diff options
| -rw-r--r-- | drivers/w1/masters/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/w1/masters/Makefile | 1 | ||||
| -rw-r--r-- | drivers/w1/masters/w1-gpio.c | 116 | ||||
| -rw-r--r-- | include/linux/w1-gpio.h | 25 |
4 files changed, 149 insertions, 0 deletions
diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig index 86aa8dff70..e429c14fb9 100644 --- a/drivers/w1/masters/Kconfig +++ b/drivers/w1/masters/Kconfig @@ -4,4 +4,11 @@ menu "1-wire Bus Masters" +config W1_MASTER_GPIO + bool "GPIO 1-wire busmaster" + depends on GENERIC_GPIO + help + Say Y here if you want to communicate with your 1-wire devices using + GPIO pins. This driver uses the GPIO API to control the wire. + endmenu diff --git a/drivers/w1/masters/Makefile b/drivers/w1/masters/Makefile index ed1b9d9c4a..84b35bb0eb 100644 --- a/drivers/w1/masters/Makefile +++ b/drivers/w1/masters/Makefile @@ -2,3 +2,4 @@ # Makefile for 1-wire bus master drivers. # +obj-$(CONFIG_W1_MASTER_GPIO) += w1-gpio.o diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c new file mode 100644 index 0000000000..0a3794d144 --- /dev/null +++ b/drivers/w1/masters/w1-gpio.c @@ -0,0 +1,116 @@ +/* + * 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 "../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 __init w1_gpio_probe(struct device_d *dev) +{ + struct w1_bus *master; + struct w1_gpio_platform_data *pdata; + int 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 struct driver_d w1_gpio_driver = { + .name = "w1-gpio", + .probe = w1_gpio_probe, +}; + +static int __init w1_gpio_init(void) +{ + return platform_driver_register(&w1_gpio_driver); +} +device_initcall(w1_gpio_init); diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h new file mode 100644 index 0000000000..065e3ae79a --- /dev/null +++ b/include/linux/w1-gpio.h @@ -0,0 +1,25 @@ +/* + * w1-gpio interface to platform code + * + * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi> + * + * 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. + */ +#ifndef _LINUX_W1_GPIO_H +#define _LINUX_W1_GPIO_H + +/** + * struct w1_gpio_platform_data - Platform-dependent data for w1-gpio + * @pin: GPIO pin to use + * @is_open_drain: GPIO pin is configured as open drain + */ +struct w1_gpio_platform_data { + unsigned int pin; + unsigned int is_open_drain:1; + void (*enable_external_pullup)(int enable); + unsigned int ext_pullup_enable_pin; +}; + +#endif /* _LINUX_W1_GPIO_H */ |