diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/i2c/busses/i2c-gpio.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/i2c/busses/i2c-gpio.c | 279 |
1 files changed, 0 insertions, 279 deletions
diff --git a/ANDROID_3.4.5/drivers/i2c/busses/i2c-gpio.c b/ANDROID_3.4.5/drivers/i2c/busses/i2c-gpio.c deleted file mode 100644 index c0330a41..00000000 --- a/ANDROID_3.4.5/drivers/i2c/busses/i2c-gpio.c +++ /dev/null @@ -1,279 +0,0 @@ -/* - * Bitbanging I2C bus driver using the GPIO API - * - * Copyright (C) 2007 Atmel Corporation - * - * 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. - */ -#include <linux/i2c.h> -#include <linux/i2c-algo-bit.h> -#include <linux/i2c-gpio.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/platform_device.h> -#include <linux/gpio.h> -#include <linux/of_gpio.h> -#include <linux/of_i2c.h> - -struct i2c_gpio_private_data { - struct i2c_adapter adap; - struct i2c_algo_bit_data bit_data; - struct i2c_gpio_platform_data pdata; -}; - -/* Toggle SDA by changing the direction of the pin */ -static void i2c_gpio_setsda_dir(void *data, int state) -{ - struct i2c_gpio_platform_data *pdata = data; - - if (state) - gpio_direction_input(pdata->sda_pin); - else - gpio_direction_output(pdata->sda_pin, 0); -} - -/* - * Toggle SDA by changing the output value of the pin. This is only - * valid for pins configured as open drain (i.e. setting the value - * high effectively turns off the output driver.) - */ -static void i2c_gpio_setsda_val(void *data, int state) -{ - struct i2c_gpio_platform_data *pdata = data; - - gpio_set_value(pdata->sda_pin, state); -} - -/* Toggle SCL by changing the direction of the pin. */ -static void i2c_gpio_setscl_dir(void *data, int state) -{ - struct i2c_gpio_platform_data *pdata = data; - - if (state) - gpio_direction_input(pdata->scl_pin); - else - gpio_direction_output(pdata->scl_pin, 0); -} - -/* - * Toggle SCL by changing the output value of the pin. This is used - * for pins that are configured as open drain and for output-only - * pins. The latter case will break the i2c protocol, but it will - * often work in practice. - */ -static void i2c_gpio_setscl_val(void *data, int state) -{ - struct i2c_gpio_platform_data *pdata = data; - - gpio_set_value(pdata->scl_pin, state); -} - -static int i2c_gpio_getsda(void *data) -{ - struct i2c_gpio_platform_data *pdata = data; - - return gpio_get_value(pdata->sda_pin); -} - -static int i2c_gpio_getscl(void *data) -{ - struct i2c_gpio_platform_data *pdata = data; - - return gpio_get_value(pdata->scl_pin); -} - -static int __devinit of_i2c_gpio_probe(struct device_node *np, - struct i2c_gpio_platform_data *pdata) -{ - u32 reg; - - if (of_gpio_count(np) < 2) - return -ENODEV; - - pdata->sda_pin = of_get_gpio(np, 0); - pdata->scl_pin = of_get_gpio(np, 1); - - if (!gpio_is_valid(pdata->sda_pin) || !gpio_is_valid(pdata->scl_pin)) { - pr_err("%s: invalid GPIO pins, sda=%d/scl=%d\n", - np->full_name, pdata->sda_pin, pdata->scl_pin); - return -ENODEV; - } - - of_property_read_u32(np, "i2c-gpio,delay-us", &pdata->udelay); - - if (!of_property_read_u32(np, "i2c-gpio,timeout-ms", ®)) - pdata->timeout = msecs_to_jiffies(reg); - - pdata->sda_is_open_drain = - of_property_read_bool(np, "i2c-gpio,sda-open-drain"); - pdata->scl_is_open_drain = - of_property_read_bool(np, "i2c-gpio,scl-open-drain"); - pdata->scl_is_output_only = - of_property_read_bool(np, "i2c-gpio,scl-output-only"); - - return 0; -} - -static int __devinit i2c_gpio_probe(struct platform_device *pdev) -{ - struct i2c_gpio_private_data *priv; - struct i2c_gpio_platform_data *pdata; - struct i2c_algo_bit_data *bit_data; - struct i2c_adapter *adap; - int