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u-boot/drivers/adc/meson-saradc.c
Marek Szyprowski 97ab802aa3 adc: meson-saradc: add support for getting reference voltage value 
Add support for getting the 'vref-supply' regulator and register it as
ADC's reference voltage regulator, so clients can translate sampled ADC
values to the voltage.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
2021-02-18 11:37:26 +01:00

751 lines
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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
* Copyright (C) 2018 BayLibre, SAS
* Author: Neil Armstrong <narmstrong@baylibre.com>
*
* Amlogic Meson Successive Approximation Register (SAR) A/D Converter
*/
#include <common.h>
#include <adc.h>
#include <clk.h>
#include <dm.h>
#include <regmap.h>
#include <errno.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/math64.h>
#include <linux/bitfield.h>
#include <power/regulator.h>
#define MESON_SAR_ADC_REG0 0x00
#define MESON_SAR_ADC_REG0_PANEL_DETECT BIT(31)
#define MESON_SAR_ADC_REG0_BUSY_MASK GENMASK(30, 28)
#define MESON_SAR_ADC_REG0_DELTA_BUSY BIT(30)
#define MESON_SAR_ADC_REG0_AVG_BUSY BIT(29)
#define MESON_SAR_ADC_REG0_SAMPLE_BUSY BIT(28)
#define MESON_SAR_ADC_REG0_FIFO_FULL BIT(27)
#define MESON_SAR_ADC_REG0_FIFO_EMPTY BIT(26)
#define MESON_SAR_ADC_REG0_FIFO_COUNT_MASK GENMASK(25, 21)
#define MESON_SAR_ADC_REG0_ADC_BIAS_CTRL_MASK GENMASK(20, 19)
#define MESON_SAR_ADC_REG0_CURR_CHAN_ID_MASK GENMASK(18, 16)
#define MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL BIT(15)
#define MESON_SAR_ADC_REG0_SAMPLING_STOP BIT(14)
#define MESON_SAR_ADC_REG0_CHAN_DELTA_EN_MASK GENMASK(13, 12)
#define MESON_SAR_ADC_REG0_DETECT_IRQ_POL BIT(10)
#define MESON_SAR_ADC_REG0_DETECT_IRQ_EN BIT(9)
#define MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK GENMASK(8, 4)
#define MESON_SAR_ADC_REG0_FIFO_IRQ_EN BIT(3)
#define MESON_SAR_ADC_REG0_SAMPLING_START BIT(2)
#define MESON_SAR_ADC_REG0_CONTINUOUS_EN BIT(1)
#define MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE BIT(0)
#define MESON_SAR_ADC_CHAN_LIST 0x04
#define MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK GENMASK(26, 24)
#define MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(_chan) \
(GENMASK(2, 0) << ((_chan) * 3))
#define MESON_SAR_ADC_AVG_CNTL 0x08
#define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(_chan) \
(16 + ((_chan) * 2))
#define MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(_chan) \
(GENMASK(17, 16) << ((_chan) * 2))
#define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(_chan) \
(0 + ((_chan) * 2))
#define MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(_chan) \
(GENMASK(1, 0) << ((_chan) * 2))
#define MESON_SAR_ADC_REG3 0x0c
#define MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY BIT(31)
#define MESON_SAR_ADC_REG3_CLK_EN BIT(30)
#define MESON_SAR_ADC_REG3_BL30_INITIALIZED BIT(28)
#define MESON_SAR_ADC_REG3_CTRL_CONT_RING_COUNTER_EN BIT(27)
#define MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE BIT(26)
#define MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK GENMASK(25, 23)
#define MESON_SAR_ADC_REG3_DETECT_EN BIT(22)
#define MESON_SAR_ADC_REG3_ADC_EN BIT(21)
#define MESON_SAR_ADC_REG3_PANEL_DETECT_COUNT_MASK GENMASK(20, 18)
#define MESON_SAR_ADC_REG3_PANEL_DETECT_FILTER_TB_MASK GENMASK(17, 16)
#define MESON_SAR_ADC_REG3_ADC_CLK_DIV_SHIFT 10
#define MESON_SAR_ADC_REG3_ADC_CLK_DIV_WIDTH 5
#define MESON_SAR_ADC_REG3_BLOCK_DLY_SEL_MASK GENMASK(9, 8)
#define MESON_SAR_ADC_REG3_BLOCK_DLY_MASK GENMASK(7, 0)
#define MESON_SAR_ADC_DELAY 0x10
#define MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK GENMASK(25, 24)
#define MESON_SAR_ADC_DELAY_BL30_BUSY BIT(15)
#define MESON_SAR_ADC_DELAY_KERNEL_BUSY BIT(14)
#define MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK GENMASK(23, 16)
#define MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK GENMASK(9, 8)
#define MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK GENMASK(7, 0)
