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
21 struct smpro_misc {
22 struct regmap *regmap;
23 };
24
boot_progress_show(struct device * dev,struct device_attribute * da,char * buf)25 static 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, ®);
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, ®_lo);
53 if (!ret)
54 ret = regmap_read(misc->regmap, BOOTSTAGE_HI, ®);
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
72 static DEVICE_ATTR_RO(boot_progress);
73
soc_power_limit_show(struct device * dev,struct device_attribute * da,char * buf)74 static 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
soc_power_limit_store(struct device * dev,struct device_attribute * da,const char * buf,size_t count)87 static 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
105 static DEVICE_ATTR_RW(soc_power_limit);
106
107 static struct attribute *smpro_misc_attrs[] = {
108 &dev_attr_boot_progress.attr,
109 &dev_attr_soc_power_limit.attr,
110 NULL
111 };
112
113 ATTRIBUTE_GROUPS(smpro_misc);
114
smpro_misc_probe(struct platform_device * pdev)115 static 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
132 static 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
140 module_platform_driver(smpro_misc_driver);
141
142 MODULE_AUTHOR("Tung Nguyen <tungnguyen@os.amperecomputing.com>");
143 MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>");
144 MODULE_DESCRIPTION("Ampere Altra SMpro Misc driver");
145 MODULE_LICENSE("GPL");
146