The mcp3021 scaling code is dividing the VDD (full-scale) value in
millivolts by the A2D resolution to obtain the scaling factor. When VDD
is 3300mV (the standard value) and the resolution is 12-bit (4096
divisions), the result is a scale factor of 3300/4096, which is always
one. Effectively, the raw A2D reading is always being returned because
no scaling is applied.
This patch fixes the issue and simplifies the register-to-volts
calculation, removing the unneeded "output_scale" struct member.
Signed-off-by: Nick Stevens <Nick.Stevens@digi.com>
Cc: stable@vger.kernel.org # v3.10+
[Guenter Roeck: Dropped unnecessary value check]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This Patch adds support for mcp3221 chip to the
mcp3021 driver.
Signed-off-by: Sven Schuchmann <schuchmann@schleissheimer.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This Patch is to prepare the MCP3021 driver to support
other chips like the MCP3221. The hard defined chip data
is now stored within the data struct of each chip.
Signed-off-by: Sven Schuchmann <schuchmann@schleissheimer.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Convert to use devm_ functions to reduce code size and simplify the code.
Cc: Mingkai Hu <Mingkai.hu@freescale.com>
Cc: Xie Xiaobo <X.Xie@freescale.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add I2C driver for MCP3021 that is an ADC chip from Microchip.
The MCP3021 is a successive approximation A/D converter (ADC)
with 10-bit resolution.
The driver export the value of Vin to sysfs, the voltage unit is
mV. Through the sysfs interface, lm-sensors tool can also display
Vin voltage.
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Xie Xiaobo <X.Xie@freescale.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Stevens, Nick