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From 97a6a1f61eb949892457a739435fd5280fc800f8 Mon Sep 17 00:00:00 2001
From: XECDesign <XECDesign@users.noreply.github.com>
Date: Wed, 29 Aug 2018 15:08:30 +0100
Subject: [PATCH 412/454] PoE HAT driver cleanup
* Fix undeclared variable in rpi_poe_fan_suspend
* Add SPDX-License-Identifier
* Expand PoE acronym in Kconfig help
* Give clearer error message on of_property_count_u32_elems fail
* Add documentation
* Add vendor to of_device_id compatible string.
* Rename m_data_s struct to fw_data_s
* Fix typos
Fixes: #2665
Signed-off-by: Serge Schneider <serge@raspberrypi.org>
---
.../devicetree/bindings/hwmon/rpi-poe-fan.txt | 55 +++++++++++++++++++
Documentation/hwmon/rpi-poe-fan | 15 +++++
.../arm/boot/dts/overlays/rpi-poe-overlay.dts | 2 +-
drivers/hwmon/Kconfig | 5 +-
drivers/hwmon/rpi-poe-fan.c | 39 ++++++-------
5 files changed, 90 insertions(+), 26 deletions(-)
create mode 100644 Documentation/devicetree/bindings/hwmon/rpi-poe-fan.txt
create mode 100644 Documentation/hwmon/rpi-poe-fan
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/rpi-poe-fan.txt
@@ -0,0 +1,55 @@
+Bindings for the Raspberry Pi PoE HAT fan
+
+Required properties:
+- compatible : "raspberrypi,rpi-poe-fan"
+- firmware : Reference to the RPi firmware device node
+- pwms : the PWM that is used to control the PWM fan
+- cooling-levels : PWM duty cycle values in a range from 0 to 255
+ which correspond to thermal cooling states
+
+Example:
+ fan0: rpi-poe-fan@0 {
+ compatible = "raspberrypi,rpi-poe-fan";
+ firmware = <&firmware>;
+ cooling-min-state = <0>;
+ cooling-max-state = <3>;
+ #cooling-cells = <2>;
+ cooling-levels = <0 50 150 255>;
+ status = "okay";
+ };
+
+ thermal-zones {
+ cpu_thermal: cpu-thermal {
+ trips {
+ threshold: trip-point@0 {
+ temperature = <45000>;
+ hysteresis = <5000>;
+ type = "active";
+ };
+ target: trip-point@1 {
+ temperature = <50000>;
+ hysteresis = <2000>;
+ type = "active";
+ };
+ cpu_hot: cpu_hot@0 {
+ temperature = <55000>;
+ hysteresis = <2000>;
+ type = "active";
+ };
+ };
+ cooling-maps {
+ map0 {
+ trip = <&threshold>;
+ cooling-device = <&fan0 0 1>;
+ };
+ map1 {
+ trip = <&target>;
+ cooling-device = <&fan0 1 2>;
+ };
+ map2 {
+ trip = <&cpu_hot>;
+ cooling-device = <&fan0 2 3>;
+ };
+ };
+ };
+ };
--- /dev/null
+++ b/Documentation/hwmon/rpi-poe-fan
@@ -0,0 +1,15 @@
+Kernel driver rpi-poe-fan
+=====================
+
+This driver enables the use of the Raspberry Pi PoE HAT fan.
+
+Author: Serge Schneider <serge@raspberrypi.org>
+
+Description
+-----------
+
+The driver implements a simple interface for driving the Raspberry Pi PoE
+(Power over Ethernet) HAT fan. The driver passes commands to the Raspberry Pi
+firmware through the mailbox property interface. The firmware then forwards
+the commands to the board over I2C on the ID_EEPROM pins. The driver exposes
+the fan to the user space through the hwmon sysfs interface.
--- a/arch/arm/boot/dts/overlays/rpi-poe-overlay.dts
+++ b/arch/arm/boot/dts/overlays/rpi-poe-overlay.dts
@@ -11,7 +11,7 @@
target-path = "/";
__overlay__ {
fan0: rpi-poe-fan@0 {
- compatible = "rpi-poe-fan";
+ compatible = "raspberrypi,rpi-poe-fan";
firmware = <&firmware>;
cooling-min-state = <0>;
cooling-max-state = <3>;
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1287,11 +1287,12 @@ config SENSORS_PWM_FAN
will be called pwm-fan.
config SENSORS_RPI_POE_FAN
- tristate "Raspberry Pi POE HAT fan"
+ tristate "Raspberry Pi PoE HAT fan"
depends on RASPBERRYPI_FIRMWARE
depends on THERMAL || THERMAL=n
help
- If you say yes here you get support for Raspberry Pi POE HAT fan.
