leds: add LED driver for Big Network series LEDs

This patch add a LED class driver for LEDs found on the LaCie 2Big and
5Big Network v2 boards. The LEDs are wired to a CPLD and are controlled
through a GPIO extension bus.
Signed-off-by: NSimon Guinot <sguinot@lacie.com>
Signed-off-by: NNicolas Pitre <nico@fluxnic.net>

arch/arm/mach-kirkwood/include/mach/leds-netxbig.h

+/*
+ * arch/arm/mach-kirkwood/include/mach/leds-netxbig.h
+ *
+ * Platform data structure for netxbig LED driver
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __MACH_LEDS_NETXBIG_H
+#define __MACH_LEDS_NETXBIG_H
+
+struct netxbig_gpio_ext {
+	unsigned	*addr;
+	int		num_addr;
+	unsigned	*data;
+	int		num_data;
+	unsigned	enable;
+};
+
+enum netxbig_led_mode {
+	NETXBIG_LED_OFF,
+	NETXBIG_LED_ON,
+	NETXBIG_LED_SATA,
+	NETXBIG_LED_TIMER1,
+	NETXBIG_LED_TIMER2,
+	NETXBIG_LED_MODE_NUM,
+};
+
+#define NETXBIG_LED_INVALID_MODE NETXBIG_LED_MODE_NUM
+
+struct netxbig_led_timer {
+	unsigned long		delay_on;
+	unsigned long		delay_off;
+	enum netxbig_led_mode	mode;
+};
+
+struct netxbig_led {
+	const char	*name;
+	const char	*default_trigger;
+	int		mode_addr;
+	int		*mode_val;
+	int		bright_addr;
+};
+
+struct netxbig_led_platform_data {
+	struct netxbig_gpio_ext	*gpio_ext;
+	struct netxbig_led_timer *timer;
+	int			num_timer;
+	struct netxbig_led	*leds;
+	int			num_leds;
+};
+
+#endif /* __MACH_LEDS_NETXBIG_H */

drivers/leds/Kconfig

@@ -311,6 +311,15 @@ config LEDS_NS2
 	  Network Space v2 board (and parents). This include Internet Space v2,
 	  Network Space (Max) v2 and d2 Network v2 boards.
 
+config LEDS_NETXBIG
+	tristate "LED support for Big Network series LEDs"
+	depends on MACH_NET2BIG_V2 || MACH_NET5BIG_V2
+	default y
+	help
+	  This option enable support for LEDs found on the LaCie 2Big
+	  and 5Big Network v2 boards. The LEDs are wired to a CPLD and are
+	  controlled through a GPIO extension bus.
+
 config LEDS_TRIGGERS
 	bool "LED Trigger support"
 	help

drivers/leds/Makefile

@@ -38,6 +38,7 @@ obj-$(CONFIG_LEDS_ADP5520)		+= leds-adp5520.o
 obj-$(CONFIG_LEDS_DELL_NETBOOKS)	+= dell-led.o
 obj-$(CONFIG_LEDS_MC13783)		+= leds-mc13783.o
 obj-$(CONFIG_LEDS_NS2)			+= leds-ns2.o
+obj-$(CONFIG_LEDS_NETXBIG)		+= leds-netxbig.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

