|
@@ -145,15 +145,16 @@ struct ads7846 {
|
|
|
#define MAX_12BIT ((1<<12)-1)
|
|
|
|
|
|
/* leave ADC powered up (disables penirq) between differential samples */
|
|
|
-#define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
|
|
|
- | ADS_12_BIT | ADS_DFR)
|
|
|
+#define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
|
|
|
+ | ADS_12_BIT | ADS_DFR | \
|
|
|
+ (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
|
|
|
|
|
|
-#define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON)
|
|
|
-#define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON)
|
|
|
-#define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON)
|
|
|
+#define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
|
|
|
+#define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
|
|
|
+#define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
|
|
|
|
|
|
-#define READ_X (READ_12BIT_DFR(x) | ADS_PD10_ADC_ON)
|
|
|
-#define PWRDOWN (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) /* LAST */
|
|
|
+#define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
|
|
|
+#define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
|
|
|
|
|
|
/* single-ended samples need to first power up reference voltage;
|
|
|
* we leave both ADC and VREF powered
|
|
@@ -161,8 +162,8 @@ struct ads7846 {
|
|
|
#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
|
|
|
| ADS_12_BIT | ADS_SER)
|
|
|
|
|
|
-#define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON)
|
|
|
-#define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN)
|
|
|
+#define REF_ON (READ_12BIT_DFR(x, 1, 1))
|
|
|
+#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
|
|
|
|
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
|
@@ -670,6 +671,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|
|
struct ads7846_platform_data *pdata = spi->dev.platform_data;
|
|
|
struct spi_message *m;
|
|
|
struct spi_transfer *x;
|
|
|
+ int vref;
|
|
|
int err;
|
|
|
|
|
|
if (!spi->irq) {
|
|
@@ -767,6 +769,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|
|
input_set_abs_params(input_dev, ABS_PRESSURE,
|
|
|
pdata->pressure_min, pdata->pressure_max, 0, 0);
|
|
|
|
|
|
+ vref = pdata->keep_vref_on;
|
|
|
+
|
|
|
/* set up the transfers to read touchscreen state; this assumes we
|
|
|
* use formula #2 for pressure, not #3.
|
|
|
*/
|
|
@@ -776,7 +780,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|
|
spi_message_init(m);
|
|
|
|
|
|
/* y- still on; turn on only y+ (and ADC) */
|
|
|
- ts->read_y = READ_Y;
|
|
|
+ ts->read_y = READ_Y(vref);
|
|
|
x->tx_buf = &ts->read_y;
|
|
|
x->len = 1;
|
|
|
spi_message_add_tail(x, m);
|
|
@@ -794,7 +798,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|
|
|
|
|
/* turn y- off, x+ on, then leave in lowpower */
|
|
|
x++;
|
|
|
- ts->read_x = READ_X;
|
|
|
+ ts->read_x = READ_X(vref);
|
|
|
x->tx_buf = &ts->read_x;
|
|
|
x->len = 1;
|
|
|
spi_message_add_tail(x, m);
|
|
@@ -813,7 +817,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|
|
spi_message_init(m);
|
|
|
|
|
|
x++;
|
|
|
- ts->read_z1 = READ_Z1;
|
|
|
+ ts->read_z1 = READ_Z1(vref);
|
|
|
x->tx_buf = &ts->read_z1;
|
|
|
x->len = 1;
|
|
|
spi_message_add_tail(x, m);
|
|
@@ -830,7 +834,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|
|
spi_message_init(m);
|
|
|
|
|
|
x++;
|
|
|
- ts->read_z2 = READ_Z2;
|
|
|
+ ts->read_z2 = READ_Z2(vref);
|
|
|
x->tx_buf = &ts->read_z2;
|
|
|
x->len = 1;
|
|
|
spi_message_add_tail(x, m);
|