[PATCH] hwmon/lm70: adding support for NS LM74 chip

From: Christophe Leroy
Date: Thu Aug 23 2012 - 11:32:15 EST


Hello,

This Patch adds support for the LM74 chip from National Semiconductor (NS)
in the lm70 driver

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>

diff -u linux-3.5-vanilla/drivers/hwmon/Kconfig linux-3.5/drivers/hwmon/Kconfig
--- linux-3.5-vanilla/drivers/hwmon/Kconfig 2012-07-21 22:58:29.000000000 +0200
+++ linux-3.5/drivers/hwmon/Kconfig 2012-08-21 13:46:47.000000000 +0200
@@ -530,11 +530,11 @@
will be called lm63.

config SENSORS_LM70
- tristate "National Semiconductor LM70 / Texas Instruments TMP121"
+ tristate "National Semiconductor LM70&LM74 / Texas Instruments TMP121"
depends on SPI_MASTER
help
If you say yes here you get support for the National Semiconductor
- LM70 and Texas Instruments TMP121/TMP123 digital temperature
+ LM70 and LM74 and Texas Instruments TMP121/TMP123 digital temperature
sensor chips.

This driver can also be built as a module. If so, the module
diff -u linux-3.5-vanilla/drivers/hwmon/lm70.c linux-3.5/drivers/hwmon/lm70.c
--- linux-3.5-vanilla/drivers/hwmon/lm70.c 2012-07-21 22:58:29.000000000 +0200
+++ linux-3.5/drivers/hwmon/lm70.c 2012-08-21 13:46:31.000000000 +0200
@@ -3,11 +3,12 @@
*
* The LM70 is a temperature sensor chip from National Semiconductor (NS).
* Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@xxxxxxxxxxxxxxxxxxx>
+ * Copyright (C) 2012 Christophe Leroy <christophe.leroy@xxxxxx>
*
* The LM70 communicates with a host processor via an SPI/Microwire Bus
* interface. The complete datasheet is available at National's website
* here:
- * http://www.national.com/pf/LM/LM70.html
+ * http://www.ti.com/product/LM70
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -43,6 +44,7 @@

#define LM70_CHIP_LM70 0 /* original NS LM70 */
#define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */
+#define LM70_CHIP_LM74 2 /* original NS LM74 */

struct lm70 {
struct device *hwmon_dev;
@@ -98,6 +100,7 @@
break;

case LM70_CHIP_TMP121:
+ case LM70_CHIP_LM74:
val = ((int)raw / 8) * 625 / 10;
break;
}
@@ -123,6 +126,9 @@
case LM70_CHIP_TMP121:
ret = sprintf(buf, "tmp121\n");
break;
+ case LM70_CHIP_LM74:
+ ret = sprintf(buf, "lm74\n");
+ break;
default:
ret = -EINVAL;
}
@@ -139,12 +145,13 @@
struct lm70 *p_lm70;
int status;

- /* signaling is SPI_MODE_0 for both LM70 and TMP121 */
+ /* signaling is SPI_MODE_0 for LM70, LM74 and TMP121 */
if (spi->mode & (SPI_CPOL | SPI_CPHA))
return -EINVAL;

- /* 3-wire link (shared SI/SO) for LM70 */
- if (chip == LM70_CHIP_LM70 && !(spi->mode & SPI_3WIRE))
+ /* 3-wire link (shared SI/SO) for LM70 and LM74 */
+ if ((chip == LM70_CHIP_LM70 || chip == LM70_CHIP_LM74)
+ && !(spi->mode & SPI_3WIRE))
return -EINVAL;

/* NOTE: we assume 8-bit words, and convert to 16 bits manually */
@@ -202,6 +209,7 @@
static const struct spi_device_id lm70_ids[] = {
{ "lm70", LM70_CHIP_LM70 },
{ "tmp121", LM70_CHIP_TMP121 },
+ { "lm74", LM70_CHIP_LM74 },
{ },
};
MODULE_DEVICE_TABLE(spi, lm70_ids);
@@ -219,5 +227,5 @@
module_spi_driver(lm70_driver);

MODULE_AUTHOR("Kaiwan N Billimoria");
-MODULE_DESCRIPTION("NS LM70 / TI TMP121/TMP123 Linux driver");
+MODULE_DESCRIPTION("NS LM70 & LM74 / TI TMP121/TMP123 Linux driver");
MODULE_LICENSE("GPL");
diff -u linux-3.5-vanilla/Documentation/hwmon/lm70 linux-3.5/Documentation/hwmon/lm70
--- linux-3.5-vanilla/Documentation/hwmon/lm70 2012-07-21 22:58:29.000000000 +0200
+++ linux-3.5/Documentation/hwmon/lm70 2012-08-21 13:38:24.000000000 +0200
@@ -3,7 +3,9 @@

Supported chips:
* National Semiconductor LM70
- Datasheet: http://www.national.com/pf/LM/LM70.html
+ Datasheet: http://www.ti.com/product/LM70
+ * National Semiconductor LM74
+ Datasheet: http://www.ti.com/product/LM74
* Texas Instruments TMP121/TMP123
Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html

@@ -31,9 +33,11 @@
with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c
and its associated documentation.

-The TMP121/TMP123 are very similar; main differences are 4 wire SPI inter-
-face (read only) and 13-bit temperature data (0.0625 degrees celsius reso-
-lution).
+The LM74 is very similar; main differences is 13-bit temperature data
+(0.0625 degrees celsius resolution).
+
+The TMP121/TMP123 are very similar to the LM74; main difference is 4 wire
+SPI interface (read only).

Thanks to
---------
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