--- /dev/null
+From bcb7dd9ef206f7d646ed8dac6fe7772083714253 Mon Sep 17 00:00:00 2001
+From: Stefan Wahren <stefan.wahren@i2se.com>
+Date: Fri, 31 Mar 2017 20:03:06 +0000
+Subject: [PATCH] thermal: bcm2835: add thermal driver for bcm2835 SoC
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Add basic thermal driver for bcm2835 SoC.
+
+This driver currently make sure that tsense HW block is set up
+correctly.
+
+Tested-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
+Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
+Acked-by: Eric Anholt <eric@anholt.net>
+Acked-by: Eduardo Valentin <edubezval@gmail.com>
+Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
+---
+ drivers/thermal/Kconfig | 8 +
+ drivers/thermal/Makefile | 1 +
+ drivers/thermal/bcm2835_thermal.c | 314 ++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 323 insertions(+)
+ create mode 100644 drivers/thermal/bcm2835_thermal.c
+
+--- a/drivers/thermal/Kconfig
++++ b/drivers/thermal/Kconfig
+@@ -391,4 +391,12 @@ config QCOM_SPMI_TEMP_ALARM
+ real time die temperature if an ADC is present or an estimate of the
+ temperature based upon the over temperature stage value.
+
++config BCM2835_THERMAL
++ tristate "Thermal sensors on bcm2835 SoC"
++ depends on ARCH_BCM2835 || COMPILE_TEST
++ depends on HAS_IOMEM
++ depends on THERMAL_OF
++ help
++ Support for thermal sensors on Broadcom bcm2835 SoCs.
++
+ endif
+--- a/drivers/thermal/Makefile
++++ b/drivers/thermal/Makefile
+@@ -48,3 +48,4 @@ obj-$(CONFIG_INTEL_PCH_THERMAL) += intel
+ obj-$(CONFIG_ST_THERMAL) += st/
+ obj-$(CONFIG_TEGRA_SOCTHERM) += tegra_soctherm.o
+ obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
++obj-$(CONFIG_BCM2835_THERMAL) += bcm2835_thermal.o
+--- /dev/null
++++ b/drivers/thermal/bcm2835_thermal.c
+@@ -0,0 +1,314 @@
++/*
++ * Driver for Broadcom BCM2835 SoC temperature sensor
++ *
++ * Copyright (C) 2016 Martin Sperl
++ *
++ * 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/clk.h>
++#include <linux/debugfs.h>
++#include <linux/device.h>
++#include <linux/err.h>
++#include <linux/io.h>
++#include <linux/kernel.h>
++#include <linux/module.h>
++#include <linux/of.h>
++#include <linux/of_address.h>
++#include <linux/of_device.h>
++#include <linux/platform_device.h>
++#include <linux/thermal.h>
++
++#define BCM2835_TS_TSENSCTL 0x00
++#define BCM2835_TS_TSENSSTAT 0x04
++
++#define BCM2835_TS_TSENSCTL_PRWDW BIT(0)
++#define BCM2835_TS_TSENSCTL_RSTB BIT(1)
++
++/*
++ * bandgap reference voltage in 6 mV increments
++ * 000b = 1178 mV, 001b = 1184 mV, ... 111b = 1220 mV
++ */
++#define BCM2835_TS_TSENSCTL_CTRL_BITS 3
++#define BCM2835_TS_TSENSCTL_CTRL_SHIFT 2
++#define BCM2835_TS_TSENSCTL_CTRL_MASK \
++ GENMASK(BCM2835_TS_TSENSCTL_CTRL_BITS + \
++ BCM2835_TS_TSENSCTL_CTRL_SHIFT - 1, \
++ BCM2835_TS_TSENSCTL_CTRL_SHIFT)
++#define BCM2835_TS_TSENSCTL_CTRL_DEFAULT 1
++#define BCM2835_TS_TSENSCTL_EN_INT BIT(5)
++#define BCM2835_TS_TSENSCTL_DIRECT BIT(6)
++#define BCM2835_TS_TSENSCTL_CLR_INT BIT(7)
