On Wed, May 29, 2019 at 5:40 AM Guenter Roeck <li...@roeck-us.net> wrote: > > On 5/29/19 12:11 AM, Andrey Smirnov wrote: > > Add code implementing HWMON adapter/compatibility layer to allow > > expositing various sensors present on power supply devices via HWMON > > subsystem. This is done in order to allow userspace to use single > > ABI/library(libsensors) to access/manipulate all of the sensors of the > > system. > > > > Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com> > > Cc: Chris Healy <cphe...@gmail.com> > > Cc: Lucas Stach <l.st...@pengutronix.de> > > Cc: Fabio Estevam <fabio.este...@nxp.com> > > Cc: Guenter Roeck <li...@roeck-us.net> > > Cc: Sebastian Reichel <s...@kernel.org> > > Cc: linux-kernel@vger.kernel.org > > Cc: linux...@vger.kernel.org > > --- > > drivers/power/supply/Kconfig | 14 + > > drivers/power/supply/Makefile | 1 + > > drivers/power/supply/power_supply_hwmon.c | 329 ++++++++++++++++++++++ > > include/linux/power_supply.h | 11 + > > 4 files changed, 355 insertions(+) > > create mode 100644 drivers/power/supply/power_supply_hwmon.c > > > > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig > > index 26dacdab03cc..1f2252cb95fd 100644 > > --- a/drivers/power/supply/Kconfig > > +++ b/drivers/power/supply/Kconfig > > @@ -14,6 +14,20 @@ config POWER_SUPPLY_DEBUG > > Say Y here to enable debugging messages for power supply class > > and drivers. > > > > +config POWER_SUPPLY_HWMON > > + bool > > + prompt "Expose power supply sensors as hwmon device" > > + depends on HWMON=y || HWMON=POWER_SUPPLY > > + default y > > Not sure if you want to enable that by default. >
That's what THERMAL_HWMON does which seems pretty analogous to this code. > > + help > > + This options enables API that allows sensors found on a > > + power supply device (current, voltage, temperature) to be > > + exposed as a hwmon device. > > + > > + Say 'Y' here if you want power supplies to > > + have hwmon sysfs interface too. > > + > > + > > config PDA_POWER > > tristate "Generic PDA/phone power driver" > > depends on !S390 > > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile > > index f208273f9686..c47e88ba16b9 100644 > > --- a/drivers/power/supply/Makefile > > +++ b/drivers/power/supply/Makefile > > @@ -6,6 +6,7 @@ power_supply-$(CONFIG_SYSFS) += > > power_supply_sysfs.o > > power_supply-$(CONFIG_LEDS_TRIGGERS) += power_supply_leds.o > > > > obj-$(CONFIG_POWER_SUPPLY) += power_supply.o > > +obj-$(CONFIG_POWER_SUPPLY_HWMON) += power_supply_hwmon.o > > obj-$(CONFIG_GENERIC_ADC_BATTERY) += generic-adc-battery.o > > > > obj-$(CONFIG_PDA_POWER) += pda_power.o > > diff --git a/drivers/power/supply/power_supply_hwmon.c > > b/drivers/power/supply/power_supply_hwmon.c > > new file mode 100644 > > index 000000000000..dca7f79fae6e > > --- /dev/null > > +++ b/drivers/power/supply/power_supply_hwmon.c > > @@ -0,0 +1,329 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * power_supply_hwmon.c - power supply hwmon support. > > + */ > > + > > +#include <linux/hwmon.h> > > +#include <linux/slab.h> > > +#include <linux/err.h> > > +#include <linux/power_supply.h> > > + > Alphabetic order ? > Sure, will do in v2. > > +struct power_supply_hwmon { > > + struct power_supply *psy; > > + unsigned long *props; > > +}; > > + > > +static int power_supply_hwmon_in_to_property(u32 attr) > > +{ > > + switch (attr) { > > + case hwmon_in_average: > > + return POWER_SUPPLY_PROP_VOLTAGE_AVG; > > + case hwmon_in_min: > > + return