diff mbox

SPI: drain MXC SPI transfer buffer when probing device

Message ID 20091119190142.GO14091@buzzloop.caiaq.de (mailing list archive)
State Accepted
Delegated to: Grant Likely
Headers show

Commit Message

Daniel Mack Nov. 19, 2009, 7:01 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index 89c22ef..1b17f44 100644
--- a/drivers/spi/spi_imx.c
+++ b/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 platform_device *pdev)
 	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);