dptf_pch_fivr.c

  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
 12struct pch_fivr_resp {
 13	u64 status;
 14	u64 result;
 15};
 16
 17static int pch_fivr_read(acpi_handle handle, char *method, struct pch_fivr_resp *fivr_resp)
 18{
 19	struct acpi_buffer resp = { sizeof(struct pch_fivr_resp), fivr_resp};
 20	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 21	struct acpi_buffer format = { sizeof("NN"), "NN" };
 22	union acpi_object *obj;
 23	acpi_status status;
 24	int ret = -EFAULT;
 25
 26	status = acpi_evaluate_object(handle, method, NULL, &buffer);
 27	if (ACPI_FAILURE(status))
 28		return ret;
 29
 30	obj = buffer.pointer;
 31	if (!obj || obj->type != ACPI_TYPE_PACKAGE)
 32		goto release_buffer;
 33
 34	status = acpi_extract_package(obj, &format, &resp);
 35	if (ACPI_FAILURE(status))
 36		goto release_buffer;
 37
 38	if (fivr_resp->status)
 39		goto release_buffer;
 40
 41	ret = 0;
 42
 43release_buffer:
 44	ACPI_FREE(buffer.pointer);
 45	return ret;
 46}
 47
 48/*
 49 * Presentation of attributes which are defined for INTC10xx
 50 * They are:
 51 * freq_mhz_low_clock : Set PCH FIVR switching freq for
 52 *			FIVR clock 19.2MHz and 24MHz
 53 * freq_mhz_high_clock : Set PCH FIVR switching freq for
 54 *			FIVR clock 38.4MHz
 55 */
 56#define PCH_FIVR_SHOW(name, method) \
 57static ssize_t name##_show(struct device *dev,\
 58			   struct device_attribute *attr,\
 59			   char *buf)\
 60{\
 61	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
 62	struct pch_fivr_resp fivr_resp;\
 63	int status;\
 64\
 65	status = pch_fivr_read(acpi_dev->handle, #method, &fivr_resp);\
 66	if (status)\
 67		return status;\
 68\
 69	return sprintf(buf, "%llu\n", fivr_resp.result);\
 70}
 71
 72#define PCH_FIVR_STORE(name, method) \
 73static ssize_t name##_store(struct device *dev,\
 74			    struct device_attribute *attr,\
 75			    const char *buf, size_t count)\
 76{\
 77	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
 78	acpi_status status;\
 79	u32 val;\
 80\
 81	if (kstrtouint(buf, 0, &val) < 0)\
 82		return -EINVAL;\
 83\
 84	status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\
 85	if (ACPI_SUCCESS(status))\
 86		return count;\
 87\
 88	return -EINVAL;\
 89}
 90
 91PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
 92PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
 93PCH_FIVR_SHOW(ssc_clock_info, GEMI)
 94PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
 95PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
 96PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
 97PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
 98
 99static DEVICE_ATTR_RW(freq_mhz_low_clock);
100static DEVICE_ATTR_RW(freq_mhz_high_clock);
101static DEVICE_ATTR_RO(ssc_clock_info);
102static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
103static DEVICE_ATTR_RO(fivr_switching_fault_status);
104
105static struct attribute *fivr_attrs[] = {
106	&dev_attr_freq_mhz_low_clock.attr,
107	&dev_attr_freq_mhz_high_clock.attr,
108	&dev_attr_ssc_clock_info.attr,
109	&dev_attr_fivr_switching_freq_mhz.attr,
110	&dev_attr_fivr_switching_fault_status.attr,
111	NULL
112};
113
114static const struct attribute_group pch_fivr_attribute_group = {
115	.attrs = fivr_attrs,
116	.name = "pch_fivr_switch_frequency"
117};
118
119static int pch_fivr_add(struct platform_device *pdev)
120{
121	struct acpi_device *acpi_dev;
122	unsigned long long ptype;
123	acpi_status status;
124	int result;
125
126	acpi_dev = ACPI_COMPANION(&(pdev->dev));
127	if (!acpi_dev)
128		return -ENODEV;
129
130	status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype);
131	if (ACPI_FAILURE(status) || ptype != 0x05)
132		return -ENODEV;
133
134	result = sysfs_create_group(&pdev->dev.kobj,
135				    &pch_fivr_attribute_group);
136	if (result)
137		return result;
138
139	platform_set_drvdata(pdev, acpi_dev);
140
141	return 0;
142}
143
144static void pch_fivr_remove(struct platform_device *pdev)
145{
146	sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group);
147}
148
149static const struct acpi_device_id pch_fivr_device_ids[] = {
150	{"INTC1045", 0},
151	{"INTC1049", 0},
152	{"INTC1064", 0},
153	{"INTC106B", 0},
154	{"INTC10A3", 0},
155	{"INTC10D7", 0},
156	{"", 0},
157};
158MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids);
159
160static struct platform_driver pch_fivr_driver = {
161	.probe = pch_fivr_add,
162	.remove = pch_fivr_remove,
163	.driver = {
164		.name = "dptf_pch_fivr",
165		.acpi_match_table = pch_fivr_device_ids,
166	},
167};
168
169module_platform_driver(pch_fivr_driver);
170
171MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
172MODULE_LICENSE("GPL v2");
173MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver");