1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
2 /*
3 * Microsemi MIPS SoC reset driver
4 *
5 * License: Dual MIT/GPL
6 * Copyright (c) 2017 Microsemi Corporation
7 */
8 #include <linux/delay.h>
9 #include <linux/io.h>
10 #include <linux/notifier.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/platform_device.h>
14 #include <linux/property.h>
15 #include <linux/reboot.h>
16 #include <linux/regmap.h>
17
18 struct reset_props {
19 const char *syscon;
20 u32 protect_reg;
21 u32 vcore_protect;
22 u32 if_si_owner_bit;
23 };
24
25 struct ocelot_reset_context {
26 void __iomem *base;
27 struct regmap *cpu_ctrl;
28 const struct reset_props *props;
29 struct notifier_block restart_handler;
30 };
31
32 #define BIT_OFF_INVALID 32
33
34 #define SOFT_CHIP_RST BIT(0)
35
36 #define ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
37 #define IF_SI_OWNER_MASK GENMASK(1, 0)
38 #define IF_SI_OWNER_SISL 0
39 #define IF_SI_OWNER_SIBM 1
40 #define IF_SI_OWNER_SIMC 2
41
ocelot_restart_handle(struct notifier_block * this,unsigned long mode,void * cmd)42 static int ocelot_restart_handle(struct notifier_block *this,
43 unsigned long mode, void *cmd)
44 {
45 struct ocelot_reset_context *ctx = container_of(this, struct
46 ocelot_reset_context,
47 restart_handler);
48 u32 if_si_owner_bit = ctx->props->if_si_owner_bit;
49
50 /* Make sure the core is not protected from reset */
51 regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg,
52 ctx->props->vcore_protect, 0);
53
54 /* Make the SI back to boot mode */
55 if (if_si_owner_bit != BIT_OFF_INVALID)
56 regmap_update_bits(ctx->cpu_ctrl,
57 ICPU_CFG_CPU_SYSTEM_CTRL_GENERAL_CTRL,
58 IF_SI_OWNER_MASK << if_si_owner_bit,
59 IF_SI_OWNER_SIBM << if_si_owner_bit);
60
61 pr_emerg("Resetting SoC\n");
62
63 writel(SOFT_CHIP_RST, ctx->base);
64
65 pr_emerg("Unable to restart system\n");
66 return NOTIFY_DONE;
67 }
68
ocelot_reset_probe(struct platform_device * pdev)69 static int ocelot_reset_probe(struct platform_device *pdev)
70 {
71 struct ocelot_reset_context *ctx;
72 struct device *dev = &pdev->dev;
73 int err;
74
75 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
76 if (!ctx)
77 return -ENOMEM;
78
79 ctx->base = devm_platform_ioremap_resource(pdev, 0);
80 if (IS_ERR(ctx->base))
81 return PTR_ERR(ctx->base);
82
83 ctx->props = device_get_match_data(dev);
84
85 ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible(ctx->props->syscon);
86 if (IS_ERR(ctx->cpu_ctrl)) {
87 dev_err(dev, "No syscon map: %s\n", ctx->props->syscon);
88 return PTR_ERR(ctx->cpu_ctrl);
89 }
90
91 ctx->restart_handler.notifier_call = ocelot_restart_handle;
92 ctx->restart_handler.priority = 192;
93 err = register_restart_handler(&ctx->restart_handler);
94 if (err)
95 dev_err(dev, "can't register restart notifier (err=%d)\n", err);
96
97 return err;
98 }
99
100 static const struct reset_props reset_props_jaguar2 = {
101 .syscon = "mscc,ocelot-cpu-syscon",
102 .protect_reg = 0x20,
103 .vcore_protect = BIT(2),
104 .if_si_owner_bit = 6,
105 };
106
107 static const struct reset_props reset_props_luton = {
108 .syscon = "mscc,ocelot-cpu-syscon",
109 .protect_reg = 0x20,
110 .vcore_protect = BIT(2),
111 .if_si_owner_bit = BIT_OFF_INVALID, /* n/a */
112 };
113
114 static const struct reset_props reset_props_ocelot = {
115 .syscon = "mscc,ocelot-cpu-syscon",
116 .protect_reg = 0x20,
117 .vcore_protect = BIT(2),
118 .if_si_owner_bit = 4,
119 };
120
121 static const struct reset_props reset_props_sparx5 = {
122 .syscon = "microchip,sparx5-cpu-syscon",
123 .protect_reg = 0x84,
124 .vcore_protect = BIT(10),
125 .if_si_owner_bit = 6,
126 };
127
128 static const struct of_device_id ocelot_reset_of_match[] = {
129 {
130 .compatible = "mscc,jaguar2-chip-reset",
131 .data = &reset_props_jaguar2
132 }, {
133 .compatible = "mscc,luton-chip-reset",
134 .data = &reset_props_luton
135 }, {
136 .compatible = "mscc,ocelot-chip-reset",
137 .data = &reset_props_ocelot
138 }, {
139 .compatible = "microchip,sparx5-chip-reset",
140 .data = &reset_props_sparx5
141 },
142 { /*sentinel*/ }
143 };
144
145 static struct platform_driver ocelot_reset_driver = {
146 .probe = ocelot_reset_probe,
147 .driver = {
148 .name = "ocelot-chip-reset",
149 .of_match_table = ocelot_reset_of_match,
150 },
151 };
152 builtin_platform_driver(ocelot_reset_driver);
153