leds: add driver for Mellanox systems LEDs

This makes it possible to create a set of LEDs for Mellanox systems:
"msx6710", "msx6720", "msb7700", "msn2700", "msx1410", "msn2410",
"msb7800", "msn2740", "msn2100".

Driver obtains LED devices according to system configuration, provided
through system DMI data, like mlxcpld:fan1:green, mlxcpld:fan1:red and
creates devices in form: "devicename:colour:function".

LED setting is controlled through on board CPLD Lattice device.
For setting particular LED off, solid, blink:
echo 0 > /sys/class/leds/mlxcpld\:status\:green/brightness
echo 1 > /sys/class/leds/mlxcpld\:status\:green/brightness
echo timer > /sys/class/leds/mlxcpld\:status\:green/trigger

On module probing all LEDs are set green, on removing - off.

Last setting overwrites previous, f.e. sequence for
changing LED from green - red - green:
echo 1 > /sys/class/leds/mlxcpld\:psu\:green/brightness
echo 1 > /sys/class/leds/mlxcpld\:psu\:red/brightness
echo 1 > /sys/class/leds/mlxcpld\:psu\:green/brightness
Note: LEDs cannot be turned on/off simultaneously.

The Kconfig currently controlling compilation of this code is:
drivers/leds/Kconfig:config LEDS_MLXCPLD

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

3 files changed, 439 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 969c720dfd10..7a628c6516f6 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -651,6 +651,14 @@ config LEDS_PM8058
 	  Choose this option if you want to use the LED drivers in
 	  the Qualcomm PM8058 PMIC.
 
+config LEDS_MLXCPLD
+	tristate "LED support for the Mellanox boards"
+	depends on X86_64 && DMI
+	depends on LEDS_CLASS
+	help
+	  This option enabled support for the LEDs on the Mellanox
+	  boards. Say Y to enabled these.
+
 comment "LED Triggers"
 source "drivers/leds/trigger/Kconfig"
 
