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at91_adc.c
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at91_adc.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for the ADC present in the Atmel AT91 evaluation boards.
*
* Copyright 2011 Free Electrons
*/
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/platform_data/at91_adc.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/pinctrl/consumer.h>
/* Registers */
#define AT91_ADC_CR 0x00 /* Control Register */
#define AT91_ADC_SWRST (1 << 0) /* Software Reset */
#define AT91_ADC_START (1 << 1) /* Start Conversion */
#define AT91_ADC_MR 0x04 /* Mode Register */
#define AT91_ADC_TSAMOD (3 << 0) /* ADC mode */
#define AT91_ADC_TSAMOD_ADC_ONLY_MODE (0 << 0) /* ADC Mode */
#define AT91_ADC_TSAMOD_TS_ONLY_MODE (1 << 0) /* Touch Screen Only Mode */
#define AT91_ADC_TRGEN (1 << 0) /* Trigger Enable */
#define AT91_ADC_TRGSEL (7 << 1) /* Trigger Selection */
#define AT91_ADC_TRGSEL_TC0 (0 << 1)
#define AT91_ADC_TRGSEL_TC1 (1 << 1)
#define AT91_ADC_TRGSEL_TC2 (2 << 1)
#define AT91_ADC_TRGSEL_EXTERNAL (6 << 1)
#define AT91_ADC_LOWRES (1 << 4) /* Low Resolution */
#define AT91_ADC_SLEEP (1 << 5) /* Sleep Mode */
#define AT91_ADC_PENDET (1 << 6) /* Pen contact detection enable */
#define AT91_ADC_PRESCAL_9260 (0x3f << 8) /* Prescalar Rate Selection */
#define AT91_ADC_PRESCAL_9G45 (0xff << 8)
#define AT91_ADC_PRESCAL_(x) ((x) << 8)
#define AT91_ADC_STARTUP_9260 (0x1f << 16) /* Startup Up Time */
#define AT91_ADC_STARTUP_9G45 (0x7f << 16)
#define AT91_ADC_STARTUP_9X5 (0xf << 16)
#define AT91_ADC_STARTUP_(x) ((x) << 16)
#define AT91_ADC_SHTIM (0xf << 24) /* Sample & Hold Time */
#define AT91_ADC_SHTIM_(x) ((x) << 24)
#define AT91_ADC_PENDBC (0x0f << 28) /* Pen Debounce time */
#define AT91_ADC_PENDBC_(x) ((x) << 28)
#define AT91_ADC_TSR 0x0C
#define AT91_ADC_TSR_SHTIM (0xf << 24) /* Sample & Hold Time */
#define AT91_ADC_TSR_SHTIM_(x) ((x) << 24)
#define AT91_ADC_CHER 0x10 /* Channel Enable Register */
#define AT91_ADC_CHDR 0x14 /* Channel Disable Register */
#define AT91_ADC_CHSR 0x18 /* Channel Status Register */
#define AT91_ADC_CH(n) (1 << (n)) /* Channel Number */
#define AT91_ADC_SR 0x1C /* Status Register */
#define AT91_ADC_EOC(n) (1 << (n)) /* End of Conversion on Channel N */
#define AT91_ADC_OVRE(n) (1 << ((n) + 8))/* Overrun Error on Channel N */
#define AT91_ADC_DRDY (1 << 16) /* Data Ready */
#define AT91_ADC_GOVRE (1 << 17) /* General Overrun Error */
#define AT91_ADC_ENDRX (1 << 18) /* End of RX Buffer */
#define AT91_ADC_RXFUFF (1 << 19) /* RX Buffer Full */
#define AT91_ADC_SR_9X5 0x30 /* Status Register for 9x5 */
#define AT91_ADC_SR_DRDY_9X5 (1 << 24) /* Data Ready */
#define AT91_ADC_LCDR 0x20 /* Last Converted Data Register */
#define AT91_ADC_LDATA (0x3ff)
#define AT91_ADC_IER 0x24 /* Interrupt Enable Register */
#define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */
#define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */
#define AT91RL_ADC_IER_PEN (1 << 20)
#define AT91RL_ADC_IER_NOPEN (1 << 21)
#define AT91_ADC_IER_PEN (1 << 29)
#define AT91_ADC_IER_NOPEN (1 << 30)
#define AT91_ADC_IER_XRDY (1 << 20)
