kernel/drivers/video/fbdev/ssd1307fb.c, branch linux-5.1.y

video: ssd1307fb: Do not hard code active-low reset sequence

2019-02-08T18:24:48Z

The SSD130x OLED display reset signal is active low. Now the reset sequence is implemented in such a way that users are forced to define reset-gpios as GPIO_ACTIVE_HIGH in DT to make the reset work. Do not hard code the active-low sequence into the driver but instead allow the user to specify the gpio as GPIO_ACTIVE_LOW to reflect the real world. Reviewed-by: Rob Herring Reviewed-by: Alexandre Belloni Cc: Shawn Guo Cc: Fabio Estevam Cc: Maxime Ripard , Signed-off-by: Michal Vokáč Signed-off-by: Bartlomiej Zolnierkiewicz

Revert "video: ssd1307fb: Do not hard code active-low reset sequence"

2018-10-09T13:18:42Z

This reverts commit 9827f26374fb85e1811f2adbcc25c8a3992dbe7f. On 10/09/2018 02:20 AM, Shawn Guo wrote: > Well, it means the change breaks the ABI between kernel and device tree, > e.g. the new kernel will not work with existing/installed DTBs. Revert the change until DTB compatibility issue is resolved. Signed-off-by: Bartlomiej Zolnierkiewicz

video: ssd1307fb: Do not hard code active-low reset sequence

2018-10-08T10:57:37Z

The SSD130x OLED display reset signal is active low. Now the reset sequence is implemented in such a way that users are forced to define reset-gpios as GPIO_ACTIVE_HIGH in DT to make the reset work. Do not hard code the active-low sequence into the driver but instead allow the user to specify the gpio as GPIO_ACTIVE_LOW to reflect the real world. Signed-off-by: Michal Vokáč Cc: Shawn Guo Cc: Rob Herring Signed-off-by: Bartlomiej Zolnierkiewicz

video: ssd1307fb: Use gpiod_set_value_cansleep() for reset

2018-10-08T10:57:36Z

The reset signal can be produced by GPIO expander that can sleep. In that case the probe function fails. Allow using GPIO expanders for the reset signal by using the non-atomic gpiod_set_value_cansleep() function. Signed-off-by: Michal Vokáč Reviewed-by: Fabio Estevam Cc: Shawn Guo Cc: Rob Herring Signed-off-by: Bartlomiej Zolnierkiewicz

video: ssd1307fb: Improve a size determination in ssd1307fb_probe()

2018-03-28T14:34:28Z

Replace the specification of a data structure by a pointer dereference as the parameter for the operator "sizeof" to make the corresponding size determination a bit safer according to the Linux coding style convention. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Cc: Arnd Bergmann Cc: Bastian Stender Cc: Jyri Sarha Cc: Tomi Valkeinen Signed-off-by: Bartlomiej Zolnierkiewicz

fbdev/ssd1307fb: fix optional VBAT support

2017-04-07T15:28:23Z

SSD1306 needs VBAT when it is wired in charge pump configuration only. Other controllers of the SSD1307 family do not need it at all. This was introduced by commit ba14301e0356 ("fbdev/ssd1307fb: add support to enable VBAT"). Without VBAT configuration the driver now fails with: failed to get VBAT regulator: -19 This is caused by misinterpretation of devm_regulator_get_optional which "returns a struct regulator corresponding to the regulator producer or IS_ERR() condition". Handle -ENODEV without bailing out and making VBAT support really optional. Signed-off-by: Bastian Stender Cc: Tomi Valkeinen Cc: Jyri Sarha Cc: Roger Quadros [b.zolnierkie: minor fixups] Signed-off-by: Bartlomiej Zolnierkiewicz

fbdev: ssd1307fb: include linux/gpio/consumer.h

2017-02-20T12:51:07Z

Changing this driver to the gpiod API requires the use of the new-style header, depending on the configuration: drivers/video/fbdev/ssd1307fb.c: In function 'ssd1307fb_probe': drivers/video/fbdev/ssd1307fb.c:569:15: error: implicit declaration of function 'devm_gpiod_get_optional';did you mean 'devm_regulator_get_optional'? [-Werror=implicit-function-declaration] drivers/video/fbdev/ssd1307fb.c:570:11: error: 'GPIOD_OUT_LOW' undeclared (first use in this function) Fixes: 72db33355c14 ("fbdev: ssd1307fb: Start to use gpiod API for reset gpio") Cc: Tomi Valkeinen Cc: Jyri Sarha Cc: LABBE Corentin Signed-off-by: Arnd Bergmann Signed-off-by: Bartlomiej Zolnierkiewicz

fbdev/ssd1307fb: clear screen in probe

2017-02-08T15:44:00Z

SSD1306 does not clear the panel's framebuffer automatically, even if a HW reset happens, so we need to do that at probe time before enabling the panel. Cc: Rob Herring Cc: Maxime Ripard Cc: Benoît Cousson Signed-off-by: Tomi Valkeinen Signed-off-by: Jyri Sarha Signed-off-by: Bartlomiej Zolnierkiewicz

fbdev/ssd1307fb: add support to enable VBAT

2017-02-08T15:43:59Z

SSD1306 needs VBAT when it is wired in charge pump configuration. This patch adds support to the driver to enable VBAT regulator at init time. Cc: Rob Herring Cc: Maxime Ripard Cc: Benoît Cousson Signed-off-by: Tomi Valkeinen Reviewed-by: Roger Quadros Signed-off-by: Jyri Sarha Signed-off-by: Bartlomiej Zolnierkiewicz

fbdev: ssd1307fb: Make reset gpio devicetree property optional

2017-02-08T15:43:59Z

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 Cc: Tomi Valkeinen Cc: Maxime Ripard Cc: Benoît Cousson Signed-off-by: Jyri Sarha Signed-off-by: Bartlomiej Zolnierkiewicz