From patchwork Wed Dec 14 13:35:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bough Chen X-Patchwork-Id: 13073197 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 03553C4332F for ; Wed, 14 Dec 2022 14:00:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:Subject:Cc:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=nDvfNmwyQ/x1Llv2F+kVKw8M+8PO2qzOnEU/AjTTVZM=; b=GS9E1vXrJvHtQt pTKZlNITCfDofKKUYOrMkeYgautlwDluDVwaWIx4sdzGaKhU6tXbXAgtmC6vUvL6AZN9B2yc/GUet 329VnwDRNYtn+WTP0J9rX/CtlIoMGpPCGbcHvVC6LIaM+YLs4xGfu3uFdVkf1Vl2Ik54/56EeqinY EbKY4AzWe8RJu70CmwBYmfbkhSsNSPc/5MQZ2o+BwlrWvfo0qEarxaJmp5MK32uDEE3D1cfWfx7Iz jt+8PceFeQ8Nfw92kaeOssPGuTNF/dhsuGLvfqhCL1VfILw7nVLXnDT/JBHmZNROQpnHilguWy6/p JaF4jja30iA9kERsS8rw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p5SHr-00H2Z4-Mo; Wed, 14 Dec 2022 13:59:07 +0000 Received: from inva020.nxp.com ([92.121.34.13]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p5SHY-00H2OB-En for linux-arm-kernel@lists.infradead.org; Wed, 14 Dec 2022 13:58:51 +0000 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 991901A1864; Wed, 14 Dec 2022 14:58:41 +0100 (CET) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 3672F1A1860; Wed, 14 Dec 2022 14:58:41 +0100 (CET) Received: from local (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id 977F0180219B; Wed, 14 Dec 2022 21:58:39 +0800 (+08) From: haibo.chen@nxp.com To: jic23@kernel.org, lars@metafoo.de, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de Cc: festevam@gmail.com, linux-imx@nxp.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, haibo.chen@nxp.com Subject: [PATCH v2 1/3] iio: adc: add imx93 adc support Date: Wed, 14 Dec 2022 21:35:37 +0800 Message-Id: <1671024939-29322-1-git-send-email-haibo.chen@nxp.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221214_055848_933729_D9D03344 X-CRM114-Status: GOOD ( 28.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Haibo Chen The ADC in i.mx93 is a total new ADC IP, add a driver to support this ADC. Currently, only support one shot normal conversion triggered by software. For other mode, will add in future. Signed-off-by: Haibo Chen --- MAINTAINERS | 4 +- drivers/iio/adc/Kconfig | 10 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/imx93_adc.c | 474 ++++++++++++++++++++++++++++++++++++ 4 files changed, 488 insertions(+), 1 deletion(-) create mode 100644 drivers/iio/adc/imx93_adc.c diff --git a/MAINTAINERS b/MAINTAINERS index 3274b6db8be9..786c30bba19a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15020,14 +15020,16 @@ S: Maintained F: Documentation/devicetree/bindings/iio/adc/nxp,imx8qxp-adc.yaml F: drivers/iio/adc/imx8qxp-adc.c -NXP i.MX 7D/6SX/6UL AND VF610 ADC DRIVER +NXP i.MX 7D/6SX/6UL/93 AND VF610 ADC DRIVER M: Haibo Chen L: linux-iio@vger.kernel.org L: linux-imx@nxp.com S: Maintained F: Documentation/devicetree/bindings/iio/adc/fsl,imx7d-adc.yaml F: Documentation/devicetree/bindings/iio/adc/fsl,vf610-adc.yaml +F: Documentation/devicetree/bindings/iio/adc/nxp,imx93-adc.yaml F: drivers/iio/adc/imx7d_adc.c +F: drivers/iio/adc/imx93_adc.c F: drivers/iio/adc/vf610_adc.c NXP PF8100/PF8121A/PF8200 PMIC REGULATOR DEVICE DRIVER diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 46c4fc2fc534..4fc826f52b8c 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -565,6 +565,16 @@ config IMX8QXP_ADC This driver can also be built as a module. If so, the module will be called imx8qxp-adc. +config IMX93_ADC + tristate "IMX93 ADC driver" + depends on ARCH_MXC || COMPILE_TEST + depends on HAS_IOMEM + help + Say yes here to build support for IMX93 ADC. + + This driver can also be built as a module. If so, the module will be + called imx93_adc. + config LP8788_ADC tristate "LP8788 ADC driver" depends on MFD_LP8788 diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 6e08415c3f3a..df8c0f26307d 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -49,6 +49,7 @@ obj-$(CONFIG_HI8435) += hi8435.o obj-$(CONFIG_HX711) += hx711.o obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o obj-$(CONFIG_IMX8QXP_ADC) += imx8qxp-adc.o +obj-$(CONFIG_IMX93_ADC) += imx93_adc.o obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o obj-$(CONFIG_INGENIC_ADC) += ingenic-adc.o obj-$(CONFIG_INTEL_MRFLD_ADC) += intel_mrfld_adc.o diff --git a/drivers/iio/adc/imx93_adc.c b/drivers/iio/adc/imx93_adc.c new file mode 100644 index 000000000000..3ea16a70e746 --- /dev/null +++ b/drivers/iio/adc/imx93_adc.c @@ -0,0 +1,474 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * NXP i.MX93 ADC driver + * + * Copyright 2022 NXP + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define IMX93_ADC_DRIVER_NAME "imx93-adc" + +/* Register map definition */ +#define IMX93_ADC_MCR 0x00 +#define IMX93_ADC_MSR 0x04 +#define IMX93_ADC_ISR 0x10 +#define IMX93_ADC_IMR 0x20 +#define IMX93_ADC_CIMR0 0x24 +#define IMX93_ADC_CTR0 0x94 +#define IMX93_ADC_NCMR0 0xA4 +#define IMX93_ADC_PCDR0 0x100 +#define IMX93_ADC_PCDR1 0x104 +#define IMX93_ADC_PCDR2 0x108 +#define IMX93_ADC_PCDR3 0x10c +#define IMX93_ADC_PCDR4 0x110 +#define IMX93_ADC_PCDR5 0x114 +#define IMX93_ADC_PCDR6 0x118 +#define IMX93_ADC_PCDR7 0x11c +#define IMX93_ADC_CALSTAT 0x39C + +/* ADC bit shift */ +#define IMX93_ADC_MCR_MODE_MASK BIT(29) +#define IMX93_ADC_MCR_NSTART_MASK BIT(24) +#define IMX93_ADC_MCR_CALSTART_MASK BIT(14) +#define IMX93_ADC_MCR_ADCLKSE_MASK BIT(8) +#define IMX93_ADC_MCR_PWDN_MASK BIT(0) +#define IMX93_ADC_MSR_CALFAIL_MASK BIT(30) +#define IMX93_ADC_MSR_CALBUSY_MASK BIT(29) +#define IMX93_ADC_MSR_ADCSTATUS_MASK GENMASK(2, 0) +#define IMX93_ADC_ISR_ECH_MASK BIT(0) +#define IMX93_ADC_ISR_EOC_MASK BIT(1) +#define IMX93_ADC_ISR_EOC_ECH_MASK (IMX93_ADC_ISR_EOC_MASK | \ + IMX93_ADC_ISR_ECH_MASK) +#define IMX93_ADC_IMR_JEOC_MASK BIT(3) +#define IMX93_ADC_IMR_JECH_MASK BIT(2) +#define IMX93_ADC_IMR_EOC_MASK BIT(1) +#define IMX93_ADC_IMR_ECH_MASK BIT(0) +#define IMX93_ADC_PCDR_CDATA_MASK GENMASK(11, 0) + +/* ADC status */ +#define IMX93_ADC_IDLE 0 +#define IMX93_ADC_POWER_DOWN 1 +#define IMX93_ADC_WAIT_STATE 2 +#define IMX93_ADC_BUSY_IN_CALIBRATION 3 +#define IMX93_ADC_SAMPLE 4 +#define IMX93_ADC_CONVERSION 6 + +#define IMX93_ADC_TIMEOUT msecs_to_jiffies(100) + +struct imx93_adc { + struct device *dev; + void __iomem *regs; + struct clk *ipg_clk; + int irq; + struct regulator *vref; + /* lock to protect