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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 | |
| parent | e70bdd41bd0ead91b4a43e9d656ac1569d7c8779 (diff) | |
| download | kernel_samsung_crespo-ebcaaad9d5e8fd284b8dcf25a24999420f0f56d8.zip kernel_samsung_crespo-ebcaaad9d5e8fd284b8dcf25a24999420f0f56d8.tar.gz kernel_samsung_crespo-ebcaaad9d5e8fd284b8dcf25a24999420f0f56d8.tar.bz2 | |
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>
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 19 | ||||
| -rw-r--r-- | include/linux/spi/ads7846.h | 3 |
2 files changed, 13 insertions, 9 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index c24946f..e4ee43e 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) diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h index 92bd083..c64de9d 100644 --- a/include/linux/spi/ads7846.h +++ b/include/linux/spi/ads7846.h @@ -14,7 +14,8 @@ enum ads7846_filter { struct ads7846_platform_data { u16 model; /* 7843, 7845, 7846, 7873. */ u16 vref_delay_usecs; /* 0 for external vref; etc */ - u16 vref_mv; /* external vref value, milliVolts */ + u16 vref_mv; /* external vref value, milliVolts + * ads7846: if 0, use internal vref */ bool keep_vref_on; /* set to keep vref on for differential * measurements as well */ bool swap_xy; /* swap x and y axes */ |