On 9/22/20 8:35 AM, Vadim Pasternak wrote:
> Add support for mp295 device from Monolithic Power Systems, Inc. (MPS)
> vendor. This is a dual-loop, digital, multi-phase controller.
> This device:
> - Supports two power rail.
> - Provides 8 pulse-width modulations (PWMs), and can be configured up
> to 8-phase operation for rail 1 and up to 4-phase operation for rail
> 2.
> - Supports two pages 0 and 1 for telemetry and also pages 2 and 3 for
> configuration.
> - Can configured VOUT readout in direct or VID format and allows
> setting of different formats on rails 1 and 2. For VID the following
> protocols are available: VR13 mode with 5-mV DAC; VR13 mode with
> 10-mV DAC, IMVP9 mode with 5-mV DAC.
>
> Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxx>
> ---
> drivers/hwmon/pmbus/Kconfig | 9 +
> drivers/hwmon/pmbus/Makefile | 1 +
> drivers/hwmon/pmbus/mp2975.c | 825 +++++++++++++++++++++++++++++++++++++++++++
Documentation/hwmon/mp2975 is missing.
> 3 files changed, 835 insertions(+)
> create mode 100644 drivers/hwmon/pmbus/mp2975.c
>
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index e35db489b76f..1e6157e85437 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -200,6 +200,15 @@ config SENSORS_MAX8688
> This driver can also be built as a module. If so, the module will
> be called max8688.
>
> +config SENSORS_MP2975
> + tristate "MPS MP2975"
> + help
> + If you say yes here you get hardware monitoring support for MPS
> + MP2975 Dual Loop Digital Multi-Phase Controller.
> +
> + This driver can also be built as a module. If so, the module will
> + be called mp2975.
> +
> config SENSORS_PXE1610
> tristate "Infineon PXE1610"
> help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index c4b15db996ad..0e2832e73cfc 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_SENSORS_MAX20751) += max20751.o
> obj-$(CONFIG_SENSORS_MAX31785) += max31785.o
> obj-$(CONFIG_SENSORS_MAX34440) += max34440.o
> obj-$(CONFIG_SENSORS_MAX8688) += max8688.o
> +obj-$(CONFIG_SENSORS_MP2975) += mp2975.o
> obj-$(CONFIG_SENSORS_PXE1610) += pxe1610.o
> obj-$(CONFIG_SENSORS_TPS40422) += tps40422.o
> obj-$(CONFIG_SENSORS_TPS53679) += tps53679.o
> diff --git a/drivers/hwmon/pmbus/mp2975.c b/drivers/hwmon/pmbus/mp2975.c
> new file mode 100644
> index 000000000000..7f67fab35e3e
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/mp2975.c
> @@ -0,0 +1,825 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers
> + *
> + * Copyright (C) 2020 Nvidia Technologies Ltd.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include "pmbus.h"
> +
> +/* Vendor specific registers. */
> +#define MP2975_MFR_APS_HYS_R2 0x0d
> +#define MP2975_MFR_SLOPE_TRIM3 0x1d
> +#define MP2975_MFR_VR_MULTI_CONFIG_R1 0x0d
> +#define MP2975_MFR_VR_MULTI_CONFIG_R2 0x1d
> +#define MP2975_MFR_APS_DECAY_ADV 0x56
> +#define MP2975_MFR_DC_LOOP_CTRL 0x59
> +#define MP2975_MFR_OCP_UCP_PHASE_SET 0x65
> +#define MP2975_MFR_VR_CONFIG1 0x68
> +#define MP2975_MFR_READ_CS1_2 0x82
> +#define MP2975_MFR_READ_CS3_4 0x83
> +#define MP2975_MFR_READ_CS5_6 0x84
> +#define MP2975_MFR_READ_CS7_8 0x85
> +#define MP2975_MFR_READ_CS9_10 0x86
> +#define MP2975_MFR_READ_CS11_12 0x87
> +#define MP2975_MFR_READ_IOUT_PK 0x90
> +#define MP2975_MFR_READ_POUT_PK 0x91
