TI中文支持网Part Number:AM3354
你好，我是用335xd的核心板，你们的adc采集，AIN0-6都正常，AIN7在采集时，会偶尔出现很大的负值，而且每次都是固定值-550525552，请问可能是什么原因，要怎么排查
Nancy Wang：
请问AIN7输入信号是正常的吗？电压是多少？
另外请贴出您使用的SDK版本以及ADC设备树部分的配置。
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user6044729：
电压范围是正常的0-1.8V ，我不清楚sdk，而且内核是linux3.2，不是设备树的，是板级文件，下面是ti_adc.c的驱动
/** TI ADC MFD driver** Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/** 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 version 2.** This program is distributed "as is" WITHOUT ANY WARRANTY of any* kind, whether express or implied; without even the implied warranty* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the* GNU General Public License for more details.*/#include <linux/init.h> #include <linux/kernel.h> #include <linux/err.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/io.h> #include <linux/sched.h>#include "../iio.h" #include "../sysfs.h" #include "../buffer_generic.h" #include "../ring_sw.h"#include <linux/mfd/ti_tscadc.h> #include <linux/platform_data/ti_adc.h>struct adc_device {struct ti_tscadc_dev *mfd_tscadc;struct iio_dev*idev;struct work_struct poll_work;wait_queue_head_t wq_data_avail;intchannels;intirq;boolis_continuous_mode;u16*buffer; };static unsigned int adc_readl(struct adc_device *adc, unsigned int reg) {return readl(adc->mfd_tscadc->tscadc_base + reg); }static void adc_writel(struct adc_device *adc, unsigned int reg,unsigned int val) {writel(val, adc->mfd_tscadc->tscadc_base + reg); }static void adc_step_config(struct adc_device *adc_dev, bool mode) {unsigned intstepconfig;int i, channels = 0, steps;/** There are 16 configurable steps and 8 analog input* lines available which are shared between Touchscreen and ADC.** Steps backwards i.e. from 16 towards 0 are used by ADC* depending on number of input lines needed.* Channel would represent which analog input* needs to be given to ADC to digitalize data.*/steps = TOTAL_STEPS - adc_dev->channels;channels = TOTAL_CHANNELS - adc_dev->channels;if (mode == 0)stepconfig = TSCADC_STEPCONFIG_AVG_16 | TSCADC_STEPCONFIG_FIFO1;elsestepconfig = TSCADC_STEPCONFIG_AVG_16 | TSCADC_STEPCONFIG_FIFO1| TSCADC_STEPCONFIG_MODE_SWCNT;for (i = (steps + 1); i <= TOTAL_STEPS; i++) {adc_writel(adc_dev, TSCADC_REG_STEPCONFIG(i),stepconfig | TSCADC_STEPCONFIG_INP(channels));adc_writel(adc_dev, TSCADC_REG_STEPDELAY(i),TSCADC_STEPCONFIG_OPENDLY);channels++;} }static ssize_t tiadc_show_mode(struct device *dev,struct device_attribute *attr, char *buf) {struct iio_dev *indio_dev = dev_get_drvdata(dev);struct adc_device *adc_dev = iio_priv(indio_dev);unsigned int tmp;tmp = adc_readl(adc_dev, TSCADC_REG_STEPCONFIG(TOTAL_STEPS));tmp &= TSCADC_STEPCONFIG_MODE(1);if (tmp == 0x00)return sprintf(buf, "oneshot\n");else if (tmp == 0x01)return sprintf(buf, "continuous\n");elsereturn sprintf(buf, "Operation mode unknown\n"); }static ssize_t tiadc_set_mode(struct device *dev,struct device_attribute *attr, const char *buf, size_t count) {struct iio_dev *indio_dev = dev_get_drvdata(dev);struct adc_device *adc_dev = iio_priv(indio_dev);unsigned int config;config = adc_readl(adc_dev, TSCADC_REG_CTRL);config &= ~(TSCADC_CNTRLREG_TSCSSENB);adc_writel(adc_dev, TSCADC_REG_CTRL, config);if (!strncmp(buf, "oneshot", 7))adc_dev->is_continuous_mode = false;else if (!strncmp(buf, "continuous", 10))adc_dev->is_continuous_mode = true;else {dev_err(dev, "Operational mode unknown\n");return -EINVAL;}adc_step_config(adc_dev, adc_dev->is_continuous_mode);config = adc_readl(adc_dev, TSCADC_REG_CTRL);adc_writel(adc_dev, TSCADC_REG_CTRL,(config | TSCADC_CNTRLREG_TSCSSENB));return