Input: atmel_mxt_ts - wait for CHG assert in mxt_check_bootloader

The driver should not immediately read bootloader status when in
Application Update Mode. The CHG line will assert when the device has made
a state transition and is ready to report a new status via i2c.

This change adds a wait for completion in mxt_check_bootloader, and changes
the mxt_interrupt handler to signal the completion.

Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
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 40af02c..7f51d39 100644 (file)
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -14,6 +14,8 @@
  */
 
 #include <linux/module.h>
+#include <linux/init.h>
+#include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/firmware.h>
 #include <linux/i2c.h>
@@ -246,16 +248,19 @@ struct mxt_data {
        const struct mxt_platform_data *pdata;
        struct mxt_object *object_table;
        struct mxt_info info;
-
        unsigned int irq;
        unsigned int max_x;
        unsigned int max_y;
+       bool in_bootloader;
 
        /* Cached parameters from object table */
        u8 T6_reportid;
        u8 T9_reportid_min;
        u8 T9_reportid_max;
        u8 T19_reportid;
+
+       /* for fw update in bootloader */
+       struct completion bl_completion;
 };
 
 static size_t mxt_obj_size(const struct mxt_object *obj)
@@ -339,12 +344,50 @@ static void mxt_dump_message(struct device *dev,
                message->reportid, 7, message->message);
 }
 
-static int mxt_check_bootloader(struct i2c_client *client,
-                                    unsigned int state)
+static int mxt_wait_for_chg(struct mxt_data *data, unsigned int timeout_ms)
 {
+       struct device *dev = &data->client->dev;
+       struct completion *comp = &data->bl_completion;
+       unsigned long timeout = msecs_to_jiffies(timeout_ms);
+       long ret;
+
+       ret = wait_for_completion_interruptible_timeout(comp, timeout);
+       if (ret < 0) {
+               return ret;
+       } else if (ret == 0) {
+               dev_err(dev, "Wait for completion timed out.\n");
+               return -ETIMEDOUT;
+       }
+       return 0;
+}
+
+static int mxt_check_bootloader(struct mxt_data *data, unsigned int state)
+{
+       struct i2c_client *client = data->client;
        u8 val;
+       int ret;
 
 recheck:
+       if (state != MXT_WAITING_BOOTLOAD_CMD) {
+               /*
+                * In application update mode, the interrupt
+                * line signals state transitions. We must wait for the
+                * CHG assertion before reading the status byte.
+                * Once the status byte has been read, the line is deasserted.
+                */
+               ret = mxt_wait_for_chg(data, 300);
+               if (ret) {
+                       /*
+                        * TODO: handle -ERESTARTSYS better by terminating
+                        * fw update process before returning to userspace
+                        * by writing length 0x000 to device (iff we are in
+                        * WAITING_FRAME_DATA state).
+                        */
+                       dev_err(&client->dev, "Update wait error %d\n", ret);
+                       return ret;
+               }
+       }
+
        if (i2c_master_recv(client, &val, 1) != 1) {
                dev_err(&client->dev, "%s: i2c recv failed\n", __func__);
                return -EIO;
@@ -590,9 +633,8 @@ static bool mxt_is_T9_message(struct mxt_data *data, struct mxt_message *msg)
        return (id >= data->T9_reportid_min && id <= data->T9_reportid_max);
 }
 
-static irqreturn_t mxt_interrupt(int irq, void *dev_id)
+static irqreturn_t mxt_process_messages_until_invalid(struct mxt_data *data)
 {
-       struct mxt_data *data = dev_id;
        struct mxt_message message;
        const u8 *payload = &message.message[0];
        struct device *dev = &data->client->dev;
@@ -632,6 +674,19 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
+static irqreturn_t mxt_interrupt(int irq, void *dev_id)
+{
+       struct mxt_data *data = dev_id;
+
+       if (data->in_bootloader) {
+               /* bootloader state transition completion */
+               complete(&data->bl_completion);
+               return IRQ_HANDLED;
+       }
+
+       return mxt_process_messages_until_invalid(data);
+}
+
 static int mxt_check_reg_init(struct mxt_data *data)
 {
        const struct mxt_platform_data *pdata = data->pdata;
@@ -947,6 +1002,8 @@ static int mxt_load_fw(struct device *dev, const char *fn)
        }
 
        /* Change to the bootloader mode */
+       data->in_bootloader = true;
+
        mxt_write_object(data, MXT_GEN_COMMAND_T6,
                        MXT_COMMAND_RESET, MXT_BOOT_VALUE);
        msleep(MXT_RESET_TIME);
@@ -957,18 +1014,19 @@ static int mxt_load_fw(struct device *dev, const char *fn)
        else
                client->addr = MXT_BOOT_HIGH;
 
-       ret = mxt_check_bootloader(client, MXT_WAITING_BOOTLOAD_CMD);
+       reinit_completion(&data->bl_completion);
+
+       ret = mxt_check_bootloader(data, MXT_WAITING_BOOTLOAD_CMD);
        if (ret)
-               goto out;
+               goto disable_irq;
 
        /* Unlock bootloader */
        mxt_unlock_bootloader(client);
 
        while (pos < fw->size) {
-               ret = mxt_check_bootloader(client,
-                                               MXT_WAITING_FRAME_DATA);
+               ret = mxt_check_bootloader(data, MXT_WAITING_FRAME_DATA);
                if (ret)
-                       goto out;
+                       goto disable_irq;
 
                frame_size = ((*(fw->data + pos) << 8) | *(fw->data + pos + 1));
 
@@ -980,17 +1038,19 @@ static int mxt_load_fw(struct device *dev, const char *fn)
                /* Write one frame to device */
                mxt_fw_write(client, fw->data + pos, frame_size);
 
-               ret = mxt_check_bootloader(client,
-                                               MXT_FRAME_CRC_PASS);
+               ret = mxt_check_bootloader(data, MXT_FRAME_CRC_PASS);
                if (ret)
-                       goto out;
+                       goto disable_irq;
 
                pos += frame_size;
 
                dev_dbg(dev, "Updated %d bytes / %zd bytes\n", pos, fw->size);
        }
 
-out:
+       data->in_bootloader = false;
+
+disable_irq:
+       disable_irq(data->irq);
        release_firmware(fw);
 
        /* Change to slave address of application */
@@ -1009,8 +1069,6 @@ static ssize_t mxt_update_fw_store(struct device *dev,
        struct mxt_data *data = dev_get_drvdata(dev);
        int error;
 
-       disable_irq(data->irq);
-
        error = mxt_load_fw(dev, MXT_FW_NAME);
        if (error) {
                dev_err(dev, "The firmware update failed(%d)\n", error);
@@ -1024,13 +1082,13 @@ static ssize_t mxt_update_fw_store(struct device *dev,
                mxt_free_object_table(data);
 
                mxt_initialize(data);
-       }
 
-       enable_irq(data->irq);
+               enable_irq(data->irq);
 
-       error = mxt_make_highchg(data);
-       if (error)
-               return error;
+               error = mxt_make_highchg(data);
+               if (error)
+                       return error;
+       }
 
        return count;
 }
@@ -1120,6 +1178,8 @@ static int mxt_probe(struct i2c_client *client,
        data->pdata = pdata;
        data->irq = client->irq;
 
+       init_completion(&data->bl_completion);
+
        mxt_calc_resolution(data);
 
        error = mxt_initialize(data);