u-boot/drivers/pinctrl/pinctrl-apple.c
Mark Kettenis b814e0007e 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>
2021-11-17 17:04:58 -05:00

207 lines
5.2 KiB
C

// 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,
};