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/*
* Freescale i.MX7D ADC driver
*
* Copyright (C) 2015 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.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/iio/sysfs.h>
/* ADC register */
#define IMX7D_REG_ADC_CH_A_CFG1 0x00
#define IMX7D_REG_ADC_CH_A_CFG2 0x10
#define IMX7D_REG_ADC_CH_B_CFG1 0x20
#define IMX7D_REG_ADC_CH_B_CFG2 0x30
#define IMX7D_REG_ADC_CH_C_CFG1 0x40
#define IMX7D_REG_ADC_CH_C_CFG2 0x50
#define IMX7D_REG_ADC_CH_D_CFG1 0x60
#define IMX7D_REG_ADC_CH_D_CFG2 0x70
#define IMX7D_REG_ADC_CH_SW_CFG 0x80
#define IMX7D_REG_ADC_TIMER_UNIT 0x90
#define IMX7D_REG_ADC_DMA_FIFO 0xa0
#define IMX7D_REG_ADC_FIFO_STATUS 0xb0
#define IMX7D_REG_ADC_INT_SIG_EN 0xc0
#define IMX7D_REG_ADC_INT_EN 0xd0
#define IMX7D_REG_ADC_INT_STATUS 0xe0
#define IMX7D_REG_ADC_CHA_B_CNV_RSLT 0xf0
#define IMX7D_REG_ADC_CHC_D_CNV_RSLT 0x100
#define IMX7D_REG_ADC_CH_SW_CNV_RSLT 0x110
#define IMX7D_REG_ADC_DMA_FIFO_DAT 0x120
#define IMX7D_REG_ADC_ADC_CFG 0x130
#define IMX7D_REG_ADC_CHANNEL_CFG2_BASE 0x10
#define IMX7D_EACH_CHANNEL_REG_OFFSET 0x20
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN (0x1 << 31)
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE BIT(30)
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN BIT(29)
#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x) ((x) << 24)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4 (0x0 << 12)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8 (0x1 << 12)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16 (0x2 << 12)
#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32 (0x3 << 12)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4 (0x0 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8 (0x1 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16 (0x2 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32 (0x3 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64 (0x4 << 29)
#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128 (0x5 << 29)
#define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN BIT(31)
#define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN BIT(1)
#define IMX7D_REG_ADC_ADC_CFG_ADC_EN BIT(0)
#define IMX7D_REG_ADC_INT_CHA_COV_INT_EN BIT(8)
#define IMX7D_REG_ADC_INT_CHB_COV_INT_EN BIT(9)
#define IMX7D_REG_ADC_INT_CHC_COV_INT_EN BIT(10)
#define IMX7D_REG_ADC_INT_CHD_COV_INT_EN BIT(11)
#define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \
(IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
#define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS 0xf00
#define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT 0xf0000
#define IMX7D_ADC_TIMEOUT msecs_to_jiffies(100)
enum imx7d_adc_clk_pre_div {
IMX7D_ADC_ANALOG_CLK_PRE_DIV_4,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_8,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_16,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_32,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_64,
IMX7D_ADC_ANALOG_CLK_PRE_DIV_128,
};
enum imx7d_adc_average_num {
IMX7D_ADC_AVERAGE_NUM_4,
IMX7D_ADC_AVERAGE_NUM_8,
IMX7D_ADC_AVERAGE_NUM_16,
IMX7D_ADC_AVERAGE_NUM_32,
};
struct imx7d_adc_feature {
enum imx7d_adc_clk_pre_div clk_pre_div;
enum imx7d_adc_average_num avg_num;
u32 core_time_unit; /* impact the sample rate */
bool average_en;
};
struct imx7d_adc {
struct device *dev;
void __iomem *regs;
struct clk *clk;
u32 vref_uv;
u32 value;
u32 channel;
u32 pre_div_num;
struct regulator *vref;
struct imx7d_adc_feature adc_feature;
struct completion completion;
};
struct imx7d_adc_analogue_core_clk {
u32 pre_div;
u32 reg_config;
};
#define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) { \
.pre_div = (_pre_div), \
.reg_config = (_reg_conf), \
}
static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk[] = {
IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64),
IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128),
};
#define IMX7D_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 imx7d_adc_iio_channels[] = {
IMX7D_ADC_CHAN(0),
