On Wed 2018-10-10 19:09:35, Lubomir Rintel wrote: > Strobe a GPIO line when the slave TX FIFO is filled. This is how the > Embedded Controller on an OLPC XO-1.75 machine, that happens to be a SPI > master, learns that it can initiate a transaction. > > Signed-off-by: Lubomir Rintel <[email protected]>
Acked-by: Pavel Machek <[email protected]> > --- > drivers/spi/spi-pxa2xx.c | 12 ++++++++++++ > drivers/spi/spi-pxa2xx.h | 3 +++ > 2 files changed, 15 insertions(+) > > diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c > index 3848842d68fd..a3b4b12c1077 100644 > --- a/drivers/spi/spi-pxa2xx.c > +++ b/drivers/spi/spi-pxa2xx.c > @@ -1079,6 +1079,9 @@ static int pxa2xx_spi_transfer_one(struct > spi_controller *master, > if (spi_controller_is_slave(master)) { > while (drv_data->write(drv_data)) > ; > + gpiod_set_value(drv_data->gpiod_ready, 1); > + udelay(1); > + gpiod_set_value(drv_data->gpiod_ready, 0); > } > > /* > @@ -1784,6 +1787,15 @@ static int pxa2xx_spi_probe(struct platform_device > *pdev) > } > } > > + if (platform_info->is_slave) { > + drv_data->gpiod_ready = devm_gpiod_get_optional(dev, > + "ready", GPIOD_OUT_LOW); > + if (IS_ERR(drv_data->gpiod_ready)) { > + status = (int)PTR_ERR(drv_data->gpiod_ready); > + goto out_error_clock_enabled; > + } > + } > + > pm_runtime_set_autosuspend_delay(&pdev->dev, 50); > pm_runtime_use_autosuspend(&pdev->dev); > pm_runtime_set_active(&pdev->dev); > diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h > index 513c53aaeab2..4e324da66ef7 100644 > --- a/drivers/spi/spi-pxa2xx.h > +++ b/drivers/spi/spi-pxa2xx.h > @@ -64,6 +64,9 @@ struct driver_data { > > /* GPIOs for chip selects */ > struct gpio_desc **cs_gpiods; > + > + /* Optional slave FIFO ready signal */ > + struct gpio_desc *gpiod_ready; > }; > > struct chip_data { -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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