#define MESON_SAR_ADC_LAST_RD 0x14
#define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL1_MASK GENMASK(23, 16)
#define MESON_SAR_ADC_LAST_RD_LAST_CHANNEL0_MASK GENMASK(9, 0)
#define MESON_SAR_ADC_FIFO_RD 0x18
#define MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK GENMASK(14, 12)
#define MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK GENMASK(11, 0)
#define MESON_SAR_ADC_AUX_SW 0x1c
#define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(_chan) \
(8 + (((_chan) - 2) * 3))
#define MESON_SAR_ADC_AUX_SW_VREF_P_MUX BIT(6)
#define MESON_SAR_ADC_AUX_SW_VREF_N_MUX BIT(5)
#define MESON_SAR_ADC_AUX_SW_MODE_SEL BIT(4)
#define MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW BIT(3)
#define MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW BIT(2)
#define MESON_SAR_ADC_AUX_SW_YM_DRIVE_SW BIT(1)
#define MESON_SAR_ADC_AUX_SW_XM_DRIVE_SW BIT(0)
#define MESON_SAR_ADC_CHAN_10_SW 0x20
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK GENMASK(25, 23)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_P_MUX BIT(22)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_VREF_N_MUX BIT(21)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_MODE_SEL BIT(20)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YP_DRIVE_SW BIT(19)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XP_DRIVE_SW BIT(18)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_YM_DRIVE_SW BIT(17)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN1_XM_DRIVE_SW BIT(16)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK GENMASK(9, 7)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_P_MUX BIT(6)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_VREF_N_MUX BIT(5)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_MODE_SEL BIT(4)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YP_DRIVE_SW BIT(3)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XP_DRIVE_SW BIT(2)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_YM_DRIVE_SW BIT(1)
#define MESON_SAR_ADC_CHAN_10_SW_CHAN0_XM_DRIVE_SW BIT(0)
#define MESON_SAR_ADC_DETECT_IDLE_SW 0x24
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_SW_EN BIT(26)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK GENMASK(25, 23)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_P_MUX BIT(22)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_VREF_N_MUX BIT(21)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MODE_SEL BIT(20)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YP_DRIVE_SW BIT(19)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XP_DRIVE_SW BIT(18)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_YM_DRIVE_SW BIT(17)
#define MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_XM_DRIVE_SW BIT(16)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK GENMASK(9, 7)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_P_MUX BIT(6)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_VREF_N_MUX BIT(5)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MODE_SEL BIT(4)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YP_DRIVE_SW BIT(3)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XP_DRIVE_SW BIT(2)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_YM_DRIVE_SW BIT(1)
#define MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_XM_DRIVE_SW BIT(0)
#define MESON_SAR_ADC_DELTA_10 0x28
#define MESON_SAR_ADC_DELTA_10_TEMP_SEL BIT(27)
#define MESON_SAR_ADC_DELTA_10_TS_REVE1 BIT(26)
#define MESON_SAR_ADC_DELTA_10_CHAN1_DELTA_VALUE_MASK GENMASK(25, 16)
#define MESON_SAR_ADC_DELTA_10_TS_REVE0 BIT(15)
#define MESON_SAR_ADC_DELTA_10_TS_C_SHIFT 11
#define MESON_SAR_ADC_DELTA_10_TS_C_MASK GENMASK(14, 11)
#define MESON_SAR_ADC_DELTA_10_TS_VBG_EN BIT(10)
#define MESON_SAR_ADC_DELTA_10_CHAN0_DELTA_VALUE_MASK GENMASK(9, 0)
/*
* NOTE: registers from here are undocumented (the vendor Linux kernel driver
* and u-boot source served as reference). These only seem to be relevant on
* GXBB and newer.
