[PATCH V2 2/2] thermal: broadcom: add Raspberry Pi thermal driver
From: zajec5@gmail.com (Rafał Miłecki)
Date: 2017-03-18 00:06:03
Also in:
linux-devicetree, linux-pm
Subsystem:
the rest, thermal · Maintainers:
Linus Torvalds, Rafael J. Wysocki, Daniel Lezcano
From: Rafa? Mi?ecki <rafal@milecki.pl>
Raspberry Pi devices use BCM283[567] SoCs with a thermal device inside.
Querying it is possible using Raspberry specific firmware interface.
This simple driver allows reading SoC temperature.
Signed-off-by: Rafa? Mi?ecki <rafal@milecki.pl>
---
V2: Update Kconfig help message. I forgot to locally rebase & fixup before
sending, sorry.
---
drivers/thermal/Kconfig | 5 ++
drivers/thermal/Makefile | 1 +
drivers/thermal/broadcom/Kconfig | 7 +++
drivers/thermal/broadcom/Makefile | 1 +
drivers/thermal/broadcom/raspberrypi-thermal.c | 85 ++++++++++++++++++++++++++
5 files changed, 99 insertions(+)
create mode 100644 drivers/thermal/broadcom/Kconfig
create mode 100644 drivers/thermal/broadcom/Makefile
create mode 100644 drivers/thermal/broadcom/raspberrypi-thermal.c
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 776b34396144..008e173ec825 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig@@ -392,6 +392,11 @@ config MTK_THERMAL Enable this option if you want to have support for thermal management controller present in Mediatek SoCs +menu "Broadcom thermal drivers" +depends on ARCH_BCM || COMPILE_TEST +source "drivers/thermal/broadcom/Kconfig" +endmenu + menu "Texas Instruments thermal drivers" depends on ARCH_HAS_BANDGAP || COMPILE_TEST depends on HAS_IOMEM
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 7adae2029355..549d81b6363c 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile@@ -27,6 +27,7 @@ thermal_sys-$(CONFIG_CLOCK_THERMAL) += clock_cooling.o thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o # platform thermal drivers +obj-y += broadcom/ obj-$(CONFIG_QCOM_SPMI_TEMP_ALARM) += qcom-spmi-temp-alarm.o obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o obj-$(CONFIG_ROCKCHIP_THERMAL) += rockchip_thermal.o
diff --git a/drivers/thermal/broadcom/Kconfig b/drivers/thermal/broadcom/Kconfig
new file mode 100644
index 000000000000..2524b2ff16f6
--- /dev/null
+++ b/drivers/thermal/broadcom/Kconfig@@ -0,0 +1,7 @@ +config RASPBERRYPI_THERMAL + tristate "Raspberry Pi thermal driver" + depends on ARCH_BCM2835 || COMPILE_TEST + depends on RASPBERRYPI_FIRMWARE=y + help + This enables support for the RPi thermal that is part of BCM2835 SoC + and can be accessed using firmware interface.
diff --git a/drivers/thermal/broadcom/Makefile b/drivers/thermal/broadcom/Makefile
new file mode 100644
index 000000000000..5ea7f8819b7d
--- /dev/null
+++ b/drivers/thermal/broadcom/Makefile@@ -0,0 +1 @@ +obj-$(CONFIG_RASPBERRYPI_THERMAL) += raspberrypi-thermal.o
diff --git a/drivers/thermal/broadcom/raspberrypi-thermal.c b/drivers/thermal/broadcom/raspberrypi-thermal.c
new file mode 100644
index 000000000000..d9c1db06f806
--- /dev/null
+++ b/drivers/thermal/broadcom/raspberrypi-thermal.c@@ -0,0 +1,85 @@ +/* + * Copyright (C) 2017 Rafa? Mi?ecki <rafal@milecki.pl> + * + * 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. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/thermal.h> + +#include <soc/bcm2835/raspberrypi-firmware.h> + +struct rpi_thermal { + struct rpi_firmware *fw; +}; + +static int rpi_thermal_get_temp(void *data, int *temp) +{ + struct rpi_thermal *rpi_thermal = data; + struct { + u32 id; + u32 temp; + } tag_data = {}; + int err; + + err = rpi_firmware_property(rpi_thermal->fw, + RPI_FIRMWARE_GET_TEMPERATURE, + &tag_data, sizeof(tag_data)); + if (!err) + *temp = tag_data.temp; + + return err; +} + +const struct thermal_zone_of_device_ops rpi_thermal_ops = { + .get_temp = rpi_thermal_get_temp, +}; + +static int rpi_thermal_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rpi_thermal *rpi_thermal; + struct device_node *fw_np; + struct thermal_zone_device *tzd; + + rpi_thermal = devm_kzalloc(dev, sizeof(*rpi_thermal), GFP_KERNEL); + if (!rpi_thermal) + return -ENOMEM; + + fw_np = of_parse_phandle(dev->of_node, "firmware", 0); + if (!fw_np) { + dev_err(dev, "Failed to get firmware phandle\n"); + return -ENOENT; + } + + rpi_thermal->fw = rpi_firmware_get(fw_np); + of_node_put(fw_np); + if (!rpi_thermal->fw) + return -ENODEV; + + tzd = devm_thermal_zone_of_sensor_register(dev, 0, rpi_thermal, + &rpi_thermal_ops); + + return PTR_ERR_OR_ZERO(tzd); +} + +static const struct of_device_id rpi_thermal_of_match[] = { + { .compatible = "raspberrypi,bcm2835-thermal", }, + {}, +}; +MODULE_DEVICE_TABLE(of, rpi_thermal_of_match); + +static struct platform_driver rpi_thermal_driver = { + .probe = rpi_thermal_probe, + .driver = { + .name = "raspberrypi-thermal", + .of_match_table = rpi_thermal_of_match, + }, +}; +module_platform_driver(rpi_thermal_driver); + +MODULE_DESCRIPTION("Raspberry Pi thermal driver"); +MODULE_LICENSE("GPL v2");
--
2.11.0