#define AT91_ADC_IER_YRDY (1 << 21)
#define AT91_ADC_IER_PRDY (1 << 22)
#define AT91_ADC_ISR_PENS (1 << 31)
#define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */
#define AT91_ADC_DATA (0x3ff)
#define AT91_ADC_CDR0_9X5 (0x50) /* Channel Data Register 0 for 9X5 */
#define AT91_ADC_ACR 0x94 /* Analog Control Register */
#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */
#define AT91_ADC_TSMR 0xB0
#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */
#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0)
#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0)
#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0)
#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0)
#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */
#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4)
#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */
#define AT91_ADC_TSMR_SCTIM_(x) ((x) << 16)
#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */
#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28)
#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */
#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */
#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */
#define AT91_ADC_TSXPOSR 0xB4
#define AT91_ADC_TSYPOSR 0xB8
#define AT91_ADC_TSPRESSR 0xBC
#define AT91_ADC_TRGR_9260 AT91_ADC_MR
#define AT91_ADC_TRGR_9G45 0x08
#define AT91_ADC_TRGR_9X5 0xC0
/* Trigger Register bit field */
#define AT91_ADC_TRGR_TRGPER (0xffff << 16)
#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16)
#define AT91_ADC_TRGR_TRGMOD (0x7 << 0)
#define AT91_ADC_TRGR_NONE (0 << 0)
#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0)
#define AT91_ADC_CHAN(st, ch) \
(st->registers->channel_base + (ch * 4))
#define at91_adc_readl(st, reg) \
(readl_relaxed(st->reg_base + reg))
#define at91_adc_writel(st, reg, val) \
(writel_relaxed(val, st->reg_base + reg))
#define DRIVER_NAME "at91_adc"
#define MAX_POS_BITS 12
#define TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */
#define TOUCH_PEN_DETECT_DEBOUNCE_US 200
#define MAX_RLPOS_BITS 10
#define TOUCH_SAMPLE_PERIOD_US_RL 10000 /* 10ms, the SoC can't keep up with 2ms */
#define TOUCH_SHTIM 0xa
#define TOUCH_SCTIM_US 10 /* 10us for the Touchscreen Switches Closure Time */
/**
* struct at91_adc_reg_desc - Various informations relative to registers
* @channel_base: Base offset for the channel data registers
* @drdy_mask: Mask of the DRDY field in the relevant registers
* (Interruptions registers mostly)
* @status_register: Offset of the Interrupt Status Register
* @trigger_register: Offset of the Trigger setup register
* @mr_prescal_mask: Mask of the PRESCAL field in the adc MR register
* @mr_startup_mask: Mask of the STARTUP field in the adc MR register
*/
struct at91_adc_reg_desc {
u8 channel_base;
u32 drdy_mask;
u8 status_register;
u8 trigger_register;
u32 mr_prescal_mask;
u32 mr_startup_mask;
};
struct at91_adc_caps {
bool has_ts; /* Support touch screen */
bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
/*
* Numbers of sampling data will be averaged. Can be 0~3.
* Hardware can average (2 ^ ts_filter_average) sample data.
