[PATCH v4 0/4] Introduce MEN 14F021P BMC driver series

[PATCH v4 0/4] Introduce MEN 14F021P BMC driver series

[Andreas Werner]

This patch set add support for the MEN 14F021P00 Board Management called BMC.

The BMC is a PIC Mikrocontroller which assembled on almost all of our
3U Compact PCI CPU board and a few Box PCs.
main part of the BMC is to start and monitor the board, but there are a
lot more features which can be accessed using an I2C Host interface

Features supported in this Patchset:
        - Watchdog
        - LEDs
	- HWMON

The Patchset includes a MFD Core driver, Watchdog, hwmon  and LEDs driver.

Changes in v4:
	- fixed some style issues
	- fixed GPL license version
	- added hwmon voltage monitoring slave driver

Changes in v3:
        - deleted i2c_smbus wrapper functions and use native one
        - some cosmentics and variable renaming to be more clear
        - renamed "leave production" mode to "exit production mode"

Changes in v2:
        - changed i2c_smbus_read wrapper function to return both, value
          and error.
        - moved "leave production mode" from Watchdog driver to mfd core.
        - fixed some return values in the watchdog driver to return the original
          error value instead of -EIO.


Andreas Werner (4):
  drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver
  drivers/watchdog/menf21bmc_wdt: introduce MEN 14F021P00 BMC Watchdog
    driver
  drivers/leds/leds-menf21bmc: introduce MEN 14F021P00 BMC LED driver
  drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

 drivers/hwmon/Kconfig            |   7 ++
 drivers/hwmon/Makefile           |   1 +
 drivers/hwmon/menf21bmc_hwmon.c  | 238 +++++++++++++++++++++++++++++++++++++++
 drivers/leds/Kconfig             |   6 +
 drivers/leds/Makefile            |   1 +
 drivers/leds/leds-menf21bmc.c    | 131 +++++++++++++++++++++
 drivers/mfd/Kconfig              |  12 ++
 drivers/mfd/Makefile             |   1 +
 drivers/mfd/menf21bmc.c          | 132 ++++++++++++++++++++++
 drivers/watchdog/Kconfig         |   7 ++
 drivers/watchdog/Makefile        |   1 +
 drivers/watchdog/menf21bmc_wdt.c | 203 +++++++++++++++++++++++++++++++++
 12 files changed, 740 insertions(+)
 create mode 100644 drivers/hwmon/menf21bmc_hwmon.c
 create mode 100644 drivers/leds/leds-menf21bmc.c
 create mode 100644 drivers/mfd/menf21bmc.c
 create mode 100644 drivers/watchdog/menf21bmc_wdt.c

-- 
2.0.4

[PATCH v4 1/4] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver

[Andreas Werner]

The MEN 14F021P00 Board Management Controller provides an
I2C interface to the host to access the feature implemented in the BMC.
The BMC is a PIC Microntroller assembled on CPCI Card from MEN Mikroelektronik
and on a few Box/Display Computer.

Added MFD Core driver, supporting the I2C communication to the device.

The MFD driver currently supports the following features:
 	- Watchdog
 	- LEDs
	- Hwmon (voltage monitoring)

Signed-off-by: Andreas Werner <andreas.werner@men.de>
---
 drivers/mfd/Kconfig     |  12 +++++
 drivers/mfd/Makefile    |   1 +
 drivers/mfd/menf21bmc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 145 insertions(+)
 create mode 100644 drivers/mfd/menf21bmc.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b8d9ca0..bf155b9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -453,6 +453,18 @@ config MFD_MAX8998
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_MENF21BMC
+	tristate "MEN 14F021P00 Board Management Controller Support"
+	depends on I2C=y
+	select MFD_CORE
+	help
+	  Say yes here to add support for the MEN 14F021P00 BMC
+	  which is a Board Management Controller connected to the I2C bus.
+	  The device supports multiple sub-devices like LED, HWMON  and WDT.
+	  This driver provides common support for accessing the devices;
+	  additional drivers must be enabled in order to use the
+	  functionality of the BMC device.
+
 config EZX_PCAP
 	bool "Motorola EZXPCAP Support"
 	depends on SPI_MASTER
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 4e2bc25..37bf336 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -169,6 +169,7 @@ obj-$(CONFIG_MFD_AS3711)	+= as3711.o
 obj-$(CONFIG_MFD_AS3722)	+= as3722.o
 obj-$(CONFIG_MFD_STW481X)	+= stw481x.o
 obj-$(CONFIG_MFD_IPAQ_MICRO)	+= ipaq-micro.o
+obj-$(CONFIG_MFD_MENF21BMC)	+= menf21bmc.o
 
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
diff --git a/drivers/mfd/menf21bmc.c b/drivers/mfd/menf21bmc.c
new file mode 100644
index 0000000..a6eb03f
--- /dev/null
+++ b/drivers/mfd/menf21bmc.c
@@ -0,0 +1,132 @@
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+
+#define BMC_CMD_WDT_EXIT_PROD	0x18
+#define BMC_CMD_WDT_PROD_STAT	0x19
+#define BMC_CMD_REV_MAJOR	0x80
+#define BMC_CMD_REV_MINOR	0x81
+#define BMC_CMD_REV_MAIN	0x82
+
+static struct mfd_cell menf21bmc_cell[] = {
+	{ .name = "menf21bmc_wdt", },
+	{ .name = "menf21bmc_led", },
+	{ .name = "menf21bmc_hwmon", }
+};
+
+static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
+{
+	int val, ret;
+
+	val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
+	if (val < 0)
+		return val;
+
+	/*
+	 * Production mode should be not active after delivery of the Board.
+	 * To be sure we check it, inform the user and exit the mode
+	 * if active.
+	 */
+	if (val == 0x00) {
+		dev_info(&client->dev,
+			"BMC in production mode. Exit production mode\n");
+
+		ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int
+menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
+{
+	int ret;
+	int rev_major, rev_minor, rev_main;
+
+	ret = i2c_check_functionality(client->adapter,
+				      I2C_FUNC_SMBUS_BYTE_DATA |
+				      I2C_FUNC_SMBUS_WORD_DATA |
+				      I2C_FUNC_SMBUS_BYTE);
+	if (!ret)
+		return -ENODEV;
+
+	rev_major = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAJOR);
+	if (rev_major < 0) {
+		dev_err(&client->dev, "failed to get BMC major revision\n");
+		return rev_major;
+	}
+
+	rev_minor = i2c_smbus_read_word_data(client, BMC_CMD_REV_MINOR);
+	if (rev_minor < 0) {
+		dev_err(&client->dev, "failed to get BMC minor revision\n");
+		return rev_minor;
+	}
+
+	rev_main = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAIN);
+	if (rev_main < 0) {
+		dev_err(&client->dev, "failed to get BMC main revision\n");
+		return rev_main;
+	}
+
+	dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
+					rev_major, rev_minor, rev_main);
+
+	/*
+	 * We have to exit the Production Mode of the BMC to activate the
+	 * Watchdog functionality and the BIOS life sign monitoring.
+	 */
+	ret = menf21bmc_wdt_exit_prod_mode(client);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to leave production mode\n");
+		return ret;
+	}
+
+	ret = mfd_add_devices(&client->dev, 0, menf21bmc_cell,
+				ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to add BMC sub-devices\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int menf21bmc_remove(struct i2c_client *client)
+{
+	mfd_remove_devices(&client->dev);
+	return 0;
+}
+
+static const struct i2c_device_id menf21bmc_id_table[] = {
+	{ "menf21bmc", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
+
+static struct i2c_driver menf21bmc_driver = {
+	.driver.name	= "menf21bmc",
+	.id_table	= menf21bmc_id_table,
+	.probe		= menf21bmc_probe,
+	.remove		= menf21bmc_remove,
+};
+
+module_i2c_driver(menf21bmc_driver);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");
-- 
2.0.4

Re: [PATCH v4 1/4] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver

[Lee Jones]

On Wed, 13 Aug 2014, Andreas Werner wrote:
> The MEN 14F021P00 Board Management Controller provides an
> I2C interface to the host to access the feature implemented in the BMC.
> The BMC is a PIC Microntroller assembled on CPCI Card from MEN Mikroelektronik
> and on a few Box/Display Computer.
> 
> Added MFD Core driver, supporting the I2C communication to the device.
> 
> The MFD driver currently supports the following features:
>  	- Watchdog
>  	- LEDs
> 	- Hwmon (voltage monitoring)
> 
> Signed-off-by: Andreas Werner <andreas.werner@men.de>
> ---
>  drivers/mfd/Kconfig     |  12 +++++
>  drivers/mfd/Makefile    |   1 +
>  drivers/mfd/menf21bmc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 145 insertions(+)
>  create mode 100644 drivers/mfd/menf21bmc.c
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b8d9ca0..bf155b9 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -453,6 +453,18 @@ config MFD_MAX8998
>  	  additional drivers must be enabled in order to use the functionality
>  	  of the device.
>  
> +config MFD_MENF21BMC
> +	tristate "MEN 14F021P00 Board Management Controller Support"
> +	depends on I2C=y

Why must I2C be built-in?

> +	select MFD_CORE
> +	help
> +	  Say yes here to add support for the MEN 14F021P00 BMC
> +	  which is a Board Management Controller connected to the I2C bus.
> +	  The device supports multiple sub-devices like LED, HWMON  and WDT.
> +	  This driver provides common support for accessing the devices;
> +	  additional drivers must be enabled in order to use the
> +	  functionality of the BMC device.
> +

Apart from that the patch looks good to me.

I'm assuming this can go in via the MFD tree by itself?

Acked-by: Lee Jones <lee.jones@linaro.org>

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v4 1/4] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver

[Andreas Werner]

On Thu, Aug 21, 2014 at 12:30:46PM +0100, Lee Jones wrote:
> On Wed, 13 Aug 2014, Andreas Werner wrote:
> > The MEN 14F021P00 Board Management Controller provides an
> > I2C interface to the host to access the feature implemented in the BMC.
> > The BMC is a PIC Microntroller assembled on CPCI Card from MEN Mikroelektronik
> > and on a few Box/Display Computer.
> > 
> > Added MFD Core driver, supporting the I2C communication to the device.
> > 
> > The MFD driver currently supports the following features:
> >  	- Watchdog
> >  	- LEDs
> > 	- Hwmon (voltage monitoring)
> > 
> > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > ---
> >  drivers/mfd/Kconfig     |  12 +++++
> >  drivers/mfd/Makefile    |   1 +
> >  drivers/mfd/menf21bmc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 145 insertions(+)
> >  create mode 100644 drivers/mfd/menf21bmc.c
> > 
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index b8d9ca0..bf155b9 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -453,6 +453,18 @@ config MFD_MAX8998
> >  	  additional drivers must be enabled in order to use the functionality
> >  	  of the device.
> >  
> > +config MFD_MENF21BMC
> > +	tristate "MEN 14F021P00 Board Management Controller Support"
> > +	depends on I2C=y
> 
> Why must I2C be built-in?

