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