trunk-47381HEADmaster

1 files changed, 202 insertions, 0 deletions

diff --git a/package/kernel/i2c-gpio-custom/src/i2c-gpio-custom.c b/package/kernel/i2c-gpio-custom/src/i2c-gpio-custom.c
new file mode 100644
index 0000000..921d290
--- /dev/null
+++ b/package/kernel/i2c-gpio-custom/src/i2c-gpio-custom.c
@@ -0,0 +1,202 @@
+/*
+ *  Custom GPIO-based I2C driver
+ *
+ *  Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  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>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+
+#include <linux/i2c-gpio.h>
+
+#define DRV_NAME	"i2c-gpio-custom"
+#define DRV_DESC	"Custom GPIO-based I2C driver"
+#define DRV_VERSION	"0.1.1"
+
+#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;
+
+	for (i = 0; i < nr_devices; i++)
+		if (devices[i])
+			platform_device_put(devices[i]);
+}
+
+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;
+
+	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("i2c-gpio", params[BUS_PARAM_ID]);
+	if (!pdev) {
+		err = -ENOMEM;
+		goto err;
+	}
+
+	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_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 i2c_gpio_custom_probe(void)
+{
+	int err;
+
+	printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
+
+	err = i2c_gpio_custom_add_one(0, bus0);
+	if (err)
+		goto err;
+
+	err = i2c_gpio_custom_add_one(1, bus1);
+	if (err)
+		goto err;
+
+	err = i2c_gpio_custom_add_one(2, bus2);
+	if (err)
+		goto err;
+
+	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;
+}
+
+#ifdef MODULE
+static int __init i2c_gpio_custom_init(void)
+{
+	return i2c_gpio_custom_probe();
+}
+module_init(i2c_gpio_custom_init);
+
+static void __exit i2c_gpio_custom_exit(void)
+{
+	i2c_gpio_custom_cleanup();
+}
+module_exit(i2c_gpio_custom_exit);
+#else
+subsys_initcall(i2c_gpio_custom_probe);
+#endif /* MODULE*/
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org >");
+MODULE_DESCRIPTION(DRV_DESC);
+MODULE_VERSION(DRV_VERSION);