Re: [PATCH v3 1/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring driver
On Mon, Nov 23, 2020 at 05:16:41AM -0800, Guenter Roeck wrote: > On Sun, Nov 22, 2020 at 11:54:49PM -0800, Tao Ren wrote: > > On Sun, Nov 22, 2020 at 10:33:42AM -0800, Guenter Roeck wrote: > > > On Thu, Nov 19, 2020 at 09:53:23AM -0800, rentao.b...@gmail.com wrote: > > > > From: Tao Ren > > > > > > > > Add hardware monitoring driver for the Maxim MAX127 chip. > > > > > > > > MAX127 min/max range handling code is inspired by the max197 driver. > > > > > > > > Signed-off-by: Tao Ren > > > > > > Nice cleanup. Couple of minor comments. > > > > > > Thanks, > > > Guenter > > > > > > > --- > > > > Changes in v3: > > > >- no code change. xdp maintainers were removed from to/cc list. > > > > Changes in v2: > > > >- replace devm_hwmon_device_register_with_groups() with > > > > devm_hwmon_device_register_with_info() API. > > > >- divide min/max read and write methods to separate functions. > > > >- fix raw-to-vin conversion logic. > > > >- refine ctrl_byte handling so mutex is not needed to protect the > > > > byte. > > > >- improve i2c_transfer() error handling. > > > >- a few other improvements (comments, variable naming, and etc.). > > > > > > > > drivers/hwmon/Kconfig | 9 ++ > > > > drivers/hwmon/Makefile | 1 + > > > > drivers/hwmon/max127.c | 346 + > > > > 3 files changed, 356 insertions(+) > > > > create mode 100644 drivers/hwmon/max127.c > > > > > > > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > > > > index 9d600e0c5584..716df51edc87 100644 > > > > --- a/drivers/hwmon/Kconfig > > > > +++ b/drivers/hwmon/Kconfig > > > > @@ -950,6 +950,15 @@ config SENSORS_MAX > > > > This driver can also be built as a module. If so, the module > > > > will be called max. > > > > > > > > +config SENSORS_MAX127 > > > > + tristate "Maxim MAX127 12-bit 8-channel Data Acquisition System" > > > > + depends on I2C > > > > + help > > > > + Say y here to support Maxim's MAX127 DAS chips. > > > > + > > > > + This driver can also be built as a module. If so, the module > > > > + will be called max127. > > > > + > > > > config SENSORS_MAX16065 > > > > tristate "Maxim MAX16065 System Manager and compatibles" > > > > depends on I2C > > > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > > > > index 1083bbfac779..01ca5d3fbad4 100644 > > > > --- a/drivers/hwmon/Makefile > > > > +++ b/drivers/hwmon/Makefile > > > > @@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o > > > > obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o > > > > obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o > > > > obj-$(CONFIG_SENSORS_MAX) += max.o > > > > +obj-$(CONFIG_SENSORS_MAX127) += max127.o > > > > obj-$(CONFIG_SENSORS_MAX16065) += max16065.o > > > > obj-$(CONFIG_SENSORS_MAX1619) += max1619.o > > > > obj-$(CONFIG_SENSORS_MAX1668) += max1668.o > > > > diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c > > > > new file mode 100644 > > > > index ..3df4c225a6a2 > > > > --- /dev/null > > > > +++ b/drivers/hwmon/max127.c > > > > @@ -0,0 +1,346 @@ > > > > +// SPDX-License-Identifier: GPL-2.0+ > > > > +/* > > > > + * Hardware monitoring driver for MAX127. > > > > + * > > > > + * Copyright (c) 2020 Facebook Inc. > > > > + */ > > > > + > > > > +#include > > > > +#include > > > > +#include > > > > > > Not needed. > > > > > > > +#include > > > > +#include > > > > +#include > > > > +#include > > > > > > Not needed. > > > > Thanks for pointing it out. Both includes are deleted in v4. > > > > > > > > > + > > > > +/* > > > > + * MAX127 Control Byte. Refer to MAX127 datasheet, Table 1 > > > > "Control-Byte > > > > + * Format" for details. > > > > + */ > > > > +#define MAX127_CTRL_START BIT(7) > > > > +#define MAX127_CTRL_SEL_SHIFT 4 > > > > +#define MAX127_CTRL_RNGBIT(3) > > > > +#define