Input: atmel_mxt_ts - handle APP_CRC_FAIL on startup

If the bootloader on the touchscreen controller fails to initialise the
firmware image, it stays in bootloader mode and reports a failure. It is
possible to reflash a working firmware image from this state.

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 d2feb9c771a406e29d7c43b69f817cef9b7ae757..95e3ef49ac9b226f514407820239c3002e8b71b2 100644 (file)
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -404,6 +404,30 @@ static int mxt_lookup_bootloader_address(struct mxt_data *data)
        return 0;
 }
 
+static int mxt_probe_bootloader(struct mxt_data *data)
+{
+       struct device *dev = &data->client->dev;
+       int ret;
+       u8 val;
+       bool crc_failure;
+
+       ret = mxt_lookup_bootloader_address(data);
+       if (ret)
+               return ret;
+
+       ret = mxt_bootloader_read(data, &val, 1);
+       if (ret)
+               return ret;
+
+       /* Check app crc fail mode */
+       crc_failure = (val & ~MXT_BOOT_STATUS_MASK) == MXT_APP_CRC_FAIL;
+
+       dev_err(dev, "Detected bootloader, status:%02X%s\n",
+                       val, crc_failure ? ", APP_CRC_FAIL" : "");
+
+       return 0;
+}
+
 static u8 mxt_get_bootloader_version(struct mxt_data *data, u8 val)
 {
        struct device *dev = &data->client->dev;
@@ -463,6 +487,7 @@ recheck:
        switch (state) {
        case MXT_WAITING_BOOTLOAD_CMD:
        case MXT_WAITING_FRAME_DATA:
+       case MXT_APP_CRC_FAIL:
                val &= ~MXT_BOOT_STATUS_MASK;
                break;
        case MXT_FRAME_CRC_PASS:
@@ -1451,8 +1476,14 @@ static int mxt_initialize(struct mxt_data *data)
        int error;
 
        error = mxt_get_info(data);
-       if (error)
-               return error;
+       if (error) {
+               error = mxt_probe_bootloader(data);
+               if (error)
+                       return error;
+
+               data->in_bootloader = true;
+               return 0;
+       }
 
        /* Get object table information */
        error = mxt_get_object_table(data);
@@ -1630,15 +1661,19 @@ static int mxt_load_fw(struct device *dev, const char *fn)
        if (ret)
                goto release_firmware;
 
-       /* Change to the bootloader mode */
-       data->in_bootloader = true;
+       if (!data->in_bootloader) {
+               /* Change to the bootloader mode */
+               data->in_bootloader = true;
 
-       ret = mxt_t6_command(data, MXT_COMMAND_RESET, MXT_BOOT_VALUE, false);
-       if (ret)
-               goto release_firmware;
+               ret = mxt_t6_command(data, MXT_COMMAND_RESET,
+                                    MXT_BOOT_VALUE, false);
+               if (ret)
+                       goto release_firmware;
 
-       msleep(MXT_RESET_TIME);
+               msleep(MXT_RESET_TIME);
+       }
 
+       mxt_free_object_table(data);
        reinit_completion(&data->bl_completion);
 
        ret = mxt_check_bootloader(data, MXT_WAITING_BOOTLOAD_CMD);
@@ -1723,8 +1758,6 @@ static ssize_t mxt_update_fw_store(struct device *dev,
        } else {
                dev_info(dev, "The firmware update succeeded\n");
 
-               mxt_free_object_table(data);
-
                error = mxt_initialize(data);
                if (error)
                        return error;