| Ville Syrjala | ad8dc96 | 2008-02-06 01:39:01 -0800 | [diff] [blame] | 1 | /* |
| 2 | * w1-gpio - GPIO w1 bus master driver |
| 3 | * |
| 4 | * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 |
| 8 | * as published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/platform_device.h> |
| 14 | #include <linux/w1-gpio.h> |
| 15 | |
| 16 | #include "../w1.h" |
| 17 | #include "../w1_int.h" |
| 18 | |
| 19 | #include <asm/gpio.h> |
| 20 | |
| 21 | static void w1_gpio_write_bit_dir(void *data, u8 bit) |
| 22 | { |
| 23 | struct w1_gpio_platform_data *pdata = data; |
| 24 | |
| 25 | if (bit) |
| 26 | gpio_direction_input(pdata->pin); |
| 27 | else |
| 28 | gpio_direction_output(pdata->pin, 0); |
| 29 | } |
| 30 | |
| 31 | static void w1_gpio_write_bit_val(void *data, u8 bit) |
| 32 | { |
| 33 | struct w1_gpio_platform_data *pdata = data; |
| 34 | |
| 35 | gpio_set_value(pdata->pin, bit); |
| 36 | } |
| 37 | |
| 38 | static u8 w1_gpio_read_bit(void *data) |
| 39 | { |
| 40 | struct w1_gpio_platform_data *pdata = data; |
| 41 | |
| 42 | return gpio_get_value(pdata->pin); |
| 43 | } |
| 44 | |
| 45 | static int __init w1_gpio_probe(struct platform_device *pdev) |
| 46 | { |
| 47 | struct w1_bus_master *master; |
| 48 | struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; |
| 49 | int err; |
| 50 | |
| 51 | if (!pdata) |
| 52 | return -ENXIO; |
| 53 | |
| 54 | master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL); |
| 55 | if (!master) |
| 56 | return -ENOMEM; |
| 57 | |
| 58 | err = gpio_request(pdata->pin, "w1"); |
| 59 | if (err) |
| 60 | goto free_master; |
| 61 | |
| 62 | master->data = pdata; |
| 63 | master->read_bit = w1_gpio_read_bit; |
| 64 | |
| 65 | if (pdata->is_open_drain) { |
| 66 | gpio_direction_output(pdata->pin, 1); |
| 67 | master->write_bit = w1_gpio_write_bit_val; |
| 68 | } else { |
| 69 | gpio_direction_input(pdata->pin); |
| 70 | master->write_bit = w1_gpio_write_bit_dir; |
| 71 | } |
| 72 | |
| 73 | err = w1_add_master_device(master); |
| 74 | if (err) |
| 75 | goto free_gpio; |
| 76 | |
| 77 | platform_set_drvdata(pdev, master); |
| 78 | |
| 79 | return 0; |
| 80 | |
| 81 | free_gpio: |
| 82 | gpio_free(pdata->pin); |
| 83 | free_master: |
| 84 | kfree(master); |
| 85 | |
| 86 | return err; |
| 87 | } |
| 88 | |
| 89 | static int __exit w1_gpio_remove(struct platform_device *pdev) |
| 90 | { |
| 91 | struct w1_bus_master *master = platform_get_drvdata(pdev); |
| 92 | struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; |
| 93 | |
| 94 | w1_remove_master_device(master); |
| 95 | gpio_free(pdata->pin); |
| 96 | kfree(master); |
| 97 | |
| 98 | return 0; |
| 99 | } |
| 100 | |
| 101 | static struct platform_driver w1_gpio_driver = { |
| 102 | .driver = { |
| 103 | .name = "w1-gpio", |
| 104 | .owner = THIS_MODULE, |
| 105 | }, |
| 106 | .remove = __exit_p(w1_gpio_remove), |
| 107 | }; |
| 108 | |
| 109 | static int __init w1_gpio_init(void) |
| 110 | { |
| 111 | return platform_driver_probe(&w1_gpio_driver, w1_gpio_probe); |
| 112 | } |
| 113 | |
| 114 | static void __exit w1_gpio_exit(void) |
| 115 | { |
| 116 | platform_driver_unregister(&w1_gpio_driver); |
| 117 | } |
| 118 | |
| 119 | module_init(w1_gpio_init); |
| 120 | module_exit(w1_gpio_exit); |
| 121 | |
| 122 | MODULE_DESCRIPTION("GPIO w1 bus master driver"); |
| 123 | MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>"); |
| 124 | MODULE_LICENSE("GPL"); |