against multiple access to the device */ + struct mutex lock; + struct completion completion; +}; + +#define IMX93_ADC_CHAN(_idx) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (_idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ +} + +static const struct iio_chan_spec imx93_adc_iio_channels[] = { + IMX93_ADC_CHAN(0), + IMX93_ADC_CHAN(1), + IMX93_ADC_CHAN(2), + IMX93_ADC_CHAN(3), +}; + +static void imx93_adc_power_down(struct imx93_adc *adc) +{ + u32 mcr, msr; + int ret; + + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr |= FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); + + ret = readl_poll_timeout(adc->regs + IMX93_ADC_MSR, msr, + ((msr & IMX93_ADC_MSR_ADCSTATUS_MASK) == IMX93_ADC_POWER_DOWN), 1, 50); + if (ret == -ETIMEDOUT) + dev_warn(adc->dev, + "ADC do not in power down mode, current MSR is %x\n", + msr); +} + +static void imx93_adc_power_up(struct imx93_adc *adc) +{ + u32 mcr; + + /* bring ADC out of power down state, in idle state */ + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr &= ~FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); +} + +static void imx93_adc_config_ad_clk(struct imx93_adc *adc) +{ + u32 mcr; + + /* put adc in power down mode */ + imx93_adc_power_down(adc); + + /* config the AD_CLK equal to bus clock */ + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr |= FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); + + imx93_adc_power_up(adc); +} + +static int imx93_adc_calibration(struct imx93_adc *adc) +{ + u32 mcr, msr; + int ret; + + /* make sure ADC in power down mode */ + imx93_adc_power_down(adc); + + /* config SAR controller operating clock */ + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr &= ~FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); + + imx93_adc_power_up(adc); + + /* + * TODO: we use the default TSAMP/NRSMPL/AVGEN in MCR, + * can add the setting of these bit if need in future. + */ + + /* run calibration */ + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr |= FIELD_PREP(IMX93_ADC_MCR_CALSTART_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); + + /* wait calibration to be finished */ + ret = readl_poll_timeout(adc->regs + IMX93_ADC_MSR, msr, + !(msr & IMX93_ADC_MSR_CALBUSY_MASK), 1000, 2000000); + if (ret == -ETIMEDOUT) { + dev_warn(adc->dev, "ADC do not finish calibration in 1 min!\n"); + return ret; + } + + /* check whether calbration is success or not */ + msr = readl(adc->regs + IMX93_ADC_MSR); + if (msr & IMX93_ADC_MSR_CALFAIL_MASK) { + dev_warn(adc->dev, "ADC calibration failed!\n"); + return -EAGAIN; + } + + return 0; +} + +static int imx93_adc_read_channel_conversion(struct imx93_adc *adc, + int channel_number, + int *result) +{ + u32 channel; + u32 imr, mcr, pcda; + long ret; + + reinit_completion(&adc->completion); + + /* config channel mask register */ + channel = 1 << channel_number; + writel(channel, adc->regs + IMX93_ADC_NCMR0); + + /* TODO: can config desired sample time in CTRn if need */ + + /* config interrupt mask */ + imr = FIELD_PREP(IMX93_ADC_IMR_EOC_MASK, 1); + writel(imr, adc->regs + IMX93_ADC_IMR); + writel(channel, adc->regs + IMX93_ADC_CIMR0); + + /* config