Adding initial GPIO LED driver for Edison

This is an initial GPIO LED driver for the Edison
Brillo project. It will likely be replaced with a
far more functional driver, but this will unblock
end customer wishing to test userspace applications
and associated HAL.

Change-Id: Ib7942b2f8df1f3b298a2a766d0b833168ac407c2
Signed-off-by: Brian Wood <brian.j.wood@intel.com>

6 files changed, 291 insertions, 1 deletions

diff --git a/arch/x86/configs/i386_brillo_edison_defconfig b/arch/x86/configs/i386_brillo_edison_defconfig
index 0b129bded66..9add69cafd8 100644
--- a/arch/x86/configs/i386_brillo_edison_defconfig
+++ b/arch/x86/configs/i386_brillo_edison_defconfig
@@ -2828,7 +2828,7 @@ CONFIG_LEDS_CLASS=y
 # CONFIG_LEDS_LM3530 is not set
 # CONFIG_LEDS_LM3642 is not set
 # CONFIG_LEDS_PCA9532 is not set
-# CONFIG_LEDS_GPIO is not set
+CONFIG_LEDS_GPIO=y
 # CONFIG_LEDS_LP3944 is not set
 # CONFIG_LEDS_LP5521 is not set
 # CONFIG_LEDS_LP5523 is not set
@@ -2840,6 +2840,7 @@ CONFIG_LEDS_CLASS=y
 # CONFIG_LEDS_REGULATOR is not set
 # CONFIG_LEDS_BD2802 is not set
 # CONFIG_LEDS_INTEL_SS4200 is not set
+CONFIG_LEDS_INTEL_GPIO_FLASH=y
 # CONFIG_LEDS_LT3593 is not set
 # CONFIG_LEDS_TCA6507 is not set
 # CONFIG_LEDS_LM355x is not set
diff --git a/arch/x86/platform/intel-mid/device_libs/Makefile b/arch/x86/platform/intel-mid/device_libs/Makefile
index 20b06c5bed9..7881b06cadd 100644
--- a/arch/x86/platform/intel-mid/device_libs/Makefile
+++ b/arch/x86/platform/intel-mid/device_libs/Makefile
@@ -44,6 +44,7 @@ obj-$(subst m,y,$(CONFIG_SPI_SPIDEV)) += platform_spidev.o
 obj-$(subst m,y,$(CONFIG_TI_ADS7955_ADC)) += platform_ads7955.o
 # MISC Devices
 obj-$(subst m,y,$(CONFIG_KEYBOARD_GPIO)) += platform_gpio_keys.o
+obj-$(subst m,y,$(CONFIG_LEDS_INTEL_GPIO_FLASH)) += platform_gpio_leds.o
 obj-$(subst m,y,$(CONFIG_INTEL_MID_WATCHDOG)) += platform_wdt.o
 # ADC
 obj-$(subst m,y,$(CONFIG_MSIC_GPADC))	+= platform_msic_adc.o
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_gpio_leds.c b/arch/x86/platform/intel-mid/device_libs/platform_gpio_leds.c
new file mode 100644
index 00000000000..00ea922bc19
--- /dev/null
+++ b/arch/x86/platform/intel-mid/device_libs/platform_gpio_leds.c
@@ -0,0 +1,30 @@
+/*
+ * platform_gpio_leds.c: gpio_leds platform data initilization file
+ *
+ * (C) Copyright 2015 Intel Corporation
+ * Author:
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <asm/intel-mid.h>
+
+
+static struct platform_device led_dev = {
+	.name = "leds-edison-gpio-flash",
+	.id = -1,
+};
+
+static int __init leds_gpio_init(void)
+{
+	pr_info("%s: Registering Intel LED GPIO platform device\n", __func__);
+	return platform_device_register(&led_dev);
+}
+
+rootfs_initcall(leds_gpio_init);
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ef992293598..d5de750a515 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -359,6 +359,15 @@ config LEDS_INTEL_SS4200
 	  drive or power LEDs on the front panel.  Using this driver
 	  can stop the front LED from blinking after startup.