> +#define MP2975_MFR_READ_VREF_R1 0xa1
> +#define MP2975_MFR_READ_VREF_R2 0xa3
> +#define MP2975_MFR_OVP_TH_SET 0xe5
> +#define MP2975_MFR_UVP_SET 0xe6
> +
> +#define MP2975_VOUT_FORMAT BIT(15)
> +#define MP2975_VID_STEP_SEL_R1 BIT(4)
> +#define MP2975_IMVP9_EN_R1 BIT(13)
> +#define MP2975_VID_STEP_SEL_R2 BIT(3)
> +#define MP2975_IMVP9_EN_R2 BIT(12)
> +#define MP2975_PRT_THRES_DIV_OV_EN BIT(14)
> +#define MP2975_DRMOS_KCS GENMASK(13, 12)
> +#define MP2975_PROT_DEV_OV_OFF 10
> +#define MP2975_PROT_DEV_OV_ON 5
> +#define MP2975_SENSE_AMPL BIT(11)
> +#define MP2975_SENSE_AMPL_UNIT 1
> +#define MP2975_SENSE_AMPL_HALF 2
> +#define MP2975_VIN_UV_LIMIT_UNIT 8
> +
> +#define MP2975_PSC_VOLTAGE_OUT 0x40
> +#define MP2975_MAX_PHASE_RAIL1 8
> +#define MP2975_MAX_PHASE_RAIL2 4
> +#define MP2975_PAGE_NUM 2
> +
> +#define MP2975_RAIL2_FUNC (PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | \
> + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | \
> + PMBUS_PHASE_VIRTUAL)
> +
> +struct mp2975_data {
> + struct pmbus_driver_info info;
> + int vout_scale;
> + int vid_step[MP2975_PAGE_NUM];
> + int vref[MP2975_PAGE_NUM];
> + int vref_off[MP2975_PAGE_NUM];
> + int vout_max[MP2975_PAGE_NUM];
> + int vout_ov_fixed[MP2975_PAGE_NUM];
> + int vout_format[MP2975_PAGE_NUM];
> + int curr_sense_gain[MP2975_PAGE_NUM];
> +};
> +
> +#define to_mp2975_data(x) container_of(x, struct mp2975_data, info)
> +
> +static int mp2975_read_byte_data(struct i2c_client *client, int page, int reg)
> +{
> + switch (reg) {
> + case PMBUS_VOUT_MODE:
> + /*
> + * Enforce VOUT direct format, since device allows to set the
> + * different formats for the different rails. Conversion from
> + * VID to direct provided by driver internally, in case it is
> + * necessary.
> + */
> + return MP2975_PSC_VOLTAGE_OUT;
Please use standard defines where qvailable (here: PB_VOUT_MODE_DIRECT).
> + default:
> + return -ENODATA;
> + }
> +}
> +
> +static int
> +mp2975_read_word_helper(struct i2c_client *client, int page, int phase, u8 reg,
> + u16 mask)
> +{
> + int ret = pmbus_read_word_data(client, page, phase, reg);
> +
> + return (ret > 0) ? ret & mask : ret;
> +}
> +
> +static int
> +mp2975_vid2direct(int vrf, int val)
> +{
> + switch (vrf) {
> + case vr12:
> + if (val >= 0x01)
> + return 250 + (val - 1) * 5;
> + break;
> + case vr13:
> + if (val >= 0x01)
> + return 500 + (val - 1) * 10;
> + break;
> + case imvp9:
> + if (val >= 0x01)
> + return 200 + (val - 1) * 10;
> + break;
> + default:
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int
> +mp2975_read_phase(struct i2c_client *client, struct mp2975_data *data,
> + int page, int phase, u8 reg)
> +{
> + int shift = 0, ph_curr, ret;
> + u16 mask;
> +
> + if ((phase + 1) % MP2975_PAGE_NUM) {
> + mask = GENMASK(7, 0);
> + } else {
> + mask = GENMASK(15, 8);
> + shift = 8;
> + }
> +
> + ret = mp2975_read_word_helper(client, page, phase, reg, mask);
> + if (ret < 0)
> + return ret;
> +
> + ret >>= shift;
Personally I am not a friend of such complex code.
ret = pmbus_read_word_data(client, page, phase, reg);
if (ret < 0)
return ret;
if (!((phase + 1) % MP2975_PAGE_NUM))
ret >>= 8;
ret &= 0xff;
would accomplish the same and be much easier to read.
But I understand this is a bit POV, so I'll let it go.
