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From f61ed79b5e9e95a15a7fa1e2180dfe7d64cd2d17 Mon Sep 17 00:00:00 2001
From: Fabio Estevam <fabio.estevam@freescale.com>
Date: Mon, 23 Apr 2012 08:30:50 +0000
Subject: [PATCH 41/56] spi: mxs: Allow other chip selects to work
MXS SSP controller may have up to three chip selects per port: SS0, SS1 and SS2.
Currently only SS0 is supported in the mxs_spi driver.
Allow all the three chip select to work by selecting the desired one
in bits 20 and 21 of the HW_SSP_CTRL0 register.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
---
drivers/spi/mxs_spi.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index e7237e7..7859536 100644
--- a/drivers/spi/mxs_spi.c
+++ b/drivers/spi/mxs_spi.c
@@ -34,6 +34,8 @@
#define MXS_SPI_MAX_TIMEOUT 1000000
#define MXS_SPI_PORT_OFFSET 0x2000
+#define MXS_SSP_CHIPSELECT_MASK 0x00300000
+#define MXS_SSP_CHIPSELECT_SHIFT 20
struct mxs_spi_slave {
struct spi_slave slave;
@@ -65,6 +67,8 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
{
struct mxs_spi_slave *mxs_slave;
uint32_t addr;
+ struct mx28_ssp_regs *ssp_regs;
+ int reg;
if (!spi_cs_is_valid(bus, cs)) {
printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
@@ -82,7 +86,13 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
mxs_slave->max_khz = max_hz / 1000;
mxs_slave->mode = mode;
mxs_slave->regs = (struct mx28_ssp_regs *)addr;
+ ssp_regs = mxs_slave->regs;
+ reg = readl(&ssp_regs->hw_ssp_ctrl0);
+ reg &= ~(MXS_SSP_CHIPSELECT_MASK);
+ reg |= cs << MXS_SSP_CHIPSELECT_SHIFT;
+
+ writel(reg, &ssp_regs->hw_ssp_ctrl0);
return &mxs_slave->slave;
}
--
1.7.10
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