[PATCH v2] drm: Add Grain Media GM12U320 kms driver
Daniel Vetter
daniel at ffwll.ch
Fri Jun 3 23:19:53 UTC 2016
On Fri, Jun 03, 2016 at 07:58:57PM +0200, Hans de Goede wrote:
> Hi,
>
> Thanks for the review!
>
> On 03-06-16 19:27, Thierry Reding wrote:
> > On Fri, Jun 03, 2016 at 03:06:32PM +0200, Hans de Goede wrote:
> > > Grain-media GM12U320 based devices are mini video projectors using USB for
> > > both power and video data transport.
> > >
> > > This commit adds a kms driver for these devices, including prime support.
> > >
> > > This driver is based on the existing udl kms driver, and the gm12u320
> > > fb driver by Viacheslav Nurmekhamitov <slavrn at yandex.ru>.
> > >
> > > Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> > > ---
> > > Changes in v2:
> > > -Rebase on 4.7-rc1
> > > -Sync with udl, bring in any fixes done to udl since v1
> >
> > This sounds a little nightmarish in the long term. From a cursory look
> > this duplicates a bunch of code that's present in UDL, where the main
> > differences are EDID handling and data transfer. I wonder if we can't
> > find a better way of reusing code than duplicating it.
>
> I was planning on eventually moving the shared code to some kms-usb helper
> lib, I was thinking it would be good to have more then one user first,
> but if people prefer me first factoring out some code from udl into
> a lib I can do that instead.
Yeah I think waiting for more usb drivers is probably better. I don't want
to resurrect all the drm_bus mistakes once more, we're still working to
get rid of them all.
The other bit: Can I haz this in atomic, plz?
And when you look at atomic, it would probably be worth it to check out
Noralf's drm_simple_display_pipe helpers. They're made exactly for dumb
devices like this one here. It would cut out a lof of code.
The one thing you might need on top of Noralf's patches is some
super-simple support for cursors. That should be easy to add though.
-Daniel
>
> > > diff --git a/drivers/gpu/drm/gm12u320/gm12u320_connector.c b/drivers/gpu/drm/gm12u320/gm12u320_connector.c
> > [...]
> > > +/*
> > > + * Note this assumes this driver is only ever used with the Acer C120, if we
> > > + * add support for other devices the vendor and model should be parameterized.
> > > + */
> > > +static struct edid gm12u320_edid = {
> > > + .header = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 },
> > > + .mfg_id = { 0x04, 0x72 }, /* "ACR" */
> > > + .prod_code = { 0x20, 0xc1 }, /* C120h */
> > > + .mfg_week = 1,
> > > + .mfg_year = 1,
> > > + .version = 1, /* EDID 1.3 */
> > > + .revision = 3, /* EDID 1.3 */
> > > + .input = 0x80, /* Digital input */
> > > + .features = 0x02, /* Pref timing in DTD 1 */
> > > + .standard_timings = { { 1, 1 }, { 1, 1 }, { 1, 1 }, { 1, 1 },
> > > + { 1, 1 }, { 1, 1 }, { 1, 1 }, { 1, 1 } },
> > > + .detailed_timings = { {
> > > + .pixel_clock = 3383,
> > > + /* hactive = 852, hblank = 256 */
> > > + .data.pixel_data.hactive_lo = 0x54,
> > > + .data.pixel_data.hblank_lo = 0x00,
> > > + .data.pixel_data.hactive_hblank_hi = 0x31,
> > > + /* vactive = 480, vblank = 28 */
> > > + .data.pixel_data.vactive_lo = 0xe0,
> > > + .data.pixel_data.vblank_lo = 0x1c,
> > > + .data.pixel_data.vactive_vblank_hi = 0x10,
> > > + /* hsync offset 40 pw 128, vsync offset 1 pw 4 */
> > > + .data.pixel_data.hsync_offset_lo = 0x28,
> > > + .data.pixel_data.hsync_pulse_width_lo = 0x80,
> > > + .data.pixel_data.vsync_offset_pulse_width_lo = 0x14,
> > > + .data.pixel_data.hsync_vsync_offset_pulse_width_hi = 0x00,
> > > + /* Digital separate syncs, hsync+, vsync+ */
