redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

spi: sun6i: Add support for GPIO chip select lines 

Add a setup function that can be used to support using generic GPIO
lines for the chip select.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
alistair/sensors
Alistair Francis 2020-05-01 18:04:26 -07:00
parent 4782adfe63
commit b10d5c2c08
1 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/spi/spi-sun6i.c
View File

@ -10,6 +10,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@ -171,6 +172,31 @@ static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len)
}
}
static int sun6i_spi_setup(struct spi_device *spi)
{
int ret;
/* sanity check for native cs */
if (spi->mode & SPI_NO_CS)
return 0;
if (gpio_is_valid(spi->cs_gpio)) {
/* with gpio-cs set the GPIO to the correct level
* and as output (in case the dt has the gpio not configured
* as output but native cs)
*/
ret = gpio_direction_output(spi->cs_gpio,
(spi->mode & SPI_CS_HIGH) ? 0 : 1);
if (ret)
dev_err(&spi->dev,
"could not set gpio %i as output: %i\n",
spi->cs_gpio, ret);
return ret;
}
return 0;
}
static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
{
struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
@ -470,6 +496,7 @@ static int sun6i_spi_probe(struct platform_device *pdev)
master->max_speed_hz = 100 * 1000 * 1000;
master->min_speed_hz = 3 * 1000;
master->setup = sun6i_spi_setup;
master->set_cs = sun6i_spi_set_cs;
master->transfer_one = sun6i_spi_transfer_one;
master->num_chipselect = 4;