91 lines
3 KiB
Diff
91 lines
3 KiB
Diff
From d1d81802522ade84128a2c66c0d500e372474dca Mon Sep 17 00:00:00 2001
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From: Torsten Fleischer <torfl6749@gmail.com>
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Date: Mon, 3 Nov 2014 17:17:55 +0100
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Subject: [PATCH] spi: spi-gpio: Add dt support for a single device with no
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chip select
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In order to describe a single slave device that has no chip select line
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the 'num-chipselects' property has to be <0> and the 'cs-gpios' property
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doesn't need to be set.
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Signed-off-by: Torsten Fleischer <torfl6749@gmail.com>
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Signed-off-by: Mark Brown <broonie@kernel.org>
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---
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Documentation/devicetree/bindings/spi/spi-gpio.txt | 6 ++++--
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drivers/spi/spi-gpio.c | 21 +++++++++++++++------
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2 files changed, 19 insertions(+), 8 deletions(-)
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--- a/Documentation/devicetree/bindings/spi/spi-gpio.txt
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+++ b/Documentation/devicetree/bindings/spi/spi-gpio.txt
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@@ -8,8 +8,10 @@ Required properties:
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- gpio-sck: GPIO spec for the SCK line to use
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- gpio-miso: GPIO spec for the MISO line to use
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- gpio-mosi: GPIO spec for the MOSI line to use
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- - cs-gpios: GPIOs to use for chipselect lines
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- - num-chipselects: number of chipselect lines
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+ - cs-gpios: GPIOs to use for chipselect lines.
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+ Not needed if num-chipselects = <0>.
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+ - num-chipselects: Number of chipselect lines. Should be <0> if a single device
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+ with no chip select is connected.
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Example:
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--- a/drivers/spi/spi-gpio.c
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+++ b/drivers/spi/spi-gpio.c
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@@ -425,6 +425,7 @@ static int spi_gpio_probe(struct platfor
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struct spi_gpio_platform_data *pdata;
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u16 master_flags = 0;
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bool use_of = 0;
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+ int num_devices;
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status = spi_gpio_probe_dt(pdev);
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if (status < 0)
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@@ -434,16 +435,21 @@ static int spi_gpio_probe(struct platfor
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pdata = dev_get_platdata(&pdev->dev);
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#ifdef GENERIC_BITBANG
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- if (!pdata || !pdata->num_chipselect)
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+ if (!pdata || (!use_of && !pdata->num_chipselect))
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return -ENODEV;
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#endif
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+ if (use_of && !SPI_N_CHIPSEL)
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+ num_devices = 1;
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+ else
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+ num_devices = SPI_N_CHIPSEL;
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+
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status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags);
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if (status < 0)
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return status;
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master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) +
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- (sizeof(int) * SPI_N_CHIPSEL));
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+ (sizeof(int) * num_devices));
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if (!master) {
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status = -ENOMEM;
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goto gpio_free;
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@@ -458,7 +464,7 @@ static int spi_gpio_probe(struct platfor
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master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
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master->flags = master_flags;
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master->bus_num = pdev->id;
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- master->num_chipselect = SPI_N_CHIPSEL;
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+ master->num_chipselect = num_devices;
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master->setup = spi_gpio_setup;
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master->cleanup = spi_gpio_cleanup;
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#ifdef CONFIG_OF
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@@ -473,9 +479,12 @@ static int spi_gpio_probe(struct platfor
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* property of the node.
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*/
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- for (i = 0; i < SPI_N_CHIPSEL; i++)
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- spi_gpio->cs_gpios[i] =
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- of_get_named_gpio(np, "cs-gpios", i);
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+ if (!SPI_N_CHIPSEL)
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+ spi_gpio->cs_gpios[0] = SPI_GPIO_NO_CHIPSELECT;
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+ else
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+ for (i = 0; i < SPI_N_CHIPSEL; i++)
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+ spi_gpio->cs_gpios[i] =
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+ of_get_named_gpio(np, "cs-gpios", i);
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}
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#endif
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