Merge tag 'ib-iio-input-3.13-1' into for-mfd-next

Immutable branch for IIO and Input

drivers/iio/adc/ti_am335x_adc.c

@@ -60,6 +60,24 @@ static u32 get_adc_step_mask(struct tiadc_device *adc_dev)
 	return step_en;
 }
 
+static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev,
+		struct iio_chan_spec const *chan)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) {
+		if (chan->channel == adc_dev->channel_line[i]) {
+			u32 step;
+
+			step = adc_dev->channel_step[i];
+			/* +1 for the charger */
+			return 1 << (step + 1);
+		}
+	}
+	WARN_ON(1);
+	return 0;
+}
+
 static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan)
 {
 	return 1 << adc_dev->channel_step[chan];
@@ -181,7 +199,7 @@ static int tiadc_buffer_postenable(struct iio_dev *indio_dev)
 		enb |= (get_adc_step_bit(adc_dev, bit) << 1);
 	adc_dev->buffer_en_ch_steps = enb;
 
-	am335x_tsc_se_set(adc_dev->mfd_tscadc, enb);
+	am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb);
 
 	tiadc_writel(adc_dev,  REG_IRQSTATUS, IRQENB_FIFO1THRES
 				| IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW);
@@ -199,6 +217,7 @@ static int tiadc_buffer_predisable(struct iio_dev *indio_dev)
 	tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
 				IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW));
 	am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps);
+	adc_dev->buffer_en_ch_steps = 0;
 
 	/* Flush FIFO of leftover data in the time it takes to disable adc */
 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
@@ -328,34 +347,43 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 	unsigned int fifo1count, read, stepid;
 	bool found = false;
 	u32 step_en;
-	unsigned long timeout = jiffies + usecs_to_jiffies
-				(IDLE_TIMEOUT * adc_dev->channels);
+	unsigned long timeout;
 
 	if (iio_buffer_enabled(indio_dev))
 		return -EBUSY;
 
-	step_en = get_adc_step_mask(adc_dev);
-	am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en);
+	step_en = get_adc_chan_step_mask(adc_dev, chan);
+	if (!step_en)
+		return -EINVAL;
+
+	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+	while (fifo1count--)
+		tiadc_readl(adc_dev, REG_FIFO1);
+
+	am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
 
-	/* Wait for ADC sequencer to complete sampling */
-	while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) {
-		if (time_after(jiffies, timeout))
+	timeout = jiffies + usecs_to_jiffies
+				(IDLE_TIMEOUT * adc_dev->channels);
+	/* Wait for Fifo threshold interrupt */
+	while (1) {
+		fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+		if (fifo1count)
+			break;
+
+		if (time_after(jiffies, timeout)) {
+			am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
 			return -EAGAIN;
 		}
+	}
 	map_val = chan->channel + TOTAL_CHANNELS;
 
 	/*
-	 * When the sub-system is first enabled,
-	 * the sequencer will always start with the
-	 * lowest step (1) and continue until step (16).
-	 * For ex: If we have enabled 4 ADC channels and
-	 * currently use only 1 out of them, the
-	 * sequencer still configures all the 4 steps,
-	 * leading to 3 unwanted data.
-	 * Hence we need to flush out this data.
+	 * We check the complete FIFO. We programmed just one entry but in case
+	 * something went wrong we left empty handed (-EAGAIN previously) and
+	 * then the value apeared somehow in the FIFO we would have two entries.
+	 * Therefore we read every item and keep only the latest version of the
+	 * requested channel.
 	 */
-
-	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 	for (i = 0; i < fifo1count; i++) {
 		read = tiadc_readl(adc_dev, REG_FIFO1);
 		stepid = read & FIFOREAD_CHNLID_MASK;
@@ -367,6 +395,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 			*val = (u16) read;
 		}
 	}
+	am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
 
 	if (found == false)
 		return -EBUSY;
@@ -494,7 +523,8 @@ static int tiadc_resume(struct device *dev)
 	tiadc_writel(adc_dev, REG_CTRL, restore);
 
 	tiadc_step_config(indio_dev);
-
+	am335x_tsc_se_set_cache(adc_dev->mfd_tscadc,
+			adc_dev->buffer_en_ch_steps);
 	return 0;
 }
 

drivers/input/touchscreen/ti_am335x_tsc.c

@@ -198,7 +198,7 @@ static void titsc_step_config(struct titsc *ts_dev)
 	/* The steps1 … end and bit 0 for TS_Charge */
 	stepenable = (1 << (end_step + 2)) - 1;
 	ts_dev->step_mask = stepenable;
-	am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask);
+	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
 }
 
 static void titsc_read_coordinates(struct titsc *ts_dev,
@@ -322,7 +322,7 @@ static irqreturn_t titsc_irq(int irq, void *dev)
 
 	if (irqclr) {
 		titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
-		am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask);
+		am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
 		return IRQ_HANDLED;
 	}
 	return IRQ_NONE;

drivers/mfd/ti_am335x_tscadc.c

@@ -24,6 +24,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/sched.h>
 
 #include <linux/mfd/ti_am335x_tscadc.h>
 
@@ -48,32 +49,79 @@ static const struct regmap_config tscadc_regmap_config = {
 	.val_bits = 32,
 };
 
