[PATCH v4 02/11] drm/sun4i: tcon: Add support for demuxing TCON output on A31

From: Chen-Yu Tsai
Date: Mon Oct 09 2017 - 23:20:50 EST


On systems with 2 TCONs such as the A31, it is possible to demux the
output of the TCONs to one encoder.

Add support for this for the A31.

Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
---
drivers/gpu/drm/sun4i/sun4i_tcon.c | 47 ++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 75124043d655..68751b999877 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -112,6 +112,27 @@ void sun4i_tcon_enable_vblank(struct sun4i_tcon *tcon, bool enable)
}
EXPORT_SYMBOL(sun4i_tcon_enable_vblank);

+/*
+ * This function is a helper for TCON output muxing. The TCON output
+ * muxing control register in earlier SoCs (without the TCON TOP block)
+ * are located in TCON0. This helper returns a pointer to TCON0's
+ * sun4i_tcon structure, or NULL if not found.
+ */
+static struct sun4i_tcon *sun4i_get_tcon0(struct drm_device *drm)
+{
+ struct sun4i_drv *drv = drm->dev_private;
+ struct sun4i_tcon *tcon;
+
+ list_for_each_entry(tcon, &drv->tcon_list, list)
+ if (tcon->id == 0)
+ return tcon;
+
+ dev_warn(drm->dev,
+ "TCON0 not found, display output muxing may not work\n");
+
+ return NULL;
+}
+
void sun4i_tcon_set_mux(struct sun4i_tcon *tcon, int channel,
struct drm_encoder *encoder)
{
@@ -777,6 +798,31 @@ static int sun5i_a13_tcon_set_mux(struct sun4i_tcon *tcon,
return regmap_write(tcon->regs, SUN4I_TCON_MUX_CTRL_REG, val);
}

+static int sun6i_tcon_set_mux(struct sun4i_tcon *tcon,
+ struct drm_encoder *encoder)
+{
+ struct sun4i_tcon *tcon0 = sun4i_get_tcon0(encoder->dev);
+ u32 shift;
+
+ if (!tcon0)
+ return -EINVAL;
+
+ switch (encoder->encoder_type) {
+ case DRM_MODE_ENCODER_TMDS:
+ /* HDMI */
+ shift = 8;
+ break;
+ default:
+ /* TODO A31 has MIPI DSI but A31s does not */
+ return -EINVAL;
+ }
+
+ regmap_update_bits(tcon0->regs, SUN4I_TCON_MUX_CTRL_REG,
+ 0x3 << shift, tcon->id << shift);
+
+ return 0;
+}
+
static const struct sun4i_tcon_quirks sun5i_a13_quirks = {
.has_channel_1 = true,
.set_mux = sun5i_a13_tcon_set_mux,
@@ -785,6 +831,7 @@ static const struct sun4i_tcon_quirks sun5i_a13_quirks = {
static const struct sun4i_tcon_quirks sun6i_a31_quirks = {
.has_channel_1 = true,
.needs_de_be_mux = true,
+ .set_mux = sun6i_tcon_set_mux,
};

static const struct sun4i_tcon_quirks sun6i_a31s_quirks = {
--
2.14.2