[PATCH AUTOSEL 4.19 066/172] Input: mms114 - add extra compatible for mms345l

[Sasha Levin <sashal@kernel.org>]

From: Stephan Gerhold <stephan@gerhold.net>

[ Upstream commit 7842087b0196d674ed877d768de8f2a34d7fdc53 ]

MMS345L is another first generation touch screen from Melfas,
which uses mostly the same registers as MMS152.

However, there is some garbage printed during initialization.
Apparently MMS345L does not have the MMS152_COMPAT_GROUP register
that is read+printed during initialization.

  TSP FW Rev: bootloader 0x6 / core 0x26 / config 0x26, Compat group: \x06

On earlier kernel versions the compat group was actually printed as
an ASCII control character, seems like it gets escaped now.

But we probably shouldn't print something from a random register.

Add a separate "melfas,mms345l" compatible that avoids reading
from the MMS152_COMPAT_GROUP register. This might also help in case
there is some other device-specific quirk in the future.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Andi Shyti <andi@etezian.org>
Link: https://lore.kernel.org/r/20200423102431.2715-1-stephan@gerhold.net
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/input/touchscreen/mms114.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/mms114.c b/drivers/input/touchscreen/mms114.c
index a5ab774da4cc..a31b593f5b5f 100644
--- a/drivers/input/touchscreen/mms114.c
+++ b/drivers/input/touchscreen/mms114.c
@@ -54,6 +54,7 @@
 enum mms_type {
 	TYPE_MMS114	= 114,
 	TYPE_MMS152	= 152,
+	TYPE_MMS345L	= 345,
 };
 
 struct mms114_data {
@@ -250,6 +251,15 @@ static int mms114_get_version(struct mms114_data *data)
 	int error;
 
 	switch (data->type) {
+	case TYPE_MMS345L:
+		error = __mms114_read_reg(data, MMS152_FW_REV, 3, buf);
+		if (error)
+			return error;
+
+		dev_info(dev, "TSP FW Rev: bootloader 0x%x / core 0x%x / config 0x%x\n",
+			 buf[0], buf[1], buf[2]);
+		break;
+
 	case TYPE_MMS152:
 		error = __mms114_read_reg(data, MMS152_FW_REV, 3, buf);
 		if (error)
@@ -287,8 +297,8 @@ static int mms114_setup_regs(struct mms114_data *data)
 	if (error < 0)
 		return error;
 
-	/* MMS152 has no configuration or power on registers */
-	if (data->type == TYPE_MMS152)
+	/* Only MMS114 has configuration and power on registers */
+	if (data->type != TYPE_MMS114)
 		return 0;
 
 	error = mms114_set_active(data, true);
@@ -600,6 +610,9 @@ static const struct of_device_id mms114_dt_match[] = {
 	}, {
 		.compatible = "melfas,mms152",
 		.data = (void *)TYPE_MMS152,
+	}, {
+		.compatible = "melfas,mms345l",
+		.data = (void *)TYPE_MMS345L,
 	},
 	{ }
 };
-- 
2.25.1