lkml.org 
[lkml]   [2014]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 04/15] iio: adc: at91_adc: Add support for touchscreens without TSMR
    On 17/03/14 13:56, Alexandre Belloni wrote:
    > Old ADCs, as present on the sam9rl and the sam9g45 don't have a TSMR register
    > and the touchscreen support should be handled differently.
    >
    You cleared up my one query on this in response to the previous version.
    > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
    Acked-by: Jonathan Cameron <jic23@kernel.org>
    > ---
    > arch/arm/mach-at91/include/mach/at91_adc.h | 13 ++
    > drivers/iio/adc/at91_adc.c | 200 ++++++++++++++++++++++-------
    > include/linux/platform_data/at91_adc.h | 8 ++
    > 3 files changed, 174 insertions(+), 47 deletions(-)
    >
    > diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h
    > index c287307b9a3b..7d80396346b2 100644
    > --- a/arch/arm/mach-at91/include/mach/at91_adc.h
    > +++ b/arch/arm/mach-at91/include/mach/at91_adc.h
    > @@ -20,6 +20,9 @@
    > #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)
    > @@ -28,6 +31,7 @@
    > #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)
    > @@ -37,6 +41,12 @@
    > #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 */
    > @@ -60,6 +70,8 @@
    > #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)
    > @@ -102,6 +114,7 @@
    > #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)
    >
    > #endif
    > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
    > index 1beae65aef2c..c0e4206e34e5 100644
    > --- a/drivers/iio/adc/at91_adc.c
    > +++ b/drivers/iio/adc/at91_adc.c
    > @@ -46,6 +46,10 @@
    > #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
    > +
    > /**
    > * struct at91_adc_reg_desc - Various informations relative to registers
    > * @channel_base: Base offset for the channel data registers
    > @@ -83,12 +87,6 @@ struct at91_adc_caps {
    > struct at91_adc_reg_desc registers;
    > };
    >
    > -enum atmel_adc_ts_type {
    > - ATMEL_ADC_TOUCHSCREEN_NONE = 0,
    > - ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
    > - ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
    > -};
    > -
    > struct at91_adc_state {
    > struct clk *adc_clk;
    > u16 *buffer;
    > @@ -133,6 +131,11 @@ struct at91_adc_state {
    >
    > 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)
    > @@ -239,7 +242,72 @@ static int at91_ts_sample(struct at91_adc_state *st)
    > return 0;
    > }
    >
    > -static irqreturn_t at91_adc_interrupt(int irq, void *private)
    > +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 & st->registers->drdy_mask)
    > + 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)) {
    > + /* Conversion finished */
    > + 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);
    > @@ -672,6 +740,8 @@ static int at91_adc_probe_dt_ts(struct device_node *node,
    > 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;
    > @@ -795,6 +865,7 @@ static int at91_adc_probe_pdata(struct at91_adc_state *st,
    > 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;
    > }
    > @@ -809,7 +880,10 @@ static int atmel_ts_open(struct input_dev *dev)
    > {
    > struct at91_adc_state *st = input_get_drvdata(dev);
    >
    > - at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
    > + 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;
    > }
    >
    > @@ -817,45 +891,61 @@ static void atmel_ts_close(struct input_dev *dev)
    > {
    > struct at91_adc_state *st = input_get_drvdata(dev);
    >
    > - at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
    > + if (st->caps->has_tsmr)
    > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
    > + else
    > + at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
    > }
    >
    > static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
    > {
    > - u32 reg = 0, pendbc;
    > + u32 reg = 0;
    > int i = 0;
    >
    > - if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
    > - reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
    > - else
    > - reg = AT91_ADC_TSMR_TSMODE_5WIRE;
    > -
    > /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
    > * pen detect noise.
    > * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
    > */
    > - pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz / 1000, 1);
    > + st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
    > + 1000, 1);
    >
    > - while (pendbc >> ++i)
    > + while (st->ts_pendbc >> ++i)
    > ; /* Empty! Find the shift offset */
    > - if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1))))
    > - pendbc = i;
    > + if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
    > + st->ts_pendbc = i;
    > else
    > - pendbc = i - 1;
    > + st->ts_pendbc = i - 1;
    >
    > - if (st->caps->has_tsmr) {
    > - reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
    > - & AT91_ADC_TSMR_TSAV;
    > - reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC;
    > - reg |= AT91_ADC_TSMR_NOTSDMA;
    > - reg |= AT91_ADC_TSMR_PENDET_ENA;
    > - reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */
    > -
    > - at91_adc_writel(st, AT91_ADC_TSMR, reg);
    > - } else {
    > - /* TODO: for 9g45 which has no TSMR */
    > + if (!st->caps->has_tsmr) {
    > + reg = at91_adc_readl(st, AT91_ADC_MR);
    > + reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
    > +
    > + reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
    > + at91_adc_writel(st, AT91_ADC_MR, reg);
    > +
    > + reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
    > + at91_adc_writel(st, AT91_ADC_TSR, reg);
    > +
    > + st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
    > + adc_clk_khz / 1000) - 1, 1);
    > +
    > + return 0;
    > }
    >
    > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
    > + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
    > + else
    > + reg = AT91_ADC_TSMR_TSMODE_5WIRE;
    > +
    > + reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
    > + & AT91_ADC_TSMR_TSAV;
    > + reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
    > + reg |= AT91_ADC_TSMR_NOTSDMA;
    > + reg |= AT91_ADC_TSMR_PENDET_ENA;
    > + reg |= 0x03 << 8; /* TSFREQ, needs to be bigger than TSAV */
    > +
    > + at91_adc_writel(st, AT91_ADC_TSMR, reg);
    > +
    > /* Change adc internal resistor value for better pen detection,
    > * default value is 100 kOhm.
    > * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
    > @@ -864,7 +954,7 @@ static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
    > at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
    > & AT91_ADC_ACR_PENDETSENS);
    >
    > - /* Sample Peroid Time = (TRGPER + 1) / ADCClock */
    > + /* Sample Period Time = (TRGPER + 1) / ADCClock */
    > st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
    > adc_clk_khz / 1000) - 1, 1);
    >
    > @@ -893,17 +983,37 @@ static int at91_ts_register(struct at91_adc_state *st,
    > __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, (1 << MAX_POS_BITS) - 1, 0, 0);
    > - input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
    > - input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
    > + if (st->caps->has_tsmr) {
    > + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
    > + 0, 0);
    > + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
    > + 0, 0);
    > + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
    > + } else {
    > + if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
    > + dev_err(&pdev->dev,
    > + "This touchscreen controller only support 4 wires\n");
    > + ret = -EINVAL;
    > + goto err;
    > + }
    > +
    > + input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
    > + 0, 0);
    > + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
    > + 0, 0);
    > + }
    >
    > st->ts_input = input;
    > input_set_drvdata(input, st);
    >
    > ret = input_register_device(input);
    > if (ret)
    > - input_free_device(st->ts_input);
    > + goto err;
    > +
    > + return ret;
    >
    > +err:
    > + input_free_device(st->ts_input);
    > return ret;
    > }
    >
    > @@ -962,11 +1072,13 @@ static int at91_adc_probe(struct platform_device *pdev)
    > */
    > at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
    > at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
    > - ret = request_irq(st->irq,
    > - at91_adc_interrupt,
    > - 0,
    > - pdev->dev.driver->name,
    > - idev);
    > +
    > + if (st->caps->has_tsmr)
    > + ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
    > + pdev->dev.driver->name, idev);
    > + else
    > + ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
    > + pdev->dev.driver->name, idev);
    > if (ret) {
    > dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
    > return ret;
    > @@ -1070,12 +1182,6 @@ static int at91_adc_probe(struct platform_device *pdev)
    > goto error_disable_adc_clk;
    > }
    > } else {
    > - if (!st->caps->has_tsmr) {
    > - dev_err(&pdev->dev, "We don't support non-TSMR adc\n");
    > - ret = -ENODEV;
    > - goto error_disable_adc_clk;
    > - }
    > -
    > ret = at91_ts_register(st, pdev);
    > if (ret)
    > goto error_disable_adc_clk;
    > diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
    > index fcf73879dbfe..7819fc787731 100644
    > --- a/include/linux/platform_data/at91_adc.h
    > +++ b/include/linux/platform_data/at91_adc.h
    > @@ -7,6 +7,12 @@
    > #ifndef _AT91_ADC_H_
    > #define _AT91_ADC_H_
    >
    > +enum atmel_adc_ts_type {
    > + ATMEL_ADC_TOUCHSCREEN_NONE = 0,
    > + ATMEL_ADC_TOUCHSCREEN_4WIRE = 4,
    > + ATMEL_ADC_TOUCHSCREEN_5WIRE = 5,
    > +};
    > +
    > /**
    > * struct at91_adc_trigger - description of triggers
    > * @name: name of the trigger advertised to the user
    > @@ -28,6 +34,7 @@ struct at91_adc_trigger {
    > * @trigger_number: Number of triggers available in the ADC
    > * @use_external_triggers: does the board has external triggers availables
    > * @vref: Reference voltage for the ADC in millivolts
    > + * @touchscreen_type: If a touchscreen is connected, its type (4 or 5 wires)
    > */
    > struct at91_adc_data {
    > unsigned long channels_used;
    > @@ -36,6 +43,7 @@ struct at91_adc_data {
    > u8 trigger_number;
    > bool use_external_triggers;
    > u16 vref;
    > + enum atmel_adc_ts_type touchscreen_type;
    > };
    >
    > extern void __init at91_add_device_adc(struct at91_adc_data *data);
    >



    \
     
     \ /
      Last update: 2014-03-22 14:21    [W:4.593 / U:0.764 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site