MAX127_CTRL_BIPBIT(2) > > > > +#define MAX127_CTRL_PD1BIT(1) > > > > +#define MAX127_CTRL_PD0BIT(0) > > > > + > > > > +#define MAX127_NUM_CHANNELS8 > > > > +#define MAX127_SET_CHANNEL(ch) (((ch) & 7) << MAX127_CTRL_SEL_SHIFT) > > > > + > > > > +/* > > > > + * MAX127 channel input ranges. Refer to MAX127 datasheet, Table 3 > > > > "Range > > > > + * and Polarity Selection" for details. > > > > + */ > > > > +#define MAX127_FULL_RANGE 1 /* 10V */ > > > > +#define MAX127_HALF_RANGE 5000/* 5V */ > > > > + > > > > +/* > > > > + * MAX127 returns 2 bytes at read: > > > > + * - the first byte contains data[11:4]. > > > > + * - the second byte contains data[3:0] (MSB) and 4 dummy 0s (LSB). > > > > + * Refer to MAX127 datasheet, "Read a Conversion (Read Cycle)" section > > > > + * for details. > > > > + */ > > > > +#define MAX127_DATA_LEN2 > > > > +#define MAX127_DATA_SHIFT 4 > > > > + > > > > +#define MAX1
Re: [PATCH v3 1/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring driver
On Sun, Nov 22, 2020 at 11:54:49PM -0800, Tao Ren wrote:
> On Sun, Nov 22, 2020 at 10:33:42AM -0800, Guenter Roeck wrote:
> > On Thu, Nov 19, 2020 at 09:53:23AM -0800, rentao.b...@gmail.com wrote:
> > > From: Tao Ren
> > >
> > > Add hardware monitoring driver for the Maxim MAX127 chip.
> > >
> > > MAX127 min/max range handling code is inspired by the max197 driver.
> > >
> > > Signed-off-by: Tao Ren
> >
> > Nice cleanup. Couple of minor comments.
> >
> > Thanks,
> > Guenter
> >
> > > ---
> > > Changes in v3:
> > >- no code change. xdp maintainers were removed from to/cc list.
> > > Changes in v2:
> > >- replace devm_hwmon_device_register_with_groups() with
> > > devm_hwmon_device_register_with_info() API.
> > >- divide min/max read and write methods to separate functions.
> > >- fix raw-to-vin conversion logic.
> > >- refine ctrl_byte handling so mutex is not needed to protect the
> > > byte.
> > >- improve i2c_transfer() error handling.
> > >- a few other improvements (comments, variable naming, and etc.).
> > >
> > > drivers/hwmon/Kconfig | 9 ++
> > > drivers/hwmon/Makefile | 1 +
> > > drivers/hwmon/max127.c | 346 +
> > > 3 files changed, 356 insertions(+)
> > > create mode 100644 drivers/hwmon/max127.c
> > >
> > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > > index 9d600e0c5584..716df51edc87 100644
> > > --- a/drivers/hwmon/Kconfig
> > > +++ b/drivers/hwmon/Kconfig
> > > @@ -950,6 +950,15 @@ config SENSORS_MAX
> > > This driver can also be built as a module. If so, the module
> > > will be called max.
> > >
> > > +config SENSORS_MAX127
> > > + tristate "Maxim MAX127 12-bit 8-channel Data Acquisition System"
> > > + depends on I2C
> > > + help
> > > + Say y here to support Maxim's MAX127 DAS chips.
> > > +
> > > + This driver can also be built as a module. If so, the module
> > > + will be called max127.
> > > +
> > > config SENSORS_MAX16065
> > > tristate "Maxim MAX16065 System Manager and compatibles"
> > > depends on I2C
> > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> > > index 1083bbfac779..01ca5d3fbad4 100644
> > > --- a/drivers/hwmon/Makefile
> > > +++ b/drivers/hwmon/Makefile
> > > @@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o
> > > obj-$(CONFIG_SENSORS_LTC4261)+= ltc4261.o
> > > obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
> > > obj-$(CONFIG_SENSORS_MAX)+= max.o
> > > +obj-$(CONFIG_SENSORS_MAX127) += max127.o
> > > obj-$(CONFIG_SENSORS_MAX16065) += max16065.o
> > > obj-$(CONFIG_SENSORS_MAX1619)+= max1619.o
> > > obj-$(CONFIG_SENSORS_MAX1668)+= max1668.o
> > > diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c
> > > new file mode 100644
> > > index ..3df4c225a6a2
> > > --- /dev/null
> > > +++ b/drivers/hwmon/max127.c
> > > @@ -0,0 +1,346 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +/*
> > > + * Hardware monitoring driver for MAX127.
> > > + *
> > > + * Copyright (c) 2020 Facebook Inc.
> > > + */
> > > +
> > > +#include
> > > +#include
> > > +#include
> >
> > Not needed.
> >
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> >
> > Not needed.
>
> Thanks for pointing it out. Both includes are deleted in v4.
>
> >
> > > +
> > > +/*
> > > + * MAX127 Control Byte. Refer to MAX127 datasheet, Table 1 "Control-Byte
> > > + * Format" for details.
> > > + */
> > > +#define MAX127_CTRL_STARTBIT(7)
> > > +#define MAX127_CTRL_SEL_SHIFT4
> > > +#define MAX127_CTRL_RNG BIT(3)
> > > +#define MAX127_CTRL_BIP BIT(2)
> > > +#define MAX127_CTRL_PD1 BIT(1)
> > > +#define MAX127_CTRL_PD0 BIT(0)
> > > +
> > > +#define MAX127_NUM_CHANNELS 8
> > > +#define MAX127_SET_CHANNEL(ch) (((ch) & 7) << MAX127_CTRL_SEL_SHIFT)
> > > +
> > > +/*
> > > + * MAX127 channel input ranges. Refer to MAX127 datasheet, Table 3 "Range
> > > + * and Polarity Selection" for details.
> > > + */
> > > +#define MAX127_FULL_RANGE1 /* 10V */
> > > +#define MAX127_HALF_RANGE5000/* 5V */
> > > +
> > > +/*
> > > + * MAX127 returns 2 bytes at read:
> > > + * - the first byte contains data[11:4].
> > > + * - the second byte contains data[3:0] (MSB) and 4 dummy 0s (LSB).
> > > + * Refer to MAX127 datasheet, "Read a Conversion (Read Cycle)" section
> > > + * for details.
> > > + */
> > > +#define MAX127_DATA_LEN 2
> > > +#define MAX127_DATA_SHIFT4
> > > +
> > > +#define MAX127_SIGN_BIT BIT(11)
> > > +
> > > +struct max127_data {
> > > + struct mutex lock;
> > > + struct i2c_client *client;
> > > + u8 ctrl_byte[MAX127_NUM_CHANNELS];
> > > +};
> > > +
> > > +static int max127_select_channel(struct i2c_client *client, u8 ctrl_byte)
> > > +{
> > > + int status;
> > > + struct i2c_msg msg = {
> > > + .addr = client->addr,
> > > + .flags = 0,
> > > +
Re: [PATCH v3 1/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring driver
On Sun, Nov 22, 2020 at 10:33:42AM -0800, Guenter Roeck wrote:
> On Thu, Nov 19, 2020 at 09:53:23AM -0800, rentao.b...@gmail.com wrote:
> > From: Tao Ren
> >
> > Add hardware monitoring driver for the Maxim MAX127 chip.
> >
> > MAX127 min/max range handling code is inspired by the max197 driver.
> >
> > Signed-off-by: Tao Ren
>
> Nice cleanup. Couple of minor comments.
>
> Thanks,
> Guenter
>
> > ---
> > Changes in v3:
> >- no code change. xdp maintainers were removed from to/cc list.
> > Changes in v2:
> >- replace devm_hwmon_device_register_with_groups() with
> > devm_hwmon_device_register_with_info() API.
> >- divide min/max read and write methods to separate functions.
> >- fix raw-to-vin conversion logic.
> >- refine ctrl_byte handling so mutex is not needed to protect the
> > byte.
> >- improve i2c_transfer() error handling.
> >- a few other improvements (comments, variable naming, and etc.).
> >
> > drivers/hwmon/Kconfig | 9 ++
> > drivers/hwmon/Makefile | 1 +
> > drivers/hwmon/max127.c | 346 +
> > 3 files changed, 356 insertions(+)
> > create mode 100644 drivers/hwmon/max127.c
> >
> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > index 9d600e0c5584..716df51edc87 100644
> > --- a/drivers/hwmon/Kconfig
> > +++ b/drivers/hwmon/Kconfig
> > @@ -950,6 +950,15 @@ config SENSORS_MAX
> > This driver can also be built as a module. If so, the module
> > will be called max.
> >
> > +config SENSORS_MAX127
> > + tristate "Maxim MAX127 12-bit 8-channel Data Acquisition System"
> > + depends on I2C
> > + help
> > + Say y here to support Maxim's MAX127 DAS chips.
> > +
> > + This driver can also be built as a module. If so, the module
> > + will be called max127.
