diff options
| author | Michael Hennerich <michael.hennerich@analog.com> | 2010-10-15 09:48:10 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2010-10-17 21:12:11 -0700 |
| commit | e92c27fb5319d8b12f0c291c827e252f0e17afc4 (patch) | |
| tree | c01bf3f9bfe9b2dee980e2848987ab4b494ceda9 /drivers/input | |
| parent | 790d5c8dac35cf10cf6c52cc9b90ad20603ac2c1 (diff) | |
Input: ad7877 - implement specified chip select behavior
According to the AD7877 datasheet:
Each transfer operation is 16-bit. If multiple read/write operations are
to be performed, CS must be taken high after the end of each read/write
operation before another read/write operation can be performed by
taking CS low again.
Make sure CS toggles after each transfer in the message.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/touchscreen/ad7877.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c index 5f0221cffef..53f4d79ee53 100644 --- a/drivers/input/touchscreen/ad7877.c +++ b/drivers/input/touchscreen/ad7877.c @@ -230,6 +230,7 @@ static int ad7877_read(struct spi_device *spi, u16 reg) AD7877_READADD(reg)); req->xfer[0].tx_buf = &req->command; req->xfer[0].len = 2; + req->xfer[0].cs_change = 1; req->xfer[1].rx_buf = &req->sample; req->xfer[1].len = 2; @@ -295,20 +296,25 @@ static int ad7877_read_adc(struct spi_device *spi, unsigned command) req->xfer[0].tx_buf = &req->reset; req->xfer[0].len = 2; + req->xfer[0].cs_change = 1; req->xfer[1].tx_buf = &req->ref_on; req->xfer[1].len = 2; req->xfer[1].delay_usecs = ts->vref_delay_usecs; + req->xfer[1].cs_change = 1; req->xfer[2].tx_buf = &req->command; req->xfer[2].len = 2; req->xfer[2].delay_usecs = ts->vref_delay_usecs; + req->xfer[2].cs_change = 1; req->xfer[3].rx_buf = &req->sample; req->xfer[3].len = 2; + req->xfer[3].cs_change = 1; req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/ req->xfer[4].len = 2; + req->xfer[4].cs_change = 1; req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/ req->xfer[5].len = 2; @@ -640,17 +646,21 @@ static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts) ts->xfer[0].tx_buf = &ts->cmd_crtl1; ts->xfer[0].len = 2; + ts->xfer[0].cs_change = 1; spi_message_add_tail(&ts->xfer[0], m); ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */ ts->xfer[1].len = 2; + ts->xfer[1].cs_change = 1; spi_message_add_tail(&ts->xfer[1], m); - for (i = 0; i < 11; i++) { + for (i = 0; i < AD7877_NR_SENSE; i++) { ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i]; ts->xfer[i + 2].len = 2; + if (i < (AD7877_NR_SENSE - 1)) + ts->xfer[i + 2].cs_change = 1; spi_message_add_tail(&ts->xfer[i + 2], m); } } |