openwrt/target/linux/brcm2708/patches-4.1/0135-thermal-bcm2835-Use-firmware-API.patch

From aaff8adb4df57975a4a1334bb274ffce42c071e2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
Date: Mon, 20 Jul 2015 12:17:10 +0200
Subject: [PATCH 135/171] thermal: bcm2835: Use firmware API
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Use the new firmware API instead of the legacy mailbox API.
Remove retry loop on failure to read temperature.
Clean up code.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
 arch/arm/boot/dts/bcm2708_common.dtsi |   1 +
 drivers/thermal/bcm2835-thermal.c     | 197 +++++++++++++---------------------
 2 files changed, 75 insertions(+), 123 deletions(-)

--- a/arch/arm/boot/dts/bcm2708_common.dtsi
+++ b/arch/arm/boot/dts/bcm2708_common.dtsi
@@ -230,6 +230,7 @@
 
 		thermal: thermal {
 			compatible = "brcm,bcm2835-thermal";
+			firmware = <&firmware>;
 		};
 	};
 
--- a/drivers/thermal/bcm2835-thermal.c
+++ b/drivers/thermal/bcm2835-thermal.c
@@ -12,161 +12,113 @@
 * consent.
 *****************************************************************************/
 
-#include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
-#include <linux/platform_data/mailbox-bcm2708.h>
 #include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/sysfs.h>
 #include <linux/thermal.h>
+#include <soc/bcm2835/raspberrypi-firmware.h>
 
-
-/* --- DEFINITIONS --- */
-#define MODULE_NAME "bcm2835_thermal"
-
-/*#define THERMAL_DEBUG_ENABLE*/
-
-#ifdef THERMAL_DEBUG_ENABLE
-#define print_debug(fmt,...) printk(KERN_INFO "%s:%s:%d: "fmt"\n", MODULE_NAME, __func__, __LINE__, ##__VA_ARGS__)
-#else
-#define print_debug(fmt,...)
-#endif
-#define print_err(fmt,...) printk(KERN_ERR "%s:%s:%d: "fmt"\n", MODULE_NAME, __func__,__LINE__, ##__VA_ARGS__)
-
-#define VC_TAG_GET_TEMP 0x00030006
-#define VC_TAG_GET_MAX_TEMP 0x0003000A
-
-typedef enum {
-	TEMP,
-	MAX_TEMP,
-} temp_type;
-
-/* --- STRUCTS --- */
-/* tag part of the message */
-struct vc_msg_tag {
-	uint32_t tag_id;		/* the tag ID for the temperature */
-	uint32_t buffer_size;	/* size of the buffer (should be 8) */
-	uint32_t request_code;	/* identifies message as a request (should be 0) */
-	uint32_t id;			/* extra ID field (should be 0) */
-	uint32_t val;			/* returned value of the temperature */
-};
-
-/* message structure to be sent to videocore */
-struct vc_msg {
-	uint32_t msg_size;		/* simply, sizeof(struct vc_msg) */
-	uint32_t request_code;		/* holds various information like the success and number of bytes returned (refer to mailboxes wiki) */
-	struct vc_msg_tag tag;		/* the tag structure above to make */
-	uint32_t end_tag;		/* an end identifier, should be set to NULL */
-};
-
-struct bcm2835_thermal_data {
-	struct thermal_zone_device *thermal_dev;
-	struct vc_msg msg;
-};
-
-/* --- GLOBALS --- */
-static struct bcm2835_thermal_data bcm2835_data;
-
-/* Thermal Device Operations */
-static struct thermal_zone_device_ops ops;
-
-/* --- FUNCTIONS --- */
-
-static int bcm2835_get_temp_or_max(struct thermal_zone_device *thermal_dev, unsigned long *temp, unsigned tag_id)
+static int bcm2835_thermal_get_property(struct thermal_zone_device *tz,
+					unsigned long *temp, u32 tag)
 {
-	int result = -1, retry = 3;
-	print_debug("IN");
+	struct rpi_firmware *fw = tz->devdata;
+	struct {
+		u32 id;
+		u32 val;
+	} packet;
+	int ret;
 
 	*temp = 0;
-	while (result != 0 && retry-- > 0) {
-		/* wipe all previous message data */
-		memset(&bcm2835_data.msg, 0, sizeof bcm2835_data.msg);
-
-		/* prepare message */
-		bcm2835_data.msg.msg_size = sizeof bcm2835_data.msg;
-		bcm2835_data.msg.tag.buffer_size = 8;
-		bcm2835_data.msg.tag.tag_id = tag_id;
-
-		/* send the message */
-		result = bcm_mailbox_property(&bcm2835_data.msg, sizeof bcm2835_data.msg);
-		print_debug("Got %stemperature as %u (%d,%x)\n", tag_id==VC_TAG_GET_MAX_TEMP ? "max ":"", (uint)bcm2835_data.msg.tag.val, result, bcm2835_data.msg.request_code);
-		if (!(bcm2835_data.msg.request_code & 0x80000000))
-			result = -1;
+	packet.id = 0;
+	ret = rpi_firmware_property(fw, tag, &packet, sizeof(packet));
+	if (ret) {
+		dev_err(&tz->device, "Failed to get temperature\n");
+		return ret;
 	}
 
-	/* check if it was all ok and return the rate in milli degrees C */
-	if (result == 0)
-		*temp = (uint)bcm2835_data.msg.tag.val;
-	else
-		print_err("Failed to get temperature! (%x:%d)\n", tag_id, result);
-	print_debug("OUT");
-	return result;
+	*temp = packet.val;
+	dev_dbg(&tz->device, "%stemp=%lu\n",
+		tag == RPI_FIRMWARE_GET_MAX_TEMPERATURE ? "max" : "", *temp);
+
+	return 0;
 }
 
