On 12/19/2012 05:01 PM, Marek Vasut wrote:
> Ccing Dmitry.
>
> Also, Jonathan, can I get your review please?
Dratt caught me hiding from this one and hoping it would
go away ;)
>
>> This patch implements support for sampling of a touchscreen into
>> the MXS LRADC driver. The LRADC block allows configuring some of
>> it's channels into special mode where they either output the drive
>> voltage or sample it, allowing it to operate a 4-wire or 5-wire
>> resistive touchscreen.
>>
>> In case the touchscreen mode is enabled, the LRADC slot #7 is
>> reserved for touchscreen only, therefore it is not possible to
>> sample 8 LRADC channels at time, but only 7 channels.
>>
>> The touchscreen controller is configured such that the PENDOWN event
>> disables touchscreen interrupts and triggers execution of worker
>> thread, which then polls the touchscreen controller for X, Y and
>> Pressure values. This reduces the overhead of interrupt-driven
>> operation. Upon the PENUP event, the worker thread re-enables the
>> PENDOWN detection interrupt and exits.
>>
>> Signed-off-by: Marek Vasut <marex@xxxxxxx>
>> Cc: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
>> Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
>> Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
>> ---
>> .../bindings/staging/iio/adc/mxs-lradc.txt | 6 +
>> drivers/staging/iio/adc/mxs-lradc.c | 469
>> +++++++++++++++++++- 2 files changed, 454 insertions(+), 21 deletions(-)
>>
>> V2: - Replace the use_touchscreen* with enum mxs_lradc_ts, which now tracks
>> touchscreen state (OFF, 4-wire, 5-wire)
>> - Add "stop_touchscreen" bit, which indicates the touchscreen is going
>> down and makes the driver not re-enable touchscreen interrupts and start
>> any new touchscreen works.
>> - Make all bitfields "unsigned int" instead of plain "int"
>> - Use switch(plate) in mxs_lradc_ts_sample()
>> - Cancel touchscreen thread in mxs_lradc_ts_close(), do this only after
>> we are sure touchscreen interrupt is off and will never be
>> re-enabled. This avoids serious race condition.
>> - Call input_free_device() if input_register_device() fails to avoid
>> memory leak.
>> - Do not call input_free_device() after input_unregister_device() in
>> mxs_lradc_ts_unregister() to avoid double-free
>>
>> diff --git
>> a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
>> b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt index
>> 801d58c..4688205 100644
>> --- a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
>> +++ b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
>> @@ -5,6 +5,12 @@ Required properties:
>> - reg: Address and length of the register set for the device
>> - interrupts: Should contain the LRADC interrupts
>>
>> +Optional properties:
>> +- fsl,lradc-touchscreen-wires: Number of wires used to connect the
>> touchscreen + to LRADC. Valid value is
>> either 4 or 5. If this + property is not
>> present, then the touchscreen is + disabled.
>> +
>> Examples:
>>
>> lradc@80050000 {
>> diff --git a/drivers/staging/iio/adc/mxs-lradc.c
>> b/drivers/staging/iio/adc/mxs-lradc.c index 6249957..52317ef 100644
>> --- a/drivers/staging/iio/adc/mxs-lradc.c
>> +++ b/drivers/staging/iio/adc/mxs-lradc.c
>> @@ -32,6 +32,8 @@
>> #include <linux/stmp_device.h>
>> #include <linux/bitops.h>
>> #include <linux/completion.h>
>> +#include <linux/delay.h>
>> +#include <linux/input.h>
>>
>> #include <mach/mxs.h>
>> #include <mach/common.h>
>> @@ -59,6 +61,21 @@
>> #define LRADC_DELAY_TIMER_PER 200
>> #define LRADC_DELAY_TIMER_LOOP 5
>>
>> +/*
>> + * Once the pen touches the touchscreen, the touchscreen switches from
>> + * IRQ-driven mode to polling mode to prevent interrupt storm. The polling
>> + * is realized by worker thread, which is called every 20 or so
>> milliseconds. + * This gives the touchscreen enough fluence and does not
>> strain the system + * too much.
