diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/hisilicon/reset.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/clk/hisilicon/reset.c b/drivers/clk/hisilicon/reset.c new file mode 100644 index 000000000..43e82fa64 --- /dev/null +++ b/drivers/clk/hisilicon/reset.c @@ -0,0 +1,132 @@ +/* + * Hisilicon Reset Controller Driver + * + * Copyright (c) 2015-2016 HiSilicon Technologies Co., Ltd. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/io.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 "reset.h" + +#define HISI_RESET_BIT_MASK 0x1f +#define HISI_RESET_OFFSET_SHIFT 8 +#define HISI_RESET_OFFSET_MASK 0xffff00 + +struct hisi_reset_controller { + spinlock_t lock; + void __iomem *membase; + struct reset_controller_dev rcdev; +}; + + +#define to_hisi_reset_controller(rcdev) \ + container_of(rcdev, struct hisi_reset_controller, rcdev) + +static int hisi_reset_of_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + u32 offset; + u8 bit; + + offset = (reset_spec->args[0] << HISI_RESET_OFFSET_SHIFT) + & HISI_RESET_OFFSET_MASK; + bit = reset_spec->args[1] & HISI_RESET_BIT_MASK; + + return (offset | bit); +} + +static int hisi_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct hisi_reset_controller *rstc = to_hisi_reset_controller(rcdev); + unsigned long flags; + u32 offset, reg; + u8 bit; + + offset = (id & HISI_RESET_OFFSET_MASK) >> HISI_RESET_OFFSET_SHIFT; + bit = id & HISI_RESET_BIT_MASK; + + spin_lock_irqsave(&rstc->lock, flags); + + reg = readl(rstc->membase + offset); + writel(reg | BIT(bit), rstc->membase + offset); + + spin_unlock_irqrestore(&rstc->lock, flags); + + return 0; +} + +static int hisi_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct hisi_reset_controller *rstc = to_hisi_reset_controller(rcdev); + unsigned long flags; + u32 offset, reg; + u8 bit; + + offset = (id & HISI_RESET_OFFSET_MASK) >> HISI_RESET_OFFSET_SHIFT; + bit = id & HISI_RESET_BIT_MASK; + + spin_lock_irqsave(&rstc->lock, flags); + + reg = readl(rstc->membase + offset); + writel(reg & ~BIT(bit), rstc->membase + offset); + + spin_unlock_irqrestore(&rstc->lock, flags); + + return 0; +} + +static const struct reset_control_ops hisi_reset_ops = { + .assert = hisi_reset_assert, + .deassert = hisi_reset_deassert, +}; + +struct hisi_reset_controller *hisi_reset_init(struct platform_device *pdev) +{ + struct hisi_reset_controller *rstc; + struct resource *res; + + rstc = devm_kmalloc(&pdev->dev, sizeof(*rstc), GFP_KERNEL); + if (!rstc) + return NULL; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + rstc->membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(rstc->membase)) + return NULL; + + spin_lock_init(&rstc->lock); + rstc->rcdev.owner = THIS_MODULE; + rstc->rcdev.ops = &hisi_reset_ops; + rstc->rcdev.of_node = pdev->dev.of_node; + rstc->rcdev.of_reset_n_cells = 2; + rstc->rcdev.of_xlate = hisi_reset_of_xlate; + reset_controller_register(&rstc->rcdev); + + return rstc; +} +EXPORT_SYMBOL_GPL(hisi_reset_init); + +void hisi_reset_exit(struct hisi_reset_controller *rstc) +{ + reset_controller_unregister(&rstc->rcdev); +} +EXPORT_SYMBOL_GPL(hisi_reset_exit); |