*/
u8 ts_filter_average;
/* Pen Detection input pull-up resistor, can be 0~3 */
u8 ts_pen_detect_sensitivity;
/* startup time calculate function */
u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
u8 num_channels;
struct at91_adc_reg_desc registers;
};
struct at91_adc_state {
struct clk *adc_clk;
u16 *buffer;
unsigned long channels_mask;
struct clk *clk;
bool done;
int irq;
u16 last_value;
int chnb;
struct mutex lock;
u8 num_channels;
void __iomem *reg_base;
struct at91_adc_reg_desc *registers;
u32 startup_time;
u8 sample_hold_time;
bool sleep_mode;
struct iio_trigger **trig;
struct at91_adc_trigger *trigger_list;
u32 trigger_number;
bool use_external;
u32 vref_mv;
u32 res; /* resolution used for convertions */
bool low_res; /* the resolution corresponds to the lowest one */
wait_queue_head_t wq_data_avail;
struct at91_adc_caps *caps;
/*
* Following ADC channels are shared by touchscreen:
*
* CH0 -- Touch screen XP/UL
* CH1 -- Touch screen XM/UR
* CH2 -- Touch screen YP/LL
* CH3 -- Touch screen YM/Sense
* CH4 -- Touch screen LR(5-wire only)
*
* The bitfields below represents the reserved channel in the
* touchscreen mode.
*/
#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0)
#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0)
enum atmel_adc_ts_type touchscreen_type;
struct input_dev *ts_input;
u16 ts_sample_period_val;
u32 ts_pressure_threshold;
u16 ts_pendbc;
bool ts_bufferedmeasure;
u32 ts_prev_absx;
u32 ts_prev_absy;
};
static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *idev = pf->indio_dev;
struct at91_adc_state *st = iio_priv(idev);
struct iio_chan_spec const *chan;
int i, j = 0;
for (i = 0; i < idev->masklength; i++) {
if (!test_bit(i, idev->active_scan_mask))
continue;
chan = idev->channels + i;
st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, chan->channel));
j++;
}
iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
iio_trigger_notify_done(idev->trig);
/* Needed to ACK the DRDY interruption */
at91_adc_readl(st, AT91_ADC_LCDR);
enable_irq(st->irq);
return IRQ_HANDLED;
}
/* Handler for classic adc channel eoc trigger */
static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
{
struct at91_adc_state *st = iio_priv(idev);
if (iio_buffer_enabled(idev)) {
disable_irq_nosync(irq);
iio_trigger_poll(idev->trig);
} else {
st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
/* Needed to ACK the DRDY interruption */
at91_adc_readl(st, AT91_ADC_LCDR);
st->done = true;
wake_up_interruptible(&st->wq_data_avail);
}
}
static int at91_ts_sample(struct iio_dev *idev)
{
struct at91_adc_state *st = iio_priv(idev);
unsigned int xscale, yscale, reg, z1, z2;
unsigned int x, y, pres, xpos, ypos;
unsigned int rxp = 1;
unsigned int factor = 1000;
unsigned int xyz_mask_bits = st->res;
unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
/* calculate position */
/* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
xpos = reg & xyz_mask;
x = (xpos << MAX_POS_BITS) - xpos;
xscale = (reg >> 16) & xyz_mask;
if (xscale == 0) {
dev_err(&idev->dev, "Error: xscale == 0!\n");
return -1;
}
x /= xscale;
/* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
ypos = reg & xyz_mask;
y = (ypos << MAX_POS_BITS) - ypos;
yscale = (reg >> 16) & xyz_mask;
if (yscale == 0) {
dev_err(&idev->dev, "Error: yscale == 0!\n");
return -1;
}
y /= yscale;
/* calculate the pressure */
reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
z1 = reg & xyz_mask;
z2 = (reg >> 16) & xyz_mask;
if (z1 != 0)
pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
/ factor;
else
pres = st->ts_pressure_threshold; /* no pen contacted */
dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
