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>

3 files changed, 219 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 42f25e24fb..03946245c7 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -145,6 +145,17 @@ config SPL_PINCONF_RECURSIVE
 
 if PINCTRL || SPL_PINCTRL
 
+config PINCTRL_APPLE
+	bool "Apple pinctrl driver"
+	depends on DM && PINCTRL_GENERIC && ARCH_APPLE
+	default y
+	help
+	  Support pin multiplexing on Apple SoCs.
+
+	  The driver is controlled by a device tree node which contains
+	  both the GPIO definitions and pin control functions for each
+	  available multiplex function.
+
 config PINCTRL_AR933X
 	bool "QCA/Athores ar933x pin control driver"
 	depends on DM && SOC_AR933X
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 05b71f2f13..fd736a7f64 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -3,6 +3,7 @@
 obj-y					+= pinctrl-uclass.o
 obj-$(CONFIG_$(SPL_)PINCTRL_GENERIC)	+= pinctrl-generic.o
 
+obj-$(CONFIG_PINCTRL_APPLE)		+= pinctrl-apple.o
 obj-$(CONFIG_PINCTRL_AT91)		+= pinctrl-at91.o
 obj-$(CONFIG_PINCTRL_AT91PIO4)		+= pinctrl-at91-pio4.o
 obj-y					+= nxp/
diff --git a/drivers/pinctrl/pinctrl-apple.c b/drivers/pinctrl/pinctrl-apple.c
new file mode 100644
index 0000000000..62476358c3
--- /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,
+};