[PATCH] LED: add LED device support for ixp4xx devices
authorJohn Bowler <jbowler@acm.org>
Fri, 31 Mar 2006 10:31:11 +0000 (02:31 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Fri, 31 Mar 2006 20:18:57 +0000 (12:18 -0800)
NEW_LEDS support for ixp4xx boards where LEDs are connected to the GPIO lines.

This includes a new generic ixp4xx driver (leds-ixp4xx-gpio.c name
"IXP4XX-GPIO-LED")

Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-ixp4xx-gpio.c [new file with mode: 0644]

index 6099e32985aaae207c512c40ef2959e617f0e577..d9e2f9853b9d88d4ff382cabfefafa9d2a358f5f 100644 (file)
@@ -43,6 +43,15 @@ config LEDS_SPITZ
          This option enables support for the LEDs on Sharp Zaurus
          SL-Cxx00 series (C1000, C3000, C3100).
 
+config LEDS_IXP4XX
+       tristate "LED Support for GPIO connected LEDs on IXP4XX processors"
+       depends LEDS_CLASS && ARCH_IXP4XX
+       help
+         This option enables support for the LEDs connected to GPIO
+         outputs of the Intel IXP4XX processors.  To be useful the
+         particular board must have LEDs and they must be connected
+         to the GPIO lines.  If unsure, say Y.
+
 config LEDS_TRIGGER_TIMER
        tristate "LED Timer Trigger"
        depends LEDS_TRIGGERS
index d60e12b8af24d85e00f9a006f3b4561044236e4e..b1187c0b36ce93ced0a79e8d4812a027a8465ab6 100644 (file)
@@ -8,6 +8,7 @@ obj-$(CONFIG_LEDS_TRIGGERS)             += led-triggers.o
 obj-$(CONFIG_LEDS_CORGI)               += leds-corgi.o
 obj-$(CONFIG_LEDS_LOCOMO)              += leds-locomo.o
 obj-$(CONFIG_LEDS_SPITZ)               += leds-spitz.o
+obj-$(CONFIG_LEDS_IXP4XX)              += leds-ixp4xx-gpio.o
 
