Re: [PATCH v6 1/2] hwmon: (pmbus) Add support for MPS MP2949A

Guenter Roeck
2021-07-02T14:59:50Z

On 7/2/21 12:31 AM, ainux.wang@gmail.com wrote:
> From: "Ainux.Wang" <ainux.wang@gmail.com>
>
> Add support for MP2949A device from Monolithic Power Systems, Inc. (MPS).
> This is a triple-loop, digital, multi-phase controller.
> This device:
> - Supports up to three power rail.
> - Provides 6 pulse-width modulations (PWMs), and can be configured up
> to 6-phase operation for Rail A , up to 2-phase operation for Rail B
> and up to 1-phase operation for Rail C.
> - The PMBus registers are distributed into three pages: Page 0, Page 1,
> Page 2. Page 0 contains the registers for Rail A and most of the common
> settings for all of the rails. Page 1 contains register information for
> Rail B. Page 2 contains register information for Rail C.
> - The MP2949A supports both 5mV VID step and 10mv VID step for IMVP8 and
> IMVP9.
>
> Signed-off-by: Ainux.Wang <ainux.wang@gmail.com>
> ---
> Documentation/hwmon/index.rst | 1 +
> Documentation/hwmon/mp2949a.rst | 44 +++++++++++
> drivers/hwmon/pmbus/Kconfig | 9 +++
> drivers/hwmon/pmbus/Makefile | 1 +
> drivers/hwmon/pmbus/mp2949a.c | 136 ++++++++++++++++++++++++++++++++
> 5 files changed, 191 insertions(+)
> create mode 100644 Documentation/hwmon/mp2949a.rst
> create mode 100644 drivers/hwmon/pmbus/mp2949a.c
>
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index bc01601ea81a..e62161c0f01e 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -138,6 +138,7 @@ Hardware Monitoring Kernel Drivers
> mcp3021
> menf21bmc
> mlxreg-fan
> + mp2949a
> mp2888
> mp2975
> nct6683
> diff --git a/Documentation/hwmon/mp2949a.rst b/Documentation/hwmon/mp2949a.rst
> new file mode 100644
> index 000000000000..0235dec70f63
> --- /dev/null
> +++ b/Documentation/hwmon/mp2949a.rst
> @@ -0,0 +1,44 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +Kernel driver mp2949a
> +====================
> +
> +Supported chips:
> +
> + * MPS MP2949A
> +
> + Prefix: 'mp2949a'
> +
> +Author:
> +
> + Ainux Wang <ainux.wang@gmail.com>
> +
> +Description
> +-----------
> +
> +This driver implements support for Monolithic Power Systems, Inc. (MPS)
> +triple-loop, digital, multi-phase controller MP2949A.
> +
> +This device:
> +
> +- Supports up to three power rail.
> +- Provides 6 pulse-width modulations (PWMs), and can be configured for
> + to 6-phase operation for Rail A , up to 2-phase operation for Rail B,
> + and up to 1-phase operation for Rail C.
> +- The PMBus registers are distributed into three pages: Page 0, Page 1,
> + Page 2. Page 0 contains the registers for Rail A and most of the common
> + settings for all of the rails. Page 1 contains register information for
> + Rail B. Page 2 contains register information for Rail C.
> +- The MP2949A supports both 5mV VID step and 10mv VID step for IMVP8 and
> + IMVP9.
> +
> +Device supports:
> +
> +- SVID interface.
> +- PMBus rev 1.2 interface.
> +
> +Device supports direct format for reading output power.
> +Device supports linear format for reading input voltage, output current,
> +and temperature.
> +Device supports VID for reading output voltage.
> +The below VID modes are supported: VR12, VR13, IMVP8, IMVP9.
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index ffb609cee3a4..d3a521bead3e 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -258,6 +258,15 @@ config SENSORS_MAX8688
> This driver can also be built as a module. If so, the module will
> be called max8688.
>
> +config SENSORS_MP2949A
> + tristate "MPS MP2949A"
> + help
> + If you say yes here you get hardware monitoring support for MPS
> + MP2949A Triple Loop Digital Multi-Phase Controller.
> +
> + This driver can also be built as a module. If so, the module will
> + be called mp2949a.
> +
> config SENSORS_MP2888
> tristate "MPS MP2888"
> help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 0ed4d596a948..bfdfb599c8ba 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -29,6 +29,7 @@ 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-$(CONFIG_SENSORS_MP2949A) += mp2949a.o
> obj-$(CONFIG_SENSORS_MP2888) += mp2888.o
> obj-$(CONFIG_SENSORS_MP2975) += mp2975.o
> obj-$(CONFIG_SENSORS_PM6764TR) += pm6764tr.o
> diff --git a/drivers/hwmon/pmbus/mp2949a.c b/drivers/hwmon/pmbus/mp2949a.c
> new file mode 100644
> index 000000000000..8f8dd3235298
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/mp2949a.c
> @@ -0,0 +1,136 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Hardware monitoring driver for Monolithic Power Systems MP2949A
> + *
> + * Copyright (c) 2021 Lemote Technologies. All rights reserved.
> + * Copyright (c) 2021 Ainux <ainux.wang@gmail.com>
> + */
> +
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include "pmbus.h"
> +
> +#define MP2949A_PAGE_NUM 3
> +
> +#define MP2949A_MFR_VR_CONFIG 0xE4
> +
> +static int mp2949a_read_byte_data(struct i2c_client *client, int page, int reg)
> +{
> + switch (reg) {
> + /*
> + * This chip do not support the VOUT_MODE, STATUS_BYTE command,
> + * but return some random data when reading.
> + */
> + case PMBUS_VOUT_MODE:
> + case PMBUS_STATUS_BYTE:
> + return -ENXIO;
> + default:
> + return -ENODATA;
> + }
> +}
> +
> +static int mp2949a_read_word_data(struct i2c_client *client, int page,
> + int phase, int reg)
> +{
> +
> + switch (reg) {
> + /*
> + * This chip do not support STATUS_WORD command,
> + * but return some random data when reading.
> + */
> + case PMBUS_STATUS_WORD:
> + return -ENXIO;

