[patch v6 0/1] Introduce smlxreg LED driver

[patch v6 0/1] Introduce smlxreg LED driver

[Vadim Pasternak]

This patch introduces LED driver, based on regmap interface.
This patch depends on:
include/linux/platform_data/mlxreg.h?h=next-20180209 from
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/
because it includes include/linux/platform_data/mlxreg.h from this patch.

Vadim Pasternak (1):
  leds: add driver for support Mellanox regmap LEDs for BMC and x86
    platform

 MAINTAINERS                |   1 +
 drivers/leds/Kconfig       |  10 ++
 drivers/leds/Makefile      |   1 +
 drivers/leds/leds-mlxreg.c | 311 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 323 insertions(+)
 create mode 100644 drivers/leds/leds-mlxreg.c

-- 
2.1.4

[patch v6 1/1] leds: add driver for support Mellanox regmap LEDs for BMC and x86 platform

[Vadim Pasternak]

Driver obtains LED devices according to system configuration and creates
devices in form: "devicename:color:function", like
The full path is to be:
/sys/class/leds/mlxreg\:status\:amber/brightness
After timer trigger activation:
echo timer > /sys/class/leds/mlxreg\:status\:amber/trigger
Attributes for LED blinking will appaer in sysfs infrastructure:
/sys/class/leds/mlxreg\:status\:amber/delay_off
/sys/class/leds/mlxreg\:status\:amber/delay_on

LED setting is controlled through the on-board programmable devices,
which exports its register map. This device could be attached to any
bus type, for which register mapping is supported.

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
v5->v6
 Changes added by Vadim:
  - Change year to 2018 in Copyright;
  - Change structure mlxreg_core_led_platform_data name to common name
    mlxreg_core_platform_data, as it has been pushed to
    git://git.infradead.org/linux-platform-drivers-x86.git to branch,
    commit 1f976f6978bf6156ce822eb279ac86c519b10329 (1f976f6), file
    include/linux/platform_data/mlxreg.h
  - Add orange color, as alternative to red (some systems use orange,
    instead of red);
  - Drop mlxreg_led_dt_match, since the driver is to be activated by another
    common Mellanox platform driver, mlx-platform or mlx-platform-of;
v4->v5
 Comments pointed out by Jacek:
 - Make consistent naming in mlxreg_led_brightness_set,
   mlxreg_led_brightness_get, mlxreg_led_config;
 - Remove unnecessary data assignment in mlxreg_led_config;
 Changes added by Vadim:
 - Add internal structure mlxreg_led_data to leds-mlxreg.c;
v3->v4
 Comments pointed out by Jacek:
 - add led in declaration mlxreg_led_store_hw and mlxreg_led_get_hw;
 - rearrange local variables names in mlxreg_led_config;
 Comments pointed out by Pavel:
 - replace _HALF/_FULL with BLINK_3HZ/BLINK_6HZ;
 - in mlxreg_led_get_hw just return after access error;
 - explicit check for green led is not added, since control device can be
   programmed for blue LED and this case it reuses masks of green LED.
v2->v3:
 Comments pointed out by Jacek:
 - fix order in includes;
 - add declaration pdata in mlxreg_led_store_hw and mlxreg_led_get_hw;
 - add declaration of led_data in mlxreg_led_config;
 - use LED_ON in assignment instead of 1;
 - fix mutex call in mlxreg_led_remove;
v1->v2:
 Comments pointed out by Jacek:
 - remove macros MLXREG_MAP and MLXREG_CDEV;
 - brightness_set_blocking insteaf of brightness_set, this fix allows
   removing of context validation and workqueue and also three fields from
   struct mlxreg_core_led_data in mlxreg.h;
 - remove MLXREG_LED_NAME;
 - extend Kconfig description;
 Changes added by Vadim:
 - remove unnecessary includes after dropping workqueue;
---
 MAINTAINERS                |   1 +
 drivers/leds/Kconfig       |  10 ++
 drivers/leds/Makefile      |   1 +
 drivers/leds/leds-mlxreg.c | 311 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 323 insertions(+)
 create mode 100644 drivers/leds/leds-mlxreg.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 95c3fa1..96625b2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8916,6 +8916,7 @@ M:	Vadim Pasternak <vadimp@mellanox.com>
 L:	linux-leds@vger.kernel.org
 S:	Supported
 F:	drivers/leds/leds-mlxcpld.c
+F:	drivers/leds/leds-mlxreg.c
 F:	Documentation/leds/leds-mlxcpld.txt
 
 MELLANOX PLATFORM DRIVER
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 3e763d2..c98abe1 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -694,6 +694,16 @@ config LEDS_MLXCPLD
 	  This option enabled support for the LEDs on the Mellanox
 	  boards. Say Y to enabled these.
 
