ACPI / LPAT: Common table processing functions

Since LPAT table processing is also required for other thermal drivers,
moved LPAT table related functions from intel PMIC driver (intel_pmic.c)
to a stand alonge module with exported interfaces.
In this way there will be no code duplication.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index f74317c..d22253d 100644 (file)
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -55,6 +55,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
 ifdef CONFIG_ACPI_VIDEO
 acpi-y                         += video_detect.o
 endif
+acpi-y                         += acpi_lpat.o
 
 # These are (potentially) separate modules
 

diff --git a/drivers/acpi/acpi_lpat.c b/drivers/acpi/acpi_lpat.c
new file mode 100644 (file)
index 0000000..feb61c1
--- /dev/null
+++ b/drivers/acpi/acpi_lpat.c
@@ -0,0 +1,161 @@
+/*
+ * acpi_lpat.c - LPAT table processing functions
+ *
+ * Copyright (C) 2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <acpi/acpi_lpat.h>
+
+/**
+ * acpi_lpat_raw_to_temp(): Return temperature from raw value through
+ * LPAT conversion table
+ *
+ * @lpat_table: the temperature_raw mapping table structure
+ * @raw: the raw value, used as a key to get the temerature from the
+ *       above mapping table
+ *
+ * A positive converted temperarure value will be returned on success,
+ * a negative errno will be returned in error cases.
+ */
+int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
+                         int raw)
+{
+       int i, delta_temp, delta_raw, temp;
+       struct acpi_lpat *lpat = lpat_table->lpat;
+
+       for (i = 0; i < lpat_table->lpat_count - 1; i++) {
+               if ((raw >= lpat[i].raw && raw <= lpat[i+1].raw) ||
+                   (raw <= lpat[i].raw && raw >= lpat[i+1].raw))
+                       break;
+       }
+
+       if (i == lpat_table->lpat_count - 1)
+               return -ENOENT;
+
+       delta_temp = lpat[i+1].temp - lpat[i].temp;
+       delta_raw = lpat[i+1].raw - lpat[i].raw;
+       temp = lpat[i].temp + (raw - lpat[i].raw) * delta_temp / delta_raw;
+
+       return temp;
+}
+EXPORT_SYMBOL_GPL(acpi_lpat_raw_to_temp);
+
+/**
+ * acpi_lpat_temp_to_raw(): Return raw value from temperature through
+ * LPAT conversion table
+ *
+ * @lpat: the temperature_raw mapping table
+ * @temp: the temperature, used as a key to get the raw value from the
+ *        above mapping table
+ *
+ * A positive converted temperature value will be returned on success,
+ * a negative errno will be returned in error cases.
+ */
+int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
+                         int temp)
+{
+       int i, delta_temp, delta_raw, raw;
+       struct acpi_lpat *lpat = lpat_table->lpat;
+
+       for (i = 0; i < lpat_table->lpat_count - 1; i++) {
+               if (temp >= lpat[i].temp && temp <= lpat[i+1].temp)
+                       break;
+       }
+
+       if (i ==  lpat_table->lpat_count - 1)
+               return -ENOENT;
+
+       delta_temp = lpat[i+1].temp - lpat[i].temp;
+       delta_raw = lpat[i+1].raw - lpat[i].raw;
+       raw = lpat[i].raw + (temp - lpat[i].temp) * delta_raw / delta_temp;
+
+       return raw;
+}
+EXPORT_SYMBOL_GPL(acpi_lpat_temp_to_raw);
+
+/**
+ * acpi_lpat_get_conversion_table(): Parse ACPI LPAT table if present.
+ *
+ * @handle: Handle to acpi device
+ *
+ * Parse LPAT table to a struct of type acpi_lpat_table. On success
+ * it returns a pointer to newly allocated table. This table must
+ * be freed by the caller when finished processing, using a call to
+ * acpi_lpat_free_conversion_table.
+ */
+struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(acpi_handle
+                                                                 handle)
+{
+       struct acpi_lpat_conversion_table *lpat_table = NULL;
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+       union acpi_object *obj_p, *obj_e;
+       int *lpat, i;
+       acpi_status status;
+
+       status = acpi_evaluate_object(handle, "LPAT", NULL, &buffer);
+       if (ACPI_FAILURE(status))
+               return NULL;
+
+       obj_p = (union acpi_object *)buffer.pointer;
+       if (!obj_p || (obj_p->type != ACPI_TYPE_PACKAGE) ||
+           (obj_p->package.count % 2) || (obj_p->package.count < 4))
+               goto out;
+
+       lpat = kcalloc(obj_p->package.count, sizeof(int), GFP_KERNEL);
+       if (!lpat)
+               goto out;
+
+       for (i = 0; i < obj_p->package.count; i++) {
+               obj_e = &obj_p->package.elements[i];
+               if (obj_e->type != ACPI_TYPE_INTEGER) {
+                       kfree(lpat);
+                       goto out;
+               }
+               lpat[i] = (s64)obj_e->integer.value;
+       }
+
+       lpat_table = kzalloc(sizeof(*lpat_table), GFP_KERNEL);
+       if (!lpat_table) {
+               kfree(lpat);
+               goto out;
+       }
+
+       lpat_table->lpat = (struct acpi_lpat *)lpat;
+       lpat_table->lpat_count = obj_p->package.count / 2;
+
+out:
+       kfree(buffer.pointer);
+       return lpat_table;
+}
+EXPORT_SYMBOL_GPL(acpi_lpat_get_conversion_table);
+
+/**
+ * acpi_lpat_free_conversion_table(): Free LPAT table.
+ *
+ * @lpat_table: the temperature_raw mapping table structure
+ *
+ * Frees the LPAT table previously allocated by a call to
+ * acpi_lpat_get_conversion_table.
+ */
+void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
+                                    *lpat_table)
+{
+       if (lpat_table) {
+               kfree(lpat_table->lpat);
+               kfree(lpat_table);
+       }
+}
+EXPORT_SYMBOL_GPL(acpi_lpat_free_conversion_table);
+
+MODULE_LICENSE("GPL");

diff --git a/include/acpi/acpi_lpat.h b/include/acpi/acpi_lpat.h
new file mode 100644 (file)
index 0000000..da37e12
--- /dev/null
+++ b/include/acpi/acpi_lpat.h
@@ -0,0 +1,65 @@
+/*
+ * acpi_lpat.h - LPAT table processing functions
+ *
+ * Copyright (C) 2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef ACPI_LPAT_H
+#define ACPI_LPAT_H
+
+struct acpi_lpat {
+       int temp;
+       int raw;
+};
+
+struct acpi_lpat_conversion_table {
+       struct acpi_lpat *lpat;
+       int lpat_count;
+};
+
+#ifdef CONFIG_ACPI
+
+int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
+                         int raw);
+int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
+                         int temp);
+struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(acpi_handle
+                                                                 handle);
+void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
+                                    *lpat_table);
+
+#else
+static int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
+                                int raw)
+{
+       return 0;
+}
+
+static int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
+                                int temp)
+{
+       return 0;
+}
+
+static struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(
+                                                       acpi_handle handle)
+{
+       return NULL;
+}
+
+static void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
+                                           *lpat_table)
+{
+}
+
+#endif
+#endif