One of the status registers should be simulated. See other patch
for details.

> + default:
> + return -ENODATA;
> + }
> +}
> +
> +static int mp2949a_identify(struct i2c_client *client,
> + struct pmbus_driver_info *info)
> +{
> + int i, ret;
> +
> + for (i = 0; i < MP2949A_PAGE_NUM; i++) {
> + ret = pmbus_read_byte_data(client, i, MP2949A_MFR_VR_CONFIG);
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * Rail A bit 5, Rail B bit 4, Rail C bit 3.
> + * 1'b1: 5mV (vr12/imvp8)
> + * 1'b0: 10mv (imvp9)
> + */
> + info->vrm_version[i] = (ret & BIT(5 - i)) ? vr12 : imvp9;
> + }
> +
> + return 0;
> +}
> +
> +static struct pmbus_driver_info mp2949a_info = {
> + .pages = MP2949A_PAGE_NUM,
> + .format[PSC_VOLTAGE_IN] = linear,
> + .format[PSC_VOLTAGE_OUT] = vid,
> + .format[PSC_CURRENT_OUT] = linear,
> + .format[PSC_TEMPERATURE] = linear,
> + .format[PSC_POWER] = direct,
> + .m[PSC_POWER] = 1,
> + .b[PSC_POWER] = 0,
> + .R[PSC_POWER] = 0,
> + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
> + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> + PMBUS_HAVE_TEMP | PMBUS_HAVE_POUT,
> + .func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
> + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> + PMBUS_HAVE_POUT,
> + .func[2] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
> + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> + PMBUS_HAVE_POUT,
> + .identify = mp2949a_identify,
> + .read_byte_data = mp2949a_read_byte_data,
> + .read_word_data = mp2949a_read_word_data,
> +};
> +
> +static int mp2949a_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct pmbus_driver_info *info;
> +
> + info = devm_kmemdup(&client->dev, &mp2949a_info, sizeof(*info),
> + GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + return pmbus_do_probe(client, info);
> +}
> +
> +static const struct i2c_device_id mp2949a_id[] = {
> + {"mp2949a", 0},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, mp2949a_id);
> +
> +static const struct of_device_id mp2949a_of_match[] = {
> + {.compatible = "mps,mp2949a"},
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, mp2949a_of_match);
> +
> +static struct i2c_driver mp2949a_driver = {
> + .driver = {
> + .name = "mp2949a",
> + .of_match_table = of_match_ptr(mp2949a_of_match),
> + },
> + .probe = mp2949a_probe,
> + .id_table = mp2949a_id,
> +};
> +
> +module_i2c_driver(mp2949a_driver);
> +
> +MODULE_AUTHOR("Ainux <ainux.wang@gmail.com>");
> +MODULE_DESCRIPTION("PMBus driver for Monolithic Power Systems MP2949A");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS(PMBUS);
>