+config LEDS_MLXREG
+	tristate "LED support for the Mellanox switches management control"
+	depends on LEDS_CLASS
+	help
+	  This option enabled support for the LEDs on the Mellanox Ethernet and
+	  InfiniBand switches. The driver can be activated from the device tree
+	  or by the direct platform device add call. Say Y to enabled these. To
+	  compile this driver as a module, choose 'M' here: the module will be
+	  called leds-mlxreg.
+
 config LEDS_USER
 	tristate "Userspace LED support"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 987884a..91eca81 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-is31fl319x.o
 obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
 obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o
 obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o
+obj-$(CONFIG_LEDS_MLXREG)		+= leds-mlxreg.o
 obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
 obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
 obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
new file mode 100644
index 0000000..4dd2bd8
--- /dev/null
+++ b/drivers/leds/leds-mlxreg.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_data/mlxreg.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* Codes for LEDs. */
+#define MLXREG_LED_OFFSET_BLINK_3HZ	0x01 /* Offset from solid: 3Hz blink */
+#define MLXREG_LED_OFFSET_BLINK_6HZ	0x02 /* Offset from solid: 6Hz blink */
+#define MLXREG_LED_IS_OFF		0x00 /* Off */
+#define MLXREG_LED_RED_SOLID		0x05 /* Solid red */
+#define MLXREG_LED_GREEN_SOLID		0x0D /* Solid green */
+#define MLXREG_LED_AMBER_SOLID		0x09 /* Solid amber */
+#define MLXREG_LED_BLINK_3HZ		167 /* ~167 msec off/on - HW support */
+#define MLXREG_LED_BLINK_6HZ		83 /* ~83 msec off/on - HW support */
+
+/**
+ * struct mlxreg_led_data - led control data:
+ *
+ * @data: led configuration data;
+ * @led_classdev: led class data;
+ * @base_color: base led color (other colors have constant offset from base);
+ * @led_data: led data;
+ * @data_parent: pointer to private device control data of parent;
+ */
+struct mlxreg_led_data {
+	struct mlxreg_core_data *data;
+	struct led_classdev led_cdev;
+	u8 base_color;
+	void *data_parent;
+	char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
+};
+
+#define cdev_to_priv(c) container_of(c, struct mlxreg_led_data, led_cdev)
+
+/**
+ * struct mlxreg_led_priv_data - platform private data:
+ *
+ * @pdev: platform device;
+ * @pdata: platform data;
+ * @access_lock: mutex for attribute IO access;
+ */
+struct mlxreg_led_priv_data {
+	struct platform_device *pdev;
+	struct mlxreg_core_platform_data *pdata;
+	struct mutex access_lock; /* protect IO operations */
+};
+
+static int
+mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset)
+{
+	struct mlxreg_led_priv_data *priv = led_data->data_parent;
+	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
+	struct mlxreg_core_data *data = led_data->data;
+	u32 regval;
+	u32 nib;
+	int ret;
+
+	/*
+	 * Each LED is controlled through low or high nibble of the relevant
+	 * register byte. Register offset is specified by off parameter.
+	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
+	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
+	 * green.
+	 * Parameter mask specifies which nibble is used for specific LED: mask
+	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
+	 * higher nibble (bits from 4 to 7).
+	 */
+	mutex_lock(&priv->access_lock);
+
+	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
+	if (ret)
+		goto access_error;
+
+	nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
+	      rol32(vset, data->bit + 4);
+	regval = (regval & data->mask) | nib;
+
+	ret = regmap_write(led_pdata->regmap, data->reg, regval);
+
+access_error:
+	mutex_unlock(&priv->access_lock);
+
+	return ret;
+}
+
+static enum led_brightness
+mlxreg_led_get_hw(struct mlxreg_led_data *led_data)
+{
+	struct mlxreg_led_priv_data *priv = led_data->data_parent;
+	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
+	struct mlxreg_core_data *data = led_data->data;
+	u32 regval;
+	int ret;
+
+	/*
+	 * Each LED is controlled through low or high nibble of the relevant
+	 * register byte. Register offset is specified by off parameter.
+	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
+	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
+	 * green.
+	 * Parameter mask specifies which nibble is used for specific LED: mask
+	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
+	 * higher nibble (bits from 4 to 7).
+	 */
+	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
+	if (ret < 0) {
+		dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
+			 ret);
+		/* Assume the LED is OFF */
+		return LED_OFF;
+	}
+
+	regval = regval & ~data->mask;
+	regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
+		 data->bit) : ror32(regval, data->bit + 4);
+	if (regval >= led_data->base_color &&
+	    regval <= (led_data->base_color + MLXREG_LED_OFFSET_BLINK_6HZ))
+		ret = LED_FULL;
+	else
+		ret = LED_OFF;
+
+	return ret;
+}
+
+static int
+mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
+{
+	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
+
+	if (value)
+		return mlxreg_led_store_hw(led_data, led_data->base_color);
+	else
+		return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF);
+}
+
+static enum led_brightness
+mlxreg_led_brightness_get(struct led_classdev *cled)
+{
+	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
+
+	return mlxreg_led_get_hw(led_data);
+}
+
+static int
+mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
+		     unsigned long *delay_off)
+{
+	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
+	int err;
+
+	/*
+	 * HW supports two types of blinking: full (6Hz) and half (3Hz).
+	 * For delay on/off zero LED is setting to solid color. For others
+	 * combination blinking is to be controlled by the software timer.
+	 */
+	if (!(*delay_on == 0 && *delay_off == 0) &&
+	    !(*delay_on == MLXREG_LED_BLINK_3HZ &&
+	      *delay_off == MLXREG_LED_BLINK_3HZ) &&
+	    !(*delay_on == MLXREG_LED_BLINK_6HZ &&
+	      *delay_off == MLXREG_LED_BLINK_6HZ))
+		return -EINVAL;
+
+	if (*delay_on == MLXREG_LED_BLINK_6HZ)
+		err = mlxreg_led_store_hw(led_data, led_data->base_color +
+					  MLXREG_LED_OFFSET_BLINK_6HZ);
+	else if (*delay_on == MLXREG_LED_BLINK_3HZ)
+		err = mlxreg_led_store_hw(led_data, led_data->base_color +
+					  MLXREG_LED_OFFSET_BLINK_3HZ);
+	else
+		err = mlxreg_led_store_hw(led_data, led_data->base_color);
+
+	return err;
+}
+
+static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
+{
+	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
+	struct mlxreg_core_data *data = led_pdata->data;
+	struct mlxreg_led_data *led_data;
+	struct led_classdev *led_cdev;
+	int brightness;
+	int i;
+	int err;
+
+	for (i = 0; i < led_pdata->counter; i++, data++) {
+		led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
+					GFP_KERNEL);
+		if (!led_data)
+			return -ENOMEM;
+
+		led_cdev = &led_data->led_cdev;
+		led_data->data_parent = priv;
+		if (strstr(data->label, "red") ||
+		    strstr(data->label, "orange")) {
+			brightness = LED_OFF;
+			led_data->base_color = MLXREG_LED_RED_SOLID;
+		} else if (strstr(data->label, "amber")) {
+			brightness = LED_OFF;
+			led_data->base_color = MLXREG_LED_AMBER_SOLID;
+		} else {
+			brightness = LED_OFF;
+			led_data->base_color = MLXREG_LED_GREEN_SOLID;
+		}
+		sprintf(led_data->led_cdev_name, "%s:%s", "mlxreg",
+			data->label);
+		led_cdev->name = led_data->led_cdev_name;
+		led_cdev->brightness = brightness;
+		led_cdev->max_brightness = LED_ON;
+		led_cdev->brightness_set_blocking =
+						mlxreg_led_brightness_set;
+		led_cdev->brightness_get = mlxreg_led_brightness_get;
+		led_cdev->blink_set = mlxreg_led_blink_set;
+		led_cdev->flags = LED_CORE_SUSPENDRESUME;
+		led_data->data = data;
+		err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
+		if (err)
+			return err;
+
+		if (led_cdev->brightness)
+			mlxreg_led_brightness_set(led_cdev,
+						  led_cdev->brightness);
+		dev_info(led_cdev->dev, "label: %s, mask: 0x%02x, offset:0x%02x\n",
+			 data->label, data->mask, data->reg);
+	}
+
+	return 0;
+}
+
+static int mlxreg_led_probe(struct platform_device *pdev)
+{
+	struct mlxreg_core_platform_data *led_pdata;
+	struct mlxreg_led_priv_data *priv;
+
+	led_pdata = dev_get_platdata(&pdev->dev);
+	if (!led_pdata) {
+		dev_err(&pdev->dev, "Failed to get platform data.\n");
+		return -EINVAL;
+	}
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mutex_init(&priv->access_lock);
+	priv->pdev = pdev;
+	priv->pdata = led_pdata;
+
+	return mlxreg_led_config(priv);
+}
+
+static int mlxreg_led_remove(struct platform_device *pdev)
+{
+	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
+
+	mutex_destroy(&priv->access_lock);
+
+	return 0;
+}
+
+static struct platform_driver mlxreg_led_driver = {
+	.driver = {
+	    .name = "leds-mlxreg",
+	},
+	.probe = mlxreg_led_probe,
+	.remove = mlxreg_led_remove,
+};
+
+module_platform_driver(mlxreg_led_driver);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox LED regmap driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:leds-mlxreg");
-- 
2.1.4

Re: [patch v6 1/1] leds: add driver for support Mellanox regmap LEDs for BMC and x86 platform

[Jacek Anaszewski]

Hi Vadim,

Thanks for the update.

On 02/12/2018 09:15 PM, Vadim Pasternak wrote:
> Driver obtains LED devices according to system configuration and creates
> devices in form: "devicename:color:function", like
> The full path is to be:
> /sys/class/leds/mlxreg\:status\:amber/brightness
> After timer trigger activation:
> echo timer > /sys/class/leds/mlxreg\:status\:amber/trigger
> Attributes for LED blinking will appaer in sysfs infrastructure:
> /sys/class/leds/mlxreg\:status\:amber/delay_off
> /sys/class/leds/mlxreg\:status\:amber/delay_on
> 
> LED setting is controlled through the on-board programmable devices,
> which exports its register map. This device could be attached to any
> bus type, for which register mapping is supported.
> 
> Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> ---
> v5->v6
>  Changes added by Vadim:
>   - Change year to 2018 in Copyright;
>   - Change structure mlxreg_core_led_platform_data name to common name
>     mlxreg_core_platform_data, as it has been pushed to
>     git://git.infradead.org/linux-platform-drivers-x86.git to branch,
>     commit 1f976f6978bf6156ce822eb279ac86c519b10329 (1f976f6), file
>     include/linux/platform_data/mlxreg.h
>   - Add orange color, as alternative to red (some systems use orange,
>     instead of red);
>   - Drop mlxreg_led_dt_match, since the driver is to be activated by another
>     common Mellanox platform driver, mlx-platform or mlx-platform-of;
> v4->v5
>  Comments pointed out by Jacek:
>  - Make consistent naming in mlxreg_led_brightness_set,
>    mlxreg_led_brightness_get, mlxreg_led_config;
>  - Remove unnecessary data assignment in mlxreg_led_config;
>  Changes added by Vadim:
>  - Add internal structure mlxreg_led_data to leds-mlxreg.c;
> v3->v4
>  Comments pointed out by Jacek:
>  - add led in declaration mlxreg_led_store_hw and mlxreg_led_get_hw;
>  - rearrange local variables names in mlxreg_led_config;
>  Comments pointed out by Pavel:
>  - replace _HALF/_FULL with BLINK_3HZ/BLINK_6HZ;
>  - in mlxreg_led_get_hw just return after access error;
>  - explicit check for green led is not added, since control device can be
>    programmed for blue LED and this case it reuses masks of green LED.
> v2->v3:
>  Comments pointed out by Jacek:
>  - fix order in includes;
>  - add declaration pdata in mlxreg_led_store_hw and mlxreg_led_get_hw;
>  - add declaration of led_data in mlxreg_led_config;
>  - use LED_ON in assignment instead of 1;
>  - fix mutex call in mlxreg_led_remove;
> v1->v2:
>  Comments pointed out by Jacek:
>  - remove macros MLXREG_MAP and MLXREG_CDEV;
>  - brightness_set_blocking insteaf of brightness_set, this fix allows
>    removing of context validation and workqueue and also three fields from
>    struct mlxreg_core_led_data in mlxreg.h;
>  - remove MLXREG_LED_NAME;
>  - extend Kconfig description;
>  Changes added by Vadim:
>  - remove unnecessary includes after dropping workqueue;
> ---
>  MAINTAINERS                |   1 +
>  drivers/leds/Kconfig       |  10 ++
>  drivers/leds/Makefile      |   1 +
>  drivers/leds/leds-mlxreg.c | 311 +++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 323 insertions(+)
>  create mode 100644 drivers/leds/leds-mlxreg.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 95c3fa1..96625b2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8916,6 +8916,7 @@ M:	Vadim Pasternak <vadimp@mellanox.com>
>  L:	linux-leds@vger.kernel.org
>  S:	Supported
>  F:	drivers/leds/leds-mlxcpld.c
> +F:	drivers/leds/leds-mlxreg.c
>  F:	Documentation/leds/leds-mlxcpld.txt
>  
>  MELLANOX PLATFORM DRIVER
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 3e763d2..c98abe1 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -694,6 +694,16 @@ config LEDS_MLXCPLD
>  	  This option enabled support for the LEDs on the Mellanox
>  	  boards. Say Y to enabled these.
>  
> +config LEDS_MLXREG
> +	tristate "LED support for the Mellanox switches management control"
> +	depends on LEDS_CLASS
> +	help
> +	  This option enabled support for the LEDs on the Mellanox Ethernet and

