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From: "jeffrey.lin" <yajohn@gmail.com>
Newsgroups: linux.kernel
Subject: [PATCH] [v1.1 1/3] driver: input :touchscreen : add Raydium crc touch function
Date: Thu, 07 Jul 2016 18:40:01 +0200
Message-ID: <rSkvf-ZX-7@gated-at.bofh.it>
Sender: robomod@news.nic.it
Approved: robomod@news.nic.it
Lines: 171
Organization: linux.* mail to news gateway
Xref: csiph.com linux.kernel:1438718

add checksum for touch report points.

Signed-off-by: jeffrey.lin <jeffrey.lin@rad-ic.com>
---
 drivers/input/touchscreen/raydium_i2c_ts.c | 86 +++++++++++++++++++-----------
 1 file changed, 56 insertions(+), 30 deletions(-)

diff --git a/drivers/input/touchscreen/raydium_i2c_ts.c b/drivers/input/touchscreen/raydium_i2c_ts.c
index f3076d9..de31b41 100644
--- a/drivers/input/touchscreen/raydium_i2c_ts.c
+++ b/drivers/input/touchscreen/raydium_i2c_ts.c
@@ -70,6 +70,8 @@
 #define RM_CONTACT_WIDTH_X_POS	6
 #define RM_CONTACT_WIDTH_Y_POS	7
 
+#define RM_CONTACT_CRC_OFFSET	2
+
 /* Bootloader relative info */
 #define RM_BL_WRT_CMD_SIZE	3	/* bl flash wrt cmd size */
 #define RM_BL_WRT_PKG_SIZE	32	/* bl wrt pkg size */
@@ -137,6 +139,7 @@ struct raydium_data {
 	u32 data_bank_addr;
 	u8 report_size;
 	u8 contact_size;
+	u8 pkg_size;
 
 	enum raydium_boot_mode boot_mode;
 
@@ -280,12 +283,14 @@ static int raydium_i2c_query_ts_info(struct raydium_data *ts)
 		 * then the size changed (due to firmware update?) and keep
 		 * old size instead.
 		 */
-		if (ts->report_data && ts->report_size != data_info.pkg_size)
+		if (ts->report_data && ts->pkg_size != data_info.pkg_size)
 			dev_warn(&client->dev,
 				 "report size changes, was: %d, new: %d\n",
-				 ts->report_size, data_info.pkg_size);
-		else
-			ts->report_size = data_info.pkg_size;
+				 ts->pkg_size, data_info.pkg_size);
+		else {
+			ts->pkg_size = data_info.pkg_size;
+			ts->report_size = ts->pkg_size - RM_CONTACT_CRC_OFFSET;
+		}
 
 		ts->contact_size = data_info.tp_info_size;
 		ts->data_bank_addr = le32_to_cpu(data_info.data_bank_addr);
@@ -612,6 +617,17 @@ static int raydium_i2c_fw_write_page(struct i2c_client *client,
 	return error;
 }
 
+static u16 raydium_calc_chksum(const u8 *buf, u16 len)
+{
+	u16 checksum = 0;
+	u16 i;
+
+	for (i = 0; i < len; i++)
+		checksum += buf[i];
+
+	return checksum;
+}
+
 static int raydium_i2c_do_update_firmware(struct raydium_data *ts,
 					 const struct firmware *fw)
 {
@@ -724,9 +740,7 @@ static int raydium_i2c_do_update_firmware(struct raydium_data *ts,
 		return error;
 	}
 
-	fw_checksum = 0;
-	for (i = 0; i < fw->size; i++)
-		fw_checksum += fw->data[i];
+	fw_checksum = raydium_calc_chksum(fw->data, fw->size);
 
 	error = raydium_i2c_write_checksum(client, fw->size, fw_checksum);
 	if (error)
@@ -780,15 +794,6 @@ out_enable_irq:
 static void raydium_mt_event(struct raydium_data *ts)
 {
 	int i;
-	int error;
-
-	error = raydium_i2c_read_message(ts->client, ts->data_bank_addr,
-					 ts->report_data, ts->report_size);
-	if (error) {
-		dev_err(&ts->client->dev, "%s: failed to read data: %d\n",
-			__func__, error);
-		return;
-	}
 
 	for (i = 0; i < ts->report_size / ts->contact_size; i++) {
 		u8 *contact = &ts->report_data[ts->contact_size * i];
@@ -798,33 +803,54 @@ static void raydium_mt_event(struct raydium_data *ts)
 		input_mt_slot(ts->input, i);
 		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, state);
 
-		if (!state)
-			continue;
-
-		input_report_abs(ts->input, ABS_MT_POSITION_X,
+		if (state == 0x01) {
+			input_report_abs(ts->input, ABS_MT_POSITION_X,
 				get_unaligned_le16(&contact[RM_CONTACT_X_POS]));
-		input_report_abs(ts->input, ABS_MT_POSITION_Y,
+			input_report_abs(ts->input, ABS_MT_POSITION_Y,
 				get_unaligned_le16(&contact[RM_CONTACT_Y_POS]));
-		input_report_abs(ts->input, ABS_MT_PRESSURE,
-				contact[RM_CONTACT_PRESSURE_POS]);
+			input_report_abs(ts->input, ABS_MT_PRESSURE,
+					contact[RM_CONTACT_PRESSURE_POS]);
 
-		wx = contact[RM_CONTACT_WIDTH_X_POS];
-		wy = contact[RM_CONTACT_WIDTH_Y_POS];
+			wx = contact[RM_CONTACT_WIDTH_X_POS];
+			wy = contact[RM_CONTACT_WIDTH_Y_POS];
 
-		input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, max(wx, wy));
-		input_report_abs(ts->input, ABS_MT_TOUCH_MINOR, min(wx, wy));
+			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
+				max(wx, wy));
+			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
+				min(wx, wy));
+		}
 	}
 
 	input_mt_sync_frame(ts->input);
 	input_sync(ts->input);
 }
 
+static void raydium_i2c_event(struct raydium_data *ts)
+{
+	u16 fw_crc;
+	u16 calc_crc = raydium_calc_chksum(ts->report_data, ts->report_size);
+
+	fw_crc = get_unaligned_le16(&ts->report_data[ts->report_size]);
+
+	if (unlikely(fw_crc != calc_crc))
+		dev_warn(&ts->client->dev,
+			 "%s: invalid packet crc %04x &. %04x\n",
+			 __func__, calc_crc, fw_crc);
+	else
+		raydium_mt_event(ts);
+}
+
 static irqreturn_t raydium_i2c_irq(int irq, void *_dev)
 {
 	struct raydium_data *ts = _dev;
+	int error;
 
-	if (ts->boot_mode != RAYDIUM_TS_BLDR)
-		raydium_mt_event(ts);
+	if (ts->boot_mode == RAYDIUM_TS_MAIN) {
+		error = raydium_i2c_read_message(ts->client, ts->data_bank_addr,
+				 ts->report_data, ts->pkg_size);
+		if (!error)
+			raydium_i2c_event(ts);
+	}
 
 	return IRQ_HANDLED;
 }
@@ -1050,7 +1076,7 @@ static int raydium_i2c_probe(struct i2c_client *client,
 	}
 
 	ts->report_data = devm_kmalloc(&client->dev,
-				       ts->report_size, GFP_KERNEL);
+				       ts->pkg_size, GFP_KERNEL);
 	if (!ts->report_data)
 		return -ENOMEM;
 
-- 
2.1.2