drivers: w1: Extend 1W master driver DS2482 with module option to support PPM/SPU/1WS features

Extend the one wire DS2482 master driver with a module option that allows support
for PPM/SPU/1WS interface modes to be requested. This allows support of chips
that require one or more of these features such as the DS28E05.

Signed-off-by: Andrew Worsley <amworsley@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/w1/masters/ds2482.c

@@ -70,6 +70,8 @@ MODULE_PARM_DESC(active_pullup, "Active pullup (apply to all buses): " \
 #define DS2482_REG_CFG_PPM		0x02	/* presence pulse masking */
 #define DS2482_REG_CFG_APU		0x01	/* active pull-up */
 
+/* extra configurations - e.g. 1WS */
+int extra_config;
 
 /**
  * Write and verify codes for the CHANNEL_SELECT command (DS2482-800 only).
@@ -403,7 +405,7 @@ static u8 ds2482_w1_reset_bus(void *data)
 		/* If the chip did reset since detect, re-config it */
 		if (err & DS2482_REG_STS_RST)
 			ds2482_send_cmd_data(pdev, DS2482_CMD_WRITE_CONFIG,
-					     ds2482_calculate_config(0x00));
+					ds2482_calculate_config(extra_config));
 	}
 
 	mutex_unlock(&pdev->access_lock);
@@ -429,8 +431,7 @@ static u8 ds2482_w1_set_pullup(void *data, int delay)
 		ds2482_wait_1wire_idle(pdev);
 		/* note: it seems like both SPU and APU have to be set! */
 		retval = ds2482_send_cmd_data(pdev, DS2482_CMD_WRITE_CONFIG,
-			ds2482_calculate_config(DS2482_REG_CFG_SPU |
-						DS2482_REG_CFG_APU));
+			ds2482_calculate_config(extra_config|DS2482_REG_CFG_SPU|DS2482_REG_CFG_APU));
 		ds2482_wait_1wire_idle(pdev);
 	}
 
@@ -483,7 +484,7 @@ static int ds2482_probe(struct i2c_client *client,
 
 	/* Set all config items to 0 (off) */
 	ds2482_send_cmd_data(data, DS2482_CMD_WRITE_CONFIG,
-		ds2482_calculate_config(0x00));
+		ds2482_calculate_config(extra_config));
 
 	mutex_init(&data->access_lock);
 
@@ -558,4 +559,7 @@ module_i2c_driver(ds2482_driver);
 
 MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
 MODULE_DESCRIPTION("DS2482 driver");
+module_param(extra_config, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(extra_config, "Extra Configuration settings 1=APU,2=PPM,3=SPU,8=1WS");
+
 MODULE_LICENSE("GPL");