s/enabled/enables/

Just noticed that we have the same typo in two other places in this
Kconfig.

> +	  InfiniBand switches. The driver can be activated from the device tree

You don't seem to use OF API in the driver.

> +	  or by the direct platform device add call.

Could you please explain how it is supposed to work? Who is responsible
for regmap initialization? Do you plan on adding corresponding
platform_data to drivers/platform/x86/mlx-platform.c or so?

> Say Y to enabled these. To
> +	  compile this driver as a module, choose 'M' here: the module will be
> +	  called leds-mlxreg.
> +
>  config LEDS_USER
>  	tristate "Userspace LED support"
>  	depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 987884a..91eca81 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -72,6 +72,7 @@ obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-is31fl319x.o
>  obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
>  obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o
>  obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o
> +obj-$(CONFIG_LEDS_MLXREG)		+= leds-mlxreg.o
>  obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
>  obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
>  obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
> diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
> new file mode 100644
> index 0000000..4dd2bd8
> --- /dev/null
> +++ b/drivers/leds/leds-mlxreg.c
> @@ -0,0 +1,311 @@
> +/*
> + * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the names of the copyright holders nor the names of its
> + *    contributors may be used to endorse or promote products derived from
> + *    this software without specific prior written permission.
> + *
> + * Alternatively, this software may be distributed under the terms of the
> + * GNU General Public License ("GPL") version 2 as published by the Free
> + * Software Foundation.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> + * POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_data/mlxreg.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +/* Codes for LEDs. */
> +#define MLXREG_LED_OFFSET_BLINK_3HZ	0x01 /* Offset from solid: 3Hz blink */
> +#define MLXREG_LED_OFFSET_BLINK_6HZ	0x02 /* Offset from solid: 6Hz blink */
> +#define MLXREG_LED_IS_OFF		0x00 /* Off */
> +#define MLXREG_LED_RED_SOLID		0x05 /* Solid red */
> +#define MLXREG_LED_GREEN_SOLID		0x0D /* Solid green */
> +#define MLXREG_LED_AMBER_SOLID		0x09 /* Solid amber */
> +#define MLXREG_LED_BLINK_3HZ		167 /* ~167 msec off/on - HW support */
> +#define MLXREG_LED_BLINK_6HZ		83 /* ~83 msec off/on - HW support */
> +
> +/**
> + * struct mlxreg_led_data - led control data:
> + *
> + * @data: led configuration data;
> + * @led_classdev: led class data;
> + * @base_color: base led color (other colors have constant offset from base);
> + * @led_data: led data;
> + * @data_parent: pointer to private device control data of parent;
> + */
> +struct mlxreg_led_data {
> +	struct mlxreg_core_data *data;
> +	struct led_classdev led_cdev;
> +	u8 base_color;
> +	void *data_parent;
> +	char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
> +};
> +
> +#define cdev_to_priv(c) container_of(c, struct mlxreg_led_data, led_cdev)
> +
> +/**
> + * struct mlxreg_led_priv_data - platform private data:
> + *
> + * @pdev: platform device;
> + * @pdata: platform data;
> + * @access_lock: mutex for attribute IO access;
> + */
> +struct mlxreg_led_priv_data {
> +	struct platform_device *pdev;
> +	struct mlxreg_core_platform_data *pdata;
> +	struct mutex access_lock; /* protect IO operations */
> +};
> +
> +static int
> +mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset)
> +{
> +	struct mlxreg_led_priv_data *priv = led_data->data_parent;
> +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
> +	struct mlxreg_core_data *data = led_data->data;
> +	u32 regval;
> +	u32 nib;
> +	int ret;
> +
> +	/*
> +	 * Each LED is controlled through low or high nibble of the relevant
> +	 * register byte. Register offset is specified by off parameter.
> +	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
> +	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
> +	 * green.
> +	 * Parameter mask specifies which nibble is used for specific LED: mask
> +	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
> +	 * higher nibble (bits from 4 to 7).
> +	 */
> +	mutex_lock(&priv->access_lock);
> +
> +	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
> +	if (ret)
> +		goto access_error;
> +
> +	nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
> +	      rol32(vset, data->bit + 4);
> +	regval = (regval & data->mask) | nib;
> +
> +	ret = regmap_write(led_pdata->regmap, data->reg, regval);
> +
> +access_error:
> +	mutex_unlock(&priv->access_lock);
> +
> +	return ret;
> +}
> +
> +static enum led_brightness
> +mlxreg_led_get_hw(struct mlxreg_led_data *led_data)
> +{
> +	struct mlxreg_led_priv_data *priv = led_data->data_parent;
> +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
> +	struct mlxreg_core_data *data = led_data->data;
> +	u32 regval;
> +	int ret;
> +
> +	/*
> +	 * Each LED is controlled through low or high nibble of the relevant
> +	 * register byte. Register offset is specified by off parameter.
> +	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
> +	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
> +	 * green.
> +	 * Parameter mask specifies which nibble is used for specific LED: mask
> +	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
> +	 * higher nibble (bits from 4 to 7).
> +	 */
> +	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
> +	if (ret < 0) {
> +		dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
> +			 ret);
> +		/* Assume the LED is OFF */
> +		return LED_OFF;
> +	}
> +
> +	regval = regval & ~data->mask;
> +	regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
> +		 data->bit) : ror32(regval, data->bit + 4);
> +	if (regval >= led_data->base_color &&
> +	    regval <= (led_data->base_color + MLXREG_LED_OFFSET_BLINK_6HZ))
> +		ret = LED_FULL;
> +	else
> +		ret = LED_OFF;
> +
> +	return ret;
> +}
> +
> +static int
> +mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
> +{
> +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
> +
> +	if (value)
> +		return mlxreg_led_store_hw(led_data, led_data->base_color);
> +	else
> +		return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF);
> +}
> +
> +static enum led_brightness
> +mlxreg_led_brightness_get(struct led_classdev *cled)
> +{
> +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
> +
> +	return mlxreg_led_get_hw(led_data);
> +}
> +
> +static int
> +mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
> +		     unsigned long *delay_off)
> +{
> +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
> +	int err;
> +
> +	/*
> +	 * HW supports two types of blinking: full (6Hz) and half (3Hz).
> +	 * For delay on/off zero LED is setting to solid color. For others
> +	 * combination blinking is to be controlled by the software timer.
> +	 */
> +	if (!(*delay_on == 0 && *delay_off == 0) &&
> +	    !(*delay_on == MLXREG_LED_BLINK_3HZ &&
> +	      *delay_off == MLXREG_LED_BLINK_3HZ) &&
> +	    !(*delay_on == MLXREG_LED_BLINK_6HZ &&
> +	      *delay_off == MLXREG_LED_BLINK_6HZ))
> +		return -EINVAL;
> +
> +	if (*delay_on == MLXREG_LED_BLINK_6HZ)
> +		err = mlxreg_led_store_hw(led_data, led_data->base_color +
> +					  MLXREG_LED_OFFSET_BLINK_6HZ);
> +	else if (*delay_on == MLXREG_LED_BLINK_3HZ)
> +		err = mlxreg_led_store_hw(led_data, led_data->base_color +
> +					  MLXREG_LED_OFFSET_BLINK_3HZ);
> +	else
> +		err = mlxreg_led_store_hw(led_data, led_data->base_color);
> +
> +	return err;
> +}
> +
> +static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
> +{
> +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
> +	struct mlxreg_core_data *data = led_pdata->data;
> +	struct mlxreg_led_data *led_data;
> +	struct led_classdev *led_cdev;
> +	int brightness;
> +	int i;
> +	int err;
> +
> +	for (i = 0; i < led_pdata->counter; i++, data++) {
> +		led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
> +					GFP_KERNEL);
> +		if (!led_data)
> +			return -ENOMEM;
> +
> +		led_cdev = &led_data->led_cdev;
> +		led_data->data_parent = priv;
> +		if (strstr(data->label, "red") ||
> +		    strstr(data->label, "orange")) {
> +			brightness = LED_OFF;
> +			led_data->base_color = MLXREG_LED_RED_SOLID;
> +		} else if (strstr(data->label, "amber")) {
> +			brightness = LED_OFF;
> +			led_data->base_color = MLXREG_LED_AMBER_SOLID;
> +		} else {
> +			brightness = LED_OFF;
> +			led_data->base_color = MLXREG_LED_GREEN_SOLID;
> +		}
> +		sprintf(led_data->led_cdev_name, "%s:%s", "mlxreg",
> +			data->label);
> +		led_cdev->name = led_data->led_cdev_name;
> +		led_cdev->brightness = brightness;
> +		led_cdev->max_brightness = LED_ON;
> +		led_cdev->brightness_set_blocking =
> +						mlxreg_led_brightness_set;
> +		led_cdev->brightness_get = mlxreg_led_brightness_get;
> +		led_cdev->blink_set = mlxreg_led_blink_set;
> +		led_cdev->flags = LED_CORE_SUSPENDRESUME;
> +		led_data->data = data;
> +		err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
> +		if (err)
> +			return err;
> +
> +		if (led_cdev->brightness)
> +			mlxreg_led_brightness_set(led_cdev,
> +						  led_cdev->brightness);
> +		dev_info(led_cdev->dev, "label: %s, mask: 0x%02x, offset:0x%02x\n",
> +			 data->label, data->mask, data->reg);
> +	}
> +
> +	return 0;
> +}
> +
> +static int mlxreg_led_probe(struct platform_device *pdev)
> +{
> +	struct mlxreg_core_platform_data *led_pdata;
> +	struct mlxreg_led_priv_data *priv;
> +
> +	led_pdata = dev_get_platdata(&pdev->dev);
> +	if (!led_pdata) {
> +		dev_err(&pdev->dev, "Failed to get platform data.\n");
> +		return -EINVAL;
> +	}
> +
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	mutex_init(&priv->access_lock);
> +	priv->pdev = pdev;
> +	priv->pdata = led_pdata;
> +
> +	return mlxreg_led_config(priv);
> +}
> +
> +static int mlxreg_led_remove(struct platform_device *pdev)
> +{
> +	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
> +
> +	mutex_destroy(&priv->access_lock);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver mlxreg_led_driver = {
> +	.driver = {
> +	    .name = "leds-mlxreg",
> +	},
> +	.probe = mlxreg_led_probe,
> +	.remove = mlxreg_led_remove,
> +};
> +
> +module_platform_driver(mlxreg_led_driver);
> +
> +MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
> +MODULE_DESCRIPTION("Mellanox LED regmap driver");
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_ALIAS("platform:leds-mlxreg");
> 

