- 根目录:
- drivers
- iio
- adc
- vf610_adc.c
/*
* Freescale Vybrid vf610 ADC driver
*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/regulator/consumer.h>
#include <linux/of_platform.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/driver.h>
/* This will be the driver name the kernel reports */
#define DRIVER_NAME "vf610-adc"
/* Vybrid/IMX ADC registers */
#define VF610_REG_ADC_HC0 0x00
#define VF610_REG_ADC_HC1 0x04
#define VF610_REG_ADC_HS 0x08
#define VF610_REG_ADC_R0 0x0c
#define VF610_REG_ADC_R1 0x10
#define VF610_REG_ADC_CFG 0x14
#define VF610_REG_ADC_GC 0x18
#define VF610_REG_ADC_GS 0x1c
#define VF610_REG_ADC_CV 0x20
#define VF610_REG_ADC_OFS 0x24
#define VF610_REG_ADC_CAL 0x28
#define VF610_REG_ADC_PCTL 0x30
/* Configuration register field define */
#define VF610_ADC_MODE_BIT8 0x00
#define VF610_ADC_MODE_BIT10 0x04
#define VF610_ADC_MODE_BIT12 0x08
#define VF610_ADC_MODE_MASK 0x0c
#define VF610_ADC_BUSCLK2_SEL 0x01
#define VF610_ADC_ALTCLK_SEL 0x02
#define VF610_ADC_ADACK_SEL 0x03
#define VF610_ADC_ADCCLK_MASK 0x03
#define VF610_ADC_CLK_DIV2 0x20
#define VF610_ADC_CLK_DIV4 0x40
#define VF610_ADC_CLK_DIV8 0x60
#define VF610_ADC_CLK_MASK 0x60
#define VF610_ADC_ADLSMP_LONG 0x10
#define VF610_ADC_ADSTS_MASK 0x300
#define VF610_ADC_ADLPC_EN 0x80
#define VF610_ADC_ADHSC_EN 0x400
#define VF610_ADC_REFSEL_VALT 0x100
#define VF610_ADC_REFSEL_VBG 0x1000
#define VF610_ADC_ADTRG_HARD 0x2000
#define VF610_ADC_AVGS_8 0x4000
#define VF610_ADC_AVGS_16 0x8000
#define VF610_ADC_AVGS_32 0xC000
#define VF610_ADC_AVGS_MASK 0xC000
#define VF610_ADC_OVWREN 0x10000
/* General control register field define */
#define VF610_ADC_ADACKEN 0x1
#define VF610_ADC_DMAEN 0x2
#define VF610_ADC_ACREN 0x4
#define VF610_ADC_ACFGT 0x8
#define VF610_ADC_ACFE 0x10
#define VF610_ADC_AVGEN 0x20
#define VF610_ADC_ADCON 0x40
#define VF610_ADC_CAL 0x80
/* Other field define */
#define VF610_ADC_ADCHC(x) ((x) & 0x1F)
#define VF610_ADC_AIEN (0x1 << 7)
#define VF610_ADC_CONV_DISABLE 0x1F
#define VF610_ADC_HS_COCO0 0x1
#define VF610_ADC_CALF 0x2
#define VF610_ADC_TIMEOUT msecs_to_jiffies(100)
enum clk_sel {
VF610_ADCIOC_BUSCLK_SET,
VF610_ADCIOC_ALTCLK_SET,
VF610_ADCIOC_ADACK_SET,
};
enum vol_ref {
VF610_ADCIOC_VR_VREF_SET,
VF610_ADCIOC_VR_VALT_SET,
VF610_ADCIOC_VR_VBG_SET,
};
enum average_sel {
VF610_ADC_SAMPLE_1,
VF610_ADC_SAMPLE_4,
VF610_ADC_SAMPLE_8,
VF610_ADC_SAMPLE_16,
VF610_ADC_SAMPLE_32,
};
struct vf610_adc_feature {
enum clk_sel clk_sel;
enum vol_ref vol_ref;
int clk_div;
int sample_rate;
int res_mode;
bool lpm;
bool calibration;
bool ovwren;
};
struct vf610_adc {
struct device *dev;
void __iomem *regs;
struct clk *clk;
u32 vref_uv;
u32 value;
struct regulator *vref;
struct vf610_adc_feature adc_feature;
u32 sample_freq_avail[5];
struct completion completion;
};
static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 };
#define VF610_ADC_CHAN(_idx, _chan_type) { \
.type = (_chan_type), \
.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), \
}
#define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) { \
.type = (_chan_type), \
.channel = (_idx), \
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
}
static const struct iio_chan_spec vf610_adc_iio_channels[] = {
