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5a2308da9f
Add a reset controller driver for the Canaan Kendryte K210 SoC. This driver relies on its syscon compatible parent node (sysctl) for its register mapping. Default this driver compilation to y when the SOC_CANAAN option is selected. The MAINTAINERS file is updated, adding the entry "CANAAN/KENDRYTE K210 SOC RESET CONTROLLER DRIVER" with myself listed as maintainer for this driver. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
132 lines
3.0 KiB
C
132 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) 2020 Western Digital Corporation or its affiliates.
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*/
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/reset-controller.h>
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#include <linux/delay.h>
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#include <linux/mfd/syscon.h>
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#include <linux/regmap.h>
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#include <soc/canaan/k210-sysctl.h>
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#include <dt-bindings/reset/k210-rst.h>
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#define K210_RST_MASK 0x27FFFFFF
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struct k210_rst {
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struct regmap *map;
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struct reset_controller_dev rcdev;
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};
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static inline struct k210_rst *
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to_k210_rst(struct reset_controller_dev *rcdev)
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{
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return container_of(rcdev, struct k210_rst, rcdev);
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}
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static inline int k210_rst_assert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct k210_rst *ksr = to_k210_rst(rcdev);
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return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1);
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}
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static inline int k210_rst_deassert(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct k210_rst *ksr = to_k210_rst(rcdev);
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return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0);
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}
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static int k210_rst_reset(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 = k210_rst_assert(rcdev, id);
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if (ret == 0) {
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udelay(10);
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ret = k210_rst_deassert(rcdev, id);
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}
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return ret;
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}
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static int k210_rst_status(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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struct k210_rst *ksr = to_k210_rst(rcdev);
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u32 reg, bit = BIT(id);
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int ret;
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ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, ®);
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if (ret)
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return ret;
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return reg & bit;
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}
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static int k210_rst_xlate(struct reset_controller_dev *rcdev,
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const struct of_phandle_args *reset_spec)
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{
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unsigned long id = reset_spec->args[0];
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if (!(BIT(id) & K210_RST_MASK))
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return -EINVAL;
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return id;
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}
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static const struct reset_control_ops k210_rst_ops = {
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.assert = k210_rst_assert,
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.deassert = k210_rst_deassert,
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.reset = k210_rst_reset,
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.status = k210_rst_status,
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};
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static int k210_rst_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *parent_np = of_get_parent(dev->of_node);
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struct k210_rst *ksr;
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dev_info(dev, "K210 reset controller\n");
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ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);
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if (!ksr)
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return -ENOMEM;
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ksr->map = syscon_node_to_regmap(parent_np);
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of_node_put(parent_np);
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if (IS_ERR(ksr->map))
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return PTR_ERR(ksr->map);
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ksr->rcdev.owner = THIS_MODULE;
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ksr->rcdev.dev = dev;
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ksr->rcdev.of_node = dev->of_node;
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ksr->rcdev.ops = &k210_rst_ops;
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ksr->rcdev.nr_resets = fls(K210_RST_MASK);
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ksr->rcdev.of_reset_n_cells = 1;
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ksr->rcdev.of_xlate = k210_rst_xlate;
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return devm_reset_controller_register(dev, &ksr->rcdev);
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}
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static const struct of_device_id k210_rst_dt_ids[] = {
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{ .compatible = "canaan,k210-rst" },
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{ /* sentinel */ },
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};
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static struct platform_driver k210_rst_driver = {
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.probe = k210_rst_probe,
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.driver = {
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.name = "k210-rst",
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.of_match_table = k210_rst_dt_ids,
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},
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};
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builtin_platform_driver(k210_rst_driver);
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