> +
> + /*
> + * Output value is calculated as: (READ_CSx / 80 – 1.23) / (Kcs * Rcs)
> + * where:
> + * - Kcs is the DrMOS current sense gain of power stage, which is
> + * obtained from the register MP2975_MFR_VR_CONFIG1, bits 13-12 with
> + * the following selection of DrMOS (data->curr_sense_gain[page]):
> + * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A.
> + * - Rcs is the internal phase current sense resistor which is constant
> + * value 1kΩ.
> + */
> + ph_curr = DIV_ROUND_CLOSEST(ret * 100 - 9840, 100) * 100;
I am at loss here. Why not just the following ?
ph_curr = ret * 100 - 9800;
Or even this ?
ph_curr = ret * 100 - 9840;
I mean, what is the point of "9840" if the next thing to do
is the most complicated way possible to drop the 40 ?
> +
> + /*
> + * Current phase sensing, providing by the device is not accurate
> + * for the light load. This because sampling of current occurrence of
> + * bit weight has a big deviation for light load. For handling such
> + * case phase current is represented as the maximum between the value
> + * calculated above and total rail current divided by number phases.
> + */
> + ret = pmbus_read_word_data(client, page, phase, PMBUS_READ_IOUT);
> + if (ret < 0)
> + return ret;
> +
> + return max_t(int, DIV_ROUND_CLOSEST(ret, data->info.phases[page]),
> + DIV_ROUND_CLOSEST(ph_curr, data->curr_sense_gain[page]));
> +}
> +
> +static int
> +mp2975_read_phases(struct i2c_client *client, struct mp2975_data *data,
> + int page, int phase)
> +{
> + int ret;
> +
> + if (page) {
> + switch (phase) {
> + case 0 ... 1:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS7_8);
> + break;
> + case 2 ... 3:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS9_10);
> + break;
> + case 4 ... 5:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS11_12);
> + break;
> + default:
> + return -ENODATA;
> + }
> + } else {
> + switch (phase) {
> + case 0 ... 1:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS1_2);
> + break;
> + case 2 ... 3:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS3_4);
> + break;
> + case 4 ... 5:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS5_6);
> + break;
> + case 6 ... 7:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS7_8);
> + break;
> + case 8 ... 9:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS9_10);
> + break;
> + case 10 ... 11:
> + ret = mp2975_read_phase(client, data, page, phase,
> + MP2975_MFR_READ_CS11_12);
> + break;
> + default:
> + return -ENODATA;
> + }
> + }
> + return ret;
> +}
> +
> +static int mp2975_read_word_data(struct i2c_client *client, int page,
> + int phase, int reg)
> +{
> + const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
> + struct mp2975_data *data = to_mp2975_data(info);
> + int ret;
> +
> + switch (reg) {
> + case PMBUS_OT_FAULT_LIMIT:
> + ret = mp2975_read_word_helper(client, page, phase, reg,
> + GENMASK(7, 0));
> + break;
> + case PMBUS_VIN_OV_FAULT_LIMIT:
> + ret = mp2975_read_word_helper(client, page, phase, reg,
> + GENMASK(7, 0));
> + ret = (ret > 0) ? DIV_ROUND_CLOSEST(ret,
> + MP2975_VIN_UV_LIMIT_UNIT) :
> + ret;
Elsewhere you use
if (ret < 0)
return ret;
ret = DIV_ROUND_CLOSEST(ret, MP2975_VIN_UV_LIMIT_UNIT);
which I think is much easier to read. Please do that here as well.
> + break;
> + case PMBUS_VOUT_OV_FAULT_LIMIT:
> + /*
> + * Register provides two values for over-voltage protection
> + * threshold for fixed (ovp2) and tracking (ovp1) modes. The
> + * minimum of these two values is provided as over-voltage
> + * fault alarm.
> + */
> + ret = mp2975_read_word_helper(client, page, phase,
> + MP2975_MFR_OVP_TH_SET,
> + GENMASK(2, 0));
> + if (ret < 0)
> + return ret;
> +
> + ret = min_t(int, data->vout_max[page] + 50 * (ret + 1),
> + data->vout_ov_fixed[page]);
> + break;
> + case PMBUS_VOUT_UV_FAULT_LIMIT:
> + ret = mp2975_read_word_helper(client, page, phase,
> + MP2975_MFR_UVP_SET,
> + GENMASK(2, 0));
> + if (ret < 0)
> + return ret;
> +
> + ret = DIV_ROUND_CLOSEST(data->vref[page] * 10 - 50 *
> + (ret + 1) * data->vout_scale, 10);
> + break;
> + case PMBUS_READ_VOUT:
> + ret = mp2975_read_word_helper(client, page, phase, reg,
> + GENMASK(11, 0));
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * READ_VOUT can be provided in VID or direct format. The
> + * format type is specified by bit 15 of the register
> + * MP2975_MFR_DC_LOOP_CTRL. The driver enforces VOUT direct
> + * format, since device allows to set the different formats for
> + * the different rails and also all VOUT limits registers are
> + * provided in a direct format. In case format is VID - convert
> + * to direct.
