+++ /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
-@@ -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");
projects / openwrt / staging / dedeckeh.git / blobdiff