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path: root/drivers/clk/sunxi-ng/ccu_reset.c
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Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_reset.c')
-rw-r--r--drivers/clk/sunxi-ng/ccu_reset.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_reset.c b/drivers/clk/sunxi-ng/ccu_reset.c
new file mode 100644
index 000000000..6577aa18c
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_reset.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/reset-controller.h>
+
+#include "ccu_reset.h"
+
+static int ccu_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
+ const struct ccu_reset_map *map = &ccu->reset_map[id];
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(ccu->lock, flags);
+
+ reg = readl(ccu->base + map->reg);
+ writel(reg & ~map->bit, ccu->base + map->reg);
+
+ spin_unlock_irqrestore(ccu->lock, flags);
+
+ return 0;
+}
+
+static int ccu_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
+ const struct ccu_reset_map *map = &ccu->reset_map[id];
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(ccu->lock, flags);
+
+ reg = readl(ccu->base + map->reg);
+ writel(reg | map->bit, ccu->base + map->reg);
+
+ spin_unlock_irqrestore(ccu->lock, flags);
+
+ return 0;
+}
+
+static int ccu_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ ccu_reset_assert(rcdev, id);
+ udelay(10);
+ ccu_reset_deassert(rcdev, id);
+
+ return 0;
+}
+
+static int ccu_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
+ const struct ccu_reset_map *map = &ccu->reset_map[id];
+
+ /*
+ * The reset control API expects 0 if reset is not asserted,
+ * which is the opposite of what our hardware uses.
+ */
+ return !(map->bit & readl(ccu->base + map->reg));
+}
+
+const struct reset_control_ops ccu_reset_ops = {
+ .assert = ccu_reset_assert,
+ .deassert = ccu_reset_deassert,
+ .reset = ccu_reset_reset,
+ .status = ccu_reset_status,
+};
+EXPORT_SYMBOL_NS_GPL(ccu_reset_ops, SUNXI_CCU);