u-boot/drivers/gpio/pca953x_gpio.c
Mario Six 1e5f89881a gpio: pca953x_gpio: Support label setting from DT
The PCA953x driver uses "gpio@%x_" as the GPIO bank name, where "%x" is
instantiated with the I2C address of the chip. While this works, it
becomes very confusing if a board has multiple PCAs with the same
address on different I2C busses, and it also becomes an issue when a
GPIO's value is to be set via the 'gpio' command, because this command
only ever sets the value of the first device it encounters, leaving the
other devices inaccessible to the command.

As to not break boards that rely on this naming scheme, we introduce a
new device tree string property "label" for the driver. If it exists, it
is used to build a bank name of the form "%s@%x_" (where %x is still
instantiated with the I2C address). If it does not exist, the legacy
labeling scheme is used.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
2018-03-05 10:06:05 -05:00

354 lines
8.9 KiB
C

/*
* Take linux kernel driver drivers/gpio/gpio-pca953x.c for reference.
*
* Copyright (C) 2016 Peng Fan <van.freenix@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*
*/
/*
* Note:
* The driver's compatible table is borrowed from Linux Kernel,
* but now max supported gpio pins is 24 and only PCA953X_TYPE
* is supported. PCA957X_TYPE is not supported now.
* Also the Polarity Inversion feature is not supported now.
*
* TODO:
* 1. Support PCA957X_TYPE
* 2. Support 24 gpio pins
* 3. Support Polarity Inversion
*/
#include <common.h>
#include <errno.h>
#include <dm.h>
#include <fdtdec.h>
#include <i2c.h>
#include <malloc.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <dt-bindings/gpio/gpio.h>
#define PCA953X_INPUT 0
#define PCA953X_OUTPUT 1
#define PCA953X_INVERT 2
#define PCA953X_DIRECTION 3
#define PCA_GPIO_MASK 0x00FF
#define PCA_INT 0x0100
#define PCA953X_TYPE 0x1000
#define PCA957X_TYPE 0x2000
#define PCA_TYPE_MASK 0xF000
#define PCA_CHIP_TYPE(x) ((x) & PCA_TYPE_MASK)
enum {
PCA953X_DIRECTION_IN,
PCA953X_DIRECTION_OUT,
};
#define MAX_BANK 5
#define BANK_SZ 8
/*
* struct pca953x_info - Data for pca953x
*
* @dev: udevice structure for the device
* @addr: i2c slave address
* @invert: Polarity inversion or not
* @gpio_count: the number of gpio pins that the device supports
* @chip_type: indicate the chip type,PCA953X or PCA957X
* @bank_count: the number of banks that the device supports
* @reg_output: array to hold the value of output registers
* @reg_direction: array to hold the value of direction registers
*/
struct pca953x_info {
struct udevice *dev;
int addr;
int invert;
int gpio_count;
int chip_type;
int bank_count;
u8 reg_output[MAX_BANK];
u8 reg_direction[MAX_BANK];
};
static int pca953x_write_single(struct udevice *dev, int reg, u8 val,
int offset)
{
struct pca953x_info *info = dev_get_platdata(dev);
int bank_shift = fls((info->gpio_count - 1) / BANK_SZ);
int off = offset / BANK_SZ;
int ret = 0;
ret = dm_i2c_write(dev, (reg << bank_shift) + off, &val, 1);
if (ret) {
dev_err(dev, "%s error\n", __func__);
return ret;
}
return 0;
}
static int pca953x_read_single(struct udevice *dev, int reg, u8 *val,
int offset)
{
struct pca953x_info *info = dev_get_platdata(dev);