xpos, xscale, ypos, yscale, z1, z2, pres);
if (pres < st->ts_pressure_threshold) {
dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
x, y, pres / factor);
input_report_abs(st->ts_input, ABS_X, x);
input_report_abs(st->ts_input, ABS_Y, y);
input_report_abs(st->ts_input, ABS_PRESSURE, pres);
input_report_key(st->ts_input, BTN_TOUCH, 1);
input_sync(st->ts_input);
} else {
dev_dbg(&idev->dev, "pressure too low: not reporting\n");
}
return 0;
}
static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
{
struct iio_dev *idev = private;
struct at91_adc_state *st = iio_priv(idev);
u32 status = at91_adc_readl(st, st->registers->status_register);
unsigned int reg;
status &= at91_adc_readl(st, AT91_ADC_IMR);
if (status & GENMASK(st->num_channels - 1, 0))
handle_adc_eoc_trigger(irq, idev);
if (status & AT91RL_ADC_IER_PEN) {
/* Disabling pen debounce is required to get a NOPEN irq */
reg = at91_adc_readl(st, AT91_ADC_MR);
reg &= ~AT91_ADC_PENDBC;
at91_adc_writel(st, AT91_ADC_MR, reg);
at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
| AT91_ADC_EOC(3));
/* Set up period trigger for sampling */
at91_adc_writel(st, st->registers->trigger_register,
AT91_ADC_TRGR_MOD_PERIOD_TRIG |
AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
} else if (status & AT91RL_ADC_IER_NOPEN) {
reg = at91_adc_readl(st, AT91_ADC_MR);
reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
at91_adc_writel(st, AT91_ADC_MR, reg);
at91_adc_writel(st, st->registers->trigger_register,
AT91_ADC_TRGR_NONE);
at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
| AT91_ADC_EOC(3));
at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
st->ts_bufferedmeasure = false;
input_report_key(st->ts_input, BTN_TOUCH, 0);
input_sync(st->ts_input);
} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
/* Conversion finished and we've a touchscreen */
if (st->ts_bufferedmeasure) {
/*
* Last measurement is always discarded, since it can
* be erroneous.
* Always report previous measurement
*/
input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
input_report_key(st->ts_input, BTN_TOUCH, 1);
input_sync(st->ts_input);
} else
st->ts_bufferedmeasure = true;
/* Now make new measurement */
st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
<< MAX_RLPOS_BITS;
st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
<< MAX_RLPOS_BITS;
st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
}
return IRQ_HANDLED;
}
static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
{
struct iio_dev *idev = private;
struct at91_adc_state *st = iio_priv(idev);
u32 status = at91_adc_readl(st, st->registers->status_register);
const uint32_t ts_data_irq_mask =
AT91_ADC_IER_XRDY |
AT91_ADC_IER_YRDY |
AT91_ADC_IER_PRDY;
if (status & GENMASK(st->num_channels - 1, 0))
handle_adc_eoc_trigger(irq, idev);
if (status & AT91_ADC_IER_PEN) {
at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
ts_data_irq_mask);
/* Set up period trigger for sampling */
at91_adc_writel(st, st->registers->trigger_register,
AT91_ADC_TRGR_MOD_PERIOD_TRIG |
AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
} else if (status & AT91_ADC_IER_NOPEN) {
at91_adc_writel(st, st->registers->trigger_register, 0);
at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
ts_data_irq_mask);
at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
input_report_key(st->ts_input, BTN_TOUCH, 0);
input_sync(st->ts_input);
} else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
/* Now all touchscreen data is ready */
if (status & AT91_ADC_ISR_PENS) {
/* validate data by pen contact */
at91_ts_sample(idev);
} else {
/* triggered by event that is no pen contact, just read
* them to clean the interrupt and discard all.
