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41a8457f3f
The current assumption that methods to read PCH FIVR attributes will
return integer, is not correct. There is no good way to return integer
as negative numbers are also valid.
These read methods return a package of integers. The first integer returns
status, which is 0 on success and any other value for failure. When the
returned status is zero, then the second integer returns the actual value.
This change fixes this issue by replacing acpi_evaluate_integer() with
acpi_evaluate_object() and use acpi_extract_package() to extract results.
Fixes: 2ce6324ead ("ACPI: DPTF: Add PCH FIVR participant driver")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
162 lines
3.8 KiB
C
162 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* dptf_pch_fivr: DPTF PCH FIVR Participant driver
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* Copyright (c) 2020, Intel Corporation.
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*/
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#include <linux/acpi.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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struct pch_fivr_resp {
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u64 status;
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u64 result;
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};
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static int pch_fivr_read(acpi_handle handle, char *method, struct pch_fivr_resp *fivr_resp)
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{
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struct acpi_buffer resp = { sizeof(struct pch_fivr_resp), fivr_resp};
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struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
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struct acpi_buffer format = { sizeof("NN"), "NN" };
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union acpi_object *obj;
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acpi_status status;
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int ret = -EFAULT;
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status = acpi_evaluate_object(handle, method, NULL, &buffer);
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if (ACPI_FAILURE(status))
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return ret;
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obj = buffer.pointer;
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if (!obj || obj->type != ACPI_TYPE_PACKAGE)
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goto release_buffer;
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status = acpi_extract_package(obj, &format, &resp);
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if (ACPI_FAILURE(status))
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goto release_buffer;
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if (fivr_resp->status)
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goto release_buffer;
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ret = 0;
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release_buffer:
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kfree(buffer.pointer);
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return ret;
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}
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/*
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* Presentation of attributes which are defined for INT1045
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* They are:
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* freq_mhz_low_clock : Set PCH FIVR switching freq for
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* FIVR clock 19.2MHz and 24MHz
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* freq_mhz_high_clock : Set PCH FIVR switching freq for
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* FIVR clock 38.4MHz
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*/
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#define PCH_FIVR_SHOW(name, method) \
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static ssize_t name##_show(struct device *dev,\
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struct device_attribute *attr,\
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char *buf)\
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{\
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struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
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struct pch_fivr_resp fivr_resp;\
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int status;\
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\
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status = pch_fivr_read(acpi_dev->handle, #method, &fivr_resp);\
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if (status)\
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return status;\
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\
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return sprintf(buf, "%llu\n", fivr_resp.result);\
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}
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#define PCH_FIVR_STORE(name, method) \
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static ssize_t name##_store(struct device *dev,\
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struct device_attribute *attr,\
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const char *buf, size_t count)\
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{\
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struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
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acpi_status status;\
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u32 val;\
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\
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if (kstrtouint(buf, 0, &val) < 0)\
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return -EINVAL;\
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\
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status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\
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if (ACPI_SUCCESS(status))\
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return count;\
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\
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return -EINVAL;\
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}
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PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
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PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
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PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
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PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)
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static DEVICE_ATTR_RW(freq_mhz_low_clock);
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static DEVICE_ATTR_RW(freq_mhz_high_clock);
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static struct attribute *fivr_attrs[] = {
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&dev_attr_freq_mhz_low_clock.attr,
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&dev_attr_freq_mhz_high_clock.attr,
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NULL
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};
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static const struct attribute_group pch_fivr_attribute_group = {
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.attrs = fivr_attrs,
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.name = "pch_fivr_switch_frequency"
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};
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static int pch_fivr_add(struct platform_device *pdev)
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{
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struct acpi_device *acpi_dev;
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unsigned long long ptype;
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acpi_status status;
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int result;
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acpi_dev = ACPI_COMPANION(&(pdev->dev));
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if (!acpi_dev)
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return -ENODEV;
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status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype);
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if (ACPI_FAILURE(status) || ptype != 0x05)
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return -ENODEV;
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result = sysfs_create_group(&pdev->dev.kobj,
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&pch_fivr_attribute_group);
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if (result)
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return result;
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platform_set_drvdata(pdev, acpi_dev);
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return 0;
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}
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static int pch_fivr_remove(struct platform_device *pdev)
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{
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sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group);
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return 0;
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}
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static const struct acpi_device_id pch_fivr_device_ids[] = {
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{"INTC1045", 0},
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{"INTC1049", 0},
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{"", 0},
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};
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MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids);
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static struct platform_driver pch_fivr_driver = {
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.probe = pch_fivr_add,
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.remove = pch_fivr_remove,
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.driver = {
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.name = "dptf_pch_fivr",
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.acpi_match_table = pch_fivr_device_ids,
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},
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};
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module_platform_driver(pch_fivr_driver);
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MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver");
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