pinctrl: axp209: add pinctrl features

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>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files 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)
@@ -106,29 +144,220 @@ 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");