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In-Reply-To: <1658242365-27797-3-git-send-email-u0084500@gmail.com>
From:   ChiYuan Huang <u0084500@gmail.com>
Date:   Fri, 29 Jul 2022 11:38:44 +0800
Message-ID: <CADiBU38OGHyAHReKhB7i_p6PUkGE5eCiN_G9_Es-DKtG0Yc71A@mail.gmail.com>
Subject: Re: [PATCH v8 2/3] iio: adc: Add rtq6056 support
To:     Jonathan Cameron <jic23@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc:     Lars-Peter Clausen <lars@metafoo.de>,
        cy_huang <cy_huang@richtek.com>,
        linux-iio <linux-iio@vger.kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>
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Hi, Jonathan:

cy_huang <u0084500@gmail.com> =E6=96=BC 2022=E5=B9=B47=E6=9C=8819=E6=97=A5 =
=E9=80=B1=E4=BA=8C =E6=99=9A=E4=B8=8A10:52=E5=AF=AB=E9=81=93=EF=BC=9A
>
> From: ChiYuan Huang <cy_huang@richtek.com>
>
> Add Richtek rtq6056 supporting.
>
> It can be used for the system to monitor load current and power with 16-b=
it
> resolution.
>
> Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> ---
> Since v8
> - Instead of 'integraion_time' for voltage channel, use per channel sampl=
ing
>   frequency to be more generic.
For the v8 change, is there still anything need to be refined?
>
> Since v7
> - Use 'DEFINE_RUNTIME_DEV_PM_OPS' to replace the explicit declaration of =
pm_ops.
>
> Since v6
> - Remove specific rtq6056 ABI document.
> - Remove the redundant blank line.
> - To prevent the race condition for attribute wrtie and shunt resistor wr=
ite,
>   use 'iio_device_claim_direct_mode' API.
> - Refine the order for 'action_reset' and 'pm_runtime'.
> - Fix text typo in comment like as ohm to Ohm and timea to time.
>
> Since v5
> - Fix kernel version text for ABI.
>
> Since v4
> - Add '__aligned(8)' for timestamp member in buffer_trigger_handler funct=
ion.
> - Declare timestamp from 'int64_t' to more unified 's64'.
>
> Since v3
> - Refine pm_runtime API calling order in 'read_channel' API.
> - Fix vshunt wrong scale for divider.
> - Refine the comment text.
> - Use 'devm_add_action_or_reset' to decrease the code usage in probe
>   function.
> - Use RUNTIME_PM_OPS to replace SET_RUNTIME_PM_OPS.
> - minor fix for the comma.
> - Use pm_ptr to replace the direct assigned pm_ops.
>
> Since v2
> - Rename file from 'rtq6056-adc' to 'rtq6056'.
> - Refine the ABI, if generic already defined it, remove it and check the =
channel
>   report unit.
> - Add copyright text.
> - include the correct header.
> - change the property parsing name.
> - To use iio_chan_spec address field.
> - Refine each channel separate and shared_by_all.
> - Use pm_runtime and pm_runtime_autosuspend.
> - Remove the shutdown callback. From the HW suggestion, it's not recommen=
ded to
>   use battery as the power supply.
> - Check all scale unit (voltage->mV, current->mA, power->milliWatt).
> - Use the read_avail to provide the interface for attribute value list.
> - Add comma for the last element in the const integer array.
> - Refine each ADC label text.
> - In read_label callback, replace snprintf to sysfs_emit.
> ---
>  drivers/iio/adc/Kconfig   |  15 ++
>  drivers/iio/adc/Makefile  |   1 +
>  drivers/iio/adc/rtq6056.c | 661 ++++++++++++++++++++++++++++++++++++++++=
++++++
>  3 files changed, 677 insertions(+)
>  create mode 100644 drivers/iio/adc/rtq6056.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 48ace74..caebd1a 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -908,6 +908,21 @@ config ROCKCHIP_SARADC
>           To compile this driver as a module, choose M here: the
>           module will be called rockchip_saradc.
