11 #include <linux/i2c-algo-bit.h>
12 #include <linux/i2c-gpio.h>
26 		gpio_direction_input(pdata->sda_pin);  in i2c_gpio_setsda_dir()
28 		gpio_direction_output(pdata->sda_pin, 0);  in i2c_gpio_setsda_dir()
32  * Toggle SDA by changing the output value of the pin. This is only
34  * high effectively turns off the output driver.)
40 	gpio_set_value(pdata->sda_pin, state);  in i2c_gpio_setsda_val()
49 		gpio_direction_input(pdata->scl_pin);  in i2c_gpio_setscl_dir()
51 		gpio_direction_output(pdata->scl_pin, 0);  in i2c_gpio_setscl_dir()
55  * Toggle SCL by changing the output value of the pin. This is used
56  * for pins that are configured as open drain and for output-only
64 	gpio_set_value(pdata->scl_pin, state);  in i2c_gpio_setscl_val()
71 	return gpio_get_value(pdata->sda_pin);  in i2c_gpio_getsda()
78 	return gpio_get_value(pdata->scl_pin);  in i2c_gpio_getscl()
88 	pdata = pdev->dev.platform_data;  in i2c_gpio_probe()
90 		return -ENXIO;  in i2c_gpio_probe()
92 	ret = -ENOMEM;  in i2c_gpio_probe()
100 	ret = gpio_request(pdata->sda_pin, "sda");  in i2c_gpio_probe()
103 	ret = gpio_request(pdata->scl_pin, "scl");  in i2c_gpio_probe()
107 	if (pdata->sda_is_open_drain) {  in i2c_gpio_probe()
108 		gpio_direction_output(pdata->sda_pin, 1);  in i2c_gpio_probe()
109 		bit_data->setsda = i2c_gpio_setsda_val;  in i2c_gpio_probe()
111 		gpio_direction_input(pdata->sda_pin);  in i2c_gpio_probe()
112 		bit_data->setsda = i2c_gpio_setsda_dir;  in i2c_gpio_probe()
115 	if (pdata->scl_is_open_drain || pdata->scl_is_output_only) {  in i2c_gpio_probe()
116 		gpio_direction_output(pdata->scl_pin, 1);  in i2c_gpio_probe()
117 		bit_data->setscl = i2c_gpio_setscl_val;  in i2c_gpio_probe()
119 		gpio_direction_input(pdata->scl_pin);  in i2c_gpio_probe()
120 		bit_data->setscl = i2c_gpio_setscl_dir;  in i2c_gpio_probe()
123 	if (!pdata->scl_is_output_only)  in i2c_gpio_probe()
124 		bit_data->getscl = i2c_gpio_getscl;  in i2c_gpio_probe()
125 	bit_data->getsda = i2c_gpio_getsda;  in i2c_gpio_probe()
127 	if (pdata->udelay)  in i2c_gpio_probe()
128 		bit_data->udelay = pdata->udelay;  in i2c_gpio_probe()
129 	else if (pdata->scl_is_output_only)  in i2c_gpio_probe()
130 		bit_data->udelay = 50;			/* 10 kHz */  in i2c_gpio_probe()
132 		bit_data->udelay = 5;			/* 100 kHz */  in i2c_gpio_probe()
134 	if (pdata->timeout)  in i2c_gpio_probe()
135 		bit_data->timeout = pdata->timeout;  in i2c_gpio_probe()
137 		bit_data->timeout = HZ / 10;		/* 100 ms */  in i2c_gpio_probe()
139 	bit_data->data = pdata;  in i2c_gpio_probe()
141 	adap->owner = THIS_MODULE;  in i2c_gpio_probe()
142 	snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);  in i2c_gpio_probe()
143 	adap->algo_data = bit_data;  in i2c_gpio_probe()
144 	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;  in i2c_gpio_probe()
145 	adap->dev.parent = &pdev->dev;  in i2c_gpio_probe()
148 	 * If "dev->id" is negative we consider it as zero.  in i2c_gpio_probe()
149 	 * The reason to do so is to avoid sysfs names that only make  in i2c_gpio_probe()
152 	adap->nr = (pdev->id != -1) ? pdev->id : 0;  in i2c_gpio_probe()
159 	dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",  in i2c_gpio_probe()
160 		 pdata->sda_pin, pdata->scl_pin,  in i2c_gpio_probe()
161 		 pdata->scl_is_output_only  in i2c_gpio_probe()
162 		 ? ", no clock stretching" : "");  in i2c_gpio_probe()
167 	gpio_free(pdata->scl_pin);  in i2c_gpio_probe()
169 	gpio_free(pdata->sda_pin);  in i2c_gpio_probe()
184 	pdata = pdev->dev.platform_data;  in i2c_gpio_remove()
187 	gpio_free(pdata->scl_pin);  in i2c_gpio_remove()
188 	gpio_free(pdata->sda_pin);  in i2c_gpio_remove()
189 	kfree(adap->algo_data);  in i2c_gpio_remove()
197 		.name	= "i2c-gpio",
210 		printk(KERN_ERR "i2c-gpio: probe failed: %d\n", ret);  in i2c_gpio_init()
223 MODULE_DESCRIPTION("Platform-independent bitbanging I2C driver");
225 MODULE_ALIAS("platform:i2c-gpio");