-- 
Best regards,
Jacek Anaszewski

RE: [patch v6 1/1] leds: add driver for support Mellanox regmap LEDs for BMC and x86 platform

[Vadim Pasternak]

> -----Original Message-----
> From: Jacek Anaszewski [mailto:jacek.anaszewski@gmail.com]
> Sent: Tuesday, February 13, 2018 11:16 PM
> To: Vadim Pasternak <vadimp@mellanox.com>; rpurdie@rpsys.net;
> pavel@ucw.cz
> Cc: linux-leds@vger.kernel.org; jiri@resnulli.us
> Subject: Re: [patch v6 1/1] leds: add driver for support Mellanox regmap LEDs
> for BMC and x86 platform
> 
> Hi Vadim,
> 
> Thanks for the update.

Hi Jacek,

Thank you very much for reply.

> 
> On 02/12/2018 09:15 PM, Vadim Pasternak wrote:
> > Driver obtains LED devices according to system configuration and
> > creates devices in form: "devicename:color:function", like The full
> > path is to be:
> > /sys/class/leds/mlxreg\:status\:amber/brightness
> > After timer trigger activation:
> > echo timer > /sys/class/leds/mlxreg\:status\:amber/trigger
> > Attributes for LED blinking will appaer in sysfs infrastructure:
> > /sys/class/leds/mlxreg\:status\:amber/delay_off
> > /sys/class/leds/mlxreg\:status\:amber/delay_on
> >
> > LED setting is controlled through the on-board programmable devices,
> > which exports its register map. This device could be attached to any
> > bus type, for which register mapping is supported.
> >
> > Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
> > Acked-by: Pavel Machek <pavel@ucw.cz>
> > ---
> > v5->v6
> >  Changes added by Vadim:
> >   - Change year to 2018 in Copyright;
> >   - Change structure mlxreg_core_led_platform_data name to common name
> >     mlxreg_core_platform_data, as it has been pushed to
> >     git://git.infradead.org/linux-platform-drivers-x86.git to branch,
> >     commit 1f976f6978bf6156ce822eb279ac86c519b10329 (1f976f6), file
> >     include/linux/platform_data/mlxreg.h
> >   - Add orange color, as alternative to red (some systems use orange,
> >     instead of red);
> >   - Drop mlxreg_led_dt_match, since the driver is to be activated by another
> >     common Mellanox platform driver, mlx-platform or mlx-platform-of;
> > v4->v5
> >  Comments pointed out by Jacek:
> >  - Make consistent naming in mlxreg_led_brightness_set,
> >    mlxreg_led_brightness_get, mlxreg_led_config;
> >  - Remove unnecessary data assignment in mlxreg_led_config;  Changes
> > added by Vadim:
> >  - Add internal structure mlxreg_led_data to leds-mlxreg.c;
> > v3->v4
> >  Comments pointed out by Jacek:
> >  - add led in declaration mlxreg_led_store_hw and mlxreg_led_get_hw;
> >  - rearrange local variables names in mlxreg_led_config;  Comments
> > pointed out by Pavel:
> >  - replace _HALF/_FULL with BLINK_3HZ/BLINK_6HZ;
> >  - in mlxreg_led_get_hw just return after access error;
> >  - explicit check for green led is not added, since control device can be
> >    programmed for blue LED and this case it reuses masks of green LED.
> > v2->v3:
> >  Comments pointed out by Jacek:
> >  - fix order in includes;
> >  - add declaration pdata in mlxreg_led_store_hw and mlxreg_led_get_hw;
> >  - add declaration of led_data in mlxreg_led_config;
> >  - use LED_ON in assignment instead of 1;
> >  - fix mutex call in mlxreg_led_remove;
> > v1->v2:
> >  Comments pointed out by Jacek:
> >  - remove macros MLXREG_MAP and MLXREG_CDEV;
> >  - brightness_set_blocking insteaf of brightness_set, this fix allows
> >    removing of context validation and workqueue and also three fields from
> >    struct mlxreg_core_led_data in mlxreg.h;
> >  - remove MLXREG_LED_NAME;
> >  - extend Kconfig description;
> >  Changes added by Vadim:
> >  - remove unnecessary includes after dropping workqueue;
> > ---
> >  MAINTAINERS                |   1 +
> >  drivers/leds/Kconfig       |  10 ++
> >  drivers/leds/Makefile      |   1 +
> >  drivers/leds/leds-mlxreg.c | 311
> > +++++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 323 insertions(+)
> >  create mode 100644 drivers/leds/leds-mlxreg.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 95c3fa1..96625b2 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -8916,6 +8916,7 @@ M:	Vadim Pasternak <vadimp@mellanox.com>
> >  L:	linux-leds@vger.kernel.org
> >  S:	Supported
> >  F:	drivers/leds/leds-mlxcpld.c
> > +F:	drivers/leds/leds-mlxreg.c
> >  F:	Documentation/leds/leds-mlxcpld.txt
> >
> >  MELLANOX PLATFORM DRIVER
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index
> > 3e763d2..c98abe1 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -694,6 +694,16 @@ config LEDS_MLXCPLD
> >  	  This option enabled support for the LEDs on the Mellanox
> >  	  boards. Say Y to enabled these.
> >
> > +config LEDS_MLXREG
> > +	tristate "LED support for the Mellanox switches management control"
> > +	depends on LEDS_CLASS
> > +	help
> > +	  This option enabled support for the LEDs on the Mellanox Ethernet
> > +and
> 
> s/enabled/enables/

Ack.
Should I sent a fix for LEDS_MLXCPLD in a separate patch?

