From patchwork Wed Sep 21 08:23:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Sperl X-Patchwork-Id: 9343029 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 5238F607D0 for ; Wed, 21 Sep 2016 08:26:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 401322A2FA for ; Wed, 21 Sep 2016 08:26:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 348A92A2FC; Wed, 21 Sep 2016 08:26:40 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5D26A2A2FA for ; Wed, 21 Sep 2016 08:26:39 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bmcqC-0004N9-PR; Wed, 21 Sep 2016 08:25:16 +0000 Received: from 212-186-180-163.static.upcbusiness.at ([212.186.180.163] helo=cgate.sperl.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bmcpJ-0003Kr-Jo; Wed, 21 Sep 2016 08:24:25 +0000 Received: from rasp3a.intern.sperl.org (account martin@sperl.org [10.10.10.43] verified) by sperl.org (CommuniGate Pro SMTP 6.1.2) with ESMTPSA id 6670871; Wed, 21 Sep 2016 08:23:52 +0000 From: kernel@martin.sperl.org To: Zhang Rui , Eduardo Valentin , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Lee Jones , Eric Anholt , Russell King , Florian Fainelli , Catalin Marinas , Will Deacon , Stefan Wahren , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V7 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc Date: Wed, 21 Sep 2016 08:23:43 +0000 Message-Id: <1474446227-1147-3-git-send-email-kernel@martin.sperl.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1474446227-1147-1-git-send-email-kernel@martin.sperl.org> References: <1474446227-1147-1-git-send-email-kernel@martin.sperl.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160921_012422_098893_AB7344FE X-CRM114-Status: GOOD ( 26.30 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Martin Sperl MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 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 --- 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 2d702ca..1bc8b14 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -399,4 +399,12 @@ config GENERIC_ADC_THERMAL to this driver. This driver reports the temperature by reading ADC channel and converts it to temperature based on lookup table. +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 10b07c1..c26343e 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -51,3 +51,4 @@ 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 +#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( + 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/#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");