[PATCH v16 28/40] soc/tegra: fuse: Reset hardware

Dmitry Osipenko
2021-11-30T23:25:07Z

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>
---
drivers/soc/tegra/fuse/fuse-tegra.c | 25 +++++++++++++++++++++++++
drivers/soc/tegra/fuse/fuse.h | 1 +
2 files changed, 26 insertions(+)

diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index f2151815db58..cc032729a143 100644
--- 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 de58feba0435..1b719d85bd04 100644
--- 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);
--
2.33.1