> + */
> + if (data->vout_format[page] == vid)
> + ret = mp2975_vid2direct(info->vrm_version[page], ret);
> + break;
> + case PMBUS_VIRT_READ_POUT_MAX:
> + ret = mp2975_read_word_helper(client, page, phase,
> + MP2975_MFR_READ_POUT_PK,
> + GENMASK(12, 0));
if (ret < 0)
return ret;
same below several times.
> + ret = DIV_ROUND_CLOSEST(ret, 4);
> + break;
> + case PMBUS_VIRT_READ_IOUT_MAX:
> + ret = mp2975_read_word_helper(client, page, phase,
> + MP2975_MFR_READ_IOUT_PK,
> + GENMASK(12, 0));
> + ret = DIV_ROUND_CLOSEST(ret, 4);
> + break;
> + case PMBUS_READ_IOUT:
> + ret = mp2975_read_phases(client, data, page, phase);
> + break;
> + case PMBUS_UT_WARN_LIMIT:
> + fallthrough;
fallthrough; is unnecessary if case statements follow each other.
> + case PMBUS_UT_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_VIN_UV_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_VIN_UV_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_VOUT_UV_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_VOUT_OV_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_VIN_OV_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_IIN_OC_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_IIN_OC_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_IOUT_OC_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_IOUT_OC_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_IOUT_UC_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_POUT_OP_FAULT_LIMIT:
> + fallthrough;
> + case PMBUS_POUT_OP_WARN_LIMIT:
> + fallthrough;
> + case PMBUS_PIN_OP_WARN_LIMIT:
> + return -ENXIO;
> + default:
> + return -ENODATA;
> + }
> +
> + return ret;
> +}
> +
> +static int mp2975_identify_multiphase_rail2(struct i2c_client *client)
> +{
> + int ret;
> +
> + /* Identify multiphase for rail 2 - could be from 0 to 4.
> + * In case phase number is zero – only page zero is supported
> + */
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
> + if (ret < 0)
> + return ret;
> +
> + /* Identify multiphase for rail 2 - could be from 0 to 4. */
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_VR_MULTI_CONFIG_R2);
Please handle errors first.
if (ret < 0)
return ret;
...
> + if (ret >= 0) {
> + ret &= GENMASK(2, 0);
> + return (ret >= 4) ? 4 : ret;
> + }
> +
> + return ret;
> +}
> +
> +static void mp2975_set_phase_rail1(struct pmbus_driver_info *info)
> +{
> + int i;
> +
> + for (i = 0 ; i < info->phases[0]; i++)
> + info->pfunc[i] = PMBUS_HAVE_IOUT;
> +}
> +
> +static void mp2975_set_phase_rail2(struct pmbus_driver_info *info)
> +{
> + int max_rail, i;
> +
> + /* Set phases for rail 2 from upper to lower. */
> + max_rail = info->phases[1] % (MP2975_MAX_PHASE_RAIL2 - 1);
> + for (i = 1; i <= max_rail; i++)
> + info->pfunc[MP2975_MAX_PHASE_RAIL1 - i] = PMBUS_HAVE_IOUT;
> +}
> +
> +static int mp2975_set_multiphase_rail2(struct pmbus_driver_info *info)
> +{
> + switch (info->phases[1]) {
> + case 1 ... 7:
> + mp2975_set_phase_rail2(info);
> + return 0;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int
> +mp2975_identify_multiphase(struct i2c_client *client, struct mp2975_data *data,
> + struct pmbus_driver_info *info)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
> + if (ret < 0)
> + return ret;
> +
> + /* Identify multiphase for rail 1 - could be from 1 to 8. */
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_VR_MULTI_CONFIG_R1);
> + if (ret > 0)
> + info->phases[0] = ret & GENMASK(3, 0);
> + else
> + return (ret) ? ret : -EINVAL;
Please handle errors first.
if (ret < 0)
return ret;
if (ret == 0)
return -EINVAL;
...
