From patchwork Sat Jan 7 16:55:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Sperl X-Patchwork-Id: 9503231 X-Patchwork-Delegate: eduardo.valentin@ti.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 104C6606DE for ; Sat, 7 Jan 2017 17:56:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 029E8284B0 for ; Sat, 7 Jan 2017 17:56:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E7871284C5; Sat, 7 Jan 2017 17:56:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 82E52284B0 for ; Sat, 7 Jan 2017 17:56:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941545AbdAGRz7 (ORCPT ); Sat, 7 Jan 2017 12:55:59 -0500 Received: from 212-186-180-163.static.upcbusiness.at ([212.186.180.163]:47184 "EHLO cgate.sperl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941508AbdAGRz6 (ORCPT ); Sat, 7 Jan 2017 12:55:58 -0500 X-Greylist: delayed 3602 seconds by postgrey-1.27 at vger.kernel.org; Sat, 07 Jan 2017 12:55:57 EST Received: from rasp3a.intern.sperl.org (account martin@sperl.org [10.10.10.43] verified) by sperl.org (CommuniGate Pro SMTP 6.1.11) with ESMTPSA id 6944951; Sat, 07 Jan 2017 16:55:52 +0000 From: kernel@martin.sperl.org To: Zhang Rui , Eduardo Valentin , Lee Jones , Eric Anholt , linux-pm@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Cc: Martin Sperl 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> X-Mailer: git-send-email 2.1.4 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Martin Sperl 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 Acked-by: Eric Anholt Acked-by: Stefan Wahren --- drivers/thermal/Kconfig | 8 + drivers/thermal/Makefile | 1 + drivers/thermal/bcm2835_thermal.c | 354 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 363 insertions(+) create mode 100644 drivers/thermal/bcm2835_thermal.c 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 V8 -> V9: moved to use the thermal framework offset and slope in thermal_zone_parameters as per request A few additional notes on this latest patch: * all the other portions of the patch (dt, bindings, defconf) have already been merged into 4.10.0-rc2 - this only leaves the driver itself which is now just a single patch to get applied. * the driver has been moved to use thermal_zone_parameters->offset and slope making use of the thermal_zone_get_offset and thermal_zone_get_slope methods where relevant Note that we cannot use those during initial setup of the HW - this code section is typically not used anyway, as the FW sets up the device already. This so modified patch actually increases code size by 14 lines: drivers/thermal/bcm2835_thermal.c | 42 ++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 14 deletions(-) * /sys/class/thermal/*/ contains now slope and offset files and those expose the correct values * for some reason on module load the kernel emits now the message: (NULL device *): hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info(). But this seems framework specific and needs to get addressed there. -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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");