On 10/26/24 02:08, Patryk Biel wrote:
LTC2971 is a power manager similar to already supported LTC2972,
it uses the same register set but supports a different voltage range.
Signed-off-by: Patryk Biel <pbiel7@xxxxxxxxx>
---
drivers/hwmon/pmbus/ltc2978.c | 34 +++++++++++++++++++++++++++++++---
Please also update Documentation/hwmon/ltc2978.rst and drivers/hwmon/pmbus/Kconfig.
1 file changed, 31 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index 73a86f4d647288be97615f19a5c6314e4036e6a3..681e7b811dbcc263fe8f5e4f9da30fcbc7e019ad 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -21,7 +21,8 @@
enum chips {
/* Managers */
- ltc2972, ltc2974, ltc2975, ltc2977, ltc2978, ltc2979, ltc2980,
+ ltc2971, ltc2972, ltc2974, ltc2975, ltc2977, ltc2978,
+ ltc2979, ltc2980,
/* Controllers */
ltc3880, ltc3882, ltc3883, ltc3884, ltc3886, ltc3887, ltc3889, ltc7132, ltc7880,
/* Modules */
@@ -61,6 +62,7 @@ enum chips {
#define LTC2978_ID_MASK 0xfff0
+#define LTC2971_ID 0x0320
#define LTC2972_ID 0x0310
#define LTC2974_ID 0x0210
#define LTC2975_ID 0x0220
@@ -533,6 +535,7 @@ static int ltc2978_write_word_data(struct i2c_client *client, int page,
}
static const struct i2c_device_id ltc2978_id[] = {
+ {"ltc2971", ltc2971},
{"ltc2972", ltc2972},
{"ltc2974", ltc2974},
{"ltc2975", ltc2975},
@@ -564,11 +567,19 @@ MODULE_DEVICE_TABLE(i2c, ltc2978_id);
#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
#define LTC2978_ADC_RES 0xFFFF
+#define LTC2978_UV_STEP 1000
+
+/* Common for most chips */
#define LTC2978_N_ADC 122
#define LTC2978_MAX_UV (LTC2978_ADC_RES * LTC2978_N_ADC)
-#define LTC2978_UV_STEP 1000
#define LTC2978_N_VOLTAGES ((LTC2978_MAX_UV / LTC2978_UV_STEP) + 1)
Please just add the chip specific defines as you do below, and don't move
the defines above around. It happens a lot that there are common definitions
followed by chip specific ones. Spelling that out explicitly doesn't really
add much if any value and just results in rearranged code whenever a new
chip with other parameters is added.
+/* LTC2971 */
+#define LTC2971_N_ADC 4500
+#define LTC2971_MAX_UV (LTC2978_ADC_RES * LTC2971_N_ADC)
I think something is wrong here.
4500 * 65535 uV ~= 295V.
However, the datasheet says that the output voltage is calculated by
(register value / 1024), where the register value is a 16-bit value.
65535 / 1024 ~= 64V. Where does the 4,500 come from ?
+#define LTC2971_N_VOLTAGES ((LTC2971_MAX_UV / LTC2978_UV_STEP) + 1)
Does the chip really support 294,908 voltages ? That seems impossible since
the VOUT_COMMAND register is only 16 bit wide.
Unless I misunderstand the datasheet, the voltage resolution should be 1/1024V
or 976 uV, and there should be 65,536 voltages. This is from the chip datasheet,
PMBus Command Description, Note 1: Data Formats, for L16 data.
If my understanding is wrong, please explain and document your numbers.
Thanks,
Guenter
