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authorLubomir Rintel <lkundrak@v3.sk>2018-11-13 13:22:27 +0300
committerMark Brown <broonie@kernel.org>2018-11-13 21:02:09 +0300
commit77d33897c68d56797a3201e06bdf10e2094a96d6 (patch)
tree8b762b220b3a3b7d72d2987fc844295dfb06cb98 /drivers/spi/spi-pxa2xx.c
parent8ae13d0b0d4bb4af99bec8c50152f0c8f5cbcc06 (diff)
downloadlinux-77d33897c68d56797a3201e06bdf10e2094a96d6.tar.xz
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@v3.sk> Tested-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
-rw-r--r--drivers/spi/spi-pxa2xx.c16
1 files changed, 15 insertions, 1 deletions
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);