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drm/panel: panel-simple: Get rid of hacky HPD chicken-and-egg code

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When I added support for the hpd-gpio to simple-panel in commit
48834e6084 ("drm/panel-simple: Support hpd-gpios for delaying
prepare()"), I added a special case to handle a circular dependency I
was running into on the ti-sn65dsi86 bridge chip. On my board the
hpd-gpio is actually provided by the bridge chip. That was causing
some circular dependency problems that I had to work around by getting
the hpd-gpio late.

I've now reorganized the ti-sn65dsi86 bridge chip driver to be a
collection of sub-drivers. Now the GPIO part can probe separately and
that breaks the chain. Let's get rid of the old code to clean things
up.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423095743.v5.10.I40eeedc23459d1e3fc96fa6cdad775d88c6e706c@changeid
This commit is contained in:
Douglas Anderson 2021-04-23 09:58:56 -07:00
parent bf73537f41
commit 5c4381eeb7
1 changed files with 5 additions and 19 deletions
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24
drivers/gpu/drm/panel/panel-simple.c
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@ -366,8 +366,7 @@ static int panel_simple_unprepare(struct drm_panel *panel)
return 0;
}
static int panel_simple_get_hpd_gpio(struct device *dev,
struct panel_simple *p, bool from_probe)
static int panel_simple_get_hpd_gpio(struct device *dev, struct panel_simple *p)
{
int err;
@ -375,17 +374,10 @@ static int panel_simple_get_hpd_gpio(struct device *dev,
if (IS_ERR(p->hpd_gpio)) {
err = PTR_ERR(p->hpd_gpio);
/*
* If we're called from probe we won't consider '-EPROBE_DEFER'
* to be an error--we'll leave the error code in "hpd_gpio".
* When we try to use it we'll try again. This allows for
* circular dependencies where the component providing the
* hpd gpio needs the panel to init before probing.
*/
if (err != -EPROBE_DEFER || !from_probe) {
if (err != -EPROBE_DEFER)
dev_err(dev, "failed to get 'hpd' GPIO: %d\n", err);
return err;
}
return err;
}
return 0;
@ -416,12 +408,6 @@ static int panel_simple_prepare_once(struct panel_simple *p)
msleep(delay);
if (p->hpd_gpio) {
if (IS_ERR(p->hpd_gpio)) {
err = panel_simple_get_hpd_gpio(dev, p, false);
if (err)
goto error;
}
if (p->desc->delay.hpd_absent_delay)
hpd_wait_us = p->desc->delay.hpd_absent_delay * 1000UL;
else
@ -682,7 +668,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
panel->no_hpd = of_property_read_bool(dev->of_node, "no-hpd");
if (!panel->no_hpd) {
err = panel_simple_get_hpd_gpio(dev, panel, true);
err = panel_simple_get_hpd_gpio(dev, panel);
if (err)
return err;
}