leds: add driver for support Mellanox regmap LEDs for BMC and x86 platform
authorVadim Pasternak <vadimp@mellanox.com>
Thu, 15 Feb 2018 23:37:50 +0000 (23:37 +0000)
committerJacek Anaszewski <jacek.anaszewski@gmail.com>
Mon, 19 Feb 2018 20:09:20 +0000 (21:09 +0100)
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>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
MAINTAINERS
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-mlxreg.c [new file with mode: 0644]

index 3bdc260e36b7a7eaac26003b187c436655fc3412..e458da68948fa2167cb6ec7c8502bea8bc8e30fc 100644 (file)
@@ -9003,6 +9003,7 @@ 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
index 4b95aeda2c012ed90cdb34bdb0b93187b417f2ae..2c896c0e69e1548bfdc9655bd244ce57f72fc554 100644 (file)
@@ -694,6 +694,15 @@ config LEDS_MLXCPLD
          This option enables support for the LEDs on the Mellanox
          boards. Say Y to enable these.
 
+config LEDS_MLXREG
+       tristate "LED support for the Mellanox switches management control"
+       depends on LEDS_CLASS
+       help
+         This option enables support for the LEDs on the Mellanox Ethernet and
+         InfiniBand switches. The driver can be activated by the platform device
+         device add call. Say Y to enable 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
index 987884a5b9a58d0f3bb118f3742b4d9ed18f0609..91eca81cae82780b88461ba6369d6c9d57442920 100644 (file)
@@ -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 (file)
index 0000000..1ee48cb
--- /dev/null
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+//
+// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
+
+#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 err;
+
+       /*
+        * 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).
+        */
+       err = regmap_read(led_pdata->regmap, data->reg, &regval);
+       if (err < 0) {
+               dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
+                        err);
+               /* 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))
+               return LED_FULL;
+
+       return LED_OFF;
+}
+
+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;
+       enum led_brightness 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");