| Message ID | 20230919054824.3368656-1-naresh.solanki@9elements.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v4] regulator (max5970): Add hwmon support | expand |
On Tue, Sep 19, 2023 at 07:48:23AM +0200, Naresh Solanki wrote: > Utilize the integrated 10-bit ADC in Max5970/Max5978 to enable voltage > and current monitoring. This feature is seamlessly integrated through > the hwmon subsystem. Guenter, are you OK with the hwmon side of this?
On Tue, Sep 19, 2023 at 07:48:23AM +0200, Naresh Solanki wrote: > Utilize the integrated 10-bit ADC in Max5970/Max5978 to enable voltage > and current monitoring. This feature is seamlessly integrated through > the hwmon subsystem. > > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> > --- > Changes in V4: > - Use IS_REACHABLE > - Use rdevs array for hwmon ops. > - Remove duplicate i2c_set_clientdata > Changes in V3: > - Update signed-off > - Add break > - Update hwmon dev register name to max5970 > - Remove changes in Kconfig. > Changes in V2: > - default case added for switch statement > - Add dependency on HWMON > --- > drivers/regulator/max5970-regulator.c | 138 +++++++++++++++++++++++++- > 1 file changed, 136 insertions(+), 2 deletions(-) > > > base-commit: 41f02a383ac652f1a0b5538c5901b7ec93e37290 > > diff --git a/drivers/regulator/max5970-regulator.c b/drivers/regulator/max5970-regulator.c > index b56a174cde3d..06168fe1dadd 100644 > --- a/drivers/regulator/max5970-regulator.c > +++ b/drivers/regulator/max5970-regulator.c > @@ -10,6 +10,7 @@ > #include <linux/bitops.h> > #include <linux/device.h> > #include <linux/err.h> > +#include <linux/hwmon.h> > #include <linux/module.h> > #include <linux/io.h> > #include <linux/of.h> > @@ -32,6 +33,128 @@ enum max597x_regulator_id { > MAX597X_SW1, > }; > > +static int max5970_read_adc(struct regmap *regmap, int reg, long *val) > +{ > + u8 reg_data[2]; > + int ret; > + > + ret = regmap_bulk_read(regmap, reg, ®_data[0], 2); > + if (ret < 0) > + return ret; > + > + *val = (reg_data[0] << 2) | (reg_data[1] & 3); > + > + return 0; > +} > + > +static int max5970_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct regulator_dev **rdevs = dev_get_drvdata(dev); > + struct max5970_regulator *ddata = rdev_get_drvdata(rdevs[channel]); > + struct regmap *regmap = ddata->regmap; > + int ret; > + > + switch (type) { > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + ret = max5970_read_adc(regmap, MAX5970_REG_CURRENT_H(channel), val); > + /* > + * Calculate current from ADC value, IRNG range & shunt resistor value. > + * ddata->irng holds the voltage corresponding to the maximum value the > + * 10-bit ADC can measure. > + * To obtain the output, multiply the ADC value by the IRNG range (in > + * millivolts) and then divide it by the maximum value of the 10-bit ADC. > + */ > + *val = (*val * ddata->irng) >> 10; > + /* Convert the voltage meansurement across shunt resistor to current */ > + *val = (*val * 1000) / ddata->shunt_micro_ohms; > + return ret; > + default: > + return -EOPNOTSUPP; > + } > + > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + ret = max5970_read_adc(regmap, MAX5970_REG_VOLTAGE_H(channel), val); > + /* > + * Calculate voltage from ADC value and MON range. > + * ddata->mon_rng holds the voltage corresponding to the maximum value the > + * 10-bit ADC can measure. > + * To obtain the output, multiply the ADC value by the MON range (in > + * microvolts) and then divide it by the maximum value of the 10-bit ADC. > + */ > + *val = mul_u64_u32_shr(*val, ddata->mon_rng, 10); > + /* uV to mV */ > + *val = *val / 1000; > + return ret; > + default: > + return -EOPNOTSUPP; > + } > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static umode_t max5970_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + struct regulator_dev **rdevs = (struct regulator_dev **)data; > + struct max5970_regulator *ddata; > + > + if (!rdevs || !rdevs[channel]) How can rdevs be NULL here ? Unless I am missing something, that can only happen if its allocation in the probe function failed, but then the system would long since have crashed before it gets