184 lines
4.3 KiB
C
184 lines
4.3 KiB
C
/*
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* Custom GPIO-based W1 driver
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*
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* Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
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* Copyright (C) 2008 Bifferos <bifferos at yahoo.co.uk>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* ---------------------------------------------------------------------------
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*
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* The behaviour of this driver can be altered by setting some parameters
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* from the insmod command line.
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*
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* The following parameters are adjustable:
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*
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* bus0 These four arguments must be arrays of
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* bus1 3 unsigned integers as follows:
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* bus2
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* bus3 <id>,<pin>,<od>
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*
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* where:
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*
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* <id> ID to used as device_id for the corresponding bus (required)
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* <sda> GPIO pin ID of data pin (required)
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* <od> Pin is configured as open drain.
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*
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* See include/w1-gpio.h for more information about the parameters.
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*
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* If this driver is built into the kernel, you can use the following kernel
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* command line parameters, with the same values as the corresponding module
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* parameters listed above:
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*
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* w1-gpio-custom.bus0
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* w1-gpio-custom.bus1
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* w1-gpio-custom.bus2
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* w1-gpio-custom.bus3
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/w1-gpio.h>
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#define DRV_NAME "w1-gpio-custom"
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#define DRV_DESC "Custom GPIO-based W1 driver"
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#define DRV_VERSION "0.1.1"
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#define PFX DRV_NAME ": "
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#define BUS_PARAM_ID 0
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#define BUS_PARAM_PIN 1
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#define BUS_PARAM_OD 2
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#define BUS_PARAM_REQUIRED 3
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#define BUS_PARAM_COUNT 3
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#define BUS_COUNT_MAX 4
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static unsigned int bus0[BUS_PARAM_COUNT] __initdata;
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static unsigned int bus1[BUS_PARAM_COUNT] __initdata;
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static unsigned int bus2[BUS_PARAM_COUNT] __initdata;
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static unsigned int bus3[BUS_PARAM_COUNT] __initdata;
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static unsigned int bus_nump[BUS_COUNT_MAX] __initdata;
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#define BUS_PARM_DESC " config -> id,pin,od"
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module_param_array(bus0, uint, &bus_nump[0], 0);
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MODULE_PARM_DESC(bus0, "bus0" BUS_PARM_DESC);
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module_param_array(bus1, uint, &bus_nump[1], 0);
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MODULE_PARM_DESC(bus1, "bus1" BUS_PARM_DESC);
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module_param_array(bus2, uint, &bus_nump[2], 0);
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MODULE_PARM_DESC(bus2, "bus2" BUS_PARM_DESC);
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module_param_array(bus3, uint, &bus_nump[3], 0);
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MODULE_PARM_DESC(bus3, "bus3" BUS_PARM_DESC);
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static struct platform_device *devices[BUS_COUNT_MAX];
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static unsigned int nr_devices;
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static void w1_gpio_custom_cleanup(void)
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{
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int i;
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for (i = 0; i < nr_devices; i++)
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if (devices[i])
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platform_device_put(devices[i]);
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}
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static int __init w1_gpio_custom_add_one(unsigned int id, unsigned int *params)
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{
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struct platform_device *pdev;
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struct w1_gpio_platform_data pdata;
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int err;
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if (!bus_nump[id])
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return 0;
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if (bus_nump[id] < BUS_PARAM_REQUIRED) {
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printk(KERN_ERR PFX "not enough parameters for bus%d\n", id);
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err = -EINVAL;
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goto err;
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}
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pdev = platform_device_alloc("w1-gpio", params[BUS_PARAM_ID]);
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if (!pdev) {
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err = -ENOMEM;
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goto err;
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}
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pdata.pin = params[BUS_PARAM_PIN];
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pdata.is_open_drain = params[BUS_PARAM_OD] ? 1:0;
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err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
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if (err)
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goto err_put;
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err = platform_device_add(pdev);
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if (err)
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goto err_put;
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devices[nr_devices++] = pdev;
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return 0;
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err_put:
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platform_device_put(pdev);
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err:
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return err;
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}
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static int __init w1_gpio_custom_probe(void)
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{
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int err;
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nr_devices = 0;
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printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
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err = w1_gpio_custom_add_one(0, bus0);
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if (err) goto err;
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err = w1_gpio_custom_add_one(1, bus1);
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if (err) goto err;
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err = w1_gpio_custom_add_one(2, bus2);
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if (err) goto err;
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err = w1_gpio_custom_add_one(3, bus3);
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if (err) goto err;
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if (!nr_devices) {
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printk(KERN_ERR PFX "no bus parameter(s) specified\n");
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err = -ENODEV;
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goto err;
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}
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return 0;
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err:
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w1_gpio_custom_cleanup();
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return err;
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}
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#ifdef MODULE
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static int __init w1_gpio_custom_init(void)
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{
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return w1_gpio_custom_probe();
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}
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module_init(w1_gpio_custom_init);
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static void __exit w1_gpio_custom_exit(void)
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{
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w1_gpio_custom_cleanup();
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}
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module_exit(w1_gpio_custom_exit);
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#else
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subsys_initcall(w1_gpio_custom_probe);
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#endif /* MODULE*/
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Bifferos <bifferos at yahoo.co.uk >");
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MODULE_DESCRIPTION(DRV_DESC);
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MODULE_VERSION(DRV_VERSION);
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