Re: [PATCH/HP7XX] - Add combined LCD / BL driver for platform HP Jornada 7xx handhelds

From: Russell King - ARM Linux
Date: Wed Feb 06 2008 - 11:45:25 EST


On Wed, Feb 06, 2008 at 05:33:41PM +0100, Kristoffer Ericson wrote:
> Oki, here is attempt #2 (btw, new mail or just keep thread?)

Probably better to keep the thread. More comments 8)

> +struct jornada_bllcd_device {
> + struct backlight_device *jorn_backlight_device;
> + struct lcd_device *jorn_lcd_device;

We're inside a jornada file. Do these "jorn_" prefixes add anything
useful that the reader doesn't already know?

> +static int jornada_bl_update_status(struct backlight_device *dev)
> +{
> + int ret = 0;
> +
> + jornada_ssp_start();
> +
> + if (dev->props.power != FB_BLANK_UNBLANK ||
> + dev->props.fb_blank != FB_BLANK_UNBLANK) {
> + ret = jornada_ssp_inout(BRIGHTNESSOFF);
> + if (ret == -ETIMEDOUT)
> + printk(KERN_ERR "jornada720_bl: \
> + BrightnessOff timeout\n");
> + /* backlight off */
> + PPSR &= ~PPC_LDD1;
> + PPDR |= PPC_LDD1;

Look at the above 5 lines. What are your expectations if ret != -ETIMEDOUT?
If C were python you'd have one behaviour due to the indent...

> +
> + } else { /* backlight on */

Too many spaces.

> + PPSR |= PPC_LDD1;
> + if ((jornada_ssp_inout(SETBRIGHTNESS)) == TXDUMMY) {
> + /* send brightness value (0 is max, 255 lowest) */
> + if (jornada_ssp_byte(JORNADA_BL_MAX_BRIGHTNESS -
> + dev->props.brightness) != -ETIMEDOUT)
> + ret = (JORNADA_BL_MAX_BRIGHTNESS -
> + dev->props.brightness);
> + } else
> + printk(KERN_ERR "jornada720_bl: \
> + SetBrightness timeout\n");
> + }

If this corresponds with the "} else {" line, it should have one tab. Plus
the above indented code section should probably have one less indentation.

> + jornada_ssp_end();
> +
> + return ret;
> +}
> +
> +/*
> + * LCD HANDLING FUNCTIONS
> + */
> +static int jornada_lcd_set_contrast(struct lcd_device *pdev, int contrast)
> +{
> + int ret = 0;
> +
> + jornada_ssp_start();
> +
> + ret = jornada_ssp_inout(SETCONTRAST);
> +
> + if (ret == -ETIMEDOUT)
> + printk(KERN_ERR "jornada_lcd: failure to set contrast\n");
> + else

Space before 'else' not required.

> + ret = jornada_ssp_byte(contrast);
> +
> + jornada_ssp_end();
> +
> + return ret;
> +}
> +
> +static int jornada_lcd_set_power(struct lcd_device *pdev, int power)
> +{
> + if (power != FB_BLANK_UNBLANK) {
> + /* turn off LCD */
> + PPSR &= ~PPC_LDD2;
> + PPDR |= PPC_LDD2;
> + } else {
> + /* turn on LCD */
> + PPSR |= PPC_LDD2;
> + }

Wrongly placed }

> +
> + return 0;
> +}
> +
> +static int jornada_lcd_get_power(struct lcd_device *pdev)
> +{
> + if (PPSR & PPC_LDD2)
> + return FB_BLANK_UNBLANK;
> + else
> + return FB_BLANK_POWERDOWN;
> +}
> +
> +static int jornada_lcd_get_contrast(struct lcd_device *pdev)
> +{
> + int ret;
> +
> + /* Don't set contrast on off powerd LCD */
> + if (jornada_lcd_get_power(pdev) != FB_BLANK_UNBLANK)
> + return 0;
> +
> + jornada_ssp_start();
> +
> + ret = jornada_ssp_inout(GETCONTRAST);
> + if (ret != -ETIMEDOUT)
> + ret = jornada_ssp_inout(TXDUMMY);
> + else {
> + printk(KERN_ERR "jornada_lcd: getcontrast failed!\n");
> + ret = JORNADA_BL_MAX_BRIGHTNESS + 1;
> + }
> +
> + jornada_ssp_end();
> +
> + return ret;
> +}
> +
> +static struct backlight_ops jornada_bl_ops = {
> + .get_brightness = jornada_bl_get_brightness,
> + .update_status = jornada_bl_update_status,
> +};
> +
> +static struct lcd_ops jornada_lcd_ops = {
> + .get_contrast = jornada_lcd_get_contrast,
> + .set_contrast = jornada_lcd_set_contrast,
> + .get_power = jornada_lcd_get_power,
> + .set_power = jornada_lcd_set_power,
> +};
> +
> +static int jornada_bl_probe(struct platform_device *pdev)
> +{
> + struct jornada_bllcd_device *bllcd;
> +
> + bllcd = kzalloc(sizeof(*bllcd), GFP_KERNEL);
> + if (bllcd == NULL)
> + return -ENOMEM;
> +
> + /* bl driver - name must match fb driver name */
> + bllcd->jorn_backlight_device = backlight_device_register(S1D_DEVICENAME,
> + &pdev->dev, NULL, &jornada_bl_ops);
> +
> + if (IS_ERR(bllcd->jorn_backlight_device)) {
> + kfree(bllcd);
> + return PTR_ERR(bllcd->jorn_backlight_device);