Sorry my mistake, I2C must not be built in.

> 
> > +	select MFD_CORE
> > +	help
> > +	  Say yes here to add support for the MEN 14F021P00 BMC
> > +	  which is a Board Management Controller connected to the I2C bus.
> > +	  The device supports multiple sub-devices like LED, HWMON  and WDT.
> > +	  This driver provides common support for accessing the devices;
> > +	  additional drivers must be enabled in order to use the
> > +	  functionality of the BMC device.
> > +
> 
> Apart from that the patch looks good to me.
> 
> I'm assuming this can go in via the MFD tree by itself?

Yes why not.
Do you want to have a single patch for the MFD or
is it better to wait for the other Subsystem maintainer that I 
can resend a patch v5?


Regards
Andy

> 
> Acked-by: Lee Jones <lee.jones@linaro.org>
> 
> -- 
> Lee Jones
> Linaro STMicroelectronics Landing Team Lead
> Linaro.org │ Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v4 1/4] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver

[Lee Jones]

On Thu, 21 Aug 2014, Andreas Werner wrote:
> On Thu, Aug 21, 2014 at 12:30:46PM +0100, Lee Jones wrote:
> > On Wed, 13 Aug 2014, Andreas Werner wrote:
> > > The MEN 14F021P00 Board Management Controller provides an
> > > I2C interface to the host to access the feature implemented in the BMC.
> > > The BMC is a PIC Microntroller assembled on CPCI Card from MEN Mikroelektronik
> > > and on a few Box/Display Computer.
> > > 
> > > Added MFD Core driver, supporting the I2C communication to the device.
> > > 
> > > The MFD driver currently supports the following features:
> > >  	- Watchdog
> > >  	- LEDs
> > > 	- Hwmon (voltage monitoring)
> > > 
> > > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > > ---
> > >  drivers/mfd/Kconfig     |  12 +++++
> > >  drivers/mfd/Makefile    |   1 +
> > >  drivers/mfd/menf21bmc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 145 insertions(+)
> > >  create mode 100644 drivers/mfd/menf21bmc.c
> > > 
> > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > > index b8d9ca0..bf155b9 100644
> > > --- a/drivers/mfd/Kconfig
> > > +++ b/drivers/mfd/Kconfig
> > > @@ -453,6 +453,18 @@ config MFD_MAX8998
> > >  	  additional drivers must be enabled in order to use the functionality
> > >  	  of the device.
> > >  
> > > +config MFD_MENF21BMC
> > > +	tristate "MEN 14F021P00 Board Management Controller Support"
> > > +	depends on I2C=y
> > 
> > Why must I2C be built-in?
> 
> Sorry my mistake, I2C must not be built in.
> 
> > 
> > > +	select MFD_CORE
> > > +	help
> > > +	  Say yes here to add support for the MEN 14F021P00 BMC
> > > +	  which is a Board Management Controller connected to the I2C bus.
> > > +	  The device supports multiple sub-devices like LED, HWMON  and WDT.
> > > +	  This driver provides common support for accessing the devices;
> > > +	  additional drivers must be enabled in order to use the
> > > +	  functionality of the BMC device.
> > > +
> > 
> > Apart from that the patch looks good to me.
> > 
> > I'm assuming this can go in via the MFD tree by itself?
> 
> Yes why not.
> Do you want to have a single patch for the MFD or
> is it better to wait for the other Subsystem maintainer that I 
> can resend a patch v5?

When you resent, apply my Ack and I'll pick it up when the other
Maintainers are happy.

> > 
> > Acked-by: Lee Jones <lee.jones@linaro.org>
> > 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v4 2/4] drivers/watchdog/menf21bmc_wdt: introduce MEN 14F021P00 BMC Watchdog driver

[Andreas Werner]

Added driver to support the 14F021P00 BMC Watchdog.
The BMC is a Board Management Controller including watchdog functionality.

Signed-off-by: Andreas Werner <andreas.werner@men.de>
---
 drivers/watchdog/Kconfig         |   7 ++
 drivers/watchdog/Makefile        |   1 +
 drivers/watchdog/menf21bmc_wdt.c | 203 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 211 insertions(+)
 create mode 100644 drivers/watchdog/menf21bmc_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 76dd541..f96431d 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -95,6 +95,13 @@ config GPIO_WATCHDOG
 	  If you say yes here you get support for watchdog device
 	  controlled through GPIO-line.
 
+config MENF21BMC_WATCHDOG
+	tristate "MEN 14F021P00 BMC Watchdog"
+	depends on MFD_MENF21BMC
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC Watchdog.
+
 config WM831X_WATCHDOG
 	tristate "WM831x watchdog"
 	depends on MFD_WM831X
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 468c320..de17014 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -178,3 +178,4 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
+obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
diff --git a/drivers/watchdog/menf21bmc_wdt.c b/drivers/watchdog/menf21bmc_wdt.c
new file mode 100644
index 0000000..604824d
--- /dev/null
+++ b/drivers/watchdog/menf21bmc_wdt.c
@@ -0,0 +1,203 @@
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+#define DEVNAME "menf21bmc_wdt"
+
+#define BMC_CMD_WD_ON		0x11
+#define BMC_CMD_WD_OFF		0x12
+#define BMC_CMD_WD_TRIG		0x13
+#define BMC_CMD_WD_TIME		0x14
+#define BMC_CMD_WD_STATE	0x17
+#define BMC_WD_OFF_VAL		0x69
+#define BMC_CMD_RST_RSN		0x92
+
+#define BMC_WD_TIMEOUT_MIN	1	/* in sec */
+#define BMC_WD_TIMEOUT_MAX	6553	/* in sec */
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct menf21bmc_wdt {
+	struct watchdog_device wdt;
+	struct i2c_client *i2c_client;
+};
+
+static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
+{
+	int rst_rsn;
+
+	rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
+	if (rst_rsn < 0)
+		return rst_rsn;
+
+	if (rst_rsn == 0x02)
+		data->wdt.bootstatus |= WDIOF_CARDRESET;
+	else if (rst_rsn == 0x05)
+		data->wdt.bootstatus |= WDIOF_EXTERN1;
+	else if (rst_rsn == 0x06)
+		data->wdt.bootstatus |= WDIOF_EXTERN2;
+	else if (rst_rsn == 0x0A)
+		data->wdt.bootstatus |= WDIOF_POWERUNDER;
+
+	return 0;
+}
+
+static int menf21bmc_wdt_start(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
+}
+
+static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte_data(drv_data->i2c_client,
+					BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static int
+menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
+{
+	int ret;
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	/*
+	 *  BMC Watchdog does have a resolution of 100ms.
+	 *  Watchdog API defines the timeout in seconds, so we have to
+	 *  multiply the value.
+	 */
+	ret = i2c_smbus_write_word_data(drv_data->i2c_client,
+						BMC_CMD_WD_TIME, timeout * 10);
+	if (ret < 0)
+		return ret;
+
+	wdt->timeout = timeout;
+
+	return 0;
+}
+
+static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
+}
+
+static const struct watchdog_info menf21bmc_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = DEVNAME,
+};
+
+static const struct watchdog_ops menf21bmc_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= menf21bmc_wdt_start,
+	.stop		= menf21bmc_wdt_stop,
+	.ping		= menf21bmc_wdt_ping,
+	.set_timeout	= menf21bmc_wdt_settimeout,
+};
+
+static int menf21bmc_wdt_probe(struct platform_device *pdev)
+{
+	int ret, bmc_timeout;
+	struct menf21bmc_wdt *drv_data;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+
+	drv_data = devm_kzalloc(&pdev->dev,
+				sizeof(struct menf21bmc_wdt), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	drv_data->wdt.ops = &menf21bmc_wdt_ops;
+	drv_data->wdt.info = &menf21bmc_wdt_info;
+	drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
+	drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
+	drv_data->i2c_client = i2c_client;
+
+	/*
+	 * Get the current wdt timeout value from the BMC because
+	 * the BMC will save the value set before if the system restarts.
+	 */
+	bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
+							BMC_CMD_WD_TIME);
+	if (bmc_timeout < 0) {
+		dev_err(&pdev->dev, "failed to get current WDT timeout\n");
+		return bmc_timeout;
+	}
+
+	watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
+	watchdog_set_nowayout(&drv_data->wdt, nowayout);
+	watchdog_set_drvdata(&drv_data->wdt, drv_data);
+	platform_set_drvdata(pdev, drv_data);
+
+	ret = menf21bmc_wdt_set_bootstatus(drv_data);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
+		return ret;
+	}
+
+	ret = watchdog_register_device(&drv_data->wdt);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register Watchdog device\n");
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
+
+	return 0;
+}
+
+static int menf21bmc_wdt_remove(struct platform_device *pdev)
+{
+	struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+	dev_warn(&pdev->dev,
+		"Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
+
+	watchdog_unregister_device(&drv_data->wdt);
+
+	return 0;
+}
+
+static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
+{
+	struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+	i2c_smbus_write_word_data(drv_data->i2c_client,
+					BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static struct  platform_driver menf21bmc_wdt = {
+	.driver		= {
+		.owner = THIS_MODULE,
+		.name	= DEVNAME,
+	},
+	.probe		= menf21bmc_wdt_probe,
+	.remove		= menf21bmc_wdt_remove,
+	.shutdown	= menf21bmc_wdt_shutdown,
+};
+
+module_platform_driver(menf21bmc_wdt);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_wdt");
-- 
2.0.4

Re: [PATCH v4 2/4] drivers/watchdog/menf21bmc_wdt: introduce MEN 14F021P00 BMC Watchdog driver

[Guenter Roeck]

On Wed, Aug 13, 2014 at 10:39:59AM +0200, Andreas Werner wrote:
> Added driver to support the 14F021P00 BMC Watchdog.
> The BMC is a Board Management Controller including watchdog functionality.
> 
> Signed-off-by: Andreas Werner <andreas.werner@men.de>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

[PATCH v4 3/4] drivers/leds/leds-menf21bmc: introduce MEN 14F021P00 BMC LED driver

[Andreas Werner]

Added driver to support the 14F021P00 BMC LEDs.
The BMC is a Board Management Controller including four LEDs which
can be switched on and off.

