mfd: add set_ts_bits for pcap

Some TS controller bits are on the same register as the ADC control, save
TS specific bits and export a set_ts_bits function so the TS driver can set
it with the adc_mutex lock held.
Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/ezx-pcap.c

@@ -195,6 +195,19 @@ static void pcap_irq_handler(unsigned int irq, struct irq_desc *desc)
 }
 
 /* ADC */
+void pcap_set_ts_bits(struct pcap_chip *pcap, u32 bits)
+{
+	u32 tmp;
+
+	mutex_lock(&pcap->adc_mutex);
+	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
+	tmp &= ~(PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
+	tmp |= bits & (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
+	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
+	mutex_unlock(&pcap->adc_mutex);
+}
+EXPORT_SYMBOL_GPL(pcap_set_ts_bits);
+
 static void pcap_disable_adc(struct pcap_chip *pcap)
 {
 	u32 tmp;
@@ -217,15 +230,16 @@ static void pcap_adc_trigger(struct pcap_chip *pcap)
 		mutex_unlock(&pcap->adc_mutex);
 		return;
 	}
-	mutex_unlock(&pcap->adc_mutex);
-
-	/* start conversion on requested bank */
-	tmp = pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
+	/* start conversion on requested bank, save TS_M bits */
+	ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
+	tmp &= (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
+	tmp |= pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
 
 	if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
 		tmp |= PCAP_ADC_AD_SEL1;
 
 	ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
+	mutex_unlock(&pcap->adc_mutex);
 	ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
 }
 

include/linux/mfd/ezx-pcap.h

@@ -29,6 +29,7 @@ int pcap_to_irq(struct pcap_chip *, int);
 int irq_to_pcap(struct pcap_chip *, int);
 int pcap_adc_async(struct pcap_chip *, u8, u32, u8[], void *, void *);
 int pcap_adc_sync(struct pcap_chip *, u8, u32, u8[], u16[]);
+void pcap_set_ts_bits(struct pcap_chip *, u32);
 
 #define PCAP_SECOND_PORT	1
 #define PCAP_CS_AH		2