diff options
Diffstat (limited to 'drivers/acpi/dptf/dptf_pch_fivr.c')
| -rw-r--r-- | drivers/acpi/dptf/dptf_pch_fivr.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c b/drivers/acpi/dptf/dptf_pch_fivr.c new file mode 100644 index 000000000..550b9081f --- /dev/null +++ b/drivers/acpi/dptf/dptf_pch_fivr.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * dptf_pch_fivr: DPTF PCH FIVR Participant driver + * Copyright (c) 2020, Intel Corporation. + */ + +#include <linux/acpi.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +struct pch_fivr_resp { + u64 status; + u64 result; +}; + +static int pch_fivr_read(acpi_handle handle, char *method, struct pch_fivr_resp *fivr_resp) +{ + struct acpi_buffer resp = { sizeof(struct pch_fivr_resp), fivr_resp}; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + struct acpi_buffer format = { sizeof("NN"), "NN" }; + union acpi_object *obj; + acpi_status status; + int ret = -EFAULT; + + status = acpi_evaluate_object(handle, method, NULL, &buffer); + if (ACPI_FAILURE(status)) + return ret; + + obj = buffer.pointer; + if (!obj || obj->type != ACPI_TYPE_PACKAGE) + goto release_buffer; + + status = acpi_extract_package(obj, &format, &resp); + if (ACPI_FAILURE(status)) + goto release_buffer; + + if (fivr_resp->status) + goto release_buffer; + + ret = 0; + +release_buffer: + kfree(buffer.pointer); + return ret; +} + +/* + * Presentation of attributes which are defined for INT1045 + * They are: + * freq_mhz_low_clock : Set PCH FIVR switching freq for + * FIVR clock 19.2MHz and 24MHz + * freq_mhz_high_clock : Set PCH FIVR switching freq for + * FIVR clock 38.4MHz + */ +#define PCH_FIVR_SHOW(name, method) \ +static ssize_t name##_show(struct device *dev,\ + struct device_attribute *attr,\ + char *buf)\ +{\ + struct acpi_device *acpi_dev = dev_get_drvdata(dev);\ + struct pch_fivr_resp fivr_resp;\ + int status;\ +\ + status = pch_fivr_read(acpi_dev->handle, #method, &fivr_resp);\ + if (status)\ + return status;\ +\ + return sprintf(buf, "%llu\n", fivr_resp.result);\ +} + +#define PCH_FIVR_STORE(name, method) \ +static ssize_t name##_store(struct device *dev,\ + struct device_attribute *attr,\ + const char *buf, size_t count)\ +{\ + struct acpi_device *acpi_dev = dev_get_drvdata(dev);\ + acpi_status status;\ + u32 val;\ +\ + if (kstrtouint(buf, 0, &val) < 0)\ + return -EINVAL;\ +\ + status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\ + if (ACPI_SUCCESS(status))\ + return count;\ +\ + return -EINVAL;\ +} + +PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0) +PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1) +PCH_FIVR_STORE(freq_mhz_low_clock, RFC0) +PCH_FIVR_STORE(freq_mhz_high_clock, RFC1) + +static DEVICE_ATTR_RW(freq_mhz_low_clock); +static DEVICE_ATTR_RW(freq_mhz_high_clock); + +static struct attribute *fivr_attrs[] = { + &dev_attr_freq_mhz_low_clock.attr, + &dev_attr_freq_mhz_high_clock.attr, + NULL +}; + +static const struct attribute_group pch_fivr_attribute_group = { + .attrs = fivr_attrs, + .name = "pch_fivr_switch_frequency" +}; + +static int pch_fivr_add(struct platform_device *pdev) +{ + struct acpi_device *acpi_dev; + unsigned long long ptype; + acpi_status status; + int result; + + acpi_dev = ACPI_COMPANION(&(pdev->dev)); + if (!acpi_dev) + return -ENODEV; + + status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype); + if (ACPI_FAILURE(status) || ptype != 0x05) + return -ENODEV; + + result = sysfs_create_group(&pdev->dev.kobj, + &pch_fivr_attribute_group); + if (result) + return result; + + platform_set_drvdata(pdev, acpi_dev); + + return 0; +} + +static int pch_fivr_remove(struct platform_device *pdev) +{ + sysfs_remove_group(&pdev->dev.kobj, &pch_fivr_attribute_group); + + return 0; +} + +static const struct acpi_device_id pch_fivr_device_ids[] = { + {"INTC1045", 0}, + {"INTC1049", 0}, + {"", 0}, +}; +MODULE_DEVICE_TABLE(acpi, pch_fivr_device_ids); + +static struct platform_driver pch_fivr_driver = { + .probe = pch_fivr_add, + .remove = pch_fivr_remove, + .driver = { + .name = "dptf_pch_fivr", + .acpi_match_table = pch_fivr_device_ids, + }, +}; + +module_platform_driver(pch_fivr_driver); + +MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("ACPI DPTF PCH FIVR driver"); |