>> + */
>> +#define LRADC_TS_SAMPLE_DELAY_MS 5
>> +
>> +/*
>> + * The LRADC reads the following amount of samples from each touchscreen
>> + * channel and the driver then computes avarage of these.
>> + */
>> +#define LRADC_TS_SAMPLE_AMOUNT 4
>> +
>> static const char * const mxs_lradc_irq_name[] = {
>> "mxs-lradc-touchscreen",
>> "mxs-lradc-thresh0",
>> @@ -75,6 +92,12 @@ static const char * const mxs_lradc_irq_name[] = {
>> "mxs-lradc-button1",
>> };
>>
>> +enum mxs_lradc_ts {
>> + MXS_LRADC_TOUCHSCREEN_NONE = 0,
>> + MXS_LRADC_TOUCHSCREEN_4WIRE,
>> + MXS_LRADC_TOUCHSCREEN_5WIRE,
>> +};
>> +
>> struct mxs_lradc {
>> struct device *dev;
>> void __iomem *base;
>> @@ -86,21 +109,69 @@ struct mxs_lradc {
>> struct mutex lock;
>>
>> struct completion completion;
>> +
>> + /*
>> + * Touchscreen LRADC channels receives a private slot in the CTRL4
>> + * register, the slot #7. Therefore only 7 slots instead of 8 in the
>> + * CTRL4 register can be mapped to LRADC channels when using the
>> + * touchscreen.
>> + *
>> + * Furthermore, certain LRADC channels are shared between touchscreen
>> + * and/or touch-buttons and generic LRADC block. Therefore when using
>> + * either of these, these channels are not available for the regular
>> + * sampling. The shared channels are as follows:
>> + *
>> + * CH0 -- Touch button #0
>> + * CH1 -- Touch button #1
>> + * CH2 -- Touch screen XPUL
>> + * CH3 -- Touch screen YPLL
>> + * CH4 -- Touch screen XNUL
>> + * CH5 -- Touch screen YNLR
>> + * CH6 -- Touch screen WIPER (5-wire only)
>> + *
>> + * The bitfields below represents which parts of the LRADC block are
>> + * switched into special mode of operation. These channels can not
>> + * be sampled as regular LRADC channels. The driver will refuse any
>> + * attempt to sample these channels.
>> + */
>> +#define CHAN_MASK_TOUCHBUTTON (0x3 << 0)
>> +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2)
>> +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2)
>> + enum mxs_lradc_ts use_touchscreen;
>> + unsigned int stop_touchscreen:1;
>> + unsigned int use_touchbutton:1;
>> +
>> + struct input_dev *ts_input;
>> + struct work_struct ts_work;
>> };
>>
>> #define LRADC_CTRL0 0x00
>> -#define LRADC_CTRL0_TOUCH_DETECT_ENABLE (1 << 23)
>> -#define LRADC_CTRL0_TOUCH_SCREEN_TYPE (1 << 22)
>> +#define LRADC_CTRL0_TOUCH_DETECT_ENABLE (1 << 23)
>> +#define LRADC_CTRL0_TOUCH_SCREEN_TYPE (1 << 22)
>> +#define LRADC_CTRL0_YNNSW /* YM */ (1 << 21)
>> +#define LRADC_CTRL0_YPNSW /* YP */ (1 << 20)
>> +#define LRADC_CTRL0_YPPSW /* YP */ (1 << 19)
>> +#define LRADC_CTRL0_XNNSW /* XM */ (1 << 18)
>> +#define LRADC_CTRL0_XNPSW /* XM */ (1 << 17)
>> +#define LRADC_CTRL0_XPPSW /* XP */ (1 << 16)
>> +#define LRADC_CTRL0_PLATE_MASK (0x3f << 16)
>>
>> #define LRADC_CTRL1 0x10
>> -#define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n))
>> -#define LRADC_CTRL1_LRADC_IRQ_MASK 0x1fff
>> +#define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN (1 << 24)
>> #define LRADC_CTRL1_LRADC_IRQ_EN(n) (1 << ((n) + 16))
>> #define LRADC_CTRL1_LRADC_IRQ_EN_MASK (0x1fff << 16)
>> +#define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET 16
>> +#define LRADC_CTRL1_TOUCH_DETECT_IRQ (1 << 8)
>> +#define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n))
>> +#define LRADC_CTRL1_LRADC_IRQ_MASK 0x1fff
>> +#define LRADC_CTRL1_LRADC_IRQ_OFFSET 0
>>
>> #define LRADC_CTRL2 0x20
>> #define LRADC_CTRL2_TEMPSENSE_PWD (1 << 15)