POWER_SUPPLY_PROP_VOLTAGE_MIN; > > + case hwmon_in_max: > > + return POWER_SUPPLY_PROP_VOLTAGE_MAX; > > + case hwmon_in_input: > > + return POWER_SUPPLY_PROP_VOLTAGE_NOW; > > + default: > > + break; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int power_supply_hwmon_curr_to_property(u32 attr) > > +{ > > + switch (attr) { > > + case hwmon_curr_average: > > + return POWER_SUPPLY_PROP_CURRENT_AVG; > > + case hwmon_curr_max: > > + return POWER_SUPPLY_PROP_CURRENT_MAX; > > + case hwmon_curr_input: > > + return POWER_SUPPLY_PROP_CURRENT_NOW; > > + default: > > + break; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int power_supply_hwmon_temp_to_property(u32 attr, int channel) > > +{ > > + if (channel) { > > + switch (attr) { > > + case hwmon_temp_input: > > + return POWER_SUPPLY_PROP_TEMP_AMBIENT; > > + case hwmon_temp_min_alarm: > > + return POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN; > > + case hwmon_temp_max_alarm: > > + return POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX; > > + default: > > + break; > > + } > > + } else { > > + switch (attr) { > > + case hwmon_temp_input: > > + return POWER_SUPPLY_PROP_TEMP; > > + case hwmon_temp_max: > > + return POWER_SUPPLY_PROP_TEMP_MAX; > > + case hwmon_temp_min: > > + return POWER_SUPPLY_PROP_TEMP_MIN; > > + case hwmon_temp_min_alarm: > > + return POWER_SUPPLY_PROP_TEMP_ALERT_MIN; > > + case hwmon_temp_max_alarm: > > + return POWER_SUPPLY_PROP_TEMP_ALERT_MAX; > > + default: > > + break; > > + } > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int > > +power_supply_hwmon_to_property(enum hwmon_sensor_types type, > > + u32 attr, int channel) > > +{ > > + switch (type) { > > + case hwmon_in: > > + return power_supply_hwmon_in_to_property(attr); > > + case hwmon_curr: > > + return power_supply_hwmon_curr_to_property(attr); > > + case hwmon_temp: > > + return power_supply_hwmon_temp_to_property(attr, channel); > > + default: > > + break; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static bool power_supply_hwmon_is_a_label(enum hwmon_sensor_types type, > > + u32 attr) > > +{ > > + return type == hwmon_temp && attr == hwmon_temp_label; > > +} > > + > > +static umode_t power_supply_hwmon_is_visible(const void *data, > > + enum hwmon_sensor_types type, > > + u32 attr, int channel) > > +{ > > + const struct power_supply_hwmon *psyhw = data; > > + int prop, is_writable; > > + > > + if (power_supply_hwmon_is_a_label(type, attr)) > > + return 0444; > > + > > + prop = power_supply_hwmon_to_property(type, attr, channel); > > + if (prop < 0 || !test_bit(prop, psyhw->props)) > > + return 0; > > + > > + is_writable = power_supply_property_is_writeable(psyhw->psy, prop); > > + > > + return (is_writable <= 0) ? 0444 : 0644; > > I a a bit concerned that this can result in writeable voltage/current/temp > values (not just for limits), which would be very undesirable. It might be > better to add another check to ensure that this does not happen. > OK, will do. > > +} > > + > > +static int power_supply_hwmon_read_string(struct device *dev, > > + enum hwmon_sensor_types type, > > + u32 attr, int channel, > > + const char **str) > > +{ > > + *str = channel ? "temp" : "temp ambient"; > > + return 0; > > +} > > + > > +static int > > +power_supply_hwmon_read(struct device *dev, enum hwmon_sensor_types type, > > + u32 attr, int channel, long *val) > > +{ > > + struct power_supply_hwmon *psyhw = dev_get_drvdata(dev); > > + struct power_supply *psy = psyhw->psy; > > + union