[Nouveau] [PATCH 1/11] ARM: tegra: add function to control the GPU rail clamp

[Vince Hsu]

The Tegra124 and later Tegra SoCs have a sepatate rail gating register
to enable/disable the clamp. The original function
tegra_powergate_remove_clamping() is not sufficient for the enable
function. So add a new function which is dedicated to the GPU rail
gating. Also don't refer to the powergate ID since the GPU ID makes no
sense here.

Signed-off-by: Vince Hsu <vinceh at nvidia.com>
---
 drivers/soc/tegra/pmc.c | 34 +++++++++++++++++++++++-----------
 include/soc/tegra/pmc.h |  2 ++
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index a2c0ceb95f8f..7798c530ead1 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -225,17 +225,6 @@ int tegra_powergate_remove_clamping(int id)
 		return -EINVAL;
 
 	/*
-	 * The Tegra124 GPU has a separate register (with different semantics)
-	 * to remove clamps.
-	 */
-	if (tegra_get_chip_id() == TEGRA124) {
-		if (id == TEGRA_POWERGATE_3D) {
-			tegra_pmc_writel(0, GPU_RG_CNTRL);
-			return 0;
-		}
-	}
-
-	/*
 	 * Tegra 2 has a bug where PCIE and VDE clamping masks are
 	 * swapped relatively to the partition ids
 	 */
@@ -253,6 +242,29 @@ int tegra_powergate_remove_clamping(int id)
 EXPORT_SYMBOL(tegra_powergate_remove_clamping);
 
 /**
+ * tegra_powergate_gpu_set_clamping - control GPU-SOC clamps
+ *
+ * The post-Tegra114 chips have a separate rail gating register to configure
+ * clamps.
+ *
+ * @assert: true to assert clamp, and false to remove
+ */
+int tegra_powergate_gpu_set_clamping(bool assert)
+{
+	if (!pmc->soc)
+		return -EINVAL;
+
+	if (tegra_get_chip_id() == TEGRA124) {
+		tegra_pmc_writel(assert ? 1 : 0, GPU_RG_CNTRL);
+		tegra_pmc_readl(GPU_RG_CNTRL);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(tegra_powergate_gpu_set_clamping);
+
+/**
  * tegra_powergate_sequence_power_up() - power up partition
  * @id: partition ID
  * @clk: clock for partition
diff --git a/include/soc/tegra/pmc.h b/include/soc/tegra/pmc.h
index 65a93273e72f..53d620525a9e 100644
--- a/include/soc/tegra/pmc.h
+++ b/include/soc/tegra/pmc.h
@@ -109,6 +109,8 @@ int tegra_powergate_is_powered(int id);
 int tegra_powergate_power_on(int id);
 int tegra_powergate_power_off(int id);
 int tegra_powergate_remove_clamping(int id);
+/* Only for Tegra124 and later */
+int tegra_powergate_gpu_set_clamping(bool assert);
 
 /* Must be called with clk disabled, and returns with clk enabled */
 int tegra_powergate_sequence_power_up(int id, struct clk *clk,
-- 
1.9.1