>
> +config RICHTEK_RTQ6056
> +       tristate "Richtek RTQ6056 Current and Power Monitor ADC"
> +       depends on I2C
> +       select REGMAP_I2C
> +       select IIO_BUFFER
> +       select IIO_TRIGGERED_BUFFER
> +       help
> +         Say yes here to enable RQT6056 ADC support.
> +         RTQ6056 is a high accuracy current-sense monitor with I2C and S=
MBus
> +         compatible interface, and the device provides full information =
for
> +         system by reading out the load current and power.
> +
> +         This driver can also be built as a module. If so, the module wi=
ll be
> +         called rtq6056.
> +
>  config RZG2L_ADC
>         tristate "Renesas RZ/G2L ADC driver"
>         depends on ARCH_RZG2L || COMPILE_TEST
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 39d806f..cda7580 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -84,6 +84,7 @@ obj-$(CONFIG_QCOM_PM8XXX_XOADC) +=3D qcom-pm8xxx-xoadc.=
o
>  obj-$(CONFIG_RCAR_GYRO_ADC) +=3D rcar-gyroadc.o
>  obj-$(CONFIG_RN5T618_ADC) +=3D rn5t618-adc.o
>  obj-$(CONFIG_ROCKCHIP_SARADC) +=3D rockchip_saradc.o
> +obj-$(CONFIG_RICHTEK_RTQ6056) +=3D rtq6056.o
>  obj-$(CONFIG_RZG2L_ADC) +=3D rzg2l_adc.o
>  obj-$(CONFIG_SC27XX_ADC) +=3D sc27xx_adc.o
>  obj-$(CONFIG_SPEAR_ADC) +=3D spear_adc.o
> diff --git a/drivers/iio/adc/rtq6056.c b/drivers/iio/adc/rtq6056.c
> new file mode 100644
> index 00000000..c1b2e8d
> --- /dev/null
> +++ b/drivers/iio/adc/rtq6056.c
> @@ -0,0 +1,661 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2022 Richtek Technology Corp.
> + *
> + * ChiYuan Huang <cy_huang@richtek.com>
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +#include <linux/util_macros.h>
> +
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#define RTQ6056_REG_CONFIG     0x00
> +#define RTQ6056_REG_SHUNTVOLT  0x01
> +#define RTQ6056_REG_BUSVOLT    0x02
> +#define RTQ6056_REG_POWER      0x03
> +#define RTQ6056_REG_CURRENT    0x04
> +#define RTQ6056_REG_CALIBRATION        0x05
> +#define RTQ6056_REG_MASKENABLE 0x06
> +#define RTQ6056_REG_ALERTLIMIT 0x07
> +#define RTQ6056_REG_MANUFACTID 0xFE
> +#define RTQ6056_REG_DIEID      0xFF
> +
> +#define RTQ6056_VENDOR_ID      0x1214
> +#define RTQ6056_DEFAULT_CONFIG 0x4127
> +#define RTQ6056_CONT_ALLON     7
> +
> +enum {
> +       RTQ6056_CH_VSHUNT =3D 0,
> +       RTQ6056_CH_VBUS,
> +       RTQ6056_CH_POWER,
> +       RTQ6056_CH_CURRENT,
> +       RTQ6056_MAX_CHANNEL
> +};
> +
> +enum {
> +       F_OPMODE =3D 0,
> +       F_VSHUNTCT,
> +       F_VBUSCT,
> +       F_AVG,
> +       F_RESET,
> +       F_MAX_FIELDS
> +};
> +
> +struct rtq6056_priv {
> +       struct device *dev;
> +       struct regmap *regmap;
> +       struct regmap_field *rm_fields[F_MAX_FIELDS];
> +       u32 shunt_resistor_uohm;
> +       int vshuntct_us;
> +       int vbusct_us;
> +       int avg_sample;
> +};
> +
> +static const struct reg_field rtq6056_reg_fields[F_MAX_FIELDS] =3D {
> +       [F_OPMODE] =3D REG_FIELD(RTQ6056_REG_CONFIG, 0, 2),
> +       [F_VSHUNTCT] =3D REG_FIELD(RTQ6056_REG_CONFIG, 3, 5),
> +       [F_VBUSCT] =3D REG_FIELD(RTQ6056_REG_CONFIG, 6, 8),
> +       [F_AVG] =3D REG_FIELD(RTQ6056_REG_CONFIG, 9, 11),
> +       [F_RESET] =3D REG_FIELD(RTQ6056_REG_CONFIG, 15, 15),
> +};
> +
> +static const struct iio_chan_spec rtq6056_channels[RTQ6056_MAX_CHANNEL +=
 1] =3D {
> +       {
> +               .type =3D IIO_VOLTAGE,
> +               .indexed =3D 1,
> +               .channel =3D 0,
> +               .address =3D RTQ6056_REG_SHUNTVOLT,
> +               .info_mask_separate =3D BIT(IIO_CHAN_INFO_RAW) |