one-shot mode */ + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr &= ~FIELD_PREP(IMX93_ADC_MCR_MODE_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); + + /* start normal conversion */ + mcr = readl(adc->regs + IMX93_ADC_MCR); + mcr |= FIELD_PREP(IMX93_ADC_MCR_NSTART_MASK, 1); + writel(mcr, adc->regs + IMX93_ADC_MCR); + + ret = wait_for_completion_interruptible_timeout(&adc->completion, + IMX93_ADC_TIMEOUT); + if (ret == 0) + return -ETIMEDOUT; + + if (ret < 0) + return ret; + + pcda = readl(adc->regs + IMX93_ADC_PCDR0 + channel_number * 4); + + *result = FIELD_GET(IMX93_ADC_PCDR_CDATA_MASK, pcda); + + return ret; +} + +static int imx93_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct imx93_adc *adc = iio_priv(indio_dev); + struct device *dev = adc->dev; + long ret; + u32 vref_uv; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + pm_runtime_get_sync(dev); + mutex_lock(&adc->lock); + ret = imx93_adc_read_channel_conversion(adc, chan->channel, val); + mutex_unlock(&adc->lock); + pm_runtime_mark_last_busy(dev); + pm_runtime_put_sync_autosuspend(dev); + if (ret > 0) + return IIO_VAL_INT; + else + return ret; + + case IIO_CHAN_INFO_SCALE: + ret = vref_uv = regulator_get_voltage(adc->vref); + if (ret < 0) + return ret; + *val = vref_uv / 1000; + *val2 = 12; + return IIO_VAL_FRACTIONAL_LOG2; + + case IIO_CHAN_INFO_SAMP_FREQ: + *val = clk_get_rate(adc->ipg_clk); + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static irqreturn_t imx93_adc_isr(int irq, void *dev_id) +{ + struct imx93_adc *adc = dev_id; + u32 isr, eoc, unexpected; + + isr = readl(adc->regs + IMX93_ADC_ISR); + + if (FIELD_GET(IMX93_ADC_ISR_EOC_ECH_MASK, isr)) { + eoc = isr & IMX93_ADC_ISR_EOC_ECH_MASK; + writel(eoc, adc->regs + IMX93_ADC_ISR); + complete(&adc->completion); + } + + unexpected = isr & ~IMX93_ADC_ISR_EOC_ECH_MASK; + if (unexpected) { + writel(unexpected, adc->regs + IMX93_ADC_ISR); + dev_err(adc->dev, "Unexpected interrupt 0x%08x.\n", unexpected); + return IRQ_NONE; + } + + return IRQ_HANDLED; +} + +static const struct iio_info imx93_adc_iio_info = { + .read_raw = &imx93_adc_read_raw, +}; + +static int imx93_adc_probe(struct platform_device *pdev) +{ + struct imx93_adc *adc; + struct iio_dev *indio_dev; + struct device *dev = &pdev->dev; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!indio_dev) { + dev_err(dev, "Failed allocating iio device\n"); + return -ENOMEM; + } + + adc = iio_priv(indio_dev); + adc->dev = dev; + + mutex_init(&adc->lock); + adc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(adc->regs)) + return PTR_ERR(adc->regs); + + /* The third irq is for ADC conversion usage */ + adc->irq = platform_get_irq(pdev, 2); + if (adc->irq < 0) + return adc->irq; + + adc->ipg_clk = devm_clk_get(dev, "ipg"); + if (IS_ERR(adc->ipg_clk)) + return dev_err_probe(dev, PTR_ERR(adc->ipg_clk), + "Failed getting clock.\n"); + + adc->vref = devm_regulator_get(dev, "vref"); + if (IS_ERR(adc->vref)) + return dev_err_probe(dev, PTR_ERR(adc->vref), + "Failed getting reference voltage.\n"); + + ret = regulator_enable(adc->vref); + if (ret) { + dev_err(dev, "Can't enable adc reference top voltage.