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/platform_device.h>
18 #include <linux/regmap.h>
19 #include <linux/slab.h>
20
21 /**
22 * struct altr_sysmgr - Altera SOCFPGA System Manager
23 * @regmap: the regmap used for System Manager accesses.
24 */
25 struct altr_sysmgr {
26 struct regmap *regmap;
27 };
28
29 static struct platform_driver altr_sysmgr_driver;
30
31 /**
32 * s10_protected_reg_write
33 * Write to a protected SMC register.
34 * @base: Base address of System Manager
35 * @reg: Address offset of register
36 * @val: Value to write
37 * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
38 * INTEL_SIP_SMC_REG_ERROR on error
39 * INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
40 */
s10_protected_reg_write(void * base,unsigned int reg,unsigned int val)41 static int s10_protected_reg_write(void *base,
42 unsigned int reg, unsigned int val)
43 {
44 struct arm_smccc_res result;
45 unsigned long sysmgr_base = (unsigned long)base;
46
47 arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg,
48 val, 0, 0, 0, 0, 0, &result);
49
50 return (int)result.a0;
51 }
52
53 /**
54 * s10_protected_reg_read
55 * Read the status of a protected SMC register
56 * @base: Base address of System Manager.
57 * @reg: Address of register
58 * @val: Value read.
59 * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
60 * INTEL_SIP_SMC_REG_ERROR on error
61 * INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
62 */
s10_protected_reg_read(void * base,unsigned int reg,unsigned int * val)63 static int s10_protected_reg_read(void *base,
64 unsigned int reg, unsigned int *val)
65 {
66 struct arm_smccc_res result;
67 unsigned long sysmgr_base = (unsigned long)base;
68
69 arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg,
70 0, 0, 0, 0, 0, 0, &result);
71
72 *val = (unsigned int)result.a1;
73
74 return (int)result.a0;
75 }
76
77 static struct regmap_config altr_sysmgr_regmap_cfg = {
78 .name = "altr_sysmgr",
79 .reg_bits = 32,
80 .reg_stride = 4,
81 .val_bits = 32,
82 .fast_io = true,
83 .use_single_read = true,
84 .use_single_write = true,
85 };
86
87 /**
88 * altr_sysmgr_regmap_lookup_by_phandle
89 * Find the sysmgr previous configured in probe() and return regmap property.
90 * Return: regmap if found or error if not found.
91 *
92 * @np: Pointer to device's Device Tree node
93 * @property: Device Tree property name which references the sysmgr
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 void __iomem *base;
133
134 sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
135 if (!sysmgr)
136 return -ENOMEM;
137
138 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
139 if (!res)
140 return -ENOENT;
141
142 sysmgr_config.max_register = resource_size(res) -
143 sysmgr_config.reg_stride;
144 if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
145 sysmgr_config.reg_read = s10_protected_reg_read;
146 sysmgr_config.reg_write = s10_protected_reg_write;
147
148 /* Need physical address for SMCC call */
149 regmap = devm_regmap_init(dev, NULL,
150 (void *)(uintptr_t)res->start,
151 &sysmgr_config);
152 } else {
153 base = devm_ioremap(dev, res->start, resource_size(res));
154 if (!base)
155 return -ENOMEM;
156
157 sysmgr_config.max_register = resource_size(res) - 4;
158 regmap = devm_regmap_init_mmio(dev, base, &sysmgr_config);
159 }
160
161 if (IS_ERR(regmap)) {
162 pr_err("regmap init failed\n");
163 return PTR_ERR(regmap);
164 }
165
166 sysmgr->regmap = regmap;
167
168 platform_set_drvdata(pdev, sysmgr);
169
170 return 0;
171 }
172
173 static const struct of_device_id altr_sysmgr_of_match[] = {
174 { .compatible = "altr,sys-mgr" },
175 { .compatible = "altr,sys-mgr-s10" },
176 {},
177 };
178 MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);
179
180 static struct platform_driver altr_sysmgr_driver = {
181 .probe = sysmgr_probe,
182 .driver = {
183 .name = "altr,system_manager",
184 .of_match_table = altr_sysmgr_of_match,
185 },
186 };
187
altr_sysmgr_init(void)188 static int __init altr_sysmgr_init(void)
189 {
190 return platform_driver_register(&altr_sysmgr_driver);
191 }
192 core_initcall(altr_sysmgr_init);
193
altr_sysmgr_exit(void)194 static void __exit altr_sysmgr_exit(void)
195 {
196 platform_driver_unregister(&altr_sysmgr_driver);
197 }
198 module_exit(altr_sysmgr_exit);
199
200 MODULE_AUTHOR("Thor Thayer <>");
201 MODULE_DESCRIPTION("SOCFPGA System Manager driver");
202