[RFC PATCH v5 6/6] drm/tidss: Enable Dual and Duplicate Modes for OLDI

Aradhya Bhatia
2022-09-28T17:53:14Z

The AM625 DSS IP contains 2 OLDI TXes which can work to enable 2
duplicated displays of smaller resolutions or enable a single Dual Link
display with a higher resolution (1920x1200).

Configure the necessary register to enable and disable the OLDI TXes
with necessary modes configurations.

Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
---
drivers/gpu/drm/tidss/tidss_dispc.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c
index 68444e0cd8d7..fd7f49535f0c 100644
--- a/drivers/gpu/drm/tidss/tidss_dispc.c
+++ b/drivers/gpu/drm/tidss/tidss_dispc.c
@@ -1003,8 +1003,8 @@ static void dispc_enable_oldi(struct dispc_device *dispc, u32 hw_videoport,
int count = 0;

/*
- * For the moment DUALMODESYNC, MASTERSLAVE, MODE, and SRC
- * bits of DISPC_VP_DSS_OLDI_CFG are set statically to 0.
+ * For the moment MASTERSLAVE, and SRC bits of DISPC_VP_DSS_OLDI_CFG are
+ * set statically to 0.
*/

if (fmt->data_width == 24)
@@ -1021,6 +1021,30 @@ static void dispc_enable_oldi(struct dispc_device *dispc, u32 hw_videoport,

oldi_cfg |= BIT(0); /* ENABLE */

+ switch (dispc->oldi_mode) {
+ case OLDI_MODE_OFF:
+ oldi_cfg &= ~BIT(0); /* DISABLE */
+ break;
+
+ case OLDI_SINGLE_LINK_SINGLE_MODE:
+ /* All configuration is done for this mode. */
+ break;
+
+ case OLDI_SINGLE_LINK_CLONE_MODE:
+ oldi_cfg |= BIT(5); /* CLONE MODE */
+ break;
+
+ case OLDI_DUAL_LINK_MODE:
+ oldi_cfg |= BIT(11); /* DUALMODESYNC */
+ oldi_cfg |= BIT(3); /* data-mapping field also indicates dual-link mode */
+ break;
+
+ default:
+ dev_warn(dispc->dev, "%s: Incorrect oldi mode. Returning.\n",
+ __func__);
+ return;
+ }
+
dispc_vp_write(dispc, hw_videoport, DISPC_VP_DSS_OLDI_CFG, oldi_cfg);

while (!(oldi_reset_bit & dispc_read(dispc, DSS_SYSSTATUS)) &&
--
2.37.0