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| author | Linus Walleij <linus.walleij@linaro.org> | 2011-06-16 10:14:28 +0200 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2011-06-16 08:26:58 -0600 |
| commit | 083be3f05371b8fe0606f3abf029beeeff66d633 (patch) | |
| tree | 6c4f95fb743b512381e84c239bb6ea0c9cf8b74f /drivers/spi/spi-pl022.c | |
| parent | e892bac102805f905e463a2cc7d0f870358cc1d5 (diff) | |
| download | lwn-083be3f05371b8fe0606f3abf029beeeff66d633.tar.gz lwn-083be3f05371b8fe0606f3abf029beeeff66d633.zip | |
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/spi-pl022.c')
| -rw-r--r-- | drivers/spi/spi-pl022.c | 55 |
1 files changed, 53 insertions, 2 deletions
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 25417054a456..f4b7b72b373e 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) { |