diff options
| -rw-r--r-- | Documentation/w1/masters/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/w1/masters/w1-gpio | 33 | ||||
| -rw-r--r-- | drivers/w1/masters/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/w1/masters/Makefile | 1 | ||||
| -rw-r--r-- | drivers/w1/masters/w1-gpio.c | 124 | ||||
| -rw-r--r-- | include/linux/w1-gpio.h | 23 |
6 files changed, 193 insertions, 0 deletions
diff --git a/Documentation/w1/masters/00-INDEX b/Documentation/w1/masters/00-INDEX index 752613c..7b0ceaa 100644 --- a/Documentation/w1/masters/00-INDEX +++ b/Documentation/w1/masters/00-INDEX @@ -4,3 +4,5 @@ ds2482 - The Maxim/Dallas Semiconductor DS2482 provides 1-wire busses. ds2490 - The Maxim/Dallas Semiconductor DS2490 builds USB <-> W1 bridges. +w1-gpio + - GPIO 1-wire bus master driver. diff --git a/Documentation/w1/masters/w1-gpio b/Documentation/w1/masters/w1-gpio new file mode 100644 index 0000000..af5d3b4 --- /dev/null +++ b/Documentation/w1/masters/w1-gpio @@ -0,0 +1,33 @@ +Kernel driver w1-gpio +===================== + +Author: Ville Syrjala <syrjala@sci.fi> + + +Description +----------- + +GPIO 1-wire bus master driver. The driver uses the GPIO API to control the +wire and the GPIO pin can be specified using platform data. + + +Example (mach-at91) +------------------- + +#include <linux/w1-gpio.h> + +static struct w1_gpio_platform_data foo_w1_gpio_pdata = { + .pin = AT91_PIN_PB20, + .is_open_drain = 1, +}; + +static struct platform_device foo_w1_device = { + .name = "w1-gpio", + .id = -1, + .dev.platform_data = &foo_w1_gpio_pdata, +}; + +... + at91_set_GPIO_periph(foo_w1_gpio_pdata.pin, 1); + at91_set_multi_drive(foo_w1_gpio_pdata.pin, 1); + platform_device_register(&foo_w1_device); diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig index 8236d44..c449309 100644 --- a/drivers/w1/masters/Kconfig +++ b/drivers/w1/masters/Kconfig @@ -42,5 +42,15 @@ config W1_MASTER_DS1WM in HP iPAQ devices like h5xxx, h2200, and ASIC3-based like hx4700. +config W1_MASTER_GPIO + tristate "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. + + This support is also available as a module. If so, the module + will be called w1-gpio.ko. + endmenu diff --git a/drivers/w1/masters/Makefile b/drivers/w1/masters/Makefile index 11551b3..1420b5b 100644 --- a/drivers/w1/masters/Makefile +++ b/drivers/w1/masters/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_W1_MASTER_MATROX) += matrox_w1.o obj-$(CONFIG_W1_MASTER_DS2490) += ds2490.o obj-$(CONFIG_W1_MASTER_DS2482) += ds2482.o obj-$(CONFIG_W1_MASTER_DS1WM) += ds1wm.o +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 0000000..9e1138a --- /dev/null +++ b/drivers/w1/masters/w1-gpio.c @@ -0,0 +1,124 @@ +/* + * w1-gpio - GPIO w1 bus master driver + * + * 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. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/w1-gpio.h> + +#include "../w1.h" +#include "../w1_int.h" + +#include <asm/gpio.h> + +static void w1_gpio_write_bit_dir(void *data, u8 bit) +{ + struct w1_gpio_platform_data *pdata = data; + + if (bit) + gpio_direction_input(pdata->pin); + else + gpio_direction_output(pdata->pin, 0); +} + +static void w1_gpio_write_bit_val(void *data, u8 bit) +{ + struct w1_gpio_platform_data *pdata = data; + + gpio_set_value(pdata->pin, bit); +} + +static u8 w1_gpio_read_bit(void *data) +{ + struct w1_gpio_platform_data *pdata = data; + + return gpio_get_value(pdata->pin); +} + +static int __init w1_gpio_probe(struct platform_device *pdev) +{ + struct w1_bus_master *master; + struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + int err; + + if (!pdata) + return -ENXIO; + + master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL); + if (!master) + return -ENOMEM; + + err = gpio_request(pdata->pin, "w1"); + if (err) + goto free_master; + + 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; + } + + err = w1_add_master_device(master); + if (err) + goto free_gpio; + + platform_set_drvdata(pdev, master); + + return 0; + + free_gpio: + gpio_free(pdata->pin); + free_master: + kfree(master); + + return err; +} + +static int __exit w1_gpio_remove(struct platform_device *pdev) +{ + struct w1_bus_master *master = platform_get_drvdata(pdev); + struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + + w1_remove_master_device(master); + gpio_free(pdata->pin); + kfree(master); + + return 0; +} + +static struct platform_driver w1_gpio_driver = { + .driver = { + .name = "w1-gpio", + .owner = THIS_MODULE, + }, + .remove = __exit_p(w1_gpio_remove), +}; + +static int __init w1_gpio_init(void) +{ + return platform_driver_probe(&w1_gpio_driver, w1_gpio_probe); +} + +static void __exit w1_gpio_exit(void) +{ + platform_driver_unregister(&w1_gpio_driver); +} + +module_init(w1_gpio_init); +module_exit(w1_gpio_exit); + +MODULE_DESCRIPTION("GPIO w1 bus master driver"); +MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h new file mode 100644 index 0000000..9797fec --- /dev/null +++ b/include/linux/w1-gpio.h @@ -0,0 +1,23 @@ +/* + * 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; +}; + +#endif /* _LINUX_W1_GPIO_H */ |