*/
#define MESON_SAR_ADC_REG11 0x2c
#define MESON_SAR_ADC_REG11_BANDGAP_EN BIT(13)
#define MESON_SAR_ADC_REG13 0x34
#define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK GENMASK(13, 8)
#define MESON_SAR_ADC_MAX_FIFO_SIZE 32
#define MESON_SAR_ADC_TIMEOUT 100 /* ms */
#define NUM_CHANNELS 8
#define MILLION 1000000
struct meson_saradc_data {
int num_bits;
};
struct meson_saradc_priv {
const struct meson_saradc_data *data;
struct regmap *regmap;
struct clk core_clk;
struct clk adc_clk;
bool initialized;
int active_channel;
int calibbias;
int calibscale;
};
static unsigned int
meson_saradc_get_fifo_count(struct meson_saradc_priv *priv)
{
u32 regval;
regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
}
static int meson_saradc_lock(struct meson_saradc_priv *priv)
{
uint val, timeout = 10000;
/* prevent BL30 from using the SAR ADC while we are using it */
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_KERNEL_BUSY,
MESON_SAR_ADC_DELAY_KERNEL_BUSY);
/*
* wait until BL30 releases it's lock (so we can use the SAR ADC)
*/
do {
udelay(1);
regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
if (timeout < 0) {
printf("Timeout while waiting for BL30 unlock\n");
return -ETIMEDOUT;
}
return 0;
}
static void meson_saradc_unlock(struct meson_saradc_priv *priv)
{
/* allow BL30 to use the SAR ADC again */
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);
}
static void meson_saradc_clear_fifo(struct meson_saradc_priv *priv)
{
unsigned int count, tmp;
for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) {
if (!meson_saradc_get_fifo_count(priv))
break;
regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp);
}
}
static int meson_saradc_calib_val(struct meson_saradc_priv *priv, int val)
{
int tmp;
/* use val_calib = scale * val_raw + offset calibration function */
tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias;
return clamp(tmp, 0, (1 << priv->data->num_bits) - 1);
}
static int meson_saradc_wait_busy_clear(struct meson_saradc_priv *priv)
{
uint regval, timeout = 10000;
/*
* NOTE: we need a small delay before reading the status, otherwise
* the sample engine may not have started internally (which would
* seem to us that sampling is already finished).
