1 // SPDX-License-Identifier: GPL-2.0+ 2 /* Microchip Sparx5 Switch Reset driver 3 * 4 * Copyright (c) 2020 Microchip Technology Inc. and its subsidiaries. 5 * 6 * The Sparx5 Chip Register Model can be browsed at this location: 7 * https://github.com/microchip-ung/sparx-5_reginfo 8 */ 9 #include <linux/mfd/syscon.h> 10 #include <linux/of_device.h> 11 #include <linux/module.h> 12 #include <linux/platform_device.h> 13 #include <linux/regmap.h> 14 #include <linux/reset-controller.h> 15 16 struct reset_props { 17 u32 protect_reg; 18 u32 protect_bit; 19 u32 reset_reg; 20 u32 reset_bit; 21 }; 22 23 struct mchp_reset_context { 24 struct regmap *cpu_ctrl; 25 struct regmap *gcb_ctrl; 26 struct reset_controller_dev rcdev; 27 const struct reset_props *props; 28 }; 29 30 static struct regmap_config sparx5_reset_regmap_config = { 31 .reg_bits = 32, 32 .val_bits = 32, 33 .reg_stride = 4, 34 }; 35 36 static int sparx5_switch_reset(struct reset_controller_dev *rcdev, 37 unsigned long id) 38 { 39 struct mchp_reset_context *ctx = 40 container_of(rcdev, struct mchp_reset_context, rcdev); 41 u32 val; 42 43 /* Make sure the core is PROTECTED from reset */ 44 regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg, 45 ctx->props->protect_bit, ctx->props->protect_bit); 46 47 /* Start soft reset */ 48 regmap_write(ctx->gcb_ctrl, ctx->props->reset_reg, 49 ctx->props->reset_bit); 50 51 /* Wait for soft reset done */ 52 return regmap_read_poll_timeout(ctx->gcb_ctrl, ctx->props->reset_reg, val, 53 (val & ctx->props->reset_bit) == 0, 54 1, 100); 55 } 56 57 static const struct reset_control_ops sparx5_reset_ops = { 58 .reset = sparx5_switch_reset, 59 }; 60 61 static int mchp_sparx5_map_syscon(struct platform_device *pdev, char *name, 62 struct regmap **target) 63 { 64 struct device_node *syscon_np; 65 struct regmap *regmap; 66 int err; 67 68 syscon_np = of_parse_phandle(pdev->dev.of_node, name, 0); 69 if (!syscon_np) 70 return -ENODEV; 71 regmap = syscon_node_to_regmap(syscon_np); 72 of_node_put(syscon_np); 73 if (IS_ERR(regmap)) { 74 err = PTR_ERR(regmap); 75 dev_err(&pdev->dev, "No '%s' map: %d\n", name, err); 76 return err; 77 } 78 *target = regmap; 79 return 0; 80 } 81 82 static int mchp_sparx5_map_io(struct platform_device *pdev, int index, 83 struct regmap **target) 84 { 85 struct resource *res; 86 struct regmap *map; 87 void __iomem *mem; 88 89 mem = devm_platform_get_and_ioremap_resource(pdev, index, &res); 90 if (IS_ERR(mem)) { 91 dev_err(&pdev->dev, "Could not map resource %d\n", index); 92 return PTR_ERR(mem); 93 } 94 sparx5_reset_regmap_config.name = res->name; 95 map = devm_regmap_init_mmio(&pdev->dev, mem, &sparx5_reset_regmap_config); 96 if (IS_ERR(map)) 97 return PTR_ERR(map); 98 *target = map; 99 return 0; 100 } 101 102 static int mchp_sparx5_reset_probe(struct platform_device *pdev) 103 { 104 struct device_node *dn = pdev->dev.of_node; 105 struct mchp_reset_context *ctx; 106 int err; 107 108 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); 109 if (!ctx) 110 return -ENOMEM; 111 112 err = mchp_sparx5_map_syscon(pdev, "cpu-syscon", &ctx->cpu_ctrl); 113 if (err) 114 return err; 115 err = mchp_sparx5_map_io(pdev, 0, &ctx->gcb_ctrl); 116 if (err) 117 return err; 118 119 ctx->rcdev.owner = THIS_MODULE; 120 ctx->rcdev.nr_resets = 1; 121 ctx->rcdev.ops = &sparx5_reset_ops; 122 ctx->rcdev.of_node = dn; 123 ctx->props = device_get_match_data(&pdev->dev); 124 125 return devm_reset_controller_register(&pdev->dev, &ctx->rcdev); 126 } 127 128 static const struct reset_props reset_props_sparx5 = { 129 .protect_reg = 0x84, 130 .protect_bit = BIT(10), 131 .reset_reg = 0x0, 132 .reset_bit = BIT(1), 133 }; 134 135 static const struct reset_props reset_props_lan966x = { 136 .protect_reg = 0x88, 137 .protect_bit = BIT(5), 138 .reset_reg = 0x0, 139 .reset_bit = BIT(1), 140 }; 141 142 static const struct of_device_id mchp_sparx5_reset_of_match[] = { 143 { 144 .compatible = "microchip,sparx5-switch-reset", 145 .data = &reset_props_sparx5, 146 }, { 147 .compatible = "microchip,lan966x-switch-reset", 148 .data = &reset_props_lan966x, 149 }, 150 { } 151 }; 152 153 static struct platform_driver mchp_sparx5_reset_driver = { 154 .probe = mchp_sparx5_reset_probe, 155 .driver = { 156 .name = "sparx5-switch-reset", 157 .of_match_table = mchp_sparx5_reset_of_match, 158 }, 159 }; 160 161 static int __init mchp_sparx5_reset_init(void) 162 { 163 return platform_driver_register(&mchp_sparx5_reset_driver); 164 } 165 166 postcore_initcall(mchp_sparx5_reset_init); 167 168 MODULE_DESCRIPTION("Microchip Sparx5 switch reset driver"); 169 MODULE_AUTHOR("Steen Hegelund <steen.hegelund@microchip.com>"); 170 MODULE_LICENSE("Dual MIT/GPL"); 171