summaryrefslogtreecommitdiff
path: root/drivers/mfd/altera-sysmgr.c
blob: 193a96c8b1eab9b1c4cf30307dc990f4b242c161 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 2018-2019, Intel Corporation.
 *  Copyright (C) 2012 Freescale Semiconductor, Inc.
 *  Copyright (C) 2012 Linaro Ltd.
 *
 *  Based on syscon driver.
 */

#include <linux/arm-smccc.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/mfd/altera-sysmgr.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>
#include <linux/slab.h>

/**
 * struct altr_sysmgr - Altera SOCFPGA System Manager
 * @regmap: the regmap used for System Manager accesses.
 */
struct altr_sysmgr {
	struct regmap   *regmap;
};

static struct platform_driver altr_sysmgr_driver;

/**
 * s10_protected_reg_write
 * Write to a protected SMC register.
 * @base: Base address of System Manager
 * @reg:  Address offset of register
 * @val:  Value to write
 * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
 *	   INTEL_SIP_SMC_REG_ERROR on error
 *	   INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
 */
static int s10_protected_reg_write(void *base,
				   unsigned int reg, unsigned int val)
{
	struct arm_smccc_res result;
	unsigned long sysmgr_base = (unsigned long)base;

	arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg,
		      val, 0, 0, 0, 0, 0, &result);

	return (int)result.a0;
}

/**
 * s10_protected_reg_read
 * Read the status of a protected SMC register
 * @base: Base address of System Manager.
 * @reg:  Address of register
 * @val:  Value read.
 * Return: INTEL_SIP_SMC_STATUS_OK (0) on success
 *	   INTEL_SIP_SMC_REG_ERROR on error
 *	   INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
 */
static int s10_protected_reg_read(void *base,
				  unsigned int reg, unsigned int *val)
{
	struct arm_smccc_res result;
	unsigned long sysmgr_base = (unsigned long)base;

	arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg,
		      0, 0, 0, 0, 0, 0, &result);

	*val = (unsigned int)result.a1;

	return (int)result.a0;
}

static struct regmap_config altr_sysmgr_regmap_cfg = {
	.name = "altr_sysmgr",
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.fast_io = true,
	.use_single_read = true,
	.use_single_write = true,
};

/**
 * altr_sysmgr_regmap_lookup_by_phandle
 * Find the sysmgr previous configured in probe() and return regmap property.
 * Return: regmap if found or error if not found.
 *
 * @np: Pointer to device's Device Tree node
 * @property: Device Tree property name which references the sysmgr
 */
struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
						    const char *property)
{
	struct device *dev;
	struct altr_sysmgr *sysmgr;
	struct device_node *sysmgr_np;

	if (property)
		sysmgr_np = of_parse_phandle(np, property, 0);
	else
		sysmgr_np = np;

	if (!sysmgr_np)
		return ERR_PTR(-ENODEV);

	dev = driver_find_device_by_of_node(&altr_sysmgr_driver.driver,
					    (void *)sysmgr_np);
	of_node_put(sysmgr_np);
	if (!dev)
		return ERR_PTR(-EPROBE_DEFER);

	sysmgr = dev_get_drvdata(dev);

	return sysmgr->regmap;
}
EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);

static int sysmgr_probe(struct platform_device *pdev)
{
	struct altr_sysmgr *sysmgr;
	struct regmap *regmap;
	struct resource *res;
	struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	void __iomem *base;

	sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
	if (!sysmgr)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENOENT;

	sysmgr_config.max_register = resource_size(res) -
				     sysmgr_config.reg_stride;
	if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
		sysmgr_config.reg_read = s10_protected_reg_read;
		sysmgr_config.reg_write = s10_protected_reg_write;

		/* Need physical address for SMCC call */
		regmap = devm_regmap_init(dev, NULL, (void *)res->start,
					  &sysmgr_config);
	} else {
		base = devm_ioremap(dev, res->start, resource_size(res));
		if (!base)
			return -ENOMEM;

		sysmgr_config.max_register = resource_size(res) - 3;
		regmap = devm_regmap_init_mmio(dev, base, &sysmgr_config);
	}

	if (IS_ERR(regmap)) {
		pr_err("regmap init failed\n");
		return PTR_ERR(regmap);
	}

	sysmgr->regmap = regmap;

	platform_set_drvdata(pdev, sysmgr);

	return 0;
}

static const struct of_device_id altr_sysmgr_of_match[] = {
	{ .compatible = "altr,sys-mgr" },
	{ .compatible = "altr,sys-mgr-s10" },
	{},
};
MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);

static struct platform_driver altr_sysmgr_driver = {
	.probe =  sysmgr_probe,
	.driver = {
		.name = "altr,system_manager",
		.of_match_table = altr_sysmgr_of_match,
	},
};

static int __init altr_sysmgr_init(void)
{
	return platform_driver_register(&altr_sysmgr_driver);
}
core_initcall(altr_sysmgr_init);

static void __exit altr_sysmgr_exit(void)
{
	platform_driver_unregister(&altr_sysmgr_driver);
}
module_exit(altr_sysmgr_exit);

MODULE_AUTHOR("Thor Thayer <>");
MODULE_DESCRIPTION("SOCFPGA System Manager driver");
MODULE_LICENSE("GPL v2");