[PATCH 03/10] drm/etnaviv: add support for slave interface clock

[Lucas Stach]

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 at pengutronix.de>
---
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 13 +++++++++++++
 drivers/gpu/drm/etnaviv/etnaviv_gpu.h |  1 +
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index 4eb1a27278ec..27516f964136 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1543,6 +1543,12 @@ 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)
@@ -1581,6 +1587,8 @@ 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;
 }
@@ -1827,6 +1835,11 @@ 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 0170eb0a0923..e91200c9d4c1 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -152,6 +152,7 @@ struct etnaviv_gpu {
 
 	/* Power Control: */
 	struct clk *clk_bus;
+	struct clk *clk_reg;
 	struct clk *clk_core;
 	struct clk *clk_shader;
 
-- 
2.11.0