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path: root/drivers/mfd/ti_am335x_tscadc.c
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Diffstat (limited to 'drivers/mfd/ti_am335x_tscadc.c')
-rw-r--r--drivers/mfd/ti_am335x_tscadc.c71
1 files changed, 60 insertions, 11 deletions
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));