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| author | Jyri Sarha <jsarha@ti.com> | 2017-02-08 16:43:59 +0100 |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> | 2017-02-08 16:43:59 +0100 |
| commit | fdde1a8148d81617582c138cd1fbdc4594d4c941 (patch) | |
| tree | 9e76f4eef6b4b0944288897faab4d65525ecae74 /drivers/video/fbdev | |
| parent | fbdev: ssd1307fb: Remove reset-active-low from the DT binding document (diff) | |
| download | linux-fdde1a8148d81617582c138cd1fbdc4594d4c941.tar.xz linux-fdde1a8148d81617582c138cd1fbdc4594d4c941.zip | |
fbdev: ssd1307fb: Make reset gpio devicetree property optional
Make reset gpio devicetree property optional. Depending on the board
designing there may not be a dedicated gpio for resetting the
display. Without a proper reset there may be some junk in the display
memory at probe time, so in such a case the display memory is cleared
before turning it on. The devicetree binding document is also updated.
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Benoît Cousson <bcousson@baylibre.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'drivers/video/fbdev')
| -rw-r--r-- | drivers/video/fbdev/ssd1307fb.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index 8ffaaeeb2f84..89372af7bc5b 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -439,6 +439,10 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) if (ret < 0) return ret; + /* Clear the screen if we could not give reset at probe time */ + if (!par->reset) + ssd1307fb_update_display(par); + /* Turn on the display */ ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON); if (ret < 0) @@ -561,7 +565,8 @@ static int ssd1307fb_probe(struct i2c_client *client, par->device_info = of_device_get_match_data(&client->dev); - par->reset = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_LOW); + par->reset = devm_gpiod_get_optional(&client->dev, "reset", + GPIOD_OUT_LOW); if (IS_ERR(par->reset)) { dev_err(&client->dev, "failed to get reset gpio: %ld\n", PTR_ERR(par->reset)); @@ -645,11 +650,13 @@ static int ssd1307fb_probe(struct i2c_client *client, i2c_set_clientdata(client, info); - /* Reset the screen */ - gpiod_set_value(par->reset, 0); - udelay(4); - gpiod_set_value(par->reset, 1); - udelay(4); + if (par->reset) { + /* Reset the screen */ + gpiod_set_value(par->reset, 0); + udelay(4); + gpiod_set_value(par->reset, 1); + udelay(4); + } ret = ssd1307fb_init(par); if (ret) |