>>
>> +#define LRADC_STATUS 0x40
>> +#define LRADC_STATUS_TOUCH_DETECT_RAW (1 << 0)
>> +
>> #define LRADC_CH(n) (0x50 + (0x10 * (n)))
>> #define LRADC_CH_ACCUMULATE (1 << 29)
>> #define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24)
>> @@ -132,6 +203,7 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> {
>> struct mxs_lradc *lradc = iio_priv(iio_dev);
>> int ret;
>> + unsigned long mask;
>>
>> if (m != IIO_CHAN_INFO_RAW)
>> return -EINVAL;
>> @@ -140,6 +212,12 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>> return -EINVAL;
>>
>> + /* Validate the channel if it doesn't intersect with reserved chans. */
>> + bitmap_set(&mask, chan->channel, 1);
>> + ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
>> + if (ret)
>> + return -EINVAL;
>> +
>> /*
>> * See if there is no buffered operation in progess. If there is, simply
>> * bail out. This can be improved to support both buffered and raw IO at
>> @@ -161,7 +239,11 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
>> writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>>
>> - writel(chan->channel, lradc->base + LRADC_CTRL4);
>> + /* Clean the slot's previous content, then set new one. */
>> + writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
>> + lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
>> + writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>> +
>> writel(0, lradc->base + LRADC_CH(0));
>>
>> /* Enable the IRQ and start sampling the channel. */
>> @@ -195,6 +277,272 @@ static const struct iio_info mxs_lradc_iio_info = {
>> };
>>
>> /*
>> + * Touchscreen handling
>> + */
>> +enum lradc_ts_plate {
>> + LRADC_SAMPLE_X,
>> + LRADC_SAMPLE_Y,
>> + LRADC_SAMPLE_PRESSURE,
>> +};
>> +
>> +static int mxs_lradc_ts_touched(struct mxs_lradc *lradc)
>> +{
>> + uint32_t reg;
>> +
>> + /* Enable touch detection. */
>> + writel(LRADC_CTRL0_PLATE_MASK,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>> + writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
>> +
>> + msleep(LRADC_TS_SAMPLE_DELAY_MS);
>> +
>> + reg = readl(lradc->base + LRADC_STATUS);
>> +
>> + return reg & LRADC_STATUS_TOUCH_DETECT_RAW;
>> +}
>> +
>> +static int32_t mxs_lradc_ts_sample(struct mxs_lradc *lradc,
>> + enum lradc_ts_plate plate, int change)
>> +{
>> + unsigned long delay, jiff;
>> + uint32_t reg, ctrl0 = 0, chan = 0;
>> + /* The touchscreen always uses CTRL4 slot #7. */
>> + const uint8_t slot = 7;
>> + uint32_t val;
>> +
>> + /*
>> + * There are three correct configurations of the controller sampling
>> + * the touchscreen, each of these configuration provides different
>> + * information from the touchscreen.
>> + *
>> + * The following table describes the sampling configurations:
>> + * +-------------+-------+-------+-------+
>> + * | Wire \ Axis | X | Y | Z |
>> + * +---------------------+-------+-------+
>> + * | X+ (CH2) | HI | TS | TS |
>> + * +-------------+-------+-------+-------+
>> + * | X- (CH4) | LO | SH | HI |
>> + * +-------------+-------+-------+-------+
>> + * | Y+ (CH3) | SH | HI | HI |
>> + * +-------------+-------+-------+-------+
>> + * | Y- (CH5) | TS | LO | SH |
>> + * +-------------+-------+-------+-------+
>> + *
>> + * HI ... strong '1' ; LO ... strong '0'
>> + * SH ... sample here ; TS ... tri-state
>> + *
>> + * There are a few other ways of obtaining the Z coordinate
>> + * (aka. pressure), but the one in the table seems to be the
>> + * most reliable one.