> > +
> > config SENSORS_MAX16065
> > tristate "Maxim MAX16065 System Manager and compatibles"
> > depends on I2C
> > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> > index 1083bbfac779..01ca5d3fbad4 100644
> > --- a/drivers/hwmon/Makefile
> > +++ b/drivers/hwmon/Makefile
> > @@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o
> > obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o
> > obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
> > obj-$(CONFIG_SENSORS_MAX) += max.o
> > +obj-$(CONFIG_SENSORS_MAX127) += max127.o
> > obj-$(CONFIG_SENSORS_MAX16065) += max16065.o
> > obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
> > obj-$(CONFIG_SENSORS_MAX1668) += max1668.o
> > diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c
> > new file mode 100644
> > index ..3df4c225a6a2
> > --- /dev/null
> > +++ b/drivers/hwmon/max127.c
> > @@ -0,0 +1,346 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Hardware monitoring driver for MAX127.
> > + *
> > + * Copyright (c) 2020 Facebook Inc.
> > + */
> > +
> > +#include
> > +#include
> > +#include
>
> Not needed.
>
> > +#include
> > +#include
> > +#include
> > +#include
>
> Not needed.
Thanks for pointing it out. Both includes are deleted in v4.
>
> > +
> > +/*
> > + * MAX127 Control Byte. Refer to MAX127 datasheet, Table 1 "Control-Byte
> > + * Format" for details.
> > + */
> > +#define MAX127_CTRL_START BIT(7)
> > +#define MAX127_CTRL_SEL_SHIFT 4
> > +#define MAX127_CTRL_RNGBIT(3)
> > +#define MAX127_CTRL_BIPBIT(2)
> > +#define MAX127_CTRL_PD1BIT(1)
> > +#define MAX127_CTRL_PD0BIT(0)
> > +
> > +#define MAX127_NUM_CHANNELS8
> > +#define MAX127_SET_CHANNEL(ch) (((ch) & 7) << MAX127_CTRL_SEL_SHIFT)
> > +
> > +/*
> > + * MAX127 channel input ranges. Refer to MAX127 datasheet, Table 3 "Range
> > + * and Polarity Selection" for details.
> > + */
> > +#define MAX127_FULL_RANGE 1 /* 10V */
> > +#define MAX127_HALF_RANGE 5000/* 5V */
> > +
> > +/*
> > + * MAX127 returns 2 bytes at read:
> > + * - the first byte contains data[11:4].
> > + * - the second byte contains data[3:0] (MSB) and 4 dummy 0s (LSB).
> > + * Refer to MAX127 datasheet, "Read a Conversion (Read Cycle)" section
> > + * for details.
> > + */
> > +#define MAX127_DATA_LEN2
> > +#define MAX127_DATA_SHIFT 4
> > +
> > +#define MAX127_SIGN_BITBIT(11)
> > +
> > +struct max127_data {
> > + struct mutex lock;
> > + struct i2c_client *client;
> > + u8 ctrl_byte[MAX127_NUM_CHANNELS];
> > +};
> > +
> > +static int max127_select_channel(struct i2c_client *client, u8 ctrl_byte)
> > +{
> > + int status;
> > + struct i2c_msg msg = {
> > + .addr = client->addr,
> > + .flags = 0,
> > + .len = sizeof(ctrl_byte),
> > + .buf = &ctrl_byte,
> > + };
> > +
> > + status = i2c_transfer(client->adapter, &msg, 1);
> > + if (status < 0)
> > + return status;
> > + else if (status != 1)
>
> else after return is not needed.
>
> > + return -EIO;
> > +
Re: [PATCH v3 1/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring driver
On Thu, Nov 19, 2020 at 09:53:23AM -0800, rentao.b...@gmail.com wrote:
> From: Tao Ren
>
> Add hardware monitoring driver for the Maxim MAX127 chip.
>
> MAX127 min/max range handling code is inspired by the max197 driver.
>
> Signed-off-by: Tao Ren
Nice cleanup. Couple of minor comments.
Thanks,
Guenter
> ---
> Changes in v3:
>- no code change. xdp maintainers were removed from to/cc list.
> Changes in v2:
>- replace devm_hwmon_device_register_with_groups() with
> devm_hwmon_device_register_with_info() API.
>- divide min/max read and write methods to separate functions.
>- fix raw-to-vin conversion logic.
>- refine ctrl_byte handling so mutex is not needed to protect the
> byte.
>- improve i2c_transfer() error handling.
>- a few other improvements (comments, variable naming, and etc.).
