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Diffstat (limited to 'drivers/clk/mmp/reset.c')
-rw-r--r--drivers/clk/mmp/reset.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/drivers/clk/mmp/reset.c b/drivers/clk/mmp/reset.c
new file mode 100644
index 000000000..ded7e391c
--- /dev/null
+++ b/drivers/clk/mmp/reset.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/reset-controller.h>
+
+#include "reset.h"
+
+#define rcdev_to_unit(rcdev) container_of(rcdev, struct mmp_clk_reset_unit, rcdev)
+
+static int mmp_of_reset_xlate(struct reset_controller_dev *rcdev,
+ const struct of_phandle_args *reset_spec)
+{
+ struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
+ struct mmp_clk_reset_cell *cell;
+ int i;
+
+ if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
+ return -EINVAL;
+
+ for (i = 0; i < rcdev->nr_resets; i++) {
+ cell = &unit->cells[i];
+ if (cell->clk_id == reset_spec->args[0])
+ break;
+ }
+
+ if (i == rcdev->nr_resets)
+ return -EINVAL;
+
+ return i;
+}
+
+static int mmp_clk_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
+ struct mmp_clk_reset_cell *cell;
+ unsigned long flags = 0;
+ u32 val;
+
+ cell = &unit->cells[id];
+ if (cell->lock)
+ spin_lock_irqsave(cell->lock, flags);
+
+ val = readl(cell->reg);
+ val |= cell->bits;
+ writel(val, cell->reg);
+
+ if (cell->lock)
+ spin_unlock_irqrestore(cell->lock, flags);
+
+ return 0;
+}
+
+static int mmp_clk_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
+ struct mmp_clk_reset_cell *cell;
+ unsigned long flags = 0;
+ u32 val;
+
+ cell = &unit->cells[id];
+ if (cell->lock)
+ spin_lock_irqsave(cell->lock, flags);
+
+ val = readl(cell->reg);
+ val &= ~cell->bits;
+ writel(val, cell->reg);
+
+ if (cell->lock)
+ spin_unlock_irqrestore(cell->lock, flags);
+
+ return 0;
+}
+
+static const struct reset_control_ops mmp_clk_reset_ops = {
+ .assert = mmp_clk_reset_assert,
+ .deassert = mmp_clk_reset_deassert,
+};
+
+void mmp_clk_reset_register(struct device_node *np,
+ struct mmp_clk_reset_cell *cells, int nr_resets)
+{
+ struct mmp_clk_reset_unit *unit;
+
+ unit = kzalloc(sizeof(*unit), GFP_KERNEL);
+ if (!unit)
+ return;
+
+ unit->cells = cells;
+ unit->rcdev.of_reset_n_cells = 1;
+ unit->rcdev.nr_resets = nr_resets;
+ unit->rcdev.ops = &mmp_clk_reset_ops;
+ unit->rcdev.of_node = np;
+ unit->rcdev.of_xlate = mmp_of_reset_xlate;
+
+ reset_controller_register(&unit->rcdev);
+}