acpi/dptf/dptf_pch_fivr.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * dptf_pch_fivr:  DPTF PCH FIVR Participant driver
0004  * Copyright (c) 2020, Intel Corporation.
0005  */
0006
0007 #include <linux/acpi.h>
0008 #include <linux/kernel.h>
0009 #include <linux/module.h>
0010 #include <linux/platform_device.h>
0011
0012 struct pch_fivr_resp {
0013     u64 status;
0014     u64 result;
0015 };
0016
0017 static int pch_fivr_read(acpi_handle handle, char *method, struct pch_fivr_resp *fivr_resp)
0018 {
0019     struct acpi_buffer resp = { sizeof(struct pch_fivr_resp), fivr_resp};
0020     struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
0021     struct acpi_buffer format = { sizeof("NN"), "NN" };
0022     union acpi_object *obj;
0023     acpi_status status;
0024     int ret = -EFAULT;
0025
0026     status = acpi_evaluate_object(handle, method, NULL, &buffer);
0027     if (ACPI_FAILURE(status))
0028         return ret;
0029
0030     obj = buffer.pointer;
0031     if (!obj || obj->type != ACPI_TYPE_PACKAGE)
0032         goto release_buffer;
0033
0034     status = acpi_extract_package(obj, &format, &resp);
0035     if (ACPI_FAILURE(status))
0036         goto release_buffer;
0037
0038     if (fivr_resp->status)
0039         goto release_buffer;
0040
0041     ret = 0;
0042
0043 release_buffer:
0044     kfree(buffer.pointer);
0045     return ret;
0046 }
0047
0048 /*
0049  * Presentation of attributes which are defined for INTC10xx
0050  * They are:
0051  * freq_mhz_low_clock : Set PCH FIVR switching freq for
0052  *          FIVR clock 19.2MHz and 24MHz
0053  * freq_mhz_high_clock : Set PCH FIVR switching freq for
0054  *          FIVR clock 38.4MHz
0055  */
0056 #define PCH_FIVR_SHOW(name, method) \
0057 static ssize_t name##_show(struct device *dev,\
0058                struct device_attribute *attr,\
0059                char *buf)\
0060 {\
0061     struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
0062     struct pch_fivr_resp fivr_resp;\
0063     int status;\
0064 \
0065     status = pch_fivr_read(acpi_dev->handle, #method, &fivr_resp);\
0066     if (status)\
0067         return status;\
0068 \
0069     return sprintf(buf, "%llu\n", fivr_resp.result);\
0070 }
0071
0072 #define PCH_FIVR_STORE(name, method) \
0073 static ssize_t name##_store(struct device *dev,\
0074                 struct device_attribute *attr,\
0075                 const char *buf, size_t count)\
0076 {\
0077     struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
0078     acpi_status status;\
0079     u32 val;\
0080 \
0081     if (kstrtouint(buf, 0, &val) < 0)\
0082         return -EINVAL;\
0083 \
0084     status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\
0085     if (ACPI_SUCCESS(status))\
0086         return count;\
0087 \
0088     return -EINVAL;\
0089 }
0090
0091 PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
0092 PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
0093 PCH_FIVR_SHOW(ssc_clock_info, GEMI)
0094 PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
0095 PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
0096 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
0097 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
0098
0099 static DEVICE_ATTR_RW(freq_mhz_low_clock);
0100 static DEVICE_ATTR_RW(freq_mhz_high_clock);
0101 static DEVICE_ATTR_RO(ssc_clock_info);
0102 static DEVICE_ATTR_RO(fivr_switching_freq_mhz);
0103 static DEVICE_ATTR_RO(fivr_switching_fault_status);
0104
0105 static struct attribute *fivr_attrs[] = {
0106     &dev_attr_freq_mhz_low_clock.attr,
0107     &dev_attr_freq_mhz_high_clock.attr,
0108     &dev_attr_ssc_clock_info.attr,
0109     &dev_attr_fivr_switching_freq_mhz.attr,
0110     &dev_attr_fivr_switching_fault_status.attr,
0111     NULL
0112 };
0113
0114 static const struct attribute_group pch_fivr_attribute_group = {
0115     .attrs = fivr_attrs,
0116     .name = "pch_fivr_switch_frequency"
0117 };
0118
0119 static int pch_fivr_add(struct platform_device *pdev)
0120 {
0121     struct acpi_device *acpi_dev;
0122     unsigned long long ptype;
0123     acpi_status status;
0124     int result;
0125
0126     acpi_dev = ACPI_COMPANION(&(pdev->dev));
0127     if (!acpi_dev)
0128         return -ENODEV;
0129
0130     status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype);
0131     if (ACPI_FAILURE(status) || ptype != 0x05)
0132         return -ENODEV;
0133
0134     result = sysfs_create_group(&pdev->dev.kobj,
0135                     &pch_fivr_attribute_group);
0136     if (result)
0137         return result;
0138
0139     platform_set_drvdata(pdev, acpi_dev);
0140
0141     return 0;
0142 }
0143
0144 static int pch_fivr_remove(struct platform_device *pdev)
0145 {
0146     sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group);
0147
0148     return 0;
0149 }
0150
0151 static const struct acpi_device_id pch_fivr_device_ids[] = {
0152     {"INTC1045", 0},
0153     {"INTC1049", 0},
0154     {"INTC1064", 0},
0155     {"INTC10A3", 0},
0156     {"", 0},
0157 };
0158 MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids);
0159
0160 static struct platform_driver pch_fivr_driver = {
0161     .probe = pch_fivr_add,
0162     .remove = pch_fivr_remove,
0163     .driver = {
0164         .name = "dptf_pch_fivr",
0165         .acpi_match_table = pch_fivr_device_ids,
0166     },
0167 };
0168
0169 module_platform_driver(pch_fivr_driver);
0170
0171 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
0172 MODULE_LICENSE("GPL v2");
0173 MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver");