Input: st1232 - simplify parsing of read buffer

Avoid complex 2-variable loop when parsing touchscreen data to make the
code clearer.

Acked-by: Martin Kepplinger <martink@posteo.de>
Tested-by: Matthias Fend <Matthias.Fend@wolfvision.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 1139714e72e2672f26a52be85280e7f8fea22e11..47033ef3749adfe31d3bdf7d45c4a08c0497d103 100644 (file)
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -57,38 +57,38 @@ static int st1232_ts_read_data(struct st1232_ts_data *ts)
 {
        struct st1232_ts_finger *finger = ts->finger;
        struct i2c_client *client = ts->client;
-       struct i2c_msg msg[2];
-       int error;
-       int i, y;
        u8 start_reg = ts->chip_info->start_reg;
-       u8 *buf = ts->read_buf;
-
-       /* read touchscreen data */
-       msg[0].addr = client->addr;
-       msg[0].flags = 0;
-       msg[0].len = 1;
-       msg[0].buf = &start_reg;
-
-       msg[1].addr = ts->client->addr;
-       msg[1].flags = I2C_M_RD;
-       msg[1].len = ts->read_buf_len;
-       msg[1].buf = buf;
+       struct i2c_msg msg[] = {
+               {
+                       .addr   = client->addr,
+                       .len    = sizeof(start_reg),
+                       .buf    = &start_reg,
+               },
+               {
+                       .addr   = client->addr,
+                       .flags  = I2C_M_RD,
+                       .len    = ts->read_buf_len,
+                       .buf    = ts->read_buf,
+               }
+       };
+       int ret;
+       int i;
+       u8 *buf;
 
-       error = i2c_transfer(client->adapter, msg, 2);
-       if (error < 0)
-               return error;
+       ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+       if (ret != ARRAY_SIZE(msg))
+               return ret < 0 ? ret : -EIO;
 
-       for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
-               finger[i].is_valid = buf[i + y] >> 7;
+       for (i = 0; i < ts->chip_info->max_fingers; i++) {
+               buf = &ts->read_buf[i * 4];
+               finger[i].is_valid = buf[0] >> 7;
                if (finger[i].is_valid) {
-                       finger[i].x = ((buf[i + y] & 0x0070) << 4) |
-                                       buf[i + y + 1];
-                       finger[i].y = ((buf[i + y] & 0x0007) << 8) |
-                                       buf[i + y + 2];
+                       finger[i].x = ((buf[0] & 0x70) << 4) | buf[1];
+                       finger[i].y = ((buf[0] & 0x07) << 8) | buf[2];
 
                        /* st1232 includes a z-axis / touch strength */
                        if (ts->chip_info->have_z)
-                               finger[i].t = buf[i + 6];
+                               finger[i].t = ts->read_buf[i + 6];
                }
        }