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authorLinus Walleij <linus.walleij@linaro.org>2011-06-16 10:14:28 +0200
committerGrant Likely <grant.likely@secretlab.ca>2011-06-16 08:26:58 -0600
commit083be3f05371b8fe0606f3abf029beeeff66d633 (patch)
tree6c4f95fb743b512381e84c239bb6ea0c9cf8b74f /drivers/spi
parente892bac102805f905e463a2cc7d0f870358cc1d5 (diff)
downloadop-kernel-dev-083be3f05371b8fe0606f3abf029beeeff66d633.zip
op-kernel-dev-083be3f05371b8fe0606f3abf029beeeff66d633.tar.gz
spi/pl022: initialize burstsize from FIFO trigger level
Configure the DMA burstsize from the FIFO trigger level supplied with the controller configuration data. This is based on a patch from Virupax, but I rewrote it differently. Reported-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-pl022.c55
1 files changed, 53 insertions, 2 deletions
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 2541705..f4b7b72 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -381,6 +381,8 @@ struct pl022 {
enum ssp_reading read;
enum ssp_writing write;
u32 exp_fifo_level;
+ enum ssp_rx_level_trig rx_lev_trig;
+ enum ssp_tx_level_trig tx_lev_trig;
/* DMA settings */
#ifdef CONFIG_DMA_ENGINE
struct dma_chan *dma_rx_channel;
@@ -907,12 +909,10 @@ static int configure_dma(struct pl022 *pl022)
struct dma_slave_config rx_conf = {
.src_addr = SSP_DR(pl022->phybase),
.direction = DMA_FROM_DEVICE,
- .src_maxburst = pl022->vendor->fifodepth >> 1,
};
struct dma_slave_config tx_conf = {
.dst_addr = SSP_DR(pl022->phybase),
.direction = DMA_TO_DEVICE,
- .dst_maxburst = pl022->vendor->fifodepth >> 1,
};
unsigned int pages;
int ret;
@@ -926,6 +926,54 @@ static int configure_dma(struct pl022 *pl022)
if (!rxchan || !txchan)
return -ENODEV;
+ /*
+ * If supplied, the DMA burstsize should equal the FIFO trigger level.
+ * Notice that the DMA engine uses one-to-one mapping. Since we can
+ * not trigger on 2 elements this needs explicit mapping rather than
+ * calculation.
+ */
+ switch (pl022->rx_lev_trig) {
+ case SSP_RX_1_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 1;
+ break;
+ case SSP_RX_4_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 4;
+ break;
+ case SSP_RX_8_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 8;
+ break;
+ case SSP_RX_16_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 16;
+ break;
+ case SSP_RX_32_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 32;
+ break;
+ default:
+ rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
+ break;
+ }
+
+ switch (pl022->tx_lev_trig) {
+ case SSP_TX_1_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 1;
+ break;
+ case SSP_TX_4_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 4;
+ break;
+ case SSP_TX_8_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 8;
+ break;
+ case SSP_TX_16_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 16;
+ break;
+ case SSP_TX_32_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 32;
+ break;
+ default:
+ tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
+ break;
+ }
+
switch (pl022->read) {
case READING_NULL:
/* Use the same as for writing */
@@ -1871,6 +1919,9 @@ static int pl022_setup(struct spi_device *spi)
goto err_config_params;
}
+ pl022->rx_lev_trig = chip_info->rx_lev_trig;
+ pl022->tx_lev_trig = chip_info->tx_lev_trig;
+
/* Now set controller state based on controller data */
chip->xfer_type = chip_info->com_mode;
if (!chip_info->cs_control) {
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