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| author |   Alexander Stein <alexander.stein@systec-electronic.com> | 2011-05-11 16:24:08 -0700 |
|---|---|---|
| committer |   Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-05-12 08:28:56 -0700 |
| commit | ebcaaad9d5e8fd284b8dcf25a24999420f0f56d8 (patch) | |
| tree | 041e210499460d21c7acb75ced6b819f88bb4749 /drivers/input/touchscreen/ads7846.c | |
| parent | Input: rotary-encoder - add support for half-period encoders (diff) | |
| download | linux-dev-ebcaaad9d5e8fd284b8dcf25a24999420f0f56d8.tar.xz linux-dev-ebcaaad9d5e8fd284b8dcf25a24999420f0f56d8.zip | |
Input: ads7846 - add possibility to use external vref on ads7846
Just set vref_mv in your platform config to use external vref. Otherwise
the internal one is used.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/touchscreen/ads7846.c')
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index c24946f51256..e4ee43e159d2 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -109,6 +109,7 @@ struct ads7846 { u16 pressure_max; bool swap_xy; + bool use_internal; struct ads7846_packet *packet; @@ -300,7 +301,6 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) struct ads7846 *ts = dev_get_drvdata(dev); struct ser_req *req; int status; - int use_internal; req = kzalloc(sizeof *req, GFP_KERNEL); if (!req) @@ -308,11 +308,8 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) spi_message_init(&req->msg); - /* FIXME boards with ads7846 might use external vref instead ... */ - use_internal = (ts->model == 7846); - /* maybe turn on internal vREF, and let it settle */ - if (use_internal) { + if (ts->use_internal) { req->ref_on = REF_ON; req->xfer[0].tx_buf = &req->ref_on; req->xfer[0].len = 1; @@ -324,8 +321,14 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) /* for 1uF, settle for 800 usec; no cap, 100 usec. */ req->xfer[1].delay_usecs = ts->vref_delay_usecs; spi_message_add_tail(&req->xfer[1], &req->msg); + + /* Enable reference voltage */ + command |= ADS_PD10_REF_ON; } + /* Enable ADC in every case */ + command |= ADS_PD10_ADC_ON; + /* take sample */ req->command = (u8) command; req->xfer[2].tx_buf = &req->command; @@ -409,7 +412,7 @@ name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \ { \ struct ads7846 *ts = dev_get_drvdata(dev); \ ssize_t v = ads7846_read12_ser(dev, \ - READ_12BIT_SER(var) | ADS_PD10_ALL_ON); \ + READ_12BIT_SER(var)); \ if (v < 0) \ return v; \ return sprintf(buf, "%u\n", adjust(ts, v)); \ @@ -502,6 +505,7 @@ static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts) if (!ts->vref_mv) { dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); ts->vref_mv = 2500; + ts->use_internal = true; } break; case 7845: @@ -1333,8 +1337,7 @@ static int __devinit ads7846_probe(struct spi_device *spi) if (ts->model == 7845) ads7845_read12_ser(&spi->dev, PWRDOWN); else - (void) ads7846_read12_ser(&spi->dev, - READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON); + (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group); if (err) |