On Thu, Jun 17, 2021 at 05:43:23PM +0800, ainux.wang@xxxxxxxxx wrote:
> From: "Ainux.Wang" <ainux.wang@xxxxxxxxx>
>
> Add support for MP2949A device from Monolithic Power Systems, Inc. (MPS)
> vendor. 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 with only one DAC for each rail to generate REF.
>
> Signed-off-by: Ainux.Wang <ainux.wang@xxxxxxxxx>
> ---
> Documentation/hwmon/mp2949a.rst | 48 ++++++++++++++++++
Reference needs to be added to Documentation/hwmon/index.rst.
> drivers/hwmon/pmbus/Kconfig | 9 ++++
> drivers/hwmon/pmbus/Makefile | 1 +
> drivers/hwmon/pmbus/mp2949a.c | 83 ++++++++++++++++++++++++++++++++
> drivers/hwmon/pmbus/pmbus.h | 6 +++
> drivers/hwmon/pmbus/pmbus_core.c | 18 +++++--
Changes to the PMBus core need to be submitted as separate patches.
> 6 files changed, 160 insertions(+), 5 deletions(-)
> create mode 100644 Documentation/hwmon/mp2949a.rst
> create mode 100644 drivers/hwmon/pmbus/mp2949a.c
>
> diff --git a/Documentation/hwmon/mp2949a.rst b/Documentation/hwmon/mp2949a.rst
> new file mode 100644
> index 000000000000..82ab15e0588b
> --- /dev/null
> +++ b/Documentation/hwmon/mp2949a.rst
> @@ -0,0 +1,48 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +Kernel driver mp2949a
> +====================
> +
> +Supported chips:
> +
> + * MPS MP2949A
> +
> + Prefix: 'mp2949a'
> +
> +Author:
> +
> + Ainux Wang <ainux.wang@xxxxxxxxx>
> +
> +Description
> +-----------
> +
> +This driver implements support for Monolithic Power Systems, Inc. (MPS)
> +vendor triple-loop, digital, multi-phase controller MP2949A.
drop 'vendor'
> +
> +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 with only one DAC for each rail to generate REF.
> +
> +Device supports:
> +
> +- SVID interface.
> +- PMBus interface.
> +
> +Device complaint with:
compliant
> +
> +- PMBus rev 1.2 interface.
> +
> +Device supports direct format for reading output power.
> +Device supports linear format for reading input voltage and 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 37a5c39784fa..b1344b265976 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -248,6 +248,15 @@ 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_MP2975
> tristate "MPS MP2975"
> help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index f8dcc27cd56a..bfb55ab12da1 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -28,6 +28,7 @@ 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_MP2975) += mp2975.o
> obj-$(CONFIG_SENSORS_PM6764TR) += pm6764tr.o
> obj-$(CONFIG_SENSORS_PXE1610) += pxe1610.o
> diff --git a/drivers/hwmon/pmbus/mp2949a.c b/drivers/hwmon/pmbus/mp2949a.c
> new file mode 100644
> index 000000000000..2b51176d8921
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/mp2949a.c
> @@ -0,0 +1,83 @@
> +// 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@xxxxxxxxx>
> + */
> +
> +#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
> +
> +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,
> + .skip_icp = true,
We already have a means to specify device specific flags
(pmbus_platform_data). Please use it when needed.
> +};
> +
> +static int mp2949a_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct pmbus_driver_info *info;
> + int i;
> +
> + info = devm_kmemdup(&client->dev, &mp2949a_info, sizeof(*info),
> + GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + for (i = 0; i < MP2949A_PAGE_NUM; i++)
> + info->vrm_version[i] = vr12;
The chip supports both 5mv step size (vr12/imvp8) and 10mv step size
(imvp9). This suggests that the driver should identify the mode
dynamically using the identify callback and set vrm_version based
on MFR_VR_CONFIG bit 5.
> +
> + 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@xxxxxxxxx>");
> +MODULE_DESCRIPTION("PMBus driver for Monolithic Power Systems MP2949A");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
> index 3968924f8533..fd329670876d 100644
> --- a/drivers/hwmon/pmbus/pmbus.h
> +++ b/drivers/hwmon/pmbus/pmbus.h
> @@ -454,6 +454,12 @@ struct pmbus_driver_info {
>
> /* custom attributes */
> const struct attribute_group **groups;
> +
> + /*
> + * Skip identify chip parameters,
> + * some device do not support the PMBUS_VOUT_MODE.
> + */
> + bool skip_icp;
> };
>
> /* Regulator ops */
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index bbd745178147..644bef5cdafd 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -2248,13 +2248,21 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
> return -ENODEV;
> }
>
> - for (page = 0; page < info->pages; page++) {
> - ret = pmbus_identify_common(client, data, page);
> - if (ret < 0) {
> - dev_err(dev, "Failed to identify chip capabilities\n");
> - return ret;
> + /*
> + * Some device do not support the PMBUS_VOUT_MODE,
> + * and the driver of device has known correct formats,
> + * so the driver set skip_icp to true.
> + */
The existing code should not affect device behavior. A failure to read
PMBUS_VOUT_MODE does not result in an error. As such, there is no reason
to add this flag. The only reason to add such a flag would be that the chip
returns bad data when reading PMBUS_VOUT_MODE. However, even that could
be (and is) handled by implementing a custom read_byte_data function to
catch the read and return the expected value(s). This would be a possible
alternative to using the identify callback if the chip does not return
an error when reading PMBUS_VOUT_MODE.
Guenter
