diff options
Diffstat (limited to 'drivers/reset/reset-zx2967.c')
-rw-r--r-- | drivers/reset/reset-zx2967.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/reset/reset-zx2967.c b/drivers/reset/reset-zx2967.c new file mode 100644 index 000000000000..4dabb9ec4841 --- /dev/null +++ b/drivers/reset/reset-zx2967.c @@ -0,0 +1,99 @@ +/* + * 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); |