*/
at91_adc_readl(st, AT91_ADC_TSXPOSR);
at91_adc_readl(st, AT91_ADC_TSYPOSR);
at91_adc_readl(st, AT91_ADC_TSPRESSR);
}
}
return IRQ_HANDLED;
}
static int at91_adc_channel_init(struct iio_dev *idev)
{
struct at91_adc_state *st = iio_priv(idev);
struct iio_chan_spec *chan_array, *timestamp;
int bit, idx = 0;
unsigned long rsvd_mask = 0;
/* If touchscreen is enable, then reserve the adc channels */
if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
/* set up the channel mask to reserve touchscreen channels */
st->channels_mask &= ~rsvd_mask;
idev->num_channels = bitmap_weight(&st->channels_mask,
st->num_channels) + 1;
chan_array = devm_kzalloc(&idev->dev,
((idev->num_channels + 1) *
sizeof(struct iio_chan_spec)),
GFP_KERNEL);
if (!chan_array)
return -ENOMEM;
for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
struct iio_chan_spec *chan = chan_array + idx;
chan->type = IIO_VOLTAGE;
chan->indexed = 1;
chan->channel = bit;
chan->scan_index = idx;
chan->scan_type.sign = 'u';
chan->scan_type.realbits = st->res;
chan->scan_type.storagebits = 16;
chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
idx++;
}
timestamp = chan_array + idx;
timestamp->type = IIO_TIMESTAMP;
timestamp->channel = -1;
timestamp->scan_index = idx;
timestamp->scan_type.sign = 's';
timestamp->scan_type.realbits = 64;
timestamp->scan_type.storagebits = 64;
idev->channels = chan_array;
return idev->num_channels;
}
static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
struct at91_adc_trigger *triggers,
const char *trigger_name)
{
struct at91_adc_state *st = iio_priv(idev);
int i;
for (i = 0; i < st->trigger_number; i++) {
char *name = kasprintf(GFP_KERNEL,
"%s-dev%d-%s",
idev->name,
idev->id,
triggers[i].name);
if (!name)
return -ENOMEM;
if (strcmp(trigger_name, name) == 0) {
kfree(name);
if (triggers[i].value == 0)
return -EINVAL;
return triggers[i].value;
}
kfree(name);
}
return -EINVAL;
}
static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
{
struct iio_dev *idev = iio_trigger_get_drvdata(trig);
struct at91_adc_state *st = iio_priv(idev);
struct at91_adc_reg_desc *reg = st->registers;
u32 status = at91_adc_readl(st, reg->trigger_register);
int value;
u8 bit;
value = at91_adc_get_trigger_value_by_name(idev,
st->trigger_list,
idev->trig->name);
if (value < 0)
return value;
if (state) {
st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
if (st->buffer == NULL)
return -ENOMEM;
at91_adc_writel(st, reg->trigger_register,
status | value);
for_each_set_bit(bit, idev->active_scan_mask,
st->num_channels) {
struct iio_chan_spec const *chan = idev->channels + bit;
at91_adc_writel(st, AT91_ADC_CHER,
AT91_ADC_CH(chan->channel));
}
at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
} else {
at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
at91_adc_writel(st, reg->trigger_register,
status & ~value);
for_each_set_bit(bit, idev->active_scan_mask,
st->num_channels) {
struct iio_chan_spec const *chan = idev->channels + bit;
at91_adc_writel(st, AT91_ADC_CHDR,
AT91_ADC_CH(chan->channel));
}
kfree(st->buffer);
}
return 0;
}
static const struct iio_trigger_ops at91_adc_trigger_ops = {
.set_trigger_state = &at91_adc_configure_trigger,
};
static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
struct at91_adc_trigger *trigger)
{
struct iio_trigger *trig;
int ret;
trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
idev->id, trigger->name);
if (trig == NULL)
return NULL;
trig->dev.parent = idev->dev.parent;
iio_trigger_set_drvdata(trig, idev);
trig->ops = &at91_adc_trigger_ops;
ret = iio_trigger_register(trig);
if (ret)
return NULL;
return trig;
}
static int at91_adc_trigger_init(struct iio_dev *idev)
{
struct at91_adc_state *st = iio_priv(idev);
int i, ret;
st->trig = devm_kcalloc(&idev->dev,
st->trigger_number, sizeof(*st->trig),
GFP_KERNEL);