drivers/leds/leds-netxbig.c

+/*
+ * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
+ *
+ * Copyright (C) 2010 LaCie
+ *
+ * Author: Simon Guinot <sguinot@lacie.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/leds.h>
+#include <mach/leds-netxbig.h>
+
+/*
+ * GPIO extension bus.
+ */
+
+static DEFINE_SPINLOCK(gpio_ext_lock);
+
+static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
+{
+	int pin;
+
+	for (pin = 0; pin < gpio_ext->num_addr; pin++)
+		gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
+}
+
+static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
+{
+	int pin;
+
+	for (pin = 0; pin < gpio_ext->num_data; pin++)
+		gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
+}
+
+static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
+{
+	/* Enable select is done on the raising edge. */
+	gpio_set_value(gpio_ext->enable, 0);
+	gpio_set_value(gpio_ext->enable, 1);
+}
+
+static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
+			       int addr, int value)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&gpio_ext_lock, flags);
+	gpio_ext_set_addr(gpio_ext, addr);
+	gpio_ext_set_data(gpio_ext, value);
+	gpio_ext_enable_select(gpio_ext);
+	spin_unlock_irqrestore(&gpio_ext_lock, flags);
+}
+
+static int __devinit gpio_ext_init(struct netxbig_gpio_ext *gpio_ext)
+{
+	int err;
+	int i;
+
+	if (unlikely(!gpio_ext))
+		return -EINVAL;
+
+	/* Configure address GPIOs. */
+	for (i = 0; i < gpio_ext->num_addr; i++) {
+		err = gpio_request(gpio_ext->addr[i], "GPIO extension addr");
+		if (err)
+			goto err_free_addr;
+		err = gpio_direction_output(gpio_ext->addr[i], 0);
+		if (err) {
+			gpio_free(gpio_ext->addr[i]);
+			goto err_free_addr;
+		}
+	}
+	/* Configure data GPIOs. */
+	for (i = 0; i < gpio_ext->num_data; i++) {
+		err = gpio_request(gpio_ext->data[i], "GPIO extension data");
+		if (err)
+			goto err_free_data;
+		err = gpio_direction_output(gpio_ext->data[i], 0);
+		if (err) {
+			gpio_free(gpio_ext->data[i]);
+			goto err_free_data;
+		}
+	}
+	/* Configure "enable select" GPIO. */
+	err = gpio_request(gpio_ext->enable, "GPIO extension enable");
+	if (err)
+		goto err_free_data;
+	err = gpio_direction_output(gpio_ext->enable, 0);
+	if (err) {
+		gpio_free(gpio_ext->enable);
+		goto err_free_data;
+	}
+
+	return 0;
+
+err_free_data:
+	for (i = i - 1; i >= 0; i--)
+		gpio_free(gpio_ext->data[i]);
+	i = gpio_ext->num_addr;
+err_free_addr:
+	for (i = i - 1; i >= 0; i--)
+		gpio_free(gpio_ext->addr[i]);
+
+	return err;
+}
+
+static void __devexit gpio_ext_free(struct netxbig_gpio_ext *gpio_ext)
+{
+	int i;
+
+	gpio_free(gpio_ext->enable);
+	for (i = gpio_ext->num_addr - 1; i >= 0; i--)
+		gpio_free(gpio_ext->addr[i]);
+	for (i = gpio_ext->num_data - 1; i >= 0; i--)
+		gpio_free(gpio_ext->data[i]);
+}
+
+/*
+ * Class LED driver.
+ */
+
+struct netxbig_led_data {
+	struct netxbig_gpio_ext	*gpio_ext;
+	struct led_classdev	cdev;
+	int			mode_addr;
+	int			*mode_val;
+	int			bright_addr;
+	int			bright_max;
+	struct			netxbig_led_timer *timer;
+	int			num_timer;
+	enum netxbig_led_mode	mode;
+	int			sata;
+	spinlock_t		lock;
+};
+
+static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
+				      unsigned long delay_on,
+				      unsigned long delay_off,
+				      struct netxbig_led_timer *timer,
+				      int num_timer)
+{
+	int i;
+
+	for (i = 0; i < num_timer; i++) {
+		if (timer[i].delay_on == delay_on &&
+		    timer[i].delay_off == delay_off) {
+			*mode = timer[i].mode;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static int netxbig_led_blink_set(struct led_classdev *led_cdev,
