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

From: Vince Hsu
Date: Tue Dec 23 2014 - 05:42:02 EST


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

Signed-off-by: Vince Hsu <vinceh@xxxxxxxxxx>
---
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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/