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: Simon Guinot <sguinot@lacie.com>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>

1 files changed, 449 insertions, 0 deletions

diff --git a/drivers/leds/leds-netxbig.c b/drivers/leds/leds-netxbig.c
new file mode 100644
index 000000000000..f2e51c134399
--- /dev/null
+++ b/drivers/leds/leds-netxbig.c
@@ -0,0 +1,449 @@
+/*
+ * 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");