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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | // SPDX-License-Identifier: GPL-2.0 /* * Broadcom STB generic reset controller for SW_INIT style reset controller * * Author: Florian Fainelli <f.fainelli@gmail.com> * Copyright (C) 2018 Broadcom */ #include <linux/delay.h> #include <linux/device.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/reset-controller.h> #include <linux/types.h> struct brcmstb_reset { void __iomem *base; struct reset_controller_dev rcdev; }; #define SW_INIT_SET 0x00 #define SW_INIT_CLEAR 0x04 #define SW_INIT_STATUS 0x08 #define SW_INIT_BIT(id) BIT((id) & 0x1f) #define SW_INIT_BANK(id) ((id) >> 5) /* A full bank contains extra registers that we are not utilizing but still * qualify as a single bank. */ #define SW_INIT_BANK_SIZE 0x18 static inline struct brcmstb_reset *to_brcmstb(struct reset_controller_dev *rcdev) { return container_of(rcdev, struct brcmstb_reset, rcdev); } static int brcmstb_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) { unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE; struct brcmstb_reset *priv = to_brcmstb(rcdev); writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_SET); return 0; } static int brcmstb_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) { unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE; struct brcmstb_reset *priv = to_brcmstb(rcdev); writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_CLEAR); /* Maximum reset delay after de-asserting a line and seeing block * operation is typically 14us for the worst case, build some slack * here. */ usleep_range(100, 200); return 0; } static int brcmstb_reset_status(struct reset_controller_dev *rcdev, unsigned long id) { unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE; struct brcmstb_reset *priv = to_brcmstb(rcdev); return readl_relaxed(priv->base + off + SW_INIT_STATUS) & SW_INIT_BIT(id); } static const struct reset_control_ops brcmstb_reset_ops = { .assert = brcmstb_reset_assert, .deassert = brcmstb_reset_deassert, .status = brcmstb_reset_status, }; static int brcmstb_reset_probe(struct platform_device *pdev) { struct device *kdev = &pdev->dev; struct brcmstb_reset *priv; struct resource *res; priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(priv->base)) return PTR_ERR(priv->base); dev_set_drvdata(kdev, priv); priv->rcdev.owner = THIS_MODULE; priv->rcdev.nr_resets = DIV_ROUND_DOWN_ULL(resource_size(res), SW_INIT_BANK_SIZE) * 32; priv->rcdev.ops = &brcmstb_reset_ops; priv->rcdev.of_node = kdev->of_node; /* Use defaults: 1 cell and simple xlate function */ return devm_reset_controller_register(kdev, &priv->rcdev); } static const struct of_device_id brcmstb_reset_of_match[] = { { .compatible = "brcm,brcmstb-reset" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, brcmstb_reset_of_match); static struct platform_driver brcmstb_reset_driver = { .probe = brcmstb_reset_probe, .driver = { .name = "brcmstb-reset", .of_match_table = brcmstb_reset_of_match, }, }; module_platform_driver(brcmstb_reset_driver); MODULE_AUTHOR("Broadcom"); MODULE_DESCRIPTION("Broadcom STB reset controller"); MODULE_LICENSE("GPL"); |