linux-kernel - [PATCH v2 4/6] touchscreen/wacom_i2c: Clean up the query device fields

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 20 Jan 2021 22:56:41 -0800
From:   Alistair Francis <alistair@...stair23.me>
To:     dmitry.torokhov@...il.com, linux-input@...r.kernel.org,
        linux-imx@....com, kernel@...gutronix.de
Cc:     linux-kernel@...r.kernel.org, alistair23@...il.com,
        Alistair Francis <alistair@...stair23.me>
Subject: [PATCH v2 4/6] touchscreen/wacom_i2c: Clean up the query device fields

Improve the query device fields to be more verbose.

Signed-off-by: Alistair Francis <alistair@...stair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 73 +++++++++++++++++++--------
 1 file changed, 52 insertions(+), 21 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index 5f0b80d52ad5..a22570adc939 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -13,15 +13,32 @@
 #include <linux/irq.h>
 #include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
+#include <linux/reset.h>
 #include <linux/of.h>
 #include <asm/unaligned.h>
 
-#define WACOM_CMD_QUERY0	0x04
-#define WACOM_CMD_QUERY1	0x00
-#define WACOM_CMD_QUERY2	0x33
-#define WACOM_CMD_QUERY3	0x02
-#define WACOM_CMD_THROW0	0x05
-#define WACOM_CMD_THROW1	0x00
+// Registers
+#define WACOM_COMMAND_LSB   0x04
+#define WACOM_COMMAND_MSB   0x00
+
+#define WACOM_DATA_LSB      0x05
+#define WACOM_DATA_MSB      0x00
+
+// Report types
+#define REPORT_FEATURE      0x30
+
+// Requests / operations
+#define OPCODE_GET_REPORT   0x02
+
+// Power settings
+#define POWER_ON            0x00
+#define POWER_SLEEP         0x01
+
+// Input report ids
+#define WACOM_PEN_DATA_REPORT           2
+#define WACOM_SHINONOME_REPORT          26
+
+#define WACOM_QUERY_REPORT	3
 #define WACOM_QUERY_SIZE	22
 
 struct wacom_features {
@@ -45,34 +62,44 @@ struct wacom_i2c {
 };
 
 static int wacom_query_device(struct i2c_client *client,
-			      struct wacom_features *features)
+				  struct wacom_features *features)
 {
 	int ret;
-	u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
-			WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
-	u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
 	u8 data[WACOM_QUERY_SIZE];
+	struct reset_control *rstc;
+
+	u8 get_query_data_cmd[] = {
+		WACOM_COMMAND_LSB,
+		WACOM_COMMAND_MSB,
+		REPORT_FEATURE | WACOM_QUERY_REPORT,
+		OPCODE_GET_REPORT,
+		WACOM_DATA_LSB,
+		WACOM_DATA_MSB,
+	};
+
 	struct i2c_msg msgs[] = {
+		// Request reading of feature ReportID: 3 (Pen Query Data)
 		{
 			.addr = client->addr,
 			.flags = 0,
-			.len = sizeof(cmd1),
-			.buf = cmd1,
-		},
-		{
-			.addr = client->addr,
-			.flags = 0,
-			.len = sizeof(cmd2),
-			.buf = cmd2,
+			.len = sizeof(get_query_data_cmd),
+			.buf = get_query_data_cmd,
 		},
+		// Read 21 bytes
 		{
 			.addr = client->addr,
 			.flags = I2C_M_RD,
-			.len = sizeof(data),
+			.len = WACOM_QUERY_SIZE - 1,
 			.buf = data,
 		},
 	};
 
+	rstc = devm_reset_control_get_optional_exclusive(&client->dev, NULL);
+	if (IS_ERR(rstc))
+		dev_err(&client->dev, "Failed to get reset control before init\n");
+	else
+		reset_control_reset(rstc);
+
 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 	if (ret < 0)
 		return ret;
@@ -89,9 +116,13 @@ static int wacom_query_device(struct i2c_client *client,
 	features->tilt_y_max = get_unaligned_le16(&data[19]);
 
 	dev_dbg(&client->dev,
-		"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
+		"x_max:%d, y_max:%d, pressure:%d, fw:%d, "
+		"distance: %d, phys distance: %d, "
+		"tilt_x_max: %d, tilt_y_max: %d\n",
 		features->x_max, features->y_max,
-		features->pressure_max, features->fw_version);
+		features->pressure_max, features->fw_version,
+		features->distance_max, features->distance_physical_max,
+		features->tilt_x_max, features->tilt_y_max);
 
 	return 0;
 }
-- 
2.29.2