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 06a27ef17554..3965070190f5 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_LEDS_SEAD3)		+= leds-sead3.o
 obj-$(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
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
diff --git a/drivers/leds/leds-mlxcpld.c b/drivers/leds/leds-mlxcpld.c
new file mode 100644
index 000000000000..197ab9b29a9c
--- /dev/null
+++ b/drivers/leds/leds-mlxcpld.c
@@ -0,0 +1,430 @@
+/*
+ * drivers/leds/leds-mlxcpld.c
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016 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/acpi.h>
+#include <linux/device.h>
+#include <linux/dmi.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/io.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define MLXPLAT_CPLD_LPC_REG_BASE_ADRR     0x2500 /* LPC bus access */
+
+/* Color codes for LEDs */
+#define MLXCPLD_LED_OFFSET_HALF		0x01 /* Offset from solid: 3Hz blink */
+#define MLXCPLD_LED_OFFSET_FULL		0x02 /* Offset from solid: 6Hz blink */
+#define MLXCPLD_LED_IS_OFF		0x00 /* Off */
+#define MLXCPLD_LED_RED_STATIC_ON	0x05 /* Solid red */
+#define MLXCPLD_LED_RED_BLINK_HALF	(MLXCPLD_LED_RED_STATIC_ON + \
+					 MLXCPLD_LED_OFFSET_HALF)
+#define MLXCPLD_LED_RED_BLINK_FULL	(MLXCPLD_LED_RED_STATIC_ON + \
+					 MLXCPLD_LED_OFFSET_FULL)
+#define MLXCPLD_LED_GREEN_STATIC_ON	0x0D /* Solid green */
+#define MLXCPLD_LED_GREEN_BLINK_HALF	(MLXCPLD_LED_GREEN_STATIC_ON + \
+					 MLXCPLD_LED_OFFSET_HALF)
+#define MLXCPLD_LED_GREEN_BLINK_FULL	(MLXCPLD_LED_GREEN_STATIC_ON + \
+					 MLXCPLD_LED_OFFSET_FULL)
+#define MLXCPLD_LED_BLINK_3HZ		167 /* ~167 msec off/on */
+#define MLXCPLD_LED_BLINK_6HZ		83 /* ~83 msec off/on */
+
+/**
+ * mlxcpld_param - LED access parameters:
+ * @offset - offset for LED access in CPLD device
+ * @mask - mask for LED access in CPLD device
+ * @base_color - base color code for LED
+**/
+struct mlxcpld_param {
+	u8 offset;
+	u8 mask;
+	u8 base_color;
+};
+
+/**
+ * mlxcpld_led_priv - LED private data:
+ * @cled - LED class device instance
+ * @param - LED CPLD access parameters
+**/
+struct mlxcpld_led_priv {
+	struct led_classdev cdev;
+	struct mlxcpld_param param;
+};
+
+#define cdev_to_priv(c)		container_of(c, struct mlxcpld_led_priv, cdev)
+
+/**
+ * mlxcpld_led_profile - system LED profile (defined per system class):
+ * @offset - offset for LED access in CPLD device
+ * @mask - mask for LED access in CPLD device
+ * @base_color - base color code
+ * @brightness - default brightness setting (on/off)
+ * @name - LED name
+**/
+struct mlxcpld_led_profile {
+	u8 offset;
+	u8 mask;
+	u8 base_color;
+	enum led_brightness brightness;
+	const char *name;
+};
+
+/**
+ * mlxcpld_led_pdata - system LED private data
+ * @pdev - platform device pointer
+ * @pled - LED class device instance
+ * @profile - system configuration profile
+ * @num_led_instances - number of LED instances
+ * @lock - device access lock
+**/
+struct mlxcpld_led_pdata {
+	struct platform_device *pdev;
+	struct mlxcpld_led_priv *pled;
+	struct mlxcpld_led_profile *profile;
+	int num_led_instances;
+	spinlock_t lock;
+};
+
+static struct mlxcpld_led_pdata *mlxcpld_led;
+
+/* Default profile fit the next Mellanox systems:
+ * "msx6710", "msx6720", "msb7700", "msn2700", "msx1410",
+ * "msn2410", "msb7800", "msn2740"
+ */
+static struct mlxcpld_led_profile mlxcpld_led_default_profile[] = {
+	{
+		0x21, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:fan1:green",
+	},
+	{
+		0x21, 0xf0, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:fan1:red",
+	},
+	{