-static int bcm2835_get_temp(struct thermal_zone_device *thermal_dev, unsigned long *temp)
+static int bcm2835_thermal_get_temp(struct thermal_zone_device *tz,
+				    unsigned long *temp)
 {
-	return bcm2835_get_temp_or_max(thermal_dev, temp, VC_TAG_GET_TEMP);
+	return bcm2835_thermal_get_property(tz, temp,
+					    RPI_FIRMWARE_GET_TEMPERATURE);
 }
 
-static int bcm2835_get_max_temp(struct thermal_zone_device *thermal_dev, int trip_num, unsigned long *temp)
+static int bcm2835_thermal_get_max_temp(struct thermal_zone_device *tz,
+					int trip, unsigned long *temp)
 {
-	return bcm2835_get_temp_or_max(thermal_dev, temp, VC_TAG_GET_MAX_TEMP);
+	/*
+	 * The maximum safe temperature of the SoC.
+	 * Overclock may be disabled above this temperature.
+	 */
+	return bcm2835_thermal_get_property(tz, temp,
+					    RPI_FIRMWARE_GET_MAX_TEMPERATURE);
 }
 
-static int bcm2835_get_trip_type(struct thermal_zone_device * thermal_dev, int trip_num, enum thermal_trip_type *trip_type)
+static int bcm2835_thermal_get_trip_type(struct thermal_zone_device *tz,
+					 int trip, enum thermal_trip_type *type)
 {
-	*trip_type = THERMAL_TRIP_HOT;
+	*type = THERMAL_TRIP_HOT;
+
 	return 0;
 }
 
-
-static int bcm2835_get_mode(struct thermal_zone_device *thermal_dev, enum thermal_device_mode *dev_mode)
+static int bcm2835_thermal_get_mode(struct thermal_zone_device *tz,
+				    enum thermal_device_mode *mode)
 {
-	*dev_mode = THERMAL_DEVICE_ENABLED;
+	*mode = THERMAL_DEVICE_ENABLED;
+
 	return 0;
 }
 
+static struct thermal_zone_device_ops ops  = {
+	.get_temp = bcm2835_thermal_get_temp,
+	.get_trip_temp = bcm2835_thermal_get_max_temp,
+	.get_trip_type = bcm2835_thermal_get_trip_type,
+	.get_mode = bcm2835_thermal_get_mode,
+};
 
 static int bcm2835_thermal_probe(struct platform_device *pdev)
 {
-	print_debug("IN");
-	print_debug("THERMAL Driver has been probed!");
-
-	/* check that the device isn't null!*/
-	if(pdev == NULL)
-	{
-		print_debug("Platform device is empty!");
-		return -ENODEV;
+	struct device_node *fw_np;
+	struct rpi_firmware *fw;
+	struct thermal_zone_device *tz;
+
+	fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
+/* Remove comment when booting without Device Tree is no longer supported
+	if (!fw_np) {
+		dev_err(&pdev->dev, "Missing firmware node\n");
+		return -ENOENT;
 	}
-
-	if(!(bcm2835_data.thermal_dev = thermal_zone_device_register("bcm2835_thermal",  1, 0, NULL, &ops, NULL, 0, 0)))
-	{
-		print_debug("Unable to register the thermal device!");
-		return -EFAULT;
+*/
+	fw = rpi_firmware_get(fw_np);
+	if (!fw)
+		return -EPROBE_DEFER;
+
+	tz = thermal_zone_device_register("bcm2835_thermal", 1, 0, fw, &ops,
+					  NULL, 0, 0);
+	if (IS_ERR(tz)) {
+		dev_err(&pdev->dev, "Failed to register the thermal device\n");
+		return PTR_ERR(tz);
 	}
+
+	platform_set_drvdata(pdev, tz);
+
 	return 0;
 }
 
-
 static int bcm2835_thermal_remove(struct platform_device *pdev)
 {
-	print_debug("IN");
-
-	thermal_zone_device_unregister(bcm2835_data.thermal_dev);
-
-	print_debug("OUT");
+	thermal_zone_device_unregister(platform_get_drvdata(pdev));
 
 	return 0;
 }
 
-static struct thermal_zone_device_ops ops  = {
-	.get_temp = bcm2835_get_temp,
-	.get_trip_temp = bcm2835_get_max_temp,
-	.get_trip_type = bcm2835_get_trip_type,
-	.get_mode = bcm2835_get_mode,
-};
-
 static const struct of_device_id bcm2835_thermal_of_match_table[] = {
 	{ .compatible = "brcm,bcm2835-thermal", },
 	{},
@@ -177,14 +129,13 @@ static struct platform_driver bcm2835_th
 	.probe = bcm2835_thermal_probe,
 	.remove = bcm2835_thermal_remove,
 	.driver = {
-				.name = "bcm2835_thermal",
-				.owner = THIS_MODULE,
-				.of_match_table = bcm2835_thermal_of_match_table,
-			},
+		.name = "bcm2835_thermal",
+		.of_match_table = bcm2835_thermal_of_match_table,
+	},
 };
+module_platform_driver(bcm2835_thermal_driver);
 
-MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Dorian Peake");
+MODULE_AUTHOR("Noralf Trønnes");
 MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
-
-module_platform_driver(bcm2835_thermal_driver);
+MODULE_LICENSE("GPL");