>> + */
>> + switch (plate) {
>> + case LRADC_SAMPLE_X:
>> + ctrl0 = LRADC_CTRL0_XPPSW | LRADC_CTRL0_XNNSW;
>> + chan = 3;
>> + break;
>> + case LRADC_SAMPLE_Y:
>> + ctrl0 = LRADC_CTRL0_YPPSW | LRADC_CTRL0_YNNSW;
>> + chan = 4;
>> + break;
>> + case LRADC_SAMPLE_PRESSURE:
>> + ctrl0 = LRADC_CTRL0_YPPSW | LRADC_CTRL0_XNNSW;
>> + chan = 5;
>> + break;
>> + }
>> +
>> + if (change) {
>> + writel(LRADC_CTRL0_PLATE_MASK,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>> + writel(ctrl0, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
>> +
>> + writel(LRADC_CTRL4_LRADCSELECT_MASK(slot),
>> + lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
>> + writel(chan << LRADC_CTRL4_LRADCSELECT_OFFSET(slot),
>> + lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>> + }
>> +
>> + writel(0xffffffff, lradc->base + LRADC_CH(slot) + STMP_OFFSET_REG_CLR);
>> + writel(1 << slot, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
>> +
>> + delay = jiffies + msecs_to_jiffies(LRADC_TS_SAMPLE_DELAY_MS);
>> + do {
>> + jiff = jiffies;
>> + reg = readl_relaxed(lradc->base + LRADC_CTRL1);
>> + if (reg & LRADC_CTRL1_LRADC_IRQ(slot))
>> + break;
>> + } while (time_before(jiff, delay));
>> +
>> + writel(LRADC_CTRL1_LRADC_IRQ(slot),
>> + lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
>> +
>> + if (time_after_eq(jiff, delay))
>> + return -ETIMEDOUT;
>> +
>> + val = readl(lradc->base + LRADC_CH(slot));
>> + val &= LRADC_CH_VALUE_MASK;
>> +
>> + return val;
>> +}
>> +
>> +static int32_t mxs_lradc_ts_sample_filter(struct mxs_lradc *lradc,
>> + enum lradc_ts_plate plate)
>> +{
>> + int32_t val, tot = 0;
>> + int i;
>> +
>> + val = mxs_lradc_ts_sample(lradc, plate, 1);
>> +
>> + /* Delay a bit so the touchscreen is stable. */
>> + mdelay(2);
>> +
>> + for (i = 0; i < LRADC_TS_SAMPLE_AMOUNT; i++) {
>> + val = mxs_lradc_ts_sample(lradc, plate, 0);
>> + tot += val;
>> + }
>> +
>> + return tot / LRADC_TS_SAMPLE_AMOUNT;
>> +}
>> +
>> +static void mxs_lradc_ts_work(struct work_struct *ts_work)
>> +{
>> + struct mxs_lradc *lradc = container_of(ts_work,
>> + struct mxs_lradc, ts_work);
>> + int val_x, val_y, val_p;
>> + bool valid = false;
>> +
>> + while (mxs_lradc_ts_touched(lradc)) {
>> + /* Disable touch detector so we can sample the touchscreen. */
>> + writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>> +
>> + if (likely(valid)) {
>> + input_report_abs(lradc->ts_input, ABS_X, val_x);
>> + input_report_abs(lradc->ts_input, ABS_Y, val_y);
>> + input_report_abs(lradc->ts_input, ABS_PRESSURE, val_p);
>> + input_report_key(lradc->ts_input, BTN_TOUCH, 1);
>> + input_sync(lradc->ts_input);
>> + }
>> +
>> + valid = false;
>> +
>> + val_x = mxs_lradc_ts_sample_filter(lradc, LRADC_SAMPLE_X);
>> + if (val_x < 0)
>> + continue;
>> + val_y = mxs_lradc_ts_sample_filter(lradc, LRADC_SAMPLE_Y);
>> + if (val_y < 0)
>> + continue;
>> + val_p = mxs_lradc_ts_sample_filter(lradc,
> LRADC_SAMPLE_PRESSURE);
>> + if (val_p < 0)
>> + continue;
>> +
>> + valid = true;
>> + }
>> +
>> + input_report_abs(lradc->ts_input, ABS_PRESSURE, 0);
>> + input_report_key(lradc->ts_input, BTN_TOUCH, 0);
>> + input_sync(lradc->ts_input);
>> +
>> + /* Do not restart the TS IRQ if the driver is shutting down. */
>> + if (lradc->stop_touchscreen)
>> + return;
>> +
>> + /* Restart the touchscreen interrupts. */
>> + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ,
>> + lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
>> + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
>> + lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
>> +}
>> +
>> +static int mxs_lradc_ts_open(struct input_dev *dev)
>> +{
>> + struct mxs_lradc *lradc = input_get_drvdata(dev);
>> +
>> + /* The touchscreen is starting. */
>> + lradc->stop_touchscreen = 0;
>> +
>> + /* Enable the touch-detect circuitry. */
>> + writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
>> +
>> + /* Enable the touch-detect IRQ. */
>> + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
>> + lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
>> +
>> + return 0;
>> +}
>> +
>> +static void mxs_lradc_ts_close(struct input_dev *dev)
>> +{
>> + struct mxs_lradc *lradc = input_get_drvdata(dev);
>> +
>> + /* Indicate the touchscreen is stopping. */
>> + lradc->stop_touchscreen = 1;
>> +
>> + /* Disable touchscreen touch-detect IRQ. */
>> + writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
>> + lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
>> +
>> + /* Power-down touchscreen touch-detect circuitry. */
>> + writel(LRADC_CTRL0_TOUCH_DETECT_ENABLE,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>> +
>> + /* Wait until touchscreen thread finishes any possible remnants. */
>> + cancel_work_sync(&lradc->ts_work);
>> +}
>> +
>> +static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
>> +{
>> + struct input_dev *input;
>> + struct device *dev = lradc->dev;
>> + int ret;
>> +
>> + if (!lradc->use_touchscreen)
>> + return 0;
>> +
>> + input = input_allocate_device();
>> + if (!input) {
>> + dev_warn(dev, "Failed to allocate TS device, disabling.\n");
>> + lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_NONE;
>> + return 0;
>> + }
>> +
>> + input->name = DRIVER_NAME;
>> + input->id.bustype = BUS_HOST;
>> + input->dev.parent = dev;
>> + input->open = mxs_lradc_ts_open;
>> + input->close = mxs_lradc_ts_close;
>> +
>> + __set_bit(EV_ABS, input->evbit);
>> + __set_bit(EV_KEY, input->evbit);
>> + __set_bit(BTN_TOUCH, input->keybit);
>> + input_set_abs_params(input, ABS_X, 0, LRADC_CH_VALUE_MASK, 0, 0);
>> + input_set_abs_params(input, ABS_Y, 0, LRADC_CH_VALUE_MASK, 0, 0);
>> + input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_CH_VALUE_MASK, 0, 0);
>> +
>> + lradc->ts_input = input;
>> + input_set_drvdata(input, lradc);
>> + ret = input_register_device(input);
>> + if (ret)
>> + input_free_device(lradc->ts_input);
>> +
>> + return ret;
>> +}
>> +
>> +static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
>> +{
>> + if (!lradc->use_touchscreen)
>> + return;
>> +
>> + if (!lradc->ts_input)
>> + return;
>> +
>> + cancel_work_sync(&lradc->ts_work);
>> +
>> + input_unregister_device(lradc->ts_input);
>> +}
>> +
>> +/*
>> * IRQ Handling
>> */
>> static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
>> @@ -202,14 +550,24 @@ static irqreturn_t mxs_lradc_handle_irq(int irq, void
>> *data) struct iio_dev *iio = data;
>> struct mxs_lradc *lradc = iio_priv(iio);
>> unsigned long reg = readl(lradc->base + LRADC_CTRL1);
>> + const uint32_t ts_irq_mask =
>> + LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
>> + LRADC_CTRL1_TOUCH_DETECT_IRQ;
>>
>> if (!(reg & LRADC_CTRL1_LRADC_IRQ_MASK))
>> return IRQ_NONE;
>>
>> /*
>> - * Touchscreen IRQ handling code shall probably have priority
>> - * and therefore shall be placed here.
