add led driver for Bachmann's ot200

From: Sebastian Andrzej Siewior <[email protected] <mailto:[email protected]>>
Date: Mon, 9 Jan 2012 14:44:46 +0100
Subject: [PATCH v3] add led driver for Bachmann's ot200

This patch adds support for leds on Bachmann's ot200 visualisation device. The device has three leds on the back panel (led_err, led_init and led_run) and can handle up to seven leds on the front panel.

The driver was written by Linutronix on behalf of
Bachmann electronic GmbH.

Changes in v3:
- incorporated feedback from Lars-Peter Clausen

Changes in v2:
- incorporated feedback from Andrew Morton and Lars-Peter Clausen

---
 drivers/leds/Kconfig      |    7 ++
 drivers/leds/Makefile     |    1 +
 drivers/leds/leds-ot200.c |  171
+++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 179 insertions(+), 0 deletions(-)
 create mode 100644 drivers/leds/leds-ot200.c

index ff203a4..71cb89b 100644
@@ -387,6 +387,13 @@ config LEDS_RENESAS_TPU
 	  pin function. The latter to support brightness control.
 	  Brightness control is supported but hardware blinking is not.
 
+config LEDS_OT200
+	tristate "LED support for the Bachmann OT200"
+	depends on LEDS_CLASS
+	help
+	  This option enables support for the LEDs on the Bachmann OT200.
+	  Say Y to enable LEDs on the Bachmann OT200.
+
 config LEDS_TRIGGERS
 	bool "LED Trigger support"
 	depends on LEDS_CLASS

index e4f6bf5..0814d42 100644
@@ -43,6 +43,7 @@ obj-$(CONFIG_LEDS_NS2)			+= leds-ns2.o
 obj-$(CONFIG_LEDS_NETXBIG)		+= leds-netxbig.o
 obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
 obj-$(CONFIG_LEDS_RENESAS_TPU)		+= leds-renesas-tpu.o
+obj-$(CONFIG_LEDS_OT200)		+= leds-ot200.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

new file mode 100644
index 0000000..c464682
@@ -0,0 +1,171 @@
+/*
+ * Bachmann ot200 leds driver.
+ *
+ * Author: Sebastian Andrzej Siewior <[email protected]>
+ *         Christian Gmeiner <[email protected]>
+ *
+ * License: GPL as published by the FSF.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/leds.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+
+struct ot200_led {
+	struct led_classdev cdev;
+	const char *name;
+	unsigned long port;
+	u8 mask;
+};
+
+/*
+ * The device has three leds on the back panel (led_err, led_init and

led_run)
+ * and can handle up to seven leds on the front panel.
+ */
+
+static struct ot200_led leds[] = {
+ {
+ .name = "led_run",
+ .port = 0x5a,
+ .mask = BIT(0),
+ },
+ {
+ .name = "led_init",
+ .port = 0x5a,
+ .mask = BIT(1),
+ },
+ {
+ .name = "led_err",
+ .port = 0x5a,
+ .mask = BIT(2),
+ },
+ {
+ .name = "led_1",
+ .port = 0x49,
+ .mask = BIT(7),
+ },
+ {
+ .name = "led_2",
+ .port = 0x49,
+ .mask = BIT(6),
+ },
+ {
+ .name = "led_3",
+ .port = 0x49,
+ .mask = BIT(5),
+ },
+ {
+ .name = "led_4",
+ .port = 0x49,
+ .mask = BIT(4),
+ },
+ {
+ .name = "led_5",
+ .port = 0x49,
+ .mask = BIT(3),
+ },
+ {
+ .name = "led_6",
+ .port = 0x49,
+ .mask = BIT(2),
+ },
+ {
+ .name = "led_7",
+ .port = 0x49,
+ .mask = BIT(1),
+ }
+};
+
+static DEFINE_SPINLOCK(value_lock);
+
+/*
+ * we need to store the current led states, as it is not
+ * possible to read the current led state via inb().
+ */
+static u8 leds_back;
+static u8 leds_front;
+
+static void ot200_led_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
+ u8 *val;
+ unsigned long flags;
+
+ spin_lock_irqsave(&value_lock, flags);
+
+ if (led->port == 0x49)
+ val = &leds_front;
+ else if (led->port == 0x5a)
+ val = &leds_back;
+ else
+ BUG();
+
+ if (value == LED_OFF)
+ *val &= ~led->mask;
+ else
+ *val |= led->mask;
+
+ outb(*val, led->port);
+ spin_unlock_irqrestore(&value_lock, flags);
+}
+
+static int __devinit ot200_led_probe(struct platform_device *pdev) +{
+ int i;
+ int ret;
+
+ for (i = 0; i < ARRAY_SIZE(leds); i++) {
+
+ leds[i].cdev.name = leds[i].name;
+ leds[i].cdev.brightness_set = ot200_led_brightness_set;
+
+ ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
+ if (ret < 0)
+ goto err;
+ }
+
+ leds_front = 0; /* turn off all front leds */
+ leds_back = BIT(1); /* turn on init led */
+ outb(leds_front, 0x49);
+ outb(leds_back, 0x5a);
+
+ return 0;
+
+err:
+ for (i = i - 1; i >= 0; i--)
+ led_classdev_unregister(&leds[i].cdev);
+
+ return ret;
+}
+
+static int __devexit ot200_led_remove(struct platform_device *pdev) +{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(leds); i++)
+ led_classdev_unregister(&leds[i].cdev);
+
+ return 0;
+}
+
+static struct platform_driver ot200_led_driver = {
+ .probe = ot200_led_probe,
+ .remove = __devexit_p(ot200_led_remove),
+ .driver = {
+ .name = "leds-ot200",
+ .owner = THIS_MODULE,
+ },
+};
+
+module_platform_driver(ot200_led_driver);
+
+MODULE_AUTHOR("Sebastian A. Siewior <[email protected]>"); +MODULE_DESCRIPTION("ot200 LED driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:leds-ot200");

1.7.5.4