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/mod_devicetable.h>
8#include <linux/module.h>
9#include <linux/platform_device.h>
10#include <linux/regmap.h>
11
12/* Boot Stage/Progress Registers */
13#define BOOTSTAGE	0xB0
14#define BOOTSTAGE_LO	0xB1
15#define CUR_BOOTSTAGE	0xB2
16#define BOOTSTAGE_HI	0xB3
17
18/* SOC State Registers */
19#define SOC_POWER_LIMIT		0xE5
20
21struct smpro_misc {
22	struct regmap *regmap;
23};
24
25static ssize_t boot_progress_show(struct device *dev, struct device_attribute *da, char *buf)
26{
27	struct smpro_misc *misc = dev_get_drvdata(dev);
28	u16 boot_progress[3] = { 0 };
29	u32 bootstage;
30	u8 boot_stage;
31	u8 cur_stage;
32	u32 reg_lo;
33	u32 reg;
34	int ret;
35
36	/* Read current boot stage */
37	ret = regmap_read(misc->regmap, CUR_BOOTSTAGE, &reg);
38	if (ret)
39		return ret;
40
41	cur_stage = reg & 0xff;
42
43	ret = regmap_read(misc->regmap, BOOTSTAGE, &bootstage);
44	if (ret)
45		return ret;
46
47	boot_stage = (bootstage >> 8) & 0xff;
48
49	if (boot_stage > cur_stage)
50		return -EINVAL;
51
52	ret = regmap_read(misc->regmap,	BOOTSTAGE_LO, &reg_lo);
53	if (!ret)
54		ret = regmap_read(misc->regmap, BOOTSTAGE_HI, &reg);
55	if (ret)
56		return ret;
57
58	/* Firmware to report new boot stage next time */
59	if (boot_stage < cur_stage) {
60		ret = regmap_write(misc->regmap, BOOTSTAGE, ((bootstage & 0xff00) | 0x1));
61		if (ret)
62			return ret;
63	}
64
65	boot_progress[0] = bootstage;
66	boot_progress[1] = swab16(reg);
67	boot_progress[2] = swab16(reg_lo);
68
69	return sysfs_emit(buf, "%*phN\n", (int)sizeof(boot_progress), boot_progress);
70}
71
72static DEVICE_ATTR_RO(boot_progress);
73
74static ssize_t soc_power_limit_show(struct device *dev, struct device_attribute *da, char *buf)
75{
76	struct smpro_misc *misc = dev_get_drvdata(dev);
77	unsigned int value;
78	int ret;
79
80	ret = regmap_read(misc->regmap, SOC_POWER_LIMIT, &value);
81	if (ret)
82		return ret;
83
84	return sysfs_emit(buf, "%d\n", value);
85}
86
87static ssize_t soc_power_limit_store(struct device *dev, struct device_attribute *da,
88				     const char *buf, size_t count)
89{
90	struct smpro_misc *misc = dev_get_drvdata(dev);
91	unsigned long val;
92	s32 ret;
93
94	ret = kstrtoul(buf, 0, &val);
95	if (ret)
96		return ret;
97
98	ret = regmap_write(misc->regmap, SOC_POWER_LIMIT, (unsigned int)val);
99	if (ret)
100		return -EPROTO;
101
102	return count;
103}
104
105static DEVICE_ATTR_RW(soc_power_limit);
106
107static struct attribute *smpro_misc_attrs[] = {
108	&dev_attr_boot_progress.attr,
109	&dev_attr_soc_power_limit.attr,
110	NULL
111};
112
113ATTRIBUTE_GROUPS(smpro_misc);
114
115static int smpro_misc_probe(struct platform_device *pdev)
116{
117	struct smpro_misc *misc;
118
119	misc = devm_kzalloc(&pdev->dev, sizeof(struct smpro_misc), GFP_KERNEL);
120	if (!misc)
121		return -ENOMEM;
122
123	platform_set_drvdata(pdev, misc);
124
125	misc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
126	if (!misc->regmap)
127		return -ENODEV;
128
129	return 0;
130}
131
132static struct platform_driver smpro_misc_driver = {
133	.probe		= smpro_misc_probe,
134	.driver = {
135		.name	= "smpro-misc",
136		.dev_groups = smpro_misc_groups,
137	},
138};
139
140module_platform_driver(smpro_misc_driver);
141
142MODULE_AUTHOR("Tung Nguyen <tungnguyen@os.amperecomputing.com>");
143MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>");
144MODULE_DESCRIPTION("Ampere Altra SMpro Misc driver");
145MODULE_LICENSE("GPL");
146