host->chan_rx is NULL when UNIPHIER_SD_CAP_BROKEN_DMA_RX quirk flag
is set. In this case, it should not set up DMA.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Once DMA is enabled, it is not possible to disable it because
uniphier_sd_dma_endisable() always sets the DMA_ENABLE_DMASDRW bit
regardless of the argument 'enable'. It should disable DMA when
'enable' is false.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
host->chan_{rx,tx} represents the DMA capability of the platform.
Even if DMA is supported, there are cases where we want to use PIO,
for example, data length is short enough as commit 5f52c35529
("mmc: tmio: use PIO for short transfers") mentioned.
Regarding the hardware control flow, we are interested in whether DMA
is currently enabled or not, instead of whether the platform has the
DMA capability.
Hence, the several conditionals in tmio_mmc_core.c end up with
checking host->chan_{rx,tx} and !host->force_pio. This is not nice.
Let's flip the flag host->force_pio into host->dma_on.
host->dma_on represents whether the DMA is currently enabled or not.
This flag is set false in the beginning of each command, then should
be set true by tmio_mmc_start_dma() when the DMA is turned on.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Here is another TMIO MMC variant found in Socionext UniPhier SoCs.
As commit b6147490e6 ("mmc: tmio: split core functionality, DMA and
MFD glue") said, these MMC controllers use the IP from Panasonic.
However, the MMC controller in the TMIO (Toshiba Mobile IO) MFD chip
was the first upstreamed user of this IP. The common driver code
for this IP is now called 'tmio-mmc-core' in Linux although it is a
historical misnomer.
Anyway, this driver select's MMC_TMIO_CORE to borrow the common code
from tmio-mmc-core.c
Older UniPhier SoCs (LD4, Pro4, sLD8) support the external DMA engine
like renesas_sdhi_sys_dmac.c. The difference is UniPhier SoCs use a
single DMA channel whereas Renesas chips request separate channels for
RX and TX.
Newer UniPhier SoCs (Pro5 and later) support the internal DMA engine
like renesas_sdhi_internal_dmac.c The register map is almost the same,
so I guess Renesas and Socionext use the same internal DMA hardware.
The main difference is, the register offsets are doubled for Renesas.
Renesas Socionext
SDHI UniPhier
DM_CM_DTRAN_MODE 0x820 0x410
DM_CM_DTRAN_CTRL 0x828 0x414
DM_CM_RST 0x830 0x418
DM_CM_INFO1 0x840 0x420
DM_CM_INFO1_MASK 0x848 0x424
DM_CM_INFO2 0x850 0x428
DM_CM_INFO2_MASK 0x858 0x42c
DM_DTRAN_ADDR 0x880 0x440
DM_DTRAN_ADDREX --- 0x444
This comes from the difference of host->bus_shift; 2 for Renesas SoCs,
and 1 for UniPhier SoCs. Also, the datasheet for UniPhier SoCs defines
DM_DTRAN_ADDR and DM_DTRAN_ADDREX as two separate registers.
It could be possible to factor out the DMA common code by introducing
some hooks to cope with platform quirks, but this patch does not touch
that for now.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Masahiro Yamada