> 
> Just noticed that we have the same typo in two other places in this Kconfig.
> 
> > +	  InfiniBand switches. The driver can be activated from the device
> > +tree
> 
> You don't seem to use OF API in the driver.
> 
> > +	  or by the direct platform device add call.
> 
> Could you please explain how it is supposed to work? Who is responsible for
> regmap initialization? Do you plan on adding corresponding platform_data to
> drivers/platform/x86/mlx-platform.c or so?

Yes.
I am going to submit a patch with LED introduction to mlx-platform right
after leds-mlxreg is accepted for the next.
And also I am going to have some kind of mlx-of-platform driver in 
drivers/platform/mellanox for ARM which will use OF API itself.

But you are right, the sentence in Kconfig "The driver can be activated from the device
Tree" is not correct, because even with mlx-of-platform, mlxreg-led driver will not use
OF API by itself.
I'll drop it.

> 
> > Say Y to enabled these. To
> > +	  compile this driver as a module, choose 'M' here: the module will be
> > +	  called leds-mlxreg.
> > +
> >  config LEDS_USER
> >  	tristate "Userspace LED support"
> >  	depends on LEDS_CLASS
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index
> > 987884a..91eca81 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -72,6 +72,7 @@ obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-
> is31fl319x.o
> >  obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
> >  obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o
> >  obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o
> > +obj-$(CONFIG_LEDS_MLXREG)		+= leds-mlxreg.o
> >  obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
> >  obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
> >  obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
> > diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
> > new file mode 100644 index 0000000..4dd2bd8
> > --- /dev/null
> > +++ b/drivers/leds/leds-mlxreg.c
> > @@ -0,0 +1,311 @@
> > +/*
> > + * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
> > + * Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions are
> met:
> > + *
> > + * 1. Redistributions of source code must retain the above copyright
> > + *    notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + *    notice, this list of conditions and the following disclaimer in the
> > + *    documentation and/or other materials provided with the distribution.
> > + * 3. Neither the names of the copyright holders nor the names of its
> > + *    contributors may be used to endorse or promote products derived from
> > + *    this software without specific prior written permission.
> > + *
> > + * Alternatively, this software may be distributed under the terms of
> > +the
> > + * GNU General Public License ("GPL") version 2 as published by the
> > +Free
> > + * Software Foundation.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
> CONTRIBUTORS "AS IS"
> > + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> LIMITED
> > +TO, THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
> PARTICULAR
> > +PURPOSE
> > + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
> > +CONTRIBUTORS BE
> > + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
> > +OR
> > + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
> PROCUREMENT
> > +OF
> > + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> > +BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
> > +WHETHER IN
> > + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
> > +OTHERWISE)
> > + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
> > +ADVISED OF THE
> > + * POSSIBILITY OF SUCH DAMAGE.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/device.h>
> > +#include <linux/io.h>
> > +#include <linux/leds.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/platform_data/mlxreg.h> #include
> > +<linux/platform_device.h> #include <linux/regmap.h>
> > +
> > +/* Codes for LEDs. */
> > +#define MLXREG_LED_OFFSET_BLINK_3HZ	0x01 /* Offset from solid: 3Hz
> blink */
> > +#define MLXREG_LED_OFFSET_BLINK_6HZ	0x02 /* Offset from solid: 6Hz
> blink */
> > +#define MLXREG_LED_IS_OFF		0x00 /* Off */
> > +#define MLXREG_LED_RED_SOLID		0x05 /* Solid red */
> > +#define MLXREG_LED_GREEN_SOLID		0x0D /* Solid green */
> > +#define MLXREG_LED_AMBER_SOLID		0x09 /* Solid amber */
> > +#define MLXREG_LED_BLINK_3HZ		167 /* ~167 msec off/on - HW
> support */
> > +#define MLXREG_LED_BLINK_6HZ		83 /* ~83 msec off/on - HW
> support */
> > +
> > +/**
> > + * struct mlxreg_led_data - led control data:
> > + *
> > + * @data: led configuration data;
> > + * @led_classdev: led class data;
> > + * @base_color: base led color (other colors have constant offset
> > +from base);
> > + * @led_data: led data;
> > + * @data_parent: pointer to private device control data of parent;
> > +*/ struct mlxreg_led_data {
> > +	struct mlxreg_core_data *data;
> > +	struct led_classdev led_cdev;
> > +	u8 base_color;
> > +	void *data_parent;
> > +	char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
> > +};
> > +
> > +#define cdev_to_priv(c) container_of(c, struct mlxreg_led_data,
> > +led_cdev)
> > +
> > +/**
> > + * struct mlxreg_led_priv_data - platform private data:
> > + *
> > + * @pdev: platform device;
> > + * @pdata: platform data;
> > + * @access_lock: mutex for attribute IO access;  */ struct
> > +mlxreg_led_priv_data {
> > +	struct platform_device *pdev;
> > +	struct mlxreg_core_platform_data *pdata;
> > +	struct mutex access_lock; /* protect IO operations */ };
> > +
> > +static int
> > +mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset) {
> > +	struct mlxreg_led_priv_data *priv = led_data->data_parent;
> > +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
> > +	struct mlxreg_core_data *data = led_data->data;
> > +	u32 regval;
> > +	u32 nib;
> > +	int ret;
> > +
> > +	/*
> > +	 * Each LED is controlled through low or high nibble of the relevant
> > +	 * register byte. Register offset is specified by off parameter.
> > +	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
> > +	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
> > +	 * green.
> > +	 * Parameter mask specifies which nibble is used for specific LED: mask
> > +	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
> > +	 * higher nibble (bits from 4 to 7).
> > +	 */
> > +	mutex_lock(&priv->access_lock);
> > +
> > +	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
> > +	if (ret)
> > +		goto access_error;
> > +
> > +	nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
> > +	      rol32(vset, data->bit + 4);
> > +	regval = (regval & data->mask) | nib;
> > +
> > +	ret = regmap_write(led_pdata->regmap, data->reg, regval);
> > +
> > +access_error:
> > +	mutex_unlock(&priv->access_lock);
> > +
> > +	return ret;
> > +}
> > +
> > +static enum led_brightness
> > +mlxreg_led_get_hw(struct mlxreg_led_data *led_data) {
> > +	struct mlxreg_led_priv_data *priv = led_data->data_parent;
> > +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
> > +	struct mlxreg_core_data *data = led_data->data;
> > +	u32 regval;
> > +	int ret;
> > +
> > +	/*
> > +	 * Each LED is controlled through low or high nibble of the relevant
> > +	 * register byte. Register offset is specified by off parameter.
> > +	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
> > +	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
> > +	 * green.
> > +	 * Parameter mask specifies which nibble is used for specific LED: mask
> > +	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
> > +	 * higher nibble (bits from 4 to 7).
> > +	 */
> > +	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
> > +	if (ret < 0) {
> > +		dev_warn(led_data->led_cdev.dev, "Failed to get current
> brightness, error: %d\n",
> > +			 ret);
> > +		/* Assume the LED is OFF */
> > +		return LED_OFF;
> > +	}
> > +
> > +	regval = regval & ~data->mask;
> > +	regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
> > +		 data->bit) : ror32(regval, data->bit + 4);
> > +	if (regval >= led_data->base_color &&
> > +	    regval <= (led_data->base_color +
> MLXREG_LED_OFFSET_BLINK_6HZ))
> > +		ret = LED_FULL;
> > +	else
> > +		ret = LED_OFF;
> > +
> > +	return ret;
> > +}
> > +
> > +static int
> > +mlxreg_led_brightness_set(struct led_classdev *cled, enum
> > +led_brightness value) {
> > +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
> > +
> > +	if (value)
> > +		return mlxreg_led_store_hw(led_data, led_data->base_color);
> > +	else
> > +		return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF); }
> > +
> > +static enum led_brightness
> > +mlxreg_led_brightness_get(struct led_classdev *cled) {
> > +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
> > +
> > +	return mlxreg_led_get_hw(led_data);
> > +}
> > +
> > +static int
> > +mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
> > +		     unsigned long *delay_off)
> > +{
> > +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
> > +	int err;
> > +
> > +	/*
> > +	 * HW supports two types of blinking: full (6Hz) and half (3Hz).
> > +	 * For delay on/off zero LED is setting to solid color. For others
> > +	 * combination blinking is to be controlled by the software timer.
> > +	 */
> > +	if (!(*delay_on == 0 && *delay_off == 0) &&
> > +	    !(*delay_on == MLXREG_LED_BLINK_3HZ &&
> > +	      *delay_off == MLXREG_LED_BLINK_3HZ) &&
> > +	    !(*delay_on == MLXREG_LED_BLINK_6HZ &&
> > +	      *delay_off == MLXREG_LED_BLINK_6HZ))
> > +		return -EINVAL;
> > +
> > +	if (*delay_on == MLXREG_LED_BLINK_6HZ)
> > +		err = mlxreg_led_store_hw(led_data, led_data->base_color +
> > +					  MLXREG_LED_OFFSET_BLINK_6HZ);
> > +	else if (*delay_on == MLXREG_LED_BLINK_3HZ)
> > +		err = mlxreg_led_store_hw(led_data, led_data->base_color +
> > +					  MLXREG_LED_OFFSET_BLINK_3HZ);
> > +	else
> > +		err = mlxreg_led_store_hw(led_data, led_data->base_color);
> > +
> > +	return err;
> > +}
> > +
> > +static int mlxreg_led_config(struct mlxreg_led_priv_data *priv) {
> > +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
> > +	struct mlxreg_core_data *data = led_pdata->data;
> > +	struct mlxreg_led_data *led_data;
> > +	struct led_classdev *led_cdev;
> > +	int brightness;
> > +	int i;
> > +	int err;
> > +
> > +	for (i = 0; i < led_pdata->counter; i++, data++) {
> > +		led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
> > +					GFP_KERNEL);
> > +		if (!led_data)
> > +			return -ENOMEM;
> > +
> > +		led_cdev = &led_data->led_cdev;
> > +		led_data->data_parent = priv;
> > +		if (strstr(data->label, "red") ||
> > +		    strstr(data->label, "orange")) {
> > +			brightness = LED_OFF;
> > +			led_data->base_color = MLXREG_LED_RED_SOLID;
> > +		} else if (strstr(data->label, "amber")) {
> > +			brightness = LED_OFF;
> > +			led_data->base_color = MLXREG_LED_AMBER_SOLID;
> > +		} else {
> > +			brightness = LED_OFF;
> > +			led_data->base_color = MLXREG_LED_GREEN_SOLID;
> > +		}
> > +		sprintf(led_data->led_cdev_name, "%s:%s", "mlxreg",
> > +			data->label);
> > +		led_cdev->name = led_data->led_cdev_name;
> > +		led_cdev->brightness = brightness;
> > +		led_cdev->max_brightness = LED_ON;
> > +		led_cdev->brightness_set_blocking =
> > +						mlxreg_led_brightness_set;
> > +		led_cdev->brightness_get = mlxreg_led_brightness_get;
> > +		led_cdev->blink_set = mlxreg_led_blink_set;
> > +		led_cdev->flags = LED_CORE_SUSPENDRESUME;
> > +		led_data->data = data;
> > +		err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
> > +		if (err)
> > +			return err;
> > +
> > +		if (led_cdev->brightness)
> > +			mlxreg_led_brightness_set(led_cdev,
> > +						  led_cdev->brightness);
> > +		dev_info(led_cdev->dev, "label: %s, mask: 0x%02x,
> offset:0x%02x\n",
> > +			 data->label, data->mask, data->reg);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int mlxreg_led_probe(struct platform_device *pdev) {
> > +	struct mlxreg_core_platform_data *led_pdata;
> > +	struct mlxreg_led_priv_data *priv;
> > +
> > +	led_pdata = dev_get_platdata(&pdev->dev);
> > +	if (!led_pdata) {
> > +		dev_err(&pdev->dev, "Failed to get platform data.\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> > +	if (!priv)
> > +		return -ENOMEM;
> > +
> > +	mutex_init(&priv->access_lock);
> > +	priv->pdev = pdev;
> > +	priv->pdata = led_pdata;
> > +
> > +	return mlxreg_led_config(priv);
> > +}
> > +
> > +static int mlxreg_led_remove(struct platform_device *pdev) {
> > +	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
> > +
> > +	mutex_destroy(&priv->access_lock);
> > +
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver mlxreg_led_driver = {
> > +	.driver = {
> > +	    .name = "leds-mlxreg",
> > +	},
> > +	.probe = mlxreg_led_probe,
> > +	.remove = mlxreg_led_remove,
> > +};
> > +
> > +module_platform_driver(mlxreg_led_driver);
> > +
> > +MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
> > +MODULE_DESCRIPTION("Mellanox LED regmap driver");
> > +MODULE_LICENSE("Dual BSD/GPL"); MODULE_ALIAS("platform:leds-
> mlxreg");
> >
> 
> --
> Best regards,
> Jacek Anaszewski