IMX7D_ADC_CHAN(1),
IMX7D_ADC_CHAN(2),
IMX7D_ADC_CHAN(3),
IMX7D_ADC_CHAN(4),
IMX7D_ADC_CHAN(5),
IMX7D_ADC_CHAN(6),
IMX7D_ADC_CHAN(7),
IMX7D_ADC_CHAN(8),
IMX7D_ADC_CHAN(9),
IMX7D_ADC_CHAN(10),
IMX7D_ADC_CHAN(11),
IMX7D_ADC_CHAN(12),
IMX7D_ADC_CHAN(13),
IMX7D_ADC_CHAN(14),
IMX7D_ADC_CHAN(15),
};
static const u32 imx7d_adc_average_num[] = {
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4,
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8,
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16,
IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32,
};
static void imx7d_adc_feature_config(struct imx7d_adc *info)
{
info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4;
info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32;
info->adc_feature.core_time_unit = 1;
info->adc_feature.average_en = true;
}
static void imx7d_adc_sample_rate_set(struct imx7d_adc *info)
{
struct imx7d_adc_feature *adc_feature = &info->adc_feature;
struct imx7d_adc_analogue_core_clk adc_analogure_clk;
u32 i;
u32 tmp_cfg1;
u32 sample_rate = 0;
/*
* Before sample set, disable channel A,B,C,D. Here we
* clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
*/
for (i = 0; i < 4; i++) {
tmp_cfg1 =
readl(info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
tmp_cfg1 &= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN;
writel(tmp_cfg1,
info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
}
adc_analogure_clk = imx7d_adc_analogue_clk[adc_feature->clk_pre_div];
sample_rate |= adc_analogure_clk.reg_config;
info->pre_div_num = adc_analogure_clk.pre_div;
sample_rate |= adc_feature->core_time_unit;
writel(sample_rate, info->regs + IMX7D_REG_ADC_TIMER_UNIT);
}
static void imx7d_adc_hw_init(struct imx7d_adc *info)
{
u32 cfg;
/* power up and enable adc analogue core */
cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
cfg &= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN);
cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_EN;
writel(cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
/* enable channel A,B,C,D interrupt */
writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
info->regs + IMX7D_REG_ADC_INT_SIG_EN);
writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
info->regs + IMX7D_REG_ADC_INT_EN);
imx7d_adc_sample_rate_set(info);
}
static void imx7d_adc_channel_set(struct imx7d_adc *info)
{
u32 cfg1 = 0;
u32 cfg2;
u32 channel;
channel = info->channel;
/* the channel choose single conversion, and enable average mode */
cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN |
IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE);
if (info->adc_feature.average_en)
cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN;
/*
* physical channel 0 chose logical channel A
* physical channel 1 chose logical channel B
* physical channel 2 chose logical channel C
* physical channel 3 chose logical channel D
*/
cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel);
/*
* read register REG_ADC_CH_A\B\C\D_CFG2, according to the
* channel chosen
*/
cfg2 = readl(info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
cfg2 |= imx7d_adc_average_num[info->adc_feature.avg_num];
/*
* write the register REG_ADC_CH_A\B\C\D_CFG2, according to
* the channel chosen
*/
writel(cfg2, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
writel(cfg1, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel);
}
static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info)
{
/* input clock is always 24MHz */
u32 input_clk = 24000000;
u32 analogue_core_clk;
u32 core_time_unit = info->adc_feature.core_time_unit;
u32 tmp;
analogue_core_clk = input_clk / info->pre_div_num;
tmp = (core_time_unit + 1) * 6;
return analogue_core_clk / tmp;
}
static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
struct imx7d_adc *info = iio_priv(indio_dev);
u32 channel;
long ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&indio_dev->mlock);
reinit_completion(&info->completion);
channel = chan->channel & 0x03;
info->channel = channel;
imx7
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