+		0x21, 0x0f, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:fan2:green",
+	},
+	{
+		0x21, 0x0f, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:fan2:red",
+	},
+	{
+		0x22, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:fan3:green",
+	},
+	{
+		0x22, 0xf0, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:fan3:red",
+	},
+	{
+		0x22, 0x0f, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:fan4:green",
+	},
+	{
+		0x22, 0x0f, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:fan4:red",
+	},
+	{
+		0x20, 0x0f, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:psu:green",
+	},
+	{
+		0x20, 0x0f, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:psu:red",
+	},
+	{
+		0x20, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:status:green",
+	},
+	{
+		0x20, 0xf0, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:status:red",
+	},
+};
+
+/* Profile fit the Mellanox systems based on "msn2100" */
+static struct mlxcpld_led_profile mlxcpld_led_msn2100_profile[] = {
+	{
+		0x21, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:fan:green",
+	},
+	{
+		0x21, 0xf0, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:fan:red",
+	},
+	{
+		0x23, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:psu1:green",
+	},
+	{
+		0x23, 0xf0, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:psu1:red",
+	},
+	{
+		0x23, 0x0f, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:psu2:green",
+	},
+	{
+		0x23, 0x0f, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:psu2:red",
+	},
+	{
+		0x20, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, 1,
+		"mlxcpld:status:green",
+	},
+	{
+		0x20, 0xf0, MLXCPLD_LED_RED_STATIC_ON, LED_OFF,
+		"mlxcpld:status:red",
+	},
+	{
+		0x24, 0xf0, MLXCPLD_LED_GREEN_STATIC_ON, LED_OFF,
+		"mlxcpld:uid:blue",
+	},
+};
+
+enum mlxcpld_led_platform_types {
+	MLXCPLD_LED_PLATFORM_DEFAULT,
+	MLXCPLD_LED_PLATFORM_MSN2100,
+};
+
+static const char *mlx_product_names[] = {
+	"DEFAULT",
+	"MSN2100",
+};
+
+static enum
+mlxcpld_led_platform_types mlxcpld_led_platform_check_sys_type(void)
+{
+	const char *mlx_product_name;
+	int i;
+
+	mlx_product_name = dmi_get_system_info(DMI_PRODUCT_NAME);
+	if (!mlx_product_name)
+		return MLXCPLD_LED_PLATFORM_DEFAULT;
+
+	for (i = 1;  i < ARRAY_SIZE(mlx_product_names); i++) {
+		if (strstr(mlx_product_name, mlx_product_names[i]))
+			return i;
+	}
+
+	return MLXCPLD_LED_PLATFORM_DEFAULT;
+}
+
+static void mlxcpld_led_bus_access_func(u16 base, u8 offset, u8 rw_flag,
+					u8 *data)
+{
+	u32 addr = base + offset;
+
+	if (rw_flag == 0)
+		outb(*data, addr);
+	else
+		*data = inb(addr);
+}
+
+static void mlxcpld_led_store_hw(u8 mask, u8 off, u8 vset)
+{
+	u8 nib, val;
+
+	/*
+	 * Each LED is controlled through low or high nibble of the relevant
+	 * CPLD register. 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).
+	 */
+	spin_lock(&mlxcpld_led->lock);
+	mlxcpld_led_bus_access_func(MLXPLAT_CPLD_LPC_REG_BASE_ADRR, off, 1,
+				    &val);
+	nib = (mask == 0xf0) ? vset : (vset << 4);
+	val = (val & mask) | nib;
+	mlxcpld_led_bus_access_func(MLXPLAT_CPLD_LPC_REG_BASE_ADRR, off, 0,
+				    &val);
+	spin_unlock(&mlxcpld_led->lock);
+}
+
+static void mlxcpld_led_brightness_set(struct led_classdev *led,
+				       enum led_brightness value)
+{
+	struct mlxcpld_led_priv *pled = cdev_to_priv(led);
+
+	if (value) {
+		mlxcpld_led_store_hw(pled->param.mask, pled->param.offset,
+				     pled->param.base_color);
+		return;
+	}
+
+	mlxcpld_led_store_hw(pled->param.mask, pled->param.offset,
+			     MLXCPLD_LED_IS_OFF);
+}
+
+static int mlxcpld_led_blink_set(struct led_classdev *led,