VF610_ADC_CHAN(0, IIO_VOLTAGE),
VF610_ADC_CHAN(1, IIO_VOLTAGE),
VF610_ADC_CHAN(2, IIO_VOLTAGE),
VF610_ADC_CHAN(3, IIO_VOLTAGE),
VF610_ADC_CHAN(4, IIO_VOLTAGE),
VF610_ADC_CHAN(5, IIO_VOLTAGE),
VF610_ADC_CHAN(6, IIO_VOLTAGE),
VF610_ADC_CHAN(7, IIO_VOLTAGE),
VF610_ADC_CHAN(8, IIO_VOLTAGE),
VF610_ADC_CHAN(9, IIO_VOLTAGE),
VF610_ADC_CHAN(10, IIO_VOLTAGE),
VF610_ADC_CHAN(11, IIO_VOLTAGE),
VF610_ADC_CHAN(12, IIO_VOLTAGE),
VF610_ADC_CHAN(13, IIO_VOLTAGE),
VF610_ADC_CHAN(14, IIO_VOLTAGE),
VF610_ADC_CHAN(15, IIO_VOLTAGE),
VF610_ADC_TEMPERATURE_CHAN(26, IIO_TEMP),
/* sentinel */
};
static inline void vf610_adc_calculate_rates(struct vf610_adc *info)
{
unsigned long adck_rate, ipg_rate = clk_get_rate(info->clk);
int i;
/*
* Calculate ADC sample frequencies
* Sample time unit is ADCK cycles. ADCK clk source is ipg clock,
* which is the same as bus clock.
*
* ADC conversion time = SFCAdder + AverageNum x (BCT + LSTAdder)
* SFCAdder: fixed to 6 ADCK cycles
* AverageNum: 1, 4, 8, 16, 32 samples for hardware average.
* BCT (Base Conversion Time): fixed to 25 ADCK cycles for 12 bit mode
* LSTAdder(Long Sample Time): fixed to 3 ADCK cycles
*/
adck_rate = ipg_rate / info->adc_feature.clk_div;
for (i = 0; i < ARRAY_SIZE(vf610_hw_avgs); i++)
info->sample_freq_avail[i] =
adck_rate / (6 + vf610_hw_avgs[i] * (25 + 3));
}
static inline void vf610_adc_cfg_init(struct vf610_adc *info)
{
struct vf610_adc_feature *adc_feature = &info->adc_feature;
/* set default Configuration for ADC controller */
adc_feature->clk_sel = VF610_ADCIOC_BUSCLK_SET;
adc_feature->vol_ref = VF610_ADCIOC_VR_VREF_SET;
adc_feature->calibration = true;
adc_feature->ovwren = true;
adc_feature->res_mode = 12;
adc_feature->sample_rate = 1;
adc_feature->lpm = true;
/* Use a save ADCK which is below 20MHz on all devices */
adc_feature->clk_div = 8;
vf610_adc_calculate_rates(info);
}
static void vf610_adc_cfg_post_set(struct vf610_adc *info)
{
struct vf610_adc_feature *adc_feature = &info->adc_feature;
int cfg_data = 0;
int gc_data = 0;
switch (adc_feature->clk_sel) {
case VF610_ADCIOC_ALTCLK_SET:
cfg_data |= VF610_ADC_ALTCLK_SEL;
break;
case VF610_ADCIOC_ADACK_SET:
cfg_data |= VF610_ADC_ADACK_SEL;
break;
default:
break;
}
/* low power set for calibration */
cfg_data |= VF610_ADC_ADLPC_EN;
/* enable high speed for calibration */
cfg_data |= VF610_ADC_ADHSC_EN;
/* voltage reference */
switch (adc_feature->vol_ref) {
case VF610_ADCIOC_VR_VREF_SET:
break;
case VF610_ADCIOC_VR_VALT_SET:
cfg_data |= VF610_ADC_REFSEL_VALT;
break;
case VF610_ADCIOC_VR_VBG_SET:
cfg_data |= VF610_ADC_REFSEL_VBG;
break;
default:
dev_err(info->dev, "error voltage reference\n");
}
/* data overwrite enable */
if (adc_feature->ovwren)
cfg_data |= VF610_ADC_OVWREN;
writel(cfg_data, info->regs + VF610_REG_ADC_CFG);
writel(gc_data, info->regs + VF610_REG_ADC_GC);
}
static void vf610_adc_calibration(struct vf610_adc *info)
{
int adc_gc, hc_cfg;
if (!info->adc_feature.calibration)
return;
/* enable calibration interrupt */
hc_cfg = VF610_ADC_AIEN | VF610_ADC_CONV_DISABLE;
writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
adc_gc = readl(info->regs + VF610_REG_ADC_GC);
writel(adc_gc | VF610_ADC_CAL, info->regs + VF610_REG_ADC_GC);
