/* * ZTE's zx2967 family reset controller driver * * Copyright (C) 2017 ZTE Ltd. * * Author: Baoyou Xie <baoyou.xie@linaro.org> * * License terms: GNU General Public License (GPL) version 2 */ #include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/reset-controller.h> struct zx2967_reset { void __iomem *reg_base; spinlock_t lock; struct reset_controller_dev rcdev; }; static int zx2967_reset_act(struct reset_controller_dev *rcdev, unsigned long id, bool assert) { struct zx2967_reset *reset = NULL; int bank = id / 32; int offset = id % 32; u32 reg; unsigned long flags; reset = container_of(rcdev, struct zx2967_reset, rcdev); spin_lock_irqsave(&reset->lock, flags); reg = readl_relaxed(reset->reg_base + (bank * 4)); if (assert) reg &= ~BIT(offset); else reg |= BIT(offset); writel_relaxed(reg, reset->reg_base + (bank * 4)); spin_unlock_irqrestore(&reset->lock, flags); return 0; } static int zx2967_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) { return zx2967_reset_act(rcdev, id, true); } static int zx2967_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) { return zx2967_reset_act(rcdev, id, false); } static struct reset_control_ops zx2967_reset_ops = { .assert = zx2967_reset_assert, .deassert = zx2967_reset_deassert, }; static int zx2967_reset_probe(struct platform_device *pdev) { struct zx2967_reset *reset; struct resource *res; reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL); if (!reset) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); reset->reg_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(reset->reg_base)) return PTR_ERR(reset->reg_base); spin_lock_init(&reset->lock); reset->rcdev.owner = THIS_MODULE; reset->rcdev.nr_resets = resource_size(res) * 8; reset->rcdev.ops = &zx2967_reset_ops; reset->rcdev.of_node = pdev->dev.of_node; return devm_reset_controller_register(&pdev->dev, &reset->rcdev); } static const struct of_device_id zx2967_reset_dt_ids[] = { { .compatible = "zte,zx296718-reset", }, {}, }; static struct platform_driver zx2967_reset_driver = { .probe = zx2967_reset_probe, .driver = { .name = "zx2967-reset", .of_match_table = zx2967_reset_dt_ids, }, }; builtin_platform_driver(zx2967_reset_driver);