 # LED Triggers
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)       += ledtrig-timer.o
diff --git a/drivers/leds/leds-ixp4xx-gpio.c b/drivers/leds/leds-ixp4xx-gpio.c
new file mode 100644 (file)
index 0000000..30ced15
--- /dev/null
@@ -0,0 +1,215 @@
+/*
+ * IXP4XX GPIO driver LED driver
+ *
+ * Author: John Bowler <jbowler@acm.org>
+ *
+ * Copyright (c) 2006 John Bowler
+ *
+ * Permission is hereby granted, free of charge, to any
+ * person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the
+ * Software without restriction, including without
+ * limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the
+ * following conditions:
+ *
+ * The above copyright notice and this permission notice
+ * shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ * ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+ * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+ * SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/leds.h>
+#include <asm/arch/hardware.h>
+
+extern spinlock_t gpio_lock;
+
+/* Up to 16 gpio lines are possible. */
+#define GPIO_MAX 16
+static struct ixp4xxgpioled_device {
+       struct led_classdev ancestor;
+       int               flags;
+} ixp4xxgpioled_devices[GPIO_MAX];
+
+void ixp4xxgpioled_brightness_set(struct led_classdev *pled,
+                               enum led_brightness value)
+{
+       const struct ixp4xxgpioled_device *const ixp4xx_dev =
+               container_of(pled, struct ixp4xxgpioled_device, ancestor);
+       const u32 gpio_pin = ixp4xx_dev - ixp4xxgpioled_devices;
+
+       if (gpio_pin < GPIO_MAX && ixp4xx_dev->ancestor.name != 0) {
+               /* Set or clear the 'gpio_pin' bit according to the style
+                * and the required setting (value > 0 == on)
+                */
+               const int gpio_value =
+                       (value > 0) == (ixp4xx_dev->flags != IXP4XX_GPIO_LOW) ?
+                               IXP4XX_GPIO_HIGH : IXP4XX_GPIO_LOW;
+
+               {
+                       unsigned long flags;
+                       spin_lock_irqsave(&gpio_lock, flags);
+                       gpio_line_set(gpio_pin, gpio_value);
+                       spin_unlock_irqrestore(&gpio_lock, flags);
+               }
+       }
+}
+
+/* LEDs are described in resources, the following iterates over the valid
+ * LED resources.
+ */
+#define for_all_leds(i, pdev) \
+       for (i=0; i<pdev->num_resources; ++i) \
+               if (pdev->resource[i].start < GPIO_MAX && \
+                       pdev->resource[i].name != 0)
+
+/* The following applies 'operation' to each LED from the given platform,
+ * the function always returns 0 to allow tail call elimination.
+ */
+static int apply_to_all_leds(struct platform_device *pdev,
+       void (*operation)(struct led_classdev *pled))
+{
+       int i;
+
+       for_all_leds(i, pdev)
+               operation(&ixp4xxgpioled_devices[pdev->resource[i].start].ancestor);
+       return 0;
+}
+
+#ifdef CONFIG_PM
+static int ixp4xxgpioled_suspend(struct platform_device *pdev,
+                               pm_message_t state)
+{
+       return apply_to_all_leds(pdev, led_classdev_suspend);
+}
+
+static int ixp4xxgpioled_resume(struct platform_device *pdev)
+{
+       return apply_to_all_leds(pdev, led_classdev_resume);
+}
+#endif
+
+static void ixp4xxgpioled_remove_one_led(struct led_classdev *pled)
+{
+       led_classdev_unregister(pled);
+       pled->name = 0;
+}
+
+static int ixp4xxgpioled_remove(struct platform_device *pdev)
+{
+       return apply_to_all_leds(pdev, ixp4xxgpioled_remove_one_led);
+}
+
+static int ixp4xxgpioled_probe(struct platform_device *pdev)
+{
+       /* The board level has to tell the driver where the
+        * LEDs are connected - there is no way to find out
+        * electrically.  It must also say whether the GPIO
+        * lines are active high or active low.
+        *
+        * To do this read the num_resources (the number of
+        * LEDs) and the struct resource (the data for each
+        * LED).  The name comes from the resource, and it
+        * isn't copied.
+        */
+       int i;
+
+       for_all_leds(i, pdev) {
+               const u8 gpio_pin = pdev->resource[i].start;
+               int      rc;
+
+               if (ixp4xxgpioled_devices[gpio_pin].ancestor.name == 0) {
+                       unsigned long flags;
+
+                       spin_lock_irqsave(&gpio_lock, flags);
+                       gpio_line_config(gpio_pin, IXP4XX_GPIO_OUT);
+                       /* The config can, apparently, reset the state,
+                        * I suspect the gpio line may be an input and
+                        * the config may cause the line to be latched,
+                        * so the setting depends on how the LED is
+                        * connected to the line (which affects how it
+                        * floats if not driven).
+                        */
+                       gpio_line_set(gpio_pin, IXP4XX_GPIO_HIGH);
+                       spin_unlock_irqrestore(&gpio_lock, flags);
+
+                       ixp4xxgpioled_devices[gpio_pin].flags =
+                               pdev->resource[i].flags & IORESOURCE_BITS;
+
+                       ixp4xxgpioled_devices[gpio_pin].ancestor.name =
+                               pdev->resource[i].name;
+
+                       /* This is how a board manufacturer makes the LED
+                        * come on on reset - the GPIO line will be high, so
+                        * make the LED light when the line is low...
+                        */
+                       if (ixp4xxgpioled_devices[gpio_pin].flags != IXP4XX_GPIO_LOW)
+                               ixp4xxgpioled_devices[gpio_pin].ancestor.brightness = 100;
+                       else
+                               ixp4xxgpioled_devices[gpio_pin].ancestor.brightness = 0;
+
+                       ixp4xxgpioled_devices[gpio_pin].ancestor.flags = 0;
+
+                       ixp4xxgpioled_devices[gpio_pin].ancestor.brightness_set =
+                               ixp4xxgpioled_brightness_set;
+
+                       ixp4xxgpioled_devices[gpio_pin].ancestor.default_trigger = 0;
+               }
+
+               rc = led_classdev_register(&pdev->dev,
+                               &ixp4xxgpioled_devices[gpio_pin].ancestor);
+               if (rc < 0) {
+                       ixp4xxgpioled_devices[gpio_pin].ancestor.name = 0;
+                       ixp4xxgpioled_remove(pdev);
+                       return rc;
+               }
+       }
+
+       return 0;
+}
+
+static struct platform_driver ixp4xxgpioled_driver = {
+       .probe   = ixp4xxgpioled_probe,
+       .remove  = ixp4xxgpioled_remove,
+#ifdef CONFIG_PM
+       .suspend = ixp4xxgpioled_suspend,
+       .resume  = ixp4xxgpioled_resume,
+#endif
+       .driver  = {
+               .name = "IXP4XX-GPIO-LED",
+       },
+};
+
+static int __init ixp4xxgpioled_init(void)
+{
+       return platform_driver_register(&ixp4xxgpioled_driver);
+}
+
+static void __exit ixp4xxgpioled_exit(void)
+{
+       platform_driver_unregister(&ixp4xxgpioled_driver);
+}
+
+module_init(ixp4xxgpioled_init);
+module_exit(ixp4xxgpioled_exit);
+
+MODULE_AUTHOR("John Bowler <jbowler@acm.org>");
+MODULE_DESCRIPTION("IXP4XX GPIO LED driver");
+MODULE_LICENSE("Dual MIT/GPL");