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-rw-r--r--drivers/iio/adc/ti_am335x_adc.c68
-rw-r--r--drivers/input/touchscreen/ti_am335x_tsc.c4
-rw-r--r--drivers/mfd/ti_am335x_tscadc.c71
-rw-r--r--include/linux/mfd/ti_am335x_tscadc.h8
4 files changed, 117 insertions, 34 deletions
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index d4d748214e4b..31e786e3999b 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/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;
}
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 68beadaabceb..2ca5a7bee04e 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/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;
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 88718abfb9ba..d4e860413bb5 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/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));
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index d498d98f0c2c..fb96c84dada5 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/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