diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/reset/reset-socfpga.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c new file mode 100644 index 000000000..8c6492e56 --- /dev/null +++ b/drivers/reset/reset-socfpga.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018, Intel Corporation + * Copied from reset-sunxi.c + */ + +#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/reset/reset-simple.h> +#include <linux/reset/socfpga.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#define SOCFPGA_NR_BANKS 8 + +static int a10_reset_init(struct device_node *np) +{ + struct reset_simple_data *data; + struct resource res; + resource_size_t size; + int ret; + u32 reg_offset = 0x10; + + 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 release_region; + } + + if (of_property_read_u32(np, "altr,modrst-offset", ®_offset)) + pr_warn("missing altr,modrst-offset property, assuming 0x10\n"); + data->membase += reg_offset; + + spin_lock_init(&data->lock); + + data->rcdev.owner = THIS_MODULE; + data->rcdev.nr_resets = SOCFPGA_NR_BANKS * 32; + data->rcdev.ops = &reset_simple_ops; + data->rcdev.of_node = np; + data->status_active_low = true; + + ret = reset_controller_register(&data->rcdev); + if (ret) + pr_err("unable to register device\n"); + + return ret; + +release_region: + release_mem_region(res.start, size); + +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 socfpga_early_reset_dt_ids[] __initconst = { + { .compatible = "altr,rst-mgr", }, + { /* sentinel */ }, +}; + +void __init socfpga_reset_init(void) +{ + struct device_node *np; + + for_each_matching_node(np, socfpga_early_reset_dt_ids) + a10_reset_init(np); +} + +/* + * The early driver is problematic, because it doesn't register + * itself as a driver. This causes certain device links to prevent + * consumer devices from probing. The hacky solution is to register + * an empty driver, whose only job is to attach itself to the reset + * manager and call probe. + */ +static const struct of_device_id socfpga_reset_dt_ids[] = { + { .compatible = "altr,rst-mgr", }, + { /* sentinel */ }, +}; + +static int reset_simple_probe(struct platform_device *pdev) +{ + return 0; +} + +static struct platform_driver reset_socfpga_driver = { + .probe = reset_simple_probe, + .driver = { + .name = "socfpga-reset", + .of_match_table = socfpga_reset_dt_ids, + }, +}; +builtin_platform_driver(reset_socfpga_driver); |