Am Sat, 7 Feb 2015 12:43:29 +0100 schrieb Maxime Ripard <[email protected]>:
> On Fri, Feb 06, 2015 at 11:28:13PM +0100, [email protected] > wrote: > > From: Thomas Niederprüm <[email protected]> > > > > This patch adds sysfs handles to enable userspace control over the > > display contrast as well as the dim mode. The handles are available > > as "contrast" and "dim" in the framebuffers sysfs domain. > > > > Signed-off-by: Thomas Niederprüm <[email protected]> > > --- > > drivers/video/fbdev/ssd1307fb.c | 88 > > ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 87 > > insertions(+), 1 deletion(-) > > > > diff --git a/drivers/video/fbdev/ssd1307fb.c > > b/drivers/video/fbdev/ssd1307fb.c index b38315d..02931c7 100644 > > --- a/drivers/video/fbdev/ssd1307fb.c > > +++ b/drivers/video/fbdev/ssd1307fb.c > > @@ -33,6 +33,7 @@ > > #define SSD1307FB_CONTRAST 0x81 > > #define SSD1307FB_CHARGE_PUMP 0x8d > > #define SSD1307FB_SEG_REMAP_ON 0xa1 > > +#define SSD1307FB_DISPLAY_DIM 0xac > > #define SSD1307FB_DISPLAY_OFF 0xae > > #define SSD1307FB_SET_MULTIPLEX_RATIO 0xa8 > > #define SSD1307FB_DISPLAY_ON 0xaf > > @@ -43,6 +44,9 @@ > > #define SSD1307FB_SET_COM_PINS_CONFIG 0xda > > #define SSD1307FB_SET_VCOMH 0xdb > > > > +#define MIN_CONTRAST 0 > > +#define MAX_CONTRAST 255 > > + > > #define BITSPERPIXEL 1 > > #define DELAYDIVIDER 20 > > > > @@ -69,6 +73,7 @@ struct ssd1307fb_par { > > u32 dclk_div; > > u32 dclk_frq; > > struct ssd1307fb_deviceinfo *device_info; > > + u32 dim; > > struct i2c_client *client; > > u32 height; > > struct fb_info *info; > > @@ -515,6 +520,79 @@ static const struct of_device_id > > ssd1307fb_of_match[] = { }; > > MODULE_DEVICE_TABLE(of, ssd1307fb_of_match); > > > > +static ssize_t show_contrast(struct device *device, > > + struct device_attribute *attr, char > > *buf) +{ > > + struct fb_info *info = dev_get_drvdata(device); > > + struct ssd1307fb_par *par = info->par; > > + > > + return snprintf(buf, PAGE_SIZE, "%d\n", par->contrast); > > +} > > + > > +static ssize_t store_contrast(struct device *device, > > + struct device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + struct fb_info *info = dev_get_drvdata(device); > > + struct ssd1307fb_par *par = info->par; > > + unsigned long contrastval; > > + int ret; > > + > > + ret = kstrtoul(buf, 0, &contrastval); > > + if (ret < 0) > > + return ret; > > + > > + par->contrast = max(min(contrastval, > > + (ulong)MAX_CONTRAST), (ulong)MIN_CONTRAST); > > + > > + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST); > > + ret = ret & ssd1307fb_write_cmd(par->client, > > par->contrast); > > + if (ret < 0) > > + return ret; > > + > > + return count; > > +} > > + > > + > > +static ssize_t show_dim(struct device *device, > > + struct device_attribute *attr, char > > *buf) +{ > > + struct fb_info *info = dev_get_drvdata(device); > > + struct ssd1307fb_par *par = info->par; > > + > > + return snprintf(buf, PAGE_SIZE, "%d\n", par->dim); > > +} > > + > > +static ssize_t store_dim(struct device *device, > > + struct device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + struct fb_info *info = dev_get_drvdata(device); > > + struct ssd1307fb_par *par = info->par; > > + unsigned long dimval; > > + int ret; > > + > > + ret = kstrtoul(buf, 0, &dimval); > > + if (ret < 0) > > + return ret; > > + > > + par->dim = max(min(dimval, (ulong)1), (ulong)0); > > + if (par->dim) > > + ret = ssd1307fb_write_cmd(par->client, > > SSD1307FB_DISPLAY_DIM); > > + else > > + ret = ssd1307fb_write_cmd(par->client, > > SSD1307FB_DISPLAY_ON); > > + if (ret < 0) > > + return ret; > > + > > + return count; > > +} > > + > > +static struct device_attribute device_attrs[] = { > > + __ATTR(contrast, S_IRUGO|S_IWUSR, show_contrast, > > store_contrast), > > + __ATTR(dim, S_IRUGO|S_IWUSR, show_dim, store_dim), > > + > > +}; > > + > > I would have thought this was something accessible through the > framebuffer ioctl. > > Apparently it's not, at least for the contrast, so maybe it should be > added there, instead of doing it for a single driver? I think the contrast setting for an OLED display is much like the backlight setting for LCD panel. Since there is also no ioctl to set the backlight of an LCD I wonder if the contrast of an OLED should have one. > > (oh, and btw, every sysfs file should be documented in > Documentation/ABI) > > > static int ssd1307fb_probe(struct i2c_client *client, > > const struct i2c_device_id *id) > > { > > @@ -523,7 +601,7 @@ static int ssd1307fb_probe(struct i2c_client > > *client, u32 vmem_size; > > struct ssd1307fb_par *par; > > u8 *vmem; > > - int ret; > > + int ret, i; > > > > if (!node) { > > dev_err(&client->dev, "No device tree data > > found!\n"); @@ -650,6 +728,14 @@ static int ssd1307fb_probe(struct > > i2c_client *client, goto reset_oled_error; > > > > ret = register_framebuffer(info); > > + > > + for (i = 0; i < ARRAY_SIZE(device_attrs); i++) > > + ret = device_create_file(info->dev, > > &device_attrs[i]); + > > + if (ret) { > > + dev_err(&client->dev, "Couldn't register sysfs > > nodes\n"); > > + } > > + > > sysfs_create_groups does pretty much that already. I'll have a look at it. > > And don't forget to remove these files in the .remove() Good point! :) > > > if (ret) { > > dev_err(&client->dev, "Couldn't register the > > framebuffer\n"); goto panel_init_error; > > -- > > 2.1.1 > > > > Maxime > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