*/
do {
udelay(1);
regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
} while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
if (timeout < 0)
return -ETIMEDOUT;
return 0;
}
static int meson_saradc_read_raw_sample(struct meson_saradc_priv *priv,
unsigned int channel, uint *val)
{
uint regval, fifo_chan, fifo_val, count;
int ret;
ret = meson_saradc_wait_busy_clear(priv);
if (ret)
return ret;
count = meson_saradc_get_fifo_count(priv);
if (count != 1) {
printf("ADC FIFO has %d element(s) instead of one\n", count);
return -EINVAL;
}
regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
if (fifo_chan != channel) {
printf("ADC FIFO entry belongs to channel %u instead of %u\n",
fifo_chan, channel);
return -EINVAL;
}
fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
fifo_val &= GENMASK(priv->data->num_bits - 1, 0);
*val = meson_saradc_calib_val(priv, fifo_val);
return 0;
}
static void meson_saradc_start_sample_engine(struct meson_saradc_priv *priv)
{
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_SAMPLING_START,
MESON_SAR_ADC_REG0_SAMPLING_START);
}
static void meson_saradc_stop_sample_engine(struct meson_saradc_priv *priv)
{
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_SAMPLING_STOP,
MESON_SAR_ADC_REG0_SAMPLING_STOP);
/* wait until all modules are stopped */
meson_saradc_wait_busy_clear(priv);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE, 0);
}
enum meson_saradc_avg_mode {
NO_AVERAGING = 0x0,
MEAN_AVERAGING = 0x1,
MEDIAN_AVERAGING = 0x2,
};
enum meson_saradc_num_samples {
ONE_SAMPLE = 0x0,
TWO_SAMPLES = 0x1,
FOUR_SAMPLES = 0x2,
EIGHT_SAMPLES = 0x3,
};
static void meson_saradc_set_averaging(struct meson_saradc_priv *priv,
unsigned int channel,
enum meson_saradc_avg_mode mode,
enum meson_saradc_num_samples samples)
{
int val;
val = samples << MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_SHIFT(channel);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
MESON_SAR_ADC_AVG_CNTL_NUM_SAMPLES_MASK(channel),
val);
val = mode << MESON_SAR_ADC_AVG_CNTL_AVG_MODE_SHIFT(channel);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_AVG_CNTL,
MESON_SAR_ADC_AVG_CNTL_AVG_MODE_MASK(channel), val);
}
static void meson_saradc_enable_channel(struct meson_saradc_priv *priv,
unsigned int channel)
{
uint regval;
/*
* the SAR ADC engine allows sampling multiple channels at the same
* time. to keep it simple we're only working with one *internal*
* channel, which starts counting at index 0 (which means: count = 1).
*/
regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, 0);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
MESON_SAR_ADC_CHAN_LIST_MAX_INDEX_MASK, regval);
/* map channel index 0 to the channel which we want to read */
regval = FIELD_PREP(MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), channel);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_LIST,
MESON_SAR_ADC_CHAN_LIST_ENTRY_MASK(0), regval);
regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
channel);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
MESON_SAR_ADC_DETECT_IDLE_SW_DETECT_MUX_MASK,
regval);
regval = FIELD_PREP(MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
channel);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DETECT_IDLE_SW,
MESON_SAR_ADC_DETECT_IDLE_SW_IDLE_MUX_SEL_MASK,
regval);
if (channel == 6)
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELTA_10,
MESON_SAR_ADC_DELTA_10_TEMP_SEL, 0);
}
static int meson_saradc_get_sample(struct meson_saradc_priv *priv,
int chan, uint *val)
{
int ret;
ret = meson_saradc_lock(priv);
if (ret)
return ret;
/* clear the FIFO to make sure we're not reading old values */
meson_saradc_clear_fifo(priv);
meson_saradc_set_averaging(priv, chan, MEAN_AVERAGING, EIGHT_SAMPLES);
meson_saradc_enable_channel(priv, chan);
meson_saradc_start_sample_engine(priv);
ret = meson_saradc_read_raw_sample(priv, chan, val);
meson_saradc_stop_sample_engine(priv);