> +                                     BIT(IIO_CHAN_INFO_SCALE) |
> +                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +               .info_mask_separate_available =3D BIT(IIO_CHAN_INFO_SAMP_=
FREQ),
> +               .info_mask_shared_by_all =3D BIT(IIO_CHAN_INFO_OVERSAMPLI=
NG_RATIO),
> +               .info_mask_shared_by_all_available =3D BIT(IIO_CHAN_INFO_=
OVERSAMPLING_RATIO),
> +               .scan_index =3D 0,
> +               .scan_type =3D {
> +                       .sign =3D 's',
> +                       .realbits =3D 16,
> +                       .storagebits =3D 16,
> +                       .endianness =3D IIO_CPU,
> +               },
> +       },
> +       {
> +               .type =3D IIO_VOLTAGE,
> +               .indexed =3D 1,
> +               .channel =3D 1,
> +               .address =3D RTQ6056_REG_BUSVOLT,
> +               .info_mask_separate =3D BIT(IIO_CHAN_INFO_RAW) |
> +                                     BIT(IIO_CHAN_INFO_SCALE) |
> +                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +               .info_mask_separate_available =3D BIT(IIO_CHAN_INFO_SAMP_=
FREQ),
> +               .info_mask_shared_by_all =3D BIT(IIO_CHAN_INFO_OVERSAMPLI=
NG_RATIO),
> +               .info_mask_shared_by_all_available =3D BIT(IIO_CHAN_INFO_=
OVERSAMPLING_RATIO),
> +               .scan_index =3D 1,
> +               .scan_type =3D {
> +                       .sign =3D 'u',
> +                       .realbits =3D 16,
> +                       .storagebits =3D 16,
> +                       .endianness =3D IIO_CPU,
> +               },
> +       },
> +       {
> +               .type =3D IIO_POWER,
> +               .indexed =3D 1,
> +               .channel =3D 2,
> +               .address =3D RTQ6056_REG_POWER,
> +               .info_mask_separate =3D BIT(IIO_CHAN_INFO_RAW) |
> +                                     BIT(IIO_CHAN_INFO_SCALE) |
> +                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +               .info_mask_shared_by_all =3D BIT(IIO_CHAN_INFO_OVERSAMPLI=
NG_RATIO),
> +               .info_mask_shared_by_all_available =3D BIT(IIO_CHAN_INFO_=
OVERSAMPLING_RATIO),
> +               .scan_index =3D 2,
> +               .scan_type =3D {
> +                       .sign =3D 'u',
> +                       .realbits =3D 16,
> +                       .storagebits =3D 16,
> +                       .endianness =3D IIO_CPU,
> +               },
> +       },
> +       {
> +               .type =3D IIO_CURRENT,
> +               .indexed =3D 1,
> +               .channel =3D 3,
> +               .address =3D RTQ6056_REG_CURRENT,
> +               .info_mask_separate =3D BIT(IIO_CHAN_INFO_RAW) |
> +                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +               .info_mask_shared_by_all =3D BIT(IIO_CHAN_INFO_OVERSAMPLI=
NG_RATIO),
> +               .info_mask_shared_by_all_available =3D BIT(IIO_CHAN_INFO_=
OVERSAMPLING_RATIO),
> +               .scan_index =3D 3,
> +               .scan_type =3D {
> +                       .sign =3D 's',
> +                       .realbits =3D 16,
> +                       .storagebits =3D 16,
> +                       .endianness =3D IIO_CPU,
> +               },
> +       },
> +       IIO_CHAN_SOFT_TIMESTAMP(RTQ6056_MAX_CHANNEL),
> +};
> +
> +static int rtq6056_adc_read_channel(struct rtq6056_priv *priv,
> +                                   struct iio_chan_spec const *ch,
> +                                   int *val)
