The patch titled
spi: drain MXC SPI transfer buffer when probing device
has been removed from the -mm tree. Its filename was
spi-drain-mxc-spi-transfer-buffer-when-probing-device.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: spi: drain MXC SPI transfer buffer when probing device
From: Daniel Mack <daniel@xxxxxxxx>
On the MX31litekit, the bootloader seems to communicate with the MC13783
PMIC chip before booting Linux. However, it does not flush all the
buffers properly after that, which makes the imx-spi driver read bogus
data when probing the MC13783.
Fix that by draining the SPI receive buffer on startup.
Signed-off-by: Daniel Mack <daniel@xxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi_imx.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff -puN drivers/spi/spi_imx.c~spi-drain-mxc-spi-transfer-buffer-when-probing-device drivers/spi/spi_imx.c
--- a/drivers/spi/spi_imx.c~spi-drain-mxc-spi-transfer-buffer-when-probing-device
+++ a/drivers/spi/spi_imx.c
@@ -44,6 +44,9 @@
#define MXC_CSPIINT 0x0c
#define MXC_RESET 0x1c
+#define MX3_CSPISTAT 0x14
+#define MX3_CSPISTAT_RR (1 << 3)
+
/* generic defines to abstract from the different register layouts */
#define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */
#define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */
@@ -593,6 +596,11 @@ static int __init spi_imx_probe(struct p
if (!cpu_is_mx31() || !cpu_is_mx35())
writel(1, spi_imx->base + MXC_RESET);
+ /* drain receive buffer */
+ if (cpu_is_mx31() || cpu_is_mx35())
+ while (readl(spi_imx->base + MX3_CSPISTAT) & MX3_CSPISTAT_RR)
+ readl(spi_imx->base + MXC_CSPIRXDATA);
+
spi_imx->intctrl(spi_imx, 0);
ret = spi_bitbang_start(&spi_imx->bitbang);
_
Patches currently in -mm which might be from daniel@xxxxxxxx are
origin.patch
linux-next.patch
drivers-misc-add-driver-for-texas-instruments-dac7512.patch
drivers-misc-add-driver-for-texas-instruments-dac7512-update.patch
spi-imx-use-platform_driver_probe-as-probe-lives-in-inittext.patch
spi-imx-correct-check-for-platform_get_irq-failing.patch
spi-imx-use-positive-logic-to-distinguish-cpu-variants.patch
spi-imx-add-mx25-support.patch
spi-imx-dont-access-struct-device-directly-but-use-dev_get_platdata.patch
vt-make-the-default-cursor-shape-configurable.patch
drivers-video-move-dereference-after-null-test.patch
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