On Wed, 2016-11-02 at 10:18 +0000, kernel@xxxxxxxxxxxxxxxx wrote: > From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> > > Add basic thermal driver for bcm2835 SOC. > > This driver currently relies on the firmware setting up the > tsense HW block and does not set it up itself. > > Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> > Acked-by: Eric Anholt <eric@xxxxxxxxxx> > Acked-by: Stefan Wahren <stefan.wahren@xxxxxxxx> > Acked-by: Zhang Rui <rui.zhang@xxxxxxxxx> thanks, rui > ChangeLog: > V1 -> V2: added specific settings depending on compatiblity > added trip point based on register > setting up ctrl-register if HW is not enabled by firmware > as per recommendation of Eric (untested) > check that clock frequency is in range > (1.9 - 5MHz - as per comment in clk-bcm2835.c) > V2 -> V4: moved back to thermal (not using bcm sub-directory) > set polling interval to 1second (was 0ms, so > interrupt driven) > V5 -> V6: added correct depends in KConfig > removed defined default for RESET_DELAY > removed obvious comments > clarify HW setup comments if not set up by FW already > move clk_prepare_enable to an earlier stage and add error > handling > clarify warning when TS-clock runs out of recommended range > clk_disable_unprepare added in bcm2835_thermal_remove > added comment on recommended temperature ranges for SOC > V6 -> V7: removed depends on ARCH_BCM2836 || ARCH_BCM2837 in Kconfig > V7 -> V8: rebased > --- > drivers/thermal/Kconfig | 8 + > drivers/thermal/Makefile | 1 + > drivers/thermal/bcm2835_thermal.c | 340 > ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 349 insertions(+) > create mode 100644 drivers/thermal/bcm2835_thermal.c > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index a13541b..ab946ff 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -434,4 +434,12 @@ depends on (ARCH_QCOM && OF) || COMPILE_TEST > 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 OF > + help > + Support for thermal sensors on Broadcom bcm2835 SoCs. > + > endif > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index c92eb22..a10ebe0 100644 > --- 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 > diff --git a/drivers/thermal/bcm2835_thermal.c > b/drivers/thermal/bcm2835_thermal.c > new file mode 100644 > index 0000000..3468c7b > --- /dev/null > +++ b/drivers/thermal/bcm2835_thermal.c > @@ -0,0 +1,340 @@ > +/* > + * 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) > +#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) > +#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_info { > + int offset; > + int slope; > + int trip_temp; > +}; > + > +struct bcm2835_thermal_data { > + const struct bcm2835_thermal_info *info; > + void __iomem *regs; > + struct clk *clk; > + struct dentry *debugfsdir; > +}; > + > +static int bcm2835_thermal_adc2temp( > + const struct bcm2835_thermal_info *info, u32 adc) > +{ > + return info->offset + (adc * info->slope); > +} > + > +static int bcm2835_thermal_temp2adc( > + const struct bcm2835_thermal_info *info, int temp) > +{ > + temp -= info->offset; > + temp /= info->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_trip_type( > + struct thermal_zone_device *tz, int trip, > + enum thermal_trip_type *type) > +{ > + *type = THERMAL_TRIP_CRITICAL; > + return 0; > +} > + > +static int bcm2835_thermal_get_trip_temp( > + struct thermal_zone_device *tz, int trip, int *temp) > +{ > + struct bcm2835_thermal_data *data = tz->devdata; > + u32 val = readl(data->regs + BCM2835_TS_TSENSCTL); > + > + /* get the THOLD bits */ > + val &= BCM2835_TS_TSENSCTL_THOLD_MASK; > + val >>= BCM2835_TS_TSENSCTL_THOLD_SHIFT; > + > + /* if it is zero then use the info value */ > + if (val) > + *temp = bcm2835_thermal_adc2temp(data->info, val); > + else > + *temp = data->info->trip_temp; > + > + return 0; > +} > + > +static int bcm2835_thermal_get_temp(struct thermal_zone_device *tz, > + int *temp) > +{ > + struct bcm2835_thermal_data *data = tz->devdata; > + 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(data->info, val); > + > + 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", S_IRUGO, > + data->debugfsdir, regset); > +} > + > +static struct thermal_zone_device_ops bcm2835_thermal_ops = { > + .get_temp = bcm2835_thermal_get_temp, > + .get_trip_temp = bcm2835_thermal_get_trip_temp, > + .get_trip_type = bcm2835_thermal_get_trip_type, > +}; > + > +static const struct of_device_id 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; > + 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; > + data->info = match->data; > + > + 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); > + > + /* > + * 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)) { > + /* the basic required flags */ > + val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT << > + BCM2835_TS_TSENSCTL_CTRL_SHIFT) | > + BCM2835_TS_TSENSCTL_REGULEN; > + > + /* > + * reset delay using the current firmware value of > 14 > + * - units of time are unknown. > + */ > + val |= (14 << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT); > + > + /* trip_adc value from info */ > + val |= bcm2835_thermal_temp2adc(data->info, > + data->info- > >trip_temp) << > + 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); > + } > + > + /* register thermal zone with 1 trip point an 1s polling */ > + tz = thermal_zone_device_register("bcm2835_thermal", > + 1, 0, data, > + &bcm2835_thermal_ops, > + NULL, > + 0, 1000); > + if (IS_ERR(tz)) { > + clk_disable_unprepare(data->clk); > + err = PTR_ERR(tz); > + dev_err(&pdev->dev, > + "Failed to register the thermal device: > %d\n", > + err); > + return err; > + } > + > + platform_set_drvdata(pdev, tz); > + > + bcm2835_thermal_debugfs(pdev); > + > + return 0; > +} > + > +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_device_unregister(tz); > + clk_disable_unprepare(data->clk); > + > + return 0; > +} > + > +/* > + * Note: as per Raspberry Foundation FAQ > + * (https://www.raspberrypi.org/help/faqs/#performanceOperatingTempe > rature) > + * 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", > + .data = &(struct bcm2835_thermal_info) { > + .offset = 407000, > + .slope = -538, > + .trip_temp = 80000 > + } > + }, > + { > + .compatible = "brcm,bcm2836-thermal", > + .data = &(struct bcm2835_thermal_info) { > + .offset = 407000, > + .slope = -538, > + .trip_temp = 80000 > + } > + }, > + { > + .compatible = "brcm,bcm2837-thermal", > + .data = &(struct bcm2835_thermal_info) { > + /* the bcm2837 needs adjustment of +5C */ > + .offset = 407000 + 5000, > + .slope = -538, > + .trip_temp = 80000 > + } > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table); > + > +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"); > -- > 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html