 
+config LEDS_INTEL_GPIO_FLASH
+	tristate "Support for GPIO Flash LEDs"
+	help
+	  This driver supports the leds functionality of GPIO Flash LED. It
+	  includes flash mode and torch mode.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called leds-gpio-flash.
+
 config LEDS_LT3593
 	tristate "LED driver for LT3593 controllers"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index ac2897732b0..7bdf86f67da 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_LEDS_WM8350)		+= leds-wm8350.o
 obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
 obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o
 obj-$(CONFIG_LEDS_INTEL_SS4200)		+= leds-ss4200.o
+obj-$(CONFIG_LEDS_INTEL_GPIO_FLASH)	+= leds-edison-gpio-flash.o
 obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
 obj-$(CONFIG_LEDS_ADP5520)		+= leds-adp5520.o
 obj-$(CONFIG_LEDS_DELL_NETBOOKS)	+= dell-led.o
diff --git a/drivers/leds/leds-edison-gpio-flash.c b/drivers/leds/leds-edison-gpio-flash.c
new file mode 100644
index 00000000000..8363212c610
--- /dev/null
+++ b/drivers/leds/leds-edison-gpio-flash.c
@@ -0,0 +1,248 @@
+
+/* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * (C) Copyright 2015 Intel Corporation
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/printk.h>
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+
+/* #define CONFIG_GPIO_FLASH_DEBUG */
+#undef CDBG
+#ifdef CONFIG_GPIO_FLASH_DEBUG
+#define CDBG(fmt, args...) pr_err(fmt, ##args)
+#else
+#define CDBG(fmt, args...) do { } while (0)
+#endif
+
+#define LED_GPIO_FLASH_DRIVER_NAME	"leds-edison-gpio-flash"
+#define LED_TRIGGER_DEFAULT		"none"
+
+#define GPIO_PIN_NUM 		243	/* temporary hardcoded value for development */
+#define GPIO_PIN_MUX_NUM 	261     /* "     "         "       "         "     " */
+#define GPIO_LABEL 		"DS2"
+#define GPIO_LABEL_MUX 		"DS2_MUX"
+
+#define GPIO_OUT_LOW          (0 << 1)
+#define GPIO_OUT_HIGH         (1 << 1)
+
+struct led_gpio_flash_data {
+	struct led_classdev cdev;
+	int gpio_pin_num;	/* record single GPIO number, hard coded value for now (will change) */
+	int gpio_pin_mux_num;
+	int gpio_value;		/* record single GPIO value on/off -> 1/0 */
+	struct work_struct	led_flash_work;
+};
+
+/* Workqueue handler function */
+static void ledwq_work_handler(struct work_struct *ws)
+{
+	pr_debug("%s: Use the workqueue for flashing the LED\n", __func__);
+	int ret = 0;
+	struct led_gpio_flash_data *flash_led =
+		container_of(ws, struct led_gpio_flash_data, led_flash_work);
+	while(1) {
+		if (ret) {
+			pr_debug("ON\n");
+			gpio_set_value_cansleep(flash_led->gpio_pin_num, 0);
+			ret = 0;
+		} else { /* ret == 0 */
+			pr_debug("OFF\n");
+			gpio_set_value_cansleep(flash_led->gpio_pin_num, 1);
+			ret = 1;
+		}
+		pr_debug("Delay \n");
+		mdelay(10000/(flash_led->cdev.brightness+1));
+		if (flash_led->cdev.brightness == LED_OFF ||
+			flash_led->cdev.brightness == LED_FULL)
+			break;
+	}
+}
+
+static void led_gpio_brightness_set(struct led_classdev *led_cdev,
+				    enum led_brightness value)
+{
+	struct led_gpio_flash_data *flash_led =
