On Thu, 24 Jun 2021 at 21:17, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On Wed, Jun 23, 2021 at 08:54:26AM +0800, ainux.wang@xxxxxxxxx wrote:
> > From: "Ainux.Wang" <ainux.wang@xxxxxxxxx>
> >
> > 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@xxxxxxxxx>
> > ---
> > v5:
> > - Moved change log to right here.
> > v4:
> > - Removed mp2949a_read_byte_data().
>
> Your other question left me confused. I had previously asked to provide
> a rationale for filtering out the PMBUS_VOUT_MODE command, and I had
> stated that "the chip does not support it" is not a valid reason. However,
> "the chip does not support it but does not report an error when reading
> it" _is_ a valid reason. So what happens when the PMBus core reads
> PMBUS_VOUT_MODE ? Does the chip return an error, or some random data ?
>
> Thanks,
> Guenter
>
Hi, Guenter
I have not been clear about the cause of this problem that
"the chip does not support it is not a valid reason".
However, i have added some "printk", i found the chip will return some
random data,
when the PMbus core reads PMBUS_STATUS and PMBUS_VOUT_MODE.
So, I do not known what should i do, when the PMbus core reads PMBUS_STATUS.
and i have knwon that use "This chip do not support the VOUT_MODE command,
the chip does not support it but return some random data when reading
" instead of
"
/*
* This chip do not support the VOUT_MODE command.
* There is not VOUT_MODE command in MP2949A datasheet P29~P31.
* So this is EINVAL in here.
*/
"
Now, there is only one question left, what should the PMbus do, the
chip return random data,
when it reads PMBUS_STATUS by i2c_smbus_read_word_data() or
i2c_smbus_read_byte_data()?
Can the PMbus core use pmbus_read_status_byte() and
pmbus_read_status_word() instead of
i2c_smbus_read_byte_data() and i2c_smbus_read_word_data() ?
Best regards,
Ainux Wang.
> > - Added space before and after '-' and fixed a bug that is '~' on line 35.
> >
> > v3:
> > - Added change log here.
> > - Errors in the document have been modified.
> > - Fixed PMBUS_VOUT_MODE to MP2949A_MFR_VR_CONFIG.
> > - Removed unnecessary vout_params and empty line.
> >
> > v2:
> > - Reference has been added to Documentation/hwmon/index.rst.
> > - Droped 'vendor'.
> > - Removed change codes of the PMBus core and added mp2949a_identify()
> > and mp2949a_read_byte_data() to this driver.
> >
> > v1:
> > - Add support for MPS MP2949A.
> > 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 | 102 ++++++++++++++++++++++++++++++++
> > 5 files changed, 157 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 9ed60fa84cbe..56aac3b1678d 100644
> > --- a/Documentation/hwmon/index.rst
> > +++ b/Documentation/hwmon/index.rst
> > @@ -137,6 +137,7 @@ Hardware Monitoring Kernel Drivers
> > mcp3021
> > menf21bmc
> > mlxreg-fan
> > + mp2949a
> > mp2975
> > nct6683
> > nct6775
> > 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@xxxxxxxxx>
> > +
> > +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 rails.
> > +- 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 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..d1f36c008e58
> > --- /dev/null
> > +++ b/drivers/hwmon/pmbus/mp2949a.c
> > @@ -0,0 +1,102 @@
> > +// 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
> > +
> > +#define MP2949A_MFR_VR_CONFIG 0xE4
> > +
> > +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,
> > +};
> > +
> > +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@xxxxxxxxx>");
> > +MODULE_DESCRIPTION("PMBus driver for Monolithic Power Systems MP2949A");
> > +MODULE_LICENSE("GPL");
