> [...] > > diff --git a/Documentation/devicetree/bindings/lcd/lcd-pwrctrl.txt b/Documentation/devicetree/bindings/lcd/lcd-pwrctrl.txt > new file mode 100644 > index 0000000..941e2ff > --- /dev/null > +++ b/Documentation/devicetree/bindings/lcd/lcd-pwrctrl.txt > @@ -0,0 +1,39 @@ > +* Power controller for simple lcd panels > + > +Some LCD panels provide a simple control interface for the host system. The > +control mechanism would include a nRESET line connected to a gpio of the host > +system and a Vcc supply line which the host can optionally be controlled using > +a voltage regulator. Such simple panels do not support serial command > +interface (such as i2c or spi) or memory-mapped-io interface. > + > +Required properties: > +- compatible: should be 'lcd,powerctrl' > +- gpios: The GPIO number of the host system used to control the nRESET line. > + The format of the gpio specifier depends on the gpio controller of the > + host system. > + > +Optional properties: > +- lcd,pwrctrl-nreset-gpio-invert: When the nRESET line is asserted low, the > + lcd panel is reset and stays in reset mode as long as the nRESET line is > + asserted low. This is the default behaviour of most lcd panels. If a lcd > + panel requires the nRESET line to be asserted high for panel reset, then > + this property is used. Maybe use OF_GPIO_ACTIVE_LOW here instead. That would make active high the default but be a bit more consistent. > +- lcd,pwrctrl-min-uV: If a regulator controls the Vcc voltage of the lcd panel, > + this property specifies the minimum voltage the regulator should supply. > + The value of this property should in in micro-volts. > +- lcd,pwrctrl-max-uV: If a regulator controls the Vcc voltage of the lcd panel, > + this property specifies the maximum voltage the regulator should limit to > + on the Vcc line. The value of this property should in in micro-volts. The min and max voltage should rather be specified through the regulator constraints. > +- vcc-lcd-supply: phandle of the regulator that controls the vcc supply to > + the lcd panel. > + [...] > diff --git a/drivers/video/backlight/lcd_pwrctrl.c b/drivers/video/backlight/lcd_pwrctrl.c > new file mode 100644 > index 0000000..6f3110b > --- /dev/null > +++ b/drivers/video/backlight/lcd_pwrctrl.c > @@ -0,0 +1,231 @@ > [...] > +static int lcd_pwrctrl_set_power(struct lcd_device *lcd, int power) > +{ > + struct lcd_pwrctrl *lp = lcd_get_data(lcd); > + struct lcd_pwrctrl_data *pd = lp->pdata; > + int lcd_enable, lcd_reset; > + > + lcd_enable = (power == FB_BLANK_POWERDOWN || lp->suspended) ? 0 : 1; > + lcd_reset = (pd->invert) ? !lcd_enable : lcd_enable; > + > + if (IS_ERR(lp->regulator)) > + goto no_regulator; I wouldn't use a goto here. > + > + if (lcd_enable) { > + if ((pd->min_uV || pd->max_uV) && > + regulator_set_voltage(lp->regulator, > + pd->min_uV, pd->max_uV)) > + dev_info(lp->dev, > + "regulator voltage set failed\n"); > + if (regulator_enable(lp->regulator)) > + dev_info(lp->dev, "failed to enable regulator\n"); > + } else { > + regulator_disable(lp->regulator); > + } I think you have to make sure that the regulator enable and disable calls are balanced. > + > + no_regulator: > + gpio_direction_output(lp->pdata->gpio, lcd_reset); > + lp->power = power; > + return 0; > +} > + [...] > + > +#ifdef CONFIG_OF I think you can remove all the CONFIG_OF ifdefs, the of API should stub itself out. > +static void __devinit lcd_pwrctrl_parse_dt(struct device *dev, > + struct lcd_pwrctrl_data *pdata) > +{ > + struct device_node *np = dev->of_node; > + > + pdata->gpio = of_get_gpio(np, 0); > + if (of_get_property(np, "lcd,pwrctrl-nreset-gpio-invert", NULL)) > + pdata->invert = true; > + of_property_read_u32(np, "lcd,pwrctrl-min-uV", &pdata->min_uV); > + of_property_read_u32(np, "lcd,pwrctrl-max-uV", &pdata->max_uV); > +} > +#endif > + > +static int __devinit lcd_pwrctrl_probe(struct platform_device *pdev) > +{ > + struct lcd_pwrctrl *lp; > + struct lcd_pwrctrl_data *pdata = pdev->dev.platform_data; > + struct device *dev = &pdev->dev; > + int err; > + > +#ifdef CONFIG_OF > + if (dev->of_node) { > + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); > + if (!pdata) { > + dev_err(dev, "memory allocation for pdata failed\n"); > + return -ENOMEM; > + } > + lcd_pwrctrl_parse_dt(dev, pdata); > + } > +#endif > + > + if (!pdata) { > + dev_err(dev, "platform data not available\n"); > + return -EINVAL; > + } > + > + err = gpio_request(pdata->gpio, "LCD-nRESET"); > + if (err) { > + dev_err(dev, "gpio [%d] request failed\n", pdata->gpio); > + return err; > + } > + > + lp = devm_kzalloc(dev, sizeof(struct lcd_pwrctrl), GFP_KERNEL); > + if (!lp) { > + dev_err(dev, "memory allocation failed for private data\n"); > + return -ENOMEM; You are leaking the gpio here. > + } > + > + /* > + * If power to lcd and/or lcd interface is controlled using a regulator, > + * get the handle to the regulator for later use during power switching. > + */ > + lp->regulator = regulator_get(dev, "vcc-lcd"); > + if (IS_ERR(lp->regulator)) > + dev_info(dev, "could not find regulator\n"); > + > + lp->dev = dev; > + lp->pdata = pdata; > + lp->lcd = lcd_device_register(dev_name(dev), dev, lp, &lcd_pwrctrl_ops); > + if (IS_ERR(lp->lcd)) { > + dev_err(dev, "cannot register lcd device\n"); > + regulator_put(lp->regulator); And here. > + return PTR_ERR(lp->lcd); > + } > + > + platform_set_drvdata(pdev, lp); > + lcd_pwrctrl_set_power(lp->lcd, FB_BLANK_NORMAL); > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id lcd_pwrctrl_match[] = { > + { .compatible = "lcd,powerctrl", }, > + {}, > +}; MODULE_DEVICE_TABLE(...) > +#endif > +static struct platform_driver lcd_pwrctrl_driver = { > + .driver = { > + .name = "lcd-pwrctrl", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(lcd_pwrctrl_match), > + }, > + .probe = lcd_pwrctrl_probe, > + .remove = lcd_pwrctrl_remove, > + .suspend = lcd_pwrctrl_suspend, > + .resume = lcd_pwrctrl_resume, please use dev_pm_ops instead of the legacy callbacks > +}; > + > +static int __init lcd_pwrctrl_init(void) > +{ > + return platform_driver_register(&lcd_pwrctrl_driver); > +} > + > +static void __exit lcd_pwrctrl_cleanup(void) > +{ > + platform_driver_unregister(&lcd_pwrctrl_driver); > +} > + > +module_init(lcd_pwrctrl_init); > +module_exit(lcd_pwrctrl_cleanup); module_platform_driver(&lcd_pwrctrl_driver); > + > +MODULE_AUTHOR("Thomas Abraham <thomas.ab@xxxxxxxxxxx>"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:lcd-pwrctrl"); -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html