here. Also, rdevs[] only has as many entries as there are switches. That can be 1 or 2. However, the hwmon subsystem will always assume that there are two channels, because it is told so, and it will thus try to access rdevs[1] even if only a single channel was allocated. > + return 0; > + > + ddata = rdev_get_drvdata(rdevs[channel]); With the above in mind, I wonder what that points to if channel == 1 and ddata->num_switches == 1. > + > + if (!ddata || channel >= ddata->num_switches) > + return 0; > + > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + return 0444; > + default: > + break; > + } > + break; > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + /* Current measurement requires knowledge of the shunt resistor value. */ > + if (ddata->shunt_micro_ohms) > + return 0444; > + break; > + default: > + break; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_ops max5970_hwmon_ops = { > + .is_visible = max5970_is_visible, > + .read = max5970_read, > +}; > + > +static const struct hwmon_channel_info *max5970_info[] = { > + HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT), > + HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT, HWMON_C_INPUT), > + NULL > +}; > + > +static const struct hwmon_chip_info max5970_chip_info = { > + .ops = &max5970_hwmon_ops, > + .info = max5970_info, > +}; > + > static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity) > { > int ret, reg; > @@ -431,7 +554,8 @@ static int max597x_regulator_probe(struct platform_device *pdev) > struct i2c_client *i2c = to_i2c_client(pdev->dev.parent); > struct regulator_config config = { }; > struct regulator_dev *rdev; > - struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES]; > + struct regulator_dev **rdevs = NULL; > + struct device *hwmon_dev; > int num_switches; > int ret, i; > > @@ -451,9 +575,10 @@ static int max597x_regulator_probe(struct platform_device *pdev) > else > return -ENODEV; > > - i2c_set_clientdata(i2c, max597x); > num_switches = max597x->num_switches; > > + rdevs = devm_kcalloc(&i2c->dev, num_switches, sizeof(struct regulator_dev *), GFP_KERNEL); > + What if devm_kcalloc() returns NULL ? > for (i = 0; i < num_switches; i++) { > data = > devm_kzalloc(&i2c->dev, sizeof(struct max5970_regulator), > @@ -485,6 +610,15 @@ static int max597x_regulator_probe(struct platform_device *pdev) > max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms; > } > > + if (IS_REACHABLE(CONFIG_HWMON)) { > + hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970", rdevs, > + &max5970_chip_info, NULL); > + if (IS_ERR(hwmon_dev)) { > + return dev_err_probe(&i2c->dev, PTR_ERR(hwmon_dev), > + "Unable to register hwmon device\n"); > + } > + } > + > if (i2c->irq) { > ret = > max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches,
On Tue, Sep 26, 2023 at 05:28:15PM +0200, Mark Brown wrote: > On Tue, Sep 19, 2023 at 07:48:23AM +0200, Naresh Solanki wrote: > > Utilize the integrated 10-bit ADC in Max5970/Max5978 to enable voltage > > and current monitoring. This feature is seamlessly integrated through > > the hwmon subsystem. > > Guenter, are you OK with the hwmon side of this? Sorry, I lost track. Not really; see my response to the patch. I think the memory allocation in that driver is a bit too complicated. It trades simplicity for minor memory savings, and even those savings are questionable. It would have been much easier and simpler to just add a two-element regulator_dev array to struct max5970_regulator and live with the "lost" memory if only one of them is used. I suspect that would have consumed less memory and code overall. Guenter