meson_saradc_unlock(priv);
if (ret) {
printf("failed to read sample for channel %d: %d\n",
chan, ret);
return ret;
}
return 0;
}
static int meson_saradc_channel_data(struct udevice *dev, int channel,
unsigned int *data)
{
struct meson_saradc_priv *priv = dev_get_priv(dev);
if (channel != priv->active_channel) {
pr_err("Requested channel is not active!");
return -EINVAL;
}
return meson_saradc_get_sample(priv, channel, data);
}
enum meson_saradc_chan7_mux_sel {
CHAN7_MUX_VSS = 0x0,
CHAN7_MUX_VDD_DIV4 = 0x1,
CHAN7_MUX_VDD_DIV2 = 0x2,
CHAN7_MUX_VDD_MUL3_DIV4 = 0x3,
CHAN7_MUX_VDD = 0x4,
CHAN7_MUX_CH7_INPUT = 0x7,
};
static void meson_saradc_set_chan7_mux(struct meson_saradc_priv *priv,
enum meson_saradc_chan7_mux_sel sel)
{
u32 regval;
regval = FIELD_PREP(MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, sel);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
udelay(20);
}
static int meson_saradc_calib(struct meson_saradc_priv *priv)
{
uint nominal0, nominal1, value0, value1;
int ret;
/* use points 25% and 75% for calibration */
nominal0 = (1 << priv->data->num_bits) / 4;
nominal1 = (1 << priv->data->num_bits) * 3 / 4;
meson_saradc_set_chan7_mux(priv, CHAN7_MUX_VDD_DIV4);
udelay(20);
ret = meson_saradc_get_sample(priv, 7, &value0);
if (ret < 0)
goto out;
meson_saradc_set_chan7_mux(priv, CHAN7_MUX_VDD_MUL3_DIV4);
udelay(20);
ret = meson_saradc_get_sample(priv, 7, &value1);
if (ret < 0)
goto out;
if (value1 <= value0) {
ret = -EINVAL;
goto out;
}
priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
value1 - value0);
priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
MILLION);
ret = 0;
out:
meson_saradc_set_chan7_mux(priv, CHAN7_MUX_CH7_INPUT);
return ret;
}
static int meson_saradc_init(struct meson_saradc_priv *priv)
{
uint regval;
int ret, i;
priv->calibscale = MILLION;
/*
* make sure we start at CH7 input since the other muxes are only used
* for internal calibration.
*/
meson_saradc_set_chan7_mux(priv, CHAN7_MUX_CH7_INPUT);
/*
* leave sampling delay and the input clocks as configured by
* BL30 to make sure BL30 gets the values it expects when
* reading the temperature sensor.
*/
regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED) {
regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
if (regval & MESON_SAR_ADC_REG3_ADC_EN)
return 0;
}
meson_saradc_stop_sample_engine(priv);
/* update the channel 6 MUX to select the temperature sensor */
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL,
MESON_SAR_ADC_REG0_ADC_TEMP_SEN_SEL);
/* disable all channels by default */
regmap_write(priv->regmap, MESON_SAR_ADC_CHAN_LIST, 0x0);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
MESON_SAR_ADC_REG3_CTRL_SAMPLING_CLOCK_PHASE, 0);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY,
MESON_SAR_ADC_REG3_CNTL_USE_SC_DLY);
/* delay between two samples = (10+1) * 1uS */
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_CNT_MASK,
10));
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
FIELD_PREP(MESON_SAR_ADC_DELAY_SAMPLE_DLY_SEL_MASK,
0));
/* delay between two samples = (10+1) * 1uS */
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_CNT_MASK,
10));
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK,
1));
/*
* set up the input channel muxes in MESON_SAR_ADC_CHAN_10_SW
* (0 = SAR_ADC_CH0, 1 = SAR_ADC_CH1)
*/
regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, 0);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK,
regval);
regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, 1);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW,
MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK,
regval);
/*
* set up the input channel muxes in MESON_SAR_ADC_AUX_SW
* (2 = SAR_ADC_CH2, 3 = SAR_ADC_CH3, ...) and enable
* MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW and
* MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW like the vendor driver.
