pinctrl: Add Apple pinctrl driver
This driver supports both pin muxing and GPIO support for the
pin control logic found on Apple SoCs.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
diff --git a/drivers/pinctrl/pinctrl-apple.c b/drivers/pinctrl/pinctrl-apple.c
new file mode 100644
index 0000000..6247635
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-apple.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021 Mark Kettenis <kettenis@openbsd.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/pinctrl.h>
+#include <dt-bindings/pinctrl/apple.h>
+#include <asm/io.h>
+#include <asm-generic/gpio.h>
+#include <linux/bitfield.h>
+
+struct apple_pinctrl_priv {
+ void *base;
+ int pin_count;
+};
+
+#define REG_GPIO(x) (4 * (x))
+#define REG_GPIO_DATA BIT(0)
+#define REG_GPIO_MODE GENMASK(3, 1)
+#define REG_GPIO_OUT 1
+#define REG_GPIO_PERIPH GENMASK(6, 5)
+#define REG_GPIO_INPUT_ENABLE BIT(9)
+
+static void apple_pinctrl_config_pin(struct apple_pinctrl_priv *priv,
+ unsigned pin, u32 clr, u32 set)
+{
+ unsigned reg = REG_GPIO(pin);
+ u32 old, new;
+
+ old = readl(priv->base + REG_GPIO(pin));
+ new = (old & ~clr) | set;
+ writel(new, priv->base + reg);
+}
+
+static int apple_gpio_get_value(struct udevice *dev, unsigned offset)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev->parent);
+
+ return !!(readl(priv->base + REG_GPIO(offset)) & REG_GPIO_DATA);
+}
+
+static int apple_gpio_set_value(struct udevice *dev, unsigned offset,
+ int value)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev->parent);
+
+ apple_pinctrl_config_pin(priv, offset, REG_GPIO_DATA,
+ value ? REG_GPIO_DATA : 0);
+ return 0;
+}
+
+static int apple_gpio_get_direction(struct udevice *dev, unsigned offset)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev->parent);
+ u32 reg = readl(priv->base + REG_GPIO(offset));
+
+ if (FIELD_GET(REG_GPIO_MODE, reg) == REG_GPIO_OUT)
+ return GPIOF_OUTPUT;
+ else
+ return GPIOF_INPUT;
+}
+
+static int apple_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev->parent);
+
+ apple_pinctrl_config_pin(priv, offset,
+ REG_GPIO_PERIPH | REG_GPIO_MODE,
+ REG_GPIO_INPUT_ENABLE);
+ return 0;
+}
+
+static int apple_gpio_direction_output(struct udevice *dev, unsigned offset,
+ int value)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev->parent);
+ u32 set = (value ? REG_GPIO_DATA : 0);
+
+ apple_pinctrl_config_pin(priv, offset, REG_GPIO_DATA |
+ REG_GPIO_PERIPH | REG_GPIO_MODE,
+ set | FIELD_PREP(REG_GPIO_MODE, REG_GPIO_OUT));
+ return 0;
+}
+
+static int apple_gpio_probe(struct udevice *dev)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev->parent);
+ struct gpio_dev_priv *uc_priv;
+
+ uc_priv = dev_get_uclass_priv(dev);
+ uc_priv->bank_name = "gpio";
+ uc_priv->gpio_count = priv->pin_count;
+
+ return 0;
+}
+
+static struct dm_gpio_ops apple_gpio_ops = {
+ .get_value = apple_gpio_get_value,
+ .set_value = apple_gpio_set_value,
+ .get_function = apple_gpio_get_direction,
+ .direction_input = apple_gpio_direction_input,
+ .direction_output = apple_gpio_direction_output,
+};
+
+static struct driver apple_gpio_driver = {
+ .name = "apple_gpio",
+ .id = UCLASS_GPIO,
+ .probe = apple_gpio_probe,
+ .ops = &apple_gpio_ops,
+};
+
+static int apple_pinctrl_get_pins_count(struct udevice *dev)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev);
+
+ return priv->pin_count;
+}
+
+static const char *apple_pinctrl_get_pin_name(struct udevice *dev,
+ unsigned selector)
+{
+ static char pin_name[PINNAME_SIZE];
+
+ snprintf(pin_name, PINNAME_SIZE, "pin%d", selector);
+ return pin_name;
+}
+
+static int apple_pinctrl_get_pin_muxing(struct udevice *dev, unsigned selector,
+ char *buf, int size)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev);
+
+ if (readl(priv->base + REG_GPIO(selector)) & REG_GPIO_PERIPH)
+ strncpy(buf, "periph", size);
+ else
+ strncpy(buf, "gpio", size);
+ return 0;
+}
+
+static int apple_pinctrl_pinmux_set(struct udevice *dev, unsigned pin_selector,
+ unsigned func_selector)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev);
+
+ apple_pinctrl_config_pin(priv, pin_selector,
+ REG_GPIO_DATA | REG_GPIO_MODE,
+ FIELD_PREP(REG_GPIO_PERIPH, func_selector) |
+ REG_GPIO_INPUT_ENABLE);
+ return 0;
+}
+
+static int apple_pinctrl_pinmux_property_set(struct udevice *dev,
+ u32 pinmux_group)
+{
+ unsigned pin_selector = APPLE_PIN(pinmux_group);
+ unsigned func_selector = APPLE_FUNC(pinmux_group);
+ int ret;
+
+ ret = apple_pinctrl_pinmux_set(dev, pin_selector, func_selector);
+ return ret ? ret : pin_selector;
+}
+
+static int apple_pinctrl_probe(struct udevice *dev)
+{
+ struct apple_pinctrl_priv *priv = dev_get_priv(dev);
+ struct ofnode_phandle_args args;
+ struct udevice *child;
+
+ priv->base = dev_read_addr_ptr(dev);
+ if (!priv->base)
+ return -EINVAL;
+
+ if (!dev_read_phandle_with_args(dev, "gpio-ranges",
+ NULL, 3, 0, &args))
+ priv->pin_count = args.args[2];
+
+ device_bind(dev, &apple_gpio_driver, "apple_gpio", NULL,
+ dev_ofnode(dev), &child);
+
+ return 0;
+}
+
+static struct pinctrl_ops apple_pinctrl_ops = {
+ .set_state = pinctrl_generic_set_state,
+ .get_pins_count = apple_pinctrl_get_pins_count,
+ .get_pin_name = apple_pinctrl_get_pin_name,
+ .pinmux_set = apple_pinctrl_pinmux_set,
+ .pinmux_property_set = apple_pinctrl_pinmux_property_set,
+ .get_pin_muxing = apple_pinctrl_get_pin_muxing,
+};
+
+static const struct udevice_id apple_pinctrl_ids[] = {
+ { .compatible = "apple,pinctrl" },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(pinctrl_apple) = {
+ .name = "apple_pinctrl",
+ .id = UCLASS_PINCTRL,
+ .of_match = apple_pinctrl_ids,
+ .priv_auto = sizeof(struct apple_pinctrl_priv),
+ .ops = &apple_pinctrl_ops,
+ .probe = apple_pinctrl_probe,
+};