gpio: tegra186: Add support for pin ranges

Add support for Tegra SoC generations to specify a list of pin ranges
that map GPIOs to ranges of pins in the pin controller.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200319122737.3063291-3-thierry.reding@gmail.com
Tested-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-tegra186.c

@@ -58,11 +58,20 @@ struct tegra_gpio_port {
 	unsigned int pins;
 };
 
+struct tegra186_pin_range {
+	unsigned int offset;
+	const char *group;
+};
+
 struct tegra_gpio_soc {
 	const struct tegra_gpio_port *ports;
 	unsigned int num_ports;
 	const char *name;
 	unsigned int instance;
+
+	const struct tegra186_pin_range *pin_ranges;
+	unsigned int num_pin_ranges;
+	const char *pinmux;
 };
 
 struct tegra_gpio {
@@ -254,6 +263,50 @@ static int tegra186_gpio_set_config(struct gpio_chip *chip,
 	return 0;
 }
 
+static int tegra186_gpio_add_pin_ranges(struct gpio_chip *chip)
+{
+	struct tegra_gpio *gpio = gpiochip_get_data(chip);
+	struct pinctrl_dev *pctldev;
+	struct device_node *np;
+	unsigned int i, j;
+	int err;
+
+	if (!gpio->soc->pinmux || gpio->soc->num_pin_ranges == 0)
+		return 0;
+
+	np = of_find_compatible_node(NULL, NULL, gpio->soc->pinmux);
+	if (!np)
+		return -ENODEV;
+
+	pctldev = of_pinctrl_get(np);
+	of_node_put(np);
+	if (!pctldev)
+		return -EPROBE_DEFER;
+
+	for (i = 0; i < gpio->soc->num_pin_ranges; i++) {
+		unsigned int pin = gpio->soc->pin_ranges[i].offset, port;
+		const char *group = gpio->soc->pin_ranges[i].group;
+
+		port = pin / 8;
+		pin = pin % 8;
+
+		if (port >= gpio->soc->num_ports) {
+			dev_warn(chip->parent, "invalid port %u for %s\n",
+				 port, group);
+			continue;
+		}
+
+		for (j = 0; j < port; j++)
+			pin += gpio->soc->ports[j].pins;
+
+		err = gpiochip_add_pingroup_range(chip, pctldev, pin, group);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
 static int tegra186_gpio_of_xlate(struct gpio_chip *chip,
 				  const struct of_phandle_args *spec,
 				  u32 *flags)
@@ -578,12 +631,15 @@ static int tegra186_gpio_probe(struct platform_device *pdev)
 	gpio->gpio.label = gpio->soc->name;
 	gpio->gpio.parent = &pdev->dev;
 
+	gpio->gpio.request = gpiochip_generic_request;
+	gpio->gpio.free = gpiochip_generic_free;
 	gpio->gpio.get_direction = tegra186_gpio_get_direction;
 	gpio->gpio.direction_input = tegra186_gpio_direction_input;
 	gpio->gpio.direction_output = tegra186_gpio_direction_output;
 	gpio->gpio.get = tegra186_gpio_get,
 	gpio->gpio.set = tegra186_gpio_set;
 	gpio->gpio.set_config = tegra186_gpio_set_config;
+	gpio->gpio.add_pin_ranges = tegra186_gpio_add_pin_ranges;
 
 	gpio->gpio.base = -1;