/branches/gl-inet/target/linux/generic/backport-4.9/081-0001-thermal-bcm2835-add-thermal-driver-for-bcm2835-SoC.patch |
@@ -0,0 +1,365 @@ |
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 |
@@ -434,4 +434,12 @@ depends on (ARCH_QCOM && OF) || COMPILE_ |
source "drivers/thermal/qcom/Kconfig" |
endmenu |
|
+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 |
@@ -55,3 +55,4 @@ obj-$(CONFIG_TEGRA_SOCTHERM) += tegra/ |
obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o |
obj-$(CONFIG_MTK_THERMAL) += mtk_thermal.o |
obj-$(CONFIG_GENERIC_ADC_THERMAL) += thermal-generic-adc.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"); |