO driver");
+MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
+MODULE_DESCRIPTION("AXP20x PMIC pinctrl and GPIO driver");
MODULE_LICENSE("GPL");
--
2.14.1