drm/etnaviv: add support for slave interface clock

The slave interface clock is a clock input found on newer cores to gate
the register interface. For now we simply ungate it when the GPU is in
active state.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index ee24861..260a73a 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1383,6 +1383,12 @@ static int etnaviv_gpu_clk_enable(struct etnaviv_gpu *gpu)
 {
        int ret;
 
+       if (gpu->clk_reg) {
+               ret = clk_prepare_enable(gpu->clk_reg);
+               if (ret)
+                       return ret;
+       }
+
        if (gpu->clk_bus) {
                ret = clk_prepare_enable(gpu->clk_bus);
                if (ret)
@@ -1421,6 +1427,8 @@ static int etnaviv_gpu_clk_disable(struct etnaviv_gpu *gpu)
                clk_disable_unprepare(gpu->clk_core);
        if (gpu->clk_bus)
                clk_disable_unprepare(gpu->clk_bus);
+       if (gpu->clk_reg)
+               clk_disable_unprepare(gpu->clk_reg);
 
        return 0;
 }
@@ -1676,6 +1684,11 @@ static int etnaviv_gpu_platform_probe(struct platform_device *pdev)
        }
 
        /* Get Clocks: */
+       gpu->clk_reg = devm_clk_get(&pdev->dev, "reg");
+       DBG("clk_reg: %p", gpu->clk_reg);
+       if (IS_ERR(gpu->clk_reg))
+               gpu->clk_reg = NULL;
+
        gpu->clk_bus = devm_clk_get(&pdev->dev, "bus");
        DBG("clk_bus: %p", gpu->clk_bus);
        if (IS_ERR(gpu->clk_bus))

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
index 186f7c7..3b19528 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -147,6 +147,7 @@ struct etnaviv_gpu {
 
        /* Power Control: */
        struct clk *clk_bus;
+       struct clk *clk_reg;
        struct clk *clk_core;
        struct clk *clk_shader;