> +{
> +       struct device *dev =3D priv->dev;
> +       unsigned int addr =3D ch->address;
> +       unsigned int regval;
> +       int ret;
> +
> +       pm_runtime_get_sync(dev);
> +       ret =3D regmap_read(priv->regmap, addr, &regval);
> +       pm_runtime_mark_last_busy(dev);
> +       pm_runtime_put(dev);
> +       if (ret)
> +               return ret;
> +
> +       /* Power and VBUS is unsigned 16-bit, others are signed 16-bit */
> +       if (addr =3D=3D RTQ6056_REG_BUSVOLT || addr =3D=3D RTQ6056_REG_PO=
WER)
> +               *val =3D regval;
> +       else
> +               *val =3D sign_extend32(regval, 16);
> +
> +       return IIO_VAL_INT;
> +}
> +
> +static int rtq6056_adc_read_scale(struct iio_chan_spec const *ch, int *v=
al,
> +                                 int *val2)
> +{
> +       switch (ch->address) {
> +       case RTQ6056_REG_SHUNTVOLT:
> +               /* VSHUNT lsb  2.5uV */
> +               *val =3D 2500;
> +               *val2 =3D 1000000;
> +               return IIO_VAL_FRACTIONAL;
> +       case RTQ6056_REG_BUSVOLT:
> +               /* VBUS lsb 1.25mV */
> +               *val =3D 1250;
> +               *val2 =3D 1000;
> +               return IIO_VAL_FRACTIONAL;
> +       case RTQ6056_REG_POWER:
> +               /* Power lsb 25mW */
> +               *val =3D 25;
> +               return IIO_VAL_INT;
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +/*
> + * Sample frequency for channel VSHUNT and VBUS. The indices correspond
> + * with the bit value expected by the chip. And it can be found at
> + * https://www.richtek.com/assets/product_file/RTQ6056/DSQ6056-00.pdf
> + */
> +static const int rtq6056_samp_freq_list[] =3D {
> +       7194, 4926, 3717, 1904, 964, 485, 243, 122,
> +};
> +
> +static int rtq6056_adc_set_samp_freq(struct rtq6056_priv *priv,
> +                                    struct iio_chan_spec const *ch, int =
val)
> +{
> +       struct regmap_field *rm_field;
> +       unsigned int selector;
> +       int *ct, ret;
> +
> +       if (val > 7194 || val < 122)
> +               return -EINVAL;
> +
> +       if (ch->address =3D=3D RTQ6056_REG_SHUNTVOLT) {
> +               rm_field =3D priv->rm_fields[F_VSHUNTCT];
> +               ct =3D &priv->vshuntct_us;
> +       } else if (ch->address =3D=3D RTQ6056_REG_BUSVOLT) {
> +               rm_field =3D priv->rm_fields[F_VBUSCT];
> +               ct =3D &priv->vbusct_us;
> +       } else
> +               return -EINVAL;
> +
> +       selector =3D find_closest_descending(val, rtq6056_samp_freq_list,
> +                                          ARRAY_SIZE(rtq6056_samp_freq_l=
ist));
> +
> +       ret =3D regmap_field_write(rm_field, selector);
> +       if (ret)
> +               return ret;
> +
> +       *ct =3D 1000000 / rtq6056_samp_freq_list[selector];
> +
> +       return 0;
> +}
> +
> +/*
> + * Available averaging rate for rtq6056. The indices correspond with the=
 bit
> + * value expected by the chip. And it can be found at
> + * https://www.richtek.com/assets/product_file/RTQ6056/DSQ6056-00.pdf
> + */
> +static const int rtq6056_avg_sample_list[] =3D {
> +       1, 4, 16, 64, 128, 256, 512, 1024,
> +};
> +
> +static int rtq6056_adc_set_average(struct rtq6056_priv *priv, int val)
> +{
> +       unsigned int selector;
> +       int ret;
> +
> +       if (val > 1024 || val < 1)
> +               return -EINVAL;
> +
> +       selector =3D find_closest(val, rtq6056_avg_sample_list,
> +                               ARRAY_SIZE(rtq6056_avg_sample_list));
