Firstly, changed the IRQ mode to PENDAV, which acts as a heartbeat to keep at least part of the IRQ/SPI sequence active while the pen is down. Secondly, implemented an IRQ counting scheme so that the SPI can lag far behind the IRQs. This requires ignoring pen-up timeouts until you know there are no SPI requests pending. For additional stability, lengthen the pen-up timeout, and decrease the rate of the interrupts (increase batch delay).
Signed-off-by: Phil Carmody <[email protected]> --- drivers/input/touchscreen/tsc2005.c | 56 ++++++++++++++++++++++------------ 1 files changed, 36 insertions(+), 20 deletions(-) diff --git a/drivers/input/touchscreen/tsc2005.c b/drivers/input/touchscreen/tsc2005.c index e3e63a5..104ead2 100644 --- a/drivers/input/touchscreen/tsc2005.c +++ b/drivers/input/touchscreen/tsc2005.c @@ -145,7 +145,7 @@ #define TSC2005_CFR1_BATCHDELAY_40MS (0x0006) #define TSC2005_CFR1_BATCHDELAY_100MS (0x0007) -#define TSC2005_CFR1_INITVALUE (TSC2005_CFR1_BATCHDELAY_2MS) +#define TSC2005_CFR1_INITVALUE (TSC2005_CFR1_BATCHDELAY_4MS) #define TSC2005_CFR2_MAVE_TEMP (0x0001) #define TSC2005_CFR2_MAVE_AUX (0x0002) @@ -160,11 +160,12 @@ #define TSC2005_CFR2_MEDIUM_7 (0x2000) #define TSC2005_CFR2_MEDIUM_15 (0x3000) +#define TSC2005_CFR2_IRQ_MASK (0xC000) #define TSC2005_CFR2_IRQ_DAV (0x4000) #define TSC2005_CFR2_IRQ_PEN (0x8000) #define TSC2005_CFR2_IRQ_PENDAV (0x0000) -#define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_IRQ_DAV | \ +#define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_IRQ_PENDAV | \ TSC2005_CFR2_MAVE_X | \ TSC2005_CFR2_MAVE_Y | \ TSC2005_CFR2_MAVE_Z | \ @@ -174,7 +175,7 @@ #define MAX_12BIT ((1 << 12) - 1) #define TS_SAMPLES 4 #define TS_RECT_SIZE 8 -#define TSC2005_TS_PENUP_TIME 20 +#define TSC2005_TS_PENUP_TIME 40 static const u32 tsc2005_read_reg[] = { (TSC2005_REG | TSC2005_REG_X | TSC2005_REG_READ) << 16, @@ -218,7 +219,7 @@ struct tsc2005 { u8 pen_down; u8 disabled; u8 disable_depth; - u8 spi_active; + u8 spi_pending; }; static void tsc2005_cmd(struct tsc2005 *ts, u8 cmd) @@ -327,8 +328,8 @@ static void tsc2005_ts_rx(void *arg) ts->avg_z1 = 0; ts->avg_z2 = 0; - pressure = x * (z2 - z1) / z1; - pressure = pressure * ts->x_plate_ohm / 4096; + pressure = x * (z2 - z1) / z1; + pressure = pressure * ts->x_plate_ohm / 4096; pressure_limit = ts->sample_sent? ts->p_max: ts->touch_pressure; if (pressure > pressure_limit) @@ -352,7 +353,19 @@ static void tsc2005_ts_rx(void *arg) ts->p = pressure; } out: - ts->spi_active = 0; + if (ts->spi_pending > 1) { + /* One or more interrupts (sometimes several dozens) + * occured while waiting for the SPI read - get + * another read going. + */ + ts->spi_pending = 1; + if (spi_async(ts->spi, &ts->read_msg)) { + dev_err(&ts->spi->dev, "ts: spi_async() failed"); + ts->spi_pending = 0; + } + } else + ts->spi_pending = 0; + spin_unlock_irqrestore(&ts->lock, flags); /* kick pen up timer - to make sure it expires again(!) */ @@ -364,8 +377,7 @@ out: static void tsc2005_ts_penup_timer_handler(unsigned long data) { struct tsc2005 *ts = (struct tsc2005 *)data; - - if (ts->sample_sent) { + if (!ts->spi_pending && ts->sample_sent) { tsc2005_ts_update_pen_state(ts, 0, 0, 0); ts->sample_sent = 0; } @@ -373,20 +385,21 @@ static void tsc2005_ts_penup_timer_handler(unsigned long data) /* * This interrupt is called when pen is down and coordinates are - * available. That is indicated by a falling edge on DAV line. + * available. That is indicated by a either: + * a) a rising edge on PINTDAV or (PENDAV mode) + * b) a falling edge on DAV line (DAV mode) + * depending on the setting of the IRQ bits in the CFR2 setting above. */ static irqreturn_t tsc2005_ts_irq_handler(int irq, void *dev_id) { struct tsc2005 *ts = dev_id; - int r; - - if (ts->spi_active) - return IRQ_HANDLED; - ts->spi_active = 1; - r = spi_async(ts->spi, &ts->read_msg); - if (r) - dev_err(&ts->spi->dev, "ts: spi_async() failed"); + if (!ts->spi_pending) { + if (spi_async(ts->spi, &ts->read_msg)) + dev_err(&ts->spi->dev, "ts: spi_async() failed"); + } + /* By shifting in 1s we can never wrap */ + ts->spi_pending = (ts->spi_pending<<1)+1; /* kick pen up timer */ mod_timer(&ts->penup_timer, @@ -561,8 +574,11 @@ static int __devinit tsc2005_ts_init(struct tsc2005 *ts, tsc2005_start_scan(ts); r = request_irq(ts->spi->irq, tsc2005_ts_irq_handler, - IRQF_TRIGGER_FALLING | IRQF_DISABLED | - IRQF_SAMPLE_RANDOM, "tsc2005", ts); + (((TSC2005_CFR2_INITVALUE & TSC2005_CFR2_IRQ_MASK) == + TSC2005_CFR2_IRQ_PENDAV) + ? IRQF_TRIGGER_RISING + : IRQF_TRIGGER_FALLING) | + IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "tsc2005", ts); if (r < 0) { dev_err(&ts->spi->dev, "unable to get DAV IRQ"); goto err2; -- 1.5.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
