58 lines
2.0 KiB
Diff
58 lines
2.0 KiB
Diff
From 51a164a0654895d930acb4e3bd096f7bf54c058b Mon Sep 17 00:00:00 2001
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From: Phil Elwell <phil@raspberrypi.com>
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Date: Fri, 17 Apr 2020 10:46:19 +0100
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Subject: [PATCH] spi: Force CS_HIGH if GPIO descriptors are used
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Commit f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs")
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amended of_spi_parse_dt() to always set SPI_CS_HIGH for SPI slaves whose
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Chip Select is defined by a "cs-gpios" devicetree property.
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This change breaks drivers whose probe functions set the mode field of
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the spi_device because in doing so they clear the SPI_CS_HIGH flag.
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Fix by setting SPI_CS_HIGH in spi_setup (under the same conditions as
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in of_spi_parse_dt()).
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See also: 83b2a8fe43bd ("spi: spidev: Fix CS polarity if GPIO descriptors are used")
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Fixes: f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs")
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Signed-off-by: Phil Elwell <phil@raspberrypi.com>
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SQUASH: spi: Demote SPI_CS_HIGH warning to KERN_DEBUG
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This warning is unavoidable from a client's perspective and
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doesn't indicate anything wrong (just surprising).
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SQUASH with "spi: use_gpio_descriptor fixup moved to spi_setup"
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Signed-off-by: Phil Elwell <phil@raspberrypi.com>
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---
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drivers/spi/spi.c | 9 +++++++++
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1 file changed, 9 insertions(+)
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--- a/drivers/spi/spi.c
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+++ b/drivers/spi/spi.c
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@@ -3633,6 +3633,7 @@ static int __spi_validate_bits_per_word(
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*/
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int spi_setup(struct spi_device *spi)
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{
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+ struct spi_controller *ctlr = spi->controller;
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unsigned bad_bits, ugly_bits;
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int status = 0;
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@@ -3653,6 +3654,14 @@ int spi_setup(struct spi_device *spi)
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(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
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SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
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return -EINVAL;
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+
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+ if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods &&
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+ ctlr->cs_gpiods[spi->chip_select] && !(spi->mode & SPI_CS_HIGH)) {
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+ dev_dbg(&spi->dev,
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+ "setup: forcing CS_HIGH (use_gpio_descriptors)\n");
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+ spi->mode |= SPI_CS_HIGH;
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+ }
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+
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/*
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* Help drivers fail *cleanly* when they need options
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* that aren't supported with their current controller.
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