Thank you,
Vadim.

Re: [patch v6 1/1] leds: add driver for support Mellanox regmap LEDs for BMC and x86 platform

[Jacek Anaszewski]

Hi Vadim,

On 02/13/2018 10:43 PM, Vadim Pasternak wrote:
> 
> 
>> -----Original Message-----
>> From: Jacek Anaszewski [mailto:jacek.anaszewski@gmail.com]
>> Sent: Tuesday, February 13, 2018 11:16 PM
>> To: Vadim Pasternak <vadimp@mellanox.com>; rpurdie@rpsys.net;
>> pavel@ucw.cz
>> Cc: linux-leds@vger.kernel.org; jiri@resnulli.us
>> Subject: Re: [patch v6 1/1] leds: add driver for support Mellanox regmap LEDs
>> for BMC and x86 platform
>>
>> Hi Vadim,
>>
>> Thanks for the update.
> 
> Hi Jacek,
> 
> Thank you very much for reply.

You're welcome.

>>
>> On 02/12/2018 09:15 PM, Vadim Pasternak wrote:
>>> Driver obtains LED devices according to system configuration and
>>> creates devices in form: "devicename:color:function", like The full
>>> path is to be:
>>> /sys/class/leds/mlxreg\:status\:amber/brightness
>>> After timer trigger activation:
>>> echo timer > /sys/class/leds/mlxreg\:status\:amber/trigger
>>> Attributes for LED blinking will appaer in sysfs infrastructure:
>>> /sys/class/leds/mlxreg\:status\:amber/delay_off
>>> /sys/class/leds/mlxreg\:status\:amber/delay_on
>>>
>>> LED setting is controlled through the on-board programmable devices,
>>> which exports its register map. This device could be attached to any
>>> bus type, for which register mapping is supported.
>>>
>>> Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
>>> Acked-by: Pavel Machek <pavel@ucw.cz>
>>> ---
>>> v5->v6
>>>  Changes added by Vadim:
>>>   - Change year to 2018 in Copyright;
>>>   - Change structure mlxreg_core_led_platform_data name to common name
>>>     mlxreg_core_platform_data, as it has been pushed to
>>>     git://git.infradead.org/linux-platform-drivers-x86.git to branch,
>>>     commit 1f976f6978bf6156ce822eb279ac86c519b10329 (1f976f6), file
>>>     include/linux/platform_data/mlxreg.h
>>>   - Add orange color, as alternative to red (some systems use orange,
>>>     instead of red);
>>>   - Drop mlxreg_led_dt_match, since the driver is to be activated by another
>>>     common Mellanox platform driver, mlx-platform or mlx-platform-of;
>>> v4->v5
>>>  Comments pointed out by Jacek:
>>>  - Make consistent naming in mlxreg_led_brightness_set,
>>>    mlxreg_led_brightness_get, mlxreg_led_config;
>>>  - Remove unnecessary data assignment in mlxreg_led_config;  Changes
>>> added by Vadim:
>>>  - Add internal structure mlxreg_led_data to leds-mlxreg.c;
>>> v3->v4
>>>  Comments pointed out by Jacek:
>>>  - add led in declaration mlxreg_led_store_hw and mlxreg_led_get_hw;
>>>  - rearrange local variables names in mlxreg_led_config;  Comments
>>> pointed out by Pavel:
>>>  - replace _HALF/_FULL with BLINK_3HZ/BLINK_6HZ;
>>>  - in mlxreg_led_get_hw just return after access error;
>>>  - explicit check for green led is not added, since control device can be
>>>    programmed for blue LED and this case it reuses masks of green LED.
>>> v2->v3:
>>>  Comments pointed out by Jacek:
>>>  - fix order in includes;
>>>  - add declaration pdata in mlxreg_led_store_hw and mlxreg_led_get_hw;
>>>  - add declaration of led_data in mlxreg_led_config;
>>>  - use LED_ON in assignment instead of 1;
>>>  - fix mutex call in mlxreg_led_remove;
>>> v1->v2:
>>>  Comments pointed out by Jacek:
>>>  - remove macros MLXREG_MAP and MLXREG_CDEV;
>>>  - brightness_set_blocking insteaf of brightness_set, this fix allows
>>>    removing of context validation and workqueue and also three fields from
>>>    struct mlxreg_core_led_data in mlxreg.h;
>>>  - remove MLXREG_LED_NAME;
>>>  - extend Kconfig description;
>>>  Changes added by Vadim:
>>>  - remove unnecessary includes after dropping workqueue;
>>> ---
>>>  MAINTAINERS                |   1 +
>>>  drivers/leds/Kconfig       |  10 ++
>>>  drivers/leds/Makefile      |   1 +
>>>  drivers/leds/leds-mlxreg.c | 311
>>> +++++++++++++++++++++++++++++++++++++++++++++
>>>  4 files changed, 323 insertions(+)
>>>  create mode 100644 drivers/leds/leds-mlxreg.c
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS index 95c3fa1..96625b2 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -8916,6 +8916,7 @@ M:	Vadim Pasternak <vadimp@mellanox.com>
>>>  L:	linux-leds@vger.kernel.org
>>>  S:	Supported
>>>  F:	drivers/leds/leds-mlxcpld.c
>>> +F:	drivers/leds/leds-mlxreg.c
>>>  F:	Documentation/leds/leds-mlxcpld.txt
>>>
>>>  MELLANOX PLATFORM DRIVER
>>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index
>>> 3e763d2..c98abe1 100644
>>> --- a/drivers/leds/Kconfig
>>> +++ b/drivers/leds/Kconfig
>>> @@ -694,6 +694,16 @@ config LEDS_MLXCPLD
>>>  	  This option enabled support for the LEDs on the Mellanox
>>>  	  boards. Say Y to enabled these.
>>>
>>> +config LEDS_MLXREG
>>> +	tristate "LED support for the Mellanox switches management control"
>>> +	depends on LEDS_CLASS
>>> +	help
>>> +	  This option enabled support for the LEDs on the Mellanox Ethernet
>>> +and
>>
>> s/enabled/enables/
> 
> Ack.
> Should I sent a fix for LEDS_MLXCPLD in a separate patch?

Yes please. Would you mind fixing also the same typo for the LED_SYSCON
Kconfig entry in the same patch while we are at it?

>>
>> Just noticed that we have the same typo in two other places in this Kconfig.
>>
>>> +	  InfiniBand switches. The driver can be activated from the device
>>> +tree
>>
>> You don't seem to use OF API in the driver.
>>
>>> +	  or by the direct platform device add call.
>>
>> Could you please explain how it is supposed to work? Who is responsible for
>> regmap initialization? Do you plan on adding corresponding platform_data to
>> drivers/platform/x86/mlx-platform.c or so?
> 
> Yes.
> I am going to submit a patch with LED introduction to mlx-platform right
> after leds-mlxreg is accepted for the next.
> And also I am going to have some kind of mlx-of-platform driver in 
> drivers/platform/mellanox for ARM which will use OF API itself.

You don't have to wait until this patch is merged. You could include
changes to drivers/platform/mellanox in the same patch set and it can
then be merged through an integration branch.

It's of course up to you.

> But you are right, the sentence in Kconfig "The driver can be activated from the device
> Tree" is not correct, because even with mlx-of-platform, mlxreg-led driver will not use
> OF API by itself.
> I'll drop it.

Thanks.

Best regards,
Jacek Anaszewski

>>
>>> Say Y to enabled these. To
>>> +	  compile this driver as a module, choose 'M' here: the module will be
>>> +	  called leds-mlxreg.
>>> +
>>>  config LEDS_USER
>>>  	tristate "Userspace LED support"
>>>  	depends on LEDS_CLASS
>>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index
>>> 987884a..91eca81 100644
>>> --- a/drivers/leds/Makefile
>>> +++ b/drivers/leds/Makefile
>>> @@ -72,6 +72,7 @@ obj-$(CONFIG_LEDS_IS31FL319X)		+= leds-
>> is31fl319x.o
>>>  obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
>>>  obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o
>>>  obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o
>>> +obj-$(CONFIG_LEDS_MLXREG)		+= leds-mlxreg.o
>>>  obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
>>>  obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
>>>  obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
>>> diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
>>> new file mode 100644 index 0000000..4dd2bd8
>>> --- /dev/null
>>> +++ b/drivers/leds/leds-mlxreg.c
>>> @@ -0,0 +1,311 @@
>>> +/*
>>> + * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
>>> + * Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
>>> + *
>>> + * Redistribution and use in source and binary forms, with or without
>>> + * modification, are permitted provided that the following conditions are
>> met:
>>> + *
>>> + * 1. Redistributions of source code must retain the above copyright
>>> + *    notice, this list of conditions and the following disclaimer.
>>> + * 2. Redistributions in binary form must reproduce the above copyright
>>> + *    notice, this list of conditions and the following disclaimer in the
>>> + *    documentation and/or other materials provided with the distribution.
>>> + * 3. Neither the names of the copyright holders nor the names of its
>>> + *    contributors may be used to endorse or promote products derived from
>>> + *    this software without specific prior written permission.
>>> + *
>>> + * Alternatively, this software may be distributed under the terms of
>>> +the
>>> + * GNU General Public License ("GPL") version 2 as published by the
>>> +Free
>>> + * Software Foundation.
>>> + *
>>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
>> CONTRIBUTORS "AS IS"
>>> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> LIMITED
>>> +TO, THE
>>> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
>> PARTICULAR
>>> +PURPOSE
>>> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
>>> +CONTRIBUTORS BE
>>> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
>>> +OR
>>> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
>> PROCUREMENT
>>> +OF
>>> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
>>> +BUSINESS
>>> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
>>> +WHETHER IN
>>> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
>>> +OTHERWISE)
>>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
>>> +ADVISED OF THE
>>> + * POSSIBILITY OF SUCH DAMAGE.
>>> + */
>>> +
>>> +#include <linux/bitops.h>
>>> +#include <linux/device.h>
>>> +#include <linux/io.h>
>>> +#include <linux/leds.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/platform_data/mlxreg.h> #include
>>> +<linux/platform_device.h> #include <linux/regmap.h>
>>> +
>>> +/* Codes for LEDs. */
>>> +#define MLXREG_LED_OFFSET_BLINK_3HZ	0x01 /* Offset from solid: 3Hz
>> blink */
>>> +#define MLXREG_LED_OFFSET_BLINK_6HZ	0x02 /* Offset from solid: 6Hz
>> blink */
>>> +#define MLXREG_LED_IS_OFF		0x00 /* Off */
>>> +#define MLXREG_LED_RED_SOLID		0x05 /* Solid red */
>>> +#define MLXREG_LED_GREEN_SOLID		0x0D /* Solid green */
>>> +#define MLXREG_LED_AMBER_SOLID		0x09 /* Solid amber */
>>> +#define MLXREG_LED_BLINK_3HZ		167 /* ~167 msec off/on - HW
>> support */
>>> +#define MLXREG_LED_BLINK_6HZ		83 /* ~83 msec off/on - HW
>> support */
>>> +
>>> +/**
>>> + * struct mlxreg_led_data - led control data:
>>> + *
>>> + * @data: led configuration data;
>>> + * @led_classdev: led class data;
>>> + * @base_color: base led color (other colors have constant offset
>>> +from base);
>>> + * @led_data: led data;
>>> + * @data_parent: pointer to private device control data of parent;
>>> +*/ struct mlxreg_led_data {
>>> +	struct mlxreg_core_data *data;
>>> +	struct led_classdev led_cdev;
>>> +	u8 base_color;
>>> +	void *data_parent;
>>> +	char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
>>> +};
>>> +
>>> +#define cdev_to_priv(c) container_of(c, struct mlxreg_led_data,
>>> +led_cdev)
>>> +
>>> +/**
>>> + * struct mlxreg_led_priv_data - platform private data:
>>> + *
>>> + * @pdev: platform device;
>>> + * @pdata: platform data;
>>> + * @access_lock: mutex for attribute IO access;  */ struct
>>> +mlxreg_led_priv_data {
>>> +	struct platform_device *pdev;
>>> +	struct mlxreg_core_platform_data *pdata;
>>> +	struct mutex access_lock; /* protect IO operations */ };
>>> +
>>> +static int
>>> +mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset) {
>>> +	struct mlxreg_led_priv_data *priv = led_data->data_parent;
>>> +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
>>> +	struct mlxreg_core_data *data = led_data->data;
>>> +	u32 regval;
>>> +	u32 nib;
>>> +	int ret;
>>> +
>>> +	/*
>>> +	 * Each LED is controlled through low or high nibble of the relevant
>>> +	 * register byte. Register offset is specified by off parameter.
>>> +	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
>>> +	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
>>> +	 * green.
>>> +	 * Parameter mask specifies which nibble is used for specific LED: mask
