Input: atmel_mxt_ts - implement bootloader frame retries

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Benson Leung <bleung@chromium.org>
Acked-by: Yufeng Shen <miletus@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 20 insertions, 7 deletions

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 3b07627dd8a2..5fb5b2231b5f 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -510,8 +510,12 @@ recheck:
                 val &= ~MXT_BOOT_STATUS_MASK;
                 break;
         case MXT_FRAME_CRC_PASS:
-                if (val == MXT_FRAME_CRC_CHECK)
+                if (val == MXT_FRAME_CRC_CHECK) {
                         goto recheck;
+                } else if (val == MXT_FRAME_CRC_FAIL) {
+                        dev_err(dev, "Bootloader CRC fail\n");
+                        return -EINVAL;
+                }
                 break;
         default:
                 return -EINVAL;
@@ -1187,6 +1191,7 @@ static int mxt_load_fw(struct device *dev, const char *fn)
         const struct firmware *fw = NULL;
         unsigned int frame_size;
         unsigned int pos = 0;
+        unsigned int retry = 0;
         int ret;
 
         ret = request_firmware(&fw, fn, dev);
@@ -1224,9 +1229,7 @@ static int mxt_load_fw(struct device *dev, const char *fn)
 
                 frame_size = ((*(fw->data + pos) << 8) | *(fw->data + pos + 1));
 
-                /* We should add 2 at frame size as the the firmware data is not
-                 * included the CRC bytes.
-                 */
+                /* Take account of CRC bytes */
                 frame_size += 2;
 
                 /* Write one frame to device */
@@ -1235,10 +1238,20 @@ static int mxt_load_fw(struct device *dev, const char *fn)
                         goto disable_irq;
 
                 ret = mxt_check_bootloader(data, MXT_FRAME_CRC_PASS);
-                if (ret)
-                        goto disable_irq;
+                if (ret) {
+                        retry++;
+
+                        /* Back off by 20ms per retry */
+                        msleep(retry * 20);
 
-                pos += frame_size;
+                        if (retry > 20) {
+                                dev_err(dev, "Retry count exceeded\n");
+                                goto disable_irq;
+                        }
+                } else {
+                        retry = 0;
+                        pos += frame_size;
+                }
 
                 dev_dbg(dev, "Updated %d bytes / %zd bytes\n", pos, fw->size);
         }