1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * dptf_pch_fivr:  DPTF PCH FIVR Participant driver
4  * Copyright (c) 2020, Intel Corporation.
5  */
6 
7 #include <linux/acpi.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 
12 /*
13  * Presentation of attributes which are defined for INT1045
14  * They are:
15  * freq_mhz_low_clock : Set PCH FIVR switching freq for
16  *			FIVR clock 19.2MHz and 24MHz
17  * freq_mhz_high_clock : Set PCH FIVR switching freq for
18  *			FIVR clock 38.4MHz
19  */
20 #define PCH_FIVR_SHOW(name, method) \
21 static ssize_t name##_show(struct device *dev,\
22 			   struct device_attribute *attr,\
23 			   char *buf)\
24 {\
25 	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
26 	unsigned long long val;\
27 	acpi_status status;\
28 \
29 	status = acpi_evaluate_integer(acpi_dev->handle, #method,\
30 				       NULL, &val);\
31 	if (ACPI_SUCCESS(status))\
32 		return sprintf(buf, "%d\n", (int)val);\
33 	else\
34 		return -EINVAL;\
35 }
36 
37 #define PCH_FIVR_STORE(name, method) \
38 static ssize_t name##_store(struct device *dev,\
39 			    struct device_attribute *attr,\
40 			    const char *buf, size_t count)\
41 {\
42 	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
43 	acpi_status status;\
44 	u32 val;\
45 \
46 	if (kstrtouint(buf, 0, &val) < 0)\
47 		return -EINVAL;\
48 \
49 	status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\
50 	if (ACPI_SUCCESS(status))\
51 		return count;\
52 \
53 	return -EINVAL;\
54 }
55 
56 PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
57 PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
58 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
59 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
60 
61 static DEVICE_ATTR_RW(freq_mhz_low_clock);
62 static DEVICE_ATTR_RW(freq_mhz_high_clock);
63 
64 static struct attribute *fivr_attrs[] = {
65 	&dev_attr_freq_mhz_low_clock.attr,
66 	&dev_attr_freq_mhz_high_clock.attr,
67 	NULL
68 };
69 
70 static const struct attribute_group pch_fivr_attribute_group = {
71 	.attrs = fivr_attrs,
72 	.name = "pch_fivr_switch_frequency"
73 };
74 
75 static int pch_fivr_add(struct platform_device *pdev)
76 {
77 	struct acpi_device *acpi_dev;
78 	unsigned long long ptype;
79 	acpi_status status;
80 	int result;
81 
82 	acpi_dev = ACPI_COMPANION(&(pdev->dev));
83 	if (!acpi_dev)
84 		return -ENODEV;
85 
86 	status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype);
87 	if (ACPI_FAILURE(status) || ptype != 0x05)
88 		return -ENODEV;
89 
90 	result = sysfs_create_group(&pdev->dev.kobj,
91 				    &pch_fivr_attribute_group);
92 	if (result)
93 		return result;
94 
95 	platform_set_drvdata(pdev, acpi_dev);
96 
97 	return 0;
98 }
99 
100 static int pch_fivr_remove(struct platform_device *pdev)
101 {
102 	sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group);
103 
104 	return 0;
105 }
106 
107 static const struct acpi_device_id pch_fivr_device_ids[] = {
108 	{"INTC1045", 0},
109 	{"INTC1049", 0},
110 	{"", 0},
111 };
112 MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids);
113 
114 static struct platform_driver pch_fivr_driver = {
115 	.probe = pch_fivr_add,
116 	.remove = pch_fivr_remove,
117 	.driver = {
118 		.name = "dptf_pch_fivr",
119 		.acpi_match_table = pch_fivr_device_ids,
120 	},
121 };
122 
123 module_platform_driver(pch_fivr_driver);
124 
125 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
126 MODULE_LICENSE("GPL v2");
127 MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver");
128