>>> +	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
>>> +	 * higher nibble (bits from 4 to 7).
>>> +	 */
>>> +	mutex_lock(&priv->access_lock);
>>> +
>>> +	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
>>> +	if (ret)
>>> +		goto access_error;
>>> +
>>> +	nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
>>> +	      rol32(vset, data->bit + 4);
>>> +	regval = (regval & data->mask) | nib;
>>> +
>>> +	ret = regmap_write(led_pdata->regmap, data->reg, regval);
>>> +
>>> +access_error:
>>> +	mutex_unlock(&priv->access_lock);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static enum led_brightness
>>> +mlxreg_led_get_hw(struct mlxreg_led_data *led_data) {
>>> +	struct mlxreg_led_priv_data *priv = led_data->data_parent;
>>> +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
>>> +	struct mlxreg_core_data *data = led_data->data;
>>> +	u32 regval;
>>> +	int ret;
>>> +
>>> +	/*
>>> +	 * Each LED is controlled through low or high nibble of the relevant
>>> +	 * register byte. Register offset is specified by off parameter.
>>> +	 * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
>>> +	 * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
>>> +	 * green.
>>> +	 * Parameter mask specifies which nibble is used for specific LED: mask
>>> +	 * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
>>> +	 * higher nibble (bits from 4 to 7).
>>> +	 */
>>> +	ret = regmap_read(led_pdata->regmap, data->reg, &regval);
>>> +	if (ret < 0) {
>>> +		dev_warn(led_data->led_cdev.dev, "Failed to get current
>> brightness, error: %d\n",
>>> +			 ret);
>>> +		/* Assume the LED is OFF */
>>> +		return LED_OFF;
>>> +	}
>>> +
>>> +	regval = regval & ~data->mask;
>>> +	regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
>>> +		 data->bit) : ror32(regval, data->bit + 4);
>>> +	if (regval >= led_data->base_color &&
>>> +	    regval <= (led_data->base_color +
>> MLXREG_LED_OFFSET_BLINK_6HZ))
>>> +		ret = LED_FULL;
>>> +	else
>>> +		ret = LED_OFF;
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static int
>>> +mlxreg_led_brightness_set(struct led_classdev *cled, enum
>>> +led_brightness value) {
>>> +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
>>> +
>>> +	if (value)
>>> +		return mlxreg_led_store_hw(led_data, led_data->base_color);
>>> +	else
>>> +		return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF); }
>>> +
>>> +static enum led_brightness
>>> +mlxreg_led_brightness_get(struct led_classdev *cled) {
>>> +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
>>> +
>>> +	return mlxreg_led_get_hw(led_data);
>>> +}
>>> +
>>> +static int
>>> +mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
>>> +		     unsigned long *delay_off)
>>> +{
>>> +	struct mlxreg_led_data *led_data = cdev_to_priv(cled);
>>> +	int err;
>>> +
>>> +	/*
>>> +	 * HW supports two types of blinking: full (6Hz) and half (3Hz).
>>> +	 * For delay on/off zero LED is setting to solid color. For others
>>> +	 * combination blinking is to be controlled by the software timer.
>>> +	 */
>>> +	if (!(*delay_on == 0 && *delay_off == 0) &&
>>> +	    !(*delay_on == MLXREG_LED_BLINK_3HZ &&
>>> +	      *delay_off == MLXREG_LED_BLINK_3HZ) &&
>>> +	    !(*delay_on == MLXREG_LED_BLINK_6HZ &&
>>> +	      *delay_off == MLXREG_LED_BLINK_6HZ))
>>> +		return -EINVAL;
>>> +
>>> +	if (*delay_on == MLXREG_LED_BLINK_6HZ)
>>> +		err = mlxreg_led_store_hw(led_data, led_data->base_color +
>>> +					  MLXREG_LED_OFFSET_BLINK_6HZ);
>>> +	else if (*delay_on == MLXREG_LED_BLINK_3HZ)
>>> +		err = mlxreg_led_store_hw(led_data, led_data->base_color +
>>> +					  MLXREG_LED_OFFSET_BLINK_3HZ);
>>> +	else
>>> +		err = mlxreg_led_store_hw(led_data, led_data->base_color);
>>> +
>>> +	return err;
>>> +}
>>> +
>>> +static int mlxreg_led_config(struct mlxreg_led_priv_data *priv) {
>>> +	struct mlxreg_core_platform_data *led_pdata = priv->pdata;
>>> +	struct mlxreg_core_data *data = led_pdata->data;
>>> +	struct mlxreg_led_data *led_data;
>>> +	struct led_classdev *led_cdev;
>>> +	int brightness;
>>> +	int i;
>>> +	int err;
>>> +
>>> +	for (i = 0; i < led_pdata->counter; i++, data++) {
>>> +		led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
>>> +					GFP_KERNEL);
>>> +		if (!led_data)
>>> +			return -ENOMEM;
>>> +
>>> +		led_cdev = &led_data->led_cdev;
>>> +		led_data->data_parent = priv;
>>> +		if (strstr(data->label, "red") ||
>>> +		    strstr(data->label, "orange")) {
>>> +			brightness = LED_OFF;
>>> +			led_data->base_color = MLXREG_LED_RED_SOLID;
>>> +		} else if (strstr(data->label, "amber")) {
>>> +			brightness = LED_OFF;
>>> +			led_data->base_color = MLXREG_LED_AMBER_SOLID;
>>> +		} else {
>>> +			brightness = LED_OFF;
>>> +			led_data->base_color = MLXREG_LED_GREEN_SOLID;
>>> +		}
>>> +		sprintf(led_data->led_cdev_name, "%s:%s", "mlxreg",
>>> +			data->label);
>>> +		led_cdev->name = led_data->led_cdev_name;
>>> +		led_cdev->brightness = brightness;
>>> +		led_cdev->max_brightness = LED_ON;
>>> +		led_cdev->brightness_set_blocking =
>>> +						mlxreg_led_brightness_set;
>>> +		led_cdev->brightness_get = mlxreg_led_brightness_get;
>>> +		led_cdev->blink_set = mlxreg_led_blink_set;
>>> +		led_cdev->flags = LED_CORE_SUSPENDRESUME;
>>> +		led_data->data = data;
>>> +		err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
>>> +		if (err)
>>> +			return err;
>>> +
>>> +		if (led_cdev->brightness)
>>> +			mlxreg_led_brightness_set(led_cdev,
>>> +						  led_cdev->brightness);
>>> +		dev_info(led_cdev->dev, "label: %s, mask: 0x%02x,
>> offset:0x%02x\n",
>>> +			 data->label, data->mask, data->reg);
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int mlxreg_led_probe(struct platform_device *pdev) {
>>> +	struct mlxreg_core_platform_data *led_pdata;
>>> +	struct mlxreg_led_priv_data *priv;
>>> +
>>> +	led_pdata = dev_get_platdata(&pdev->dev);
>>> +	if (!led_pdata) {
>>> +		dev_err(&pdev->dev, "Failed to get platform data.\n");
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>>> +	if (!priv)
>>> +		return -ENOMEM;
>>> +
>>> +	mutex_init(&priv->access_lock);
>>> +	priv->pdev = pdev;
>>> +	priv->pdata = led_pdata;
>>> +
>>> +	return mlxreg_led_config(priv);
>>> +}
>>> +
>>> +static int mlxreg_led_remove(struct platform_device *pdev) {
>>> +	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
>>> +
>>> +	mutex_destroy(&priv->access_lock);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static struct platform_driver mlxreg_led_driver = {
>>> +	.driver = {
>>> +	    .name = "leds-mlxreg",
>>> +	},
>>> +	.probe = mlxreg_led_probe,
>>> +	.remove = mlxreg_led_remove,
>>> +};
>>> +
>>> +module_platform_driver(mlxreg_led_driver);
>>> +
>>> +MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
>>> +MODULE_DESCRIPTION("Mellanox LED regmap driver");
>>> +MODULE_LICENSE("Dual BSD/GPL"); MODULE_ALIAS("platform:leds-
>> mlxreg");
>>>
>>
>> --
>> Best regards,
>> Jacek Anaszewski
> 
> Thank you,
> Vadim.
>