Signed-off-by: Andreas Werner <andreas.werner@men.de>
---
 drivers/leds/Kconfig          |   6 ++
 drivers/leds/Makefile         |   1 +
 drivers/leds/leds-menf21bmc.c | 131 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 138 insertions(+)
 create mode 100644 drivers/leds/leds-menf21bmc.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 27cf0cd..d38ff3f 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -458,6 +458,12 @@ config LEDS_OT200
 	  This option enables support for the LEDs on the Bachmann OT200.
 	  Say Y to enable LEDs on the Bachmann OT200.
 
+config LEDS_MENF21BMC
+	tristate "LED support for the MEN 14F021P00 BMC"
+	depends on LEDS_CLASS && MFD_MENF21BMC
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC LEDs.
+
 comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
 
 config LEDS_BLINKM
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 3c03666..cadc433 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
 obj-$(CONFIG_LEDS_LM355x)		+= leds-lm355x.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
 obj-$(CONFIG_LEDS_VERSATILE)		+= leds-versatile.o
+obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
diff --git a/drivers/leds/leds-menf21bmc.c b/drivers/leds/leds-menf21bmc.c
new file mode 100644
index 0000000..4621f72
--- /dev/null
+++ b/drivers/leds/leds-menf21bmc.c
@@ -0,0 +1,131 @@
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
+ *
+ *  This is the core LED driver of the MEN 14F021P00 BMC.
+ *  There are four LEDs available which can be switched on and off.
+ *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/i2c.h>
+
+#define BMC_CMD_LED_GET_SET	0xA0
+#define BMC_BIT_LED_STATUS	BIT(0)
+#define BMC_BIT_LED_HOTSWAP	BIT(1)
+#define BMC_BIT_LED_USER1	BIT(2)
+#define BMC_BIT_LED_USER2	BIT(3)
+
+struct menf21bmc_led {
+	struct led_classdev cdev;
+	u8 led_bit;
+	const char *name;
+	struct i2c_client *i2c_client;
+};
+
+static struct menf21bmc_led leds[] = {
+	{
+		.name = "menf21bmc:led_status",
+		.led_bit = BMC_BIT_LED_STATUS,
+	},
+	{
+		.name = "menf21bmc:led_hotswap",
+		.led_bit = BMC_BIT_LED_HOTSWAP,
+	},
+	{
+		.name = "menf21bmc:led_user1",
+		.led_bit = BMC_BIT_LED_USER1,
+	},
+	{
+		.name = "menf21bmc:led_user2",
+		.led_bit = BMC_BIT_LED_USER2,
+	}
+};
+
+static DEFINE_MUTEX(led_lock);
+
+static void
+menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
+{
+	int led_val;
+	struct menf21bmc_led *led = container_of(led_cdev,
+					struct menf21bmc_led, cdev);
+
+	mutex_lock(&led_lock);
+	led_val = i2c_smbus_read_byte_data(led->i2c_client,
+						BMC_CMD_LED_GET_SET);
+	if (led_val < 0)
+		goto err_out;
+
+	if (value == LED_OFF)
+		led_val &= ~led->led_bit;
+	else
+		led_val |= led->led_bit;
+
+	i2c_smbus_write_byte_data(led->i2c_client,
+					BMC_CMD_LED_GET_SET, led_val);
+err_out:
+	mutex_unlock(&led_lock);
+}
+
+static int menf21bmc_led_probe(struct platform_device *pdev)
+{
+	int i;
+	int ret;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+
+	for (i = 0; i < ARRAY_SIZE(leds); i++) {
+		leds[i].cdev.name = leds[i].name;
+		leds[i].cdev.brightness_set = menf21bmc_led_set;
+		leds[i].i2c_client = i2c_client;
+		ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
+		if (ret < 0)
+			goto err_free_leds;
+	}
+	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
+
+	return 0;
+
+err_free_leds:
+	dev_err(&pdev->dev, "failed to register LED device\n");
+
+	for (i = i - 1; i >= 0; i--)
+		led_classdev_unregister(&leds[i].cdev);
+
+	return ret;
+}
+
+static int menf21bmc_led_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(leds); i++)
+		led_classdev_unregister(&leds[i].cdev);
+
+	return 0;
+}
+
+static struct platform_driver menf21bmc_led = {
+	.probe		= menf21bmc_led_probe,
+	.remove		= menf21bmc_led_remove,
+	.driver		= {
+		.name		= "menf21bmc_led",
+		.owner		= THIS_MODULE,
+	},
+};
+
+module_platform_driver(menf21bmc_led);
+
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_led");
-- 
2.0.4

Re: [PATCH v4 3/4] drivers/leds/leds-menf21bmc: introduce MEN 14F021P00 BMC LED driver

[Bryan Wu]

On Wed, Aug 13, 2014 at 1:40 AM, Andreas Werner <andreas.werner@men.de> wrote:
> Added driver to support the 14F021P00 BMC LEDs.
> The BMC is a Board Management Controller including four LEDs which
> can be switched on and off.
>
> Signed-off-by: Andreas Werner <andreas.werner@men.de>
> ---
>  drivers/leds/Kconfig          |   6 ++
>  drivers/leds/Makefile         |   1 +
>  drivers/leds/leds-menf21bmc.c | 131 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 138 insertions(+)
>  create mode 100644 drivers/leds/leds-menf21bmc.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 27cf0cd..d38ff3f 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -458,6 +458,12 @@ config LEDS_OT200
>           This option enables support for the LEDs on the Bachmann OT200.
>           Say Y to enable LEDs on the Bachmann OT200.
>
> +config LEDS_MENF21BMC
> +       tristate "LED support for the MEN 14F021P00 BMC"
> +       depends on LEDS_CLASS && MFD_MENF21BMC
> +       help
> +         Say Y here to include support for the MEN 14F021P00 BMC LEDs.
> +
>  comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
>
>  config LEDS_BLINKM
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 3c03666..cadc433 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_MAX8997)            += leds-max8997.o
>  obj-$(CONFIG_LEDS_LM355x)              += leds-lm355x.o
>  obj-$(CONFIG_LEDS_BLINKM)              += leds-blinkm.o
>  obj-$(CONFIG_LEDS_VERSATILE)           += leds-versatile.o
> +obj-$(CONFIG_LEDS_MENF21BMC)           += leds-menf21bmc.o
>
>  # LED SPI Drivers
>  obj-$(CONFIG_LEDS_DAC124S085)          += leds-dac124s085.o
> diff --git a/drivers/leds/leds-menf21bmc.c b/drivers/leds/leds-menf21bmc.c
> new file mode 100644
> index 0000000..4621f72
> --- /dev/null
> +++ b/drivers/leds/leds-menf21bmc.c
> @@ -0,0 +1,131 @@
> +/*
> + *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
> + *
> + *  This is the core LED driver of the MEN 14F021P00 BMC.
> + *  There are four LEDs available which can be switched on and off.
> + *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
> + *
> + *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
> + *
> + *  This program is free software; you can redistribute  it and/or modify it
> + *  under  the terms of  the GNU General  Public License as published by the
> + *  Free Software Foundation;  either version 2 of the  License, or (at your
> + *  option) any later version.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/leds.h>
> +#include <linux/i2c.h>
> +
> +#define BMC_CMD_LED_GET_SET    0xA0
> +#define BMC_BIT_LED_STATUS     BIT(0)
> +#define BMC_BIT_LED_HOTSWAP    BIT(1)
> +#define BMC_BIT_LED_USER1      BIT(2)
> +#define BMC_BIT_LED_USER2      BIT(3)
> +
> +struct menf21bmc_led {
> +       struct led_classdev cdev;
> +       u8 led_bit;
> +       const char *name;
> +       struct i2c_client *i2c_client;
> +};
> +
> +static struct menf21bmc_led leds[] = {
> +       {
> +               .name = "menf21bmc:led_status",
> +               .led_bit = BMC_BIT_LED_STATUS,
> +       },
> +       {
> +               .name = "menf21bmc:led_hotswap",
> +               .led_bit = BMC_BIT_LED_HOTSWAP,
> +       },
> +       {
> +               .name = "menf21bmc:led_user1",
> +               .led_bit = BMC_BIT_LED_USER1,
> +       },
> +       {
> +               .name = "menf21bmc:led_user2",
> +               .led_bit = BMC_BIT_LED_USER2,
> +       }
> +};
> +
> +static DEFINE_MUTEX(led_lock);
> +
> +static void
> +menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
> +{
> +       int led_val;
> +       struct menf21bmc_led *led = container_of(led_cdev,
> +                                       struct menf21bmc_led, cdev);
> +
> +       mutex_lock(&led_lock);
> +       led_val = i2c_smbus_read_byte_data(led->i2c_client,
> +                                               BMC_CMD_LED_GET_SET);
> +       if (led_val < 0)
> +               goto err_out;
> +
> +       if (value == LED_OFF)
> +               led_val &= ~led->led_bit;
> +       else
> +               led_val |= led->led_bit;
> +
> +       i2c_smbus_write_byte_data(led->i2c_client,
> +                                       BMC_CMD_LED_GET_SET, led_val);
> +err_out:
> +       mutex_unlock(&led_lock);
> +}
> +
> +static int menf21bmc_led_probe(struct platform_device *pdev)
> +{
> +       int i;
> +       int ret;
> +       struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
> +
> +       for (i = 0; i < ARRAY_SIZE(leds); i++) {
> +               leds[i].cdev.name = leds[i].name;
> +               leds[i].cdev.brightness_set = menf21bmc_led_set;
> +               leds[i].i2c_client = i2c_client;
> +               ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
> +               if (ret < 0)
> +                       goto err_free_leds;
> +       }
> +       dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
> +
> +       return 0;
> +
> +err_free_leds:
> +       dev_err(&pdev->dev, "failed to register LED device\n");
> +
> +       for (i = i - 1; i >= 0; i--)
> +               led_classdev_unregister(&leds[i].cdev);
> +
> +       return ret;
> +}
> +
> +static int menf21bmc_led_remove(struct platform_device *pdev)
> +{
> +       int i;
> +
> +       for (i = 0; i < ARRAY_SIZE(leds); i++)
> +               led_classdev_unregister(&leds[i].cdev);
> +
> +       return 0;
> +}
> +
> +static struct platform_driver menf21bmc_led = {
> +       .probe          = menf21bmc_led_probe,
> +       .remove         = menf21bmc_led_remove,
> +       .driver         = {
> +               .name           = "menf21bmc_led",
> +               .owner          = THIS_MODULE,
> +       },
> +};
> +

I still think this driver should be an I2C driver which is simply than
a platform driver.
Did I miss some discussion about this in our email?

