The patch spi: pxa2xx: Add ready signal has been applied to the spi tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 77d33897c68d56797a3201e06bdf10e2094a96d6 Mon Sep 17 00:00:00 2001 From: Lubomir Rintel <lkundrak@xxxxx> Date: Tue, 13 Nov 2018 11:22:27 +0100 Subject: [PATCH] spi: pxa2xx: Add ready signal 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 <lkundrak@xxxxx> Tested-by: Pavel Machek <pavel@xxxxxx> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/spi/spi-pxa2xx.c | 16 +++++++++++++++- drivers/spi/spi-pxa2xx.h | 3 +++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index a057c3be7e3b..69b221e34b2d 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -1081,6 +1081,11 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *master, if (spi_controller_is_slave(master)) { while (drv_data->write(drv_data)) ; + if (drv_data->gpiod_ready) { + gpiod_set_value(drv_data->gpiod_ready, 1); + udelay(1); + gpiod_set_value(drv_data->gpiod_ready, 0); + } } /* @@ -1778,7 +1783,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) if (PTR_ERR(gpiod) == -ENOENT) continue; - status = (int)PTR_ERR(gpiod); + status = PTR_ERR(gpiod); goto out_error_clock_enabled; } else { drv_data->cs_gpiods[i] = gpiod; @@ -1786,6 +1791,15 @@ 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 = 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 { -- 2.19.1