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From: Lubomir Rintel <lkundrak@v3.sk>
To: Mark Brown <broonie@kernel.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>
Cc: James Cameron <quozl@laptop.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Eric Miao <eric.y.miao@gmail.com>,
	Haojian Zhuang <haojian.zhuang@gmail.com>,
	Daniel Mack <daniel@zonque.org>,
	Robert Jarzmik <robert.jarzmik@free.fr>,
	linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Lubomir Rintel <lkundrak@v3.sk>
Subject: [PATCH 10/11] spi: pxa2xx: Add ready signal
Date: Wed, 10 Oct 2018 19:09:35 +0200	[thread overview]
Message-ID: <20181010170936.316862-11-lkundrak@v3.sk> (raw)
In-Reply-To: <20181010170936.316862-1-lkundrak@v3.sk>

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>
---
 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 {
-- 
2.19.0


WARNING: multiple messages have this Message-ID (diff)
From: lkundrak@v3.sk (Lubomir Rintel)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 10/11] spi: pxa2xx: Add ready signal
Date: Wed, 10 Oct 2018 19:09:35 +0200	[thread overview]
Message-ID: <20181010170936.316862-11-lkundrak@v3.sk> (raw)
In-Reply-To: <20181010170936.316862-1-lkundrak@v3.sk>

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>
---
 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 {
-- 
2.19.0

  parent reply	other threads:[~2018-10-10 17:10 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10 17:09 [PATCH 0/11] spi: pxa2xx: add DT and slave mode support Lubomir Rintel
2018-10-10 17:09 ` Lubomir Rintel
2018-10-10 17:09 ` [PATCH v2 01/11] dt-bindings: spi/spi-pxa2xx: add PXA2xx SSP SPI Controller Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-10-11 14:27   ` Mark Brown
2018-10-11 14:27     ` Mark Brown
2018-10-11 17:59     ` Lubomir Rintel
2018-10-11 17:59       ` Lubomir Rintel
2018-10-12 17:00       ` Mark Brown
2018-10-12 17:00         ` Mark Brown
2018-10-17 19:32         ` Rob Herring
2018-10-17 19:32           ` Rob Herring
2018-11-04 12:00   ` Pavel Machek
2018-11-04 12:00     ` Pavel Machek
2018-10-10 17:09 ` [PATCH v2 02/11] PCI: Provide pci_match_id() with CONFIG_PCI=n Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-11-04 12:02   ` Pavel Machek
2018-11-04 12:02     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 03/11] spi: pxa2xx: Use an enum for type Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-11-04 12:03   ` Pavel Machek
2018-11-04 12:03     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 04/11] spi: pxa2xx: Add devicetree support Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-11-04 12:04   ` Pavel Machek
2018-11-04 12:04     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 05/11] DT: marvell,mmp2: Add SSP1 and SSP3 Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-10-29  5:35   ` James Cameron
2018-10-29  5:35     ` James Cameron
2018-11-04 12:06   ` Pavel Machek
2018-11-04 12:06     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 06/11] dt-bindings: spi/spi-pxa2xx: Add spi-slave property Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-10-17 19:33   ` Rob Herring
2018-10-17 19:33     ` Rob Herring
2018-11-04 12:07   ` Pavel Machek
2018-11-04 12:07     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 07/11] spi: Deal with slaves that return from transfer_one() unfinished Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-10-11  7:23   ` Geert Uytterhoeven
2018-10-11  7:23     ` Geert Uytterhoeven
2018-10-11  7:23     ` Geert Uytterhoeven
2018-11-04 12:09   ` Pavel Machek
2018-11-04 12:09     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 08/11] spi: pxa2xx: Add slave mode support Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-11-04 12:12   ` Pavel Machek
2018-11-04 12:12     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 09/11] dt-bindings: spi/spi-pxa2xx: Add ready GPIO signal Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-10-11  7:26   ` Geert Uytterhoeven
2018-10-11  7:26     ` Geert Uytterhoeven
2018-10-11  7:26     ` Geert Uytterhoeven
2018-11-04 12:13   ` Pavel Machek
2018-11-04 12:13     ` Pavel Machek
2018-10-10 17:09 ` Lubomir Rintel [this message]
2018-10-10 17:09   ` [PATCH 10/11] spi: pxa2xx: Add ready signal Lubomir Rintel
2018-10-11  7:28   ` Geert Uytterhoeven
2018-10-11  7:28     ` Geert Uytterhoeven
2018-10-11  7:28     ` Geert Uytterhoeven
2018-10-11 16:13     ` Lubomir Rintel
2018-10-11 16:13       ` Lubomir Rintel
2018-10-11 16:13       ` Lubomir Rintel
2018-11-04 12:16   ` Pavel Machek
2018-11-04 12:16     ` Pavel Machek
2018-10-10 17:09 ` [PATCH 11/11] spi: pxa2xx: Deal with the leftover garbage in TXFIFO Lubomir Rintel
2018-10-10 17:09   ` Lubomir Rintel
2018-11-04 12:19   ` Pavel Machek
2018-11-04 12:19     ` Pavel Machek

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