*/
regval = 0;
for (i = 2; i <= 7; i++)
regval |= i << MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(i);
regval |= MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW;
regval |= MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW;
regmap_write(priv->regmap, MESON_SAR_ADC_AUX_SW, regval);
ret = meson_saradc_lock(priv);
if (ret)
return ret;
#if CONFIG_IS_ENABLED(CLK)
ret = clk_enable(&priv->core_clk);
if (ret)
return ret;
#endif
regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
MESON_SAR_ADC_REG11_BANDGAP_EN,
MESON_SAR_ADC_REG11_BANDGAP_EN);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
MESON_SAR_ADC_REG3_ADC_EN,
MESON_SAR_ADC_REG3_ADC_EN);
udelay(5);
#if CONFIG_IS_ENABLED(CLK)
ret = clk_enable(&priv->adc_clk);
if (ret)
return ret;
#endif
meson_saradc_unlock(priv);
ret = meson_saradc_calib(priv);
if (ret) {
printf("calibration failed\n");
return -EIO;
}
return 0;
}
static int meson_saradc_start_channel(struct udevice *dev, int channel)
{
struct meson_saradc_priv *priv = dev_get_priv(dev);
if (channel < 0 || channel >= NUM_CHANNELS) {
printf("Requested channel is invalid!");
return -EINVAL;
}
if (!priv->initialized) {
int ret;
ret = meson_saradc_init(priv);
if (ret)
return ret;
priv->initialized = true;
}
priv->active_channel = channel;
return 0;
}
static int meson_saradc_stop(struct udevice *dev)
{
struct meson_saradc_priv *priv = dev_get_priv(dev);
priv->active_channel = -1;
return 0;
}
static int meson_saradc_probe(struct udevice *dev)
{
struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
struct meson_saradc_priv *priv = dev_get_priv(dev);
struct udevice *vref;
int vref_uv;
int ret;
ret = regmap_init_mem(dev_ofnode(dev), &priv->regmap);
if (ret)
return ret;
#if CONFIG_IS_ENABLED(CLK)
ret = clk_get_by_name(dev, "core", &priv->core_clk);
if (ret)
return ret;
ret = clk_get_by_name(dev, "adc_clk", &priv->adc_clk);
if (ret)
return ret;
#endif
priv->active_channel = -1;
ret = device_get_supply_regulator(dev, "vref-supply", &vref);
if (ret) {
printf("can't get vref-supply: %d\n", ret);
return ret;
}
vref_uv = regulator_get_value(vref);
if (vref_uv < 0) {
printf("can't get vref-supply value: %d\n", vref_uv);
return vref_uv;
}
/* VDD supplied by common vref pin */
uc_pdata->vdd_supply = vref;
uc_pdata->vdd_microvolts = vref_uv;
uc_pdata->vss_microvolts = 0;
return 0;
}
int meson_saradc_of_to_plat(struct udevice *dev)
{
struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
struct meson_saradc_priv *priv = dev_get_priv(dev);
priv->data = (struct meson_saradc_data *)dev_get_driver_data(dev);
uc_pdata->data_mask = GENMASK(priv->data->num_bits - 1, 0);
uc_pdata->data_format = ADC_DATA_FORMAT_BIN;
uc_pdata->data_timeout_us = MESON_SAR_ADC_TIMEOUT * 1000;
uc_pdata->channel_mask = GENMASK(NUM_CHANNELS - 1, 0);
return 0;
}
static const struct adc_ops meson_saradc_ops = {
.start_channel = meson_saradc_start_channel,
.channel_data = meson_saradc_channel_data,
.stop = meson_saradc_stop,
};
static const struct meson_saradc_data gxbb_saradc_data = {
.num_bits = 10,
};
static const struct meson_saradc_data gxl_saradc_data = {
.num_bits = 12,
};
static const struct udevice_id meson_saradc_ids[] = {
{ .compatible = "amlogic,meson-gxbb-saradc",
.data = (ulong)&gxbb_saradc_data },
{ .compatible = "amlogic,meson-gxl-saradc",
.data = (ulong)&gxl_saradc_data },
{ .compatible = "amlogic,meson-gxm-saradc",
.data = (ulong)&gxl_saradc_data },
{ .compatible = "amlogic,meson-g12a-saradc",
.data = (ulong)&gxl_saradc_data },
{ }
};
U_BOOT_DRIVER(meson_saradc) = {
.name = "meson_saradc",
.id = UCLASS_ADC,
.of_match = meson_saradc_ids,
.ops = &meson_saradc_ops,
.probe = meson_saradc_probe,
.of_to_plat = meson_saradc_of_to_plat,
.priv_auto = sizeof(struct meson_saradc_priv),
};
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