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authorMingkai Hu <Mingkai.hu@freescale.com>2010-12-21 09:26:07 +0800
committerGrant Likely <grant.likely@secretlab.ca>2010-12-24 01:53:41 -0700
commite6289d63a6f39237a027dcee46366ba158cb8406 (patch)
treefb27d2b1dca5ba2a89789788a2801f427dc3b26d /drivers/spi
parent020862648445d7c1b12ea213c152f27def703f3b (diff)
downloadop-kernel-dev-e6289d63a6f39237a027dcee46366ba158cb8406.zip
op-kernel-dev-e6289d63a6f39237a027dcee46366ba158cb8406.tar.gz
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 amount 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 e3b4f64..ae78926 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);
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