>> + * Touchscreen IRQ handling code has priority and therefore
>> + * is placed here. In case touchscreen IRQ arrives, disable
>> + * it ASAP
>> */
>> + if (reg & LRADC_CTRL1_TOUCH_DETECT_IRQ) {
>> + writel(ts_irq_mask,
>> + lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
>> + if (!lradc->stop_touchscreen)
>> + schedule_work(&lradc->ts_work);
>> + }
>>
>> if (iio_buffer_enabled(iio))
>> iio_trigger_poll(iio->trig, iio_get_time_ns());
>> @@ -306,8 +664,10 @@ static int mxs_lradc_buffer_preenable(struct iio_dev
>> *iio) {
>> struct mxs_lradc *lradc = iio_priv(iio);
>> struct iio_buffer *buffer = iio->buffer;
>> - int ret = 0, chan, ofs = 0, enable = 0;
>> - uint32_t ctrl4 = 0;
>> + int ret = 0, chan, ofs = 0;
>> + unsigned long enable = 0;
>> + uint32_t ctrl4_set = 0;
>> + uint32_t ctrl4_clr = 0;
>> uint32_t ctrl1_irq = 0;
>> const uint32_t chan_value = LRADC_CH_ACCUMULATE |
>> ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
>> @@ -339,17 +699,20 @@ static int mxs_lradc_buffer_preenable(struct iio_dev
>> *iio) writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>>
>> for_each_set_bit(chan, buffer->scan_mask, LRADC_MAX_TOTAL_CHANS) {
>> - ctrl4 |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
>> + ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
>> + ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
>> ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
>> writel(chan_value, lradc->base + LRADC_CH(ofs));
>> - enable |= 1 << ofs;
>> + bitmap_set(&enable, ofs, 1);
>> ofs++;
>> };
>>
>> writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
>> lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);
>>
>> - writel(ctrl4, lradc->base + LRADC_CTRL4);
>> + writel(ctrl4_clr, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
>> + writel(ctrl4_set, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>> +
>> writel(ctrl1_irq, lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
>>
>> writel(enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
>> @@ -384,9 +747,33 @@ static int mxs_lradc_buffer_postdisable(struct iio_dev
>> *iio) static bool mxs_lradc_validate_scan_mask(struct iio_dev *iio,
>> const unsigned long *mask)
>> {
>> - const int mw = bitmap_weight(mask, iio->masklength);
>> -
>> - return mw <= LRADC_MAX_MAPPED_CHANS;
>> + struct mxs_lradc *lradc = iio_priv(iio);
>> + const int len = iio->masklength;
>> + const int map_chans = bitmap_weight(mask, len);
>> + int rsvd_chans = 0;
>> + unsigned long rsvd_mask = 0;
>> +
>> + if (lradc->use_touchbutton)
>> + rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
>> + if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE)
>> + rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
>> + if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
>> + rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
>> +
>> + if (lradc->use_touchbutton)
>> + rsvd_chans++;
>> + if (lradc->use_touchscreen)
>> + rsvd_chans++;
>> +
>> + /* Test for attempts to map channels with special mode of operation. */
>> + if (bitmap_intersects(mask, &rsvd_mask, len))
>> + return 0;
>> +
>> + /* Test for attempts to map more channels then available slots. */
>> + if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
>> + return 0;
>> +
>> + return 1;
>> }
>>
>> static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
>> @@ -435,15 +822,29 @@ static const struct iio_chan_spec
