From: Alistair Francis <alistair@alistair23.me>
To: broonie@kernel.org, linux-spi@vger.kernel.org
Cc: mripard@kernel.org, wens@csie.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, alistair23@gmail.com,
Alistair Francis <alistair@alistair23.me>
Subject: [PATCH] spi: sun6i: Add support for GPIO chip select lines
Date: Tue, 5 May 2020 18:41:35 -0700 [thread overview]
Message-ID: <20200506014135.2941967-1-alistair@alistair23.me> (raw)
Add a setup function that can be used to support using generic GPIO
lines for the chip select.
Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
drivers/spi/spi-sun6i.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index ec7967be9e2f..fd4e19434942 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -10,6 +10,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -171,6 +172,31 @@ static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len)
}
}
+static int sun6i_spi_setup(struct spi_device *spi)
+{
+ int ret;
+
+ /* sanity check for native cs */
+ if (spi->mode & SPI_NO_CS)
+ return 0;
+ if (gpio_is_valid(spi->cs_gpio)) {
+ /* with gpio-cs set the GPIO to the correct level
+ * and as output (in case the dt has the gpio not configured
+ * as output but native cs)
+ */
+ ret = gpio_direction_output(spi->cs_gpio,
+ (spi->mode & SPI_CS_HIGH) ? 0 : 1);
+ if (ret)
+ dev_err(&spi->dev,
+ "could not set gpio %i as output: %i\n",
+ spi->cs_gpio, ret);
+
+ return ret;
+ }
+
+ return 0;
+}
+
static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
{
struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
@@ -470,6 +496,7 @@ static int sun6i_spi_probe(struct platform_device *pdev)
master->max_speed_hz = 100 * 1000 * 1000;
master->min_speed_hz = 3 * 1000;
+ master->setup = sun6i_spi_setup;
master->set_cs = sun6i_spi_set_cs;
master->transfer_one = sun6i_spi_transfer_one;
master->num_chipselect = 4;
--
2.26.2
next reply other threads:[~2020-05-06 1:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-06 1:41 Alistair Francis [this message]
2020-05-06 8:27 ` [PATCH] spi: sun6i: Add support for GPIO chip select lines Geert Uytterhoeven
2020-05-11 4:52 ` Alistair
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