Thanks,
-Bryan

> +module_platform_driver(menf21bmc_led);
> +
> +MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
> +MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:menf21bmc_led");
> --
> 2.0.4
>

Re: [PATCH v4 3/4] drivers/leds/leds-menf21bmc: introduce MEN 14F021P00 BMC LED driver

[Guenter Roeck]

On Mon, Aug 25, 2014 at 11:53:32AM -0700, Bryan Wu wrote:
> On Wed, Aug 13, 2014 at 1:40 AM, Andreas Werner <andreas.werner@men.de> wrote:
> > Added driver to support the 14F021P00 BMC LEDs.
> > The BMC is a Board Management Controller including four LEDs which
> > can be switched on and off.
> >
> > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > ---
> >  drivers/leds/Kconfig          |   6 ++
> >  drivers/leds/Makefile         |   1 +
> >  drivers/leds/leds-menf21bmc.c | 131 ++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 138 insertions(+)
> >  create mode 100644 drivers/leds/leds-menf21bmc.c
> >
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index 27cf0cd..d38ff3f 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -458,6 +458,12 @@ config LEDS_OT200
> >           This option enables support for the LEDs on the Bachmann OT200.
> >           Say Y to enable LEDs on the Bachmann OT200.
> >
> > +config LEDS_MENF21BMC
> > +       tristate "LED support for the MEN 14F021P00 BMC"
> > +       depends on LEDS_CLASS && MFD_MENF21BMC
> > +       help
> > +         Say Y here to include support for the MEN 14F021P00 BMC LEDs.
> > +
> >  comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
> >
> >  config LEDS_BLINKM
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> > index 3c03666..cadc433 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_MAX8997)            += leds-max8997.o
> >  obj-$(CONFIG_LEDS_LM355x)              += leds-lm355x.o
> >  obj-$(CONFIG_LEDS_BLINKM)              += leds-blinkm.o
> >  obj-$(CONFIG_LEDS_VERSATILE)           += leds-versatile.o
> > +obj-$(CONFIG_LEDS_MENF21BMC)           += leds-menf21bmc.o
> >
> >  # LED SPI Drivers
> >  obj-$(CONFIG_LEDS_DAC124S085)          += leds-dac124s085.o
> > diff --git a/drivers/leds/leds-menf21bmc.c b/drivers/leds/leds-menf21bmc.c
> > new file mode 100644
> > index 0000000..4621f72
> > --- /dev/null
> > +++ b/drivers/leds/leds-menf21bmc.c
> > @@ -0,0 +1,131 @@
> > +/*
> > + *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
> > + *
> > + *  This is the core LED driver of the MEN 14F021P00 BMC.
> > + *  There are four LEDs available which can be switched on and off.
> > + *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
> > + *
> > + *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
> > + *
> > + *  This program is free software; you can redistribute  it and/or modify it
> > + *  under  the terms of  the GNU General  Public License as published by the
> > + *  Free Software Foundation;  either version 2 of the  License, or (at your
> > + *  option) any later version.
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/leds.h>
> > +#include <linux/i2c.h>
> > +
> > +#define BMC_CMD_LED_GET_SET    0xA0
> > +#define BMC_BIT_LED_STATUS     BIT(0)
> > +#define BMC_BIT_LED_HOTSWAP    BIT(1)
> > +#define BMC_BIT_LED_USER1      BIT(2)
> > +#define BMC_BIT_LED_USER2      BIT(3)
> > +
> > +struct menf21bmc_led {
> > +       struct led_classdev cdev;
> > +       u8 led_bit;
> > +       const char *name;
> > +       struct i2c_client *i2c_client;
> > +};
> > +
> > +static struct menf21bmc_led leds[] = {
> > +       {
> > +               .name = "menf21bmc:led_status",
> > +               .led_bit = BMC_BIT_LED_STATUS,
> > +       },
> > +       {
> > +               .name = "menf21bmc:led_hotswap",
> > +               .led_bit = BMC_BIT_LED_HOTSWAP,
> > +       },
> > +       {
> > +               .name = "menf21bmc:led_user1",
> > +               .led_bit = BMC_BIT_LED_USER1,
> > +       },
> > +       {
> > +               .name = "menf21bmc:led_user2",
> > +               .led_bit = BMC_BIT_LED_USER2,
> > +       }
> > +};
> > +
> > +static DEFINE_MUTEX(led_lock);
> > +
> > +static void
> > +menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
> > +{
> > +       int led_val;
> > +       struct menf21bmc_led *led = container_of(led_cdev,
> > +                                       struct menf21bmc_led, cdev);
> > +
> > +       mutex_lock(&led_lock);
> > +       led_val = i2c_smbus_read_byte_data(led->i2c_client,
> > +                                               BMC_CMD_LED_GET_SET);
> > +       if (led_val < 0)
> > +               goto err_out;
> > +
> > +       if (value == LED_OFF)
> > +               led_val &= ~led->led_bit;
> > +       else
> > +               led_val |= led->led_bit;
> > +
> > +       i2c_smbus_write_byte_data(led->i2c_client,
> > +                                       BMC_CMD_LED_GET_SET, led_val);
> > +err_out:
> > +       mutex_unlock(&led_lock);
> > +}
> > +
> > +static int menf21bmc_led_probe(struct platform_device *pdev)
> > +{
> > +       int i;
> > +       int ret;
> > +       struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
> > +
> > +       for (i = 0; i < ARRAY_SIZE(leds); i++) {
> > +               leds[i].cdev.name = leds[i].name;
> > +               leds[i].cdev.brightness_set = menf21bmc_led_set;
> > +               leds[i].i2c_client = i2c_client;
> > +               ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
> > +               if (ret < 0)
> > +                       goto err_free_leds;
> > +       }
> > +       dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
> > +
> > +       return 0;
> > +
> > +err_free_leds:
> > +       dev_err(&pdev->dev, "failed to register LED device\n");
> > +
> > +       for (i = i - 1; i >= 0; i--)
> > +               led_classdev_unregister(&leds[i].cdev);
> > +
> > +       return ret;
> > +}
> > +
> > +static int menf21bmc_led_remove(struct platform_device *pdev)
> > +{
> > +       int i;
> > +
> > +       for (i = 0; i < ARRAY_SIZE(leds); i++)
> > +               led_classdev_unregister(&leds[i].cdev);
> > +
> > +       return 0;
> > +}
> > +
> > +static struct platform_driver menf21bmc_led = {
> > +       .probe          = menf21bmc_led_probe,
> > +       .remove         = menf21bmc_led_remove,
> > +       .driver         = {
> > +               .name           = "menf21bmc_led",
> > +               .owner          = THIS_MODULE,
> > +       },
> > +};
> > +
> 
> I still think this driver should be an I2C driver which is simply than
> a platform driver.
> Did I miss some discussion about this in our email?
> 
It is not possible to instantiate multiple drivers (watchdog, hwmon, led
in this case) with a single i2c chip.

Thanks,
Guenter

[PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Andreas Werner]

Added driver to support the 14F021P00 BMC Hardware Monitoring.
The BMC is a Board Management Controller including monitoring of the
board voltages.

Signed-off-by: Andreas Werner <andreas.werner@men.de>
---
 drivers/hwmon/Kconfig           |   7 ++
 drivers/hwmon/Makefile          |   1 +
 drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 246 insertions(+)
 create mode 100644 drivers/hwmon/menf21bmc_hwmon.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 37908ff..437c00f 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -828,6 +828,13 @@ config SENSORS_MCP3021
 	  This driver can also be built as a module.  If so, the module
 	  will be called mcp3021.
 
