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authorVignesh R <vigneshr@ti.com>2015-01-07 11:19:36 +0530
committerLee Jones <lee.jones@linaro.org>2015-03-03 16:41:15 +0000
commitb10848e6f9fa7638fc0713695a12c0735ffb52b7 (patch)
treec0f5aa5420e3a843d8e0dcd4b1a62a1ab8e8f331
parentf0bd7ccc413f6de0947d6b8e998ef1fb787513ff (diff)
downloadblackbird-op-linux-b10848e6f9fa7638fc0713695a12c0735ffb52b7.tar.gz
blackbird-op-linux-b10848e6f9fa7638fc0713695a12c0735ffb52b7.zip
mfd: ti_am335x_tscadc: Remove unwanted reg_se_cache save
In one shot mode, sequencer automatically disables all enabled steps at the end of each cycle. (both ADC steps and TSC steps) Hence these steps need not be saved in reg_se_cache for clearing these steps at a later stage. Also, when ADC wakes up Sequencer should not be busy executing any of the config steps except for the charge step. Previously charge step was 1 ADC clock cycle and hence it was ignored. TSC steps are always disabled at the end of each conversion cycle, hence there is no need to explicitly disable TSC steps by writing 0 to REG_SE. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
-rw-r--r--drivers/mfd/ti_am335x_tscadc.c13
-rw-r--r--include/linux/mfd/ti_am335x_tscadc.h1
2 files changed, 6 insertions, 8 deletions
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 467c80e1c4ae..e4e4b22eebc9 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -68,12 +68,6 @@ 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;
@@ -86,8 +80,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
spin_lock_irq(&tsadc->reg_lock);
finish_wait(&tsadc->reg_se_wait, &wait);
+ /*
+ * Sequencer should either be idle or
+ * busy applying the charge step.
+ */
reg = tscadc_readl(tsadc, REG_ADCFSM);
- WARN_ON(reg & SEQ_STATUS);
+ WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
tsadc->adc_waiting = false;
}
tsadc->adc_in_use = true;
@@ -96,7 +94,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
{
spin_lock_irq(&tsadc->reg_lock);
- tsadc->reg_se_cache |= val;
am335x_tscadc_need_adc(tsadc);
tscadc_writel(tsadc, REG_SE, val);
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 3f4e994ace2b..1fd50dcfe47c 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -128,6 +128,7 @@
/* Sequencer Status */
#define SEQ_STATUS BIT(5)
+#define CHARGE_STEP 0x11
#define ADC_CLK 3000000
#define TOTAL_STEPS 16
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