diff options
Diffstat (limited to 'drivers/reset/reset-ath79.c')
-rw-r--r-- | drivers/reset/reset-ath79.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/reset/reset-ath79.c b/drivers/reset/reset-ath79.c new file mode 100644 index 000000000000..d2d290413113 --- /dev/null +++ b/drivers/reset/reset-ath79.c @@ -0,0 +1,128 @@ +/* + * Copyright (C) 2015 Alban Bedel <albeu@free.fr> + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> + +struct ath79_reset { + struct reset_controller_dev rcdev; + void __iomem *base; + spinlock_t lock; +}; + +static int ath79_reset_update(struct reset_controller_dev *rcdev, + unsigned long id, bool assert) +{ + struct ath79_reset *ath79_reset = + container_of(rcdev, struct ath79_reset, rcdev); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&ath79_reset->lock, flags); + val = readl(ath79_reset->base); + if (assert) + val |= BIT(id); + else + val &= ~BIT(id); + writel(val, ath79_reset->base); + spin_unlock_irqrestore(&ath79_reset->lock, flags); + + return 0; +} + +static int ath79_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return ath79_reset_update(rcdev, id, true); +} + +static int ath79_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return ath79_reset_update(rcdev, id, false); +} + +static int ath79_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ath79_reset *ath79_reset = + container_of(rcdev, struct ath79_reset, rcdev); + u32 val; + + val = readl(ath79_reset->base); + + return !!(val & BIT(id)); +} + +static struct reset_control_ops ath79_reset_ops = { + .assert = ath79_reset_assert, + .deassert = ath79_reset_deassert, + .status = ath79_reset_status, +}; + +static int ath79_reset_probe(struct platform_device *pdev) +{ + struct ath79_reset *ath79_reset; + struct resource *res; + + ath79_reset = devm_kzalloc(&pdev->dev, + sizeof(*ath79_reset), GFP_KERNEL); + if (!ath79_reset) + return -ENOMEM; + + platform_set_drvdata(pdev, ath79_reset); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ath79_reset->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(ath79_reset->base)) + return PTR_ERR(ath79_reset->base); + + ath79_reset->rcdev.ops = &ath79_reset_ops; + ath79_reset->rcdev.owner = THIS_MODULE; + ath79_reset->rcdev.of_node = pdev->dev.of_node; + ath79_reset->rcdev.of_reset_n_cells = 1; + ath79_reset->rcdev.nr_resets = 32; + + return reset_controller_register(&ath79_reset->rcdev); +} + +static int ath79_reset_remove(struct platform_device *pdev) +{ + struct ath79_reset *ath79_reset = platform_get_drvdata(pdev); + + reset_controller_unregister(&ath79_reset->rcdev); + + return 0; +} + +static const struct of_device_id ath79_reset_dt_ids[] = { + { .compatible = "qca,ar7100-reset", }, + { }, +}; +MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids); + +static struct platform_driver ath79_reset_driver = { + .probe = ath79_reset_probe, + .remove = ath79_reset_remove, + .driver = { + .name = "ath79-reset", + .of_match_table = ath79_reset_dt_ids, + }, +}; +module_platform_driver(ath79_reset_driver); + +MODULE_AUTHOR("Alban Bedel <albeu@free.fr>"); +MODULE_DESCRIPTION("AR71xx Reset Controller Driver"); +MODULE_LICENSE("GPL"); |