> +
> + /*
> + * The device provides a total of 8 PWM pins, and can be configured
> + * to different phase count applications for rail 1 and rail 2.
> + * Rail 1 can be set to 8 phases, while rail 2 can only be set to 4
> + * phases at most. When rail 1’s phase count is configured as 0, rail
> + * 1 operates with 1-phase DCM. When rail 2 phase count is configured
> + * as 0, rail 2 is disabled.
> + */
> + switch (info->phases[0]) {
> + case 1 ... 4:
> + mp2975_set_phase_rail1(info);
> + return mp2975_set_multiphase_rail2(info);
> + case 5:
> + mp2975_set_phase_rail1(info);
> + switch (info->phases[1]) {
> + case 1 ... 3:
> + return mp2975_set_multiphase_rail2(info);
> + default:
> + return 0;
> + }
> + case 6:
> + mp2975_set_phase_rail1(info);
> + switch (info->phases[1]) {
> + case 1 ... 2:
> + return mp2975_set_multiphase_rail2(info);
> + default:
> + return 0;
> + }
> + case 7:
> + mp2975_set_phase_rail1(info);
> + switch (info->phases[1]) {
> + case 1:
> + return mp2975_set_multiphase_rail2(info);
> + default:
> + return 0;
> + }
> + case 8:
> + mp2975_set_phase_rail1(info);
> + return 0;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int
> +mp2975_identify_vid(struct i2c_client *client, struct mp2975_data *data,
> + struct pmbus_driver_info *info, u32 reg, int page,
> + u32 imvp_bit, u32 vr_bit)
> +{
> + int ret;
> +
> + /* Identify VID mode and step selection. */
> + ret = i2c_smbus_read_word_data(client, reg);
> + if (ret < 0)
> + return ret;
> +
> + if (ret & imvp_bit) {
> + info->vrm_version[page] = imvp9;
> + data->vid_step[page] = MP2975_PROT_DEV_OV_OFF;
> + } else if (ret & vr_bit) {
> + info->vrm_version[page] = vr12;
> + data->vid_step[page] = MP2975_PROT_DEV_OV_ON;
> + } else {
> + info->vrm_version[page] = vr13;
> + data->vid_step[page] = MP2975_PROT_DEV_OV_OFF;
> + }
> +
> + return 0;
> +}
> +
> +static int
> +mp2975_identify_rails_vid(struct i2c_client *client, struct mp2975_data *data,
> + struct pmbus_driver_info *info)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);
> + if (ret < 0)
> + return ret;
> +
> + /* Identify VID mode for rail 1. */
> + ret = mp2975_identify_vid(client, data, info,
> + MP2975_MFR_VR_MULTI_CONFIG_R1, 0,
> + MP2975_IMVP9_EN_R1, MP2975_VID_STEP_SEL_R1);
> + if (ret < 0)
> + return ret;
> +
> + /* Identify VID mode for rail 2, if connected. */
> + if (info->phases[1])
> + ret = mp2975_identify_vid(client, data, info,
> + MP2975_MFR_VR_MULTI_CONFIG_R2, 1,
> + MP2975_IMVP9_EN_R2,
> + MP2975_VID_STEP_SEL_R2);
> + return ret;
> +}
> +
> +static int
> +mp2975_current_sense_gain_get(struct i2c_client *client,
> + struct mp2975_data *data)
> +{
> + int i, ret;
> +
> + /*
> + * Obtain DrMOS current sense gain of power stage from the register
> + * MP2975_MFR_VR_CONFIG1, bits 13-12. The value is selected as below:
> + * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other
> + * values are invalid.