power_supply_propval pspval; > > + int ret, prop; > > + > > + prop = power_supply_hwmon_to_property(type, attr, channel); > > + if (prop < 0) > > + return prop; > > + > > + ret = power_supply_get_property(psy, prop, &pspval); > > + if (ret) > > + return ret; > > + > > + switch (type) { > > + /* > > + * Both voltage and current is reported in units of > > + * microvolts/microamps, so we need to adjust it to > > + * milliamps(volts) > > + */ > > + case hwmon_curr: > > + case hwmon_in: > > + pspval.intval /= 1000; > > DIV_ROUND_CLOSEST() ? > Yeah, good idea, will do. > > + break; > > + /* > > + * Temp needs to be converted from 1/10 C to milli-C > > + */ > > + case hwmon_temp: > > + pspval.intval *= 100; > > intval is an int, so theoretically this could result in an overflow. > Sure, will change the code to use check_mul_overflow() > > > + break; > > + default: > > Wouldn't this be an error ? > Shouldn't happen, but adding a error path here won't hurt. > Personally I prefer direct value assignments. I don't see value in > updating pspval.intval first only to assign it to *val later. > This won't work once I convert the code to use check_mul_overflow() since it expects its argument to have the same type and "*val" is long. > > + break; > > + } > > + > > + *val = pspval.intval; > > + > > + return 0; > > +} > > + > > +static int > > +power_supply_hwmon_write(struct device *dev, enum hwmon_sensor_types type, > > + u32 attr, int channel, long val) > > +{ > > + struct power_supply_hwmon *psyhw = dev_get_drvdata(dev); > > + struct power_supply *psy = psyhw->psy; > > + union power_supply_propval pspval; > > + int prop; > > + > > + prop = power_supply_hwmon_to_property(type, attr, channel); > > + if (prop < 0) > > + return prop; > > + > > + pspval.intval = val; > > + > > + switch (type) { > > + /* > > + * Both voltage and current is reported in units of > > + * microvolts/microamps, so we need to adjust it to > > + * milliamps(volts) > > + */ > > + case hwmon_curr: > > + case hwmon_in: > > + pspval.intval *= 1000; > > Range checks ? This can result in an overflow. > Will add check_mul_overflow() here as well. > > + break; > > + /* > > + * Temp needs to be converted from 1/10 C to milli-C > > + */ > > + case hwmon_temp: > > + pspval.intval /= 100; > > + break; > > + default: > > + break; > > Wouldn't this be an error ? > Will add an error path in v2. > > + } > > + > > + return power_supply_set_property(psy, prop, &pspval); > > +} > > + > > +static const struct hwmon_ops power_supply_hwmon_ops = { > > + .is_visible = power_supply_hwmon_is_visible, > > + .read = power_supply_hwmon_read, > > + .write = power_supply_hwmon_write, > > + .read_string = power_supply_hwmon_read_string, > > +}; > > + > > +static const struct hwmon_channel_info *power_supply_hwmon_info[] = { > > + HWMON_CHANNEL_INFO(temp, > > + HWMON_T_LABEL | > > + HWMON_T_INPUT | > > + HWMON_T_MAX | > > + HWMON_T_MIN | > > + HWMON_T_MIN_ALARM | > > + HWMON_T_MIN_ALARM, > > + > > + HWMON_T_LABEL | > > + HWMON_T_INPUT | > > + HWMON_T_MIN_ALARM | > > + HWMON_T_LABEL | > > + HWMON_T_MAX_ALARM), > > + > > + HWMON_CHANNEL_INFO(curr, > > + HWMON_C_AVERAGE | > > + HWMON_C_MAX | > > + HWMON_C_INPUT), > > + > > + HWMON_CHANNEL_INFO(in, > > + HWMON_I_AVERAGE | > > + HWMON_I_MIN | > > + HWMON_I_MAX | > > + HWMON_I_INPUT), > > + NULL > > +}; > > + > > +static const struct hwmon_chip_info power_supply_hwmon_chip_info = { > > + .ops = &power_supply_hwmon_ops, > > + .info = power_supply_hwmon_info, > > +}; > > + > > +static void power_supply_hwmon_bitmap_free(void *data) > > +{ > > + bitmap_free(data); > > +} > > + > > +struct device *devm_power_supply_add_hwmon_sysfs(struct power_supply *psy) > > +{ > > + const struct power_supply_desc *desc = psy->desc; > > + struct power_supply_hwmon *psyhw; > > + struct device *dev = &psy->dev; > > + struct device *hwmon; > > + int ret, i; > > + > > + if (!devres_open_group(dev, NULL, GFP_KERNEL)) > > + return ERR_PTR(-ENOMEM); > > + > > + psyhw = devm_kzalloc(dev, sizeof(*psyhw), GFP_KERNEL); > > + if (!psyhw) { > > + ret = -ENOMEM; > > + goto error; > > + } > > + > > + psyhw->psy = psy; > > + psyhw->props = bitmap_zalloc(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG + 1, > > + GFP_KERNEL); > > + if (!psyhw->props) { > > + ret = -ENOMEM; > > + goto error; > > + } > > + > > + ret = devm_add_action(dev, power_supply_hwmon_bitmap_free, > > + psyhw->props); > > + if (ret) > > + goto error; > > + > > + for (i = 0; i < desc->num_properties; i++) { > > + const enum power_supply_property prop = desc->properties[i]; > > + > > + switch (prop) { > > + case POWER_SUPPLY_PROP_CURRENT_AVG: > > + case POWER_SUPPLY_PROP_CURRENT_MAX: > > + case POWER_SUPPLY_PROP_CURRENT_NOW: > > + case POWER_SUPPLY_PROP_TEMP: > > + case POWER_SUPPLY_PROP_TEMP_MAX: > > + case POWER_SUPPLY_PROP_TEMP_MIN: > > + case POWER_SUPPLY_PROP_TEMP_ALERT_MIN: > > + case POWER_SUPPLY_PROP_TEMP_ALERT_MAX: > > + case POWER_SUPPLY_PROP_TEMP_AMBIENT: > > + case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN: > > + case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX: > > + case POWER_SUPPLY_PROP_VOLTAGE_AVG: > > + case POWER_SUPPLY_PROP_VOLTAGE_MIN: > > + case POWER_SUPPLY_PROP_VOLTAGE_MAX: > > + case POWER_SUPPLY_PROP_VOLTAGE_NOW: > > + set_bit(prop, psyhw->props); > > + break; > > + default: > > + break; > > + } > > + } > > + > > + hwmon = devm_hwmon_device_register_with_info(dev, psy->desc->name, > > + psyhw, > > + &power_supply_hwmon_chip_info, > > + NULL); > > + ret = PTR_ERR_OR_ZERO(hwmon); > > + if (ret) > > + goto error; > > + > > + devres_remove_group(dev, NULL); > > Why devres_remove_group() and not devres_close_group() ? > That's id-less group that'll never be used again, closing it and keeping it around isn't really particularly useful to me. > > + return hwmon; > > Why return a pointer to the hwmon device and not just an error code ? > Just to expose created hwmon device. > > +error: > > + devres_release_group(dev, NULL); > > + return ERR_PTR(ret); > > +} > > diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h > > index d9c0c094f8a0..839abfa2c640 100644 > > --- a/include/linux/power_supply.h > > +++ b/include/linux/power_supply.h > > @@ -481,4 +481,15 @@ static inline bool power_supply_is_watt_property(enum > > power_supply_property psp) > > return 0; > > } > > > > +#ifdef CONFIG_POWER_SUPPLY_HWMON > > +extern struct device * > > +devm_power_supply_add_hwmon_sysfs(struct power_supply *psy); > > +#else > > +static struct device * > > +devm_power_supply_add_hwmon_sysfs(struct power_supply *psy) > > +{ > > + return 0; > > You might consider making the return code an int. Otherwise this gets > difficult > for the caller, who would have to check for IS_ERR() and NULL (if the device > pointer is supposed to be used for anything). > Sure, if removing access to created hwmon device is OK, I am more than happy to convert this to return an int. Thanks, Andrey Smirnov