Hello again,
I wrote:
> On Thu, Oct 23, 2008 at 03:20:30PM +0200, Jean Delvare wrote:
> > On Thu, 23 Oct 2008 15:13:23 +0200, Manuel Lauss wrote:
> > > On Thu, Oct 23, 2008 at 02:57:10PM +0200, Jean Delvare wrote:
> > > > I don't know much about the SPI side of things so I would like someone
> > > > else to comment on that aspect of the patch (in particular the way
> > > > different device types are supported by the same driver.) David, can
> > > > you please take a look and let us know if you have any objection?
> > >
> > > I'd be more than happy to just use a number cast to void * for
> > > spi platform_data and get rid of this header. I'm not sure however
> > > whether this is acceptable style for kernel code.
> >
> > Err, no, that's not what I was suggesting. Abusing pointers to store
> > integers is bad, please don't do that.
> >
> > I was more curious about the need to have such arbitrary numbers to
> > differentiate between chip types. For i2c, we can just tell a driver to
> > support several chip names. But maybe the spi subsystem doesn't support
> > that.
>
> Ah, yes, the lack of an i2c_driver.id_table parameter was why I originally
> wrote a separate driver. I suppose I could add another struct spi_driver
> for the TMP121 and sort out chip types internally.
Does this look acceptable?
---
From: Manuel Lauss <mano at roarinelk.homelinux.net>
Subject: [PATCH] hwmon: Extend LM70 with TMP121/TMP123 support.
The Texas Instruments TMP121 is a SPI temperature sensor very similar
to the LM70, with slightly higher resolution. This patch extends the
LM70 driver to support the TMP121.
Signed-off-by: Manuel Lauss <mano at roarinelk.homelinux.net>
---
Documentation/hwmon/lm70 | 7 +++-
drivers/hwmon/Kconfig | 5 ++-
drivers/hwmon/lm70.c | 85 +++++++++++++++++++++++++++++++++++++++-------
3 files changed, 81 insertions(+), 16 deletions(-)
diff --git a/Documentation/hwmon/lm70 b/Documentation/hwmon/lm70
index 2bdd3fe..80716d2 100644
--- a/Documentation/hwmon/lm70
+++ b/Documentation/hwmon/lm70
@@ -1,9 +1,11 @@
Kernel driver lm70
==================
-Supported chip:
+Supported chips:
* National Semiconductor LM70
Datasheet: http://www.national.com/pf/LM/LM70.html
+ * Texas Instruments TMP121/TMP123
+ Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html
Author:
Kaiwan N Billimoria <kaiwan at designergraphix.com>
@@ -25,6 +27,9 @@ complement digital temperature (sent via the SIO line), is available in the
driver for interpretation. This driver makes use of the kernel's in-core
SPI support.
+The TMP121 is very similar; main differences are 4 wire SPI interface
+and 13-bit temperature data (0.0625 degrees celsius resolution).
+
Thanks to
---------
Jean Delvare <khali at linux-fr.org> for mentoring the hwmon-side driver
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 6de1e0f..f86923d 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -407,11 +407,12 @@ config SENSORS_LM63
will be called lm63.
config SENSORS_LM70
- tristate "National Semiconductor LM70"
+ tristate "National Semiconductor LM70 / Texas Instruments TMP121"
depends on SPI_MASTER && EXPERIMENTAL
help
If you say yes here you get support for the National Semiconductor
- LM70 digital temperature sensor chip.
+ LM70 and Texas Instruments TMP121/TMP123 digital temperature
+ sensor chips.
This driver can also be built as a module. If so, the module
will be called lm70.
diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c
index d435f00..8c7651b 100644
--- a/drivers/hwmon/lm70.c
+++ b/drivers/hwmon/lm70.c
@@ -37,9 +37,13 @@
#define DRVNAME "lm70"
+#define LM70_CHIP_LM70 0
+#define LM70_CHIP_TMP121 1
+
struct lm70 {
struct device *hwmon_dev;
struct mutex lock;
+ unsigned int chip;
};
/* sysfs hook function */
@@ -47,7 +51,7 @@ static ssize_t lm70_sense_temp(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct spi_device *spi = to_spi_device(dev);
- int status, val;
+ int status, val = 0;
u8 rxbuf[2];
s16 raw=0;
struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev);
@@ -67,10 +71,8 @@ static ssize_t lm70_sense_temp(struct device *dev,
}
dev_dbg(dev, "rxbuf[1] : 0x%x rxbuf[0] : 0x%x\n", rxbuf[1], rxbuf[0]);
- raw = (rxbuf[1] << 8) + rxbuf[0];
- dev_dbg(dev, "raw=0x%x\n", raw);
-
/*
+ * LM70:
* The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
* complement value. Only the MSB 11 bits (1 sign + 10 temperature
* bits) are meaningful; the LSB 5 bits are to be discarded.
