[PATCH 2/2] iio: adc: ti-adc128s052: Add lower resolution devices support

Nishanth Menon
2022-07-01T04:29:52Z

The adcxx4s communicates with a host processor via an SPI/Microwire Bus
interface. The device family responds with 12bit data, of which the LSB
bits are transmitted by the lower resolution devices as 0. We don't need
to mess with ADC108S102_BITS as a result for the lower resolution
devices.

I have been able to test adc102s051, hence adding just the missing
ones in that family.

Lets reuse the driver to support the family of devices with name
ADC<bb><c>S<sss>, where
* bb is the resolution in number of bits (8, 10, 12)
* c is the number of channels (1, 2, 4, 8)
* sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
and 101 for 1 MSPS)

Complete datasheets are available at TI's website here:
https://www.ti.com/lit/gpn/adc<bb><c>s<sss>.pdf

Also see: drivers/hwmon/adcxx.c

Signed-off-by: Nishanth Menon <nm@ti.com>
---

This does add on additional sparse warnings around casting .data value
to const from int for the of_match_table, and a bunch around the .cls
field for acpi_device_id - maybe someone could suggest a smarter way to
fix those.

Applies after https://lore.kernel.org/linux-iio/20220630230107.13438-1-nm@ti.com/

drivers/iio/adc/ti-adc128s052.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/iio/adc/ti-adc128s052.c b/drivers/iio/adc/ti-adc128s052.c
index 21a7764cbb93..0a3aab4df60e 100644
--- a/drivers/iio/adc/ti-adc128s052.c
+++ b/drivers/iio/adc/ti-adc128s052.c
@@ -7,6 +7,20 @@
* https://www.ti.com/lit/ds/symlink/adc128s052.pdf
* https://www.ti.com/lit/ds/symlink/adc122s021.pdf
* https://www.ti.com/lit/ds/symlink/adc124s021.pdf
+ *
+ * The adcxx4s communicates with a host processor via an SPI/Microwire Bus
+ * interface. This driver supports the whole family of devices with name
+ * ADC<bb><c>S<sss>, where
+ * bb is the resolution in number of bits (8, 10, 12)
+ * c is the number of channels (1, 2, 4, 8)
+ * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
+ * and 101 for 1 MSPS)
+ *
+ * Complete datasheets are available at TI's website here:
+ * https://www.ti.com/lit/gpn/adc<bb><c>s<sss>.pdf
+ *
+ * Handling of 8, 10 and 12 bits converters are the same, the
+ * unavailable bits are 0 in LSB :)
*/

#include <linux/acpi.h>
@@ -185,6 +199,12 @@ static const struct of_device_id adc128_of_match[] = {
{ .compatible = "ti,adc122s021", .data = 1},
{ .compatible = "ti,adc122s051", .data = 1},
{ .compatible = "ti,adc122s101", .data = 1},
+ { .compatible = "ti,adc102s021", .data = 1},
+ { .compatible = "ti,adc102s051", .data = 1},
+ { .compatible = "ti,adc102s101", .data = 1},
+ { .compatible = "ti,adc082s021", .data = 1},
+ { .compatible = "ti,adc082s051", .data = 1},
+ { .compatible = "ti,adc082s101", .data = 1},
{ .compatible = "ti,adc124s021", .data = 2},
{ .compatible = "ti,adc124s051", .data = 2},
{ .compatible = "ti,adc124s101", .data = 2},
@@ -197,6 +217,12 @@ static const struct spi_device_id adc128_id[] = {
{ "adc122s021", 1 },
{ "adc122s051", 1 },
{ "adc122s101", 1 },
+ { "adc102s021", 1 },
+ { "adc102s051", 1 },
+ { "adc102s101", 1 },
+ { "adc082s021", 1 },
+ { "adc082s051", 1 },
+ { "adc082s101", 1 },
{ "adc124s021", 2 },
{ "adc124s051", 2 },
{ "adc124s101", 2 },
--
2.31.1