ARM: sunxi: gpio: Add Allwinner SoCs GPIO drivers

The IP responsible for the muxing on the Allwinner SoCs are also
handling the GPIOs on the system. This patch adds the needed driver that
relies on the pinctrl driver for most of its operations.

The number of pins available for GPIOs operations are already declared
in the pinctrl driver, we only need to probe a generic driver to handle
the banks available for each SoC.

This driver has been tested on a A13-Olinuxino.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 132 insertions, 2 deletions

diff --git a/drivers/pinctrl/pinctrl-sunxi.c b/drivers/pinctrl/pinctrl-sunxi.c
index 6f02e3422af9..fb000b00c6d3 100644
--- a/drivers/pinctrl/pinctrl-sunxi.c
+++ b/drivers/pinctrl/pinctrl-sunxi.c
@@ -11,6 +11,7 @@
  */
 
 #include <linux/io.h>
+#include <linux/gpio.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
@@ -609,11 +610,53 @@ static int sunxi_pmx_enable(struct pinctrl_dev *pctldev,
         return 0;
 }
 
+static int
+sunxi_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
+                        struct pinctrl_gpio_range *range,
+                        unsigned offset,
+                        bool input)
+{
+        struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
+        struct sunxi_desc_function *desc;
+        char pin_name[SUNXI_PIN_NAME_MAX_LEN];
+        const char *func;
+        u8 bank, pin;
+        int ret;
+
+        bank = (offset) / PINS_PER_BANK;
+        pin = (offset) % PINS_PER_BANK;
+
+        ret = sprintf(pin_name, "P%c%d", 'A' + bank, pin);
+        if (!ret)
+                goto error;
+
+        if (input)
+                func = "gpio_in";
+        else
+                func = "gpio_out";
+
+        desc = sunxi_pinctrl_desc_find_function_by_name(pctl,
+                                                        pin_name,
+                                                        func);
+        if (!desc) {
+                ret = -EINVAL;
+                goto error;
+        }
+
+        sunxi_pmx_set(pctldev, offset, desc->muxval);
+
+        ret = 0;
+
+error:
+        return ret;
+}
+
 static struct pinmux_ops sunxi_pmx_ops = {
         .get_functions_count    = sunxi_pmx_get_funcs_cnt,
         .get_function_name      = sunxi_pmx_get_func_name,
         .get_function_groups    = sunxi_pmx_get_func_groups,
         .enable                 = sunxi_pmx_enable,
+        .gpio_set_direction     = sunxi_pmx_gpio_set_direction,
 };
 
 static struct pinctrl_desc sunxi_pctrl_desc = {
@@ -622,6 +665,60 @@ static struct pinctrl_desc sunxi_pctrl_desc = {
         .pmxops         = &sunxi_pmx_ops,
 };
 
+static int sunxi_pinctrl_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+        return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void sunxi_pinctrl_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+        pinctrl_free_gpio(chip->base + offset);
+}
+
+static int sunxi_pinctrl_gpio_direction_input(struct gpio_chip *chip,
+                                        unsigned offset)
+{
+        return pinctrl_gpio_direction_input(chip->base + offset);
+}
+
+static int sunxi_pinctrl_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct sunxi_pinctrl *pctl = dev_get_drvdata(chip->dev);
+
+        u32 reg = sunxi_data_reg(offset);
+        u8 index = sunxi_data_offset(offset);
+        u32 val = (readl(pctl->membase + reg) >> index) & DATA_PINS_MASK;
+
+        return val;
+}
+
+static int sunxi_pinctrl_gpio_direction_output(struct gpio_chip *chip,
+                                        unsigned offset, int value)
+{
+        return pinctrl_gpio_direction_output(chip->base + offset);
+}
+
+static void sunxi_pinctrl_gpio_set(struct gpio_chip *chip,
+                                unsigned offset, int value)
+{
+        struct sunxi_pinctrl *pctl = dev_get_drvdata(chip->dev);
+        u32 reg = sunxi_data_reg(offset);
+        u8 index = sunxi_data_offset(offset);
+
+        writel((value & DATA_PINS_MASK) << index, pctl->membase + reg);
+}
+
+static struct gpio_chip sunxi_pinctrl_gpio_chip = {
+        .owner                  = THIS_MODULE,
+        .request                = sunxi_pinctrl_gpio_request,
+        .free                   = sunxi_pinctrl_gpio_free,
+        .direction_input        = sunxi_pinctrl_gpio_direction_input,
+        .direction_output       = sunxi_pinctrl_gpio_direction_output,
+        .get                    = sunxi_pinctrl_gpio_get,
+        .set                    = sunxi_pinctrl_gpio_set,
+        .can_sleep              = 0,
+};
+
 static struct of_device_id sunxi_pinctrl_match[] = {
         { .compatible = "allwinner,sun5i-a13-pinctrl", .data = (void *)&sun5i_a13_pinctrl_data },
         {}
@@ -737,7 +834,7 @@ static int sunxi_pinctrl_probe(struct platform_device *pdev)
         const struct of_device_id *device;
         struct pinctrl_pin_desc *pins;
         struct sunxi_pinctrl *pctl;
-        int i, ret;
+        int i, ret, last_pin;
 
         pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
         if (!pctl)
@@ -781,9 +878,42 @@ static int sunxi_pinctrl_probe(struct platform_device *pdev)
                 return -EINVAL;
         }
 
-        dev_info(&pdev->dev, "initialized sunXi pin control driver\n");
+        pctl->chip = devm_kzalloc(&pdev->dev, sizeof(*pctl->chip), GFP_KERNEL);
+        if (!pctl->chip) {
+                ret = -ENOMEM;
+                goto pinctrl_error;
+        }
+
+        last_pin = pctl->desc->pins[pctl->desc->npins - 1].pin.number;
+        pctl->chip = &sunxi_pinctrl_gpio_chip;
+        pctl->chip->ngpio = round_up(last_pin, PINS_PER_BANK);
+        pctl->chip->label = dev_name(&pdev->dev);
+        pctl->chip->dev = &pdev->dev;
+        pctl->chip->base = 0;
+
+        ret = gpiochip_add(pctl->chip);
+        if (ret)
+                goto pinctrl_error;
+
+        for (i = 0; i < pctl->desc->npins; i++) {
+                const struct sunxi_desc_pin *pin = pctl->desc->pins + i;
+
+                ret = gpiochip_add_pin_range(pctl->chip, dev_name(&pdev->dev),
+                                             pin->pin.number,
+                                             pin->pin.number, 1);
+                if (ret)
+                        goto gpiochip_error;
+        }
+
+        dev_info(&pdev->dev, "initialized sunXi PIO driver\n");
 
         return 0;
+
+gpiochip_error:
+        ret = gpiochip_remove(pctl->chip);
+pinctrl_error:
+        pinctrl_unregister(pctl->pctl_dev);
+        return ret;
 }
 
 static struct platform_driver sunxi_pinctrl_driver = {