+	    container_of(led_cdev, struct led_gpio_flash_data, cdev);
+	int brightness = value;
+
+	if (brightness >= 255) { /* Turn on LED */		
+		pr_debug("%s: Turning on LED, brightness=%d\n", __func__, brightness);
+		gpio_set_value_cansleep(flash_led->gpio_pin_num, 0);
+		if (gpio_get_value_cansleep(flash_led->gpio_pin_num)) { /* if 0 we failed to set */
+			pr_err("%s: Failed to set gpio %d\n", __func__,
+				flash_led->gpio_pin_num);
+			goto err;
+		}
+		flash_led->gpio_value = gpio_get_value_cansleep(flash_led->gpio_pin_num);
+		pr_debug("%s: GPIO value=%d\n", __func__, flash_led->gpio_value);
+        } else if (brightness <= 0) { /* Turn off LED */
+		pr_debug("%s: Turning off LED, brightness=%d\n", __func__, brightness);
+		gpio_set_value_cansleep(flash_led->gpio_pin_num, 1);
+		if (gpio_get_value_cansleep(flash_led->gpio_pin_num)) { /* if nonzero we failed to set */
+			pr_err("%s: Failed to set gpio %d\n", __func__,
+				flash_led->gpio_pin_num);
+			goto err;
+		}
+		flash_led->gpio_value = gpio_get_value_cansleep(flash_led->gpio_pin_num);
+		pr_debug("%s: GPIO value=%d\n", __func__, flash_led->gpio_value);
+        } else { /* Use the workqueue for flashing the LED */
+		pr_debug("%s: Prepare and queue work\n", __func__);
+		schedule_work(&flash_led->led_flash_work);
+	}
+
+	flash_led->cdev.brightness = brightness;
+	pr_debug("%s: Stored new value for brightness=%d\n", __func__, flash_led->cdev.brightness);
+err:
+	return;
+}
+
+static enum led_brightness led_gpio_brightness_get(struct led_classdev
+						   *led_cdev)
+{
+	struct led_gpio_flash_data *flash_led =
+	    container_of(led_cdev, struct led_gpio_flash_data, cdev);
+	pr_debug("%s: returning brightness=%d\n", __func__, flash_led->cdev.brightness);
+	return flash_led->cdev.brightness;
+}
+
+int led_gpio_flash_probe(struct platform_device *pdev)
+{
+	int rc = 0;
+	struct led_gpio_flash_data *flash_led = NULL;
+	
+	dev_info(&pdev->dev, "%s: enter probe\n", __func__);
+	flash_led = devm_kzalloc(&pdev->dev, sizeof(struct led_gpio_flash_data),
+				 GFP_KERNEL);
+	if (flash_led == NULL) {
+		dev_err(&pdev->dev, "%s:%d Unable to allocate memory\n",
+			__func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	INIT_WORK(&flash_led->led_flash_work, ledwq_work_handler);
+	flash_led->gpio_pin_num = GPIO_PIN_NUM;
+	flash_led->gpio_pin_mux_num = GPIO_PIN_MUX_NUM;
+	flash_led->cdev.default_trigger = LED_TRIGGER_DEFAULT;
+	dev_info(&pdev->dev, "%s: GPIO LED number=%d, GPIO LED pin mux number=%d, "
+		"default trigger=%s\n", __func__, flash_led->gpio_pin_num,
+		flash_led->gpio_pin_mux_num, flash_led->cdev.default_trigger);
+
+	/* Request the output enable pinmux for the DS2 LED GPIO */
+	rc = gpio_request(flash_led->gpio_pin_mux_num, GPIO_LABEL_MUX);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: Failed to request gpio %d,rc = %d\n",
+			 __func__, flash_led->gpio_pin_mux_num, rc);
+		goto error;
+	}
+	rc = gpio_direction_output(flash_led->gpio_pin_mux_num, 0); /* Make sure the direction is out */
+	if (rc)
+		dev_info(&pdev->dev, "%s: Setting GPIO %d direction to out failed!, rc=%d\n",