+config SENSORS_MENF21BMC_HWMON
+	tristate "MEN 14F021P00 BMC Hardware Monitoring"
+	depends on MFD_MENF21BMC && I2C
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC
+	  hardware monitoring.
+
 config SENSORS_ADCXX
 	tristate "National Semiconductor ADCxxxSxxx"
 	depends on SPI_MASTER
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 1362382..56ab872 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -114,6 +114,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
 obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
+obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
 obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
 obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
diff --git a/drivers/hwmon/menf21bmc_hwmon.c b/drivers/hwmon/menf21bmc_hwmon.c
new file mode 100644
index 0000000..ecb0ef1
--- /dev/null
+++ b/drivers/hwmon/menf21bmc_hwmon.c
@@ -0,0 +1,238 @@
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
+ *
+ *  This is the core hwmon driver of the MEN 14F021P00 BMC.
+ *  The BMC monitors the board voltages which can be access with this
+ *  driver through sysfs.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+
+#define DEVNAME "menf21bmc_hwmon"
+
+#define BMC_VOLT_COUNT	5
+#define MENF21BMC_V33	0
+#define MENF21BMC_V5	1
+#define MENF21BMC_V12	2
+#define MENF21BMC_V5_SB	3
+#define MENF21BMC_VBAT	4
+
+#define BMC_CMD_GET_NUM_VOLT 0x8E
+#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
+#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
+#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
+
+struct menf21bmc_hwmon {
+	char valid;
+	struct i2c_client *i2c_client;
+	unsigned long last_update;
+	u16 in_val[BMC_VOLT_COUNT];
+	u16 in_min[BMC_VOLT_COUNT];
+	u16 in_max[BMC_VOLT_COUNT];
+};
+
+static const char *const input_names[] = {
+	[MENF21BMC_V33]		= "MON_3,3V",
+	[MENF21BMC_V5]		= "MON_5V",
+	[MENF21BMC_V12]		= "MON_12V",
+	[MENF21BMC_V5_SB]	= "5V_STANDBY",
+	[MENF21BMC_VBAT]	= "VBAT"
+};
+
+static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
+{
+	int i;
+	uint16_t val;
+	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
+	struct menf21bmc_hwmon *data_ret = drv_data;
+
+	if (time_after(jiffies, drv_data->last_update + HZ) || !drv_data->valid) {
+		for (i = 0; i < BMC_VOLT_COUNT; i++) {
+			val = i2c_smbus_read_word_data(drv_data->i2c_client,
+						       IDX_TO_VOLT_INP_CMD(i));
+			if (val < 0)
+				goto abort;
+
+			drv_data->in_val[i] = val;
+		}
+		drv_data->last_update = jiffies;
+		drv_data->valid = 1;
+	}
+abort:
+	return data_ret;
+}
+
+static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
+{
+	int i;
+	uint16_t val;
+
+	for (i = 0; i < BMC_VOLT_COUNT; i++) {
+		val = i2c_smbus_read_word_data(drv_data->i2c_client,
+					       IDX_TO_VOLT_MIN_CMD(i));
+		if (val < 0)
+			return val;
+
+		drv_data->in_min[i] = val;
+
+		val = i2c_smbus_read_word_data(drv_data->i2c_client,
+					       IDX_TO_VOLT_MAX_CMD(i));
+		if (val < 0)
+			return val;
+
+		drv_data->in_max[i] = val;
+	}
+	return 0;
+}
+
+static ssize_t
+show_label(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%s\n", input_names[attr->index]);
+}
+
+static ssize_t
+show_in(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	uint16_t val;
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
+
+	val = drv_data->in_val[attr->index];
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t
+show_min(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
+
+	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
+}
+
+static ssize_t
+show_max(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
+
+	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
+}
+
+#define create_voltage_sysfs(idx)			\
+static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,	\
+			show_in, NULL, idx);		\
+static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,	\
+			show_min, NULL, idx);		\
+static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,	\
+			show_max, NULL, idx);		\
+static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,	\
+			show_label, NULL, idx);
+
+create_voltage_sysfs(0);
+create_voltage_sysfs(1);
+create_voltage_sysfs(2);
+create_voltage_sysfs(3);
+create_voltage_sysfs(4);
+
+static struct attribute *menf21bmc_hwmon_attr_volts[] = {
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in0_min.dev_attr.attr,
+	&sensor_dev_attr_in0_max.dev_attr.attr,
+	&sensor_dev_attr_in0_label.dev_attr.attr,
+
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in1_min.dev_attr.attr,
+	&sensor_dev_attr_in1_max.dev_attr.attr,
+	&sensor_dev_attr_in1_label.dev_attr.attr,
+
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in2_min.dev_attr.attr,
+	&sensor_dev_attr_in2_max.dev_attr.attr,
+	&sensor_dev_attr_in2_label.dev_attr.attr,
+
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in3_min.dev_attr.attr,
+	&sensor_dev_attr_in3_max.dev_attr.attr,
+	&sensor_dev_attr_in3_label.dev_attr.attr,
+
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	&sensor_dev_attr_in4_min.dev_attr.attr,
+	&sensor_dev_attr_in4_max.dev_attr.attr,
+	&sensor_dev_attr_in4_label.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group menf21bmc_hwmon_attr_group_volts = {
+	.attrs = menf21bmc_hwmon_attr_volts,
+};
+
+static const struct attribute_group *menf21bmc_hwmon_groups[] = {
+	&menf21bmc_hwmon_attr_group_volts,
+	NULL
+};
+
+static int menf21bmc_hwmon_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct menf21bmc_hwmon *drv_data;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+	struct device *hwmon_dev;
+
+	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
+				GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	drv_data->i2c_client = i2c_client;
+	platform_set_drvdata(pdev, drv_data);
+
+	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to read sensor limits");
+		return ret;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
+							   DEVNAME, drv_data,
+							   menf21bmc_hwmon_groups);
+
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
+
+	return 0;
+}
+
+static struct platform_driver menf21bmc_hwmon = {
+	.probe		= menf21bmc_hwmon_probe,
+	.driver		= {
+		.name		= DEVNAME,
+		.owner		= THIS_MODULE,
+	},
+};
+
+module_platform_driver(menf21bmc_hwmon);
+
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_hwmon");
-- 
2.0.4

Re: [PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Guenter Roeck]

On Wed, Aug 13, 2014 at 10:40:37AM +0200, Andreas Werner wrote:
> Added driver to support the 14F021P00 BMC Hardware Monitoring.
> The BMC is a Board Management Controller including monitoring of the
> board voltages.
> 
> Signed-off-by: Andreas Werner <andreas.werner@men.de>
> ---
>  drivers/hwmon/Kconfig           |   7 ++
>  drivers/hwmon/Makefile          |   1 +
>  drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 246 insertions(+)
>  create mode 100644 drivers/hwmon/menf21bmc_hwmon.c
> 
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 37908ff..437c00f 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -828,6 +828,13 @@ config SENSORS_MCP3021
>  	  This driver can also be built as a module.  If so, the module
>  	  will be called mcp3021.
>  
> +config SENSORS_MENF21BMC_HWMON
> +	tristate "MEN 14F021P00 BMC Hardware Monitoring"
> +	depends on MFD_MENF21BMC && I2C
> +	help
> +	  Say Y here to include support for the MEN 14F021P00 BMC
> +	  hardware monitoring.
> +
>  config SENSORS_ADCXX
>  	tristate "National Semiconductor ADCxxxSxxx"
>  	depends on SPI_MASTER
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 1362382..56ab872 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -114,6 +114,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
>  obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
>  obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
>  obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
> +obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
>  obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
>  obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
>  obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
> diff --git a/drivers/hwmon/menf21bmc_hwmon.c b/drivers/hwmon/menf21bmc_hwmon.c
> new file mode 100644
> index 0000000..ecb0ef1
> --- /dev/null
> +++ b/drivers/hwmon/menf21bmc_hwmon.c
> @@ -0,0 +1,238 @@
> +/*
> + *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
> + *
> + *  This is the core hwmon driver of the MEN 14F021P00 BMC.
> + *  The BMC monitors the board voltages which can be access with this
> + *  driver through sysfs.
> + *
> + *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
> + *
> + *  This program is free software; you can redistribute  it and/or modify it
> + *  under  the terms of  the GNU General  Public License as published by the
> + *  Free Software Foundation;  either version 2 of the  License, or (at your
> + *  option) any later version.

The license statement below states GPL v2, which contradicts the statement here.
Maybe it should just be GPL below ?

> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/jiffies.h>
> +#include <linux/slab.h>
> +#include <linux/i2c.h>
> +
> +#define DEVNAME "menf21bmc_hwmon"
> +
While that makes sense for the driver name, it doesn't really for the hwmon
device. You might want to consider just using "menf21bmc" when you register the
hwmon device.

> +#define BMC_VOLT_COUNT	5
> +#define MENF21BMC_V33	0
> +#define MENF21BMC_V5	1
> +#define MENF21BMC_V12	2
> +#define MENF21BMC_V5_SB	3
> +#define MENF21BMC_VBAT	4
> +
> +#define BMC_CMD_GET_NUM_VOLT 0x8E
> +#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
> +#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
> +#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
> +
> +struct menf21bmc_hwmon {
> +	char valid;
> +	struct i2c_client *i2c_client;
> +	unsigned long last_update;
> +	u16 in_val[BMC_VOLT_COUNT];
> +	u16 in_min[BMC_VOLT_COUNT];
> +	u16 in_max[BMC_VOLT_COUNT];
> +};
> +
> +static const char *const input_names[] = {
> +	[MENF21BMC_V33]		= "MON_3,3V",
> +	[MENF21BMC_V5]		= "MON_5V",
> +	[MENF21BMC_V12]		= "MON_12V",
> +	[MENF21BMC_V5_SB]	= "5V_STANDBY",
> +	[MENF21BMC_VBAT]	= "VBAT"
> +};
> +
> +static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
> +{
> +	int i;
> +	uint16_t val;
> +	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
> +	struct menf21bmc_hwmon *data_ret = drv_data;
> +
> +	if (time_after(jiffies, drv_data->last_update + HZ) || !drv_data->valid) {
> +		for (i = 0; i < BMC_VOLT_COUNT; i++) {
> +			val = i2c_smbus_read_word_data(drv_data->i2c_client,
> +						       IDX_TO_VOLT_INP_CMD(i));
> +			if (val < 0)
> +				goto abort;

I don't really see the point here. You ignore the return value,
yet you abort reading further values. The caller will assume that there was no
error even though the values in in_val were either never initialized or are out
of date.

> +
> +			drv_data->in_val[i] = val;
> +		}
> +		drv_data->last_update = jiffies;
> +		drv_data->valid = 1;
> +	}
> +abort:
> +	return data_ret;

At the same time you do have a separate variable to return.
One of those doesn't make sense.
If the idea was to return an error in data_ret, you would have to assign it
accordingly, and check in the calling code if there was an error or not.

> +}
> +
> +static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
> +{
> +	int i;
> +	uint16_t val;
> +
> +	for (i = 0; i < BMC_VOLT_COUNT; i++) {
> +		val = i2c_smbus_read_word_data(drv_data->i2c_client,
> +					       IDX_TO_VOLT_MIN_CMD(i));
> +		if (val < 0)
> +			return val;
> +
> +		drv_data->in_min[i] = val;
> +
> +		val = i2c_smbus_read_word_data(drv_data->i2c_client,
> +					       IDX_TO_VOLT_MAX_CMD(i));
> +		if (val < 0)
> +			return val;
> +
> +		drv_data->in_max[i] = val;
> +	}
> +	return 0;
> +}
> +
> +static ssize_t
> +show_label(struct device *dev, struct device_attribute *devattr, char *buf)
> +{
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> +
> +	return sprintf(buf, "%s\n", input_names[attr->index]);
> +}
> +
> +static ssize_t
> +show_in(struct device *dev, struct device_attribute *devattr, char *buf)
> +{
> +	uint16_t val;
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> +
> +	val = drv_data->in_val[attr->index];
> +	return sprintf(buf, "%d\n", val);
> +}
> +
> +static ssize_t
> +show_min(struct device *dev, struct device_attribute *devattr, char *buf)
> +{
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> +
> +	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
> +}
> +
> +static ssize_t
> +show_max(struct device *dev, struct device_attribute *devattr, char *buf)
> +{
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> +
> +	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
> +}
> +
You could merge all the above functions into one by using a dual-indexed array
and sensor_device_attribute_2. If you don't, it does not really make sense to
call _hwmon_update to update the input voltages just to display the limits
(which you don't update).

