diff options
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_reset.c')
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_reset.c | 81 |
1 files changed, 81 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..b67149143 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_reset.c @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2016 Maxime Ripard + * Maxime Ripard <maxime.ripard@free-electrons.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + */ + +#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, +}; |