1 // SPDX-License-Identifier: GPL-2.0+
2 /* Microchip Sparx5 Switch Reset driver
4 * Copyright (c) 2020 Microchip Technology Inc. and its subsidiaries.
6 * The Sparx5 Chip Register Model can be browsed at this location:
7 * https://github.com/microchip-ung/sparx-5_reginfo
9 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/property.h>
14 #include <linux/regmap.h>
15 #include <linux/reset-controller.h>
24 struct mchp_reset_context {
25 struct regmap *cpu_ctrl;
26 struct regmap *gcb_ctrl;
27 struct reset_controller_dev rcdev;
28 const struct reset_props *props;
31 static struct regmap_config sparx5_reset_regmap_config = {
37 static int sparx5_switch_reset(struct mchp_reset_context *ctx)
41 /* Make sure the core is PROTECTED from reset */
42 regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg,
43 ctx->props->protect_bit, ctx->props->protect_bit);
45 /* Start soft reset */
46 regmap_write(ctx->gcb_ctrl, ctx->props->reset_reg,
47 ctx->props->reset_bit);
49 /* Wait for soft reset done */
50 return regmap_read_poll_timeout(ctx->gcb_ctrl, ctx->props->reset_reg, val,
51 (val & ctx->props->reset_bit) == 0,
55 static int sparx5_reset_noop(struct reset_controller_dev *rcdev,
61 static const struct reset_control_ops sparx5_reset_ops = {
62 .reset = sparx5_reset_noop,
65 static const struct regmap_config mchp_lan966x_syscon_regmap_config = {
71 static struct regmap *mchp_lan966x_syscon_to_regmap(struct device *dev,
72 struct device_node *syscon_np)
74 struct regmap_config regmap_config = mchp_lan966x_syscon_regmap_config;
78 base = devm_of_iomap(dev, syscon_np, 0, &size);
80 return ERR_CAST(base);
82 regmap_config.max_register = size - 4;
84 return devm_regmap_init_mmio(dev, base, ®map_config);
87 static int mchp_sparx5_map_syscon(struct platform_device *pdev, char *name,
88 struct regmap **target)
90 struct device_node *syscon_np;
91 struct regmap *regmap;
94 syscon_np = of_parse_phandle(pdev->dev.of_node, name, 0);
99 * The syscon API doesn't support syscon device removal.
100 * When used in LAN966x PCI device, the cpu-syscon device needs to be
101 * removed when the PCI device is removed.
102 * In case of LAN966x, map the syscon device locally to support the
105 if (of_device_is_compatible(pdev->dev.of_node, "microchip,lan966x-switch-reset"))
106 regmap = mchp_lan966x_syscon_to_regmap(&pdev->dev, syscon_np);
108 regmap = syscon_node_to_regmap(syscon_np);
109 of_node_put(syscon_np);
110 if (IS_ERR(regmap)) {
111 err = PTR_ERR(regmap);
112 dev_err(&pdev->dev, "No '%s' map: %d\n", name, err);
119 static int mchp_sparx5_map_io(struct platform_device *pdev, int index,
120 struct regmap **target)
122 struct resource *res;
126 mem = devm_platform_get_and_ioremap_resource(pdev, index, &res);
128 dev_err(&pdev->dev, "Could not map resource %d\n", index);
131 sparx5_reset_regmap_config.name = res->name;
132 map = devm_regmap_init_mmio(&pdev->dev, mem, &sparx5_reset_regmap_config);
139 static int mchp_sparx5_reset_probe(struct platform_device *pdev)
141 struct device_node *dn = pdev->dev.of_node;
142 struct mchp_reset_context *ctx;
145 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
149 err = mchp_sparx5_map_syscon(pdev, "cpu-syscon", &ctx->cpu_ctrl);
152 err = mchp_sparx5_map_io(pdev, 0, &ctx->gcb_ctrl);
156 ctx->rcdev.owner = THIS_MODULE;
157 ctx->rcdev.dev = &pdev->dev;
158 ctx->rcdev.nr_resets = 1;
159 ctx->rcdev.ops = &sparx5_reset_ops;
160 ctx->rcdev.of_node = dn;
161 ctx->props = device_get_match_data(&pdev->dev);
163 /* Issue the reset very early, our actual reset callback is a noop. */
164 err = sparx5_switch_reset(ctx);
168 return devm_reset_controller_register(&pdev->dev, &ctx->rcdev);
171 static const struct reset_props reset_props_sparx5 = {
173 .protect_bit = BIT(10),
178 static const struct reset_props reset_props_lan966x = {
180 .protect_bit = BIT(5),
185 static const struct of_device_id mchp_sparx5_reset_of_match[] = {
187 .compatible = "microchip,sparx5-switch-reset",
188 .data = &reset_props_sparx5,
190 .compatible = "microchip,lan966x-switch-reset",
191 .data = &reset_props_lan966x,
195 MODULE_DEVICE_TABLE(of, mchp_sparx5_reset_of_match);
197 static struct platform_driver mchp_sparx5_reset_driver = {
198 .probe = mchp_sparx5_reset_probe,
200 .name = "sparx5-switch-reset",
201 .of_match_table = mchp_sparx5_reset_of_match,
205 static int __init mchp_sparx5_reset_init(void)
207 return platform_driver_register(&mchp_sparx5_reset_driver);
211 * Because this is a global reset, keep this postcore_initcall() to issue the
212 * reset as early as possible during the kernel startup.
214 postcore_initcall(mchp_sparx5_reset_init);
216 MODULE_DESCRIPTION("Microchip Sparx5 switch reset driver");
218 MODULE_LICENSE("GPL");