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 */
25struct altr_sysmgr {
26	struct regmap   *regmap;
27};
28
29static 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 */
41static 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 */
63static 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
77static 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 */
95struct 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}
122EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
123
124static 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
173static const struct of_device_id altr_sysmgr_of_match[] = {
174	{ .compatible = "altr,sys-mgr" },
175	{ .compatible = "altr,sys-mgr-s10" },
176	{},
177};
178MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);
179
180static 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
188static int __init altr_sysmgr_init(void)
189{
190	return platform_driver_register(&altr_sysmgr_driver);
191}
192core_initcall(altr_sysmgr_init);
193
194static void __exit altr_sysmgr_exit(void)
195{
196	platform_driver_unregister(&altr_sysmgr_driver);
197}
198module_exit(altr_sysmgr_exit);
199
200MODULE_AUTHOR("Thor Thayer <>");
201MODULE_DESCRIPTION("SOCFPGA System Manager driver");
202