-void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc)
+void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val)
 {
-	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
+	unsigned long flags;
+
+	spin_lock_irqsave(&tsadc->reg_lock, flags);
+	tsadc->reg_se_cache = val;
+	if (tsadc->adc_waiting)
+		wake_up(&tsadc->reg_se_wait);
+	else if (!tsadc->adc_in_use)
+		tscadc_writel(tsadc, REG_SE, val);
+
+	spin_unlock_irqrestore(&tsadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
+
+static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
+{
+	DEFINE_WAIT(wait);
+	u32 reg;
+
+	/*
+	 * disable TSC steps so it does not run while the ADC is using it. If
+	 * write 0 while it is running (it just started or was already running)
+	 * then it completes all steps that were enabled and stops then.
+	 */
+	tscadc_writel(tsadc, REG_SE, 0);
+	reg = tscadc_readl(tsadc, REG_ADCFSM);
+	if (reg & SEQ_STATUS) {
+		tsadc->adc_waiting = true;
+		prepare_to_wait(&tsadc->reg_se_wait, &wait,
+				TASK_UNINTERRUPTIBLE);
+		spin_unlock_irq(&tsadc->reg_lock);
+
+		schedule();
+
+		spin_lock_irq(&tsadc->reg_lock);
+		finish_wait(&tsadc->reg_se_wait, &wait);
+
+		reg = tscadc_readl(tsadc, REG_ADCFSM);
+		WARN_ON(reg & SEQ_STATUS);
+		tsadc->adc_waiting = false;
+	}
+	tsadc->adc_in_use = true;
+}
+
+void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
+{
+	spin_lock_irq(&tsadc->reg_lock);
+	am335x_tscadc_need_adc(tsadc);
+
+	tscadc_writel(tsadc, REG_SE, val);
+	spin_unlock_irq(&tsadc->reg_lock);
 }
-EXPORT_SYMBOL_GPL(am335x_tsc_se_update);
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
 
-void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val)
+void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&tsadc->reg_lock, flags);
-	tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE);
-	tsadc->reg_se_cache |= val;
-	am335x_tsc_se_update(tsadc);
+	tsadc->adc_in_use = false;
+	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
 	spin_unlock_irqrestore(&tsadc->reg_lock, flags);
 }
-EXPORT_SYMBOL_GPL(am335x_tsc_se_set);
+EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
 
 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&tsadc->reg_lock, flags);
-	tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE);
 	tsadc->reg_se_cache &= ~val;
-	am335x_tsc_se_update(tsadc);
+	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
 	spin_unlock_irqrestore(&tsadc->reg_lock, flags);
 }
 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
@@ -181,6 +229,8 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 	}
 
 	spin_lock_init(&tscadc->reg_lock);
+	init_waitqueue_head(&tscadc->reg_se_wait);
+
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);
 
@@ -302,7 +352,6 @@ static int tscadc_resume(struct device *dev)
 
 	if (tscadc_dev->tsc_cell != -1)
 		tscadc_idle_config(tscadc_dev);
-	am335x_tsc_se_update(tscadc_dev);
 	restore = tscadc_readl(tscadc_dev, REG_CTRL);
 	tscadc_writel(tscadc_dev, REG_CTRL,
 			(restore | CNTRLREG_TSCSSENB));

include/linux/mfd/ti_am335x_tscadc.h

@@ -159,6 +159,9 @@ struct ti_tscadc_dev {
 	int adc_cell;	/* -1 if not used */
 	struct mfd_cell cells[TSCADC_CELLS];
 	u32 reg_se_cache;
+	bool adc_waiting;
+	bool adc_in_use;
+	wait_queue_head_t reg_se_wait;
 	spinlock_t reg_lock;
 	unsigned int clk_div;
 
@@ -176,8 +179,9 @@ static inline struct ti_tscadc_dev *ti_tscadc_dev_get(struct platform_device *p)
 	return *tscadc_dev;
 }
 
-void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc);
-void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val);
+void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val);
+void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val);
 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val);
+void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc);
 
 #endif