diff mbox series

regulator (max5970): Add hwmon support

Message ID 20230830111319.3882281-1-Naresh.Solanki@9elements.com (mailing list archive)
State Changes Requested
Headers show
Series regulator (max5970): Add hwmon support | expand

Commit Message

Naresh Solanki Aug. 30, 2023, 11:13 a.m. UTC 
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>
---
 drivers/regulator/max5970-regulator.c | 119 ++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)


base-commit: 35d0d2350d774fecf596cfb2fb050559fe5e1850

Comments

Naresh Solanki Aug. 30, 2023, 7:14 p.m. UTC | #1 
Hi


On Wed, 30 Aug 2023 at 21:26, Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 8/30/23 04:13, 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>
> > ---
> >   drivers/regulator/max5970-regulator.c | 119 ++++++++++++++++++++++++++
> >   1 file changed, 119 insertions(+)
> >
> > diff --git a/drivers/regulator/max5970-regulator.c b/drivers/regulator/max5970-regulator.c
> > index b56a174cde3d..3a6f7c293526 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 +33,116 @@ 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, &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 max5970_data *ddata = dev_get_drvdata(dev);
> > +     struct regmap *regmap = dev_get_regmap(dev->parent, NULL);
> > +     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[channel]) >> 10;
> > +                     /* Convert the voltage meansurement across shunt resistor to current */
> > +                     *val = (*val * 1000) / ddata->shunt_micro_ohms[channel];
> > +                     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[channel], 10);
>
> Why do you use mul_u64_u32_shr() here but a direct shift above ?
There is possibility of overflow due to large value of ddata->mon_rng
>
> > +                     /* 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 max5970_data *ddata = (struct max5970_data *)data;
> > +
> > +     if (channel >= ddata->num_switches)
> > +             return 0;
> > +
> > +     switch (type) {
> > +     case hwmon_in:
> > +             switch (attr) {
> > +             case hwmon_in_input:
> > +                     return 0444;
>
>                 default:
>                         break;
Ack
>
> > +             }
> > +             break;
> > +     case hwmon_curr:
> > +             switch (attr) {
> > +             case hwmon_curr_input:
> > +                     /* Current measurement requires knowledge of the shunt resistor value. */
> > +                     if (ddata->shunt_micro_ohms[channel])
> > +                             return 0444;
>                 default:
>                         break;
Ack
>
> > +             }
> > +             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),
>
> Your call, but the chip does support limit and status registers, so you
> could add reporting those as well since you are at it, possibly even including
> notifications.
Will consider separate set of patch for this.
>
> > +     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;
> > @@ -432,6 +543,7 @@ static int max597x_regulator_probe(struct platform_device *pdev)
> >       struct regulator_config config = { };
> >       struct regulator_dev *rdev;
> >       struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES];
> > +     struct device *hwmon_dev;
> >       int num_switches;
> >       int ret, i;
> >
> > @@ -485,6 +597,13 @@ static int max597x_regulator_probe(struct platform_device *pdev)
> >               max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms;
> >       }
> >
> > +     hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970_hwmon", max597x,
> > +                                                      &max5970_chip_info, NULL);
>
> This makes the driver dependent on hwmon, so you either need a strict
>         depends on HWMON
> in Kconfig, or
>         depends on HWMON || HWMON=n
> and add #if IS_ENABLED(CONFIG_HWMON) as appropriate into the code.
Sure, will update accordingly. Thanks
>
>
> > +     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,
> >
> > base-commit: 35d0d2350d774fecf596cfb2fb050559fe5e1850
>
Guenter Roeck Aug. 30, 2023, 7:32 p.m. UTC | #2 
On 8/30/23 12:14, Naresh Solanki wrote:
> Hi
> 
[ ... ]
>>> +                     /*
>>> +                      * 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[channel], 10);
>>
>> Why do you use mul_u64_u32_shr() here but a direct shift above ?
> There is possibility of overflow due to large value of ddata->mon_rng

Does the right shift guarantee that the result fits into 32 bit ?

Thanks,
Guenter
Naresh Solanki Aug. 31, 2023, 8:56 a.m. UTC | #3 
Hi


On Thu, 31 Aug 2023 at 01:02, Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 8/30/23 12:14, Naresh Solanki wrote:
> > Hi
> >
> [ ... ]
> >>> +                     /*
> >>> +                      * 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[channel], 10);
> >>
> >> Why do you use mul_u64_u32_shr() here but a direct shift above ?
> > There is possibility of overflow due to large value of ddata->mon_rng
>
> Does the right shift guarantee that the result fits into 32 bit ?
Yes. Value in ddata->mon_rng can go upto 26bits, & ADC is 10 bit.
The 10 bit right shift(part of calculation) makes sure the result
never exceed 32 bit

Regards,
Naresh
>
> Thanks,
> Guenter
>
kernel test robot Sept. 1, 2023, 8 a.m. UTC | #4 
Hi Naresh,

kernel test robot noticed the following build errors:

[auto build test ERROR on 35d0d2350d774fecf596cfb2fb050559fe5e1850]

url:    https://github.com/intel-lab-lkp/linux/commits/Naresh-Solanki/regulator-max5970-Add-hwmon-support/20230831-035843
base:   35d0d2350d774fecf596cfb2fb050559fe5e1850
patch link:    https://lore.kernel.org/r/20230830111319.3882281-1-Naresh.Solanki%409elements.com
patch subject: [PATCH] regulator (max5970): Add hwmon support
config: x86_64-randconfig-004-20230901 (https://download.01.org/0day-ci/archive/20230901/202309011547.EoLU88a1-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230901/202309011547.EoLU88a1-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309011547.EoLU88a1-lkp@intel.com/

