1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/int1092/intel_sar.c b/drivers/platform/x86/intel/int1092/intel_sar.c
new file mode 100644
index 000000000..e03943e63
--- /dev/null
+++ b/drivers/platform/x86/intel/int1092/intel_sar.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, Intel Corporation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/kobject.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+#include "intel_sar.h"
+
+/**
+ * get_int_value: Retrieve integer values from ACPI Object
+ * @obj: acpi_object pointer which has the integer value
+ * @out: output pointer will get integer value
+ *
+ * Function is used to retrieve integer value from acpi object.
+ *
+ * Return:
+ * * 0 on success
+ * * -EIO if there is an issue in acpi_object passed.
+ */
+static int get_int_value(union acpi_object *obj, int *out)
+{
+	if (!obj || obj->type != ACPI_TYPE_INTEGER)
+		return -EIO;
+	*out = (int)obj->integer.value;
+	return 0;
+}
+
+/**
+ * update_sar_data: sar data is updated based on regulatory mode
+ * @context: pointer to driver context structure
+ *
+ * sar_data is updated based on regulatory value
+ * context->reg_value will never exceed MAX_REGULATORY
+ */
+static void update_sar_data(struct wwan_sar_context *context)
+{
+	struct wwan_device_mode_configuration *config =
+		&context->config_data[context->reg_value];
+
+	if (config->device_mode_info &&
+	    context->sar_data.device_mode < config->total_dev_mode) {
+		int itr = 0;
+
+		for (itr = 0; itr < config->total_dev_mode; itr++) {
+			if (context->sar_data.device_mode ==
+				config->device_mode_info[itr].device_mode) {
+				struct wwan_device_mode_info *dev_mode =
+				&config->device_mode_info[itr];
+
+				context->sar_data.antennatable_index = dev_mode->antennatable_index;
+				context->sar_data.bandtable_index = dev_mode->bandtable_index;
+				context->sar_data.sartable_index = dev_mode->sartable_index;
+				break;
+			}
+		}
+	}
+}
+
+/**
+ * parse_package: parse acpi package for retrieving SAR information
+ * @context: pointer to driver context structure
+ * @item : acpi_object pointer
+ *
+ * Given acpi_object is iterated to retrieve information for each device mode.
+ * If a given package corresponding to a specific device mode is faulty, it is
+ * skipped and the specific entry in context structure will have the default value
+ * of zero. Decoding of subsequent device modes is realized by having "continue"
+ * statements in the for loop on encountering error in parsing given device mode.
+ *
+ * Return:
+ * AE_OK if success
+ * AE_ERROR on error
+ */
+static acpi_status parse_package(struct wwan_sar_context *context, union acpi_object *item)
+{
+	struct wwan_device_mode_configuration *data;
+	int value, itr, reg;
+	union acpi_object *num;
+
+	num = &item->package.elements[0];
+	if (get_int_value(num, &value) || value < 0 || value >= MAX_REGULATORY)
+		return AE_ERROR;
+
+	reg = value;
+
+	data = &context->config_data[reg];
+	if (data->total_dev_mode > MAX_DEV_MODES ||	data->total_dev_mode == 0 ||
+	    item->package.count <= data->total_dev_mode)
+		return AE_ERROR;
+
+	data->device_mode_info = kmalloc_array(data->total_dev_mode,
+					       sizeof(struct wwan_device_mode_info), GFP_KERNEL);
+	if (!data->device_mode_info)
+		return AE_ERROR;
+
+	for (itr = 0; itr < data->total_dev_mode; itr++) {
+		struct wwan_device_mode_info temp = { 0 };
+
+		num = &item->package.elements[itr + 1];
+		if (num->type != ACPI_TYPE_PACKAGE || num->package.count < TOTAL_DATA)
+			continue;
+		if (get_int_value(&num->package.elements[0], &temp.device_mode))
+			continue;
+		if (get_int_value(&num->package.elements[1], &temp.bandtable_index))
+			continue;
+		if (get_int_value(&num->package.elements[2], &temp.antennatable_index))
+			continue;
+		if (get_int_value(&num->package.elements[3], &temp.sartable_index))
+			continue;
+		data->device_mode_info[itr] = temp;
+	}
+	return AE_OK;
+}
+
+/**
+ * sar_get_device_mode: Extraction of information from BIOS via DSM calls
+ * @device: ACPI device for which to retrieve the data
+ *
+ * Retrieve the current device mode information from the BIOS.
