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https://github.com/coolsnowwolf/lede.git
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d81c03f05e
These patches were generated from: https://github.com/raspberrypi/linux/commits/rpi-6.12.y With the following command: git format-patch -N v6.12.27..HEAD (HEAD -> 8d3206ee456a5ecdf9ddbfd8e5e231e4f0cd716e) Exceptions: - (def)configs patches - github workflows patches - applied & reverted patches - readme patches - wireless patches Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
135 lines
4.4 KiB
Diff
135 lines
4.4 KiB
Diff
From 2d1edfd1b8332092022f0b5ee26c1263e63b1b8a Mon Sep 17 00:00:00 2001
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From: Nick Hollinghurst <nick.hollinghurst@raspberrypi.com>
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Date: Wed, 1 Mar 2023 17:57:11 +0000
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Subject: [PATCH] spi: gpio: Fix spi-gpio to correctly implement sck-idle-input
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Formerly, if configured using DT, CS GPIOs were driven from spi.c
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and it was possible for CS to be asserted (low) *before* starting
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to drive SCK. CS GPIOs have been brought under control of this
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driver in both ACPI and DT cases, with a fixup for GPIO polarity.
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Signed-off-by: Nick Hollinghurst <nick.hollinghurst@raspberrypi.com>
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---
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drivers/spi/spi-gpio.c | 69 +++++++++++++++++++++++++++++-------------
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1 file changed, 48 insertions(+), 21 deletions(-)
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--- a/drivers/spi/spi-gpio.c
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+++ b/drivers/spi/spi-gpio.c
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@@ -34,8 +34,9 @@ struct spi_gpio {
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struct gpio_desc *sck;
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struct gpio_desc *miso;
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struct gpio_desc *mosi;
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- bool sck_idle_input;
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struct gpio_desc **cs_gpios;
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+ bool sck_idle_input;
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+ bool cs_dont_invert;
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};
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/*----------------------------------------------------------------------*/
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@@ -232,12 +233,18 @@ static void spi_gpio_chipselect(struct s
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gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL);
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}
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- /* Drive chip select line, if we have one */
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+ /*
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+ * Drive chip select line, if we have one.
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+ * SPI chip selects are normally active-low, but when
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+ * cs_dont_invert is set, we assume their polarity is
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+ * controlled by the GPIO, and write '1' to assert.
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+ */
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if (spi_gpio->cs_gpios) {
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struct gpio_desc *cs = spi_gpio->cs_gpios[spi_get_chipselect(spi, 0)];
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+ int val = ((spi->mode & SPI_CS_HIGH) || spi_gpio->cs_dont_invert) ?
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+ is_active : !is_active;
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- /* SPI chip selects are normally active-low */
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- gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
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+ gpiod_set_value_cansleep(cs, val);
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}
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if (spi_gpio->sck_idle_input && !is_active)
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@@ -261,11 +268,14 @@ static int spi_gpio_setup(struct spi_dev
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/*
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* The CS GPIOs have already been
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* initialized from the descriptor lookup.
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+ * Here we set them to the non-asserted state.
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*/
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if (spi_gpio->cs_gpios) {
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cs = spi_gpio->cs_gpios[spi_get_chipselect(spi, 0)];
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if (!spi->controller_state && cs) {
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- ret = gpiod_direction_output(cs, !(spi->mode & SPI_CS_HIGH));
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+ ret = gpiod_direction_output(cs,
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+ !((spi->mode & SPI_CS_HIGH) ||
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+ spi_gpio->cs_dont_invert));
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if (ret)
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return ret;
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}
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@@ -342,13 +352,43 @@ static int spi_gpio_request(struct devic
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return PTR_ERR_OR_ZERO(spi_gpio->sck);
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}
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+/*
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+ * In order to implement "sck-idle-input" (which requires SCK
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+ * direction and CS level to be switched in a particular order),
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+ * we need to control GPIO chip selects from within this driver.
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+ */
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+
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+static int spi_gpio_probe_get_cs_gpios(struct device *dev,
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+ struct spi_controller *master,
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+ bool gpio_defines_polarity)
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+{
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+ int i;
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+ struct spi_gpio *spi_gpio = spi_controller_get_devdata(master);
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+
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+ spi_gpio->cs_dont_invert = gpio_defines_polarity;
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+ spi_gpio->cs_gpios = devm_kcalloc(dev, master->num_chipselect,
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+ sizeof(*spi_gpio->cs_gpios),
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+ GFP_KERNEL);
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+ if (!spi_gpio->cs_gpios)
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+ return -ENOMEM;
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+
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+ for (i = 0; i < master->num_chipselect; i++) {
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+ spi_gpio->cs_gpios[i] =
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+ devm_gpiod_get_index(dev, "cs", i,
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+ gpio_defines_polarity ?
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+ GPIOD_OUT_LOW : GPIOD_OUT_HIGH);
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+ if (IS_ERR(spi_gpio->cs_gpios[i]))
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+ return PTR_ERR(spi_gpio->cs_gpios[i]);
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+ }
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+
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+ return 0;
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+}
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+
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static int spi_gpio_probe_pdata(struct platform_device *pdev,
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struct spi_controller *host)
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{
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struct device *dev = &pdev->dev;
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struct spi_gpio_platform_data *pdata = dev_get_platdata(dev);
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- struct spi_gpio *spi_gpio = spi_controller_get_devdata(host);
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- int i;
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#ifdef GENERIC_BITBANG
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if (!pdata || !pdata->num_chipselect)
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@@ -360,20 +400,7 @@ static int spi_gpio_probe_pdata(struct p
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*/
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host->num_chipselect = pdata->num_chipselect ?: 1;
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- spi_gpio->cs_gpios = devm_kcalloc(dev, host->num_chipselect,
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- sizeof(*spi_gpio->cs_gpios),
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- GFP_KERNEL);
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- if (!spi_gpio->cs_gpios)
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- return -ENOMEM;
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-
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- for (i = 0; i < host->num_chipselect; i++) {
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- spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i,
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- GPIOD_OUT_HIGH);
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- if (IS_ERR(spi_gpio->cs_gpios[i]))
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- return PTR_ERR(spi_gpio->cs_gpios[i]);
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- }
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-
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- return 0;
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+ return spi_gpio_probe_get_cs_gpios(dev, host, false);
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}
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static int spi_gpio_probe(struct platform_device *pdev)
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