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 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) \ 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_SHOW(ssc_clock_info, GEMI) 94 PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS) 95 PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS) 96 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0) 97 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1) 98 99 static DEVICE_ATTR_RW(freq_mhz_low_clock); 100 static DEVICE_ATTR_RW(freq_mhz_high_clock); 101 static DEVICE_ATTR_RO(ssc_clock_info); 102 static DEVICE_ATTR_RO(fivr_switching_freq_mhz); 103 static DEVICE_ATTR_RO(fivr_switching_fault_status); 104 105 static 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 }; 113 114 static const struct attribute_group pch_fivr_attribute_group = { 115 .attrs = fivr_attrs, 116 .name = "pch_fivr_switch_frequency" 117 }; 118 119 static 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 } 143 144 static int pch_fivr_remove(struct platform_device *pdev) 145 { 146 sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group); 147 148 return 0; 149 } 150 151 static const struct acpi_device_id pch_fivr_device_ids[] = { 152 {"INTC1045", 0}, 153 {"INTC1049", 0}, 154 {"INTC1064", 0}, 155 {"INTC10A3", 0}, 156 {"", 0}, 157 }; 158 MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids); 159 160 static 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 }; 168 169 module_platform_driver(pch_fivr_driver); 170 171 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); 172 MODULE_LICENSE("GPL v2"); 173 MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver"); 174