dmaengine: shdma: increase size of 'dev_id'

We seem to have hit warnings of 'output may be truncated' which is fixed
by increasing the size of 'dev_id'

drivers/dma/sh/shdmac.c: In function ‘sh_dmae_probe’:
drivers/dma/sh/shdmac.c:541:34: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 9 [-Werror=format-truncation=]
541 | "sh-dmae%d.%d", pdev->id, id);
| ^~
In function ‘sh_dmae_chan_probe’,
inlined from ‘sh_dmae_probe’ at drivers/dma/sh/shdmac.c:845:9:
drivers/dma/sh/shdmac.c:541:26: note: directive argument in the range [0, 2147483647]
541 | "sh-dmae%d.%d", pdev->id, id);
| ^~~~~~~~~~~~~~
drivers/dma/sh/shdmac.c:541:26: note: directive argument in the range [0, 19]
drivers/dma/sh/shdmac.c:540:17: note: ‘snprintf’ output between 11 and 21 bytes into a destination of size 16
540 | snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
541 | "sh-dmae%d.%d", pdev->id, id);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: sh: Remove R-Mobile APE6 support

Renesas R-Mobile APE6 support is currently unused:
- DMA slaves were never enabled in r8a73a4.dtsi,
- The driver relies on legacy filter matching and describing all
slaves and MID/RIDs in a table, unlike modern DMA engine drivers for
similar hardware like rcar-dmac,
- The driver doesn't seem to work well.

Remove the driver, it can be resurrected from git history when needed.

As this was the last user of SH_DMAE_BASE on Renesas ARM SoCs, the
sh-dma-engine driver core is now used on SuperH only.

Note that the DT bindings are still present, as r8a73a4.dtsi uses them.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: use SPDX identifier for Renesas drivers

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: sh: Rework Kconfig and Makefile

Separate helpers and drivers in the Kconfig and Makefile to improve
readability and move the CONFIG_OF dependency from the Makefile to
Kconfig.

[pebolle@tiscali.nl: reported need to rename SHDMA_R8A73A4 instances]
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
[horms+renesas@verge.net.au: squashed rename of SHDMA_R8A73A4 instances]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

DMA: shdma: add r8a73a4 DMAC data to the device ID table

This configuration data will be used, when DMAC DT support is added to
r8a73a4.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

DMA: shdma: switch DT mode to use configuration data from a match table

This facilitates DMAC DT support by eliminating the need in AUXDATA and
avoiding creating complex DT data. This also fits well with DMAC devices,
of which SoCs often have multiple identical copies and it is perfectly
valid to use a single configuration data set for all of them.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

DMA: shdma: make a pointer const

Platform data shouldn't be changed at run-time, so, pointers to it should
be const.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

DMA: shdma: switch all __iomem pointers to void

In the shdma driver __iomem pointers are used to point to hardware
registers. Using typed pointers like "u32 __iomem *" in this case is
inconvenient, because then offsets, added to such pointers, have to be
devided by sizeof(u32) or similar. Switch the driver to use void
pointers, which avoids this clumsiness.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: shdma: prepare to stop using struct dma_chan::private

Using struct dma_chan::private is deprecated. To update the shdma driver to
stop using it we first have to eliminate internal runtime uses of it. After
that we will also be able to stop using it for channel configuration.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

dma: shdma: convert to the shdma base library

The shdma base library has originally been extracted from the shdma driver,
which now can be converted to actually use it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

dma: move shdma driver to an own directory

The shdma driver is going to be split into multiple files. To make this more
convenient move it to an own directory.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>