> +
> +       ret =3D regmap_field_write(priv->rm_fields[F_AVG], selector);
> +       if (ret)
> +               return ret;
> +
> +       priv->avg_sample =3D rtq6056_avg_sample_list[selector];
> +
> +       return 0;
> +}
> +
> +static int rtq6056_adc_get_sample_freq(struct rtq6056_priv *priv,
> +                                      struct iio_chan_spec const *ch, in=
t *val)
> +{
> +       int sample_time;
> +
> +       if (ch->address =3D=3D RTQ6056_REG_SHUNTVOLT)
> +               sample_time =3D priv->vshuntct_us;
> +       else if (ch->address =3D=3D RTQ6056_REG_BUSVOLT)
> +               sample_time =3D priv->vbusct_us;
> +       else {
> +               sample_time =3D priv->vshuntct_us + priv->vbusct_us;
> +               sample_time *=3D priv->avg_sample;
> +       }
> +
> +       *val =3D 1000000 / sample_time;
> +
> +       return IIO_VAL_INT;
> +}
> +
> +static int rtq6056_adc_read_raw(struct iio_dev *indio_dev,
> +                               struct iio_chan_spec const *chan, int *va=
l,
> +                               int *val2, long mask)
> +{
> +       struct rtq6056_priv *priv =3D iio_priv(indio_dev);
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_RAW:
> +               return rtq6056_adc_read_channel(priv, chan, val);
> +       case IIO_CHAN_INFO_SCALE:
> +               return rtq6056_adc_read_scale(chan, val, val2);
> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +               *val =3D priv->avg_sample;
> +               return IIO_VAL_INT;
> +       case IIO_CHAN_INFO_SAMP_FREQ:
> +               return rtq6056_adc_get_sample_freq(priv, chan, val);
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +static int rtq6056_adc_read_avail(struct iio_dev *indio_dev,
> +                                 struct iio_chan_spec const *chan,
> +                                 const int **vals, int *type, int *lengt=
h,
> +                                 long mask)
> +{
> +       switch (mask) {
> +       case IIO_CHAN_INFO_SAMP_FREQ:
> +               *vals =3D rtq6056_samp_freq_list;
> +               *type =3D IIO_VAL_INT;
> +               *length =3D ARRAY_SIZE(rtq6056_samp_freq_list);
> +               return IIO_AVAIL_LIST;
> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +               *vals =3D rtq6056_avg_sample_list;
> +               *type =3D IIO_VAL_INT;
> +               *length =3D ARRAY_SIZE(rtq6056_avg_sample_list);
> +               return IIO_AVAIL_LIST;
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +static int rtq6056_adc_write_raw(struct iio_dev *indio_dev,
> +                                struct iio_chan_spec const *chan, int va=
l,
> +                                int val2, long mask)
> +{
> +       struct rtq6056_priv *priv =3D iio_priv(indio_dev);
> +       int ret;
> +
> +       ret =3D iio_device_claim_direct_mode(indio_dev);
> +       if (ret)
> +               return ret;
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_SAMP_FREQ:
> +               ret =3D rtq6056_adc_set_samp_freq(priv, chan, val);
> +               break;
> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +               ret =3D rtq6056_adc_set_average(priv, val);
> +               break;
> +       default:
> +               ret =3D -EINVAL;
> +               break;
> +       }
> +
> +       iio_device_release_direct_mode(indio_dev);
> +
> +       return ret;
> +}
> +
> +static const char *rtq6056_channel_labels[RTQ6056_MAX_CHANNEL] =3D {
> +       [RTQ6056_CH_VSHUNT] =3D "Vshunt",
> +       [RTQ6056_CH_VBUS] =3D "Vbus",