count; }static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, tiadc_show_mode,tiadc_set_mode, 0);static struct attribute *tiadc_attributes[] = {&iio_dev_attr_mode.dev_attr.attr,NULL, };static const struct attribute_group tiadc_attribute_group = {.attrs = tiadc_attributes, };static irqreturn_t tiadc_irq(int irq, void *private) {struct iio_dev *idev = private;struct adc_device *adc_dev = iio_priv(idev);unsigned int status, config;status = adc_readl(adc_dev, TSCADC_REG_IRQSTATUS);if (status & TSCADC_IRQENB_FIFO1OVRRUN) {config = adc_readl(adc_dev, TSCADC_REG_CTRL);config &= ~(TSCADC_CNTRLREG_TSCSSENB);adc_writel(adc_dev, TSCADC_REG_CTRL, config);adc_writel(adc_dev, TSCADC_REG_IRQSTATUS,TSCADC_IRQENB_FIFO1OVRRUN |TSCADC_IRQENB_FIFO1UNDRFLW |TSCADC_IRQENB_FIFO1THRES);adc_writel(adc_dev, TSCADC_REG_CTRL,(config | TSCADC_CNTRLREG_TSCSSENB));return IRQ_HANDLED;} else if (status & TSCADC_IRQENB_FIFO1THRES) {adc_writel(adc_dev, TSCADC_REG_IRQCLR,TSCADC_IRQENB_FIFO1THRES);if (iio_buffer_enabled(idev)) {if (!work_pending(&adc_dev->poll_work))schedule_work(&adc_dev->poll_work);} else {wake_up_interruptible(&adc_dev->wq_data_avail);}return IRQ_HANDLED;} else {return IRQ_NONE;} }static void tiadc_poll_handler(struct work_struct *work_s) {struct adc_device *adc_dev =container_of(work_s, struct adc_device, poll_work);struct iio_dev *idev = iio_priv_to_dev(adc_dev);struct iio_buffer *buffer = idev->buffer;unsigned int fifo1count, readx1;int i;u32 *iBuf;fifo1count = adc_readl(adc_dev, TSCADC_REG_FIFO1CNT);if (fifo1count * sizeof(u32) <buffer->access->get_bytes_per_datum(buffer)) {dev_err(adc_dev->mfd_tscadc->dev, "%s: Short FIFO event\n",__func__);goto out;}iBuf = kmalloc(fifo1count * sizeof(u32), GFP_KERNEL);if (iBuf == NULL)goto out;for (i = 0; i < fifo1count; i++) {readx1 = adc_readl(adc_dev, TSCADC_REG_FIFO1);readx1 &= TSCADC_FIFOREAD_DATA_MASK;iBuf[i] = readx1;}buffer->access->store_to(buffer, (u8 *) iBuf, iio_get_time_ns());kfree(iBuf);out:adc_writel(adc_dev, TSCADC_REG_IRQSTATUS,TSCADC_IRQENB_FIFO1THRES);adc_writel(adc_dev, TSCADC_REG_IRQENABLE,TSCADC_IRQENB_FIFO1THRES); }static int tiadc_buffer_preenable(struct iio_dev *idev) {struct iio_buffer *buffer = idev->buffer;buffer->access->set_bytes_per_datum(buffer, 16);return 0; }static int tiadc_buffer_postenable(struct iio_dev *idev) {struct adc_device *adc_dev = iio_priv(idev);struct iio_buffer *buffer = idev->buffer;unsigned int enb, config;int stepnum;u8 bit;if (!adc_dev->is_continuous_mode) {pr_info("Data cannot be read continuously in one shot mode\n");return -EINVAL;} else {config = adc_readl(adc_dev, TSCADC_REG_CTRL);adc_writel(adc_dev, TSCADC_REG_CTRL,config & ~TSCADC_CNTRLREG_TSCSSENB);adc_writel(adc_dev, TSCADC_REG_CTRL,config | TSCADC_CNTRLREG_TSCSSENB);adc_writel(adc_dev, TSCADC_REG_IRQSTATUS,TSCADC_IRQENB_FIFO1THRES |TSCADC_IRQENB_FIFO1OVRRUN |TSCADC_IRQENB_FIFO1UNDRFLW);adc_writel(adc_dev, TSCADC_REG_IRQENABLE,TSCADC_IRQENB_FIFO1THRES |TSCADC_IRQENB_FIFO1OVRRUN);adc_writel(adc_dev, TSCADC_REG_SE, 0x00);for_each_set_bit(bit, buffer->scan_mask,adc_dev->channels) {struct iio_chan_spec const *chan = idev->channels + bit;/** There are a total of 16 steps available* that are shared between ADC and touchscreen.* We start configuring from step 16 to 0 incase of* ADC. Hence the relation between input channel* and step for ADC would be as below.