> +#define create_voltage_sysfs(idx)			\
> +static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,	\
> +			show_in, NULL, idx);		\
> +static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,	\
> +			show_min, NULL, idx);		\
> +static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,	\
> +			show_max, NULL, idx);		\
> +static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,	\
> +			show_label, NULL, idx);
> +
> +create_voltage_sysfs(0);
> +create_voltage_sysfs(1);
> +create_voltage_sysfs(2);
> +create_voltage_sysfs(3);
> +create_voltage_sysfs(4);
> +
> +static struct attribute *menf21bmc_hwmon_attr_volts[] = {
> +	&sensor_dev_attr_in0_input.dev_attr.attr,
> +	&sensor_dev_attr_in0_min.dev_attr.attr,
> +	&sensor_dev_attr_in0_max.dev_attr.attr,
> +	&sensor_dev_attr_in0_label.dev_attr.attr,
> +
> +	&sensor_dev_attr_in1_input.dev_attr.attr,
> +	&sensor_dev_attr_in1_min.dev_attr.attr,
> +	&sensor_dev_attr_in1_max.dev_attr.attr,
> +	&sensor_dev_attr_in1_label.dev_attr.attr,
> +
> +	&sensor_dev_attr_in2_input.dev_attr.attr,
> +	&sensor_dev_attr_in2_min.dev_attr.attr,
> +	&sensor_dev_attr_in2_max.dev_attr.attr,
> +	&sensor_dev_attr_in2_label.dev_attr.attr,
> +
> +	&sensor_dev_attr_in3_input.dev_attr.attr,
> +	&sensor_dev_attr_in3_min.dev_attr.attr,
> +	&sensor_dev_attr_in3_max.dev_attr.attr,
> +	&sensor_dev_attr_in3_label.dev_attr.attr,
> +
> +	&sensor_dev_attr_in4_input.dev_attr.attr,
> +	&sensor_dev_attr_in4_min.dev_attr.attr,
> +	&sensor_dev_attr_in4_max.dev_attr.attr,
> +	&sensor_dev_attr_in4_label.dev_attr.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group menf21bmc_hwmon_attr_group_volts = {
> +	.attrs = menf21bmc_hwmon_attr_volts,
> +};
> +
> +static const struct attribute_group *menf21bmc_hwmon_groups[] = {
> +	&menf21bmc_hwmon_attr_group_volts,
> +	NULL
> +};

Please use the ATTRIBUTE_GROUPS() macro.

> +
> +static int menf21bmc_hwmon_probe(struct platform_device *pdev)
> +{
> +	int ret;
> +	struct menf21bmc_hwmon *drv_data;
> +	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
> +	struct device *hwmon_dev;
> +
> +	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
> +				GFP_KERNEL);
> +	if (!drv_data)
> +		return -ENOMEM;
> +
> +	drv_data->i2c_client = i2c_client;
> +	platform_set_drvdata(pdev, drv_data);

What is this used for ?

> +
> +	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to read sensor limits");
> +		return ret;
> +	}
> +
> +	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
> +							   DEVNAME, drv_data,
> +							   menf21bmc_hwmon_groups);
> +
> +	if (IS_ERR(hwmon_dev))
> +		return PTR_ERR(hwmon_dev);
> +
> +	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
> +
> +	return 0;
> +}
> +
> +static struct platform_driver menf21bmc_hwmon = {
> +	.probe		= menf21bmc_hwmon_probe,
> +	.driver		= {
> +		.name		= DEVNAME,
> +		.owner		= THIS_MODULE,
> +	},
> +};
> +
> +module_platform_driver(menf21bmc_hwmon);
> +
> +MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
> +MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:menf21bmc_hwmon");
> -- 
> 2.0.4
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Andreas Werner]

On Thu, Aug 21, 2014 at 11:37:52AM -0700, Guenter Roeck wrote:
> On Wed, Aug 13, 2014 at 10:40:37AM +0200, Andreas Werner wrote:
> > Added driver to support the 14F021P00 BMC Hardware Monitoring.
> > The BMC is a Board Management Controller including monitoring of the
> > board voltages.
> > 
> > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > ---
> >  drivers/hwmon/Kconfig           |   7 ++
> >  drivers/hwmon/Makefile          |   1 +
> >  drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 246 insertions(+)
> >  create mode 100644 drivers/hwmon/menf21bmc_hwmon.c
> > 
> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > index 37908ff..437c00f 100644
> > --- a/drivers/hwmon/Kconfig
> > +++ b/drivers/hwmon/Kconfig
> > @@ -828,6 +828,13 @@ config SENSORS_MCP3021
> >  	  This driver can also be built as a module.  If so, the module
> >  	  will be called mcp3021.
> >  
> > +config SENSORS_MENF21BMC_HWMON
> > +	tristate "MEN 14F021P00 BMC Hardware Monitoring"
> > +	depends on MFD_MENF21BMC && I2C
> > +	help
> > +	  Say Y here to include support for the MEN 14F021P00 BMC
> > +	  hardware monitoring.
> > +
> >  config SENSORS_ADCXX
> >  	tristate "National Semiconductor ADCxxxSxxx"
> >  	depends on SPI_MASTER
> > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> > index 1362382..56ab872 100644
> > --- a/drivers/hwmon/Makefile
> > +++ b/drivers/hwmon/Makefile
> > @@ -114,6 +114,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
> >  obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
> >  obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> >  obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
> > +obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
> >  obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
> >  obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
> >  obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
> > diff --git a/drivers/hwmon/menf21bmc_hwmon.c b/drivers/hwmon/menf21bmc_hwmon.c
> > new file mode 100644
> > index 0000000..ecb0ef1
> > --- /dev/null
> > +++ b/drivers/hwmon/menf21bmc_hwmon.c
> > @@ -0,0 +1,238 @@
> > +/*
> > + *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
> > + *
> > + *  This is the core hwmon driver of the MEN 14F021P00 BMC.
> > + *  The BMC monitors the board voltages which can be access with this
> > + *  driver through sysfs.
> > + *
> > + *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
> > + *
> > + *  This program is free software; you can redistribute  it and/or modify it
> > + *  under  the terms of  the GNU General  Public License as published by the
> > + *  Free Software Foundation;  either version 2 of the  License, or (at your
> > + *  option) any later version.
> 
> The license statement below states GPL v2, which contradicts the statement here.
> Maybe it should just be GPL below ?

Why dos it contradict? This is both GPLv2, in the header and in the MODULE_LICENSE
like i have changed it in the other slave devices and the mfd.

> 
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/hwmon.h>
> > +#include <linux/hwmon-sysfs.h>
> > +#include <linux/jiffies.h>
> > +#include <linux/slab.h>
> > +#include <linux/i2c.h>
> > +
> > +#define DEVNAME "menf21bmc_hwmon"
> > +
> While that makes sense for the driver name, it doesn't really for the hwmon
> device. You might want to consider just using "menf21bmc" when you register the
> hwmon device.
>

menf21bmc is the name of the MFD driver. This name is to distinguish each of
the slaves. For that the name represent that this device is a slave of "menf21bmc"
and a "hwmon" of its own.
 
> > +#define BMC_VOLT_COUNT	5
> > +#define MENF21BMC_V33	0
> > +#define MENF21BMC_V5	1
> > +#define MENF21BMC_V12	2
> > +#define MENF21BMC_V5_SB	3
> > +#define MENF21BMC_VBAT	4
> > +
> > +#define BMC_CMD_GET_NUM_VOLT 0x8E
> > +#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
> > +#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
> > +#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
> > +
> > +struct menf21bmc_hwmon {
> > +	char valid;
> > +	struct i2c_client *i2c_client;
> > +	unsigned long last_update;
> > +	u16 in_val[BMC_VOLT_COUNT];
> > +	u16 in_min[BMC_VOLT_COUNT];
> > +	u16 in_max[BMC_VOLT_COUNT];
> > +};
> > +
> > +static const char *const input_names[] = {
> > +	[MENF21BMC_V33]		= "MON_3,3V",
> > +	[MENF21BMC_V5]		= "MON_5V",
> > +	[MENF21BMC_V12]		= "MON_12V",
> > +	[MENF21BMC_V5_SB]	= "5V_STANDBY",
> > +	[MENF21BMC_VBAT]	= "VBAT"
> > +};
> > +
> > +static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
> > +{
> > +	int i;
> > +	uint16_t val;
> > +	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
> > +	struct menf21bmc_hwmon *data_ret = drv_data;
> > +
> > +	if (time_after(jiffies, drv_data->last_update + HZ) || !drv_data->valid) {
> > +		for (i = 0; i < BMC_VOLT_COUNT; i++) {
> > +			val = i2c_smbus_read_word_data(drv_data->i2c_client,
> > +						       IDX_TO_VOLT_INP_CMD(i));
> > +			if (val < 0)
> > +				goto abort;
> 
> I don't really see the point here. You ignore the return value,
> yet you abort reading further values. The caller will assume that there was no
> error even though the values in in_val were either never initialized or are out
> of date.
> 

Argh thats true.
I have checked out some other drivers and they just read the value from the 
i2c bus and save the value into the struct without error checking.
Is that the normal way?
If yes then the caller hast to check if the value is a correct voltage value.

The other way what i see is to read the value, check if there is no error and then
save the new value to the struct. If there is an error during read then we just
do not update the value and let it as it is.
If I go this way then i do not need the second struct as the return value.

> > +
> > +			drv_data->in_val[i] = val;
> > +		}
> > +		drv_data->last_update = jiffies;
> > +		drv_data->valid = 1;
> > +	}
> > +abort:
> > +	return data_ret;
> 
> At the same time you do have a separate variable to return.
> One of those doesn't make sense.
> If the idea was to return an error in data_ret, you would have to assign it
> accordingly, and check in the calling code if there was an error or not.

Will be changed, see above.

> 
> > +}
> > +
> > +static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
> > +{
> > +	int i;
> > +	uint16_t val;
> > +
> > +	for (i = 0; i < BMC_VOLT_COUNT; i++) {
> > +		val = i2c_smbus_read_word_data(drv_data->i2c_client,
> > +					       IDX_TO_VOLT_MIN_CMD(i));
> > +		if (val < 0)
> > +			return val;
> > +
> > +		drv_data->in_min[i] = val;
> > +
> > +		val = i2c_smbus_read_word_data(drv_data->i2c_client,
> > +					       IDX_TO_VOLT_MAX_CMD(i));
> > +		if (val < 0)
> > +			return val;
> > +
> > +		drv_data->in_max[i] = val;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static ssize_t
> > +show_label(struct device *dev, struct device_attribute *devattr, char *buf)
> > +{
> > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > +
> > +	return sprintf(buf, "%s\n", input_names[attr->index]);
> > +}
> > +
> > +static ssize_t
> > +show_in(struct device *dev, struct device_attribute *devattr, char *buf)
> > +{
> > +	uint16_t val;
> > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> > +
> > +	val = drv_data->in_val[attr->index];
> > +	return sprintf(buf, "%d\n", val);
> > +}
> > +
> > +static ssize_t
> > +show_min(struct device *dev, struct device_attribute *devattr, char *buf)
> > +{
> > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> > +
> > +	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
> > +}
> > +
> > +static ssize_t
> > +show_max(struct device *dev, struct device_attribute *devattr, char *buf)
> > +{
> > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> > +
> > +	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
> > +}
> > +
> You could merge all the above functions into one by using a dual-indexed array
> and sensor_device_attribute_2. If you don't, it does not really make sense to
> call _hwmon_update to update the input voltages just to display the limits
> (which you don't update).
> 

I do not want to merge it to one function. I will delete the upate call
for min and max values.