> +       [RTQ6056_CH_POWER] =3D "Power",
> +       [RTQ6056_CH_CURRENT] =3D "Current",
> +};
> +
> +static int rtq6056_adc_read_label(struct iio_dev *indio_dev,
> +                                 struct iio_chan_spec const *chan,
> +                                 char *label)
> +{
> +       return sysfs_emit(label, "%s\n", rtq6056_channel_labels[chan->cha=
nnel]);
> +}
> +
> +static int rtq6056_set_shunt_resistor(struct rtq6056_priv *priv,
> +                                     int resistor_uohm)
> +{
> +       unsigned int calib_val;
> +       int ret;
> +
> +       if (resistor_uohm <=3D 0) {
> +               dev_err(priv->dev, "Invalid resistor [%d]\n", resistor_uo=
hm);
> +               return -EINVAL;
> +       }
> +
> +       /* calibration =3D 5120000 / (Rshunt (uOhm) * current lsb (1mA)) =
*/
> +       calib_val =3D 5120000 / resistor_uohm;
> +       ret =3D regmap_write(priv->regmap, RTQ6056_REG_CALIBRATION, calib=
_val);
> +       if (ret)
> +               return ret;
> +
> +       priv->shunt_resistor_uohm =3D resistor_uohm;
> +
> +       return 0;
> +}
> +
> +static ssize_t shunt_resistor_show(struct device *dev,
> +                                  struct device_attribute *attr, char *b=
uf)
> +{
> +       struct rtq6056_priv *priv =3D iio_priv(dev_to_iio_dev(dev));
> +       int vals[2] =3D { priv->shunt_resistor_uohm, 1000000 };
> +
> +       return iio_format_value(buf, IIO_VAL_FRACTIONAL, 1, vals);
> +}
> +
> +static ssize_t shunt_resistor_store(struct device *dev,
> +                                   struct device_attribute *attr,
> +                                   const char *buf, size_t len)
> +{
> +       struct iio_dev *indio_dev =3D dev_to_iio_dev(dev);
> +       struct rtq6056_priv *priv =3D iio_priv(indio_dev);
> +       int val, val_fract, ret;
> +
> +       ret =3D iio_device_claim_direct_mode(indio_dev);
> +       if (ret)
> +               return ret;
> +
> +       ret =3D iio_str_to_fixpoint(buf, 100000, &val, &val_fract);
> +       if (ret)
> +               goto out_store;
> +
> +       ret =3D rtq6056_set_shunt_resistor(priv, val * 1000000 + val_frac=
t);
> +
> +out_store:
> +       iio_device_release_direct_mode(indio_dev);
> +
> +       return ret ?: len;
> +}
> +
> +static IIO_DEVICE_ATTR_RW(shunt_resistor, 0);
> +
> +static struct attribute *rtq6056_attributes[] =3D {
> +       &iio_dev_attr_shunt_resistor.dev_attr.attr,
> +       NULL
> +};
> +
> +static const struct attribute_group rtq6056_attribute_group =3D {
> +       .attrs =3D rtq6056_attributes,
> +};
> +
> +static const struct iio_info rtq6056_info =3D {
> +       .attrs =3D &rtq6056_attribute_group,
> +       .read_raw =3D rtq6056_adc_read_raw,
> +       .read_avail =3D rtq6056_adc_read_avail,
> +       .write_raw =3D rtq6056_adc_write_raw,
> +       .read_label =3D rtq6056_adc_read_label,
> +};
> +
> +static irqreturn_t rtq6056_buffer_trigger_handler(int irq, void *p)
> +{
> +       struct iio_poll_func *pf =3D p;
> +       struct iio_dev *indio_dev =3D pf->indio_dev;
> +       struct rtq6056_priv *priv =3D iio_priv(indio_dev);
> +       struct device *dev =3D priv->dev;
> +       struct {
> +               u16 vals[RTQ6056_MAX_CHANNEL];
> +               s64 timestamp __aligned(8);
> +       } data;
> +       unsigned int raw;
> +       int i =3D 0, bit, ret;
> +
> +       memset(&data, 0, sizeof(data));
> +
> +       pm_runtime_get_sync(dev);
> +
> +       for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->mas=
klength) {