Hi Guenter, On Wed, 27 Sept 2023 at 01:06, Guenter Roeck <linux@roeck-us.net> wrote: > > On Tue, Sep 19, 2023 at 07:48:23AM +0200, Naresh Solanki wrote: > > Utilize the integrated 10-bit ADC in Max5970/Max5978 to enable voltage > > and current monitoring. This feature is seamlessly integrated through > > the hwmon subsystem. > > > > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> > > --- > > Changes in V4: > > - Use IS_REACHABLE > > - Use rdevs array for hwmon ops. > > - Remove duplicate i2c_set_clientdata > > Changes in V3: > > - Update signed-off > > - Add break > > - Update hwmon dev register name to max5970 > > - Remove changes in Kconfig. > > Changes in V2: > > - default case added for switch statement > > - Add dependency on HWMON > > --- > > drivers/regulator/max5970-regulator.c | 138 +++++++++++++++++++++++++- > > 1 file changed, 136 insertions(+), 2 deletions(-) > > > > > > base-commit: 41f02a383ac652f1a0b5538c5901b7ec93e37290 > > > > diff --git a/drivers/regulator/max5970-regulator.c b/drivers/regulator/max5970-regulator.c > > index b56a174cde3d..06168fe1dadd 100644 > > --- a/drivers/regulator/max5970-regulator.c > > +++ b/drivers/regulator/max5970-regulator.c > > @@ -10,6 +10,7 @@ > > #include <linux/bitops.h> > > #include <linux/device.h> > > #include <linux/err.h> > > +#include <linux/hwmon.h> > > #include <linux/module.h> > > #include <linux/io.h> > > #include <linux/of.h> > > @@ -32,6 +33,128 @@ enum max597x_regulator_id { > > MAX597X_SW1, > > }; > > > > +static int max5970_read_adc(struct regmap *regmap, int reg, long *val) > > +{ > > + u8 reg_data[2]; > > + int ret; > > + > > + ret = regmap_bulk_read(regmap, reg, ®_data[0], 2); > > + if (ret < 0) > > + return ret; > > + > > + *val = (reg_data[0] << 2) | (reg_data[1] & 3); > > + > > + return 0; > > +} > > + > > +static int max5970_read(struct device *dev, enum hwmon_sensor_types type, > > + u32 attr, int channel, long *val) > > +{ > > + struct regulator_dev **rdevs = dev_get_drvdata(dev); > > + struct max5970_regulator *ddata = rdev_get_drvdata(rdevs[channel]); > > + struct regmap *regmap = ddata->regmap; > > + int ret; > > + > > + switch (type) { > > + case hwmon_curr: > > + switch (attr) { > > + case hwmon_curr_input: > > + ret = max5970_read_adc(regmap, MAX5970_REG_CURRENT_H(channel), val); > > + /* > > + * Calculate current from ADC value, IRNG range & shunt resistor value. > > + * ddata->irng holds the voltage corresponding to the maximum value the > > + * 10-bit ADC can measure. > > + * To obtain the output, multiply the ADC value by the IRNG range (in > > + * millivolts) and then divide it by the maximum value of the 10-bit ADC. > > + */ > > + *val = (*val * ddata->irng) >> 10; > > + /* Convert the voltage meansurement across shunt resistor to current */ > > + *val = (*val * 1000) / ddata->shunt_micro_ohms; > > + return ret; > > + default: > > + return -EOPNOTSUPP; > > + } > > + > > + case hwmon_in: > > + switch (attr) { > > + case hwmon_in_input: > > + ret = max5970_read_adc(regmap, MAX5970_REG_VOLTAGE_H(channel), val); > > + /* > > + * Calculate voltage from ADC value and MON range. > > + * ddata->mon_rng holds the voltage corresponding to the maximum value the > > + * 10-bit ADC can measure. > > + * To obtain the output, multiply the ADC value by the MON range (in > > + * microvolts) and then divide it by the maximum value of the 10-bit ADC. > > + */ > > + *val = mul_u64_u32_shr(*val, ddata->mon_rng, 10); > > + /* uV to mV */ > > + *val = *val / 1000; > > + return ret; > > + default: > > + return -EOPNOTSUPP; > > + } > > + default: > > + return -EOPNOTSUPP; > > + } > > +} > > + > > +static umode_t max5970_is_visible(const void *data, > > + enum hwmon_sensor_types type, > > + u32 attr, int channel) > > +{ > > + struct regulator_dev **rdevs = (struct regulator_dev **)data; > > + struct max5970_regulator *ddata; > > + > > + if (!rdevs || !rdevs[channel]) > > How can rdevs be NULL here ? Unless I am missing something, that can > only happen if its allocation in the probe function failed, but then > the system would long since have crashed before it gets here. > > Also, rdevs[] only has as many entries as there are switches. That can > be 1 or 2. However, the hwmon subsystem will always assume that there are > two channels, because it is told so, and it will thus try to access rdevs[1] > even if only a single channel was allocated. Yes. Will update to: if (!rdevs[channel]) return 0; Also will simplify memory allocation to have two element array. > > > + return 0; > > + > > + ddata = rdev_get_drvdata(rdevs[channel]); > > With the above in mind, I wonder what that points to if channel == 