[PATCH] add led driver for Bachmann's ot200

From: Sebastian Andrzej Siewior
Date: Fri Nov 18 2011 - 04:21:48 EST


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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