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spi: pxa2xx: use DMA by default if supported

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Currently, even if the PXA2xx SPI master supports DMA, it won't be
enabled unless (i) the slave device is enumerated through ACPI, or
(ii) the slave device is registered with board-specific
controller_data specified.  Even then, there isn't a field in the
controller_data that explicitly enables dma - it just gets enabled
if the master supports it and controller_data is non-NULL.

This means that drivers which register SPI devices on a bus without
awareness of this controller cannot avail of DMA performance gains.

This patch allows DMA transfers to be used if supported.

Signed-off-by: Dan O'Donovan <dan@emutex.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Dan O'Donovan 2016-05-27 19:57:48 +01:00 committed by Mark Brown
parent 1a695a905c
commit c64e1265ae
1 changed files with 1 additions and 9 deletions
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10
drivers/spi/spi-pxa2xx.c
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@ -1240,7 +1240,7 @@ static int setup(struct spi_device *spi)
chip->frm = spi->chip_select;
} else
chip->gpio_cs = -1;
chip->enable_dma = 0;
chip->enable_dma = drv_data->master_info->enable_dma;
chip->timeout = TIMOUT_DFLT;
}
@ -1259,17 +1259,9 @@ static int setup(struct spi_device *spi)
tx_hi_thres = chip_info->tx_hi_threshold;
if (chip_info->rx_threshold)
rx_thres = chip_info->rx_threshold;
chip->enable_dma = drv_data->master_info->enable_dma;
chip->dma_threshold = 0;
if (chip_info->enable_loopback)
chip->cr1 = SSCR1_LBM;
} else if (ACPI_HANDLE(&spi->dev)) {
/*
* Slave devices enumerated from ACPI namespace don't
* usually have chip_info but we still might want to use
* DMA with them.
*/
chip->enable_dma = drv_data->master_info->enable_dma;
}
chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);