diff options
Diffstat (limited to 'drivers/clk/mediatek/reset.c')
| -rw-r--r-- | drivers/clk/mediatek/reset.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/clk/mediatek/reset.c b/drivers/clk/mediatek/reset.c new file mode 100644 index 000000000..290ceda84 --- /dev/null +++ b/drivers/clk/mediatek/reset.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2014 MediaTek Inc. + */ + +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include "reset.h" + +static inline struct mtk_clk_rst_data *to_mtk_clk_rst_data(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct mtk_clk_rst_data, rcdev); +} + +static int mtk_reset_update(struct reset_controller_dev *rcdev, + unsigned long id, bool deassert) +{ + struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev); + unsigned int val = deassert ? 0 : ~0; + + return regmap_update_bits(data->regmap, + data->desc->rst_bank_ofs[id / RST_NR_PER_BANK], + BIT(id % RST_NR_PER_BANK), val); +} + +static int mtk_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return mtk_reset_update(rcdev, id, false); +} + +static int mtk_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return mtk_reset_update(rcdev, id, true); +} + +static int mtk_reset(struct reset_controller_dev *rcdev, unsigned long id) +{ + int ret; + + ret = mtk_reset_assert(rcdev, id); + if (ret) + return ret; + + return mtk_reset_deassert(rcdev, id); +} + +static int mtk_reset_update_set_clr(struct reset_controller_dev *rcdev, + unsigned long id, bool deassert) +{ + struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev); + unsigned int deassert_ofs = deassert ? 0x4 : 0; + + return regmap_write(data->regmap, + data->desc->rst_bank_ofs[id / RST_NR_PER_BANK] + + deassert_ofs, + BIT(id % RST_NR_PER_BANK)); +} + +static int mtk_reset_assert_set_clr(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return mtk_reset_update_set_clr(rcdev, id, false); +} + +static int mtk_reset_deassert_set_clr(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return mtk_reset_update_set_clr(rcdev, id, true); +} + +static int mtk_reset_set_clr(struct reset_controller_dev *rcdev, + unsigned long id) +{ + int ret; + + ret = mtk_reset_assert_set_clr(rcdev, id); + if (ret) + return ret; + return mtk_reset_deassert_set_clr(rcdev, id); +} + +static const struct reset_control_ops mtk_reset_ops = { + .assert = mtk_reset_assert, + .deassert = mtk_reset_deassert, + .reset = mtk_reset, +}; + +static const struct reset_control_ops mtk_reset_ops_set_clr = { + .assert = mtk_reset_assert_set_clr, + .deassert = mtk_reset_deassert_set_clr, + .reset = mtk_reset_set_clr, +}; + +static int reset_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev); + + if (reset_spec->args[0] >= rcdev->nr_resets || + reset_spec->args[0] >= data->desc->rst_idx_map_nr) + return -EINVAL; + + return data->desc->rst_idx_map[reset_spec->args[0]]; +} + +int mtk_register_reset_controller(struct device_node *np, + const struct mtk_clk_rst_desc *desc) +{ + struct regmap *regmap; + const struct reset_control_ops *rcops = NULL; + struct mtk_clk_rst_data *data; + int ret; + + if (!desc) { + pr_err("mtk clock reset desc is NULL\n"); + return -EINVAL; + } + + switch (desc->version) { + case MTK_RST_SIMPLE: + rcops = &mtk_reset_ops; + break; + case MTK_RST_SET_CLR: + rcops = &mtk_reset_ops_set_clr; + break; + default: + pr_err("Unknown reset version %d\n", desc->version); + return -EINVAL; + } + + regmap = device_node_to_regmap(np); + if (IS_ERR(regmap)) { + pr_err("Cannot find regmap for %pOF: %pe\n", np, regmap); + return -EINVAL; + } + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->desc = desc; + data->regmap = regmap; + data->rcdev.owner = THIS_MODULE; + data->rcdev.ops = rcops; + data->rcdev.of_node = np; + + if (data->desc->rst_idx_map_nr > 0) { + data->rcdev.of_reset_n_cells = 1; + data->rcdev.nr_resets = desc->rst_idx_map_nr; + data->rcdev.of_xlate = reset_xlate; + } else { + data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK; + } + + ret = reset_controller_register(&data->rcdev); + if (ret) { + pr_err("could not register reset controller: %d\n", ret); + kfree(data); + return ret; + } + + return 0; +} + +int mtk_register_reset_controller_with_dev(struct device *dev, + const struct mtk_clk_rst_desc *desc) +{ + struct device_node *np = dev->of_node; + struct regmap *regmap; + const struct reset_control_ops *rcops = NULL; + struct mtk_clk_rst_data *data; + int ret; + + if (!desc) { + dev_err(dev, "mtk clock reset desc is NULL\n"); + return -EINVAL; + } + + switch (desc->version) { + case MTK_RST_SIMPLE: + rcops = &mtk_reset_ops; + break; + case MTK_RST_SET_CLR: + rcops = &mtk_reset_ops_set_clr; + break; + default: + dev_err(dev, "Unknown reset version %d\n", desc->version); + return -EINVAL; + } + + regmap = device_node_to_regmap(np); + if (IS_ERR(regmap)) { + dev_err(dev, "Cannot find regmap %pe\n", regmap); + return -EINVAL; + } + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->desc = desc; + data->regmap = regmap; + data->rcdev.owner = THIS_MODULE; + data->rcdev.ops = rcops; + data->rcdev.of_node = np; + data->rcdev.dev = dev; + + if (data->desc->rst_idx_map_nr > 0) { + data->rcdev.of_reset_n_cells = 1; + data->rcdev.nr_resets = desc->rst_idx_map_nr; + data->rcdev.of_xlate = reset_xlate; + } else { + data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK; + } + + ret = devm_reset_controller_register(dev, &data->rcdev); + if (ret) { + dev_err(dev, "could not register reset controller: %d\n", ret); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(mtk_register_reset_controller_with_dev); + +MODULE_LICENSE("GPL"); |