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author | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
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committer | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
commit | 97327692361306d1e6259021bc425e32832fdb50 (patch) | |
tree | fe9088f3248ec61e24f404f21b9793cb644b7f01 /drivers/video/backlight/pwm_bl.c | |
parent | 2d05a8f663478a44e088d122e0d62109bbc801d0 (diff) | |
parent | a3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff) | |
download | FOSSEE-netbook-kernel-source-97327692361306d1e6259021bc425e32832fdb50.tar.gz FOSSEE-netbook-kernel-source-97327692361306d1e6259021bc425e32832fdb50.tar.bz2 FOSSEE-netbook-kernel-source-97327692361306d1e6259021bc425e32832fdb50.zip |
dirty fix to merging
Diffstat (limited to 'drivers/video/backlight/pwm_bl.c')
-rw-r--r-- | drivers/video/backlight/pwm_bl.c | 259 |
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"); + |