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1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright (C) 2018-2019, Intel Corporation. | |
4 | * Copyright (C) 2012 Freescale Semiconductor, Inc. | |
5 | * Copyright (C) 2012 Linaro Ltd. | |
6 | * | |
7 | * Based on syscon driver. | |
8 | */ | |
9 | ||
10 | #include <linux/arm-smccc.h> | |
11 | #include <linux/err.h> | |
12 | #include <linux/io.h> | |
13 | #include <linux/mfd/altera-sysmgr.h> | |
14 | #include <linux/mfd/syscon.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/of_address.h> | |
18 | #include <linux/of_platform.h> | |
19 | #include <linux/regmap.h> | |
20 | #include <linux/slab.h> | |
21 | ||
22 | /** | |
23 | * struct altr_sysmgr - Altera SOCFPGA System Manager | |
24 | * @regmap: the regmap used for System Manager accesses. | |
25 | * @base : the base address for the System Manager | |
26 | */ | |
27 | struct altr_sysmgr { | |
28 | struct regmap *regmap; | |
29 | resource_size_t *base; | |
30 | }; | |
31 | ||
32 | static struct platform_driver altr_sysmgr_driver; | |
33 | ||
34 | /** | |
35 | * s10_protected_reg_write | |
36 | * Write to a protected SMC register. | |
37 | * @base: Base address of System Manager | |
38 | * @reg: Address offset of register | |
39 | * @val: Value to write | |
40 | * Return: INTEL_SIP_SMC_STATUS_OK (0) on success | |
41 | * INTEL_SIP_SMC_REG_ERROR on error | |
42 | * INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported | |
43 | */ | |
44 | static int s10_protected_reg_write(void *base, | |
45 | unsigned int reg, unsigned int val) | |
46 | { | |
47 | struct arm_smccc_res result; | |
48 | unsigned long sysmgr_base = (unsigned long)base; | |
49 | ||
50 | arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg, | |
51 | val, 0, 0, 0, 0, 0, &result); | |
52 | ||
53 | return (int)result.a0; | |
54 | } | |
55 | ||
56 | /** | |
57 | * s10_protected_reg_read | |
58 | * Read the status of a protected SMC register | |
59 | * @base: Base address of System Manager. | |
60 | * @reg: Address of register | |
61 | * @val: Value read. | |
62 | * Return: INTEL_SIP_SMC_STATUS_OK (0) on success | |
63 | * INTEL_SIP_SMC_REG_ERROR on error | |
64 | * INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported | |
65 | */ | |
66 | static int s10_protected_reg_read(void *base, | |
67 | unsigned int reg, unsigned int *val) | |
68 | { | |
69 | struct arm_smccc_res result; | |
70 | unsigned long sysmgr_base = (unsigned long)base; | |
71 | ||
72 | arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg, | |
73 | 0, 0, 0, 0, 0, 0, &result); | |
74 | ||
75 | *val = (unsigned int)result.a1; | |
76 | ||
77 | return (int)result.a0; | |
78 | } | |
79 | ||
80 | static struct regmap_config altr_sysmgr_regmap_cfg = { | |
81 | .name = "altr_sysmgr", | |
82 | .reg_bits = 32, | |
83 | .reg_stride = 4, | |
84 | .val_bits = 32, | |
85 | .fast_io = true, | |
86 | .use_single_read = true, | |
87 | .use_single_write = true, | |
88 | }; | |
89 | ||
90 | /** | |
91 | * sysmgr_match_phandle | |
92 | * Matching function used by driver_find_device(). | |
93 | * Return: True if match is found, otherwise false. | |
94 | */ | |
95 | static int sysmgr_match_phandle(struct device *dev, void *data) | |
96 | { | |
97 | return dev->of_node == (struct device_node *)data; | |
98 | } | |
99 | ||
100 | /** | |
101 | * altr_sysmgr_regmap_lookup_by_phandle | |
102 | * Find the sysmgr previous configured in probe() and return regmap property. | |
103 | * Return: regmap if found or error if not found. | |
104 | */ | |
