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| 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"); |
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