From: Jerome Brunet Date: Mon, 2 Dec 2024 10:28:00 +0000 (+0100) Subject: hwmon: (pmbus/core) improve handling of write protected regulators X-Git-Tag: v6.14-rc1~154^2~35 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f40452577557caf0e5d0ff182da8479c3d492ac5;p=thirdparty%2Fkernel%2Flinux.git hwmon: (pmbus/core) improve handling of write protected regulators Writing PMBus protected registers does succeed from the smbus perspective, even if the write is ignored by the device and a communication fault is raised. This fault will silently be caught and cleared by pmbus irq if one has been registered. This means that the regulator call may return succeed although the operation was ignored. With this change, the operation which are not supported will be properly flagged as such and the regulator framework won't even try to execute them. Signed-off-by: Jerome Brunet [groeck: Adjust to EXPORT_SYMBOL_NS_GPL API change] Signed-off-by: Guenter Roeck --- diff --git a/Documentation/hwmon/pmbus-core.rst b/Documentation/hwmon/pmbus-core.rst index 686a00265bf71..0a251960f8910 100644 --- a/Documentation/hwmon/pmbus-core.rst +++ b/Documentation/hwmon/pmbus-core.rst @@ -312,6 +312,10 @@ currently provides a flags field with four bits used:: #define PMBUS_USE_COEFFICIENTS_CMD BIT(5) + #define PMBUS_OP_PROTECTED BIT(6) + + #define PMBUS_VOUT_PROTECTED BIT(7) + struct pmbus_platform_data { u32 flags; /* Device specific flags */ @@ -373,3 +377,13 @@ PMBUS_USE_COEFFICIENTS_CMD When this flag is set the PMBus core driver will use the COEFFICIENTS register to initialize the coefficients for the direct mode format. + +PMBUS_OP_PROTECTED + +Set if the chip OPERATION command is protected and protection is not +determined by the standard WRITE_PROTECT command. + +PMBUS_VOUT_PROTECTED + +Set if the chip VOUT_COMMAND command is protected and protection is not +determined by the standard WRITE_PROTECT command. diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h index d605412a3173b..ddb19c9726d62 100644 --- a/drivers/hwmon/pmbus/pmbus.h +++ b/drivers/hwmon/pmbus/pmbus.h @@ -487,6 +487,8 @@ struct pmbus_driver_info { /* Regulator ops */ extern const struct regulator_ops pmbus_regulator_ops; +int pmbus_regulator_init_cb(struct regulator_dev *rdev, + struct regulator_config *config); /* Macros for filling in array of struct regulator_desc */ #define PMBUS_REGULATOR_STEP(_name, _id, _voltages, _step, _min_uV) \ @@ -501,6 +503,7 @@ extern const struct regulator_ops pmbus_regulator_ops; .n_voltages = _voltages, \ .uV_step = _step, \ .min_uV = _min_uV, \ + .init_cb = pmbus_regulator_init_cb, \ } #define PMBUS_REGULATOR(_name, _id) PMBUS_REGULATOR_STEP(_name, _id, 0, 0, 0) @@ -516,6 +519,7 @@ extern const struct regulator_ops pmbus_regulator_ops; .n_voltages = _voltages, \ .uV_step = _step, \ .min_uV = _min_uV, \ + .init_cb = pmbus_regulator_init_cb, \ } #define PMBUS_REGULATOR_ONE(_name) PMBUS_REGULATOR_STEP_ONE(_name, 0, 0, 0) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index a1375cb6b648c..5976dd819b3c6 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -2665,6 +2665,30 @@ static void pmbus_remove_pec(void *dev) device_remove_file(dev, &dev_attr_pec); } +static void pmbus_init_wp(struct i2c_client *client, struct pmbus_data *data) +{ + int ret; + + ret = _pmbus_read_byte_data(client, -1, PMBUS_WRITE_PROTECT); + if (ret < 0) + return; + + switch (ret & PB_WP_ANY) { + case PB_WP_ALL: + data->flags |= PMBUS_OP_PROTECTED; + fallthrough; + case PB_WP_OP: + data->flags |= PMBUS_VOUT_PROTECTED; + fallthrough; + case PB_WP_VOUT: + data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK; + break; + + default: + break; + } +} + static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data, struct pmbus_driver_info *info) { @@ -2718,12 +2742,8 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data, * faults, and we should not try it. Also, in that case, writes into * limit registers need to be disabled. */ - if (!(data->flags & PMBUS_NO_WRITE_PROTECT)) { - ret = _pmbus_read_byte_data(client, -1, PMBUS_WRITE_PROTECT); - - if (ret > 0 && (ret & PB_WP_ANY)) - data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK; - } + if (!(data->flags & PMBUS_NO_WRITE_PROTECT)) + pmbus_init_wp(client, data); ret = i2c_smbus_read_byte_data(client, PMBUS_REVISION); if (ret >= 0) @@ -3183,8 +3203,12 @@ static int pmbus_regulator_list_voltage(struct regulator_dev *rdev, { struct device *dev = rdev_get_dev(rdev); struct i2c_client *client = to_i2c_client(dev->parent); + struct pmbus_data *data = i2c_get_clientdata(client); int val, low, high; + if (data->flags & PMBUS_VOUT_PROTECTED) + return 0; + if (selector >= rdev->desc->n_voltages || selector < rdev->desc->linear_min_sel) return -EINVAL; @@ -3219,6 +3243,22 @@ const struct regulator_ops pmbus_regulator_ops = { }; EXPORT_SYMBOL_NS_GPL(pmbus_regulator_ops, "PMBUS"); +int pmbus_regulator_init_cb(struct regulator_dev *rdev, + struct regulator_config *config) +{ + struct pmbus_data *data = config->driver_data; + struct regulation_constraints *constraints = rdev->constraints; + + if (data->flags & PMBUS_OP_PROTECTED) + constraints->valid_ops_mask &= ~REGULATOR_CHANGE_STATUS; + + if (data->flags & PMBUS_VOUT_PROTECTED) + constraints->valid_ops_mask &= ~REGULATOR_CHANGE_VOLTAGE; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(pmbus_regulator_init_cb, "PMBUS"); + static int pmbus_regulator_register(struct pmbus_data *data) { struct device *dev = data->dev; diff --git a/include/linux/pmbus.h b/include/linux/pmbus.h index fa9f08164c365..884040e1383bf 100644 --- a/include/linux/pmbus.h +++ b/include/linux/pmbus.h @@ -73,6 +73,20 @@ */ #define PMBUS_USE_COEFFICIENTS_CMD BIT(5) +/* + * PMBUS_OP_PROTECTED + * Set if the chip OPERATION command is protected and protection is not + * determined by the standard WRITE_PROTECT command. + */ +#define PMBUS_OP_PROTECTED BIT(6) + +/* + * PMBUS_VOUT_PROTECTED + * Set if the chip VOUT_COMMAND command is protected and protection is not + * determined by the standard WRITE_PROTECT command. + */ +#define PMBUS_VOUT_PROTECTED BIT(7) + struct pmbus_platform_data { u32 flags; /* Device specific flags */