Unverified Commit 77d33897 authored by Lubomir Rintel's avatar Lubomir Rintel Committed by Mark Brown
Browse files

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: default avatarLubomir Rintel <lkundrak@v3.sk>
Tested-by: default avatarPavel Machek <pavel@ucw.cz>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 8ae13d0b

drivers/spi/spi-pxa2xx.c

+15 −1
Original line number Diff line number Diff line
@@ -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);

drivers/spi/spi-pxa2xx.h

+3 −0
Original line number Diff line number Diff line
@@ -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 {

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