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144 lines · 3.1 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Ampere Computing SoC's SMpro Misc Driver
4 *
5 * Copyright (c) 2022, Ampere Computing LLC
6 */
7#include <linux/module.h>
8#include <linux/platform_device.h>
9#include <linux/regmap.h>
10
11/* Boot Stage/Progress Registers */
12#define BOOTSTAGE 0xB0
13#define BOOTSTAGE_LO 0xB1
14#define CUR_BOOTSTAGE 0xB2
15#define BOOTSTAGE_HI 0xB3
16
17/* SOC State Registers */
18#define SOC_POWER_LIMIT 0xE5
19
20struct smpro_misc {
21 struct regmap *regmap;
22};
23
24static ssize_t boot_progress_show(struct device *dev, struct device_attribute *da, char *buf)
25{
26 struct smpro_misc *misc = dev_get_drvdata(dev);
27 u16 boot_progress[3] = { 0 };
28 u32 bootstage;
29 u8 boot_stage;
30 u8 cur_stage;
31 u32 reg_lo;
32 u32 reg;
33 int ret;
34
35 /* Read current boot stage */
36 ret = regmap_read(misc->regmap, CUR_BOOTSTAGE, &reg);
37 if (ret)
38 return ret;
39
40 cur_stage = reg & 0xff;
41
42 ret = regmap_read(misc->regmap, BOOTSTAGE, &bootstage);
43 if (ret)
44 return ret;
45
46 boot_stage = (bootstage >> 8) & 0xff;
47
48 if (boot_stage > cur_stage)
49 return -EINVAL;
50
51 ret = regmap_read(misc->regmap, BOOTSTAGE_LO, &reg_lo);
52 if (!ret)
53 ret = regmap_read(misc->regmap, BOOTSTAGE_HI, &reg);
54 if (ret)
55 return ret;
56
57 /* Firmware to report new boot stage next time */
58 if (boot_stage < cur_stage) {
59 ret = regmap_write(misc->regmap, BOOTSTAGE, ((bootstage & 0xff00) | 0x1));
60 if (ret)
61 return ret;
62 }
63
64 boot_progress[0] = bootstage;
65 boot_progress[1] = swab16(reg);
66 boot_progress[2] = swab16(reg_lo);
67
68 return sysfs_emit(buf, "%*phN\n", (int)sizeof(boot_progress), boot_progress);
69}
70
71static DEVICE_ATTR_RO(boot_progress);
72
73static ssize_t soc_power_limit_show(struct device *dev, struct device_attribute *da, char *buf)
74{
75 struct smpro_misc *misc = dev_get_drvdata(dev);
76 unsigned int value;
77 int ret;
78
79 ret = regmap_read(misc->regmap, SOC_POWER_LIMIT, &value);
80 if (ret)
81 return ret;
82
83 return sysfs_emit(buf, "%d\n", value);
84}
85
86static ssize_t soc_power_limit_store(struct device *dev, struct device_attribute *da,
87 const char *buf, size_t count)
88{
89 struct smpro_misc *misc = dev_get_drvdata(dev);
90 unsigned long val;
91 s32 ret;
92
93 ret = kstrtoul(buf, 0, &val);
94 if (ret)
95 return ret;
96
97 ret = regmap_write(misc->regmap, SOC_POWER_LIMIT, (unsigned int)val);
98 if (ret)
99 return -EPROTO;
100
101 return count;
102}
103
104static DEVICE_ATTR_RW(soc_power_limit);
105
106static struct attribute *smpro_misc_attrs[] = {
107 &dev_attr_boot_progress.attr,
108 &dev_attr_soc_power_limit.attr,
109 NULL
110};
111
112ATTRIBUTE_GROUPS(smpro_misc);
113
114static int smpro_misc_probe(struct platform_device *pdev)
115{
116 struct smpro_misc *misc;
117
118 misc = devm_kzalloc(&pdev->dev, sizeof(struct smpro_misc), GFP_KERNEL);
119 if (!misc)
120 return -ENOMEM;
121
122 platform_set_drvdata(pdev, misc);
123
124 misc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
125 if (!misc->regmap)
126 return -ENODEV;
127
128 return 0;
129}
130
131static struct platform_driver smpro_misc_driver = {
132 .probe = smpro_misc_probe,
133 .driver = {
134 .name = "smpro-misc",
135 .dev_groups = smpro_misc_groups,
136 },
137};
138
139module_platform_driver(smpro_misc_driver);
140
141MODULE_AUTHOR("Tung Nguyen <[email protected]>");
142MODULE_AUTHOR("Quan Nguyen <[email protected]>");
143MODULE_DESCRIPTION("Ampere Altra SMpro Misc driver");
144MODULE_LICENSE("GPL");