1 and > ddata->num_switches == 1. This can be avoided with memory allocation simplification & previous if condition check. > > > + > > + if (!ddata || channel >= ddata->num_switches) > > + return 0; > > + > > + switch (type) { > > + case hwmon_in: > > + switch (attr) { > > + case hwmon_in_input: > > + return 0444; > > + default: > > + break; > > + } > > + break; > > + case hwmon_curr: > > + switch (attr) { > > + case hwmon_curr_input: > > + /* Current measurement requires knowledge of the shunt resistor value. */ > > + if (ddata->shunt_micro_ohms) > > + return 0444; > > + break; > > + default: > > + break; > > + } > > + break; > > + default: > > + break; > > + } > > + return 0; > > +} > > + > > +static const struct hwmon_ops max5970_hwmon_ops = { > > + .is_visible = max5970_is_visible, > > + .read = max5970_read, > > +}; > > + > > +static const struct hwmon_channel_info *max5970_info[] = { > > + HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT), > > + HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT, HWMON_C_INPUT), > > + NULL > > +}; > > + > > +static const struct hwmon_chip_info max5970_chip_info = { > > + .ops = &max5970_hwmon_ops, > > + .info = max5970_info, > > +}; > > + > > static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity) > > { > > int ret, reg; > > @@ -431,7 +554,8 @@ static int max597x_regulator_probe(struct platform_device *pdev) > > struct i2c_client *i2c = to_i2c_client(pdev->dev.parent); > > struct regulator_config config = { }; > > struct regulator_dev *rdev; > > - struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES]; > > + struct regulator_dev **rdevs = NULL; > > + struct device *hwmon_dev; > > int num_switches; > > int ret, i; > > > > @@ -451,9 +575,10 @@ static int max597x_regulator_probe(struct platform_device *pdev) > > else > > return -ENODEV; > > > > - i2c_set_clientdata(i2c, max597x); > > num_switches = max597x->num_switches; > > > > + rdevs = devm_kcalloc(&i2c->dev, num_switches, sizeof(struct regulator_dev *), GFP_KERNEL); > > + > > What if devm_kcalloc() returns NULL ? Will add error checking here. > > > for (i = 0; i < num_switches; i++) { > > data = > > devm_kzalloc(&i2c->dev, sizeof(struct max5970_regulator), > > @@ -485,6 +610,15 @@ static int max597x_regulator_probe(struct platform_device *pdev) > > max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms; > > } > > > > + if (IS_REACHABLE(CONFIG_HWMON)) { > > + hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970", rdevs, > > + &max5970_chip_info, NULL); > > + if (IS_ERR(hwmon_dev)) { > > + return dev_err_probe(&i2c->dev, PTR_ERR(hwmon_dev), > > + "Unable to register hwmon device\n"); > > + } > > + } > > + > > if (i2c->irq) { > > ret = > > max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches, Regards, Naresh
diff --git a/drivers/regulator/max5970-regulator.c b/drivers/regulator/max5970-regulator.c index b56a174cde3d..06168fe1dadd 100644 --- a/drivers/regulator/max5970-regulator.c +++ b/drivers/regulator/max5970-regulator.c @@ -10,6 +10,7 @@ #include <linux/bitops.h> #include <linux/device.h> #include <linux/err.h> +#include <linux/hwmon.h> #include <linux/module.h> #include <linux/io.h> #include <linux/of.h> @@ -32,6 +33,128 @@ enum max597x_regulator_id { MAX597X_SW1, }; +static int max5970_read_adc(struct regmap *regmap, int reg, long *val) +{ + u8 reg_data[2]; + int ret; + + ret = regmap_bulk_read(regmap, reg, ®_data[0], 2); + if (ret < 0) + return ret; + + *val = (reg_data[0] << 2) | (reg_data[1] & 3); + + return 0; +} + +static int max5970_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct regulator_dev **rdevs = dev_get_drvdata(dev); + struct max5970_regulator *ddata = rdev_get_drvdata(rdevs[channel]); + struct regmap *regmap = ddata->regmap; + int ret; + + switch (type) { + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + ret = max5970_read_adc(regmap, MAX5970_REG_CURRENT_H(channel), val); + /* + * Calculate current from ADC value, IRNG range & shunt resistor value. + * ddata->irng holds the voltage corresponding to the maximum value the + * 10-bit ADC can measure. + * To obtain the output, multiply