++#define BCM2835_TS_TSENSCTL_THOLD_SHIFT 8
++#define BCM2835_TS_TSENSCTL_THOLD_BITS 10
++#define BCM2835_TS_TSENSCTL_THOLD_MASK \
++ GENMASK(BCM2835_TS_TSENSCTL_THOLD_BITS + \
++ BCM2835_TS_TSENSCTL_THOLD_SHIFT - 1, \
++ BCM2835_TS_TSENSCTL_THOLD_SHIFT)
++/*
++ * time how long the block to be asserted in reset
++ * which based on a clock counter (TSENS clock assumed)
++ */
++#define BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT 18
++#define BCM2835_TS_TSENSCTL_RSTDELAY_BITS 8
++#define BCM2835_TS_TSENSCTL_REGULEN BIT(26)
++
++#define BCM2835_TS_TSENSSTAT_DATA_BITS 10
++#define BCM2835_TS_TSENSSTAT_DATA_SHIFT 0
++#define BCM2835_TS_TSENSSTAT_DATA_MASK \
++ GENMASK(BCM2835_TS_TSENSSTAT_DATA_BITS + \
++ BCM2835_TS_TSENSSTAT_DATA_SHIFT - 1, \
++ BCM2835_TS_TSENSSTAT_DATA_SHIFT)
++#define BCM2835_TS_TSENSSTAT_VALID BIT(10)
++#define BCM2835_TS_TSENSSTAT_INTERRUPT BIT(11)
++
++struct bcm2835_thermal_data {
++ struct thermal_zone_device *tz;
++ void __iomem *regs;
++ struct clk *clk;
++ struct dentry *debugfsdir;
++};
++
++static int bcm2835_thermal_adc2temp(u32 adc, int offset, int slope)
++{
++ return offset + slope * adc;
++}
++
++static int bcm2835_thermal_temp2adc(int temp, int offset, int slope)
++{
++ temp -= offset;
++ temp /= slope;
++
++ if (temp < 0)
++ temp = 0;
++ if (temp >= BIT(BCM2835_TS_TSENSSTAT_DATA_BITS))
++ temp = BIT(BCM2835_TS_TSENSSTAT_DATA_BITS) - 1;
++
++ return temp;
++}
++
++static int bcm2835_thermal_get_temp(void *d, int *temp)
++{
++ struct bcm2835_thermal_data *data = d;
++ u32 val = readl(data->regs + BCM2835_TS_TSENSSTAT);
++
++ if (!(val & BCM2835_TS_TSENSSTAT_VALID))
++ return -EIO;
++
++ val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
++
++ *temp = bcm2835_thermal_adc2temp(
++ val,
++ thermal_zone_get_offset(data->tz),
++ thermal_zone_get_slope(data->tz));
++
++ return 0;
++}
++
++static const struct debugfs_reg32 bcm2835_thermal_regs[] = {
++ {
++ .name = "ctl",
++ .offset = 0
++ },
++ {
++ .name = "stat",
++ .offset = 4
++ }
++};
++
++static void bcm2835_thermal_debugfs(struct platform_device *pdev)
++{
++ struct thermal_zone_device *tz = platform_get_drvdata(pdev);
++ struct bcm2835_thermal_data *data = tz->devdata;
++ struct debugfs_regset32 *regset;
++
++ data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL);
++ if (!data->debugfsdir)
++ return;
++
++ regset = devm_kzalloc(&pdev->dev, sizeof(*regset), GFP_KERNEL);
++ if (!regset)
++ return;
++
++ regset->regs = bcm2835_thermal_regs;
++ regset->nregs = ARRAY_SIZE(bcm2835_thermal_regs);
++ regset->base = data->regs;
++
++ debugfs_create_regset32("regset", 0444, data->debugfsdir, regset);
++}
++
++static struct thermal_zone_of_device_ops bcm2835_thermal_ops = {
++ .get_temp = bcm2835_thermal_get_temp,
++};
++
++/*
++ * Note: as per Raspberry Foundation FAQ
++ * (https://www.raspberrypi.org/help/faqs/#performanceOperatingTemperature)
++ * the recommended temperature range for the SoC -40C to +85C
++ * so the trip limit is set to 80C.