@@ -80,8 +82,23 @@ static ssize_t lm70_sense_temp(struct device *dev,
* by 0.25. Also multiply by 1000 to represent in millidegrees
* Celsius.
* So it's equivalent to multiplying by 0.25 * 1000 = 250.
+ *
+ * TMP121:
+ * 13 bits of 2's complement data, discard LSB 3 bits. Chip
+ * transmits high byte first. Resolution 0.0625 degrees celsius.
*/
- val = ((int)raw/32) * 250;
+ switch (p_lm70->chip) {
+ case LM70_CHIP_LM70:
+ raw = (rxbuf[1] << 8) + rxbuf[0];
+ val = ((int)raw/32) * 250;
+ break;
+
+ case LM70_CHIP_TMP121:
+ raw = (rxbuf[0] << 8) + rxbuf[1];
+ val = (raw / 8) * 625 / 10;
+ break;
+ }
+ dev_dbg(dev, "raw=0x%x\n", raw);
status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
out:
mutex_unlock(&p_lm70->lock);
@@ -93,27 +110,37 @@ static DEVICE_ATTR(temp1_input, S_IRUGO, lm70_sense_temp, NULL);
static ssize_t lm70_show_name(struct device *dev, struct device_attribute
*devattr, char *buf)
{
- return sprintf(buf, "lm70\n");
+ struct lm70 *p_lm70 = dev_get_drvdata(dev);
+ int ret;
+
+ switch (p_lm70->chip) {
+ case LM70_CHIP_LM70:
+ ret = sprintf(buf, "lm70\n");
+ break;
+ case LM70_CHIP_TMP121:
+ ret = sprintf(buf, "tmp121\n");
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ return ret;
}
static DEVICE_ATTR(name, S_IRUGO, lm70_show_name, NULL);
/*----------------------------------------------------------------------*/
-static int __devinit lm70_probe(struct spi_device *spi)
+static int __devinit common_probe(struct spi_device *spi, int chip)
{
struct lm70 *p_lm70;
int status;
- /* signaling is SPI_MODE_0 on a 3-wire link (shared SI/SO) */
- if ((spi->mode & (SPI_CPOL|SPI_CPHA)) || !(spi->mode & SPI_3WIRE))
- return -EINVAL;
-
p_lm70 = kzalloc(sizeof *p_lm70, GFP_KERNEL);
if (!p_lm70)
return -ENOMEM;
mutex_init(&p_lm70->lock);
+ p_lm70->chip = chip;
/* sysfs hook */
p_lm70->hwmon_dev = hwmon_device_register(&spi->dev);
@@ -141,6 +168,20 @@ out_dev_reg_failed:
return status;
}
+static int __devinit lm70_probe(struct spi_device *spi)
+{
+ /* signaling is SPI_MODE_0 on a 3-wire link (shared SI/SO) */
+ if ((spi->mode & (SPI_CPOL|SPI_CPHA)) || !(spi->mode & SPI_3WIRE))
+ return -EINVAL;
+
+ return common_probe(spi, LM70_CHIP_LM70);
+}
+
+static int __devinit tmp121_probe(struct spi_device *spi)
+{
+ return common_probe(spi, LM70_CHIP_TMP121);
+}
+
static int __devexit lm70_remove(struct spi_device *spi)
{
struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev);
@@ -154,6 +195,15 @@ static int __devexit lm70_remove(struct spi_device *spi)
return 0;
}
+static struct spi_driver tmp121_driver = {
+ .driver = {
+ .name = "tmp121",
+ .owner = THIS_MODULE,
+ },
+ .probe = tmp121_probe,
+ .remove = __devexit_p(lm70_remove),
+};
+
static struct spi_driver lm70_driver = {
.driver = {
.name = "lm70",
@@ -165,17 +215,26 @@ static struct spi_driver lm70_driver = {
static int __init init_lm70(void)
{
- return spi_register_driver(&lm70_driver);
+ int ret = spi_register_driver(&lm70_driver);
+ if (ret)
+ return ret;
+
+ ret = spi_register_driver(&tmp121_driver);
+ if (ret)
+ spi_unregister_driver(&lm70_driver);
+
+ return ret;
}
static void __exit cleanup_lm70(void)
{
spi_unregister_driver(&lm70_driver);
+ spi_unregister_driver(&tmp121_driver);
}
module_init(init_lm70);
module_exit(cleanup_lm70);
MODULE_AUTHOR("Kaiwan N Billimoria");
-MODULE_DESCRIPTION("National Semiconductor LM70 Linux driver");
+MODULE_DESCRIPTION("National Semiconductor LM70 / TI TMP121 Linux driver");
MODULE_LICENSE("GPL");
--
1.6.0.2