if (!wait_for_completion_timeout(&info->completion, VF610_ADC_TIMEOUT))
dev_err(info->dev, "Timeout for adc calibration\n");
adc_gc = readl(info->regs + VF610_REG_ADC_GS);
if (adc_gc & VF610_ADC_CALF)
dev_err(info->dev, "ADC calibration failed\n");
info->adc_feature.calibration = false;
}
static void vf610_adc_cfg_set(struct vf610_adc *info)
{
struct vf610_adc_feature *adc_feature = &(info->adc_feature);
int cfg_data;
cfg_data = readl(info->regs + VF610_REG_ADC_CFG);
cfg_data &= ~VF610_ADC_ADLPC_EN;
if (adc_feature->lpm)
cfg_data |= VF610_ADC_ADLPC_EN;
cfg_data &= ~VF610_ADC_ADHSC_EN;
writel(cfg_data, info->regs + VF610_REG_ADC_CFG);
}
static void vf610_adc_sample_set(struct vf610_adc *info)
{
struct vf610_adc_feature *adc_feature = &(info->adc_feature);
int cfg_data, gc_data;
cfg_data = readl(info->regs + VF610_REG_ADC_CFG);
gc_data = readl(info->regs + VF610_REG_ADC_GC);
/* resolution mode */
cfg_data &= ~VF610_ADC_MODE_MASK;
switch (adc_feature->res_mode) {
case 8:
cfg_data |= VF610_ADC_MODE_BIT8;
break;
case 10:
cfg_data |= VF610_ADC_MODE_BIT10;
break;
case 12:
cfg_data |= VF610_ADC_MODE_BIT12;
break;
default:
dev_err(info->dev, "error resolution mode\n");
break;
}
/* clock select and clock divider */
cfg_data &= ~(VF610_ADC_CLK_MASK | VF610_ADC_ADCCLK_MASK);
switch (adc_feature->clk_div) {
case 1:
break;
case 2:
cfg_data |= VF610_ADC_CLK_DIV2;
break;
case 4:
cfg_data |= VF610_ADC_CLK_DIV4;
break;
case 8:
cfg_data |= VF610_ADC_CLK_DIV8;
break;
case 16:
switch (adc_feature->clk_sel) {
case VF610_ADCIOC_BUSCLK_SET:
cfg_data |= VF610_ADC_BUSCLK2_SEL | VF610_ADC_CLK_DIV8;
break;
default:
dev_err(info->dev, "error clk divider\n");
break;
}
break;
}
/* Use the short sample mode */
cfg_data &= ~(VF610_ADC_ADLSMP_LONG | VF610_ADC_ADSTS_MASK);
/* update hardware average selection */
cfg_data &= ~VF610_ADC_AVGS_MASK;
gc_data &= ~VF610_ADC_AVGEN;
switch (adc_feature->sample_rate) {
case VF610_ADC_SAMPLE_1:
break;
case VF610_ADC_SAMPLE_4:
gc_data |= VF610_ADC_AVGEN;
break;
case VF610_ADC_SAMPLE_8:
gc_data |= VF610_ADC_AVGEN;
cfg_data |= VF610_ADC_AVGS_8;
break;
case VF610_ADC_SAMPLE_16:
gc_data |= VF610_ADC_AVGEN;
cfg_data |= VF610_ADC_AVGS_16;
break;
case VF610_ADC_SAMPLE_32:
gc_data |= VF610_ADC_AVGEN;
cfg_data |= VF610_ADC_AVGS_32;
break;
default:
dev_err(info->dev,
"error hardware sample average select\n");
}
writel(cfg_data, info->regs + VF610_REG_ADC_CFG);
writel(gc_data, info->regs + VF610_REG_ADC_GC);
}
static void vf610_adc_hw_init(struct vf610_adc *info)
{
/* CFG: Feature set */
vf610_adc_cfg_post_set(info);
vf610_adc_sample_set(info);
/* adc calibration */
vf610_adc_calibration(info);
/* CFG: power and speed set */
vf610_adc_cfg_set(info);
}
static int vf610_adc_read_data(struct vf610_adc *info)
{
int result;
result = readl(info->regs + VF610_REG_ADC_R0);
switch (info->adc_feature.res_mode) {
case 8:
result &= 0xFF;
break;
case 10:
result &= 0x3FF;
break;
case 12:
result &= 0xFFF;
break;
default:
break;
}
return result;
}
static irqreturn_t vf610_adc_isr(int irq, void *dev_id)
{
struct vf610_adc *info = (struct vf610_adc *)dev_id;
int coco;
coco = readl(info->regs + VF610_REG_ADC_HS);
if (coco & VF610_ADC_HS_COCO0) {
