2a2b16210b
Backport upstream solution for working around SPI controller maximum message sizes. Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
42 lines
1.6 KiB
Diff
42 lines
1.6 KiB
Diff
From 3fcc36962c32ad0af2d5904103e2b2b824b6b1aa Mon Sep 17 00:00:00 2001
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From: Jonas Gorski <jonas.gorski@gmail.com>
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Date: Sat, 4 Feb 2017 12:32:59 +0100
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Subject: [PATCH 2/8] spi/bcm63xx: make spi subsystem aware of message size
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limits
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The bcm63xx LS SPI controller does not allow manual control of the CS
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lines and will toggle it automatically before after sending data, so we
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are limited to messages that fit in the FIFO buffer. Since the CS lines
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aren't available as GPIOs either, we will need to make slave drivers
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aware of this limitation and handle it accordingly.
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Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
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---
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drivers/spi/spi-bcm63xx.c | 9 +++++++++
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1 file changed, 9 insertions(+)
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--- a/drivers/spi/spi-bcm63xx.c
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+++ b/drivers/spi/spi-bcm63xx.c
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@@ -429,6 +429,13 @@ static irqreturn_t bcm63xx_spi_interrupt
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return IRQ_HANDLED;
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}
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+static size_t bcm63xx_spi_max_length(struct spi_device *spi)
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+{
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+ struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
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+
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+ return bs->fifo_size;
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+}
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+
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static const unsigned long bcm6348_spi_reg_offsets[] = {
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[SPI_CMD] = SPI_6348_CMD,
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[SPI_INT_STATUS] = SPI_6348_INT_STATUS,
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@@ -542,6 +549,8 @@ static int bcm63xx_spi_probe(struct plat
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master->transfer_one_message = bcm63xx_spi_transfer_one;
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master->mode_bits = MODEBITS;
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master->bits_per_word_mask = SPI_BPW_MASK(8);
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+ master->max_transfer_size = bcm63xx_spi_max_length;
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+ master->max_message_size = bcm63xx_spi_max_length;
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master->auto_runtime_pm = true;
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bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
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bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
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