diff options
Diffstat (limited to 'drivers/clk/mmp/reset.c')
-rw-r--r-- | drivers/clk/mmp/reset.c | 100 |
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); +} |