[V9] thermal: bcm2835: add thermal driver for bcm2835 soc

Message ID	1483808145-6206-1-git-send-email-kernel@martin.sperl.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: kernel@martin.sperl.org To: Zhang Rui <rui.zhang@intel.com>, Eduardo Valentin <edubezval@gmail.com>, Lee Jones <lee@kernel.org>, Eric Anholt <eric@anholt.net>, linux-pm@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V9] thermal: bcm2835: add thermal driver for bcm2835 soc Date: Sat, 7 Jan 2017 16:55:45 +0000 Message-Id: <1483808145-6206-1-git-send-email-kernel@martin.sperl.org> Precedence: list Cc: Martin Sperl <kernel@martin.sperl.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index c2c056c..18f2de6 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -436,4 +436,12 @@ 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 6a3d7b5..677c6d9 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -56,3 +56,4 @@ 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..5e2fea9 --- /dev/null +++ b/drivers/thermal/bcm2835_thermal.c @@ -0,0 +1,354 @@ +/* + * 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(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_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( + val, + thermal_zone_get_offset(tz), + thermal_zone_get_slope(tz)); + 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( + val, + thermal_zone_get_offset(tz), + thermal_zone_get_slope(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", 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 thermal_zone_params *tzp; + const struct bcm2835_thermal_info *ti; + 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; + + tzp = devm_kzalloc(&pdev->dev, sizeof(*tzp), GFP_KERNEL); + if (!data) + return -ENOMEM; + + match = of_match_device(bcm2835_thermal_of_match_table, + &pdev->dev); + if (!match) + return -EINVAL; + ti = match->data; + data->info = ti; + tzp->slope = ti->slope; + tzp->offset = ti->offset; + + 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->trip_temp, + data->info->offset, + data->info->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); + } + + /* register thermal zone with 1 trip point an 1s polling */ + tz = thermal_zone_device_register("bcm2835_thermal", + 1, 0, data, + &bcm2835_thermal_ops, + tzp, + 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/#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", + .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");

[V9] thermal: bcm2835: add thermal driver for bcm2835 soc

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