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authorSrikant Patnaik2015-01-13 15:08:24 +0530
committerSrikant Patnaik2015-01-13 15:08:24 +0530
commit97327692361306d1e6259021bc425e32832fdb50 (patch)
treefe9088f3248ec61e24f404f21b9793cb644b7f01 /drivers/video/backlight/pwm_bl.c
parent2d05a8f663478a44e088d122e0d62109bbc801d0 (diff)
parenta3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff)
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dirty fix to merging
Diffstat (limited to 'drivers/video/backlight/pwm_bl.c')
-rw-r--r--drivers/video/backlight/pwm_bl.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
new file mode 100644
index 00000000..5671093c
--- /dev/null
+++ b/drivers/video/backlight/pwm_bl.c
@@ -0,0 +1,259 @@
+/*++
+ linux/drivers/video/backlight/pwm_bl.c
+
+ Copyright (c) 2013 WonderMedia Technologies, Inc.
+
+ This program is free software: you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software Foundation,
+ either version 2 of the License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ You should have received a copy of the GNU General Public License along with
+ this program. If not, see <http://www.gnu.org/licenses/>.
+
+ WonderMedia Technologies, Inc.
+ 10F, 529, Chung-Cheng Road, Hsin-Tien, Taipei 231, R.O.C.
+--*/
+
+#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>
+#include <linux/slab.h>
+
+#include <mach/hardware.h>
+
+struct pwm_bl_data {
+ struct pwm_device *pwm;
+ struct device *dev;
+ unsigned int invert;
+ unsigned int period;
+ unsigned int lth_ns;
+ unsigned int hth_ns;
+ int (*notify)(struct device *,
+ int brightness);
+ void (*notify_after)(struct device *,
+ int brightness);
+ int (*check_fb)(struct device *, struct fb_info *);
+};
+
+static inline void __pwm0_gpio_setup(void)
+{
+ /* select pwm function */
+ REG8_VAL(GPIO_CTRL_GP20_PWM0_BYTE_ADDR) &= ~0x1;
+
+ /* pwm0 output enable */
+ REG8_VAL(GPIO_OD_GP20_PWM0_BYTE_ADDR) &= ~0x01;
+
+ /* share pin */
+ REG32_VAL(PIN_SHARING_SEL_4BYTE_ADDR) &= ~0x1000;
+}
+
+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(pb->dev, brightness);
+
+ if (brightness == 0) {
+ if (pb->invert) {
+ pwm_config(pb->pwm, pb->period, pb->period);
+ } else {
+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+ }
+ } else {
+ brightness = pb->lth_ns +
+ (brightness * (pb->period - pb->lth_ns - pb->hth_ns) / max);
+ if (pb->invert)
+ brightness = pb->period - brightness;
+ pwm_config(pb->pwm, brightness, pb->period);
+ pwm_enable(pb->pwm);
+ }
+
+ if (pb->notify_after)
+ pb->notify_after(pb->dev, brightness);
+
+ return 0;
+}
+
+static int pwm_backlight_get_brightness(struct backlight_device *bl)
+{
+ return bl->props.brightness;
+}
+
+static int pwm_backlight_check_fb(struct backlight_device *bl,
+ struct fb_info *info)
+{
+ struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+ return !pb->check_fb || pb->check_fb(pb->dev, info);
+}
+
+static const struct backlight_ops pwm_backlight_ops = {
+ .update_status = pwm_backlight_update_status,
+ .get_brightness = pwm_backlight_get_brightness,
+ .check_fb = pwm_backlight_check_fb,
+};
+
+static int pwm_backlight_probe(struct platform_device *pdev)
+{
+ struct backlight_properties props;
+ struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
+ struct backlight_device *bl;
+ struct pwm_bl_data *pb;
+ int ret;
+
+ if (!data) {
+ dev_err(&pdev->dev, "failed to find platform data\n");
+ return -EINVAL;
+ }
+
+ if (data->init) {
+ ret = data->init(&pdev->dev);
+ if (ret < 0)
+ return ret;
+ }
+
+ pb = devm_kzalloc(&pdev->dev, sizeof(*pb), GFP_KERNEL);
+ if (!pb) {
+ dev_err(&pdev->dev, "no memory for state\n");
+ ret = -ENOMEM;
+ goto err_alloc;
+ }
+
+ __pwm0_gpio_setup();
+
+ pb->invert = data->invert;
+ pb->period = data->pwm_period_ns;
+ pb->notify = data->notify;
+ pb->notify_after = data->notify_after;
+ pb->check_fb = data->check_fb;
+ pb->lth_ns = data->lth_brightness * (data->pwm_period_ns / data->max_brightness);
+ pb->hth_ns = (data->max_brightness - data->hth_brightness) *
+ (data->pwm_period_ns / data->max_brightness);
+ pb->dev = &pdev->dev;
+
+ 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_alloc;
+ } else
+ dev_dbg(&pdev->dev, "got pwm for backlight\n");
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = data->max_brightness;
+ bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, pb,
+ &pwm_backlight_ops, &props);
+ if (IS_ERR(bl)) {
+ dev_err(&pdev->dev, "failed to register backlight\n");
+ ret = PTR_ERR(bl);
+ goto err_bl;
+ }
+
+ bl->props.brightness = data->dft_brightness;
+ //backlight_update_status(bl);
+
+ platform_set_drvdata(pdev, bl);
+ return 0;
+
+err_bl:
+ pwm_free(pb->pwm);
+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);
+ if (data->exit)
+ data->exit(&pdev->dev);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int pwm_backlight_suspend(struct device *dev)
+{
+ struct backlight_device *bl = dev_get_drvdata(dev);
+ struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+ if (pb->notify)
+ pb->notify(pb->dev, 0);
+
+ if (pb->invert) {
+ pwm_config(pb->pwm, pb->period, pb->period);
+ } else {
+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+ }
+
+ if (pb->notify_after)
+ pb->notify_after(pb->dev, 0);
+ return 0;
+}
+
+static int pwm_backlight_resume(struct device *dev)
+{
+ //struct backlight_device *bl = dev_get_drvdata(dev);
+ //backlight_update_status(bl);
+
+ __pwm0_gpio_setup();
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(pwm_backlight_pm_ops, pwm_backlight_suspend,
+ pwm_backlight_resume);
+
+#endif
+
+static void pwm_backlight_shutdown(struct platform_device *pdev)
+{
+ pwm_backlight_suspend(&pdev->dev);
+}
+
+static struct platform_driver pwm_backlight_driver = {
+ .driver = {
+ .name = "pwm-backlight",
+ .owner = THIS_MODULE,
+#ifdef CONFIG_PM
+ .pm = &pwm_backlight_pm_ops,
+#endif
+ },
+ .probe = pwm_backlight_probe,
+ .remove = pwm_backlight_remove,
+ .shutdown = pwm_backlight_shutdown,
+};
+
+module_platform_driver(pwm_backlight_driver);
+
+MODULE_DESCRIPTION("PWM based Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pwm-backlight");
+