| Message ID | 20200506014135.2941967-1-alistair@alistair23.me (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | spi: sun6i: Add support for GPIO chip select lines | expand |
Hi Alistair, On Wed, May 6, 2020 at 3:41 AM Alistair Francis <alistair@alistair23.me> wrote: > 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> > --- > 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
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 <alistair@alistair23.me> wrote: > > 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> > > --- > > 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 -- geert@linux-m68k.org > > 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 >
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;
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> --- drivers/spi/spi-sun6i.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)