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 */
s10_protected_reg_write(void * base,unsigned int reg,unsigned int val)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 */
s10_protected_reg_read(void * base,unsigned int reg,unsigned int * val)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 * altr_sysmgr_regmap_lookup_by_phandle
92 * Find the sysmgr previous configured in probe() and return regmap property.
93 * Return: regmap if found or error if not found.
94 */
altr_sysmgr_regmap_lookup_by_phandle(struct device_node * np,const char * property)95 struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
96 const char *property)
97 {
98 struct device *dev;
99 struct altr_sysmgr *sysmgr;
100 struct device_node *sysmgr_np;
101
102 if (property)
103 sysmgr_np = of_parse_phandle(np, property, 0);
104 else
105 sysmgr_np = np;
106
107 if (!sysmgr_np)
108 return ERR_PTR(-ENODEV);
109
110 dev = driver_find_device_by_of_node(&altr_sysmgr_driver.driver,
111 (void *)sysmgr_np);
112 if (property)
113 of_node_put(sysmgr_np);
114
115 if (!dev)
116 return ERR_PTR(-EPROBE_DEFER);
117
118 sysmgr = dev_get_drvdata(dev);
119
120 return sysmgr->regmap;
121 }
122 EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
123
sysmgr_probe(struct platform_device * pdev)124 static int sysmgr_probe(struct platform_device *pdev)
125 {
126 struct altr_sysmgr *sysmgr;
127 struct regmap *regmap;
128 struct resource *res;
129 struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg;
130 struct device *dev = &pdev->dev;
131 struct device_node *np = dev->of_node;
132
133 sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
134 if (!sysmgr)
135 return -ENOMEM;
136
137 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
138 if (!res)
139 return -ENOENT;
140
141 sysmgr_config.max_register = resource_size(res) -
142 sysmgr_config.reg_stride;
143 if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
144 /* Need physical address for SMCC call */
145 sysmgr->base = (resource_size_t *)res->start;
146 sysmgr_config.reg_read = s10_protected_reg_read;
147 sysmgr_config.reg_write = s10_protected_reg_write;
148
149 regmap = devm_regmap_init(dev, NULL, sysmgr->base,
150 &sysmgr_config);
151 } else {
152 sysmgr->base = devm_ioremap(dev, res->start,
153 resource_size(res));
154 if (!sysmgr->base)
155 return -ENOMEM;
156
157 sysmgr_config.max_register = res->end - res->start - 3;
158 regmap = devm_regmap_init_mmio(dev, sysmgr->base,
159 &sysmgr_config);
160 }
161
162 if (IS_ERR(regmap)) {
163 pr_err("regmap init failed\n");
164 return PTR_ERR(regmap);
165 }
166
167 sysmgr->regmap = regmap;
168
169 platform_set_drvdata(pdev, sysmgr);
170
171 return 0;
172 }
173
174 static const struct of_device_id altr_sysmgr_of_match[] = {
175 { .compatible = "altr,sys-mgr" },
176 { .compatible = "altr,sys-mgr-s10" },
177 {},
178 };
179 MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);
180
181 static struct platform_driver altr_sysmgr_driver = {
182 .probe = sysmgr_probe,
183 .driver = {
184 .name = "altr,system_manager",
185 .of_match_table = altr_sysmgr_of_match,
186 },
187 };
188
altr_sysmgr_init(void)189 static int __init altr_sysmgr_init(void)
190 {
191 return platform_driver_register(&altr_sysmgr_driver);
192 }
193 core_initcall(altr_sysmgr_init);
194
altr_sysmgr_exit(void)195 static void __exit altr_sysmgr_exit(void)
196 {
197 platform_driver_unregister(&altr_sysmgr_driver);
198 }
199 module_exit(altr_sysmgr_exit);
200
201 MODULE_AUTHOR("Thor Thayer <>");
202 MODULE_DESCRIPTION("SOCFPGA System Manager driver");
203 MODULE_LICENSE("GPL v2");
204