Commit eedd6033 authored by Linus Walleij's avatar Linus Walleij

drm/pl111: Support variants with broken clock divider

The early Integrator CLCD synthesized in the Integrator CP and
IM-PD1 FPGAs are broken: their clock dividers do not work
properly. Support disabling the clock divider and drive the
clock directly from the parent under these circumstances.
Reviewed-by: default avatarEric Anholt <eric@anholt.net>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206093540.8147-3-linus.walleij@linaro.org
parent 6470b7dd
......@@ -138,6 +138,9 @@ static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
tim2 = readl(priv->regs + CLCD_TIM2);
tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
if (priv->variant->broken_clockdivider)
tim2 |= TIM2_BCD;
if (mode->flags & DRM_MODE_FLAG_NHSYNC)
tim2 |= TIM2_IHS;
......@@ -455,6 +458,11 @@ pl111_init_clock_divider(struct drm_device *drm)
dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
return PTR_ERR(parent);
}
/* If the clock divider is broken, use the parent directly */
if (priv->variant->broken_clockdivider) {
priv->clk = parent;
return 0;
}
parent_name = __clk_get_name(parent);
spin_lock_init(&priv->tim2_lock);
......
......@@ -38,6 +38,8 @@ struct drm_minor;
* @is_pl110: this is the early PL110 variant
* @external_bgr: this is the Versatile Pl110 variant with external
* BGR/RGB routing
* @broken_clockdivider: the clock divider is broken and we need to
* use the supplied clock directly
* @formats: array of supported pixel formats on this variant
* @nformats: the length of the array of supported pixel formats
*/
......@@ -45,6 +47,7 @@ struct pl111_variant_data {
const char *name;
bool is_pl110;
bool external_bgr;
bool broken_clockdivider;
const u32 *formats;
unsigned int nformats;
};
......
......@@ -237,6 +237,7 @@ static const u32 pl110_versatile_pixel_formats[] = {
static const struct pl111_variant_data pl110_integrator = {
.name = "PL110 Integrator",
.is_pl110 = true,
.broken_clockdivider = true,
.formats = pl110_integrator_pixel_formats,
.nformats = ARRAY_SIZE(pl110_integrator_pixel_formats),
};
......
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