[PATCH] add led driver for Bachmann's ot200

[Sebastian Andrzej Siewior]

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.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Christian Gmeiner <christian.gmeiner@xxxxxxxxx>
---
 drivers/leds/Kconfig      |    8 ++
 drivers/leds/Makefile     |    1 +
 drivers/leds/leds-ot200.c |  204 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 213 insertions(+), 0 deletions(-)
 create mode 100644 drivers/leds/leds-ot200.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ff203a4..6cf0dd6 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -387,6 +387,14 @@ 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 Bachmann OT200"
+	depends on LEDS_CLASS
+	help
+	  This option enables support for the LEDs on the Bachmann OT200. The
+	  LEDs are controlled through LPC bus.
+	  Say Y to enable LEDs on the Bachmann OT200.
+
 config LEDS_TRIGGERS
 	bool "LED Trigger support"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index e4f6bf5..0814d42 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -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
diff --git a/drivers/leds/leds-ot200.c b/drivers/leds/leds-ot200.c
new file mode 100644
index 0000000..60f118b
--- /dev/null
+++ b/drivers/leds/leds-ot200.c
@@ -0,0 +1,204 @@
+/*
+ * Bachmann ot200 leds driver.
+ *
+ * Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
+ * License: GPL as published by the FSF.
+ */
+
+#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;
+	char name[8];
+	unsigned int num;
+};
+
+static u8 old_val;
+static u8 old_val_back;
+DEFINE_SPINLOCK(value_lock);
+
+static void ot200_led_set(struct led_classdev *led_cdev,
+			enum led_brightness value)
+{
+	struct ot200_led *led =	container_of(led_cdev, struct ot200_led, cdev);
+	u8 val;
+	u8 mask;
+	unsigned long flags;
+
+	mask = 1 << led->num;
+
+	spin_lock_irqsave(&value_lock, flags);
+	val = old_val;
+
+	if (value == LED_OFF)
+		val &= ~mask;
+	else
+		val |= mask;
+
+	old_val = val;
+	spin_unlock_irqrestore(&value_lock, flags);
+	outb(val, 0x49);
+}
+
+static void ot200_led_back_set(struct led_classdev *led_cdev,
+			enum led_brightness value)
+{
+	struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
+	u8 val;
+	u8 mask;
+	unsigned long flags;
+
+	mask = 1 << led->num;
+
+	spin_lock_irqsave(&value_lock, flags);
+	val = old_val_back;
+
+	if (value == LED_OFF)
+		val &= ~mask;
+	else
+		val |= mask;
+
+	old_val_back = val;
+	spin_unlock_irqrestore(&value_lock, flags);
+	outb(val, 0x5a);
+}
+
+static int __devinit create_ot200_led(struct platform_device *pdev, int num,
+		struct ot200_led *led)
+{
+	int ret;
+
+	num += 1;
+	snprintf(led->name, sizeof(led->name), "led%d", num);
+	led->num = 7 - num;
+	led->cdev.name = led->name;
+	led->cdev.default_trigger = NULL;
+	led->cdev.blink_set = NULL;
+	led->cdev.brightness_set = ot200_led_set;
+
+	ret = led_classdev_register(&pdev->dev, &led->cdev);
+	if (ret < 0)
+		goto out;
+
+	dev_set_drvdata(led->cdev.dev, led);
+	return 0;
+
+	led_classdev_unregister(&led->cdev);
+out:
+	return ret;
+}
+
+static int __devinit create_ot200_led_back(struct platform_device *pdev,
+		int num, struct ot200_led *led)
+{
+	char *led_name;
+	int ret;
+
+	switch (num) {
+	case 0:
+		led_name = "run";
+		break;
+	case 1:
+		led_name = "init";
+		break;
+	case 2:
+		led_name = "err";
+		break;
+	default:
+		BUG();
+	};
+
+	snprintf(led->name, sizeof(led->name), "led_%s", led_name);
+	led->num = num;
+	led->cdev.name = led->name;
+	led->cdev.blink_set = NULL;
+	led->cdev.brightness_set = ot200_led_back_set;
+
+	ret = led_classdev_register(&pdev->dev, &led->cdev);
+	if (ret < 0)
+		goto out;
+
+	dev_set_drvdata(led->cdev.dev, led);
+	return 0;
+
+	led_classdev_unregister(&led->cdev);
+out:
+	return ret;
+
+}
+
+#define NUM_LEDS	7
+#define NUM_LEDS_BACK	3
+#define NUM_LEDS_TOTAL	(NUM_LEDS + NUM_LEDS_BACK)
+
+static int __devinit ot200_led_probe(struct platform_device *pdev)
+{
+	struct ot200_led *leds;
+	int i;
+	int ret;
+
+	leds = kzalloc(sizeof(struct ot200_led) * NUM_LEDS_TOTAL, GFP_KERNEL);
+	if (!leds)
+		return -ENOMEM;
+
+	for (i = 0; i < NUM_LEDS; i++) {
+		ret = create_ot200_led(pdev, i, &leds[i]);
+		if (ret < 0)
+			goto err;
+	}
+
+	for (i = NUM_LEDS; i < NUM_LEDS + NUM_LEDS_BACK; i++) {
+		ret = create_ot200_led_back(pdev, i - NUM_LEDS, &leds[i]);
+		if (ret < 0)
+			goto err;
+	}
+
+	platform_set_drvdata(pdev, leds);
+	outb(0x0, 0x49);	/* turn of all front leds */
+	outb(0x2, 0x5a);	/* turn on init led */
+	return 0;
+
+err:
+	for (i = i - 1; i >= 0; i--)
+		led_classdev_unregister(&leds[i].cdev);
+
+	kfree(leds);
+
+	return ret;
+}
+
+static int __devexit ot200_led_remove(struct platform_device *pdev)
+{
+	int i;
+	struct ot200_led *leds;
+
+	leds = platform_get_drvdata(pdev);
+
+	for (i = 0; i < NUM_LEDS_TOTAL; i++)
+		led_classdev_unregister(&leds[i].cdev);
+
+	kfree(leds);
+	platform_set_drvdata(pdev, NULL);
+
+	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 <bigeasy@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("ot200 LED driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:leds-ot200");
-- 
1.7.5.4
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