Add a setup function that can be used to support using generic GPIO
lines for the chip select.
Signed-off-by: Alistair Francis <[email protected]>
---
drivers/spi/spi-sun6i.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index ec7967be9e2f..fd4e19434942 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -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;
--
2.26.2
Hi Alistair,
On Wed, May 6, 2020 at 3:41 AM Alistair Francis <[email protected]> wrote:
> Add a setup function that can be used to support using generic GPIO
> lines for the chip select.
>
> Signed-off-by: Alistair Francis <[email protected]>
> ---
> drivers/spi/spi-sun6i.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
> index ec7967be9e2f..fd4e19434942 100644
> --- a/drivers/spi/spi-sun6i.c
> +++ b/drivers/spi/spi-sun6i.c
> @@ -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;
Can't you just set
master->use_gpio_descriptors = true;
instead and be done with it?
Then drivers/spi/spi.c:spi_get_gpio_descs() will configure the GPIO line
as output for you.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On Wed, May 6, 2020, at 1:27 AM, Geert Uytterhoeven wrote:
> Hi Alistair,
>
> On Wed, May 6, 2020 at 3:41 AM Alistair Francis <[email protected]> wrote:
> > Add a setup function that can be used to support using generic GPIO
> > lines for the chip select.
> >
> > Signed-off-by: Alistair Francis <[email protected]>
> > ---
> > drivers/spi/spi-sun6i.c | 27 +++++++++++++++++++++++++++
> > 1 file changed, 27 insertions(+)
> >
> > diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
> > index ec7967be9e2f..fd4e19434942 100644
> > --- a/drivers/spi/spi-sun6i.c
> > +++ b/drivers/spi/spi-sun6i.c
> > @@ -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;
>
> Can't you just set
>
> master->use_gpio_descriptors = true;
>
> instead and be done with it?
> Then drivers/spi/spi.c:spi_get_gpio_descs() will configure the GPIO line
> as output for you.
Yep, it looks like that works. Sending a v2.
Alistair
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
>