[PATCH] i2c: i2c-tiny-usb: Add parameter for optional i2c-devices.

[Alexander Holler]

Make it possible to define i2c-devices at the kernel command line
or as a module parameter.

Format is devname1@addr1,devname2@addr2,...

Example for the kernel command line:

   i2c-tiny-usb.devices=ds1307@0x68,pcf8563@0x51

The definition of up to 8 devices is allowed.

Cc: Till Harbaum <till@xxxxxxxxxxx>
Signed-off-by: Alexander Holler <holler@xxxxxxxxxxxxx>
---
 drivers/i2c/busses/i2c-tiny-usb.c |   44 +++++++++++++++++++++++++++++++++++++
 1 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tiny-usb.c b/drivers/i2c/busses/i2c-tiny-usb.c
index 0510636..a3fc711 100644
--- a/drivers/i2c/busses/i2c-tiny-usb.c
+++ b/drivers/i2c/busses/i2c-tiny-usb.c
@@ -40,6 +40,11 @@ module_param(delay, ushort, 0);
 MODULE_PARM_DESC(delay, "bit delay in microseconds "
 		 "(default is 10us for 100kHz max)");
 
+#define MAX_OPTIONAL_I2C_DEVICES 8
+static char *opt_devices[MAX_OPTIONAL_I2C_DEVICES];
+module_param_array_named(devices, opt_devices, charp, NULL, 0);
+MODULE_PARM_DESC(devices, "devname1@adr1,devname2@adr2,... (e.g. ds1307@0x68)");
+
 static int usb_read(struct i2c_adapter *adapter, int cmd,
 		    int value, int index, void *data, int len);
 
@@ -184,6 +189,42 @@ static void i2c_tiny_usb_free(struct i2c_tiny_usb *dev)
 	kfree(dev);
 }
 
+static void i2c_add_optional_devices(struct i2c_adapter *adapter)
+{
+	int i;
+	struct i2c_board_info i2c_info;
+	uint addr;
+	const char *at;
+
+	for (i = 0; opt_devices[i]; ++i) {
+		at = strchr(opt_devices[i], '@');
+		if (at++ == NULL) {
+			dev_warn(&adapter->dev,
+				"address needed in device definition '%s'\n",
+				opt_devices[i]);
+			continue;
+		}
+		if (kstrtouint(at, 0, &addr) || addr >= I2C_CLIENT_END) {
+			dev_warn(&adapter->dev,
+				"wrong address in device definition '%s'\n",
+				opt_devices[i]);
+			continue;
+		}
+		memset(&i2c_info, 0, sizeof(struct i2c_board_info));
+		strlcpy(i2c_info.type, opt_devices[i],
+			min(I2C_NAME_SIZE, (int)(at-opt_devices[i])));
+		i2c_info.addr = addr;
+		if (i2c_new_device(adapter, &i2c_info) != NULL)
+			dev_info(&adapter->dev,
+				"device %s at address 0x%02x registered\n",
+				i2c_info.type, addr);
+		else
+			dev_warn(&adapter->dev,
+				"device %s at address 0x%02x not found\n",
+				i2c_info.type, addr);
+	}
+}
+
 static int i2c_tiny_usb_probe(struct usb_interface *interface,
 			      const struct usb_device_id *id)
 {
@@ -236,6 +277,9 @@ static int i2c_tiny_usb_probe(struct usb_interface *interface,
 	/* inform user about successful attachment to i2c layer */
 	dev_info(&dev->adapter.dev, "connected i2c-tiny-usb device\n");
 
+	/* add optional devices */
+	i2c_add_optional_devices(&dev->adapter);
+
 	return 0;
 
  error:
-- 
1.7.8.6

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