| Message ID | 20230120124544.5993-3-l.ellero@asem.it (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Input: ads7846 - fix support for ADS7845 | expand |
On Fri, Jan 20, 2023 at 01:45:43PM +0100, Luca Ellero wrote: > Controllers that report pressure (e.g. ADS7846) use 5 commands and the > correct sequence is READ_X, READ_Y, READ_Z1, READ_Z2, PWRDOWN. > > Controllers that don't report pressure (e.g. ADS7845/ADS7843) use only 3 > commands and the correct sequence should be READ_X, READ_Y, PWRDOWN. But > the sequence sent was incorrect: READ_X, READ_Y, READ_Z1. > > Fix this by setting the third (and last) command to PWRDOWN. Provide a Fixes: tag? > Signed-off-by: Luca Ellero <l.ellero@asem.it>
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index f11b444f2138..15da1047a577 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -1066,6 +1066,9 @@ static int ads7846_setup_spi_msg(struct ads7846 *ts, struct ads7846_buf_layout *l = &packet->l[cmd_idx]; unsigned int max_count; + if (cmd_idx == packet->cmds - 1) + cmd_idx = ADS7846_PWDOWN; + if (ads7846_cmd_need_settle(cmd_idx)) max_count = packet->count + packet->count_skip; else @@ -1102,7 +1105,12 @@ static int ads7846_setup_spi_msg(struct ads7846 *ts, for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) { struct ads7846_buf_layout *l = &packet->l[cmd_idx]; - u8 cmd = ads7846_get_cmd(cmd_idx, vref); + u8 cmd; + + if (cmd_idx == packet->cmds - 1) + cmd_idx = ADS7846_PWDOWN; + + cmd = ads7846_get_cmd(cmd_idx, vref); for (b = 0; b < l->count; b++) packet->tx[l->offset + b].cmd = cmd;
Controllers that report pressure (e.g. ADS7846) use 5 commands and the correct sequence is READ_X, READ_Y, READ_Z1, READ_Z2, PWRDOWN. Controllers that don't report pressure (e.g. ADS7845/ADS7843) use only 3 commands and the correct sequence should be READ_X, READ_Y, PWRDOWN. But the sequence sent was incorrect: READ_X, READ_Y, READ_Z1. Fix this by setting the third (and last) command to PWRDOWN. Signed-off-by: Luca Ellero <l.ellero@asem.it> --- drivers/input/touchscreen/ads7846.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)