enhance the custom i2c-gpio driver (supports 4 buses from now on), update kernel configuration

SVN-Revision: 9244

1 files changed, 144 insertions, 25 deletions

diff --git a/target/linux/adm5120/files/drivers/i2c/busses/i2c-gpio-custom.c b/target/linux/adm5120/files/drivers/i2c/busses/i2c-gpio-custom.c
index a019faf..9d62a2d 100644
--- a/target/linux/adm5120/files/drivers/i2c/busses/i2c-gpio-custom.c
+++ b/target/linux/adm5120/files/drivers/i2c/busses/i2c-gpio-custom.c
@@ -6,6 +6,40 @@
  *  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.
+ *
+ * ---------------------------------------------------------------------------
+ *
+ *  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>,<sda>,<scl>,<udelay>,<timeout>,<sda_od>,<scl_od>,<scl_oo>
+ *
+ *  where:
+ *
+ *  <id>	ID to used as device_id for the corresponding bus (required)
+ *  <sda>	GPIO pin ID to used for SDA (required)
+ *  <scl>	GPIO pin ID to used for SCL (required)
+ *  <udelay>	signal toggle delay.
+ *  <timeout>	clock stretching timeout.
+ *  <sda_od>	SDA is configured as open drain.
+ *  <scl_od>	SCL is configured as open drain.
+ *  <scl_oo>	SCL output drivers cannot be turned off.
+ *
+ *  See include/i2c-gpio.h for more information about the parameters.
+ *
+ *  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:
+ *
+ *	i2c-gpio-custom.bus0
+ *	i2c-gpio-custom.bus1
+ *	i2c-gpio-custom.bus2
+ *	i2c-gpio-custom.bus3
  */
 
 #include <linux/kernel.h>
@@ -16,56 +50,141 @@
 #include <linux/i2c-gpio.h>
 
 #define DRV_NAME	"i2c-gpio-custom"
-#define DRV_DESC	"Custom GPIO I2C device driver"
+#define DRV_DESC	"Custom GPIO-based I2C driver"
+#define DRV_VERSION	"0.1.0"
+
+#define PFX		DRV_NAME ": "
+
+#define BUS_PARAM_ID		0
+#define BUS_PARAM_SDA		1
+#define BUS_PARAM_SCL		2
+#define BUS_PARAM_UDELAY	3
+#define BUS_PARAM_TIMEOUT	4
+#define BUS_PARAM_SDA_OD	5
+#define BUS_PARAM_SCL_OD	6
+#define BUS_PARAM_SCL_OO	7
+
+#define BUS_PARAM_REQUIRED	3
+#define BUS_PARAM_COUNT		8
+#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,sda,scl[,udelay,timeout,sda_od,scl_od,scl_oo]"
+
+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 i2c_gpio_custom_cleanup(void)
+{
+	int i;
 
-static unsigned int sda = CONFIG_I2C_GPIO_CUSTOM_SDA;
-static unsigned int scl = CONFIG_I2C_GPIO_CUSTOM_SCL;
-static int id = CONFIG_I2C_GPIO_CUSTOM_DEVICE_ID;
+	for (i = 0; i < nr_devices; i++)
+		if (devices[i])
+			platform_device_unregister(devices[i]);
+}
 
-module_param(sda, uint, S_IRUGO);
-MODULE_PARM_DESC(sda, "GPIO pin for SDA");
+static int __init i2c_gpio_custom_add_one(unsigned int id, unsigned int *params)
+{
+	struct platform_device *pdev;
+	struct i2c_gpio_platform_data pdata;
+	int err;
 
-module_param(scl, uint, S_IRUGO);
-MODULE_PARM_DESC(scl, "GPIO pin for SCL");
+	if (!bus_nump[id])
+		return 0;
 
-module_param(id, int, S_IRUGO);
-MODULE_PARM_DESC(id, "device id of the i2c-gpio device");
+	if (bus_nump[id] < BUS_PARAM_REQUIRED) {
+		printk(KERN_ERR PFX "not enough parameters for bus%d\n", id);
+		err = -EINVAL;
+		goto err;
+	}
 
-static struct i2c_gpio_platform_data i2c_data;
-static struct platform_device i2c_device;
+	pdev = platform_device_alloc("i2c-gpio", params[BUS_PARAM_ID]);
+	if (!pdev) {
+		err = -ENOMEM;
+		goto err;
+	}
 
-static void i2c_gpio_custom_release(struct platform_device *pdev)
-{
-	/* nothing to do */
+	devices[nr_devices++] = pdev;
+
+	pdata.sda_pin = params[BUS_PARAM_SDA];
+	pdata.scl_pin = params[BUS_PARAM_SCL];
+	pdata.udelay = params[BUS_PARAM_UDELAY];
+	pdata.timeout = params[BUS_PARAM_TIMEOUT];
+	pdata.sda_is_open_drain = params[BUS_PARAM_SDA_OD] != 0;
+	pdata.scl_is_open_drain = params[BUS_PARAM_SCL_OD] != 0;
+	pdata.scl_is_output_only = params[BUS_PARAM_SCL_OO] != 0;
+
+	err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
+	if (err)
+		goto err;
+
+	err = platform_device_register(pdev);
+	if (err)
+		goto err;
+
+	return 0;
+
+err:
+	return err;
 }
 
 static int __init i2c_gpio_custom_init(void)
 {
 	int err;
 
-	i2c_data.sda_pin = sda;
-	i2c_data.scl_pin = scl;
+	printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
+
+	err = i2c_gpio_custom_add_one(0, bus0);
+	if (err) goto err;
 
-	i2c_device.name	= "i2c-gpio";
-	i2c_device.id	= id;
+	err = i2c_gpio_custom_add_one(1, bus1);
+	if (err) goto err;
 
-	i2c_device.dev.platform_data	= &i2c_data,
-	i2c_device.dev.release		= i2c_gpio_custom_release,
+	err = i2c_gpio_custom_add_one(2, bus2);
+	if (err) goto err;
 
-	err = platform_device_register(&i2c_device);
+	err = i2c_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:
+	i2c_gpio_custom_cleanup();
 	return err;
 }
+module_init(i2c_gpio_custom_init);
 
 static void __exit i2c_gpio_custom_exit(void)
 {
-	platform_device_unregister(&i2c_device);
+	i2c_gpio_custom_cleanup();
 }
-
-module_init(i2c_gpio_custom_init);
 module_exit(i2c_gpio_custom_exit);
 
+
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org >");
 MODULE_DESCRIPTION(DRV_DESC);
+MODULE_VERSION(DRV_VERSION);