linux_dsm_epyc7002/drivers/video/backlight
Robert Jarzmik 2023b0524a backlight: tdo24m: Fix the SPI CS between transfers
Currently the LCD display (TD035S) on the cm-x300 platform is broken and
remains blank.

The TD0245S specification requires that the chipselect is toggled
between commands sent to the panel. This was also the purpose of the
former patch of commit f64dcac0b1 ("backlight: tdo24m: ensure chip
select changes between transfers").

Unfortunately, the "cs_change" field of a SPI transfer is
misleading. Its true meaning is that for a SPI message holding multiple
transfers, the chip select is toggled between each transfer, but for the
last transfer it remains asserted.

In this driver, all the SPI messages contain exactly one transfer, which
means that each transfer is the last of its message, and as a
consequence the chip select is never toggled.

Actually, there was a second bug hidding the first one, hence the
problem was not seen until v4.6. This problem was fixed by commit
a52db659c7 ("spi: pxa2xx: Fix cs_change management") for PXA based
boards.

This fix makes the TD035S work again on a cm-x300 board. The same
applies to other PXA boards, ie. corgi and tosa.

Fixes: a52db659c7 ("spi: pxa2xx: Fix cs_change management")
Reported-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-01-08 09:21:57 +00:00
..
88pm860x_bl.c
aat2870_bl.c
adp5520_bl.c
adp8860_bl.c backlight: adp8860: Move header file out of I2C realm 2017-07-06 08:56:08 +01:00
adp8870_bl.c video: adp8870: move header file out of I2C realm 2017-07-06 08:58:39 +01:00
ams369fg06.c
apple_bl.c backlight: apple_bl: Deprecate pci_get_bus_and_slot() 2017-12-20 13:47:05 +00:00
arcxcnn_bl.c
as3711_bl.c
backlight.c backlight: Report error on failure 2017-05-30 09:27:53 +01:00
bd6107.c
corgi_lcd.c backlight: tdo24m: Fix the SPI CS between transfers 2018-01-08 09:21:57 +00:00
cr_bllcd.c
da903x_bl.c
da9052_bl.c
ep93xx_bl.c
generic_bl.c
gpio_backlight.c backlight: gpio_backlight: Delete pdata inversion 2017-08-07 17:11:28 +01:00
hp680_bl.c
hx8357.c
ili922x.c backlight: ili922x: Remove redundant variable len 2017-11-08 10:43:49 +00:00
ili9320.c
ili9320.h
ipaq_micro_bl.c
jornada720_bl.c
jornada720_lcd.c
kb3886_bl.c dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
Kconfig
l4f00242t03.c
lcd.c
ld9040_gamma.h
ld9040.c
lm3533_bl.c
lm3630a_bl.c backlight: lm3630a: Bump REG_MAX value to 0x50 instead of 0x1F 2017-07-17 13:27:06 +01:00
lm3639_bl.c
lms283gf05.c
lms501kf03.c
locomolcd.c
lp855x_bl.c
lp8788_bl.c
ltv350qv.c
ltv350qv.h
lv5207lp.c
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
max8925_bl.c
omap1_bl.c
ot200_bl.c
pandora_bl.c mfd: twl: Move header file out of I2C realm 2017-09-04 14:41:02 +01:00
pcf50633-backlight.c
platform_lcd.c
pm8941-wled.c
pwm_bl.c backlight: pwm_bl: Fix overflow condition 2017-10-13 10:41:20 +01:00
s6e63m0_gamma.h
s6e63m0.c
sky81452-backlight.c
tdo24m.c backlight: tdo24m: Fix the SPI CS between transfers 2018-01-08 09:21:57 +00:00
tosa_bl.c
tosa_lcd.c backlight: tdo24m: Fix the SPI CS between transfers 2018-01-08 09:21:57 +00:00
tps65217_bl.c - Fix-ups 2017-11-16 10:36:46 -08:00
vgg2432a4.c
wm831x_bl.c