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>

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 3b07627dd8a28c23571bc7846601130df2eac7b5..5fb5b2231b5f9ac142823b08e2b6ba754b63d1bc 100644 (file)
--- 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);
        }