> +               unsigned int addr =3D rtq6056_channels[bit].address;
> +
> +               ret =3D regmap_read(priv->regmap, addr, &raw);
> +               if (ret)
> +                       goto out;
> +
> +               data.vals[i++] =3D raw;
> +       }
> +
> +       iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time=
_ns(indio_dev));
> +
> +out:
> +       pm_runtime_mark_last_busy(dev);
> +       pm_runtime_put(dev);
> +
> +       iio_trigger_notify_done(indio_dev->trig);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static void rtq6056_enter_shutdown_state(void *dev)
> +{
> +       struct rtq6056_priv *priv =3D dev_get_drvdata(dev);
> +
> +       /* Enter shutdown state */
> +       regmap_field_write(priv->rm_fields[F_OPMODE], 0);
> +}
> +
> +static bool rtq6056_is_readable_reg(struct device *dev, unsigned int reg=
)
> +{
> +       switch (reg) {
> +       case RTQ6056_REG_CONFIG ... RTQ6056_REG_ALERTLIMIT:
> +       case RTQ6056_REG_MANUFACTID ... RTQ6056_REG_DIEID:
> +               return true;
> +       default:
> +               return false;
> +       }
> +}
> +
> +static bool rtq6056_is_writeable_reg(struct device *dev, unsigned int re=
g)
> +{
> +       switch (reg) {
> +       case RTQ6056_REG_CONFIG:
> +       case RTQ6056_REG_CALIBRATION ... RTQ6056_REG_ALERTLIMIT:
> +               return true;
> +       default:
> +               return false;
> +       }
> +}
> +
> +static const struct regmap_config rtq6056_regmap_config =3D {
> +       .reg_bits =3D 8,
> +       .val_bits =3D 16,
> +       .val_format_endian =3D REGMAP_ENDIAN_BIG,
> +       .max_register =3D RTQ6056_REG_DIEID,
> +       .readable_reg =3D rtq6056_is_readable_reg,
> +       .writeable_reg =3D rtq6056_is_writeable_reg,
> +};
> +
> +static int rtq6056_probe(struct i2c_client *i2c)
> +{
> +       struct iio_dev *indio_dev;
> +       struct rtq6056_priv *priv;
> +       struct device *dev =3D &i2c->dev;
> +       struct regmap *regmap;
> +       unsigned int vendor_id, shunt_resistor_uohm;
> +       int ret;
> +
> +       if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_WORD_DA=
TA))
> +               return -EOPNOTSUPP;
> +
> +       indio_dev =3D devm_iio_device_alloc(dev, sizeof(*priv));
> +       if (!indio_dev)
> +               return -ENOMEM;
> +
> +       priv =3D iio_priv(indio_dev);
> +       priv->dev =3D dev;
> +       priv->vshuntct_us =3D priv->vbusct_us =3D 1037;
> +       priv->avg_sample =3D 1;
> +       i2c_set_clientdata(i2c, priv);
> +
> +       regmap =3D devm_regmap_init_i2c(i2c, &rtq6056_regmap_config);
> +       if (IS_ERR(regmap))
> +               return dev_err_probe(dev, PTR_ERR(regmap),
> +                                    "Failed to init regmap\n");
> +
> +       priv->regmap =3D regmap;
> +
> +       ret =3D regmap_read(regmap, RTQ6056_REG_MANUFACTID, &vendor_id);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to get manufacturer info\n")=
;
> +
> +       if (vendor_id !=3D RTQ6056_VENDOR_ID)
> +               return dev_err_probe(dev, -ENODEV,
> +                                    "Invalid vendor id 0x%04x\n", vendor=
_id);
> +
> +       ret =3D devm_regmap_field_bulk_alloc(dev, regmap, priv->rm_fields=
,
> +                                          rtq6056_reg_fields, F_MAX_FIEL=
DS);
> +       if (ret)
> +               return dev_err_probe(dev, ret, "Failed to init regmap fie=
ld\n");
> +
> +       /*
> +        * By default, configure average sample as 1, bus and shunt conve=
rsion
> +        * time as 1037 microsecond, and operating mode to all on.