> > +#define create_voltage_sysfs(idx)			\
> > +static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,	\
> > +			show_in, NULL, idx);		\
> > +static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,	\
> > +			show_min, NULL, idx);		\
> > +static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,	\
> > +			show_max, NULL, idx);		\
> > +static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,	\
> > +			show_label, NULL, idx);
> > +
> > +create_voltage_sysfs(0);
> > +create_voltage_sysfs(1);
> > +create_voltage_sysfs(2);
> > +create_voltage_sysfs(3);
> > +create_voltage_sysfs(4);
> > +
> > +static struct attribute *menf21bmc_hwmon_attr_volts[] = {
> > +	&sensor_dev_attr_in0_input.dev_attr.attr,
> > +	&sensor_dev_attr_in0_min.dev_attr.attr,
> > +	&sensor_dev_attr_in0_max.dev_attr.attr,
> > +	&sensor_dev_attr_in0_label.dev_attr.attr,
> > +
> > +	&sensor_dev_attr_in1_input.dev_attr.attr,
> > +	&sensor_dev_attr_in1_min.dev_attr.attr,
> > +	&sensor_dev_attr_in1_max.dev_attr.attr,
> > +	&sensor_dev_attr_in1_label.dev_attr.attr,
> > +
> > +	&sensor_dev_attr_in2_input.dev_attr.attr,
> > +	&sensor_dev_attr_in2_min.dev_attr.attr,
> > +	&sensor_dev_attr_in2_max.dev_attr.attr,
> > +	&sensor_dev_attr_in2_label.dev_attr.attr,
> > +
> > +	&sensor_dev_attr_in3_input.dev_attr.attr,
> > +	&sensor_dev_attr_in3_min.dev_attr.attr,
> > +	&sensor_dev_attr_in3_max.dev_attr.attr,
> > +	&sensor_dev_attr_in3_label.dev_attr.attr,
> > +
> > +	&sensor_dev_attr_in4_input.dev_attr.attr,
> > +	&sensor_dev_attr_in4_min.dev_attr.attr,
> > +	&sensor_dev_attr_in4_max.dev_attr.attr,
> > +	&sensor_dev_attr_in4_label.dev_attr.attr,
> > +	NULL
> > +};
> > +
> > +static const struct attribute_group menf21bmc_hwmon_attr_group_volts = {
> > +	.attrs = menf21bmc_hwmon_attr_volts,
> > +};
> > +
> > +static const struct attribute_group *menf21bmc_hwmon_groups[] = {
> > +	&menf21bmc_hwmon_attr_group_volts,
> > +	NULL
> > +};
> 
> Please use the ATTRIBUTE_GROUPS() macro.

Ok i will use the macro.

> 
> > +
> > +static int menf21bmc_hwmon_probe(struct platform_device *pdev)
> > +{
> > +	int ret;
> > +	struct menf21bmc_hwmon *drv_data;
> > +	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
> > +	struct device *hwmon_dev;
> > +
> > +	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
> > +				GFP_KERNEL);
> > +	if (!drv_data)
> > +		return -ENOMEM;
> > +
> > +	drv_data->i2c_client = i2c_client;
> > +	platform_set_drvdata(pdev, drv_data);
> 
> What is this used for ?

For the update function. I need to access the drv_data there.
May this could change, depends on the changes of the update function.
> 
> > +
> > +	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "failed to read sensor limits");
> > +		return ret;
> > +	}
> > +
> > +	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
> > +							   DEVNAME, drv_data,
> > +							   menf21bmc_hwmon_groups);
> > +
> > +	if (IS_ERR(hwmon_dev))
> > +		return PTR_ERR(hwmon_dev);
> > +
> > +	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
> > +
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver menf21bmc_hwmon = {
> > +	.probe		= menf21bmc_hwmon_probe,
> > +	.driver		= {
> > +		.name		= DEVNAME,
> > +		.owner		= THIS_MODULE,
> > +	},
> > +};
> > +
> > +module_platform_driver(menf21bmc_hwmon);
> > +
> > +MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
> > +MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
> > +MODULE_LICENSE("GPL v2");
> > +MODULE_ALIAS("platform:menf21bmc_hwmon");
> > -- 
> > 2.0.4
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 

Re: [PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Guenter Roeck]

On Fri, Aug 22, 2014 at 10:38:11AM +0200, Andreas Werner wrote:
> On Thu, Aug 21, 2014 at 11:37:52AM -0700, Guenter Roeck wrote:
> > On Wed, Aug 13, 2014 at 10:40:37AM +0200, Andreas Werner wrote:
> > > Added driver to support the 14F021P00 BMC Hardware Monitoring.
> > > The BMC is a Board Management Controller including monitoring of the
> > > board voltages.
> > > 
> > > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > > ---
> > >  drivers/hwmon/Kconfig           |   7 ++
> > >  drivers/hwmon/Makefile          |   1 +
> > >  drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 246 insertions(+)
> > >  create mode 100644 drivers/hwmon/menf21bmc_hwmon.c
> > > 
> > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > > index 37908ff..437c00f 100644
> > > --- a/drivers/hwmon/Kconfig
> > > +++ b/drivers/hwmon/Kconfig
> > > @@ -828,6 +828,13 @@ config SENSORS_MCP3021
> > >  	  This driver can also be built as a module.  If so, the module
> > >  	  will be called mcp3021.
> > >  
> > > +config SENSORS_MENF21BMC_HWMON
> > > +	tristate "MEN 14F021P00 BMC Hardware Monitoring"
> > > +	depends on MFD_MENF21BMC && I2C
> > > +	help
> > > +	  Say Y here to include support for the MEN 14F021P00 BMC
> > > +	  hardware monitoring.
> > > +
> > >  config SENSORS_ADCXX
> > >  	tristate "National Semiconductor ADCxxxSxxx"
> > >  	depends on SPI_MASTER
> > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> > > index 1362382..56ab872 100644
> > > --- a/drivers/hwmon/Makefile
> > > +++ b/drivers/hwmon/Makefile
> > > @@ -114,6 +114,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
> > >  obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
> > >  obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> > >  obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
> > > +obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
> > >  obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
> > >  obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
> > >  obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
> > > diff --git a/drivers/hwmon/menf21bmc_hwmon.c b/drivers/hwmon/menf21bmc_hwmon.c
> > > new file mode 100644
> > > index 0000000..ecb0ef1
> > > --- /dev/null
> > > +++ b/drivers/hwmon/menf21bmc_hwmon.c
> > > @@ -0,0 +1,238 @@
> > > +/*
> > > + *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
> > > + *
> > > + *  This is the core hwmon driver of the MEN 14F021P00 BMC.
> > > + *  The BMC monitors the board voltages which can be access with this
> > > + *  driver through sysfs.
> > > + *
> > > + *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
> > > + *
> > > + *  This program is free software; you can redistribute  it and/or modify it
> > > + *  under  the terms of  the GNU General  Public License as published by the
> > > + *  Free Software Foundation;  either version 2 of the  License, or (at your
> > > + *  option) any later version.
> > 
> > The license statement below states GPL v2, which contradicts the statement here.
> > Maybe it should just be GPL below ?
> 
> Why dos it contradict? This is both GPLv2, in the header and in the MODULE_LICENSE
> like i have changed it in the other slave devices and the mfd.
> 
Ok, your call.

> > 
> > > + */
> > > +
> > > +#include <linux/module.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/hwmon.h>
> > > +#include <linux/hwmon-sysfs.h>
> > > +#include <linux/jiffies.h>
> > > +#include <linux/slab.h>
> > > +#include <linux/i2c.h>
> > > +
> > > +#define DEVNAME "menf21bmc_hwmon"
> > > +
> > While that makes sense for the driver name, it doesn't really for the hwmon
> > device. You might want to consider just using "menf21bmc" when you register the
> > hwmon device.
> >
> 
> menf21bmc is the name of the MFD driver. This name is to distinguish each of
> the slaves. For that the name represent that this device is a slave of "menf21bmc"
> and a "hwmon" of its own.
>  
Yes, but that doesn' mean that the name registered with the hwmon subsystem has
to have "hwmon" in it; this is independent of the driver name. That is still
redundant. Anyway, your driver, your call.

> > > +#define BMC_VOLT_COUNT	5
> > > +#define MENF21BMC_V33	0
> > > +#define MENF21BMC_V5	1
> > > +#define MENF21BMC_V12	2
> > > +#define MENF21BMC_V5_SB	3
> > > +#define MENF21BMC_VBAT	4
> > > +
> > > +#define BMC_CMD_GET_NUM_VOLT 0x8E
> > > +#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
> > > +#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
> > > +#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
> > > +
> > > +struct menf21bmc_hwmon {
> > > +	char valid;
> > > +	struct i2c_client *i2c_client;
> > > +	unsigned long last_update;
> > > +	u16 in_val[BMC_VOLT_COUNT];
> > > +	u16 in_min[BMC_VOLT_COUNT];
> > > +	u16 in_max[BMC_VOLT_COUNT];
> > > +};
> > > +
> > > +static const char *const input_names[] = {
> > > +	[MENF21BMC_V33]		= "MON_3,3V",
> > > +	[MENF21BMC_V5]		= "MON_5V",
> > > +	[MENF21BMC_V12]		= "MON_12V",
> > > +	[MENF21BMC_V5_SB]	= "5V_STANDBY",
> > > +	[MENF21BMC_VBAT]	= "VBAT"
> > > +};
> > > +
> > > +static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
> > > +{
> > > +	int i;
> > > +	uint16_t val;
> > > +	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
> > > +	struct menf21bmc_hwmon *data_ret = drv_data;
> > > +
> > > +	if (time_after(jiffies, drv_data->last_update + HZ) || !drv_data->valid) {
> > > +		for (i = 0; i < BMC_VOLT_COUNT; i++) {
> > > +			val = i2c_smbus_read_word_data(drv_data->i2c_client,
> > > +						       IDX_TO_VOLT_INP_CMD(i));
> > > +			if (val < 0)
> > > +				goto abort;
> > 
> > I don't really see the point here. You ignore the return value,
> > yet you abort reading further values. The caller will assume that there was no
> > error even though the values in in_val were either never initialized or are out
> > of date.
> > 
> 
> Argh thats true.
> I have checked out some other drivers and they just read the value from the 
> i2c bus and save the value into the struct without error checking.
> Is that the normal way?
> If yes then the caller hast to check if the value is a correct voltage value.