++ * this applies to all the BCM283X SoC
++ */
++
++static const struct of_device_id bcm2835_thermal_of_match_table[] = {
++ {
++ .compatible = "brcm,bcm2835-thermal",
++ },
++ {
++ .compatible = "brcm,bcm2836-thermal",
++ },
++ {
++ .compatible = "brcm,bcm2837-thermal",
++ },
++ {},
++};
++MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table);
++
++static int bcm2835_thermal_probe(struct platform_device *pdev)
++{
++ const struct of_device_id *match;
++ struct thermal_zone_device *tz;
++ struct bcm2835_thermal_data *data;
++ struct resource *res;
++ int err = 0;
++ u32 val;
++ unsigned long rate;
++
++ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
++ if (!data)
++ return -ENOMEM;
++
++ match = of_match_device(bcm2835_thermal_of_match_table,
++ &pdev->dev);
++ if (!match)
++ return -EINVAL;
++
++ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ data->regs = devm_ioremap_resource(&pdev->dev, res);
++ if (IS_ERR(data->regs)) {
++ err = PTR_ERR(data->regs);
++ dev_err(&pdev->dev, "Could not get registers: %d\n", err);
++ return err;
++ }
++
++ data->clk = devm_clk_get(&pdev->dev, NULL);
++ if (IS_ERR(data->clk)) {
++ err = PTR_ERR(data->clk);
++ if (err != -EPROBE_DEFER)
++ dev_err(&pdev->dev, "Could not get clk: %d\n", err);
++ return err;
++ }
++
++ err = clk_prepare_enable(data->clk);
++ if (err)
++ return err;
++
++ rate = clk_get_rate(data->clk);
++ if ((rate < 1920000) || (rate > 5000000))
++ dev_warn(&pdev->dev,
++ "Clock %pCn running at %pCr Hz is outside of the recommended range: 1.92 to 5MHz\n",
++ data->clk, data->clk);
++
++ /* register of thermal sensor and get info from DT */
++ tz = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
++ &bcm2835_thermal_ops);
++ if (IS_ERR(tz)) {
++ err = PTR_ERR(tz);
++ dev_err(&pdev->dev,
++ "Failed to register the thermal device: %d\n",
++ err);
++ goto err_clk;
++ }
++
++ /*
++ * right now the FW does set up the HW-block, so we are not
++ * touching the configuration registers.
++ * But if the HW is not enabled, then set it up
++ * using "sane" values used by the firmware right now.
++ */
++ val = readl(data->regs + BCM2835_TS_TSENSCTL);
++ if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
++ int trip_temp, offset, slope;
++
++ slope = thermal_zone_get_slope(tz);
++ offset = thermal_zone_get_offset(tz);
++ /*
++ * For now we deal only with critical, otherwise
++ * would need to iterate
++ */
++ err = tz->ops->get_trip_temp(tz, 0, &trip_temp);
++ if (err < 0) {
++ err = PTR_ERR(tz);
++ dev_err(&pdev->dev,
++ "Not able to read trip_temp: %d\n",
++ err);
++ goto err_tz;
++ }
++
++ /* set bandgap reference voltage and enable voltage regulator */
++ val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
++ BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
++ BCM2835_TS_TSENSCTL_REGULEN;
++
++ /* use the recommended reset duration */
++ val |= (0xFE << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
++
++ /* trip_adc value from info */
++ val |= bcm2835_thermal_temp2adc(trip_temp,
++ offset,
++ slope)
++ << BCM2835_TS_TSENSCTL_THOLD_SHIFT;
++
++ /* write the value back to the register as 2 steps */
++ writel(val, data->regs + BCM2835_TS_TSENSCTL);
++ val |= BCM2835_TS_TSENSCTL_RSTB;
++ writel(val, data->regs + BCM2835_TS_TSENSCTL);
++ }
++
++ data->tz = tz;
++
++ platform_set_drvdata(pdev, tz);
++
++ bcm2835_thermal_debugfs(pdev);
++
++ return 0;
++err_tz:
++ thermal_zone_of_sensor_unregister(&pdev->dev, tz);
++err_clk:
++ clk_disable_unprepare(data->clk);
++
++ return err;
++}
++
++static int bcm2835_thermal_remove(struct platform_device *pdev)
++{
++ struct thermal_zone_device *tz = platform_get_drvdata(pdev);
++ struct bcm2835_thermal_data *data = tz->devdata;
++
++ debugfs_remove_recursive(data->debugfsdir);
++ thermal_zone_of_sensor_unregister(&pdev->dev, tz);
++ clk_disable_unprepare(data->clk);
++
++ return 0;
++}
++
++static struct platform_driver bcm2835_thermal_driver = {
++ .probe = bcm2835_thermal_probe,
++ .remove = bcm2835_thermal_remove,
++ .driver = {
++ .name = "bcm2835_thermal",
++ .of_match_table = bcm2835_thermal_of_match_table,
++ },
++};
++module_platform_driver(bcm2835_thermal_driver);
++
++MODULE_AUTHOR("Martin Sperl");
++MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
++MODULE_LICENSE("GPL");
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