>
> drivers/hwmon/Kconfig | 9 ++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/max127.c | 346 +
> 3 files changed, 356 insertions(+)
> create mode 100644 drivers/hwmon/max127.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 9d600e0c5584..716df51edc87 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -950,6 +950,15 @@ config SENSORS_MAX
> This driver can also be built as a module. If so, the module
> will be called max.
>
> +config SENSORS_MAX127
> + tristate "Maxim MAX127 12-bit 8-channel Data Acquisition System"
> + depends on I2C
> + help
> + Say y here to support Maxim's MAX127 DAS chips.
> +
> + This driver can also be built as a module. If so, the module
> + will be called max127.
> +
> config SENSORS_MAX16065
> tristate "Maxim MAX16065 System Manager and compatibles"
> depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 1083bbfac779..01ca5d3fbad4 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o
> obj-$(CONFIG_SENSORS_LTC4261)+= ltc4261.o
> obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
> obj-$(CONFIG_SENSORS_MAX)+= max.o
> +obj-$(CONFIG_SENSORS_MAX127) += max127.o
> obj-$(CONFIG_SENSORS_MAX16065) += max16065.o
> obj-$(CONFIG_SENSORS_MAX1619)+= max1619.o
> obj-$(CONFIG_SENSORS_MAX1668)+= max1668.o
> diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c
> new file mode 100644
> index ..3df4c225a6a2
> --- /dev/null
> +++ b/drivers/hwmon/max127.c
> @@ -0,0 +1,346 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Hardware monitoring driver for MAX127.
> + *
> + * Copyright (c) 2020 Facebook Inc.
> + */
> +
> +#include
> +#include
> +#include
Not needed.
> +#include
> +#include
> +#include
> +#include
Not needed.
> +
> +/*
> + * MAX127 Control Byte. Refer to MAX127 datasheet, Table 1 "Control-Byte
> + * Format" for details.
> + */
> +#define MAX127_CTRL_STARTBIT(7)
> +#define MAX127_CTRL_SEL_SHIFT4
> +#define MAX127_CTRL_RNG BIT(3)
> +#define MAX127_CTRL_BIP BIT(2)
> +#define MAX127_CTRL_PD1 BIT(1)
> +#define MAX127_CTRL_PD0 BIT(0)
> +
> +#define MAX127_NUM_CHANNELS 8
> +#define MAX127_SET_CHANNEL(ch) (((ch) & 7) << MAX127_CTRL_SEL_SHIFT)
> +
> +/*
> + * MAX127 channel input ranges. Refer to MAX127 datasheet, Table 3 "Range
> + * and Polarity Selection" for details.
> + */
> +#define MAX127_FULL_RANGE1 /* 10V */
> +#define MAX127_HALF_RANGE5000/* 5V */
> +
> +/*
> + * MAX127 returns 2 bytes at read:
> + * - the first byte contains data[11:4].
> + * - the second byte contains data[3:0] (MSB) and 4 dummy 0s (LSB).
> + * Refer to MAX127 datasheet, "Read a Conversion (Read Cycle)" section
> + * for details.
> + */
> +#define MAX127_DATA_LEN 2
> +#define MAX127_DATA_SHIFT4
> +
> +#define MAX127_SIGN_BIT BIT(11)
> +
> +struct max127_data {
> + struct mutex lock;
> + struct i2c_client *client;
> + u8 ctrl_byte[MAX127_NUM_CHANNELS];
> +};
> +
> +static int max127_select_channel(struct i2c_client *client, u8 ctrl_byte)
> +{
> + int status;
> + struct i2c_msg msg = {
> + .addr = client->addr,
> + .flags = 0,
> + .len = sizeof(ctrl_byte),
> + .buf = &ctrl_byte,
> + };
> +
> + status = i2c_transfer(client->adapter, &msg, 1);
> + if (status < 0)
> + return status;
> + else if (status != 1)
else after return is not needed.
> + return -EIO;
> +
> + return 0;
> +}
> +
> +static int max127_read_channel(struct i2c_client *client, long *val)
> +{
> + int status;
> + u8 i2c_data[MAX127_DATA_LEN];
> + struct i2c_msg msg = {
> + .addr = client->addr,
> + .flags = I2C_M_RD,
> + .len = sizeof(i2c_data),
> + .buf = i2c_data,
> + };
[PATCH v3 1/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring driver
From: Tao Ren
Add hardware monitoring driver for the Maxim MAX127 chip.
MAX127 min/max range handling code is inspired by the max197 driver.
