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https://github.com/AsahiLinux/u-boot
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89c1e2da78
A reset controller is a hardware module that controls reset signals that affect other hardware modules or chips. This patch defines a standard API that connects reset clients (i.e. the drivers for devices affected by reset signals) to drivers for reset controllers/providers. Initially, DT is the only supported method for connecting the two. The DT binding specification (reset.txt) was taken from Linux kernel v4.5's Documentation/devicetree/bindings/reset/reset.txt. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Simon Glass <sjg@chromium.org>
131 lines
2.8 KiB
C
131 lines
2.8 KiB
C
/*
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* Copyright (c) 2016, NVIDIA CORPORATION.
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*
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* SPDX-License-Identifier: GPL-2.0
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*/
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#include <common.h>
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#include <dm.h>
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#include <fdtdec.h>
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#include <reset.h>
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#include <reset-uclass.h>
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DECLARE_GLOBAL_DATA_PTR;
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static inline struct reset_ops *reset_dev_ops(struct udevice *dev)
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{
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return (struct reset_ops *)dev->driver->ops;
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}
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static int reset_of_xlate_default(struct reset_ctl *reset_ctl,
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struct fdtdec_phandle_args *args)
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{
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debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
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if (args->args_count != 1) {
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debug("Invaild args_count: %d\n", args->args_count);
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return -EINVAL;
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}
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reset_ctl->id = args->args[0];
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return 0;
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}
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int reset_get_by_index(struct udevice *dev, int index,
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struct reset_ctl *reset_ctl)
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{
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struct fdtdec_phandle_args args;
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int ret;
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struct udevice *dev_reset;
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struct reset_ops *ops;
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debug("%s(dev=%p, index=%d, reset_ctl=%p)\n", __func__, dev, index,
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reset_ctl);
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ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
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"resets", "#reset-cells", 0,
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index, &args);
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if (ret) {
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debug("%s: fdtdec_parse_phandle_with_args failed: %d\n",
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__func__, ret);
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return ret;
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}
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ret = uclass_get_device_by_of_offset(UCLASS_RESET, args.node,
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&dev_reset);
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if (ret) {
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debug("%s: uclass_get_device_by_of_offset failed: %d\n",
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__func__, ret);
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return ret;
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}
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ops = reset_dev_ops(dev_reset);
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reset_ctl->dev = dev_reset;
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if (ops->of_xlate)
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ret = ops->of_xlate(reset_ctl, &args);
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else
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ret = reset_of_xlate_default(reset_ctl, &args);
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if (ret) {
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debug("of_xlate() failed: %d\n", ret);
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return ret;
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}
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ret = ops->request(reset_ctl);
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if (ret) {
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debug("ops->request() failed: %d\n", ret);
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return ret;
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}
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return 0;
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}
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int reset_get_by_name(struct udevice *dev, const char *name,
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struct reset_ctl *reset_ctl)
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{
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int index;
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debug("%s(dev=%p, name=%s, reset_ctl=%p)\n", __func__, dev, name,
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reset_ctl);
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index = fdt_find_string(gd->fdt_blob, dev->of_offset, "reset-names",
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name);
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if (index < 0) {
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debug("fdt_find_string() failed: %d\n", index);
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return index;
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}
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return reset_get_by_index(dev, index, reset_ctl);
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}
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int reset_free(struct reset_ctl *reset_ctl)
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{
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struct reset_ops *ops = reset_dev_ops(reset_ctl->dev);
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debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
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return ops->free(reset_ctl);
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}
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int reset_assert(struct reset_ctl *reset_ctl)
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{
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struct reset_ops *ops = reset_dev_ops(reset_ctl->dev);
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debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
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return ops->rst_assert(reset_ctl);
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}
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int reset_deassert(struct reset_ctl *reset_ctl)
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{
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struct reset_ops *ops = reset_dev_ops(reset_ctl->dev);
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debug("%s(reset_ctl=%p)\n", __func__, reset_ctl);
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return ops->rst_deassert(reset_ctl);
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}
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UCLASS_DRIVER(reset) = {
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.id = UCLASS_RESET,
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.name = "reset",
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};
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