the ADC value by the IRNG range (in + * millivolts) and then divide it by the maximum value of the 10-bit ADC. + */ + *val = (*val * ddata->irng) >> 10; + /* Convert the voltage meansurement across shunt resistor to current */ + *val = (*val * 1000) / ddata->shunt_micro_ohms; + return ret; + default: + return -EOPNOTSUPP; + } + + case hwmon_in: + switch (attr) { + case hwmon_in_input: + ret = max5970_read_adc(regmap, MAX5970_REG_VOLTAGE_H(channel), val); + /* + * Calculate voltage from ADC value and MON range. + * ddata->mon_rng holds the voltage corresponding to the maximum value the + * 10-bit ADC can measure. + * To obtain the output, multiply the ADC value by the MON range (in + * microvolts) and then divide it by the maximum value of the 10-bit ADC. + */ + *val = mul_u64_u32_shr(*val, ddata->mon_rng, 10); + /* uV to mV */ + *val = *val / 1000; + return ret; + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static umode_t max5970_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + struct regulator_dev **rdevs = (struct regulator_dev **)data; + struct max5970_regulator *ddata; + + if (!rdevs || !rdevs[channel]) + return 0; + + ddata = rdev_get_drvdata(rdevs[channel]); + + if (!ddata || channel >= ddata->num_switches) + return 0; + + switch (type) { + case hwmon_in: + switch (attr) { + case hwmon_in_input: + return 0444; + default: + break; + } + break; + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + /* Current measurement requires knowledge of the shunt resistor value. */ + if (ddata->shunt_micro_ohms) + return 0444; + break; + default: + break; + } + break; + default: + break; + } + return 0; +} + +static const struct hwmon_ops max5970_hwmon_ops = { + .is_visible = max5970_is_visible, + .read = max5970_read, +}; + +static const struct hwmon_channel_info *max5970_info[] = { + HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT), + HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT, HWMON_C_INPUT), + NULL +}; + +static const struct hwmon_chip_info max5970_chip_info = { + .ops = &max5970_hwmon_ops, + .info = max5970_info, +}; + static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity) { int ret, reg; @@ -431,7 +554,8 @@ static int max597x_regulator_probe(struct platform_device *pdev) struct i2c_client *i2c = to_i2c_client(pdev->dev.parent); struct regulator_config config = { }; struct regulator_dev *rdev; - struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES]; + struct regulator_dev **rdevs = NULL; + struct device *hwmon_dev; int num_switches; int ret, i; @@ -451,9 +575,10 @@ static int max597x_regulator_probe(struct platform_device *pdev) else return -ENODEV; - i2c_set_clientdata(i2c, max597x); num_switches = max597x->num_switches; + rdevs = devm_kcalloc(&i2c->dev, num_switches, sizeof(struct regulator_dev *), GFP_KERNEL); + for (i = 0; i < num_switches; i++) { data = devm_kzalloc(&i2c->dev, sizeof(struct max5970_regulator), @@ -485,6 +610,15 @@ static int max597x_regulator_probe(struct platform_device *pdev) max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms; } + if (IS_REACHABLE(CONFIG_HWMON)) { + hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970", rdevs, + &max5970_chip_info, NULL); + if (IS_ERR(hwmon_dev)) { + return dev_err_probe(&i2c->dev, PTR_ERR(hwmon_dev), + "Unable to register hwmon device\n"); + } + } + if (i2c->irq) { ret = max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches,
Utilize the integrated 10-bit ADC in Max5970/Max5978 to enable voltage and current monitoring. This feature is seamlessly integrated through the hwmon subsystem. Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> --- Changes in V4: - Use IS_REACHABLE - Use rdevs array for hwmon ops. - Remove duplicate i2c_set_clientdata Changes in V3: - Update signed-off - Add break - Update hwmon dev register name to max5970 - Remove changes in Kconfig. Changes in V2: - default case added for switch statement - Add dependency on HWMON --- drivers/regulator/max5970-regulator.c | 138 +++++++++++++++++++++++++- 1 file changed, 136 insertions(+), 2 deletions(-) base-commit: 41f02a383ac652f1a0b5538c5901b7ec93e37290