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@ -6,6 +6,40 @@ |
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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 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>,<sda>,<scl>,<udelay>,<timeout>,<sda_od>,<scl_od>,<scl_oo> |
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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 to used for SDA (required) |
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* <scl> GPIO pin ID to used for SCL (required) |
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* <udelay> signal toggle delay. |
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* <timeout> clock stretching timeout. |
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* <sda_od> SDA is configured as open drain. |
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* <scl_od> SCL is configured as open drain. |
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* <scl_oo> SCL output drivers cannot be turned off. |
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* |
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* See include/i2c-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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* i2c-gpio-custom.bus0 |
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* i2c-gpio-custom.bus1 |
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* i2c-gpio-custom.bus2 |
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* i2c-gpio-custom.bus3 |
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*/ |
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#include <linux/kernel.h> |
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@ -16,56 +50,141 @@ |
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#include <linux/i2c-gpio.h> |
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#define DRV_NAME "i2c-gpio-custom" |
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#define DRV_DESC "Custom GPIO I2C device driver" |
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#define DRV_DESC "Custom GPIO-based I2C 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_ID 0 |
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#define BUS_PARAM_SDA 1 |
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#define BUS_PARAM_SCL 2 |
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#define BUS_PARAM_UDELAY 3 |
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#define BUS_PARAM_TIMEOUT 4 |
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#define BUS_PARAM_SDA_OD 5 |
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#define BUS_PARAM_SCL_OD 6 |
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#define BUS_PARAM_SCL_OO 7 |
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#define BUS_PARAM_REQUIRED 3 |
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#define BUS_PARAM_COUNT 8 |
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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,sda,scl[,udelay,timeout,sda_od,scl_od,scl_oo]" |
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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 i2c_gpio_custom_cleanup(void) |
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{ |
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int i; |
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static unsigned int sda = CONFIG_I2C_GPIO_CUSTOM_SDA; |
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static unsigned int scl = CONFIG_I2C_GPIO_CUSTOM_SCL; |
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static int id = CONFIG_I2C_GPIO_CUSTOM_DEVICE_ID; |
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for (i = 0; i < nr_devices; i++) |
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if (devices[i]) |
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platform_device_unregister(devices[i]); |
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} |
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module_param(sda, uint, S_IRUGO); |
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MODULE_PARM_DESC(sda, "GPIO pin for SDA"); |
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static int __init i2c_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 i2c_gpio_platform_data pdata; |
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int err; |
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module_param(scl, uint, S_IRUGO); |
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MODULE_PARM_DESC(scl, "GPIO pin for SCL"); |
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if (!bus_nump[id]) |
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return 0; |
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module_param(id, int, S_IRUGO); |
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MODULE_PARM_DESC(id, "device id of the i2c-gpio device"); |
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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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static struct i2c_gpio_platform_data i2c_data; |
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static struct platform_device i2c_device; |
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pdev = platform_device_alloc("i2c-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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static void i2c_gpio_custom_release(struct platform_device *pdev) |
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{ |
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/* nothing to do */ |
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devices[nr_devices++] = pdev; |
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pdata.sda_pin = params[BUS_PARAM_SDA]; |
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pdata.scl_pin = params[BUS_PARAM_SCL]; |
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pdata.udelay = params[BUS_PARAM_UDELAY]; |
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pdata.timeout = params[BUS_PARAM_TIMEOUT]; |
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pdata.sda_is_open_drain = params[BUS_PARAM_SDA_OD] != 0; |
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pdata.scl_is_open_drain = params[BUS_PARAM_SCL_OD] != 0; |
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pdata.scl_is_output_only = params[BUS_PARAM_SCL_OO] != 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; |
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err = platform_device_register(pdev); |
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if (err) |
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goto err; |
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return 0; |
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err: |
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return err; |
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} |
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static int __init i2c_gpio_custom_init(void) |
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{ |
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int err; |
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i2c_data.sda_pin = sda; |
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i2c_data.scl_pin = scl; |
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printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n"); |
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err = i2c_gpio_custom_add_one(0, bus0); |
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if (err) goto err; |
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i2c_device.name = "i2c-gpio"; |
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i2c_device.id = id; |
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err = i2c_gpio_custom_add_one(1, bus1); |
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if (err) goto err; |
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i2c_device.dev.platform_data = &i2c_data, |
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i2c_device.dev.release = i2c_gpio_custom_release, |
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err = i2c_gpio_custom_add_one(2, bus2); |
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if (err) goto err; |
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err = platform_device_register(&i2c_device); |
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err = i2c_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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i2c_gpio_custom_cleanup(); |
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return err; |
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} |
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module_init(i2c_gpio_custom_init); |
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static void __exit i2c_gpio_custom_exit(void) |
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{ |
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platform_device_unregister(&i2c_device); |
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i2c_gpio_custom_cleanup(); |
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} |
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module_init(i2c_gpio_custom_init); |
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module_exit(i2c_gpio_custom_exit); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org >"); |
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MODULE_DESCRIPTION(DRV_DESC); |
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MODULE_VERSION(DRV_VERSION); |
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