info->value = vf610_adc_read_data(info);
complete(&info->completion);
}
return IRQ_HANDLED;
}
static ssize_t vf610_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct vf610_adc *info = iio_priv(dev_to_iio_dev(dev));
size_t len = 0;
int i;
for (i = 0; i < ARRAY_SIZE(info->sample_freq_avail); i++)
len += scnprintf(buf + len, PAGE_SIZE - len,
"%u ", info->sample_freq_avail[i]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(vf610_show_samp_freq_avail);
static struct attribute *vf610_attributes[] = {
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
NULL
};
static const struct attribute_group vf610_attribute_group = {
.attrs = vf610_attributes,
};
static int vf610_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct vf610_adc *info = iio_priv(indio_dev);
unsigned int hc_cfg;
long ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
case IIO_CHAN_INFO_PROCESSED:
mutex_lock(&indio_dev->mlock);
reinit_completion(&info->completion);
hc_cfg = VF610_ADC_ADCHC(chan->channel);
hc_cfg |= VF610_ADC_AIEN;
writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
ret = wait_for_completion_interruptible_timeout
(&info->completion, VF610_ADC_TIMEOUT);
if (ret == 0) {
mutex_unlock(&indio_dev->mlock);
return -ETIMEDOUT;
}
if (ret < 0) {
mutex_unlock(&indio_dev->mlock);
return ret;
}
switch (chan->type) {
case IIO_VOLTAGE:
*val = info->value;
break;
case IIO_TEMP:
/*
* Calculate in degree Celsius times 1000
* Using sensor slope of 1.84 mV/°C and
* V at 25°C of 696 mV
*/
*val = 25000 - ((int)info->value - 864) * 1000000 / 1840;
break;
default:
mutex_unlock(&indio_dev->mlock);
return -EINVAL;
}
mutex_unlock(&indio_dev->mlock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = info->vref_uv / 1000;
*val2 = info->adc_feature.res_mode;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = info->sample_freq_avail[info->adc_feature.sample_rate];
*val2 = 0;
return IIO_VAL_INT;
default:
break;
}
return -EINVAL;
}
static int vf610_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct vf610_adc *info = iio_priv(indio_dev);
int i;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
for (i = 0;
i < ARRAY_SIZE(info->sample_freq_avail);
i++)
if (val == info->sample_freq_avail[i]) {
info->adc_feature.sample_rate = i;
vf610_adc_sample_set(info);
return 0;
}
break;
default:
break;
}
return -EINVAL;
}
static int vf610_adc_reg_access(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
{
struct vf610_adc *info = iio_priv(indio_dev);
if ((readval == NULL) ||
(!(reg % 4) || (reg > VF610_REG_ADC_PCTL)))
return -EINVAL;
*readval = readl(info->regs + reg);
return 0;
}
static const struct iio_info vf610_adc_iio_info = {
.driver_module = THIS_MODULE,
.read_raw = &vf610_read_raw,
.write_raw = &vf610_write_raw,
.debugfs_reg_access = &vf610_adc_reg_access,
.attrs = &vf610_attribute_group,
};
static const struct of_device_id vf610_adc_match[] = {
{ .compatible = "fsl,vf610-adc", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, vf610_adc_match);
static int vf610_adc_probe(struct platform_device *pdev)
{
struct vf610_adc *info;
struct iio_dev *indio_dev;
struct resource *mem;
int irq;
int ret;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct vf610_adc));