Access after free. Bad bad bad.

> + }
> +
> + /* lcd driver */
> + bllcd->jorn_lcd_device = lcd_device_register(S1D_DEVICENAME,
> + &pdev->dev, NULL, &jornada_lcd_ops);
> + if (IS_ERR(bllcd->jorn_lcd_device)) {
> + kfree(bllcd);
> + return PTR_ERR(bllcd->jorn_lcd_device);

Access after free. Bad bad bad.

> + }
> +
> + jornada_lcd_set_contrast(bllcd->jorn_lcd_device,
> + JORNADA_LCD_DEFAULT_CONTRAST);
> + jornada_lcd_set_power(bllcd->jorn_lcd_device,
> + FB_BLANK_UNBLANK);
> +
> + msleep(100);
> +
> + bllcd->jorn_backlight_device->props.power
> + = FB_BLANK_UNBLANK;
> + bllcd->jorn_backlight_device->props.brightness
> + = JORNADA_BL_DEFAULT_BRIGHTNESS;

If you get rid of the "jorn_" prefix, can these be on one line?

> + jornada_bl_update_status(bllcd->jorn_backlight_device);
> +
> + platform_set_drvdata(pdev, bllcd);
> + printk(KERN_INFO "HP Jornada 7xx Backlight/LCD driver activated\n");
> +
> + return 0;
> +}
> +
> +static int jornada_bl_remove(struct platform_device *pdev)
> +{
> + struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
> +
> + bllcd->jorn_backlight_device->props.power = FB_BLANK_POWERDOWN;
> + bllcd->jorn_backlight_device->props.brightness = 0;
> + bllcd->jorn_backlight_device->props.max_brightness = 0;
> +
> + backlight_device_unregister(bllcd->jorn_backlight_device);
> + lcd_device_unregister(bllcd->jorn_lcd_device);

Leaves bllcd allocated - memory leak.

> +
> + return 0;
> +}
> +
> +static int jornada_bl_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> + struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
> +
> + bllcd->jorn_backlight_device->props.power = FB_BLANK_POWERDOWN;
> + bllcd->jorn_backlight_device->props.brightness = 0;
> + bllcd->jorn_backlight_device->props.max_brightness = 0;
> + jornada_bl_update_status(bllcd->jorn_backlight_device);
> +
> + jornada_lcd_set_power(bllcd->jorn_lcd_device, FB_BLANK_POWERDOWN);
> +
> + return 0;
> +}
> +
> +static int jornada_bl_resume(struct platform_device *pdev)
> +{
> + struct jornada_bllcd_device *bllcd = platform_get_drvdata(pdev);
> +
> + bllcd->jorn_backlight_device->props.power
> + = FB_BLANK_UNBLANK;
> + bllcd->jorn_backlight_device->props.brightness
> + = JORNADA_BL_DEFAULT_BRIGHTNESS;
> + bllcd->jorn_backlight_device->props.max_brightness
> + = JORNADA_BL_MAX_BRIGHTNESS;
> + jornada_bl_update_status(bllcd->jorn_backlight_device);
> +
> + jornada_lcd_set_power(bllcd->jorn_lcd_device, FB_BLANK_UNBLANK);
> +
> + return 0;
> +}
> +
> +static struct platform_driver jornada_bl_driver = {
> + .probe = jornada_bl_probe,
> + .remove = jornada_bl_remove,
> +#ifdef CONFIG_PM
> + .suspend = jornada_bl_suspend,
> + .resume = jornada_bl_resume,
> +#endif
> + .driver = {
> + .name = "jornada_bllcd",

a tab, not 4 spaces.

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