[PATCH 08/10] Input: atmel_mxt_ts - wait for CHG assert in mxt_check_bootloader

From: Daniel Kurtz
Date: Fri Feb 01 2013 - 03:12:46 EST


From: Benson Leung <bleung@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 63 ++++++++++++++++++++++++++++----
1 file changed, 55 insertions(+), 8 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index be96be3..d0f91ff 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -13,6 +13,7 @@

#include <linux/module.h>
#include <linux/init.h>
+#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
@@ -251,6 +252,9 @@ struct mxt_data {
u8 T6_reportid;
u8 T9_reportid_min;
u8 T9_reportid_max;
+
+ /* for fw update in bootloader */
+ struct completion bl_completion;
};

static void mxt_free_object_table(struct mxt_data *data);
@@ -381,19 +385,58 @@ static int mxt_i2c_transfer(struct i2c_client *client, struct i2c_msg *msgs,
return ret;
}

-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) {
+ dev_err(dev, "Wait for completion interrupted.\n");
+ /*
+ * TODO: handle -EINTR better by terminating fw update process
+ * before returning to userspace by writing length 0x000 to
+ * device (iff we are in WAITING_FRAME_DATA state).
+ */
+ return -EINTR;
+ } 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.
+ */
+ int ret = mxt_wait_for_chg(data, 300);
+ if (ret) {
+ dev_err(&client->dev, "Update wait error %d\n", ret);
+ return ret;
+ }
+ }
+
ret = mxt_i2c_recv(client, &val, 1);
if (ret)
return ret;

switch (state) {
case MXT_WAITING_BOOTLOAD_CMD:
+ dev_info(&client->dev, "bootloader version: %d\n",
+ val & MXT_BOOT_STATUS_MASK);
case MXT_WAITING_FRAME_DATA:
val &= ~MXT_BOOT_STATUS_MASK;
break;
@@ -672,8 +715,11 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
u8 reportid;
bool update_input = false;

- if (mxt_in_bootloader(data))
+ if (mxt_in_bootloader(data)) {
+ /* bootloader state transition completion */
+ complete(&data->bl_completion);
goto end;
+ }

do {
if (mxt_read_message(data, &message)) {
@@ -1072,18 +1118,18 @@ static int mxt_load_fw(struct device *dev, const char *fn)
goto out;
}

- ret = mxt_check_bootloader(client, MXT_WAITING_BOOTLOAD_CMD);
+ ret = mxt_check_bootloader(data, MXT_WAITING_BOOTLOAD_CMD);
if (ret)
goto out;

+ INIT_COMPLETION(data->bl_completion);
/* Unlock bootloader */
ret = mxt_unlock_bootloader(client);
if (ret)
goto out;

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;

@@ -1099,8 +1145,7 @@ static int mxt_load_fw(struct device *dev, const char *fn)
if (ret)
goto out;

- ret = mxt_check_bootloader(client,
- MXT_FRAME_CRC_PASS);
+ ret = mxt_check_bootloader(data, MXT_FRAME_CRC_PASS);
if (ret)
goto out;

@@ -1264,6 +1309,8 @@ static int __devinit mxt_probe(struct i2c_client *client,
data->pdata = pdata;
data->irq = client->irq;

+ init_completion(&data->bl_completion);
+
mxt_calc_resolution(data);

if (mxt_in_bootloader(data)) {
--
1.8.1

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