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[PATCHv3,2/2] spi: dw: Set GPIO_SS flag to toggle Slave Select on GPIO CS

Message ID 1476109525-21213-2-git-send-email-tthayer@opensource.altera.com (mailing list archive)
State Accepted
Commit 80b444e57948ea4bd5a89fb1f8c404ddab6c1973
Headers show

Commit Message

tthayer@opensource.altera.com Oct. 10, 2016, 2:25 p.m. UTC
From: Thor Thayer <tthayer@opensource.altera.com>

The Designware SPI master requires slave selection before the transfer
can begin [1].

This patch uses the new master flag to indicate both the GPIO CS and
the internal chip select should be used.

Tested On:
    Altera CycloneV development kit
    Compile tested for build errors on x86_64 (allyesconfigs)

[1] DesignWare dw_apb_ssi Databook, Version 3.20a (page 39)

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
 drivers/spi/spi-dw.c |    1 +
 1 file changed, 1 insertion(+)
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diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 27960e4..b715a26 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -502,6 +502,7 @@  int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	master->handle_err = dw_spi_handle_err;
 	master->max_speed_hz = dws->max_freq;
 	master->dev.of_node = dev->of_node;
+	master->flags = SPI_MASTER_GPIO_SS;
 	/* Basic HW init */
 	spi_hw_init(dev, dws);