ret; - - priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); - if (!priv) - return -ENOMEM; - adap = &priv->adap; - bit_data = &priv->bit_data; - pdata = &priv->pdata; - - if (pdev->dev.of_node) { - ret = of_i2c_gpio_probe(pdev->dev.of_node, pdata); - if (ret) - return ret; - } else { - if (!pdev->dev.platform_data) - return -ENXIO; - memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata)); - } - - ret = gpio_request(pdata->sda_pin, "sda"); - if (ret) - goto err_request_sda; - ret = gpio_request(pdata->scl_pin, "scl"); - if (ret) - goto err_request_scl; - - if (pdata->sda_is_open_drain) { - gpio_direction_output(pdata->sda_pin, 1); - bit_data->setsda = i2c_gpio_setsda_val; - } else { - gpio_direction_input(pdata->sda_pin); - bit_data->setsda = i2c_gpio_setsda_dir; - } - - if (pdata->scl_is_open_drain || pdata->scl_is_output_only) { - gpio_direction_output(pdata->scl_pin, 1); - bit_data->setscl = i2c_gpio_setscl_val; - } else { - gpio_direction_input(pdata->scl_pin); - bit_data->setscl = i2c_gpio_setscl_dir; - } - - if (!pdata->scl_is_output_only) - bit_data->getscl = i2c_gpio_getscl; - bit_data->getsda = i2c_gpio_getsda; - - if (pdata->udelay) - bit_data->udelay = pdata->udelay; - else if (pdata->scl_is_output_only) - bit_data->udelay = 50; /* 10 kHz */ - else - bit_data->udelay = 5; /* 100 kHz */ - - if (pdata->timeout) - bit_data->timeout = pdata->timeout; - else - bit_data->timeout = HZ / 10; /* 100 ms */ - - bit_data->data = pdata; - - adap->owner = THIS_MODULE; - snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id); - adap->algo_data = bit_data; - adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; - adap->dev.parent = &pdev->dev; - adap->dev.of_node = pdev->dev.of_node; - - /* - * If "dev->id" is negative we consider it as zero. - * The reason to do so is to avoid sysfs names that only make - * sense when there are multiple adapters. - */ - adap->nr = (pdev->id != -1) ? pdev->id : 0; - ret = i2c_bit_add_numbered_bus(adap); - if (ret) - goto err_add_bus; - - of_i2c_register_devices(adap); - - platform_set_drvdata(pdev, priv); - - dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n", - pdata->sda_pin, pdata->scl_pin, - pdata->scl_is_output_only - ? ", no clock stretching" : ""); - - return 0; - -err_add_bus: - gpio_free(pdata->scl_pin); -err_request_scl: - gpio_free(pdata->sda_pin); -err_request_sda: - return ret; -} - -static int __devexit i2c_gpio_remove(struct platform_device *pdev) -{ - struct i2c_gpio_private_data *priv; - struct i2c_gpio_platform_data *pdata; - struct i2c_adapter *adap; - - priv = platform_get_drvdata(pdev); - adap = &priv->adap; - pdata = &priv->pdata; - - i2c_del_adapter(adap); - gpio_free(pdata->scl_pin); - gpio_free(pdata->sda_pin); - - return 0; -} - -#if defined(CONFIG_OF) -static const struct of_device_id i2c_gpio_dt_ids[] = { - { .compatible = "i2c-gpio", }, - { /* sentinel */ } -}; - -MODULE_DEVICE_TABLE(of, i2c_gpio_dt_ids); -#endif - -static struct platform_driver i2c_gpio_driver = { - .driver = { - .name = "i2c-gpio", - .owner = THIS_MODULE, - .of_match_table = of_match_ptr(i2c_gpio_dt_ids), - }, - .probe = i2c_gpio_probe, - .remove = __devexit_p(i2c_gpio_remove), -}; - -static int __init i2c_gpio_init(void) -{ - int ret; - - ret = platform_driver_register(&i2c_gpio_driver); - if (ret) - printk(KERN_ERR "i2c-gpio: probe failed: %d\n", ret); - - return ret; -} -subsys_initcall(i2c_gpio_init); - -static void __exit i2c_gpio_exit(void) -{ - platform_driver_unregister(&i2c_gpio_driver); -} -module_exit(i2c_gpio_exit); - -MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); -MODULE_DESCRIPTION("Platform-independent bitbanging I2C driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:i2c-gpio"); |