Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * w1-gpio - GPIO w1 bus master driver
 *
 * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
 */
 
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/w1-gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/of_platform.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/delay.h>
 
#include <linux/w1.h>
 
static u8 w1_gpio_set_pullup(void *data, int delay)
{
<------>struct w1_gpio_platform_data *pdata = data;
 
<------>if (delay) {
<------><------>pdata->pullup_duration = delay;
<------>} else {
<------><------>if (pdata->pullup_duration) {
<------><------><------>/*
<------><------><------> * This will OVERRIDE open drain emulation and force-pull
<------><------><------> * the line high for some time.
<------><------><------> */
<------><------><------>gpiod_set_raw_value(pdata->gpiod, 1);
<------><------><------>msleep(pdata->pullup_duration);
<------><------><------>/*
<------><------><------> * This will simply set the line as input since we are doing
<------><------><------> * open drain emulation in the GPIO library.
<------><------><------> */
<------><------><------>gpiod_set_value(pdata->gpiod, 1);
<------><------>}
<------><------>pdata->pullup_duration = 0;
<------>}
 
<------>return 0;
}
 
static void w1_gpio_write_bit(void *data, u8 bit)
{
<------>struct w1_gpio_platform_data *pdata = data;
 
<------>gpiod_set_value(pdata->gpiod, bit);
}
 
static u8 w1_gpio_read_bit(void *data)
{
<------>struct w1_gpio_platform_data *pdata = data;
 
<------>return gpiod_get_value(pdata->gpiod) ? 1 : 0;
}
 
#if defined(CONFIG_OF)
static const struct of_device_id w1_gpio_dt_ids[] = {
<------>{ .compatible = "w1-gpio" },
<------>{}
};
MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
#endif
 
static int w1_gpio_probe(struct platform_device *pdev)
{
<------>struct w1_bus_master *master;
<------>struct w1_gpio_platform_data *pdata;
<------>struct device *dev = &pdev->dev;
<------>struct device_node *np = dev->of_node;
<------>/* Enforce open drain mode by default */
<------>enum gpiod_flags gflags = GPIOD_OUT_LOW_OPEN_DRAIN;
<------>int err;
 
<------>if (of_have_populated_dt()) {
<------><------>pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
<------><------>if (!pdata)
<------><------><------>return -ENOMEM;
 
<------><------>/*
<------><------> * This parameter means that something else than the gpiolib has
<------><------> * already set the line into open drain mode, so we should just
<------><------> * driver it high/low like we are in full control of the line and
<------><------> * open drain will happen transparently.
<------><------> */
<------><------>if (of_get_property(np, "linux,open-drain", NULL))
<------><------><------>gflags = GPIOD_OUT_LOW;
 
<------><------>pdev->dev.platform_data = pdata;
<------>}
<------>pdata = dev_get_platdata(dev);
 
<------>if (!pdata) {
<------><------>dev_err(dev, "No configuration data\n");
<------><------>return -ENXIO;
<------>}
 
<------>master = devm_kzalloc(dev, sizeof(struct w1_bus_master),
<------><------><------>GFP_KERNEL);
<------>if (!master) {
<------><------>dev_err(dev, "Out of memory\n");
<------><------>return -ENOMEM;
<------>}
 
<------>pdata->gpiod = devm_gpiod_get_index(dev, NULL, 0, gflags);
<------>if (IS_ERR(pdata->gpiod)) {
<------><------>dev_err(dev, "gpio_request (pin) failed\n");
<------><------>return PTR_ERR(pdata->gpiod);
<------>}
 
<------>pdata->pullup_gpiod =
<------><------>devm_gpiod_get_index_optional(dev, NULL, 1, GPIOD_OUT_LOW);
<------>if (IS_ERR(pdata->pullup_gpiod)) {
<------><------>dev_err(dev, "gpio_request_one "
<------><------><------>"(ext_pullup_enable_pin) failed\n");
<------><------>return PTR_ERR(pdata->pullup_gpiod);
<------>}
 
<------>master->data = pdata;
<------>master->read_bit = w1_gpio_read_bit;
<------>gpiod_direction_output(pdata->gpiod, 1);
<------>master->write_bit = w1_gpio_write_bit;
 
<------>/*
<------> * If we are using open drain emulation from the GPIO library,
<------> * we need to use this pullup function that hammers the line
<------> * high using a raw accessor to provide pull-up for the w1
<------> * line.
<------> */
<------>if (gflags == GPIOD_OUT_LOW_OPEN_DRAIN)
<------><------>master->set_pullup = w1_gpio_set_pullup;
 
<------>err = w1_add_master_device(master);
<------>if (err) {
<------><------>dev_err(dev, "w1_add_master device failed\n");
<------><------>return err;
<------>}
 
<------>if (pdata->enable_external_pullup)
<------><------>pdata->enable_external_pullup(1);
 
<------>if (pdata->pullup_gpiod)
<------><------>gpiod_set_value(pdata->pullup_gpiod, 1);
 
<------>platform_set_drvdata(pdev, master);
 
<------>return 0;
}
 
static int w1_gpio_remove(struct platform_device *pdev)
{
<------>struct w1_bus_master *master = platform_get_drvdata(pdev);
<------>struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 
<------>if (pdata->enable_external_pullup)
<------><------>pdata->enable_external_pullup(0);
 
<------>if (pdata->pullup_gpiod)
<------><------>gpiod_set_value(pdata->pullup_gpiod, 0);
 
<------>w1_remove_master_device(master);
 
<------>return 0;
}
 
static int __maybe_unused w1_gpio_suspend(struct device *dev)
{
<------>struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
 
<------>if (pdata->enable_external_pullup)
<------><------>pdata->enable_external_pullup(0);
 
<------>return 0;
}
 
static int __maybe_unused w1_gpio_resume(struct device *dev)
{
<------>struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
 
<------>if (pdata->enable_external_pullup)
<------><------>pdata->enable_external_pullup(1);
 
<------>return 0;
}
 
static SIMPLE_DEV_PM_OPS(w1_gpio_pm_ops, w1_gpio_suspend, w1_gpio_resume);
 
static struct platform_driver w1_gpio_driver = {
<------>.driver = {
<------><------>.name	= "w1-gpio",
<------><------>.pm	= &w1_gpio_pm_ops,
<------><------>.of_match_table = of_match_ptr(w1_gpio_dt_ids),
<------>},
<------>.probe = w1_gpio_probe,
<------>.remove = w1_gpio_remove,
};
 
module_platform_driver(w1_gpio_driver);
 
MODULE_DESCRIPTION("GPIO w1 bus master driver");
MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
MODULE_LICENSE("GPL");