Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756352AbXLUHeQ (ORCPT ); Fri, 21 Dec 2007 02:34:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751875AbXLUHeF (ORCPT ); Fri, 21 Dec 2007 02:34:05 -0500 Received: from smtp6.pp.htv.fi ([213.243.153.40]:57906 "EHLO smtp6.pp.htv.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751016AbXLUHeE (ORCPT ); Fri, 21 Dec 2007 02:34:04 -0500 From: Ville Syrjala To: Evgeniy Polyakov Cc: linux-kernel@vger.kernel.org, Ville Syrjala Subject: [PATCH] w1-gpio: Add GPIO w1 bus master driver Date: Fri, 21 Dec 2007 09:34:01 +0200 Message-Id: <1198222441690-git-send-email-syrjala@sci.fi> X-Mailer: git-send-email 1.5.2.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6459 Lines: 236 Add a GPIO 1-wire bus master driver. The driver used the GPIO API to control the wire and the GPIO pin can be specified using platform data similar to i2c-gpio. The driver was tested with AT91SAM9260 + DS2401. Signed-off-by: Ville Syrjala --- Documentation/w1/masters/00-INDEX | 2 + Documentation/w1/masters/w1-gpio | 33 ++++++++++++ drivers/w1/masters/Kconfig | 10 ++++ drivers/w1/masters/Makefile | 1 + drivers/w1/masters/w1-gpio.c | 100 +++++++++++++++++++++++++++++++++++++ include/linux/w1-gpio.h | 21 ++++++++ 6 files changed, 167 insertions(+), 0 deletions(-) create mode 100644 Documentation/w1/masters/w1-gpio create mode 100644 drivers/w1/masters/w1-gpio.c create mode 100644 include/linux/w1-gpio.h 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..c927139 --- /dev/null +++ b/Documentation/w1/masters/w1-gpio @@ -0,0 +1,33 @@ +Kernel driver w1-gpio +===================== + +Author: Ville Syrjala + + +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. The GPIO pin +must be configured as open-drain. + + +Example (mach-at91) +------------------- + +#include + +static struct w1_gpio_platform_data foo_w1_gpio_pdata = { + .pin = AT91_PIN_PB20, +}; + +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..c5327df --- /dev/null +++ b/drivers/w1/masters/w1-gpio.c @@ -0,0 +1,100 @@ +/* + * w1-gpio - GPIO w1 bus master driver + * + * Copyright (C) 2007 Ville Syrjala + * + * 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 +#include +#include +#include + +#include "../w1.h" +#include "../w1_int.h" + +#include + +static void w1_gpio_write_bit(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; + int err; + + pdata = pdev->dev.platform_data; + if (!pdata) + return -ENXIO; + + master = kzalloc(sizeof *master, GFP_KERNEL); + if (!master) + return -ENOMEM; + + gpio_direction_output(pdata->pin, 1); + + master->data = pdata; + master->read_bit = &w1_gpio_read_bit; + master->write_bit = &w1_gpio_write_bit; + + err = w1_add_master_device(master); + if (err) { + kfree(master); + return err; + } + + platform_set_drvdata(pdev, master); + + return 0; +} + +static int __exit w1_gpio_remove(struct platform_device *pdev) +{ + struct w1_bus_master *master = platform_get_drvdata(pdev); + + w1_remove_master_device(master); + kfree(master); + + return 0; +} + +static struct platform_driver w1_gpio_driver = { + .driver = { + .name = "w1-gpio", + .owner = THIS_MODULE, + }, + .probe = w1_gpio_probe, + .remove = __exit_p(w1_gpio_remove), +}; + +static int __init w1_gpio_init(void) +{ + return platform_driver_register(&w1_gpio_driver); +} + +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 "); +MODULE_LICENSE("GPL"); diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h new file mode 100644 index 0000000..3b80bb2 --- /dev/null +++ b/include/linux/w1-gpio.h @@ -0,0 +1,21 @@ +/* + * w1-gpio interface to platform code + * + * Copyright (C) 2007 Ville Syrjala + * + * 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 + */ +struct w1_gpio_platform_data { + unsigned int pin; +}; + +#endif /* _LINUX_W1_GPIO_H */ -- 1.5.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/