linux-toradex.git/include/drm/tinydrm, branch master

drm/tinydrm: Move mipi-dbi

2019-07-25T08:45:07+00:00

This moves mipi-dbi to be a core helper with the name drm_mipi_dbi.

Fixup include's in drivers.
Move the docs entry and delete tinydrm.rst.
Delete the last tinydrm todo entry.

v2: Make DRM_MIPI_DBI tristate to enable it being built as a module.

Cc: Eric Anholt 
Cc: David Lechner 
Reviewed-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Acked-by: David Lechner 
Acked-by: Eric Anholt 
Link: https://patchwork.freedesktop.org/patch/msgid/20190722104312.16184-9-noralf@tronnes.org

drm/tinydrm: Split struct mipi_dbi in two

2019-07-25T08:42:25+00:00

Split struct mipi_dbi into an interface part and a display pipeline part.
The interface part can be used by drivers that need to initialize the
controller, but that won't upload the framebuffer over this interface.

MIPI DBI supports 3 interface types:
- A. Motorola 6800 type parallel bus
- B. Intel 8080 type parallel bus
- C. SPI type with 3 options:

I've embedded the SPI type specifics in the mipi_dbi struct to avoid
adding unnecessary complexity. If more interface types will be supported
in the future, the type specifics might have to be split out.

Rename functions to match the new struct mipi_dbi_dev:
- drm_to_mipi_dbi() -> drm_to_mipi_dbi_dev().
- mipi_dbi_init*() -> mipi_dbi_dev_init*().

Cc: Eric Anholt 
Cc: David Lechner 
Reviewed-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Acked-by: David Lechner 
Acked-by: Eric Anholt 
Link: https://patchwork.freedesktop.org/patch/msgid/20190722104312.16184-5-noralf@tronnes.org

drm/tinydrm: Rename remaining variable mipi -> dbidev

2019-07-25T08:41:10+00:00

struct mipi_dbi is going to be split into an interface part and a display
pipeline part. The interface part can be used by drivers that need to
initialize the controller, but that won't upload the framebuffer over
this interface.

tinydrm uses the variable name 'mipi' but this is not a good name since
MIPI refers to a lot of standards. This patch changes the variable name
to 'dbidev' where it refers to the pipeline part of struct mipi_dbi.

Cc: Eric Anholt 
Cc: David Lechner 
Reviewed-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Acked-by: David Lechner 
Acked-by: Eric Anholt 
Link: https://patchwork.freedesktop.org/patch/msgid/20190722104312.16184-4-noralf@tronnes.org

drm/tinydrm: Rename variable mipi -> dbi

2019-07-25T08:40:01+00:00

struct mipi_dbi is going to be split into an interface part and a display
pipeline part. The interface part can be used by drivers that need to
initialize the controller, but that won't upload the framebuffer over
this interface.

tinydrm uses the variable name 'mipi' but this is not a good name since
MIPI refers to a lot of standards. This patch changes the variable name
to 'dbi' where it refers to the interface part of struct mipi_dbi.

Functions that use both future parts will have both variables temporarily
pointing to the same structure.

Cc: Eric Anholt 
Cc: David Lechner 
Reviewed-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Acked-by: David Lechner 
Acked-by: Eric Anholt 
Link: https://patchwork.freedesktop.org/patch/msgid/20190722104312.16184-3-noralf@tronnes.org

drm/tinydrm: Move tinydrm_display_pipe_init() to mipi-dbi

2019-07-23T13:50:46+00:00

tinydrm_display_pipe_init() has only one user now, so move it to mipi-dbi.

Changes:
- Remove drm_connector_helper_funcs.detect, it's always connected.
- Store the connector and mode in mipi_dbi instead of it's own struct.

Otherwise remove some leftover tinydrm-helpers.h inclusions.

Cc: Eric Anholt 
Cc: David Lechner 
Reviewed-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-12-noralf@tronnes.org

drm/tinydrm/mipi-dbi: Add mipi_dbi_init_with_formats()

2019-07-23T13:49:39+00:00

The MIPI DBI standard support more pixel formats than what this helper
supports. Add an init function that lets the driver use different
format(s). This avoids open coding mipi_dbi_init() in st7586.

st7586 sets preferred_depth but this is not necessary since it only
supports one format.

v2: Forgot to remove the mipi->rotation assignment in st7586,
    mipi_dbi_init_with_formats() handles it.

Cc: David Lechner 
Acked-by: David Lechner 
Signed-off-by: Noralf Trønnes 
Tested-by: David Lechner 
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-11-noralf@tronnes.org

drm/tinydrm: Move tinydrm_machine_little_endian()

2019-07-23T13:47:58+00:00

The tinydrm helper is going away so move it into the only user mipi-dbi.

Reviewed-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-9-noralf@tronnes.org

drm/tinydrm: Move tinydrm_spi_transfer()

2019-07-23T13:47:33+00:00

This is only used by mipi-dbi drivers so move it there.

The reason this isn't moved to the SPI subsystem is that it will in a
later patch pass a dummy rx buffer for SPI controllers that need this.
Low memory boards (64MB) can run into a problem allocating such a "large"
contiguous buffer on every transfer after a long up time.
This leaves a very specific use case, so we'll keep the function here.
mipi-dbi will first go through a refactoring though, before this will
be done.

Remove SPI todo entry now that we're done with the tinydrm.ko SPI code.

v2: Drop moving the mipi_dbi_spi_init() declaration (Sam)

Cc: David Lechner 
Reviewed-by: Sam Ravnborg 
Acked-by: : David Lechner 
Signed-off-by: Noralf Trønnes 
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-8-noralf@tronnes.org

drm/tinydrm: Clean up tinydrm_spi_transfer()

2019-07-23T13:46:56+00:00

Prep work before moving the function to mipi-dbi.

tinydrm_spi_transfer() was made to support one class of drivers in
drivers/staging/fbtft that has not been converted to DRM yet, so strip
away the unused functionality:
- Start byte (header) is not used.
- No driver relies on the automatic 16-bit byte swapping on little endian
  machines with SPI controllers only supporting 8 bits per word.

Other changes:
- No need to initialize ret
- No need for the WARN since mipi-dbi only uses 8 and 16 bpw.
- Use spi_message_init_with_transfers()

Cc: David Lechner 
Acked-by: : David Lechner 
Signed-off-by: Noralf Trønnes 
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-7-noralf@tronnes.org

drm/tinydrm: Remove tinydrm_spi_max_transfer_size()

2019-07-23T13:46:27+00:00

spi-bcm2835 can handle >64kB buffers now so there is no need to check
->max_dma_len. The tinydrm_spi_max_transfer_size() max_len argument is
not used by any callers, so not needed.

Then we have the spi_max module parameter. It was added because
staging/fbtft has support for it and there was a report that someone used
it to set a small buffer size to avoid popping on a USB soundcard on a
Raspberry Pi. In hindsight it shouldn't have been added, I should have
waited for it to become a problem first. I don't know it anyone is
actually using it, but since tinydrm_spi_transfer() is being moved to
mipi-dbi, I'm taking the opportunity to remove it. I'll add it back to
mipi-dbi if someone complains.

With that out of the way, spi_max_transfer_size() can be used instead.

The chosen 16kB buffer size for Type C Option 1 (9-bit) interface is
somewhat arbitrary, but a bigger buffer will have a miniscule impact on
transfer speed, so it's probably fine.

Acked-by: Sam Ravnborg 
Signed-off-by: Noralf Trønnes 
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-6-noralf@tronnes.org