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-rw-r--r--drivers/video/backlight/Kconfig7
-rw-r--r--drivers/video/backlight/Makefile1
-rw-r--r--drivers/video/backlight/pwm_bl.c185
-rw-r--r--drivers/video/pxafb.c44
4 files changed, 237 insertions, 0 deletions
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index dcd8073c236..30bf7f2f163 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -112,3 +112,10 @@ config BACKLIGHT_CARILLO_RANCH
help
If you have a Intel LE80578 (Carillo Ranch) say Y to enable the
backlight driver.
+
+config BACKLIGHT_PWM
+ tristate "Generic PWM based Backlight Driver"
+ depends on BACKLIGHT_CLASS_DEVICE && HAVE_PWM
+ help
+ If you have a LCD backlight adjustable by PWM, say Y to enable
+ this driver.
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 33f6c7cecc7..b51a7cd1250 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o
obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
+obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
new file mode 100644
index 00000000000..6338d0e2fe0
--- /dev/null
+++ b/drivers/video/backlight/pwm_bl.c
@@ -0,0 +1,185 @@
+/*
+ * linux/drivers/video/backlight/pwm_bl.c
+ *
+ * simple PWM based backlight control, board code has to setup
+ * 1) pin configuration so PWM waveforms can output
+ * 2) platform_data casts to the PWM id (0/1/2/3 on PXA)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/pwm.h>
+#include <linux/pwm_backlight.h>
+
+struct pwm_bl_data {
+ struct pwm_device *pwm;
+ unsigned int period;
+ int (*notify)(int brightness);
+};
+
+static int pwm_backlight_update_status(struct backlight_device *bl)
+{
+ struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+ int brightness = bl->props.brightness;
+ int max = bl->props.max_brightness;
+
+ if (bl->props.power != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (pb->notify)
+ brightness = pb->notify(brightness);
+
+ if (brightness == 0) {
+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+ } else {
+ pwm_config(pb->pwm, brightness * pb->period / max, pb->period);
+ pwm_enable(pb->pwm);
+ }
+ return 0;
+}
+
+static int pwm_backlight_get_brightness(struct backlight_device *bl)
+{
+ return bl->props.brightness;
+}
+
+static struct backlight_ops pwm_backlight_ops = {
+ .update_status = pwm_backlight_update_status,
+ .get_brightness = pwm_backlight_get_brightness,
+};
+
+static int pwm_backlight_probe(struct platform_device *pdev)
+{
+ struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
+ struct backlight_device *bl;
+ struct pwm_bl_data *pb;
+ int ret;
+
+ if (!data)
+ return -EINVAL;
+
+ if (data->init) {
+ ret = data->init(&pdev->dev);
+ if (ret < 0)
+ return ret;
+ }
+
+ pb = kzalloc(sizeof(*pb), GFP_KERNEL);
+ if (!pb) {
+ ret = -ENOMEM;
+ goto err_alloc;
+ }
+
+ pb->period = data->pwm_period_ns;
+ pb->notify = data->notify;
+
+ pb->pwm = pwm_request(data->pwm_id, "backlight");
+ if (IS_ERR(pb->pwm)) {
+ dev_err(&pdev->dev, "unable to request PWM for backlight\n");
+ ret = PTR_ERR(pb->pwm);
+ goto err_pwm;
+ }
+
+ bl = backlight_device_register(pdev->name, &pdev->dev,
+ pb, &pwm_backlight_ops);
+ if (IS_ERR(bl)) {
+ dev_err(&pdev->dev, "failed to register backlight\n");
+ ret = PTR_ERR(bl);
+ goto err_bl;
+ }
+
+ bl->props.max_brightness = data->max_brightness;
+ bl->props.brightness = data->dft_brightness;
+ backlight_update_status(bl);
+
+ platform_set_drvdata(pdev, bl);
+ return 0;
+
+err_bl:
+ pwm_free(pb->pwm);
+err_pwm:
+ kfree(pb);
+err_alloc:
+ if (data->exit)
+ data->exit(&pdev->dev);
+ return ret;
+}
+
+static int pwm_backlight_remove(struct platform_device *pdev)
+{
+ struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
+ struct backlight_device *bl = platform_get_drvdata(pdev);
+ struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+ backlight_device_unregister(bl);
+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+ pwm_free(pb->pwm);
+ kfree(pb);
+ if (data->exit)
+ data->exit(&pdev->dev);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int pwm_backlight_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ struct backlight_device *bl = platform_get_drvdata(pdev);
+ struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+ return 0;
+}
+
+static int pwm_backlight_resume(struct platform_device *pdev)
+{
+ struct backlight_device *bl = platform_get_drvdata(pdev);
+
+ backlight_update_status(bl);
+ return 0;
+}
+#else
+#define pwm_backlight_suspend NULL
+#define pwm_backlight_resume NULL
+#endif
+
+static struct platform_driver pwm_backlight_driver = {
+ .driver = {
+ .name = "pwm-backlight",
+ .owner = THIS_MODULE,
+ },
+ .probe = pwm_backlight_probe,
+ .remove = pwm_backlight_remove,
+ .suspend = pwm_backlight_suspend,
+ .resume = pwm_backlight_resume,
+};
+
+static int __init pwm_backlight_init(void)
+{
+ return platform_driver_register(&pwm_backlight_driver);
+}
+module_init(pwm_backlight_init);
+
+static void __exit pwm_backlight_exit(void)
+{
+ platform_driver_unregister(&pwm_backlight_driver);
+}
+module_exit(pwm_backlight_exit);
+
+MODULE_DESCRIPTION("PWM based Backlight Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index 3ee314beacc..3682bbd7e50 100644
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c
@@ -1777,11 +1777,49 @@ failed:
return ret;
}
+static int __devexit pxafb_remove(struct platform_device *dev)
+{
+ struct pxafb_info *fbi = platform_get_drvdata(dev);
+ struct resource *r;
+ int irq;
+ struct fb_info *info;
+
+ if (!fbi)
+ return 0;
+
+ info = &fbi->fb;
+
+ unregister_framebuffer(info);
+
+ pxafb_disable_controller(fbi);
+
+ if (fbi->fb.cmap.len)
+ fb_dealloc_cmap(&fbi->fb.cmap);
+
+ irq = platform_get_irq(dev, 0);
+ free_irq(irq, fbi);
+
+ dma_free_writecombine(&dev->dev, fbi->map_size,
+ fbi->map_cpu, fbi->map_dma);
+
+ iounmap(fbi->mmio_base);
+
+ r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ release_mem_region(r->start, r->end - r->start + 1);
+
+ clk_put(fbi->clk);
+ kfree(fbi);
+
+ return 0;
+}
+
static struct platform_driver pxafb_driver = {
.probe = pxafb_probe,
+ .remove = pxafb_remove,
.suspend = pxafb_suspend,
.resume = pxafb_resume,
.driver = {
+ .owner = THIS_MODULE,
.name = "pxa2xx-fb",
},
};
@@ -1794,7 +1832,13 @@ static int __devinit pxafb_init(void)
return platform_driver_register(&pxafb_driver);
}
+static void __exit pxafb_exit(void)
+{
+ platform_driver_unregister(&pxafb_driver);
+}
+
module_init(pxafb_init);
+module_exit(pxafb_exit);
MODULE_DESCRIPTION("loadable framebuffer driver for PXA");
MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 18:33:21 +0000