drivers/acpi/dptf/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
  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_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         {"", 0},
 155 };
 156 MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids);
 157
 158 static struct platform_driver pch_fivr_driver = {
 159         .probe = pch_fivr_add,
 160         .remove = pch_fivr_remove,
 161         .driver = {
 162                 .name = "dptf_pch_fivr",
 163                 .acpi_match_table = pch_fivr_device_ids,
 164         },
 165 };
 166
 167 module_platform_driver(pch_fivr_driver);
 168
 169 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 170 MODULE_LICENSE("GPL v2");
 171 MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver");