iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

spi: gpio: Add SPI_MASTER_GPIO_SS flag

Browse Source 
The GPIO SPI master has some code in its local CS
callback to set the initial sck GPIO value. This was
lost in the commit converting it to use SPI core
GPIO handling as this callback isn't called if the
internal GPIO handling is active.

Add the special SPI_MASTER_GPIO_SS to ascertain it
gets called anyway so we get the initial SCK setting
right. There is some platform provided GPIO handling
there as well but this will be skipped as the cs_gpios
will be NULL.

My test targets seem not to care about the initial
SCK value so I am uncertain if this is a regression,
but to preserve the previous semantic we better do
this.

Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Fixes: 249e2632dcd0 ("spi: gpio: Don't request CS GPIO in DT use-case")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190716204651.7743-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Linus Walleij 2019-07-16 22:46:51 +02:00 committed by Mark Brown
parent d6b197a148
commit 2922d1cc16
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/spi/spi-gpio.c
View File

@ -410,6 +410,12 @@ static int spi_gpio_probe(struct platform_device *pdev)
bb = &spi_gpio->bitbang;
bb->master = master;
/*
* There is some additional business, apart from driving the CS GPIO
* line, that we need to do on selection. This makes the local
* callback for chipselect always get called.
*/
master->flags |= SPI_MASTER_GPIO_SS;
bb->chipselect = spi_gpio_chipselect;
bb->set_line_direction = spi_gpio_set_direction;