u-boot/drivers/gpio/max7320_gpio.c
Hannes Schmelzer bba76a17bd drivers/gpio: add support for MAX7320 i2c i/o expander
This commit adds support for the MAX7320 (and clones) gpio expander.

Signed-off-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
2021-10-19 11:25:24 -04:00

113 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* max7320 I2C GPIO EXPANDER DRIVER
*
* Copyright (C) 2021 Hannes Schmelzer <oe5hpm@oevsv.at>
* B&R Industrial Automation GmbH - http://www.br-automation.com
*
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <asm-generic/gpio.h>
#include <linux/bitops.h>
struct max7320_chip {
u32 outreg;
};
static int max7320_direction_output(struct udevice *dev,
unsigned int offset, int value)
{
struct max7320_chip *plat = dev_get_plat(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct dm_i2c_chip *chip = dev_get_parent_plat(dev);
int ret;
if (value)
plat->outreg |= BIT(offset);
else
plat->outreg &= ~BIT(offset);
ret = dm_i2c_write(dev,
plat->outreg & 0xff,
(uint8_t *)&plat->outreg + 1,
uc_priv->gpio_count > 8 ? 1 : 0);
if (ret)
printf("%s i2c write failed to addr %x\n", __func__,
chip->chip_addr);
return ret;
}
static int max7320_get_value(struct udevice *dev, unsigned int offset)
{
struct max7320_chip *plat = dev_get_plat(dev);
return (plat->outreg >> offset) & 0x1;
}
static int max7320_set_value(struct udevice *dev, unsigned int offset,
int value)
{
return max7320_direction_output(dev, offset, value);
}
static int max7320_get_function(struct udevice *dev, unsigned int offset)
{
return GPIOF_OUTPUT;
}
static int max7320_ofdata_plat(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", 8);
if (uc_priv->gpio_count > 16) {
printf("%s: max7320 doesn't support more than 16 gpios!",
__func__);
return -EINVAL;
}
uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
"gpio-bank-name", NULL);
if (!uc_priv->bank_name)
uc_priv->bank_name = fdt_get_name(gd->fdt_blob,
dev_of_offset(dev), NULL);
return 0;
}
static int max7320_gpio_probe(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
debug("%s GPIO controller with %d gpios probed\n",
uc_priv->bank_name, uc_priv->gpio_count);
return 0;
}
static const struct dm_gpio_ops max7320_gpio_ops = {
.direction_output = max7320_direction_output,
.set_value = max7320_set_value,
.get_value = max7320_get_value,
.get_function = max7320_get_function,
};
static const struct udevice_id max7320_gpio_ids[] = {
{ .compatible = "maxim,max7320" },
{ }
};
U_BOOT_DRIVER(gpio_max7320) = {
.name = "gpio_max7320",
.id = UCLASS_GPIO,
.ops = &max7320_gpio_ops,
.of_match = max7320_gpio_ids,
.of_to_plat = max7320_ofdata_plat,
.probe = max7320_gpio_probe,
.plat_auto = sizeof(struct max7320_chip),
};