if (!indio_dev) {
dev_err(&pdev->dev, "Failed allocating iio device\n");
return -ENOMEM;
}
info = iio_priv(indio_dev);
info->dev = &pdev->dev;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
info->regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(info->regs))
return PTR_ERR(info->regs);
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return irq;
}
ret = devm_request_irq(info->dev, irq,
vf610_adc_isr, 0,
dev_name(&pdev->dev), info);
if (ret < 0) {
dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);
return ret;
}
info->clk = devm_clk_get(&pdev->dev, "adc");
if (IS_ERR(info->clk)) {
dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
PTR_ERR(info->clk));
return PTR_ERR(info->clk);
}
info->vref = devm_regulator_get(&pdev->dev, "vref");
if (IS_ERR(info->vref))
return PTR_ERR(info->vref);
ret = regulator_enable(info->vref);
if (ret)
return ret;
info->vref_uv = regulator_get_voltage(info->vref);
platform_set_drvdata(pdev, indio_dev);
init_completion(&info->completion);
indio_dev->name = dev_name(&pdev->dev);
indio_dev->dev.parent = &pdev->dev;
indio_dev->dev.of_node = pdev->dev.of_node;
indio_dev->info = &vf610_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = vf610_adc_iio_channels;
indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
ret = clk_prepare_enable(info->clk);
if (ret) {
dev_err(&pdev->dev,
"Could not prepare or enable the clock.\n");
goto error_adc_clk_enable;
}
vf610_adc_cfg_init(info);
vf610_adc_hw_init(info);
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&pdev->dev, "Couldn't register the device.\n");
goto error_iio_device_register;
}
return 0;
error_iio_device_register:
clk_disable_unprepare(info->clk);
error_adc_clk_enable:
regulator_disable(info->vref);
return ret;
}
static int vf610_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct vf610_adc *info = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
regulator_disable(info->vref);
clk_disable_unprepare(info->clk);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int vf610_adc_suspend(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct vf610_adc *info = iio_priv(indio_dev);
int hc_cfg;
/* ADC controller enters to stop mode */
hc_cfg = readl(info->regs + VF610_REG_ADC_HC0);
hc_cfg |= VF610_ADC_CONV_DISABLE;
writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
clk_disable_unprepare(info->clk);
regulator_disable(info->vref);
return 0;
}
static int vf610_adc_resume(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct vf610_adc *info = iio_priv(indio_dev);
int ret;
ret = regulator_enable(info->vref);
if (ret)
return ret;
ret = clk_prepare_enable(info->clk);
if (ret)
goto disable_reg;
vf610_adc_hw_init(info);
return 0;
disable_reg:
regulator_disable(info->vref);
return ret;
}
#endif
static SIMPLE_DEV_PM_OPS(vf610_adc_pm_ops, vf610_adc_suspend, vf610_adc_resume);
static struct platform_driver vf610_adc_driver = {
.probe = vf610_adc_probe,
.remove = vf610_adc_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = vf610_adc_match,
.pm = &vf610_adc_pm_ops,
},
};
module_platform_driver(vf610_adc_driver);
MODULE_AUTHOR("Fugang Duan <B38611@freescale.com>");
MODULE_DESCRIPTION("Freescale VF610 ADC driver");
MODULE_LICENSE("GPL v2");