All errors (new ones prefixed by >>, old ones prefixed by <<):

WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-celtic.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-inuit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-roman.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/unicode/utf8data.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/unicode/utf8-selftest.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/isofs/isofs.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/smb/common/cifs_arc4.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/smb/common/cifs_md4.o
WARNING: modpost: missing MODULE_DESCRIPTION() in security/keys/trusted-keys/trusted.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/algif_hash.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/math/prime_numbers.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/video/backlight/rt4831-backlight.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/acpi/nfit/nfit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/acpi/custom_method.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/clk/clk_test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/clk/clk-gate_test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/regulator/max20411-regulator.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/regulator/rt4831-regulator.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/serial/8250/serial_cs.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/tty/n_gsm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/char/ppdev.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/base/regmap/regmap-kunit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/base/regmap/regmap-ram.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/base/regmap/regmap-raw-ram.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/base/regmap/regmap-spmi.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/block/loop.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/misc/open-dice.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/mfd/rt4831.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/mfd/intel_soc_pmic_bxtwc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/macintosh/mac_hid.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/host/nvme-core.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/host/nvme-fabrics.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/host/nvme-fc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvme/target/nvme-loop.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/mtd/chips/cfi_cmdset_0020.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/phy/phylink.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/phy/sfp.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/pcs/pcs-lynx.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/ethernet/qualcomm/emac/qcom-emac.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/ppp/ppp_async.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/ppp/bsd_comp.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/ppp/ppp_deflate.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/ppp/ppp_synctty.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/cdrom/cdrom.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/auxdisplay/charlcd.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/auxdisplay/hd44780_common.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/mon/usbmon.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/mxuport.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/navman.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/qcaux.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/usb-serial-simple.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/symbolserial.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/chipidea/ci_hdrc_msm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/libcomposite.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_acm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ss_lb.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/u_serial.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_obex.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/u_ether.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ncm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ecm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_eem.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ecm_subset.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_rndis.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_mass_storage.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_fs.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_hid.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_printer.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_tcm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/legacy/g_zero.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/legacy/g_dbgp.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/rtc/rtc-goldfish.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/isdn/mISDN/l1oip.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/isdn/hardware/mISDN/hfcsusb.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/mmc/core/pwrseq_simple.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/mmc/core/pwrseq_emmc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/gsmi.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/memconsole-x86-legacy.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/cbmem.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/platform/x86/intel/intel-vbtn.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/devfreq/governor_simpleondemand.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/devfreq/governor_performance.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/spmi/hisi-spmi-controller.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pcmcia/pcmcia_rsrc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/rpmsg/rpmsg_char.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/core/dev_addr_lists_test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/act_gate.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/sch_sfq.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/sch_tbf.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/sch_mqprio.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/sch_mqprio_lib.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/sch_etf.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/sched/cls_fw.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/xdp/xsk_diag.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/caif/caif.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/caif/chnl_net.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/caif/caif_socket.o
WARNING: modpost: missing MODULE_DESCRIPTION() in net/hsr/hsr.o
>> ERROR: modpost: "devm_hwmon_device_register_with_info" [drivers/regulator/max5970-regulator.ko] undefined!
kernel test robot Sept. 1, 2023, 8:11 a.m. UTC | #5 
Hi Naresh,

kernel test robot noticed the following build errors:

[auto build test ERROR on 35d0d2350d774fecf596cfb2fb050559fe5e1850]

url:    https://github.com/intel-lab-lkp/linux/commits/Naresh-Solanki/regulator-max5970-Add-hwmon-support/20230831-035843
base:   35d0d2350d774fecf596cfb2fb050559fe5e1850
patch link:    https://lore.kernel.org/r/20230830111319.3882281-1-Naresh.Solanki%409elements.com
patch subject: [PATCH] regulator (max5970): Add hwmon support
config: x86_64-buildonly-randconfig-001-20230901 (https://download.01.org/0day-ci/archive/20230901/202309011524.JIWSmpfT-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230901/202309011524.JIWSmpfT-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309011524.JIWSmpfT-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: devm_hwmon_device_register_with_info
   >>> referenced by max5970-regulator.c
   >>>               drivers/regulator/max5970-regulator.o:(max597x_regulator_probe) in archive vmlinux.a
diff mbox series

Patch

diff --git a/drivers/regulator/max5970-regulator.c b/drivers/regulator/max5970-regulator.c
index b56a174cde3d..3a6f7c293526 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 +33,116 @@  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, &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 max5970_data *ddata = dev_get_drvdata(dev);
+	struct regmap *regmap = dev_get_regmap(dev->parent, NULL);
+	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[channel]) >> 10;
+			/* Convert the voltage meansurement across shunt resistor to current */
+			*val = (*val * 1000) / ddata->shunt_micro_ohms[channel];
+			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[channel], 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 max5970_data *ddata = (struct max5970_data *)data;
+
+	if (channel >= ddata->num_switches)
+		return 0;
+
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_input:
+			return 0444;
+		}
+		break;
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+			/* Current measurement requires knowledge of the shunt resistor value. */
+			if (ddata->shunt_micro_ohms[channel])
+				return 0444;
+		}
+		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;
@@ -432,6 +543,7 @@  static int max597x_regulator_probe(struct platform_device *pdev)
 	struct regulator_config config = { };
 	struct regulator_dev *rdev;
 	struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES];
+	struct device *hwmon_dev;
 	int num_switches;
 	int ret, i;
 
@@ -485,6 +597,13 @@  static int max597x_regulator_probe(struct platform_device *pdev)
 		max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms;
 	}
 
+	hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970_hwmon", max597x,
+							 &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,