u-boot/drivers/gpio/mcp230xx_gpio.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2021, Collabora Ltd.
* Copyright (C) 2021, General Electric Company
* Author(s): Sebastian Reichel <sebastian.reichel@collabora.com>
*/
#define LOG_CATEGORY UCLASS_GPIO
#include <common.h>
#include <errno.h>
#include <dm.h>
#include <i2c.h>
#include <asm/gpio.h>
#include <dm/device_compat.h>
#include <dt-bindings/gpio/gpio.h>
enum mcp230xx_type {
UNKNOWN = 0,
MCP23008,
MCP23017,
MCP23018,
};
#define MCP230XX_IODIR 0x00
#define MCP230XX_GPPU 0x06
#define MCP230XX_GPIO 0x09
#define MCP230XX_OLAT 0x0a
#define BANKSIZE 8
static int mcp230xx_read(struct udevice *dev, uint reg, uint offset)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
int bank = offset / BANKSIZE;
int mask = 1 << (offset % BANKSIZE);
int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
int ret;
ret = dm_i2c_reg_read(dev, (reg << shift) | bank);
if (ret < 0)
return ret;
return !!(ret & mask);
}
static int mcp230xx_write(struct udevice *dev, uint reg, uint offset, bool val)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
int bank = offset / BANKSIZE;
int mask = 1 << (offset % BANKSIZE);
int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
return dm_i2c_reg_clrset(dev, (reg << shift) | bank, mask, val ? mask : 0);
}
static int mcp230xx_get_value(struct udevice *dev, uint offset)
{
int ret;
ret = mcp230xx_read(dev, MCP230XX_GPIO, offset);
if (ret < 0) {
dev_err(dev, "%s error: %d\n", __func__, ret);
return ret;
}
return ret;
}
static int mcp230xx_set_value(struct udevice *dev, uint offset, int val)
{
int ret;
ret = mcp230xx_write(dev, MCP230XX_GPIO, offset, val);
if (ret < 0) {
dev_err(dev, "%s error: %d\n", __func__, ret);
return ret;
}
return ret;
}
static int mcp230xx_get_flags(struct udevice *dev, unsigned int offset,
ulong *flags)
{
int direction, pullup;
pullup = mcp230xx_read(dev, MCP230XX_GPPU, offset);
if (pullup < 0) {
dev_err(dev, "%s error: %d\n", __func__, pullup);
return pullup;
}
direction = mcp230xx_read(dev, MCP230XX_IODIR, offset);
if (direction < 0) {
dev_err(dev, "%s error: %d\n", __func__, direction);
return direction;
}
*flags = direction ? GPIOD_IS_IN : GPIOD_IS_OUT;
if (pullup)
*flags |= GPIOD_PULL_UP;
return 0;
}
static int mcp230xx_set_flags(struct udevice *dev, uint offset, ulong flags)
{
bool input = !(flags & (GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE));
bool pullup = flags & GPIOD_PULL_UP;
ulong supported_mask;
int ret;
/* Note: active-low is ignored (handled by core) */
supported_mask = GPIOD_ACTIVE_LOW | GPIOD_MASK_DIR | GPIOD_PULL_UP;
if (flags & ~supported_mask) {
dev_err(dev, "%s unsupported flag(s): %lx\n", __func__, flags);
return -EINVAL;
}
ret = mcp230xx_write(dev, MCP230XX_OLAT, offset, !!(flags & GPIOD_IS_OUT_ACTIVE));
if (ret) {
dev_err(dev, "%s failed to setup output latch: %d\n", __func__, ret);
return ret;
}
ret = mcp230xx_write(dev, MCP230XX_GPPU, offset, pullup);
if (ret) {
dev_err(dev, "%s failed to setup pull-up: %d\n", __func__, ret);
return ret;
}
ret = mcp230xx_write(dev, MCP230XX_IODIR, offset, input);
if (ret) {
dev_err(dev, "%s failed to setup direction: %d\n", __func__, ret);
return ret;
}
return 0;
}
static int mcp230xx_direction_input(struct udevice *dev, uint offset)
{
return mcp230xx_set_flags(dev, offset, GPIOD_IS_IN);
}
static int mcp230xx_direction_output(struct udevice *dev, uint offset, int val)
{
int ret = mcp230xx_set_value(dev, offset, val);
if (ret < 0) {
dev_err(dev, "%s error: %d\n", __func__, ret);
return ret;
}
return mcp230xx_set_flags(dev, offset, GPIOD_IS_OUT);
}
static int mcp230xx_get_function(struct udevice *dev, uint offset)
{
int ret;
ret = mcp230xx_read(dev, MCP230XX_IODIR, offset);
if (ret < 0) {
dev_err(dev, "%s error: %d\n", __func__, ret);
return ret;
}
return ret ? GPIOF_INPUT : GPIOF_OUTPUT;
}
static const struct dm_gpio_ops mcp230xx_ops = {
.direction_input = mcp230xx_direction_input,
.direction_output = mcp230xx_direction_output,
.get_value = mcp230xx_get_value,
.set_value = mcp230xx_set_value,
.get_function = mcp230xx_get_function,
.set_flags = mcp230xx_set_flags,
.get_flags = mcp230xx_get_flags,
};
static int mcp230xx_probe(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
char name[32], label[8], *str;
int addr, gpio_count, size;
const u8 *tmp;
switch (dev_get_driver_data(dev)) {
case MCP23008:
gpio_count = 8;
break;
case MCP23017:
case MCP23018:
gpio_count = 16;
break;
default:
return -ENODEV;
}
addr = dev_read_addr(dev);
tmp = dev_read_prop(dev, "label", &size);
if (tmp) {
memcpy(label, tmp, sizeof(label) - 1);
label[sizeof(label) - 1] = '\0';
snprintf(name, sizeof(name), "%s@%x_", label, addr);
} else {
snprintf(name, sizeof(name), "gpio@%x_", addr);
}
str = strdup(name);
if (!str)
return -ENOMEM;
uc_priv->bank_name = str;
uc_priv->gpio_count = gpio_count;
dev_dbg(dev, "%s is ready\n", str);
return 0;
}
static const struct udevice_id mcp230xx_ids[] = {
{ .compatible = "microchip,mcp23008", .data = MCP23008, },
{ .compatible = "microchip,mcp23017", .data = MCP23017, },
{ .compatible = "microchip,mcp23018", .data = MCP23018, },
{ }
};
U_BOOT_DRIVER(mcp230xx) = {
.name = "mcp230xx",
.id = UCLASS_GPIO,
.ops = &mcp230xx_ops,
.probe = mcp230xx_probe,
.of_match = mcp230xx_ids,
};