soc/tegra: fuse: Reset hardware

The FUSE controller is enabled at a boot time. Reset it in order to put
hardware and clock into clean and disabled state.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index f215181..cc03272 100644 (file)
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -14,6 +14,7 @@
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/sys_soc.h>
 
@@ -243,6 +244,30 @@ static int tegra_fuse_probe(struct platform_device *pdev)
                goto restore;
        }
 
+       fuse->rst = devm_reset_control_get_optional(&pdev->dev, "fuse");
+       if (IS_ERR(fuse->rst)) {
+               err = PTR_ERR(fuse->rst);
+               dev_err(&pdev->dev, "failed to get FUSE reset: %pe\n",
+                       fuse->rst);
+               goto restore;
+       }
+
+       /*
+        * FUSE clock is enabled at a boot time, hence this resume/suspend
+        * disables the clock besides the h/w resetting.
+        */
+       err = pm_runtime_resume_and_get(&pdev->dev);
+       if (err)
+               goto restore;
+
+       err = reset_control_reset(fuse->rst);
+       pm_runtime_put(&pdev->dev);
+
+       if (err < 0) {
+               dev_err(&pdev->dev, "failed to reset FUSE: %d\n", err);
+               goto restore;
+       }
+
        /* release the early I/O memory mapping */
        iounmap(base);
 

diff --git a/drivers/soc/tegra/fuse/fuse.h b/drivers/soc/tegra/fuse/fuse.h
index de58feb..1b719d8 100644 (file)
--- a/drivers/soc/tegra/fuse/fuse.h
+++ b/drivers/soc/tegra/fuse/fuse.h
@@ -43,6 +43,7 @@ struct tegra_fuse {
        void __iomem *base;
        phys_addr_t phys;
        struct clk *clk;
+       struct reset_control *rst;
 
        u32 (*read_early)(struct tegra_fuse *fuse, unsigned int offset);
        u32 (*read)(struct tegra_fuse *fuse, unsigned int offset);