*/stepnum = chan->channel + 9;enb = adc_readl(adc_dev, TSCADC_REG_SE);enb |= (1 << stepnum);adc_writel(adc_dev, TSCADC_REG_SE, enb);}return 0;} }static int tiadc_buffer_postdisable(struct iio_dev *idev) {struct adc_device *adc_dev = iio_priv(idev);adc_writel(adc_dev, TSCADC_REG_IRQCLR, (TSCADC_IRQENB_FIFO1THRES |TSCADC_IRQENB_FIFO1OVRRUN |TSCADC_IRQENB_FIFO1UNDRFLW));adc_writel(adc_dev, TSCADC_REG_SE, TSCADC_STPENB_STEPENB_TC);return 0; }static const struct iio_buffer_setup_ops tiadc_swring_setup_ops = {.preenable = &tiadc_buffer_preenable,.postenable = &tiadc_buffer_postenable,.postdisable = &tiadc_buffer_postdisable, };static int tiadc_config_sw_ring(struct iio_dev *idev) {struct adc_device *adc_dev = iio_priv(idev);int ret;idev->buffer = iio_sw_rb_allocate(idev);if (!idev->buffer)ret = -ENOMEM;idev->buffer->access = &ring_sw_access_funcs;idev->buffer->setup_ops = &tiadc_swring_setup_ops;INIT_WORK(&adc_dev->poll_work, &tiadc_poll_handler);idev->modes |= INDIO_BUFFER_HARDWARE;return 0; }static int tiadc_channel_init(struct iio_dev *idev, struct adc_device *adc_dev) {struct iio_chan_spec *chan_array;int i, channels;idev->num_channels = adc_dev->channels;chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),GFP_KERNEL);if (chan_array == NULL)return -ENOMEM;channels = TOTAL_CHANNELS - adc_dev->channels;for (i = 0; i < (idev->num_channels); i++) {struct iio_chan_spec *chan = chan_array + i;chan->type = IIO_VOLTAGE;chan->indexed = 1;chan->channel = channels;chan->scan_index = i;chan->scan_type.sign = 'u';chan->scan_type.realbits = 12;chan->scan_type.storagebits = 32;chan->scan_type.shift = 0;channels++;}idev->channels = chan_array;return idev->num_channels; }static void tiadc_channel_remove(struct iio_dev *idev) {kfree(idev->channels); }static int tiadc_read_raw(struct iio_dev *idev,struct iio_chan_spec const *chan,int *val, int *val2, long mask) {struct adc_device *adc_dev = iio_priv(idev);int i, map_val, tmp;unsigned int fifo1count, readx1, stepid;unsigned long timeout = jiffies + usecs_to_jiffies(IDLE_TIMEOUT * adc_dev->channels);if (adc_dev->is_continuous_mode) {pr_info("One shot mode not enabled\n");return -EINVAL;} else {if(adc_dev->channels == 4)tmp= (1 << (chan->channel + TOTAL_CHANNELS + 1)) | TSCADC_STPENB_STEPENB_TC;elsetmp= (1 << (chan->channel + TOTAL_CHANNELS + 1));adc_writel(adc_dev, TSCADC_REG_SE, tmp);/* Wait for ADC sequencer to complete sampling */while (adc_readl(adc_dev, TSCADC_REG_ADCFSM) &TSCADC_SEQ_STATUS) {if (time_after(jiffies, timeout))return -EAGAIN;}map_val = chan->channel + TOTAL_CHANNELS;*val = -1;timeout = jiffies + usecs_to_jiffies(IDLE_TIMEOUT * adc_dev->channels);while(1){fifo1count = adc_readl(adc_dev, TSCADC_REG_FIFO1CNT);if(!fifo1count){if (time_after(jiffies, timeout)){printk("wait fifo timeout\n");return -EAGAIN;} elsecontinue;}for (i = 0; i < fifo1count; i++) {readx1 = adc_readl(adc_dev, TSCADC_REG_FIFO1);stepid = readx1 & TSCADC_FIFOREAD_CHNLID_MASK;stepid = stepid >> 0x10;if (stepid == map_val) {readx1 = readx1 & TSCADC_FIFOREAD_DATA_MASK;*val = readx1;}}if(*val != -1){break;}}return IIO_VAL_INT;} }static const struct iio_info tiadc_info = {.read_raw = &tiadc_read_raw,.attrs = &tiadc_attribute_group, };static int __devinit tiadc_probe(struct platform_device *pdev) {struct iio_dev*idev;struct adc_device *adc_dev = NULL;struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;struct mfd_tscadc_board *pdata;interr;pdata = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;if (!pdata || !pdata->adc_init){dev_err(tscadc_dev->dev, "Could not find platform data\n");return -EINVAL;}idev = iio_allocate_device(sizeof(struct adc_device));if (idev == NULL) {dev_err(&pdev->dev, "failed to allocate iio device.