+ *
+ * Return:
+ * AE_OK on success
+ * AE_ERROR on error
+ */
+static acpi_status sar_get_device_mode(struct platform_device *device)
+{
+	struct wwan_sar_context *context = dev_get_drvdata(&device->dev);
+	acpi_status status = AE_OK;
+	union acpi_object *out;
+	u32 rev = 0;
+	int value;
+
+	out = acpi_evaluate_dsm(context->handle, &context->guid, rev,
+				COMMAND_ID_DEV_MODE, NULL);
+	if (get_int_value(out, &value)) {
+		dev_err(&device->dev, "DSM cmd:%d Failed to retrieve value\n", COMMAND_ID_DEV_MODE);
+		status = AE_ERROR;
+		goto dev_mode_error;
+	}
+	context->sar_data.device_mode = value;
+	update_sar_data(context);
+	sysfs_notify(&device->dev.kobj, NULL, SYSFS_DATANAME);
+
+dev_mode_error:
+	ACPI_FREE(out);
+	return status;
+}
+
+static const struct acpi_device_id sar_device_ids[] = {
+	{ "INTC1092", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, sar_device_ids);
+
+static ssize_t intc_data_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct wwan_sar_context *context = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d %d %d %d\n", context->sar_data.device_mode,
+		      context->sar_data.bandtable_index,
+		      context->sar_data.antennatable_index,
+		      context->sar_data.sartable_index);
+}
+static DEVICE_ATTR_RO(intc_data);
+
+static ssize_t intc_reg_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct wwan_sar_context *context = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", context->reg_value);
+}
+
+static ssize_t intc_reg_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct wwan_sar_context *context = dev_get_drvdata(dev);
+	unsigned int value;
+	int read;
+
+	if (!count)
+		return -EINVAL;
+	read = kstrtouint(buf, 10, &value);
+	if (read < 0)
+		return read;
+	if (value >= MAX_REGULATORY)
+		return -EOVERFLOW;
+	context->reg_value = value;
+	update_sar_data(context);
+	sysfs_notify(&dev->kobj, NULL, SYSFS_DATANAME);
+	return count;
+}
+static DEVICE_ATTR_RW(intc_reg);
+
+static struct attribute *intcsar_attrs[] = {
+	&dev_attr_intc_data.attr,
+	&dev_attr_intc_reg.attr,
+	NULL
+};
+
+static struct attribute_group intcsar_group = {
+	.attrs = intcsar_attrs,
+};
+
+static void sar_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct platform_device *device = data;
+
+	if (event == SAR_EVENT) {
+		if (sar_get_device_mode(device) != AE_OK)
+			dev_err(&device->dev, "sar_get_device_mode error");
+	}
+}
+
+static void sar_get_data(int reg, struct wwan_sar_context *context)
+{
+	union acpi_object *out, req;
+	u32 rev = 0;
+
+	req.type = ACPI_TYPE_INTEGER;
+	req.integer.value = reg;
+	out = acpi_evaluate_dsm(context->handle, &context->guid, rev,
+				COMMAND_ID_CONFIG_TABLE, &req);
+	if (!out)
+		return;
+	if (out->type == ACPI_TYPE_PACKAGE && out->package.count >= 3 &&
+	    out->package.elements[0].type == ACPI_TYPE_INTEGER &&
+	    out->package.elements[1].type == ACPI_TYPE_INTEGER &&
+	    out->package.elements[2].type == ACPI_TYPE_PACKAGE &&
+	    out->package.elements[2].package.count > 0) {
+		context->config_data[reg].version = out->package.elements[0].integer.value;
+		context->config_data[reg].total_dev_mode =
+			out->package.elements[1].integer.value;
+		if (context->config_data[reg].total_dev_mode <= 0 ||
+		    context->config_data[reg].total_dev_mode > MAX_DEV_MODES) {
+			ACPI_FREE(out);
+			return;
+		}
+		parse_package(context, &out->package.elements[2]);
+	}
+	ACPI_FREE(out);
+}
+
+static int sar_probe(struct platform_device *device)
+{
+	struct wwan_sar_context *context;
+	int reg;
+	int result;
+
+	context = kzalloc(sizeof(*context), GFP_KERNEL);
+	if (!context)
+		return -ENOMEM;
+
+	context->sar_device = device;
+	context->handle = ACPI_HANDLE(&device->dev);
+	dev_set_drvdata(&device->dev, context);
+
+	result = guid_parse(SAR_DSM_UUID, &context->guid);
+	if (result) {
+		dev_err(&device->dev, "SAR UUID parse error: %d\n", result);
+		goto r_free;
+	}
+
+	for (reg = 0; reg < MAX_REGULATORY; reg++)
+		sar_get_data(reg, context);
+
+	if (sar_get_device_mode(device) != AE_OK) {
+		dev_err(&device->dev, "Failed to get device mode\n");
+		result = -EIO;
+		goto r_free;
+	}
+
+	result = sysfs_create_group(&device->dev.kobj, &intcsar_group);
+	if (result) {
+		dev_err(&device->dev, "sysfs creation failed\n");
+		goto r_free;
+	}
+
+	if (acpi_install_notify_handler(ACPI_HANDLE(&device->dev), ACPI_DEVICE_NOTIFY,
+					sar_notify, (void *)device) != AE_OK) {
+		dev_err(&device->dev, "Failed acpi_install_notify_handler\n");
+		result = -EIO;
+		goto r_sys;
+	}
+	return 0;
+
+r_sys:
+	sysfs_remove_group(&device->dev.kobj, &intcsar_group);
+r_free:
+	kfree(context);
+	return result;
+}
+
+static int sar_remove(struct platform_device *device)
+{
+	struct wwan_sar_context *context = dev_get_drvdata(&device->dev);
+	int reg;
+
+	acpi_remove_notify_handler(ACPI_HANDLE(&device->dev),
+				   ACPI_DEVICE_NOTIFY, sar_notify);
+	sysfs_remove_group(&device->dev.kobj, &intcsar_group);
+	for (reg = 0; reg < MAX_REGULATORY; reg++)
+		kfree(context->config_data[reg].device_mode_info);
+
+	kfree(context);
+	return 0;
+}
+
+static struct platform_driver sar_driver = {
+	.probe = sar_probe,
+	.remove = sar_remove,
+	.driver = {
+		.name = DRVNAME,
+		.acpi_match_table = ACPI_PTR(sar_device_ids)
+	}
+};
+module_platform_driver(sar_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Platform device driver for INTEL MODEM BIOS SAR");
+MODULE_AUTHOR("Shravan Sudhakar <s.shravan@intel.com>");