[PATCH nouveau 06/11] platform: complete the power up/down sequence

[Vince Hsu]

This patch adds some missing pieces of the rail gaing/ungating sequence that
can improve the stability in theory.

Signed-off-by: Vince Hsu <vin...@nvidia.com>
---
 drm/nouveau_platform.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 drm/nouveau_platform.h |  3 +++
 2 files changed, 45 insertions(+)

diff --git a/drm/nouveau_platform.c b/drm/nouveau_platform.c
index 68788b17a45c..527fe2358fc9 100644
--- a/drm/nouveau_platform.c
+++ b/drm/nouveau_platform.c
@@ -25,9 +25,11 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
+#include <linux/of_platform.h>
 #include <linux/reset.h>
 #include <linux/regulator/consumer.h>
 #include <soc/tegra/fuse.h>
+#include <soc/tegra/mc.h>
 #include <soc/tegra/pmc.h>
 
 #include "nouveau_drm.h"
@@ -61,6 +63,9 @@ static int nouveau_platform_power_up(struct 
nouveau_platform_gpu *gpu)
        reset_control_deassert(gpu->rst);
        udelay(10);
 
+       tegra_mc_flush(gpu->mc, gpu->swgroup, false);
+       udelay(10);
+
        return 0;
 
 err_clamp:
@@ -77,6 +82,14 @@ static int nouveau_platform_power_down(struct 
nouveau_platform_gpu *gpu)
 {
        int err;
 
+       tegra_mc_flush(gpu->mc, gpu->swgroup, true);
+       udelay(10);
+
+       err = tegra_powergate_gpu_set_clamping(true);
+       if (err)
+               return err;
+       udelay(10);
+
        reset_control_assert(gpu->rst);
        udelay(10);
 
@@ -91,6 +104,31 @@ static int nouveau_platform_power_down(struct 
nouveau_platform_gpu *gpu)
        return 0;
 }
 
+static int nouveau_platform_get_mc(struct device *dev,
+               struct tegra_mc **mc, unsigned int *swgroup)
+{
+       struct of_phandle_args args;
+       struct platform_device *pdev;
+       int ret;
+
+       ret = of_parse_phandle_with_fixed_args(dev->of_node, "mc",
+                               1, 0, &args);
+       if (ret)
+               return ret;
+
+       pdev = of_find_device_by_node(args.np);
+       if (!pdev)
+               return -EINVAL;
+
+       *mc = platform_get_drvdata(pdev);
+       if (!*mc)
+               return -EINVAL;
+
+       *swgroup = args.args[0];
+
+       return 0;
+}
+
 static int nouveau_platform_probe(struct platform_device *pdev)
 {
        struct nouveau_platform_gpu *gpu;
@@ -118,6 +156,10 @@ static int nouveau_platform_probe(struct platform_device 
*pdev)
        if (IS_ERR(gpu->clk_pwr))
                return PTR_ERR(gpu->clk_pwr);
 
+       err = nouveau_platform_get_mc(&pdev->dev, &gpu->mc, &gpu->swgroup);
+       if (err)
+               return err;
+
        err = nouveau_platform_power_up(gpu);
        if (err)
                return err;
diff --git a/drm/nouveau_platform.h b/drm/nouveau_platform.h
index 58c28b5653d5..969dbddd786d 100644
--- a/drm/nouveau_platform.h
+++ b/drm/nouveau_platform.h
@@ -35,6 +35,9 @@ struct nouveau_platform_gpu {
        struct clk *clk_pwr;
 
        struct regulator *vdd;
+
+       struct tegra_mc *mc;
+       unsigned int swgroup;
 };
 
 struct nouveau_platform_device {
-- 
1.9.1

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