> + */
> + for (i = 0 ; i < data->info.pages; i++) {
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
> + if (ret < 0)
> + return ret;
> + ret = i2c_smbus_read_word_data(client,
> + MP2975_MFR_VR_CONFIG1);
> + if (ret < 0)
> + return ret;
> +
> + switch ((ret & MP2975_DRMOS_KCS) >> 12) {
> + case 0:
> + data->curr_sense_gain[i] = 50;
> + break;
> + case 1:
> + data->curr_sense_gain[i] = 85;
> + break;
> + case 2:
> + data->curr_sense_gain[i] = 97;
> + break;
> + case 3:
> + data->curr_sense_gain[i] = 100;
> + break;
> + default:
> + return -EINVAL;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int
> +mp2975_vref_get(struct i2c_client *client, struct mp2975_data *data,
> + struct pmbus_driver_info *info)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 3);
> + if (ret < 0)
> + return ret;
> +
> + /* Get voltage reference value for rail 1. */
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_READ_VREF_R1);
> + if (ret < 0)
> + return ret;
> +
> + data->vref[0] = ret * data->vid_step[0];
> +
> + /* Get voltage reference value for rail 2, if connected. */
> + if (data->info.pages == MP2975_PAGE_NUM) {
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_READ_VREF_R2);
> + if (ret < 0)
> + return ret;
> +
> + data->vref[1] = ret * data->vid_step[1];
> + }
> + return 0;
> +}
> +
> +static int
> +mp2975_vref_offset_get(struct i2c_client *client, struct mp2975_data *data,
> + int page)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_OVP_TH_SET);
> + if (ret < 0)
> + return ret;
> +
> + switch ((ret & GENMASK(5, 3)) >> 3) {
> + case 1:
> + data->vref_off[page] = 140;
> + break;
> + case 2:
> + data->vref_off[page] = 220;
> + break;
> + case 4:
> + data->vref_off[page] = 400;
> + break;
> + default:
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int
> +mp2975_vout_max_get(struct i2c_client *client, struct mp2975_data *data,
> + struct pmbus_driver_info *info, int page)
> +{
> + int ret;
> +
> + /* Get maximum reference voltage of VID-DAC in VID format. */
> + ret = i2c_smbus_read_word_data(client, PMBUS_VOUT_MAX);
> + if (ret < 0)
> + return ret;
> +
> + data->vout_max[page] = mp2975_vid2direct(info->vrm_version[page], ret &
> + GENMASK(8, 0));
> + return 0;
> +}
> +
> +static int
> +mp2975_identify_vout_format(struct i2c_client *client,
> + struct mp2975_data *data, int page)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_DC_LOOP_CTRL);
> + if (ret < 0)
> + return ret;
> +
> + if (ret & MP2975_VOUT_FORMAT)
> + data->vout_format[page] = vid;
> + else
> + data->vout_format[page] = direct;
> + return 0;
> +}
> +
> +static int
> +mp2975_vout_ov_scale_get(struct i2c_client *client, struct mp2975_data *data,
> + struct pmbus_driver_info *info)
> +{
> + int thres_dev, sense_ampl, ret;
> +
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * Get divider for over- and under-voltage protection thresholds
> + * configuration from the Advanced Options of Auto Phase Shedding and
> + * decay register.
> + */
> + ret = i2c_smbus_read_word_data(client, MP2975_MFR_APS_DECAY_ADV);
> + if (ret >= 0)
> + thres_dev = ret & MP2975_PRT_THRES_DIV_OV_EN ?
> + MP2975_PROT_DEV_OV_ON : MP2975_PROT_DEV_OV_OFF;
> + else
> + return ret;
> +
> + /* Select the gain of remote sense amplifier. */
> + ret = i2c_smbus_read_word_data(client, PMBUS_VOUT_SCALE_LOOP);
> + if (ret >= 0)
> + sense_ampl = ret & MP2975_SENSE_AMPL ? MP2975_SENSE_AMPL_HALF :
> + MP2975_SENSE_AMPL_UNIT;
> + else
> + return ret;
> +
> + data->vout_scale = sense_ampl * thres_dev;
> +
> + return 0;
> +}
> +
> +static int
> +mp2975_vout_per_rail_config_get(struct i2c_client *client,
> + struct mp2975_data *data,
> + struct pmbus_driver_info *info)
> +{
> + int i, ret;
> +
> + for (i = 0; i < data->info.pages; i++) {
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
> + if (ret < 0)
> + return ret;
> +
> + /* Obtain voltage reference offsets. */
> + ret = mp2975_vref_offset_get(client, data, i);
> + if (ret < 0)
> + goto config_get_fail;
Please no goto to a return statement.
> +
> + /* Obtain maximum voltage values. */
> + ret = mp2975_vout_max_get(client, data, info, i);
> + if (ret < 0)
> + goto config_get_fail;
> +
> + /*
> + * Get VOUT format for READ_VOUT command : VID or direct.