if (st->trig == NULL) {
ret = -ENOMEM;
goto error_ret;
}
for (i = 0; i < st->trigger_number; i++) {
if (st->trigger_list[i].is_external && !(st->use_external))
continue;
st->trig[i] = at91_adc_allocate_trigger(idev,
st->trigger_list + i);
if (st->trig[i] == NULL) {
dev_err(&idev->dev,
"Could not allocate trigger %d\n", i);
ret = -ENOMEM;
goto error_trigger;
}
}
return 0;
error_trigger:
for (i--; i >= 0; i--) {
iio_trigger_unregister(st->trig[i]);
iio_trigger_free(st->trig[i]);
}
error_ret:
return ret;
}
static void at91_adc_trigger_remove(struct iio_dev *idev)
{
struct at91_adc_state *st = iio_priv(idev);
int i;
for (i = 0; i < st->trigger_number; i++) {
iio_trigger_unregister(st->trig[i]);
iio_trigger_free(st->trig[i]);
}
}
static int at91_adc_buffer_init(struct iio_dev *idev)
{
return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
&at91_adc_trigger_handler, NULL);
}
static void at91_adc_buffer_remove(struct iio_dev *idev)
{
iio_triggered_buffer_cleanup(idev);
}
static int at91_adc_read_raw(struct iio_dev *idev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct at91_adc_state *st = iio_priv(idev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&st->lock);
st->chnb = chan->channel;
at91_adc_writel(st, AT91_ADC_CHER,
AT91_ADC_CH(chan->channel));
at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
ret = wait_event_interruptible_timeout(st->wq_data_avail,
st->done,
msecs_to_jiffies(1000));
/* Disable interrupts, regardless if adc conversion was
* successful or not
*/
at91_adc_writel(st, AT91_ADC_CHDR,
AT91_ADC_CH(chan->channel));
at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
if (ret > 0) {
/* a valid conversion took place */
*val = st->last_value;
st->last_value = 0;
st->done = false;
ret = IIO_VAL_INT;
} else if (ret == 0) {
/* conversion timeout */
dev_err(&idev->dev, "ADC Channel %d timeout.\n",
chan->channel);
ret = -ETIMEDOUT;
}
mutex_unlock(&st->lock);
return ret;
case IIO_CHAN_INFO_SCALE:
*val = st->vref_mv;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
static int at91_adc_of_get_resolution(struct iio_dev *idev,
struct platform_device *pdev)
{
struct at91_adc_state *st = iio_priv(idev);
struct device_node *np = pdev->dev.of_node;
int count, i, ret = 0;
char *res_name, *s;
u32 *resolutions;
count = of_property_count_strings(np, "atmel,adc-res-names");
if (count < 2) {
dev_err(&idev->dev, "You must specified at least two resolution names for "
"adc-res-names property in the DT\n");
return count;
}
resolutions = kmalloc_array(count, sizeof(*resolutions), GFP_KERNEL);
if (!resolutions)
return -ENOMEM;
if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
ret = -ENODEV;
goto ret;
}
if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
res_name = "highres";
for (i = 0; i < count; i++) {
if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
continue;
if (strcmp(res_name, s))
continue;
st->res = resolutions[i];
if (!strcmp(res_name, "lowres"))
st->low_res = true;
else
st->low_res = false;
dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
goto ret;
}
dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
ret:
kfree(resolutions);
return ret;
}
static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
{
/*
* Number of ticks needed to cover the startup time of the ADC
* as defined in the electrical characteristics of the board,
* divided by 8. The formula thus is :
* Startup Time = (ticks + 1) * 8 / ADC Clock
*/
return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
}
static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
{
/*
* For sama5d3x and at91sam9x5, the formula changes to:
* Startup Time = <lookup_table_value> / ADC Clock
*/
static const int startup_lookup[] = {
0, 8, 16, 24,
64, 80, 96, 112,
512, 576, 640, 704,
768, 832, 896, 960
};
int i, size = ARRAY_SIZE(startup_lookup);