> > > + .data.pixel_data.misc = 0x1e,
> > > + }, {
> > > + .pixel_clock = 0,
> > > + .data.other_data.type = 0xfd, /* Monitor ranges */
> > > + .data.other_data.data.range.min_vfreq = 59,
> > > + .data.other_data.data.range.max_vfreq = 61,
> > > + .data.other_data.data.range.min_hfreq_khz = 29,
> > > + .data.other_data.data.range.max_hfreq_khz = 32,
> > > + .data.other_data.data.range.pixel_clock_mhz = 4, /* 40 MHz */
> > > + .data.other_data.data.range.flags = 0,
> > > + .data.other_data.data.range.formula.cvt = {
> > > + 0xa0, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20 },
> > > + }, {
> > > + .pixel_clock = 0,
> > > + .data.other_data.type = 0xfc, /* Model string */
> > > + .data.other_data.data.str.str = {
> > > + 'C', '1', '2', '0', 'P', 'r', 'o', 'j', 'e', 'c',
> > > + 't', 'o', 'r' },
> > > + }, {
> > > + .pixel_clock = 0,
> > > + .data.other_data.type = 0xfe, /* Unspecified text / padding */
> > > + .data.other_data.data.str.str = {
> > > + '\n', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
> > > + ' ', ' ', ' ' },
> > > + } },
> > > + .checksum = 0x40,
> > > +};
> >
> > Where did you get this from?
>
> I completely made it up, other then for the resolution which is the native
> resolution of the lcd in the projector
>
> > Doesn't this device have a chip that you can query at runtime?
>
> Not to my knowledge.
>
> > > +static int gm12u320_connector_set_property(struct drm_connector *connector,
> > > + struct drm_property *property,
> > > + uint64_t val)
> > > +{
> > > + return 0;
> > > +}
> >
> > Just drop it if it doesn't do anything.
>
> Ok, then it should probably be dropped from udl too, I'll check and submit
> a separate patch for this.
>
> > > +int gm12u320_connector_init(struct drm_device *dev,
> > > + struct drm_encoder *encoder)
> > > +{
> > > + struct drm_connector *connector;
> > > +
> > > + connector = kzalloc(sizeof(struct drm_connector), GFP_KERNEL);
> > > + if (!connector)
> > > + return -ENOMEM;
> > > +
> > > + drm_connector_init(dev, connector, &gm12u320_connector_funcs,
> > > + DRM_MODE_CONNECTOR_Unknown);
> >
> > According to the Grain Media website this chip is a USB 3.0-to-HDMI
> > bridge, so DRM_MODE_CONNECTOR_HDMIA might be a better choice here.
>
> Hmm, where did you find this ? Note I've never actually verified
> the gm12u320 name this comes from previous reverse engineering
> work done on the projector.
>
> HDMI for what is in essence a lcd panel seems wrong, maybe lvds
> if you want to avoid Unknown ?
>
> > > diff --git a/drivers/gpu/drm/gm12u320/gm12u320_drv.c b/drivers/gpu/drm/gm12u320/gm12u320_drv.c
> > [...]
> > > new file mode 100644
> > > index 0000000..eff3a44
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/gm12u320/gm12u320_drv.c
> > > @@ -0,0 +1,160 @@
> > > +/*
> > > + * Copyright (C) 2012-2016 Red Hat Inc.
> > > + *
> > > + * This file is subject to the terms and conditions of the GNU General Public
> > > + * License v2. See the file COPYING in the main directory of this archive for
> > > + * more details.
> > > + */
> > > +
> > > +#include <linux/module.h>
> > > +#include <drm/drmP.h>
> > > +#include <drm/drm_crtc_helper.h>
> > > +#include "gm12u320_drv.h"
> > > +
> > > +static int gm12u320_driver_set_busid(struct drm_device *d, struct drm_master *m)
> > > +{
> > > + return 0;
> > > +}
> >
> > This is optional, you can drop it.
>
> Idem. as above, then it should probably be dropped from udl too, I'll check and
> submit a separate patch for this.
>
> Regards,
>
> Hans
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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