\n");err = -ENOMEM;goto err_ret;}adc_dev = iio_priv(idev);tscadc_dev->adc = adc_dev;adc_dev->mfd_tscadc = tscadc_dev;adc_dev->idev = idev;adc_dev->channels = pdata->adc_init->adc_channels;adc_dev->irq = tscadc_dev->irq;idev->dev.parent = &pdev->dev;idev->name = dev_name(&pdev->dev);idev->modes = INDIO_DIRECT_MODE;idev->info = &tiadc_info;/* by default driver comes up with oneshot mode */adc_step_config(adc_dev, adc_dev->is_continuous_mode);/* program FIFO threshold to value minus 1 */adc_writel(adc_dev, TSCADC_REG_FIFO1THR, FIFO1_THRESHOLD);err = tiadc_channel_init(idev, adc_dev);if (err < 0)goto err_free_device;init_waitqueue_head(&adc_dev->wq_data_avail);err = request_irq(adc_dev->irq, tiadc_irq, IRQF_SHARED,idev->name, idev);if (err)goto err_cleanup_channels;err = tiadc_config_sw_ring(idev);if (err)goto err_free_irq;err = iio_buffer_register(idev,idev->channels, idev->num_channels);if (err < 0)goto err_free_sw_rb;err = iio_device_register(idev);if (err)goto err_unregister;dev_info(&pdev->dev, "attached adc driver\n");platform_set_drvdata(pdev, idev);return 0;err_unregister:iio_buffer_unregister(idev); err_free_sw_rb:iio_sw_rb_free(idev->buffer); err_free_irq:free_irq(adc_dev->irq, idev); err_cleanup_channels:tiadc_channel_remove(idev); err_free_device:iio_free_device(idev); err_ret:return err; }static int __devexit tiadc_remove(struct platform_device *pdev) {struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;struct adc_device *adc_dev = tscadc_dev->adc;struct iio_dev*idev = adc_dev->idev;free_irq(adc_dev->irq, idev);iio_device_unregister(idev);iio_buffer_unregister(idev);iio_sw_rb_free(idev->buffer);tiadc_channel_remove(idev);tscadc_dev->adc = NULL;iio_free_device(idev);platform_set_drvdata(pdev, NULL);return 0; }static int adc_suspend(struct platform_device *pdev, pm_message_t state) {struct ti_tscadc_dev*tscadc_dev = pdev->dev.platform_data;struct adc_device *adc_dev = tscadc_dev->adc;unsigned int idle;if (!device_may_wakeup(tscadc_dev->dev)) {idle = adc_readl(adc_dev, TSCADC_REG_CTRL);idle &= ~(TSCADC_CNTRLREG_TSCSSENB);adc_writel(adc_dev, TSCADC_REG_CTRL, (idle |TSCADC_CNTRLREG_POWERDOWN));}return 0; }static int adc_resume(struct platform_device *pdev) {struct ti_tscadc_dev*tscadc_dev = pdev->dev.platform_data;struct adc_device *adc_dev = tscadc_dev->adc;unsigned int restore;restore = adc_readl(adc_dev, TSCADC_REG_CTRL);restore &= ~(TSCADC_CNTRLREG_TSCSSENB);adc_writel(adc_dev, TSCADC_REG_CTRL, restore);adc_writel(adc_dev, TSCADC_REG_FIFO1THR, FIFO1_THRESHOLD);adc_step_config(adc_dev, adc_dev->is_continuous_mode);/* Make sure ADC is powered up */restore &= ~(TSCADC_CNTRLREG_POWERDOWN);restore |= TSCADC_CNTRLREG_TSCSSENB;adc_writel(adc_dev, TSCADC_REG_CTRL, restore);return 0; }static struct platform_driver tiadc_driver = {.driver = {.name= "tiadc",.owner = THIS_MODULE,},.probe= tiadc_probe,.remove= __devexit_p(tiadc_remove),.suspend = adc_suspend,.resume = adc_resume, };module_platform_driver(tiadc_driver);MODULE_DESCRIPTION("TI ADC controller driver"); MODULE_AUTHOR("Rachna Patil <rachna@ti.com>"); MODULE_LICENSE("GPL");
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Nancy Wang：
我是指以下链接中 Device Tree 部分的配置。
https://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components/Kernel/Kernel_Drivers/ADC.html#adc
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user6044729：
我的内核是板级文件配置，没有使用设备树，配置如下
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Nancy Wang：
好的，我会咨询相关工程师再给您回复。
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Nancy Wang：
Linux 内核 3.2 太旧，我们无法支持。该版本的ADC 驱动程序和 Linux 5.4 之间有很多变化（肯定的是在驱动程序的触摸屏部分有变化，不确定 tscadc 驱动程序的其他部分）。如果您可以在 Linux Processor SDK 6.3 或 Linux Processor SDK 7.3 上复现问题，我们将能够提供更好的支持。
另外请问该现象是在一块板子上出现的还是多块板子？