> + * Pages on same device can be configured with different
> + * formats.
> + */
> + ret = mp2975_identify_vout_format(client, data, i);
> + if (ret < 0)
> + goto config_get_fail;
> +
> + /*
> + * Set over-voltage fixed value. Thresholds are provided as
> + * fixed value, and tracking value. The minimum of them are
> + * exposed as over-voltage critical threshold.
> + */
> + data->vout_ov_fixed[i] = data->vref[i] +
> + DIV_ROUND_CLOSEST(data->vref_off[i] *
> + data->vout_scale,
> + 10);
> + }
> +
> +config_get_fail:
> + return ret;
> +}
> +
> +static struct pmbus_driver_info mp2975_info = {
> + .pages = 1,
> + .format[PSC_VOLTAGE_IN] = linear,
> + .format[PSC_VOLTAGE_OUT] = direct,
> + .format[PSC_TEMPERATURE] = direct,
> + .format[PSC_CURRENT_IN] = linear,
> + .format[PSC_CURRENT_OUT] = direct,
> + .format[PSC_POWER] = direct,
> + .m[PSC_TEMPERATURE] = 1,
> + .m[PSC_VOLTAGE_OUT] = 1,
> + .R[PSC_VOLTAGE_OUT] = 3,
> + .m[PSC_CURRENT_OUT] = 1,
> + .m[PSC_POWER] = 1,
> + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
> + PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> + PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |
> + PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_PHASE_VIRTUAL,
> + .read_byte_data = mp2975_read_byte_data,
> + .read_word_data = mp2975_read_word_data,
> +};
> +
> +static int mp2975_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct pmbus_driver_info *info;
> + struct mp2975_data *data;
> + int ret;
> +
> + data = devm_kzalloc(&client->dev, sizeof(struct mp2975_data),
> + GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + memcpy(&data->info, &mp2975_info, sizeof(*info));
> + info = &data->info;
> +
> + /* Identify multiphase configuration for rail 2. */
> + ret = mp2975_identify_multiphase_rail2(client);
> + if (ret < 0)
> + goto probe_failed;
> +
> + if (ret) {
> + /* Two railes are connected. */
> + data->info.pages = MP2975_PAGE_NUM;
> + data->info.phases[1] = ret;
> + data->info.func[1] = MP2975_RAIL2_FUNC;
> + }
> +
> + /* Identify multiphase configuration. */
> + ret = mp2975_identify_multiphase(client, data, info);
> + if (ret)
> + goto probe_failed;
> +
> + /* Identify VID setting per rail. */
> + ret = mp2975_identify_rails_vid(client, data, info);
> + if (ret < 0)
> + goto probe_failed;
> +
> + /* Obtain current sense gain of power stage. */
> + ret = mp2975_current_sense_gain_get(client, data);
> + if (ret)
> + goto probe_failed;
> +
> + /* Obtain voltage reference values. */
> + ret = mp2975_vref_get(client, data, info);
> + if (ret)
> + goto probe_failed;
> +
> + /* Obtain vout over-voltage scales. */
> + ret = mp2975_vout_ov_scale_get(client, data, info);
> + if (ret < 0)
> + goto probe_failed;
> +
> + /* Obtain offsets, maximum and format for vout. */
> + ret = mp2975_vout_per_rail_config_get(client, data, info);
> + if (ret)
> + goto probe_failed;
> +
> + return pmbus_do_probe(client, id, info);
> +
> +probe_failed:
> + return ret;
> +}
> +
> +static const struct i2c_device_id mp2975_id[] = {
> + {"mp2975", 0},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, mp2975_id);
> +
> +static const struct of_device_id __maybe_unused mp2975_of_match[] = {
> + {.compatible = "mps,mp2975"},
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, mp2975_of_match);
> +
> +static struct i2c_driver mp2975_driver = {
> + .driver = {
> + .name = "mp2975",
> + .of_match_table = of_match_ptr(mp2975_of_match),
> + },
> + .probe = mp2975_probe,
> + .remove = pmbus_do_remove,
> + .id_table = mp2975_id,
> +};
> +
> +module_i2c_driver(mp2975_driver);
> +
> +MODULE_AUTHOR("Vadim Pasternak <vadimp@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("PMBus driver for MPS MP2975 device");
> +MODULE_LICENSE("GPL");
>
