drm/radeon/kms: add support for router objects

router objects are found on systems that use a mux to control
ddc line to connector routing or to control the actual clock and data
routing from the chip to the connectors.  This patch implements ddc line
routing.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index e71f2eb02ee2..bfd2ce5f5372 100644
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -52,6 +52,10 @@ bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
                 }
         };
 
+        /* on hw with routers, select right port */
+        if (radeon_connector->router.valid)
+                radeon_router_select_port(radeon_connector);
+
         ret = i2c_transfer(&radeon_connector->ddc_bus->adapter, msgs, 2);
         if (ret == 2)
                 return true;
@@ -1073,3 +1077,28 @@ void radeon_i2c_put_byte(struct radeon_i2c_chan *i2c_bus,
                           addr, val);
 }
 
+/* router switching */
+void radeon_router_select_port(struct radeon_connector *radeon_connector)
+{
+        u8 val;
+
+        if (!radeon_connector->router.valid)
+                return;
+
+        radeon_i2c_get_byte(radeon_connector->router_bus,
+                            radeon_connector->router.i2c_addr,
+                            0x3, &val);
+        val &= radeon_connector->router.mux_control_pin;
+        radeon_i2c_put_byte(radeon_connector->router_bus,
+                            radeon_connector->router.i2c_addr,
+                            0x3, val);
+        radeon_i2c_get_byte(radeon_connector->router_bus,
+                            radeon_connector->router.i2c_addr,
+                            0x1, &val);
+        val &= radeon_connector->router.mux_control_pin;
+        val |= radeon_connector->router.mux_state;
+        radeon_i2c_put_byte(radeon_connector->router_bus,
+                            radeon_connector->router.i2c_addr,
+                            0x1, val);
+}
+