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370bf62869
There are two versions for clock reset register control for MediaTek SoCs. The old hardware is one bit per reset control, and does not have separate registers for bit set, clear and read-back operations. This matches the scheme supported by the simple reset driver. However, because we need to use different data structure from reset_simple_data, we can not use the operation of simple reset driver. For this reason, we keep the original functions and name this version as "MTK_RST_SIMPLE". In this patch: - Add a version enumeration to separate different reset hardware. - Merge the reset register function of simple and set_clr into one function "mtk_register_reset_controller". - Rename input variable "num_regs" to "rst_bank_nr" to avoid confusion. This variable is used to define the quantity of reset bank. - Document mtk_reset_version and mtk_register_reset_controller. Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20220523093346.28493-6-rex-bc.chen@mediatek.com Signed-off-by: Stephen Boyd <sboyd@kernel.org>
140 lines
3.2 KiB
C
140 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2014 MediaTek Inc.
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*/
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/slab.h>
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#include "reset.h"
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static int mtk_reset_update(struct reset_controller_dev *rcdev,
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unsigned long id, bool deassert)
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{
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struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
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unsigned int val = deassert ? 0 : ~0;
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return regmap_update_bits(data->regmap,
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data->regofs + ((id / 32) << 2),
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BIT(id % 32), val);
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}
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static int mtk_reset_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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return mtk_reset_update(rcdev, id, false);
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}
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static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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return mtk_reset_update(rcdev, id, true);
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}
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static int mtk_reset(struct reset_controller_dev *rcdev, unsigned long id)
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{
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int ret;
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ret = mtk_reset_assert(rcdev, id);
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if (ret)
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return ret;
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return mtk_reset_deassert(rcdev, id);
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}
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static int mtk_reset_update_set_clr(struct reset_controller_dev *rcdev,
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unsigned long id, bool deassert)
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{
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struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
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unsigned int deassert_ofs = deassert ? 0x4 : 0;
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return regmap_write(data->regmap,
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data->regofs + ((id / 32) << 4) + deassert_ofs,
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BIT(id % 32));
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}
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static int mtk_reset_assert_set_clr(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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return mtk_reset_update_set_clr(rcdev, id, false);
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}
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static int mtk_reset_deassert_set_clr(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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return mtk_reset_update_set_clr(rcdev, id, true);
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}
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static int mtk_reset_set_clr(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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int ret;
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ret = mtk_reset_assert_set_clr(rcdev, id);
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if (ret)
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return ret;
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return mtk_reset_deassert_set_clr(rcdev, id);
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}
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static const struct reset_control_ops mtk_reset_ops = {
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.assert = mtk_reset_assert,
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.deassert = mtk_reset_deassert,
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.reset = mtk_reset,
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};
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static const struct reset_control_ops mtk_reset_ops_set_clr = {
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.assert = mtk_reset_assert_set_clr,
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.deassert = mtk_reset_deassert_set_clr,
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.reset = mtk_reset_set_clr,
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};
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void mtk_register_reset_controller(struct device_node *np,
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u32 rst_bank_nr, u16 reg_ofs,
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enum mtk_reset_version version)
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{
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struct mtk_reset *data;
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int ret;
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struct regmap *regmap;
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const struct reset_control_ops *rcops = NULL;
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switch (version) {
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case MTK_RST_SIMPLE:
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rcops = &mtk_reset_ops;
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break;
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case MTK_RST_SET_CLR:
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rcops = &mtk_reset_ops_set_clr;
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break;
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default:
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pr_err("Unknown reset version %d\n", version);
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return;
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}
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regmap = device_node_to_regmap(np);
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if (IS_ERR(regmap)) {
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pr_err("Cannot find regmap for %pOF: %pe\n", np, regmap);
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return;
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}
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data)
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return;
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data->regmap = regmap;
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data->regofs = reg_ofs;
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data->rcdev.owner = THIS_MODULE;
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data->rcdev.nr_resets = rst_bank_nr * 32;
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data->rcdev.ops = rcops;
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data->rcdev.of_node = np;
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ret = reset_controller_register(&data->rcdev);
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if (ret) {
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pr_err("could not register reset controller: %d\n", ret);
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kfree(data);
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}
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}
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MODULE_LICENSE("GPL");
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