> +        */
> +       ret =3D regmap_write(regmap, RTQ6056_REG_CONFIG, RTQ6056_DEFAULT_=
CONFIG);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to enable continuous sensing=
\n");
> +
> +       ret =3D devm_add_action_or_reset(dev, rtq6056_enter_shutdown_stat=
e, dev);
> +       if (ret)
> +               return ret;
> +
> +       pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
> +       pm_runtime_use_autosuspend(dev);
> +       pm_runtime_set_active(dev);
> +       pm_runtime_mark_last_busy(dev);
> +       ret =3D devm_pm_runtime_enable(dev);
> +       if (ret)
> +               return dev_err_probe(dev, ret, "Failed to enable pm_runti=
me\n");
> +
> +       /* By default, use 2000 micro-Ohm resistor */
> +       shunt_resistor_uohm =3D 2000;
> +       device_property_read_u32(dev, "shunt-resistor-micro-ohms",
> +                                &shunt_resistor_uohm);
> +
> +       ret =3D rtq6056_set_shunt_resistor(priv, shunt_resistor_uohm);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to init shunt resistor\n");
> +
> +       indio_dev->name =3D "rtq6056";
> +       indio_dev->modes =3D INDIO_DIRECT_MODE;
> +       indio_dev->channels =3D rtq6056_channels;
> +       indio_dev->num_channels =3D ARRAY_SIZE(rtq6056_channels);
> +       indio_dev->info =3D &rtq6056_info;
> +
> +       ret =3D devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
> +                                             rtq6056_buffer_trigger_hand=
ler,
> +                                             NULL);
> +       if (ret)
> +               return dev_err_probe(dev, ret,
> +                                    "Failed to allocate iio trigger buff=
er\n");
> +
> +       return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static int rtq6056_runtime_suspend(struct device *dev)
> +{
> +       struct rtq6056_priv *priv =3D dev_get_drvdata(dev);
> +
> +       /* Configure to shutdown mode */
> +       return regmap_field_write(priv->rm_fields[F_OPMODE], 0);
> +}
> +
> +static int rtq6056_runtime_resume(struct device *dev)
> +{
> +       struct rtq6056_priv *priv =3D dev_get_drvdata(dev);
> +       int sample_rdy_time_us, ret;
> +
> +       ret =3D regmap_field_write(priv->rm_fields[F_OPMODE], RTQ6056_CON=
T_ALLON);
> +       if (ret)
> +               return ret;
> +
> +       sample_rdy_time_us =3D priv->vbusct_us + priv->vshuntct_us;
> +       sample_rdy_time_us *=3D priv->avg_sample;
> +
> +       usleep_range(sample_rdy_time_us, sample_rdy_time_us + 100);
> +
> +       return 0;
> +}
> +
> +static DEFINE_RUNTIME_DEV_PM_OPS(rtq6056_pm_ops, rtq6056_runtime_suspend=
,
> +                                rtq6056_runtime_resume, NULL);
> +
> +static const struct of_device_id rtq6056_device_match[] =3D {
> +       { .compatible =3D "richtek,rtq6056" },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(of, rtq6056_device_match);
> +
> +static struct i2c_driver rtq6056_driver =3D {
> +       .driver =3D {
> +               .name =3D "rtq6056",
> +               .of_match_table =3D rtq6056_device_match,
> +               .pm =3D pm_ptr(&rtq6056_pm_ops),
> +       },
> +       .probe_new =3D rtq6056_probe,
> +};
> +module_i2c_driver(rtq6056_driver);
> +
> +MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
> +MODULE_DESCRIPTION("Richtek RTQ6056 Driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>