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 v3 5/6] spi: pxa2xx: Add ready signal
Date: Tue, 13 Nov 2018 11:22:27 +0100 [thread overview]
Message-ID: <20181113102228.820214-6-lkundrak@v3.sk> (raw)
In-Reply-To: <20181113102228.820214-1-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>
Tested-by: Pavel Machek <pavel@ucw.cz>
---
Changes since v2
- Avoid an useless delay if there's no ready GPIO
- Remove useless (int)PTR_ERR(...) casts from pxa2xx_spi_probe()
(thanks to Geert Uytterhoeven)
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 54ae77f1227c..7e5aab0af501 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
next prev parent reply other threads:[~2018-11-13 10:23 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 10:22 [PATCH v3 0/6] spi: pxa2xx: add slave mode support Lubomir Rintel
2018-11-13 10:22 ` [PATCH v3 1/6] spi: pxa2xx: dt-bindings: Add spi-slave property Lubomir Rintel
2018-11-13 10:28 ` Geert Uytterhoeven
2018-11-13 10:22 ` [PATCH v3 2/6] spi: Deal with slaves that return from transfer_one() unfinished Lubomir Rintel
2018-11-13 10:33 ` Geert Uytterhoeven
2018-11-13 18:35 ` Applied "spi: Deal with slaves that return from transfer_one() unfinished" to the spi tree Mark Brown
2018-11-13 10:22 ` [PATCH v3 3/6] spi: pxa2xx: Add slave mode support Lubomir Rintel
2018-11-13 10:22 ` [PATCH v3 4/6] spi: pxa2xx: dt-bindings: Add ready GPIO signal Lubomir Rintel
2018-11-13 10:29 ` Geert Uytterhoeven
2018-11-13 18:34 ` Applied "spi: pxa2xx: dt-bindings: Add ready GPIO signal" to the spi tree Mark Brown
2018-11-13 10:22 ` Lubomir Rintel [this message]
2018-11-13 10:31 ` [PATCH v3 5/6] spi: pxa2xx: Add ready signal Geert Uytterhoeven
2018-11-13 18:34 ` Applied "spi: pxa2xx: Add ready signal" to the spi tree Mark Brown
2018-11-13 10:22 ` [PATCH v3 6/6] spi: pxa2xx: Deal with the leftover garbage in TXFIFO Lubomir Rintel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181113102228.820214-6-lkundrak@v3.sk \
--to=lkundrak@v3.sk \
--cc=broonie@kernel.org \
--cc=daniel@zonque.org \
--cc=devicetree@vger.kernel.org \
--cc=eric.y.miao@gmail.com \
--cc=geert+renesas@glider.be \
--cc=haojian.zhuang@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=quozl@laptop.org \
--cc=robert.jarzmik@free.fr \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).