Input: iqs7222 - explicitly define number of external channels

commit 63f4970 upstream.

The number of external channels is assumed to be a multiple of 10,
but this is not the case for IQS7222D. As a result, some CRx pins
are wrongly prevented from being assigned to some channels.

Address this problem by explicitly defining the number of external
channels for cases in which the number of external channels is not
equal to the total number of available channels.

Fixes: dd24e20 ("Input: iqs7222 - add support for Azoteq IQS7222D")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/aGHVf6HkyFZrzTPy@nixie71
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jlabundy

drivers/input/misc/iqs7222.c

@@ -301,6 +301,7 @@ struct iqs7222_dev_desc {
 	int allow_offset;
 	int event_offset;
 	int comms_offset;
+	int ext_chan;
 	bool legacy_gesture;
 	struct iqs7222_reg_grp_desc reg_grps[IQS7222_NUM_REG_GRPS];
 };
@@ -315,6 +316,7 @@ static const struct iqs7222_dev_desc iqs7222_devs[] = {
 		.allow_offset = 9,
 		.event_offset = 10,
 		.comms_offset = 12,
+		.ext_chan = 10,
 		.reg_grps = {
 			[IQS7222_REG_GRP_STAT] = {
 				.base = IQS7222_SYS_STATUS,
@@ -373,6 +375,7 @@ static const struct iqs7222_dev_desc iqs7222_devs[] = {
 		.allow_offset = 9,
 		.event_offset = 10,
 		.comms_offset = 12,
+		.ext_chan = 10,
 		.legacy_gesture = true,
 		.reg_grps = {
 			[IQS7222_REG_GRP_STAT] = {
@@ -2244,7 +2247,7 @@ static int iqs7222_parse_chan(struct iqs7222_private *iqs7222,
 	const struct iqs7222_dev_desc *dev_desc = iqs7222->dev_desc;
 	struct i2c_client *client = iqs7222->client;
 	int num_chan = dev_desc->reg_grps[IQS7222_REG_GRP_CHAN].num_row;
-	int ext_chan = rounddown(num_chan, 10);
+	int ext_chan = dev_desc->ext_chan ? : num_chan;
 	int error, i;
 	u16 *chan_setup = iqs7222->chan_setup[chan_index];
 	u16 *sys_setup = iqs7222->sys_setup;
@@ -2448,7 +2451,7 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
 	const struct iqs7222_dev_desc *dev_desc = iqs7222->dev_desc;
 	struct i2c_client *client = iqs7222->client;
 	int num_chan = dev_desc->reg_grps[IQS7222_REG_GRP_CHAN].num_row;
-	int ext_chan = rounddown(num_chan, 10);
+	int ext_chan = dev_desc->ext_chan ? : num_chan;
 	int count, error, reg_offset, i;
 	u16 *event_mask = &iqs7222->sys_setup[dev_desc->event_offset];
 	u16 *sldr_setup = iqs7222->sldr_setup[sldr_index];