+			__func__, flash_led->gpio_pin_mux_num, rc);
+	else
+		dev_info(&pdev->dev, "%s: Setting GPIO %d direction to out succeeded, "
+			"rc=%d.\n", __func__, flash_led->gpio_pin_mux_num, rc);
+
+	/* Request the DS2 LED GPIO */
+	rc = gpio_request(flash_led->gpio_pin_num, GPIO_LABEL);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: Failed to request gpio %d,rc = %d\n",
+		 __func__, flash_led->gpio_pin_num, rc);
+		goto error;
+	}
+	rc = gpio_direction_output(flash_led->gpio_pin_num, 1); /* Make sure the direction is out */
+	if (rc)
+		dev_info(&pdev->dev, "%s: Setting GPIO %d direction to out succeeded, "
+			"rc=%d.\n", __func__, flash_led->gpio_pin_num, rc);
+	else
+		dev_info(&pdev->dev, "%s: Setting GPIO %d direction to out succeeded, "
+			"rc=%d.\n", __func__, flash_led->gpio_pin_num, rc);
+
+	/* If GPIO value is 0 set to 1 so light is off initially */
+	rc = gpio_get_value_cansleep(flash_led->gpio_pin_num);
+	dev_info(&pdev->dev, "%s: GPIO (%d) initial value=%d, "
+		"changing value to %d\n",
+		__func__, flash_led->gpio_pin_num, rc, 1);
+	if (!rc)
+		gpio_set_value_cansleep(flash_led->gpio_pin_num, 1);
+	flash_led->gpio_value = gpio_get_value_cansleep(flash_led->gpio_pin_num);
+	dev_info(&pdev->dev, "%s: GPIO value=%d\n", __func__, flash_led->gpio_value);
+
+	flash_led->cdev.name = "DS2_Green_LED";
+	dev_info(&pdev->dev, "%s: cdev name=%s\n", __func__, flash_led->cdev.name);
+
+	platform_set_drvdata(pdev, flash_led);
+	flash_led->cdev.max_brightness = LED_FULL;
+	flash_led->cdev.brightness_set = led_gpio_brightness_set;
+	flash_led->cdev.brightness_get = led_gpio_brightness_get;
+
+	rc = led_classdev_register(&pdev->dev, &flash_led->cdev);
+	if (rc) {
+		dev_err(&pdev->dev, "%s: Failed to register led dev. rc = %d\n",
+			__func__, rc);
+		goto error;
+	}
+	dev_info(&pdev->dev, "%s:probe successfully!\n", __func__);
+	return 0;
+
+error:
+	devm_kfree(&pdev->dev, flash_led);
+	return rc;
+}
+
+int led_gpio_flash_remove(struct platform_device *pdev)
+{
+	struct led_gpio_flash_data *flash_led =
+	    (struct led_gpio_flash_data *)platform_get_drvdata(pdev);
+	gpio_free(flash_led->gpio_pin_num);
+	gpio_free(flash_led->gpio_pin_mux_num);
+	led_classdev_unregister(&flash_led->cdev);
+	devm_kfree(&pdev->dev, flash_led);
+	pr_debug("%s: Unregistering Intel LED GPIO driver", __func__);
+	return 0;
+}
+
+static struct platform_driver led_gpio_flash_driver = {
+	.probe = led_gpio_flash_probe,
+	.remove = led_gpio_flash_remove,
+	.driver = {
+		   .name = LED_GPIO_FLASH_DRIVER_NAME,
+		   .owner = THIS_MODULE,
+		   }
+};
+
+static int __init led_gpio_flash_init(void)
+{
+	pr_debug("%s: Registering Intel LED GPIO driver\n", __func__);
+	return platform_driver_register(&led_gpio_flash_driver);
+}
+
+static void __exit led_gpio_flash_exit(void)
+{
+	pr_debug("%s: Unregistering Intel LED GPIO driver\n", __func__);
+	return platform_driver_unregister(&led_gpio_flash_driver);
+}
+
+late_initcall(led_gpio_flash_init);
+module_exit(led_gpio_flash_exit);
+
+MODULE_DESCRIPTION("Intel GPIO LEDs driver");
+MODULE_LICENSE("GPL v2");
+