All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v3 3/3] hwmon: (pmbus/ltc2978) Set voltage resolution
@ 2022-06-14  9:51 Mårten Lindahl
  2022-06-20 15:16 ` Guenter Roeck
  0 siblings, 1 reply; 3+ messages in thread
From: Mårten Lindahl @ 2022-06-14  9:51 UTC (permalink / raw)
  To: Guenter Roeck, Jean Delvare; +Cc: linux-hwmon, kernel, Mårten Lindahl

The LTC2977 regulator does not set the regulator_desc .n_voltages value
which is needed in order to let the regulator core list the regulator
voltage range.

This patch defines a regulator_desc with a voltage range, and uses it
for defining voltage resolution for regulators LTC2972/LTC2974/LTC2975/
LTC2977/LTC2978/LTC2979/LTC2980/LTM2987 based on that they all have a 16
bit ADC with the same stepwise 122.07uV resolution. It also scales the
resolution to a 1mV resolution which is easier to handle.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
---
 drivers/hwmon/pmbus/ltc2978.c | 44 +++++++++++++++++++++++++++++++----
 drivers/hwmon/pmbus/pmbus.h   |  8 +++++--
 2 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index 531aa674a928..6d2592731ba3 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -562,7 +562,24 @@ static const struct i2c_device_id ltc2978_id[] = {
 MODULE_DEVICE_TABLE(i2c, ltc2978_id);
 
 #if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+#define LTC2978_ADC_RES	0xFFFF
+#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)
+
 static const struct regulator_desc ltc2978_reg_desc[] = {
+	PMBUS_REGULATOR_STEP("vout", 0, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 1, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 2, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 3, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 4, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 5, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 6, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+	PMBUS_REGULATOR_STEP("vout", 7, LTC2978_N_VOLTAGES, LTC2978_UV_STEP),
+};
+
+static const struct regulator_desc ltc2978_reg_desc_default[] = {
 	PMBUS_REGULATOR("vout", 0),
 	PMBUS_REGULATOR("vout", 1),
 	PMBUS_REGULATOR("vout", 2),
@@ -839,10 +856,29 @@ static int ltc2978_probe(struct i2c_client *client)
 
 #if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
 	info->num_regulators = info->pages;
-	info->reg_desc = ltc2978_reg_desc;
-	if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
-		dev_err(&client->dev, "num_regulators too large!");
-		info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
+	switch (data->id) {
+	case ltc2972:
+	case ltc2974:
+	case ltc2975:
+	case ltc2977:
+	case ltc2978:
+	case ltc2979:
+	case ltc2980:
+	case ltm2987:
+		info->reg_desc = ltc2978_reg_desc;
+		if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
+			dev_warn(&client->dev, "num_regulators too large!");
+			info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
+		}
+		break;
+	default:
+		info->reg_desc = ltc2978_reg_desc_default;
+		if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc_default)) {
+			dev_warn(&client->dev, "num_regulators too large!");
+			info->num_regulators =
+			    ARRAY_SIZE(ltc2978_reg_desc_default);
+		}
+		break;
 	}
 #endif
 
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index c031a9700ace..4a4689c4ab7f 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -463,8 +463,8 @@ struct pmbus_driver_info {
 
 extern const struct regulator_ops pmbus_regulator_ops;
 
-/* Macro for filling in array of struct regulator_desc */
-#define PMBUS_REGULATOR(_name, _id)				\
+/* Macros for filling in array of struct regulator_desc */
+#define PMBUS_REGULATOR_STEP(_name, _id, _voltages, _step)  \
 	[_id] = {						\
 		.name = (_name # _id),				\
 		.supply_name = "vin",				\
@@ -474,8 +474,12 @@ extern const struct regulator_ops pmbus_regulator_ops;
 		.ops = &pmbus_regulator_ops,			\
 		.type = REGULATOR_VOLTAGE,			\
 		.owner = THIS_MODULE,				\
+		.n_voltages = _voltages,			\
+		.uV_step = _step,				\
 	}
 
+#define PMBUS_REGULATOR(_name, _id)	PMBUS_REGULATOR_STEP(_name, _id, 0, 0)
+
 /* Function declarations */
 
 void pmbus_clear_cache(struct i2c_client *client);
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* [PATCH v3 0/3] hwmon: (pmbus/ltc2978) Set voltage resolution
@ 2022-06-14  9:38 Mårten Lindahl
  2022-06-14  9:38 ` [PATCH v3 3/3] " Mårten Lindahl
  0 siblings, 1 reply; 3+ messages in thread
From: Mårten Lindahl @ 2022-06-14  9:38 UTC (permalink / raw)
  To: Guenter Roeck, Jean Delvare; +Cc: linux-hwmon, kernel, Mårten Lindahl

Hi!

When checking if a regulator supports a voltage range, the regulator
needs to have support for listing the range or else -EINVAL will be
returned.

This support does not exist for the LTC2977 regulator, so this change
adds support for list voltage to the pmbus regulators by adding
regulator_list_voltage_linear to the pmbus_regulator_ops. It also
defines the voltage resolution for regulators LTC2972/LTC2974/LTC2975/
LTC2977/LTC2978/LTC2979/LTC2980/LTM2987 based on that they all have the
same stepwise 122.07uV resolution, and scales the resolution to a 1mV
resolution which is easier to handle.

These patches have been tested on an ARTPEC-8 developer board with a group
of LTC2977 power regulators.

Kind regards
Mårten Lindahl

Changes in v3:
 - Move read of low/high margins into local functions
 - Add check for invalid selector value
 - Introduce new macro PMBUS_REGULATOR_STEP(_name, _id, _voltages, _step)

Changes in v2:
 - Correct #define format
 - Change dev_err to dev_warn
 - Add new pmbus_regulator_list_voltage function
 - Cache low/high vout margins

Mårten Lindahl (3):
  hwmon: (pmbus) Introduce and use cached vout margins
  hwmon: (pmbus) Add list_voltage to pmbus ops
  hwmon: (pmbus/ltc2978) Set voltage resolution

 drivers/hwmon/pmbus/ltc2978.c    |  44 +++++++++++--
 drivers/hwmon/pmbus/pmbus.h      |   8 ++-
 drivers/hwmon/pmbus/pmbus_core.c | 108 ++++++++++++++++++++++++++-----
 3 files changed, 137 insertions(+), 23 deletions(-)

-- 
2.30.2


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-06-20 15:22 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-14  9:51 [PATCH v3 3/3] hwmon: (pmbus/ltc2978) Set voltage resolution Mårten Lindahl
2022-06-20 15:16 ` Guenter Roeck
  -- strict thread matches above, loose matches on Subject: below --
2022-06-14  9:38 [PATCH v3 0/3] " Mårten Lindahl
2022-06-14  9:38 ` [PATCH v3 3/3] " Mårten Lindahl

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.