Signed-off-by: Tao Ren
---
Changes in v3:
- no code change. xdp maintainers were removed from to/cc list.
Changes in v2:
- replace devm_hwmon_device_register_with_groups() with
devm_hwmon_device_register_with_info() API.
- divide min/max read and write methods to separate functions.
- fix raw-to-vin conversion logic.
- refine ctrl_byte handling so mutex is not needed to protect the
byte.
- improve i2c_transfer() error handling.
- a few other improvements (comments, variable naming, and etc.).
drivers/hwmon/Kconfig | 9 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/max127.c | 346 +
3 files changed, 356 insertions(+)
create mode 100644 drivers/hwmon/max127.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 9d600e0c5584..716df51edc87 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -950,6 +950,15 @@ config SENSORS_MAX
This driver can also be built as a module. If so, the module
will be called max.
+config SENSORS_MAX127
+ tristate "Maxim MAX127 12-bit 8-channel Data Acquisition System"
+ depends on I2C
+ help
+ Say y here to support Maxim's MAX127 DAS chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called max127.
+
config SENSORS_MAX16065
tristate "Maxim MAX16065 System Manager and compatibles"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 1083bbfac779..01ca5d3fbad4 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o
obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o
obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
obj-$(CONFIG_SENSORS_MAX) += max.o
+obj-$(CONFIG_SENSORS_MAX127) += max127.o
obj-$(CONFIG_SENSORS_MAX16065) += max16065.o
obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
obj-$(CONFIG_SENSORS_MAX1668) += max1668.o
diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c
new file mode 100644
index ..3df4c225a6a2
--- /dev/null
+++ b/drivers/hwmon/max127.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for MAX127.
+ *
+ * Copyright (c) 2020 Facebook Inc.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+/*
+ * MAX127 Control Byte. Refer to MAX127 datasheet, Table 1 "Control-Byte
+ * Format" for details.
+ */
+#define MAX127_CTRL_START BIT(7)
+#define MAX127_CTRL_SEL_SHIFT 4
+#define MAX127_CTRL_RNGBIT(3)
+#define MAX127_CTRL_BIPBIT(2)
+#define MAX127_CTRL_PD1BIT(1)
+#define MAX127_CTRL_PD0BIT(0)
+
+#define MAX127_NUM_CHANNELS8
+#define MAX127_SET_CHANNEL(ch) (((ch) & 7) << MAX127_CTRL_SEL_SHIFT)
+
+/*
+ * MAX127 channel input ranges. Refer to MAX127 datasheet, Table 3 "Range
+ * and Polarity Selection" for details.
+ */
+#define MAX127_FULL_RANGE 1 /* 10V */
+#define MAX127_HALF_RANGE 5000/* 5V */
+
+/*
+ * MAX127 returns 2 bytes at read:
+ * - the first byte contains data[11:4].
+ * - the second byte contains data[3:0] (MSB) and 4 dummy 0s (LSB).
+ * Refer to MAX127 datasheet, "Read a Conversion (Read Cycle)" section
+ * for details.
+ */
+#define MAX127_DATA_LEN2
+#define MAX127_DATA_SHIFT 4
+
+#define MAX127_SIGN_BITBIT(11)
+
+struct max127_data {
+ struct mutex lock;
+ struct i2c_client *client;
+ u8 ctrl_byte[MAX127_NUM_CHANNELS];
+};
+
+static int max127_select_channel(struct i2c_client *client, u8 ctrl_byte)
+{
+ int status;
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = 0,
+ .len = sizeof(ctrl_byte),
+ .buf = &ctrl_byte,
+ };
+
+ status = i2c_transfer(client->adapter, &msg, 1);
+ if (status < 0)
+ return status;
+ else if (status != 1)
+ return -EIO;
+
+ return 0;
+}
+
+static int max127_read_channel(struct i2c_client *client, long *val)
+{
+ int status;
+ u8 i2c_data[MAX127_DATA_LEN];
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = sizeof(i2c_data),
+ .buf = i2c_data,
+ };
+
+ status = i2c_transfer(client->adapter, &msg, 1);
+ if (status < 0)
+ return status;
+ else if (status != 1)
+ return -EIO;
+
+ *val = (i2c_data[1] >> MAX127_DATA_SHIFT) |
+ ((u16)i2c_data[0] << MAX127_DATA_SHIFT);
+ return 0;
+}
+
+static long max127_process_raw(u8 ctrl_byte, long raw)
+{
+ long scale, weight;
+
+ /*
+* MAX127's data cod