int bank_shift = fls((info->gpio_count - 1) / BANK_SZ);
int off = offset / BANK_SZ;
int ret;
u8 byte;
ret = dm_i2c_read(dev, (reg << bank_shift) + off, &byte, 1);
if (ret) {
dev_err(dev, "%s error\n", __func__);
return ret;
}
*val = byte;
return 0;
}
static int pca953x_read_regs(struct udevice *dev, int reg, u8 *val)
{
struct pca953x_info *info = dev_get_platdata(dev);
int ret = 0;
if (info->gpio_count <= 8) {
ret = dm_i2c_read(dev, reg, val, 1);
} else if (info->gpio_count <= 16) {
ret = dm_i2c_read(dev, reg << 1, val, info->bank_count);
} else if (info->gpio_count == 40) {
/* Auto increment */
ret = dm_i2c_read(dev, (reg << 3) | 0x80, val,
info->bank_count);
} else {
dev_err(dev, "Unsupported now\n");
return -EINVAL;
}
return ret;
}
static int pca953x_is_output(struct udevice *dev, int offset)
{
struct pca953x_info *info = dev_get_platdata(dev);
int bank = offset / BANK_SZ;
int off = offset % BANK_SZ;
/*0: output; 1: input */
return !(info->reg_direction[bank] & (1 << off));
}
static int pca953x_get_value(struct udevice *dev, uint offset)
{
int ret;
u8 val = 0;
int off = offset % BANK_SZ;
ret = pca953x_read_single(dev, PCA953X_INPUT, &val, offset);
if (ret)
return ret;
return (val >> off) & 0x1;
}
static int pca953x_set_value(struct udevice *dev, uint offset, int value)
{
struct pca953x_info *info = dev_get_platdata(dev);
int bank = offset / BANK_SZ;
int off = offset % BANK_SZ;
u8 val;
int ret;
if (value)
val = info->reg_output[bank] | (1 << off);
else
val = info->reg_output[bank] & ~(1 << off);
ret = pca953x_write_single(dev, PCA953X_OUTPUT, val, offset);
if (ret)
return ret;
info->reg_output[bank] = val;
return 0;
}
static int pca953x_set_direction(struct udevice *dev, uint offset, int dir)
{
struct pca953x_info *info = dev_get_platdata(dev);
int bank = offset / BANK_SZ;
int off = offset % BANK_SZ;
u8 val;
int ret;
if (dir == PCA953X_DIRECTION_IN)
val = info->reg_direction[bank] | (1 << off);
else
val = info->reg_direction[bank] & ~(1 << off);
ret = pca953x_write_single(dev, PCA953X_DIRECTION, val, offset);
if (ret)
return ret;
info->reg_direction[bank] = val;
return 0;
}
static int pca953x_direction_input(struct udevice *dev, uint offset)
{
return pca953x_set_direction(dev, offset, PCA953X_DIRECTION_IN);
}
static int pca953x_direction_output(struct udevice *dev, uint offset, int value)
{
/* Configure output value. */
pca953x_set_value(dev, offset, value);
/* Configure direction as output. */
pca953x_set_direction(dev, offset, PCA953X_DIRECTION_OUT);
return 0;
}
static int pca953x_get_function(struct udevice *dev, uint offset)
{
if (pca953x_is_output(dev, offset))
return GPIOF_OUTPUT;
else
return GPIOF_INPUT;
}
static int pca953x_xlate(struct udevice *dev, struct gpio_desc *desc,
struct ofnode_phandle_args *args)
{
desc->offset = args->args[0];
desc->flags = args->args[1] & (GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0);
return 0;
}
static const struct dm_gpio_ops pca953x_ops = {
.direction_input = pca953x_direction_input,
.direction_output = pca953x_direction_output,
.get_value = pca953x_get_value,
.set_value = pca953x_set_value,
.get_function = pca953x_get_function,
.xlate = pca953x_xlate,
};