+				 unsigned long *delay_on,
+				 unsigned long *delay_off)
+{
+	struct netxbig_led_data *led_dat =
+		container_of(led_cdev, struct netxbig_led_data, cdev);
+	enum netxbig_led_mode mode;
+	int mode_val;
+	int ret;
+
+	/* Look for a LED mode with the requested timer frequency. */
+	ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
+					 led_dat->timer, led_dat->num_timer);
+	if (ret < 0)
+		return ret;
+
+	mode_val = led_dat->mode_val[mode];
+	if (mode_val == NETXBIG_LED_INVALID_MODE)
+		return -EINVAL;
+
+	spin_lock_irq(&led_dat->lock);
+
+	gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
+	led_dat->mode = mode;
+
+	spin_unlock_irq(&led_dat->lock);
+
+	return 0;
+}
+
+static void netxbig_led_set(struct led_classdev *led_cdev,
+			    enum led_brightness value)
+{
+	struct netxbig_led_data *led_dat =
+		container_of(led_cdev, struct netxbig_led_data, cdev);
+	enum netxbig_led_mode mode;
+	int mode_val, bright_val;
+	int set_brightness = 1;
+	unsigned long flags;
+
+	spin_lock_irqsave(&led_dat->lock, flags);
+
+	if (value == LED_OFF) {
+		mode = NETXBIG_LED_OFF;
+		set_brightness = 0;
+	} else {
+		if (led_dat->sata)
+			mode = NETXBIG_LED_SATA;
+		else if (led_dat->mode == NETXBIG_LED_OFF)
+			mode = NETXBIG_LED_ON;
+		else /* Keep 'timer' mode. */
+			mode = led_dat->mode;
+	}
+	mode_val = led_dat->mode_val[mode];
+
+	gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
+	led_dat->mode = mode;
+	/*
+	 * Note that the brightness register is shared between all the
+	 * SATA LEDs. So, change the brightness setting for a single
+	 * SATA LED will affect all the others.
+	 */
+	if (set_brightness) {
+		bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
+					  LED_FULL);
+		gpio_ext_set_value(led_dat->gpio_ext,
+				   led_dat->bright_addr, bright_val);
+	}
+
+	spin_unlock_irqrestore(&led_dat->lock, flags);
+}
+
+static ssize_t netxbig_led_sata_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buff, size_t count)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct netxbig_led_data *led_dat =
+		container_of(led_cdev, struct netxbig_led_data, cdev);
+	unsigned long enable;
+	enum netxbig_led_mode mode;
+	int mode_val;
+	int ret;
+
+	ret = strict_strtoul(buff, 10, &enable);
+	if (ret < 0)
+		return ret;
+
+	enable = !!enable;
+
+	spin_lock_irq(&led_dat->lock);
+
+	if (led_dat->sata == enable) {
+		ret = count;
+		goto exit_unlock;
+	}
+
+	if (led_dat->mode != NETXBIG_LED_ON &&
+	    led_dat->mode != NETXBIG_LED_SATA)
+		mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
+	else if (enable)
+		mode = NETXBIG_LED_SATA;
+	else
+		mode = NETXBIG_LED_ON;
+
+	mode_val = led_dat->mode_val[mode];
+	if (mode_val == NETXBIG_LED_INVALID_MODE) {
+		ret = -EINVAL;
+		goto exit_unlock;
+	}
+
+	gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
+	led_dat->mode = mode;
+	led_dat->sata = enable;
+
+	ret = count;
+
+exit_unlock:
+	spin_unlock_irq(&led_dat->lock);
+
+	return ret;
+}
+
+static ssize_t netxbig_led_sata_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct netxbig_led_data *led_dat =
+		container_of(led_cdev, struct netxbig_led_data, cdev);
+
+	return sprintf(buf, "%d\n", led_dat->sata);
+}
+
+static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
+
+static void __devexit delete_netxbig_led(struct netxbig_led_data *led_dat)
+{
+	if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
+		device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
+	led_classdev_unregister(&led_dat->cdev);
