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 struct pch_fivr_resp { 13 u64 status; 14 u64 result; 15 }; 16 17 static 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 43 release_buffer: 44 kfree(buffer.pointer); 45 return ret; 46 } 47 48 /* 49 * Presentation of attributes which are defined for INT1045 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) \ 57 static 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) \ 73 static 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 91 PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0) 92 PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1) 93 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0) 94 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1) 95 96 static DEVICE_ATTR_RW(freq_mhz_low_clock); 97 static DEVICE_ATTR_RW(freq_mhz_high_clock); 98 99 static struct attribute *fivr_attrs[] = { 100 &dev_attr_freq_mhz_low_clock.attr, 101 &dev_attr_freq_mhz_high_clock.attr, 102 NULL 103 }; 104 105 static const struct attribute_group pch_fivr_attribute_group = { 106 .attrs = fivr_attrs, 107 .name = "pch_fivr_switch_frequency" 108 }; 109 110 static int pch_fivr_add(struct platform_device *pdev) 111 { 112 struct acpi_device *acpi_dev; 113 unsigned long long ptype; 114 acpi_status status; 115 int result; 116 117 acpi_dev = ACPI_COMPANION(&(pdev->dev)); 118 if (!acpi_dev) 119 return -ENODEV; 120 121 status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype); 122 if (ACPI_FAILURE(status) || ptype != 0x05) 123 return -ENODEV; 124 125 result = sysfs_create_group(&pdev->dev.kobj, 126 &pch_fivr_attribute_group); 127 if (result) 128 return result; 129 130 platform_set_drvdata(pdev, acpi_dev); 131 132 return 0; 133 } 134 135 static int pch_fivr_remove(struct platform_device *pdev) 136 { 137 sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group); 138 139 return 0; 140 } 141 142 static const struct acpi_device_id pch_fivr_device_ids[] = { 143 {"INTC1045", 0}, 144 {"INTC1049", 0}, 145 {"", 0}, 146 }; 147 MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids); 148 149 static struct platform_driver pch_fivr_driver = { 150 .probe = pch_fivr_add, 151 .remove = pch_fivr_remove, 152 .driver = { 153 .name = "dptf_pch_fivr", 154 .acpi_match_table = pch_fivr_device_ids, 155 }, 156 }; 157 158 module_platform_driver(pch_fivr_driver); 159 160 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); 161 MODULE_LICENSE("GPL v2"); 162 MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver"); 163