static int pca953x_probe(struct udevice *dev)
{
struct pca953x_info *info = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
char name[32], label[8], *str;
int addr;
ulong driver_data;
int ret;
int size;
const u8 *tmp;
addr = dev_read_addr(dev);
if (addr == 0)
return -ENODEV;
info->addr = addr;
driver_data = dev_get_driver_data(dev);
info->gpio_count = driver_data & PCA_GPIO_MASK;
if (info->gpio_count > MAX_BANK * BANK_SZ) {
dev_err(dev, "Max support %d pins now\n", MAX_BANK * BANK_SZ);
return -EINVAL;
}
info->chip_type = PCA_CHIP_TYPE(driver_data);
if (info->chip_type != PCA953X_TYPE) {
dev_err(dev, "Only support PCA953X chip type now.\n");
return -EINVAL;
}
info->bank_count = DIV_ROUND_UP(info->gpio_count, BANK_SZ);
ret = pca953x_read_regs(dev, PCA953X_OUTPUT, info->reg_output);
if (ret) {
dev_err(dev, "Error reading output register\n");
return ret;
}
ret = pca953x_read_regs(dev, PCA953X_DIRECTION, info->reg_direction);
if (ret) {
dev_err(dev, "Error reading direction register\n");
return ret;
}
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, info->addr);
} else {
snprintf(name, sizeof(name), "gpio@%x_", info->addr);
}
str = strdup(name);
if (!str)
return -ENOMEM;
uc_priv->bank_name = str;
uc_priv->gpio_count = info->gpio_count;
dev_dbg(dev, "%s is ready\n", str);
return 0;
}
#define OF_953X(__nrgpio, __int) (ulong)(__nrgpio | PCA953X_TYPE | __int)
#define OF_957X(__nrgpio, __int) (ulong)(__nrgpio | PCA957X_TYPE | __int)
static const struct udevice_id pca953x_ids[] = {
{ .compatible = "nxp,pca9505", .data = OF_953X(40, PCA_INT), },
{ .compatible = "nxp,pca9534", .data = OF_953X(8, PCA_INT), },
{ .compatible = "nxp,pca9535", .data = OF_953X(16, PCA_INT), },
{ .compatible = "nxp,pca9536", .data = OF_953X(4, 0), },
{ .compatible = "nxp,pca9537", .data = OF_953X(4, PCA_INT), },
{ .compatible = "nxp,pca9538", .data = OF_953X(8, PCA_INT), },
{ .compatible = "nxp,pca9539", .data = OF_953X(16, PCA_INT), },
{ .compatible = "nxp,pca9554", .data = OF_953X(8, PCA_INT), },
{ .compatible = "nxp,pca9555", .data = OF_953X(16, PCA_INT), },
{ .compatible = "nxp,pca9556", .data = OF_953X(8, 0), },
{ .compatible = "nxp,pca9557", .data = OF_953X(8, 0), },
{ .compatible = "nxp,pca9574", .data = OF_957X(8, PCA_INT), },
{ .compatible = "nxp,pca9575", .data = OF_957X(16, PCA_INT), },
{ .compatible = "nxp,pca9698", .data = OF_953X(40, 0), },
{ .compatible = "maxim,max7310", .data = OF_953X(8, 0), },
{ .compatible = "maxim,max7312", .data = OF_953X(16, PCA_INT), },
{ .compatible = "maxim,max7313", .data = OF_953X(16, PCA_INT), },
{ .compatible = "maxim,max7315", .data = OF_953X(8, PCA_INT), },
{ .compatible = "ti,pca6107", .data = OF_953X(8, PCA_INT), },
{ .compatible = "ti,tca6408", .data = OF_953X(8, PCA_INT), },
{ .compatible = "ti,tca6416", .data = OF_953X(16, PCA_INT), },
{ .compatible = "ti,tca6424", .data = OF_953X(24, PCA_INT), },
{ .compatible = "onsemi,pca9654", .data = OF_953X(8, PCA_INT), },
{ .compatible = "exar,xra1202", .data = OF_953X(8, 0), },
{ }
};
U_BOOT_DRIVER(pca953x) = {
.name = "pca953x",
.id = UCLASS_GPIO,
.ops = &pca953x_ops,
.probe = pca953x_probe,
.platdata_auto_alloc_size = sizeof(struct pca953x_info),
.of_match = pca953x_ids,
};