diff options
Diffstat (limited to 'package/kernel/w1-gpio-custom/src/w1-gpio-custom.c')
| -rw-r--r-- | package/kernel/w1-gpio-custom/src/w1-gpio-custom.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/package/kernel/w1-gpio-custom/src/w1-gpio-custom.c b/package/kernel/w1-gpio-custom/src/w1-gpio-custom.c new file mode 100644 index 0000000..96cfcab --- /dev/null +++ b/package/kernel/w1-gpio-custom/src/w1-gpio-custom.c @@ -0,0 +1,185 @@ +/* + * Custom GPIO-based W1 driver + * + * Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org> + * Copyright (C) 2008 Bifferos <bifferos at yahoo.co.uk> + * + * 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. + * + * --------------------------------------------------------------------------- + * + * The behaviour of this driver can be altered by setting some parameters + * from the insmod command line. + * + * The following parameters are adjustable: + * + * bus0 These four arguments must be arrays of + * bus1 3 unsigned integers as follows: + * bus2 + * bus3 <id>,<pin>,<od> + * + * where: + * + * <id> ID to used as device_id for the corresponding bus (required) + * <sda> GPIO pin ID of data pin (required) + * <od> Pin is configured as open drain. + * + * See include/w1-gpio.h for more information about the parameters. + * + * If this driver is built into the kernel, you can use the following kernel + * command line parameters, with the same values as the corresponding module + * parameters listed above: + * + * w1-gpio-custom.bus0 + * w1-gpio-custom.bus1 + * w1-gpio-custom.bus2 + * w1-gpio-custom.bus3 + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> + +#include <linux/w1-gpio.h> + +#define DRV_NAME "w1-gpio-custom" +#define DRV_DESC "Custom GPIO-based W1 driver" +#define DRV_VERSION "0.1.1" + +#define PFX DRV_NAME ": " + +#define BUS_PARAM_ID 0 +#define BUS_PARAM_PIN 1 +#define BUS_PARAM_OD 2 + +#define BUS_PARAM_REQUIRED 3 +#define BUS_PARAM_COUNT 3 +#define BUS_COUNT_MAX 4 + +static unsigned int bus0[BUS_PARAM_COUNT] __initdata; +static unsigned int bus1[BUS_PARAM_COUNT] __initdata; +static unsigned int bus2[BUS_PARAM_COUNT] __initdata; +static unsigned int bus3[BUS_PARAM_COUNT] __initdata; + +static unsigned int bus_nump[BUS_COUNT_MAX] __initdata; + +#define BUS_PARM_DESC " config -> id,pin,od" + +module_param_array(bus0, uint, &bus_nump[0], 0); +MODULE_PARM_DESC(bus0, "bus0" BUS_PARM_DESC); +module_param_array(bus1, uint, &bus_nump[1], 0); +MODULE_PARM_DESC(bus1, "bus1" BUS_PARM_DESC); +module_param_array(bus2, uint, &bus_nump[2], 0); +MODULE_PARM_DESC(bus2, "bus2" BUS_PARM_DESC); +module_param_array(bus3, uint, &bus_nump[3], 0); +MODULE_PARM_DESC(bus3, "bus3" BUS_PARM_DESC); + +static struct platform_device *devices[BUS_COUNT_MAX]; +static unsigned int nr_devices; + +static void w1_gpio_custom_cleanup(void) +{ + int i; + + for (i = 0; i < nr_devices; i++) + if (devices[i]) + platform_device_put(devices[i]); +} + +static int __init w1_gpio_custom_add_one(unsigned int id, unsigned int *params) +{ + struct platform_device *pdev; + struct w1_gpio_platform_data pdata; + int err; + + if (!bus_nump[id]) + return 0; + + if (bus_nump[id] < BUS_PARAM_REQUIRED) { + printk(KERN_ERR PFX "not enough parameters for bus%d\n", id); + err = -EINVAL; + goto err; + } + + pdev = platform_device_alloc("w1-gpio", params[BUS_PARAM_ID]); + if (!pdev) { + err = -ENOMEM; + goto err; + } + + pdata.pin = params[BUS_PARAM_PIN]; + pdata.is_open_drain = params[BUS_PARAM_OD] ? 1:0; + pdata.enable_external_pullup = NULL; + + err = platform_device_add_data(pdev, &pdata, sizeof(pdata)); + if (err) + goto err_put; + + err = platform_device_add(pdev); + if (err) + goto err_put; + + devices[nr_devices++] = pdev; + return 0; + + err_put: + platform_device_put(pdev); + err: + return err; +} + +static int __init w1_gpio_custom_probe(void) +{ + int err; + + nr_devices = 0; + printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n"); + + err = w1_gpio_custom_add_one(0, bus0); + if (err) goto err; + + err = w1_gpio_custom_add_one(1, bus1); + if (err) goto err; + + err = w1_gpio_custom_add_one(2, bus2); + if (err) goto err; + + err = w1_gpio_custom_add_one(3, bus3); + if (err) goto err; + + if (!nr_devices) { + printk(KERN_ERR PFX "no bus parameter(s) specified\n"); + err = -ENODEV; + goto err; + } + + return 0; + +err: + w1_gpio_custom_cleanup(); + return err; +} + +#ifdef MODULE +static int __init w1_gpio_custom_init(void) +{ + return w1_gpio_custom_probe(); +} +module_init(w1_gpio_custom_init); + +static void __exit w1_gpio_custom_exit(void) +{ + w1_gpio_custom_cleanup(); +} +module_exit(w1_gpio_custom_exit); +#else +subsys_initcall(w1_gpio_custom_probe); +#endif /* MODULE*/ + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Bifferos <bifferos at yahoo.co.uk >"); +MODULE_DESCRIPTION(DRV_DESC); +MODULE_VERSION(DRV_VERSION); |