\n"); + return ret; + } + + platform_set_drvdata(pdev, indio_dev); + + init_completion(&adc->completion); + + indio_dev->name = IMX93_ADC_DRIVER_NAME; + indio_dev->info = &imx93_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = imx93_adc_iio_channels; + indio_dev->num_channels = ARRAY_SIZE(imx93_adc_iio_channels); + + ret = clk_prepare_enable(adc->ipg_clk); + if (ret) { + dev_err(&pdev->dev, "Could not prepare or enable the clock.\n"); + goto error_regulator_disable; + } + + ret = request_irq(adc->irq, imx93_adc_isr, 0, IMX93_ADC_DRIVER_NAME, adc); + if (ret < 0) { + dev_err(dev, "Failed requesting irq, irq = %d\n", adc->irq); + goto error_ipg_clk_disable; + } + + ret = imx93_adc_calibration(adc); + if (ret < 0) + goto error_free_adc_irq; + + imx93_adc_config_ad_clk(adc); + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(dev, "Couldn't register the device.\n"); + goto error_free_adc_irq; + } + + pm_runtime_set_active(dev); + pm_runtime_set_autosuspend_delay(dev, 50); + pm_runtime_use_autosuspend(dev); + pm_runtime_enable(dev); + + return 0; + +error_free_adc_irq: + free_irq(adc->irq, adc); +error_ipg_clk_disable: + clk_disable_unprepare(adc->ipg_clk); +error_regulator_disable: + regulator_disable(adc->vref); + + return ret; +} + +static int imx93_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct imx93_adc *adc = iio_priv(indio_dev); + struct device *dev = adc->dev; + + /* adc power down need clock on */ + pm_runtime_get_sync(dev); + imx93_adc_power_down(adc); + + pm_runtime_disable(dev); + pm_runtime_put_noidle(dev); + iio_device_unregister(indio_dev); + free_irq(adc->irq, adc); + clk_disable_unprepare(adc->ipg_clk); + regulator_disable(adc->vref); + + return 0; +} + +static int imx93_adc_runtime_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct imx93_adc *adc = iio_priv(indio_dev); + + imx93_adc_power_down(adc); + clk_disable_unprepare(adc->ipg_clk); + regulator_disable(adc->vref); + + return 0; +} + +static int imx93_adc_runtime_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct imx93_adc *adc = iio_priv(indio_dev); + int ret; + + ret = regulator_enable(adc->vref); + if (ret) { + dev_err(dev, + "Can't enable adc reference top voltage, err = %d\n", + ret); + return ret; + } + + ret = clk_prepare_enable(adc->ipg_clk); + if (ret) { + dev_err(dev, "Could not prepare or enable clock.\n"); + goto err_disable_reg; + } + + imx93_adc_power_up(adc); + + return 0; + +err_disable_reg: + regulator_disable(adc->vref); + + return ret; +} + +static DEFINE_RUNTIME_DEV_PM_OPS(imx93_adc_pm_ops, + imx93_adc_runtime_suspend, + imx93_adc_runtime_resume, NULL); + +static const struct of_device_id imx93_adc_match[] = { + { .compatible = "nxp,imx93-adc", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, imx93_adc_match); + +static struct platform_driver imx93_adc_driver = { + .probe = imx93_adc_probe, + .remove = imx93_adc_remove, + .driver = { + .name = IMX93_ADC_DRIVER_NAME, + .of_match_table = imx93_adc_match, + .pm = pm_ptr(&imx93_adc_pm_ops), + }, +}; + +module_platform_driver(imx93_adc_driver); + +MODULE_DESCRIPTION("NXP i.MX93 ADC driver"); +MODULE_AUTHOR("Haibo Chen "); +MODULE_LICENSE("GPL");