unsigned int ticks;
ticks = startup_time * adc_clk_khz / 1000;
for (i = 0; i < size; i++)
if (ticks < startup_lookup[i])
break;
ticks = i;
if (ticks == size)
/* Reach the end of lookup table */
ticks = size - 1;
return ticks;
}
static const struct of_device_id at91_adc_dt_ids[];
static int at91_adc_probe_dt_ts(struct device_node *node,
struct at91_adc_state *st, struct device *dev)
{
int ret;
u32 prop;
ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
if (ret) {
dev_info(dev, "ADC Touch screen is disabled.\n");
return 0;
}
switch (prop) {
case 4:
case 5:
st->touchscreen_type = prop;
break;
default:
dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
return -EINVAL;
}
if (!st->caps->has_tsmr)
return 0;
prop = 0;
of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
st->ts_pressure_threshold = prop;
if (st->ts_pressure_threshold) {
return 0;
} else {
dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
return -EINVAL;
}
}
static int at91_adc_probe_dt(struct iio_dev *idev,
struct platform_device *pdev)
{
struct at91_adc_state *st = iio_priv(idev);
struct device_node *node = pdev->dev.of_node;
struct device_node *trig_node;
int i = 0, ret;
u32 prop;
if (!node)
return -EINVAL;
st->caps = (struct at91_adc_caps *)
of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
ret = -EINVAL;
goto error_ret;
}
st->channels_mask = prop;
st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
ret = -EINVAL;
goto error_ret;
}
st->startup_time = prop;
prop = 0;
of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
st->sample_hold_time = prop;
if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
ret = -EINVAL;
goto error_ret;
}
st->vref_mv = prop;
ret = at91_adc_of_get_resolution(idev, pdev);
if (ret)
goto error_ret;
st->registers = &st->caps->registers;
st->num_channels = st->caps->num_channels;
st->trigger_number = of_get_child_count(node);
st->trigger_list = devm_kcalloc(&idev->dev,
st->trigger_number,
sizeof(struct at91_adc_trigger),
GFP_KERNEL);
if (!st->trigger_list) {
dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
ret = -ENOMEM;
goto error_ret;
}
for_each_child_of_node(node, trig_node) {
struct at91_adc_trigger *trig = st->trigger_list + i;
const char *name;
if (of_property_read_string(trig_node, "trigger-name", &name)) {
dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
ret = -EINVAL;
goto error_ret;
}
trig->name = name;
if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
ret = -EINVAL;
goto error_ret;
}
trig->value = prop;
trig->is_external = of_property_read_bool(trig_node, "trigger-external");
i++;
}
/* Check if touchscreen is supported. */
if (st->caps->has_ts)
return at91_adc_probe_dt_ts(node, st, &idev->dev);
else
dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
return 0;
error_ret:
return ret;
}
static int at91_adc_probe_pdata(struct at91_adc_state *st,
struct platform_device *pdev)
{
struct at91_adc_data *pdata = pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
st->caps = (struct at91_adc_caps *)
platform_get_device_id(pdev)->driver_data;
st->use_external = pdata->use_external_triggers;
st->vref_mv = pdata->vref;
st->channels_mask = pdata->channels_used;
st->num_channels = st->caps->num_channels;
st->startup_time = pdata->startup_time;
st->trigger_number = pdata->trigger_number;
st->trigger_list = pdata->trigger_list;
st->registers = &st->caps->registers;
st->touchscreen_type = pdata->touchscreen_type;
return 0;
}
static const struct iio_info at91_adc_info = {
.read_raw = &at91_adc_read_raw,
};
/* Touchscreen related functions */
static int atmel_ts_open(struct input_dev *dev)
{
struct at91_adc_state *st = input_get_drvdata(dev);
if (st->caps->has_tsmr)
at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
else
at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
return 0;