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raw | patch | inline | side by side (parent: f2f68ec)
author | Lukas Wunner <lukas@wunner.de> | |
Tue, 22 Aug 2017 13:33:00 +0000 (15:33 +0200) | ||
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
Thu, 12 Oct 2017 09:27:34 +0000 (11:27 +0200) |
commit e6f4794371ee7cce1339e7ca9542f1e703c5f84a upstream.
Commit f686a36b4b79 ("iio: adc: mcp320x: Add support for mcp3301")
returns a signed voltage from mcp320x_adc_conversion() but neglects that
the caller interprets a negative return value as failure. Only mcp3301
(and the upcoming mcp3550/1/3) is affected as the other chips are
incapable of measuring negative voltages.
Fix and while at it, add mcp3301 to the list of supported chips at the
top of the file.
Fixes: f686a36b4b79 ("iio: adc: mcp320x: Add support for mcp3301")
Cc: Andrea Galbusera <gizero@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f686a36b4b79 ("iio: adc: mcp320x: Add support for mcp3301")
returns a signed voltage from mcp320x_adc_conversion() but neglects that
the caller interprets a negative return value as failure. Only mcp3301
(and the upcoming mcp3550/1/3) is affected as the other chips are
incapable of measuring negative voltages.
Fix and while at it, add mcp3301 to the list of supported chips at the
top of the file.
Fixes: f686a36b4b79 ("iio: adc: mcp320x: Add support for mcp3301")
Cc: Andrea Galbusera <gizero@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/iio/adc/mcp320x.c | patch | blob | history |
index 8569c8e1f4b276db3e968356626c67fab9b60c16..5c51f6f5cbffb58b0baae073f16b088a0e077e37 100644 (file)
* MCP3204
* MCP3208
* ------------
+ * 13 bit converter
+ * MCP3301
*
* Datasheet can be found here:
* http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf mcp3001
}
static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
- bool differential, int device_index)
+ bool differential, int device_index, int *val)
{
int ret;
switch (device_index) {
case mcp3001:
- return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+ *val = (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+ return 0;
case mcp3002:
case mcp3004:
case mcp3008:
- return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+ *val = (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+ return 0;
case mcp3201:
- return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+ *val = (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+ return 0;
case mcp3202:
case mcp3204:
case mcp3208:
- return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+ *val = (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+ return 0;
case mcp3301:
- return sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12);
+ *val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8
+ | adc->rx_buf[1], 12);
+ return 0;
default:
return -EINVAL;
}
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = mcp320x_adc_conversion(adc, channel->address,
- channel->differential, device_index);
-
+ channel->differential, device_index, val);
if (ret < 0)
goto out;
- *val = ret;
ret = IIO_VAL_INT;
break;