105 | struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np, | |
106 | const char *property) | |
107 | { | |
108 | struct device *dev; | |
109 | struct altr_sysmgr *sysmgr; | |
110 | struct device_node *sysmgr_np; | |
111 | ||
112 | if (property) | |
113 | sysmgr_np = of_parse_phandle(np, property, 0); | |
114 | else | |
115 | sysmgr_np = np; | |
116 | ||
117 | if (!sysmgr_np) | |
118 | return ERR_PTR(-ENODEV); | |
119 | ||
120 | dev = driver_find_device(&altr_sysmgr_driver.driver, NULL, | |
121 | (void *)sysmgr_np, sysmgr_match_phandle); | |
122 | of_node_put(sysmgr_np); | |
123 | if (!dev) | |
124 | return ERR_PTR(-EPROBE_DEFER); | |
125 | ||
126 | sysmgr = dev_get_drvdata(dev); | |
127 | ||
128 | return sysmgr->regmap; | |
129 | } | |
130 | EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle); | |
131 | ||
132 | static int sysmgr_probe(struct platform_device *pdev) | |
133 | { | |
134 | struct altr_sysmgr *sysmgr; | |
135 | struct regmap *regmap; | |
136 | struct resource *res; | |
137 | struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg; | |
138 | struct device *dev = &pdev->dev; | |
139 | struct device_node *np = dev->of_node; | |
140 | ||
141 | sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL); | |
142 | if (!sysmgr) | |
143 | return -ENOMEM; | |
144 | ||
145 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
146 | if (!res) | |
147 | return -ENOENT; | |
148 | ||
149 | sysmgr_config.max_register = resource_size(res) - | |
150 | sysmgr_config.reg_stride; | |
151 | if (of_device_is_compatible(np, "altr,sys-mgr-s10")) { | |
152 | /* Need physical address for SMCC call */ | |
153 | sysmgr->base = (resource_size_t *)res->start; | |
154 | sysmgr_config.reg_read = s10_protected_reg_read; | |
155 | sysmgr_config.reg_write = s10_protected_reg_write; | |
156 | ||
157 | regmap = devm_regmap_init(dev, NULL, sysmgr->base, | |
158 | &sysmgr_config); | |
159 | } else { | |
160 | sysmgr->base = devm_ioremap(dev, res->start, | |
161 | resource_size(res)); | |
162 | if (!sysmgr->base) | |
163 | return -ENOMEM; | |
164 | ||
165 | sysmgr_config.max_register = res->end - res->start - 3; | |
166 | regmap = devm_regmap_init_mmio(dev, sysmgr->base, | |
167 | &sysmgr_config); | |
168 | } | |
169 | ||
170 | if (IS_ERR(regmap)) { | |
171 | pr_err("regmap init failed\n"); | |
172 | return PTR_ERR(regmap); | |
173 | } | |
174 | ||
175 | sysmgr->regmap = regmap; | |
176 | ||
177 | platform_set_drvdata(pdev, sysmgr); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | static const struct of_device_id altr_sysmgr_of_match[] = { | |
183 | { .compatible = "altr,sys-mgr" }, | |
184 | { .compatible = "altr,sys-mgr-s10" }, | |
185 | {}, | |
186 | }; | |
187 | MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match); | |
188 | ||
189 | static struct platform_driver altr_sysmgr_driver = { | |
190 | .probe = sysmgr_probe, | |
191 | .driver = { | |
192 | .name = "altr,system_manager", | |
193 | .of_match_table = altr_sysmgr_of_match, | |
194 | }, | |
195 | }; | |
196 | ||
197 | static int __init altr_sysmgr_init(void) | |
198 | { | |
199 | return platform_driver_register(&altr_sysmgr_driver); | |
200 | } | |
201 | core_initcall(altr_sysmgr_init); | |
202 | ||
203 | static void __exit altr_sysmgr_exit(void) | |
204 | { | |
205 | platform_driver_unregister(&altr_sysmgr_driver); | |
206 | } | |
207 | module_exit(altr_sysmgr_exit); | |
208 | ||
209 | MODULE_AUTHOR("Thor Thayer <>"); | |
210 | MODULE_DESCRIPTION("SOCFPGA System Manager driver"); | |
211 | MODULE_LICENSE("GPL v2"); |