You have a number of options: Ignore the error, but consistently. Not a good
idea, not done by recent drivers, but if you think your chip never reports an
error fine with me. Abort if an error occurs, and return the error code from the
function. Store the error in the data, and check the data for error in the
calling code.

My personal preference would be to return an error code from the function (with
PTR_ERR) and check it in the calling code (with ERR_PTR), but it is really your
call.

> 
> The other way what i see is to read the value, check if there is no error and then
> save the new value to the struct. If there is an error during read then we just
> do not update the value and let it as it is.

This is akin to ignoring errors. Again, I don't think this would be a good idea,
but it is your call to make.

> If I go this way then i do not need the second struct as the return value.
> 
> > > +
> > > +			drv_data->in_val[i] = val;
> > > +		}
> > > +		drv_data->last_update = jiffies;
> > > +		drv_data->valid = 1;
> > > +	}
> > > +abort:
> > > +	return data_ret;
> > 
> > At the same time you do have a separate variable to return.
> > One of those doesn't make sense.
> > If the idea was to return an error in data_ret, you would have to assign it
> > accordingly, and check in the calling code if there was an error or not.
> 
> Will be changed, see above.
> 
> > 
> > > +}
> > > +
> > > +static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
> > > +{
> > > +	int i;
> > > +	uint16_t val;
> > > +
> > > +	for (i = 0; i < BMC_VOLT_COUNT; i++) {
> > > +		val = i2c_smbus_read_word_data(drv_data->i2c_client,
> > > +					       IDX_TO_VOLT_MIN_CMD(i));
> > > +		if (val < 0)
> > > +			return val;
> > > +
> > > +		drv_data->in_min[i] = val;
> > > +
> > > +		val = i2c_smbus_read_word_data(drv_data->i2c_client,
> > > +					       IDX_TO_VOLT_MAX_CMD(i));
> > > +		if (val < 0)
> > > +			return val;
> > > +
> > > +		drv_data->in_max[i] = val;
> > > +	}
> > > +	return 0;
> > > +}
> > > +
> > > +static ssize_t
> > > +show_label(struct device *dev, struct device_attribute *devattr, char *buf)
> > > +{
> > > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > > +
> > > +	return sprintf(buf, "%s\n", input_names[attr->index]);
> > > +}
> > > +
> > > +static ssize_t
> > > +show_in(struct device *dev, struct device_attribute *devattr, char *buf)
> > > +{
> > > +	uint16_t val;
> > > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > > +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> > > +
> > > +	val = drv_data->in_val[attr->index];
> > > +	return sprintf(buf, "%d\n", val);
> > > +}
> > > +
> > > +static ssize_t
> > > +show_min(struct device *dev, struct device_attribute *devattr, char *buf)
> > > +{
> > > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > > +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> > > +
> > > +	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
> > > +}
> > > +
> > > +static ssize_t
> > > +show_max(struct device *dev, struct device_attribute *devattr, char *buf)
> > > +{
> > > +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> > > +	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
> > > +
> > > +	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
> > > +}
> > > +
> > You could merge all the above functions into one by using a dual-indexed array
> > and sensor_device_attribute_2. If you don't, it does not really make sense to
> > call _hwmon_update to update the input voltages just to display the limits
> > (which you don't update).
> > 
> 
> I do not want to merge it to one function. I will delete the upate call
> for min and max values.
> 
> > > +#define create_voltage_sysfs(idx)			\
> > > +static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,	\
> > > +			show_in, NULL, idx);		\
> > > +static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,	\
> > > +			show_min, NULL, idx);		\
> > > +static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,	\
> > > +			show_max, NULL, idx);		\
> > > +static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,	\
> > > +			show_label, NULL, idx);
> > > +
> > > +create_voltage_sysfs(0);
> > > +create_voltage_sysfs(1);
> > > +create_voltage_sysfs(2);
> > > +create_voltage_sysfs(3);
> > > +create_voltage_sysfs(4);
> > > +
> > > +static struct attribute *menf21bmc_hwmon_attr_volts[] = {
> > > +	&sensor_dev_attr_in0_input.dev_attr.attr,
> > > +	&sensor_dev_attr_in0_min.dev_attr.attr,
> > > +	&sensor_dev_attr_in0_max.dev_attr.attr,
> > > +	&sensor_dev_attr_in0_label.dev_attr.attr,
> > > +
> > > +	&sensor_dev_attr_in1_input.dev_attr.attr,
> > > +	&sensor_dev_attr_in1_min.dev_attr.attr,
> > > +	&sensor_dev_attr_in1_max.dev_attr.attr,
> > > +	&sensor_dev_attr_in1_label.dev_attr.attr,
> > > +
> > > +	&sensor_dev_attr_in2_input.dev_attr.attr,
> > > +	&sensor_dev_attr_in2_min.dev_attr.attr,
> > > +	&sensor_dev_attr_in2_max.dev_attr.attr,
> > > +	&sensor_dev_attr_in2_label.dev_attr.attr,
> > > +
> > > +	&sensor_dev_attr_in3_input.dev_attr.attr,
> > > +	&sensor_dev_attr_in3_min.dev_attr.attr,
> > > +	&sensor_dev_attr_in3_max.dev_attr.attr,
> > > +	&sensor_dev_attr_in3_label.dev_attr.attr,
> > > +
> > > +	&sensor_dev_attr_in4_input.dev_attr.attr,
> > > +	&sensor_dev_attr_in4_min.dev_attr.attr,
> > > +	&sensor_dev_attr_in4_max.dev_attr.attr,
> > > +	&sensor_dev_attr_in4_label.dev_attr.attr,
> > > +	NULL
> > > +};
> > > +
> > > +static const struct attribute_group menf21bmc_hwmon_attr_group_volts = {
> > > +	.attrs = menf21bmc_hwmon_attr_volts,
> > > +};
> > > +
> > > +static const struct attribute_group *menf21bmc_hwmon_groups[] = {
> > > +	&menf21bmc_hwmon_attr_group_volts,
> > > +	NULL
> > > +};
> > 
> > Please use the ATTRIBUTE_GROUPS() macro.
> 
> Ok i will use the macro.
> 
> > 
> > > +
> > > +static int menf21bmc_hwmon_probe(struct platform_device *pdev)
> > > +{
> > > +	int ret;
> > > +	struct menf21bmc_hwmon *drv_data;
> > > +	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
> > > +	struct device *hwmon_dev;
> > > +
> > > +	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
> > > +				GFP_KERNEL);
> > > +	if (!drv_data)
> > > +		return -ENOMEM;
> > > +
> > > +	drv_data->i2c_client = i2c_client;
> > > +	platform_set_drvdata(pdev, drv_data);
> > 
> > What is this used for ?
> 
> For the update function. I need to access the drv_data there.
> May this could change, depends on the changes of the update function.

drv_data is passed to the registration function below, which attaches it to the
hwmon device. dev_get_drvdata gets it from the hwmon device, not from the
platform device. I don't see any code which reads drv_data from the platform
device. You might need it if the driver had a remove function, but that is not
the case.

Guenter

> > 
> > > +
> > > +	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
> > > +	if (ret) {
> > > +		dev_err(&pdev->dev, "failed to read sensor limits");
> > > +		return ret;
> > > +	}
> > > +
> > > +	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
> > > +							   DEVNAME, drv_data,
> > > +							   menf21bmc_hwmon_groups);
> > > +
> > > +	if (IS_ERR(hwmon_dev))
> > > +		return PTR_ERR(hwmon_dev);
> > > +
> > > +	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static struct platform_driver menf21bmc_hwmon = {
> > > +	.probe		= menf21bmc_hwmon_probe,
> > > +	.driver		= {
> > > +		.name		= DEVNAME,
> > > +		.owner		= THIS_MODULE,
> > > +	},
> > > +};
> > > +
> > > +module_platform_driver(menf21bmc_hwmon);
> > > +
> > > +MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
> > > +MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
> > > +MODULE_LICENSE("GPL v2");
> > > +MODULE_ALIAS("platform:menf21bmc_hwmon");
> > > -- 
> > > 2.0.4
> > > 
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > 
> 

Re: [PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Guenter Roeck]

On Wed, Aug 13, 2014 at 10:40:37AM +0200, Andreas Werner wrote:
> Added driver to support the 14F021P00 BMC Hardware Monitoring.
> The BMC is a Board Management Controller including monitoring of the
> board voltages.
> 
> Signed-off-by: Andreas Werner <andreas.werner@men.de>
> ---
>  drivers/hwmon/Kconfig           |   7 ++
>  drivers/hwmon/Makefile          |   1 +
>  drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++

Forgot: Please also provide Documentation/hwmon/menf21bmc.

Thanks,
Guenter

Re: [PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Andreas Werner]

On Thu, Aug 21, 2014 at 11:45:01AM -0700, Guenter Roeck wrote:
> On Wed, Aug 13, 2014 at 10:40:37AM +0200, Andreas Werner wrote:
> > Added driver to support the 14F021P00 BMC Hardware Monitoring.
> > The BMC is a Board Management Controller including monitoring of the
> > board voltages.
> > 
> > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > ---
> >  drivers/hwmon/Kconfig           |   7 ++
> >  drivers/hwmon/Makefile          |   1 +
> >  drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++
> 
> Forgot: Please also provide Documentation/hwmon/menf21bmc.
> 

Did not know that i have to do it.
But you are right it is good to have one.

> Thanks,
> Guenter

Re: [PATCH v4 4/4] drivers/hwmon/menf21bmc_hwmon: introduce MEN14F021P00 BMC HWMON driver

[Guenter Roeck]

On Fri, Aug 22, 2014 at 10:39:31AM +0200, Andreas Werner wrote:
> On Thu, Aug 21, 2014 at 11:45:01AM -0700, Guenter Roeck wrote:
> > On Wed, Aug 13, 2014 at 10:40:37AM +0200, Andreas Werner wrote:
> > > Added driver to support the 14F021P00 BMC Hardware Monitoring.
> > > The BMC is a Board Management Controller including monitoring of the
> > > board voltages.
> > > 
> > > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > > ---
> > >  drivers/hwmon/Kconfig           |   7 ++
> > >  drivers/hwmon/Makefile          |   1 +
> > >  drivers/hwmon/menf21bmc_hwmon.c | 238 ++++++++++++++++++++++++++++++++++++++++
> > 
> > Forgot: Please also provide Documentation/hwmon/menf21bmc.
> > 
> 
> Did not know that i have to do it.
> But you are right it is good to have one.
> 
Documentation/hwmon/submitting-patches is quite useful.

Thanks,
Guenter