Input: atmel_mxt_ts - optimize reading objects in object sysfs entry

Read each object in a single i2c transaction instead of byte-by-byte

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 15 insertions, 20 deletions

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 55855b8c2efd..94dd1d156a98 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -479,20 +479,6 @@ static int mxt_read_message(struct mxt_data *data,
                         sizeof(struct mxt_message), message);
 }
 
-static int mxt_read_object(struct mxt_data *data,
-                                u8 type, u8 offset, u8 *val)
-{
-        struct mxt_object *object;
-        u16 reg;
-
-        object = mxt_get_object(data, type);
-        if (!object)
-                return -EINVAL;
-
-        reg = object->start_address;
-        return __mxt_read_reg(data->client, reg + offset, 1, val);
-}
-
 static int mxt_write_object(struct mxt_data *data,
                                  u8 type, u8 offset, u8 val)
 {
@@ -900,7 +886,14 @@ static ssize_t mxt_object_show(struct device *dev,
         int i, j;
         int error;
         u8 val;
+        u8 *obuf;
+
+        /* Pre-allocate buffer large enough to hold max sized object. */
+        obuf = kmalloc(256, GFP_KERNEL);
+        if (!obuf)
+                return -ENOMEM;
 
+        error = 0;
         for (i = 0; i < data->info.object_num; i++) {
                 object = data->object_table + i;
 
@@ -914,20 +907,22 @@ static ssize_t mxt_object_show(struct device *dev,
                         continue;
                 }
 
+                error = __mxt_read_reg(data->client, object->start_address,
+                                object->size + 1, obuf);
+                if (error)
+                        break;
+
                 for (j = 0; j < object->size + 1; j++) {
-                        error = mxt_read_object(data,
-                                                object->type, j, &val);
-                        if (error)
-                                return error;
+                        val = obuf[j];
 
                         count += scnprintf(buf + count, PAGE_SIZE - count,
                                         "\t[%2d]: %02x (%d)\n", j, val, val);
                 }
-
                 count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
         }
 
-        return count;
+        kfree(obuf);
+        return error ?: count;
 }
 
 static int mxt_load_fw(struct device *dev, const char *fn)