194 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			194 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  Custom GPIO-based rotary driver
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 *
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 *  Copyright (C) 2010 Claudio Mignanti <c.mignanti@gmail.com>
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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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 *  Strongly based on Custom GPIO-based I2C driver by:
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 *  Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
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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 can be arrays of
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 *	bus1	1-8 unsigned integers as follows:
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 *	bus2
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 *	bus3	<id>,<steps>,<axis>,<gpioa>,<gpiob>,<inverted>
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 *
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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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 *	rotary-gpio-custom.bus0
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 *	rotary-gpio-custom.bus1
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 *	rotary-gpio-custom.bus2
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 *	rotary-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/input.h>
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#include <linux/platform_device.h>
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#include <linux/rotary_encoder.h>
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#define DRV_NAME	"rotary-gpio-custom"
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#define DRV_DESC	"Custom GPIO-based rotary driver"
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#define DRV_VERSION	"0.1.0"
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#define PFX		DRV_NAME ": "
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#define BUS_PARAM_REQUIRED	5
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#define BUS_PARAM_COUNT		6
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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 \
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	" config -> id,steps,axis,gpioa,gpiob[,inverted]"
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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 rotary_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 rotary_gpio_custom_add_one(unsigned int id,
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					     unsigned int *params)
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{
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	struct platform_device *pdev;
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	struct rotary_encoder_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("rotary-gpio", params[0]);
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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.steps = params[1];
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	pdata.axis = params[2];
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	pdata.relative_axis = false;
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	pdata.rollover = false;
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	pdata.gpio_a = params[3];
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	pdata.gpio_b = params[4];
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	if (params[5] == 1) {
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		pdata.inverted_a = 1;
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		pdata.inverted_b = 1;
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	} else {
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		pdata.inverted_a = 0;
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		pdata.inverted_b = 0;
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	}
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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 rotary_gpio_custom_probe(void)
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{
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	int err;
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	printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
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	err = rotary_gpio_custom_add_one(0, bus0);
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	if (err)
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		goto err;
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	err = rotary_gpio_custom_add_one(1, bus1);
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	if (err)
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		goto err;
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	err = rotary_gpio_custom_add_one(2, bus2);
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	if (err)
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		goto err;
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	err = rotary_gpio_custom_add_one(3, bus3);
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	if (err)
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		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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	rotary_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 rotary_gpio_custom_init(void)
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{
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	return rotary_gpio_custom_probe();
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}
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module_init(rotary_gpio_custom_init);
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static void __exit rotary_gpio_custom_exit(void)
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{
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	rotary_gpio_custom_cleanup();
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}
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module_exit(rotary_gpio_custom_exit);
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#else
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subsys_initcall(rotary_gpio_custom_probe);
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#endif /* MODULE*/
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org >");
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MODULE_AUTHOR("Claudio Mignanti <c.mignanti@gmail.com>");
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MODULE_DESCRIPTION(DRV_DESC);
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MODULE_VERSION(DRV_VERSION);
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