diff options
Diffstat (limited to 'drivers/reset/reset-sunxi.c')
-rw-r--r-- | drivers/reset/reset-sunxi.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/reset/reset-sunxi.c b/drivers/reset/reset-sunxi.c new file mode 100644 index 000000000..db9a1a755 --- /dev/null +++ b/drivers/reset/reset-sunxi.c @@ -0,0 +1,87 @@ +/* + * Allwinner SoCs Reset Controller driver + * + * Copyright 2013 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/err.h> +#include <linux/io.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include "reset-simple.h" + +static int sunxi_reset_init(struct device_node *np) +{ + struct reset_simple_data *data; + struct resource res; + resource_size_t size; + int ret; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + ret = of_address_to_resource(np, 0, &res); + if (ret) + goto err_alloc; + + size = resource_size(&res); + if (!request_mem_region(res.start, size, np->name)) { + ret = -EBUSY; + goto err_alloc; + } + + data->membase = ioremap(res.start, size); + if (!data->membase) { + ret = -ENOMEM; + goto err_alloc; + } + + spin_lock_init(&data->lock); + + data->rcdev.owner = THIS_MODULE; + data->rcdev.nr_resets = size * 8; + data->rcdev.ops = &reset_simple_ops; + data->rcdev.of_node = np; + data->active_low = true; + + return reset_controller_register(&data->rcdev); + +err_alloc: + kfree(data); + return ret; +}; + +/* + * These are the reset controller we need to initialize early on in + * our system, before we can even think of using a regular device + * driver for it. + * The controllers that we can register through the regular device + * model are handled by the simple reset driver directly. + */ +static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = { + { .compatible = "allwinner,sun6i-a31-ahb1-reset", }, + { /* sentinel */ }, +}; + +void __init sun6i_reset_init(void) +{ + struct device_node *np; + + for_each_matching_node(np, sunxi_early_reset_dt_ids) + sunxi_reset_init(np); +} |