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authorMingkai Hu <Mingkai.hu@freescale.com>2010-12-01 17:29:18 +0800
committerGrant Likely <grant.likely@secretlab.ca>2010-12-29 23:04:46 -0700
commit477ca3ad6ac5cdbd5bd40941fc22c6eedc9aa90d (patch)
tree9552afcd670e798b1d98ccc4efe2f5baae572d3d /drivers/spi
parent94a544a4e8d05a027613443c529c399c39cc3371 (diff)
downloadlinux-477ca3ad6ac5cdbd5bd40941fc22c6eedc9aa90d.tar.bz2
spi/fsl_espi: change the read behaviour of the SPIRF
The user must read N bytes of SPIRF (1 <= N <= 4) that do not exceed the amount of data in the receive FIFO, so read the SPIRF byte by byte when the data in receive FIFO is less than 4 bytes. On Simics, when read N bytes that exceed the amout of data in receive FIFO, we can't read the data out, that is we can't clear the rx FIFO, then the CPU will loop on the espi rx interrupt. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi_fsl_espi.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/spi/spi_fsl_espi.c b/drivers/spi/spi_fsl_espi.c
index e3b4f6451966..ae789262c981 100644
--- a/drivers/spi/spi_fsl_espi.c
+++ b/drivers/spi/spi_fsl_espi.c
@@ -507,16 +507,29 @@ void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
/* We need handle RX first */
if (events & SPIE_NE) {
- u32 rx_data;
+ u32 rx_data, tmp;
+ u8 rx_data_8;
/* Spin until RX is done */
while (SPIE_RXCNT(events) < min(4, mspi->len)) {
cpu_relax();
events = mpc8xxx_spi_read_reg(&reg_base->event);
}
- mspi->len -= 4;
- rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
+ if (mspi->len >= 4) {
+ rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
+ } else {
+ tmp = mspi->len;
+ rx_data = 0;
+ while (tmp--) {
+ rx_data_8 = in_8((u8 *)&reg_base->receive);
+ rx_data |= (rx_data_8 << (tmp * 8));
+ }
+
+ rx_data <<= (4 - mspi->len) * 8;
+ }
+
+ mspi->len -= 4;
if (mspi->rx)
mspi->get_rx(rx_data, mspi);