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 /*
  13  * Presentation of attributes which are defined for INT1045
  14  * They are:
  15  * freq_mhz_low_clock : Set PCH FIVR switching freq for
  16  *                      FIVR clock 19.2MHz and 24MHz
  17  * freq_mhz_high_clock : Set PCH FIVR switching freq for
  18  *                      FIVR clock 38.4MHz
  19  */
  20 #define PCH_FIVR_SHOW(name, method) \
  21 static ssize_t name##_show(struct device *dev,\
  22                            struct device_attribute *attr,\
  23                            char *buf)\
  24 {\
  25         struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
  26         unsigned long long val;\
  27         acpi_status status;\
  28 \
  29         status = acpi_evaluate_integer(acpi_dev->handle, #method,\
  30                                        NULL, &val);\
  31         if (ACPI_SUCCESS(status))\
  32                 return sprintf(buf, "%d\n", (int)val);\
  33         else\
  34                 return -EINVAL;\
  35 }
  36
  37 #define PCH_FIVR_STORE(name, method) \
  38 static ssize_t name##_store(struct device *dev,\
  39                             struct device_attribute *attr,\
  40                             const char *buf, size_t count)\
  41 {\
  42         struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
  43         acpi_status status;\
  44         u32 val;\
  45 \
  46         if (kstrtouint(buf, 0, &val) < 0)\
  47                 return -EINVAL;\
  48 \
  49         status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\
  50         if (ACPI_SUCCESS(status))\
  51                 return count;\
  52 \
  53         return -EINVAL;\
  54 }
  55
  56 PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
  57 PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
  58 PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
  59 PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
  60
  61 static DEVICE_ATTR_RW(freq_mhz_low_clock);
  62 static DEVICE_ATTR_RW(freq_mhz_high_clock);
  63
  64 static struct attribute *fivr_attrs[] = {
  65         &dev_attr_freq_mhz_low_clock.attr,
  66         &dev_attr_freq_mhz_high_clock.attr,
  67         NULL
  68 };
  69
  70 static const struct attribute_group pch_fivr_attribute_group = {
  71         .attrs = fivr_attrs,
  72         .name = "pch_fivr_switch_frequency"
  73 };
  74
  75 static int pch_fivr_add(struct platform_device *pdev)
  76 {
  77         struct acpi_device *acpi_dev;
  78         unsigned long long ptype;
  79         acpi_status status;
  80         int result;
  81
  82         acpi_dev = ACPI_COMPANION(&(pdev->dev));
  83         if (!acpi_dev)
  84                 return -ENODEV;
  85
  86         status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype);
  87         if (ACPI_FAILURE(status) || ptype != 0x05)
  88                 return -ENODEV;
  89
  90         result = sysfs_create_group(&pdev->dev.kobj,
  91                                     &pch_fivr_attribute_group);
  92         if (result)
  93                 return result;
  94
  95         platform_set_drvdata(pdev, acpi_dev);
  96
  97         return 0;
  98 }
  99
 100 static int pch_fivr_remove(struct platform_device *pdev)
 101 {
 102         sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group);
 103
 104         return 0;
 105 }
 106
 107 static const struct acpi_device_id pch_fivr_device_ids[] = {
 108         {"INTC1045", 0},
 109         {"", 0},
 110 };
 111 MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids);
 112
 113 static struct platform_driver pch_fivr_driver = {
 114         .probe = pch_fivr_add,
 115         .remove = pch_fivr_remove,
 116         .driver = {
 117                 .name = "DPTF PCH FIVR",
 118                 .acpi_match_table = pch_fivr_device_ids,
 119         },
 120 };
 121
 122 module_platform_driver(pch_fivr_driver);
 123
 124 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 125 MODULE_LICENSE("GPL v2");
 126 MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver");