Commit graph

13 commits

Author SHA1 Message Date
Andy Shevchenko
ec03c21043 staging: fbtft: Rectify GPIO handling
The infamous commit c440eee1a7 ("Staging: staging: fbtft: Switch to
the GPIO descriptor interface") broke GPIO handling completely.
It has already four commits to rectify and it seems not enough.
In order to fix the mess here we:

  1) Set default to "inactive" for all requested pins

  2) Fix CS#, RD#, and WR# pins polarity since it's active low
     and GPIO descriptor interface takes it into consideration
     from the Device Tree or ACPI

  3) Consolidate chip activation (CS# assertion) under default
     ->reset() callback

To summarize the expectations about polarity for GPIOs:

   RD#			Low
   WR#			Low
   CS#			Low
   RESET#		Low
   DC or RS		High
   RW			High
   Data	0 .. 15		High

See also Adafruit learning course [1] for the example of the schematics.

While at it, drop unneeded NULL checks, since GPIO API is tolerant to that.

[1]: https://learn.adafruit.com/adafruit-2-8-and-3-2-color-tft-touchscreen-breakout-v2/downloads

Fixes: 92e3e88488 ("Staging: fbtft: Fix GPIO handling")
Fixes: b918d1c270 ("Staging: fbtft: Fix reset assertion when using gpio descriptor")
Fixes: dbc4f989c8 ("Staging: fbtft: Fix probing of gpio descriptor")
Fixes: c440eee1a7 ("Staging: fbtft: Switch to the gpio descriptor interface")
Cc: Jan Sebastian Götte <linux@jaseg.net>
Cc: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210503172114.27891-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-10 11:19:39 +02:00
Nishad Kamdar
c440eee1a7 Staging: fbtft: Switch to the gpio descriptor interface
This switches the fbtft driver to use GPIO descriptors
rather than numerical gpios:

Utilize the GPIO library's intrinsic handling of OF GPIOs
and polarity. If the line is flagged active low, gpiolib
will deal with this.

Remove gpios from platform device structure. Neither assign
statically numbers to gpios in platform device nor allow
gpios to be parsed as module parameters.

Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18 11:01:02 +01:00
Greg Kroah-Hartman
78c00ccc52 staging: fbtft: remove redundant license text
Now that the SPDX tag is in all fbtft files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-15 16:03:46 +01:00
Greg Kroah-Hartman
783de57c52 staging: fbtft: add SPDX identifiers
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Fix up the all of the staging fbtft drivers to have a proper SPDX
identifier, based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-15 16:03:46 +01:00
Eva Rachel Retuya
f07e89ce1e staging: fbtft: Fix alignment to match open parenthesis
Fix alignment issues by properly indenting function parameters in
accordance to the kernel coding style. Checkpatch pointed out this
issue.

CHECK: Alignment should match open parenthesis

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-14 16:22:49 -08:00
Priit Laes
261a984c88 staging: fbtft: Use standard MIPI DCS command defines for ili9340
This patch makes use of the standard MIPI Display Command Set to remove
some of the magic constants found in source code.

Signed-off-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 19:39:27 -08:00
Shraddha Barke
64ffdc383b Staging: fbtft: Remove debug messages
Remove debug messages related to fbtft_par_dbg(DEBUG_INIT_DISPLAY.. )
as this info can be obtained using kernel function tracer

Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21 09:56:50 -07:00
Anish Bhatt
1014c2ce08 staging/fbtft : Fix multiple/missing blank line issues
Remove or add blank lines as recommended by checkpatch.pl

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-12 18:24:36 -07:00
Anish Bhatt
e73221877a staging/fbtft : Remove repeated set_addr_win debug messages
fbtft_par_dbg(DEBUG_SET_ADDR_WIN.. ) is repeated in every
set_addr_win() handler, this could be replicated by using the kernel
function tracer instead.

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-12 18:24:36 -07:00
Anish Bhatt
4a1a838362 staging/fbtft : Remove FSF mailing address
checkpatch.pl recommends that this is no longer required.
Also replaces ASCII-art copyright notice with simple text

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-12 18:24:35 -07:00
Masanari Iida
92def781ee staging: fbtft: Fix typo in fbtft
This patch fix spelling typo in comment and printk within fbtft

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 13:07:29 +01:00
Aya Mahfouz
43da0d92ab staging: fbtft: fix space prohibited before that ','
This patch fixes the following checkpatch.pl error:
space prohibited before that ','

Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-24 15:31:15 -08:00
Thomas Petazzoni
8f7fdaafff staging: fbtft: add fb_ili9340 driver
This commit adds the fb_ili9340 driver from the fbtft project at
https://github.com/notro/fbtft.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Noralf Tronnes <notro@tronnes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-17 16:46:46 -08:00