+}
+
+static int __devinit
+create_netxbig_led(struct platform_device *pdev,
+		   struct netxbig_led_data *led_dat,
+		   const struct netxbig_led *template)
+{
+	struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
+	int ret;
+
+	spin_lock_init(&led_dat->lock);
+	led_dat->gpio_ext = pdata->gpio_ext;
+	led_dat->cdev.name = template->name;
+	led_dat->cdev.default_trigger = template->default_trigger;
+	led_dat->cdev.blink_set = netxbig_led_blink_set;
+	led_dat->cdev.brightness_set = netxbig_led_set;
+	/*
+	 * Because the GPIO extension bus don't allow to read registers
+	 * value, there is no way to probe the LED initial state.
+	 * So, the initial sysfs LED value for the "brightness" and "sata"
+	 * attributes are inconsistent.
+	 *
+	 * Note that the initial LED state can't be reconfigured.
+	 * The reason is that the LED behaviour must stay uniform during
+	 * the whole boot process (bootloader+linux).
+	 */
+	led_dat->sata = 0;
+	led_dat->cdev.brightness = LED_OFF;
+	led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
+	led_dat->mode_addr = template->mode_addr;
+	led_dat->mode_val = template->mode_val;
+	led_dat->bright_addr = template->bright_addr;
+	led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
+	led_dat->timer = pdata->timer;
+	led_dat->num_timer = pdata->num_timer;
+
+	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * If available, expose the SATA activity blink capability through
+	 * a "sata" sysfs attribute.
+	 */
+	if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE) {
+		ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
+		if (ret)
+			led_classdev_unregister(&led_dat->cdev);
+	}
+
+	return ret;
+}
+
+static int __devinit netxbig_led_probe(struct platform_device *pdev)
+{
+	struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
+	struct netxbig_led_data *leds_data;
+	int i;
+	int ret;
+
+	if (!pdata)
+		return -EINVAL;
+
+	leds_data = kzalloc(sizeof(struct netxbig_led_data) * pdata->num_leds,
+			    GFP_KERNEL);
+	if (!leds_data)
+		return -ENOMEM;
+
+	ret = gpio_ext_init(pdata->gpio_ext);
+	if (ret < 0)
+		goto err_free_data;
+
+	for (i = 0; i < pdata->num_leds; i++) {
+		ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
+		if (ret < 0)
+			goto err_free_leds;
+	}
+
+	platform_set_drvdata(pdev, leds_data);
+
+	return 0;
+
+err_free_leds:
+	for (i = i - 1; i >= 0; i--)
+		delete_netxbig_led(&leds_data[i]);
+
+	gpio_ext_free(pdata->gpio_ext);
+err_free_data:
+	kfree(leds_data);
+
+	return ret;
+}
+
+static int __devexit netxbig_led_remove(struct platform_device *pdev)
+{
+	struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
+	struct netxbig_led_data *leds_data;
+	int i;
+
+	leds_data = platform_get_drvdata(pdev);
+
+	for (i = 0; i < pdata->num_leds; i++)
+		delete_netxbig_led(&leds_data[i]);
+
+	gpio_ext_free(pdata->gpio_ext);
+	kfree(leds_data);
+
+	return 0;
+}
+
+static struct platform_driver netxbig_led_driver = {
+	.probe		= netxbig_led_probe,
+	.remove		= __devexit_p(netxbig_led_remove),
+	.driver		= {
+		.name	= "leds-netxbig",
+		.owner	= THIS_MODULE,
+	},
+};
+MODULE_ALIAS("platform:leds-netxbig");
+
+static int __init netxbig_led_init(void)
+{
+	return platform_driver_register(&netxbig_led_driver);
+}
+
+static void __exit netxbig_led_exit(void)
+{
+	platform_driver_unregister(&netxbig_led_driver);
+}
+
+module_init(netxbig_led_init);
+module_exit(netxbig_led_exit);
+
+MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
+MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
+MODULE_LICENSE("GPL");