+				 unsigned long *delay_on,
+				 unsigned long *delay_off)
+{
+	struct mlxcpld_led_priv *pled = cdev_to_priv(led);
+
+	/*
+	 * HW supports two types of blinking: full (6Hz) and half (3Hz).
+	 * For delay on/off zero default setting 3Hz is used.
+	 */
+	if (!(*delay_on == 0 && *delay_off == 0) &&
+	    !(*delay_on == MLXCPLD_LED_BLINK_3HZ &&
+	      *delay_off == MLXCPLD_LED_BLINK_3HZ) &&
+	    !(*delay_on == MLXCPLD_LED_BLINK_6HZ &&
+	      *delay_off == MLXCPLD_LED_BLINK_6HZ))
+		return -EINVAL;
+
+	if (*delay_on == MLXCPLD_LED_BLINK_6HZ)
+		mlxcpld_led_store_hw(pled->param.mask, pled->param.offset,
+				     pled->param.base_color +
+				     MLXCPLD_LED_OFFSET_FULL);
+	else
+		mlxcpld_led_store_hw(pled->param.mask, pled->param.offset,
+				     pled->param.base_color +
+				     MLXCPLD_LED_OFFSET_HALF);
+
+	return 0;
+}
+
+static int mlxcpld_led_config(struct device *dev,
+			      struct mlxcpld_led_pdata *cpld)
+{
+	int i;
+	int err;
+
+	cpld->pled = devm_kzalloc(dev, sizeof(struct mlxcpld_led_priv) *
+				  cpld->num_led_instances, GFP_KERNEL);
+	if (!cpld->pled)
+		return -ENOMEM;
+
+	for (i = 0; i < cpld->num_led_instances; i++) {
+		cpld->pled[i].cdev.name = cpld->profile[i].name;
+		cpld->pled[i].cdev.brightness = cpld->profile[i].brightness;
+		cpld->pled[i].cdev.max_brightness = 1;
+		cpld->pled[i].cdev.brightness_set = mlxcpld_led_brightness_set;
+		cpld->pled[i].cdev.blink_set = mlxcpld_led_blink_set;
+		cpld->pled[i].cdev.flags = LED_CORE_SUSPENDRESUME;
+		err = devm_led_classdev_register(dev, &cpld->pled[i].cdev);
+		if (err)
+			return err;
+
+		cpld->pled[i].param.offset = mlxcpld_led->profile[i].offset;
+		cpld->pled[i].param.mask = mlxcpld_led->profile[i].mask;
+		cpld->pled[i].param.base_color =
+					mlxcpld_led->profile[i].base_color;
+
+		if (mlxcpld_led->profile[i].brightness)
+			mlxcpld_led_brightness_set(&cpld->pled[i].cdev,
+					mlxcpld_led->profile[i].brightness);
+	}
+
+	return 0;
+}
+
+static int __init mlxcpld_led_probe(struct platform_device *pdev)
+{
+	enum mlxcpld_led_platform_types mlxcpld_led_plat =
+					mlxcpld_led_platform_check_sys_type();
+
+	mlxcpld_led = devm_kzalloc(&pdev->dev, sizeof(*mlxcpld_led),
+				   GFP_KERNEL);
+	if (!mlxcpld_led)
+		return -ENOMEM;
+
+	mlxcpld_led->pdev = pdev;
+
+	switch (mlxcpld_led_plat) {
+	case MLXCPLD_LED_PLATFORM_MSN2100:
+		mlxcpld_led->profile = mlxcpld_led_msn2100_profile;
+		mlxcpld_led->num_led_instances =
+				ARRAY_SIZE(mlxcpld_led_msn2100_profile);
+		break;
+
+	default:
+		mlxcpld_led->profile = mlxcpld_led_default_profile;
+		mlxcpld_led->num_led_instances =
+				ARRAY_SIZE(mlxcpld_led_default_profile);
+		break;
+	}
+
+	spin_lock_init(&mlxcpld_led->lock);
+
+	return mlxcpld_led_config(&pdev->dev, mlxcpld_led);
+}
+
+static struct platform_driver mlxcpld_led_driver = {
+	.driver = {
+		.name	= KBUILD_MODNAME,
+	},
+};
+
+static int __init mlxcpld_led_init(void)
+{
+	struct platform_device *pdev;
+	int err;
+
+	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		pr_err("Device allocation failed\n");
+		return PTR_ERR(pdev);
+	}
+
+	err = platform_driver_probe(&mlxcpld_led_driver, mlxcpld_led_probe);
+	if (err) {
+		pr_err("Probe platform driver failed\n");
+		platform_device_unregister(pdev);
+	}
+
+	return err;
+}
+
+static void __exit mlxcpld_led_exit(void)
+{
+	platform_device_unregister(mlxcpld_led->pdev);
+	platform_driver_unregister(&mlxcpld_led_driver);
+}
+
+module_init(mlxcpld_led_init);
+module_exit(mlxcpld_led_exit);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox board LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds_mlxcpld");