On 19-08-2025 12:26, Dmitry Baryshkov wrote:
On Tue, Aug 12, 2025 at 04:51:35PM +0200, Mike Looijmans wrote:
The tmds181 and sn65dp159 are "retimers" and hence can be considered
HDMI-to-HDMI bridges. Typical usage is to convert the output of an
FPGA into a valid HDMI signal, and it will typically be inserted
between an encoder and hdmi-connector.
Signed-off-by: Mike Looijmans <mike.looijm...@topic.nl>
---
drivers/gpu/drm/bridge/Kconfig | 11 +
drivers/gpu/drm/bridge/Makefile | 1 +
drivers/gpu/drm/bridge/ti-tmds181.c | 512 ++++++++++++++++++++++++++++
3 files changed, 524 insertions(+)
create mode 100644 drivers/gpu/drm/bridge/ti-tmds181.c
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index b9e0ca85226a..753177fc9b50 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -430,6 +430,17 @@ config DRM_TI_SN65DSI86
help
Texas Instruments SN65DSI86 DSI to eDP Bridge driver
+config DRM_TI_TMDS181
+ tristate "TI TMDS181 and SN65DP159 HDMI retimer bridge driver"
+ depends on OF
+ select DRM_KMS_HELPER
+ select REGMAP_I2C
+ help
+ Enable this to support the TI TMDS181 and SN65DP159 HDMI retimers.
+ The SN65DP159 provides output into a cable (source) whereas the
+ TMDS181 is meant to forward a cable signal into a PCB (sink). Either
+ can be set up as source or sink though.
+
config DRM_TI_TPD12S015
tristate "TI TPD12S015 HDMI level shifter and ESD protection"
depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 245e8a27e3fc..f4b5089e903c 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_DRM_TI_SN65DSI83) += ti-sn65dsi83.o
obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
obj-$(CONFIG_DRM_TI_TDP158) += ti-tdp158.o
obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
+obj-$(CONFIG_DRM_TI_TMDS181) += ti-tmds181.o
obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
obj-$(CONFIG_DRM_NWL_MIPI_DSI) += nwl-dsi.o
obj-$(CONFIG_DRM_ITE_IT66121) += ite-it66121.o
diff --git a/drivers/gpu/drm/bridge/ti-tmds181.c
b/drivers/gpu/drm/bridge/ti-tmds181.c
new file mode 100644
index 000000000000..6fbbc13ddc10
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ti-tmds181.c
@@ -0,0 +1,512 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI tmds181 and sn65dp159 HDMI redriver and retimer chips
+ *
+ * Copyright (C) 2018 - 2025 Topic Embedded Products <www.topic.nl>
+ *
+ * based on code
+ * Copyright (C) 2007 Hans Verkuil
+ * Copyright (C) 2016, 2017 Leon Woestenberg <l...@sidebranch.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+MODULE_DESCRIPTION("I2C device driver for DP159 and TMDS181 redriver/retimer");
+MODULE_AUTHOR("Mike Looijmans");
+MODULE_LICENSE("GPL");
+
+#define TMDS181_REG_ID 0
+#define TMDS181_REG_REV 0x8
+#define TMDS181_REG_CTRL9 0x9
+/* Registers A and B have a volatile bit, but we don't use it, so cache is ok
*/
+#define TMDS181_REG_CTRLA 0xA
+#define TMDS181_REG_CTRLB 0xB
+#define TMDS181_REG_CTRLC 0xC
+#define TMDS181_REG_EQUALIZER 0xD
+#define TMDS181_REG_EYESCAN 0xE
Usually it's recommended to use lowercase hex.
Will change in v3
...
+ /* Apply configuration changes */
+ if (of_property_read_bool(client->dev.of_node, "source-mode"))
Undocumented DT properties. Please document them in DT bindings.
Damn, this is the wrong version of the file, this looks like it's just
v1 again. I'll post v3 ASAP.
...
--
Mike Looijmans
