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/*
* w1-gpio - GPIO w1 bus master driver
*
* Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
* Copyright (c) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*/
#include <common.h>
#include <init.h>
#include <malloc.h>
#include <xfuncs.h>
#include <driver.h>
#include <linux/w1-gpio.h>
#include <gpio.h>
#include <of_gpio.h>
#include "../w1.h"
static void w1_gpio_write_bit_dir(struct w1_bus *bus, u8 bit)
{
struct w1_gpio_platform_data *pdata = bus->data;
if (bit)
gpio_direction_input(pdata->pin);
else
gpio_direction_output(pdata->pin, 0);
}
static void w1_gpio_write_bit_val(struct w1_bus *bus, u8 bit)
{
struct w1_gpio_platform_data *pdata = bus->data;
gpio_set_value(pdata->pin, bit);
}
static u8 w1_gpio_read_bit(struct w1_bus *bus)
{
struct w1_gpio_platform_data *pdata = bus->data;
return gpio_get_value(pdata->pin) ? 1 : 0;
}
static int w1_gpio_probe_dt(struct device_d *dev)
{
struct w1_gpio_platform_data *pdata;
struct device_node *np = dev->device_node;
int gpio;
if (dev->platform_data)
return 0;
pdata = xzalloc(sizeof(*pdata));
if (of_get_property(np, "linux,open-drain", NULL))
pdata->is_open_drain = 1;
gpio = of_get_gpio(np, 0);
if (!gpio_is_valid(gpio)) {
if (gpio != -EPROBE_DEFER)
dev_err(dev,
"Failed to parse gpio property for data pin (%d)\n",
gpio);
goto free_pdata;
}
pdata->pin = gpio;
gpio = of_get_gpio(np, 1);
if (gpio == -EPROBE_DEFER)
goto free_pdata;
/* ignore other errors as the pullup gpio is optional */
pdata->ext_pullup_enable_pin = gpio;
dev->platform_data = pdata;
return 0;
free_pdata:
free(pdata);
return gpio;
}
static int __init w1_gpio_probe(struct device_d *dev)
{
struct w1_bus *master;
struct w1_gpio_platform_data *pdata;
int err;
if (IS_ENABLED(CONFIG_OFDEVICE)) {
err = w1_gpio_probe_dt(dev);
if (err < 0)
return err;
}
pdata = dev->platform_data;
if (!pdata)
return -ENXIO;
master = xzalloc(sizeof(struct w1_bus));
err = gpio_request(pdata->pin, "w1");
if (err)
goto free_master;
if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
err = gpio_request(pdata->pin, "w1 pullup");
if (err < 0)
goto free_gpio;
gpio_direction_output(pdata->pin, 0);
}
master->data = pdata;
master->read_bit = w1_gpio_read_bit;
if (pdata->is_open_drain) {
gpio_direction_output(pdata->pin, 1);
master->write_bit = w1_gpio_write_bit_val;
} else {
gpio_direction_input(pdata->pin);
master->write_bit = w1_gpio_write_bit_dir;
}
master->parent = dev;
err = w1_bus_register(master);
if (err)
goto free_gpio_ext_pu;
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_set_value(pdata->ext_pullup_enable_pin, 1);
return 0;
free_gpio_ext_pu:
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_free(pdata->ext_pullup_enable_pin);
free_gpio:
gpio_free(pdata->pin);
free_master:
kfree(master);
return err;
}
static __maybe_unused const struct of_device_id w1_gpio_dt_ids[] = {
{ .compatible = "w1-gpio" },
{}
};
static struct driver_d w1_gpio_driver = {
.name = "w1-gpio",
.probe = w1_gpio_probe,
.of_compatible = DRV_OF_COMPAT(w1_gpio_dt_ids),
};
device_platform_driver(w1_gpio_driver);
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