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>

1 files changed, 43 insertions, 10 deletions

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index d2feb9c771a4..95e3ef49ac9b 100644
--- 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;