>> mxs_lradc_chan_spec[] = {
>>
>> static void mxs_lradc_hw_init(struct mxs_lradc *lradc)
>> {
>> - int i;
>> - const uint32_t cfg =
>> + /* The ADC always uses DELAY CHANNEL 0. */
>> + const uint32_t adc_cfg =
>> + (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
>> (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);
>>
>> stmp_reset_block(lradc->base);
>>
>> - for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
>> - writel(cfg | (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + i)),
>> - lradc->base + LRADC_DELAY(i));
>> + /* Configure DELAY CHANNEL 0 for generic ADC sampling. */
>> + writel(adc_cfg, lradc->base + LRADC_DELAY(0));
>> +
>> + /* Disable remaining DELAY CHANNELs */
>> + writel(0, lradc->base + LRADC_DELAY(1));
>> + writel(0, lradc->base + LRADC_DELAY(2));
>> + writel(0, lradc->base + LRADC_DELAY(3));
>> +
>> + /* Configure the touchscreen type */
>> + writel(LRADC_CTRL0_TOUCH_SCREEN_TYPE,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
>> +
>> + if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE) {
>> + writel(LRADC_CTRL0_TOUCH_SCREEN_TYPE,
>> + lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
>> + }
>>
>> /* Start internal temperature sensing. */
>> writel(0, lradc->base + LRADC_CTRL2);
>> @@ -463,9 +864,11 @@ static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
>> static int __devinit mxs_lradc_probe(struct platform_device *pdev)
>> {
>> struct device *dev = &pdev->dev;
>> + struct device_node *node = dev->of_node;
>> struct mxs_lradc *lradc;
>> struct iio_dev *iio;
>> struct resource *iores;
>> + uint32_t ts_wires = 0;
>> int ret = 0;
>> int i;
>>
>> @@ -487,6 +890,21 @@ static int __devinit mxs_lradc_probe(struct
>> platform_device *pdev) goto err_addr;
>> }
>>
>> + INIT_WORK(&lradc->ts_work, mxs_lradc_ts_work);
>> +
>> + /* Check if touchscreen is enabled in DT. */
>> + ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
>> + &ts_wires);
>> + if (ret)
>> + dev_info(dev, "Touchscreen not enabled.\n");
>> + else if (ts_wires == 4)
>> + lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
>> + else if (ts_wires == 5)
>> + lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
>> + else
>> + dev_warn(dev, "Unsupported number of touchscreen wires (%d)\n",
>> + ts_wires);
>> +
>> /* Grab all IRQ sources */
>> for (i = 0; i < 13; i++) {
>> lradc->irq[i] = platform_get_irq(pdev, i);
>> @@ -524,11 +942,16 @@ static int __devinit mxs_lradc_probe(struct
>> platform_device *pdev) if (ret)
>> goto err_trig;
>>
>> + /* Register the touchscreen input device. */
>> + ret = mxs_lradc_ts_register(lradc);
>> + if (ret)
>> + goto err_dev;
>> +
>> /* Register IIO device. */
>> ret = iio_device_register(iio);
>> if (ret) {
>> dev_err(dev, "Failed to register IIO device\n");
>> - goto err_dev;
>> + goto err_ts;
>> }
>>
>> /* Configure the hardware. */
>> @@ -536,6 +959,8 @@ static int __devinit mxs_lradc_probe(struct
>> platform_device *pdev)
>>
>> return 0;
>>
>> +err_ts:
>> + mxs_lradc_ts_unregister(lradc);
>> err_dev:
>> mxs_lradc_trigger_remove(iio);
>> err_trig:
>> @@ -550,6 +975,8 @@ static int __devexit mxs_lradc_remove(struct
>> platform_device *pdev) struct iio_dev *iio = platform_get_drvdata(pdev);
>> struct mxs_lradc *lradc = iio_priv(iio);
>>
>> + mxs_lradc_ts_unregister(lradc);
>> +
>> mxs_lradc_hw_stop(lradc);
>>
>> iio_device_unregister(iio);
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