+ If you say yes here you get support for Raspberry Pi PoE (Power over
+ Ethernet) HAT fan.
This driver can also be built as a module. If so, the module
will be called rpi-poe-fan.
--- a/drivers/hwmon/rpi-poe-fan.c
+++ b/drivers/hwmon/rpi-poe-fan.c
@@ -1,20 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
/*
- * rpi-poe-fan.c - Hwmon driver for Raspberry Pi POE HAT fan.
+ * rpi-poe-fan.c - Hwmon driver for Raspberry Pi PoE HAT fan.
*
* Copyright (C) 2018 Raspberry Pi (Trading) Ltd.
* Based on pwm-fan.c by Kamil Debski <k.debski@samsung.com>
*
* Author: Serge Schneider <serge@raspberrypi.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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/hwmon.h>
@@ -46,41 +37,41 @@ struct rpi_poe_fan_ctx {
struct notifier_block nb;
};
-struct m_data_s{
+struct fw_tag_data_s{
u32 reg;
u32 val;
u32 ret;
};
static int write_reg(struct rpi_firmware *fw, u32 reg, u32 *val){
- struct m_data_s m_data = {
+ struct fw_tag_data_s fw_tag_data = {
.reg = reg,
.val = *val
};
int ret;
ret = rpi_firmware_property(fw, RPI_FIRMWARE_SET_POE_HAT_VAL,
- &m_data, sizeof(m_data));
+ &fw_tag_data, sizeof(fw_tag_data));
if (ret) {
return ret;
- } else if (m_data.ret) {
+ } else if (fw_tag_data.ret) {
return -EIO;
}
return 0;
}
static int read_reg(struct rpi_firmware *fw, u32 reg, u32 *val){
- struct m_data_s m_data = {
+ struct fw_tag_data_s fw_tag_data = {
.reg = reg,
};
int ret;
ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_POE_HAT_VAL,
- &m_data, sizeof(m_data));
+ &fw_tag_data, sizeof(fw_tag_data));
if (ret) {
return ret;
- } else if (m_data.ret) {
+ } else if (fw_tag_data.ret) {
return -EIO;
}
- *val = m_data.val;
+ *val = fw_tag_data.val;
return 0;
}
@@ -268,7 +259,8 @@ static int rpi_poe_fan_of_get_cooling_da
ret = of_property_count_u32_elems(np, "cooling-levels");
if (ret <= 0) {
- dev_err(dev, "Wrong data!\n");
+ dev_err(dev, "cooling-levels property missing or invalid: %d\n",
+ ret);
return ret ? : -EINVAL;
}
@@ -397,10 +389,11 @@ static int rpi_poe_fan_suspend(struct de
{
struct rpi_poe_fan_ctx *ctx = dev_get_drvdata(dev);
u32 value = 0;
+ int ret = 0;
if (ctx->pwm_value != value)
ret = write_reg(ctx->fw, POE_CUR_PWM, &value);
- return 0;
+ return ret;
}
static int rpi_poe_fan_resume(struct device *dev)
@@ -420,7 +413,7 @@ static SIMPLE_DEV_PM_OPS(rpi_poe_fan_pm,
rpi_poe_fan_resume);
static const struct of_device_id of_rpi_poe_fan_match[] = {
- { .compatible = "rpi-poe-fan", },
+ { .compatible = "raspberrypi,rpi-poe-fan", },
{},
};
MODULE_DEVICE_TABLE(of, of_rpi_poe_fan_match);
@@ -439,5 +432,5 @@ module_platform_driver(rpi_poe_fan_drive
MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
MODULE_ALIAS("platform:rpi-poe-fan");
-MODULE_DESCRIPTION("Raspberry Pi POE HAT fan driver");
+MODULE_DESCRIPTION("Raspberry Pi PoE HAT fan driver");
MODULE_LICENSE("GPL");
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