[PATCH 09/51] Input: atmel_mxt_ts - Make wait-after-reset period compatible with all chips

From: Nick Dyer
Date: Thu Jun 27 2013 - 09:07:09 EST

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From: Iiro Valkonen <iiro.valkonen@xxxxxxxxx>

The delay before the chip can be accessed after reset varies between different
chips in maXTouch family. Waiting for an interrupt and a T6 status message
with the RESET bit set is a better behaviour.

Signed-off-by: Nick Dyer <nick.dyer@xxxxxxxxxxx>
Acked-by: Benson Leung <bleung@xxxxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 109 ++++++++++++++++++++++++------
1 file changed, 87 insertions(+), 22 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 1e24e54..11ee78a 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -88,6 +88,9 @@
#define MXT_COMMAND_REPORTALL 3
#define MXT_COMMAND_DIAGNOSTIC 5

+/* Define for T6 status byte */
+#define MXT_T6_STATUS_RESET (1 << 7)
+
/* MXT_GEN_POWER_T7 field */
#define MXT_POWER_IDLEACQINT 0
#define MXT_POWER_ACTVACQINT 1
@@ -179,9 +182,13 @@

/* Define for MXT_GEN_COMMAND_T6 */
#define MXT_BOOT_VALUE 0xa5
+#define MXT_RESET_VALUE 0x01
#define MXT_BACKUP_VALUE 0x55
+
+/* Delay times */
#define MXT_BACKUP_TIME 50 /* msec */
#define MXT_RESET_TIME 200 /* msec */
+#define MXT_RESET_TIMEOUT 3000 /* msec */
#define MXT_FW_RESET_TIME 3000 /* msec */
#define MXT_FW_CHG_TIMEOUT 300 /* msec */

@@ -256,6 +263,7 @@ struct mxt_data {

/* Cached parameters from object table */
u8 T6_reportid;
+ u16 T6_address;
u8 T9_reportid_min;
u8 T9_reportid_max;
u8 T19_reportid;
@@ -263,6 +271,9 @@ struct mxt_data {
/* for fw update in bootloader */
struct completion bl_completion;

+ /* for reset handling */
+ struct completion reset_completion;
+
/* Enable reporting of input events */
bool enable_reporting;
};
@@ -348,10 +359,10 @@ static void mxt_dump_message(struct device *dev,
message->reportid, 7, message->message);
}

-static int mxt_wait_for_chg(struct mxt_data *data, unsigned int timeout_ms)
+static int mxt_wait_for_completion(struct mxt_data *data,
+ struct completion *comp, 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;

@@ -380,7 +391,8 @@ recheck:
* CHG assertion before reading the status byte.
* Once the status byte has been read, the line is deasserted.
*/
- ret = mxt_wait_for_chg(data, MXT_FW_CHG_TIMEOUT);
+ ret = mxt_wait_for_completion(data, &data->bl_completion,
+ MXT_FW_CHG_TIMEOUT);
if (ret) {
/*
* TODO: handle -EINTR better by terminating fw update
@@ -667,6 +679,9 @@ static irqreturn_t mxt_process_messages_until_invalid(struct mxt_data *data)
unsigned csum = mxt_extract_T6_csum(&payload[1]);
dev_dbg(dev, "Status: %02x Config Checksum: %06x\n",
status, csum);
+
+ if (status & MXT_T6_STATUS_RESET)
+ complete(&data->reset_completion);
} else if (mxt_is_T9_message(data, &message)) {
int id = reportid - data->T9_reportid_min;
mxt_input_touchevent(data, &message, id);
@@ -703,6 +718,59 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
return mxt_process_messages_until_invalid(data);
}

+static int mxt_t6_command(struct mxt_data *data, u16 cmd_offset,
+ u8 value, bool wait)
+{
+ u16 reg;
+ u8 command_register;
+ int timeout_counter = 0;
+ int ret;
+
+ reg = data->T6_address + cmd_offset;
+
+ ret = mxt_write_reg(data->client, reg, value);
+ if (ret)
+ return ret;
+
+ if (!wait)
+ return 0;
+
+ do {
+ msleep(20);
+ ret = __mxt_read_reg(data->client, reg, 1, &command_register);
+ if (ret)
+ return ret;
+ } while ((command_register != 0) && (timeout_counter++ <= 100));
+
+ if (timeout_counter > 100) {
+ dev_err(&data->client->dev, "Command failed!\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int mxt_soft_reset(struct mxt_data *data)
+{
+ struct device *dev = &data->client->dev;
+ int ret = 0;
+
+ dev_info(dev, "Resetting chip\n");
+
+ INIT_COMPLETION(data->reset_completion);
+
+ ret = mxt_t6_command(data, MXT_COMMAND_RESET, MXT_RESET_VALUE, false);
+ if (ret)
+ return ret;
+
+ ret = mxt_wait_for_completion(data, &data->reset_completion,
+ MXT_RESET_TIMEOUT);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static int mxt_check_reg_init(struct mxt_data *data)
{
const struct mxt_platform_data *pdata = data->pdata;
@@ -829,6 +897,7 @@ static int mxt_get_object_table(struct mxt_data *data)
switch (object->type) {
case MXT_GEN_COMMAND_T6:
data->T6_reportid = min_id;
+ data->T6_address = object->start_address;
break;
case MXT_TOUCH_MULTI_T9:
data->T9_reportid_min = min_id;
@@ -887,16 +956,10 @@ static int mxt_initialize(struct mxt_data *data)
if (error)
goto err_free_object_table;

- /* Backup to memory */
- mxt_write_object(data, MXT_GEN_COMMAND_T6,
- MXT_COMMAND_BACKUPNV,
- MXT_BACKUP_VALUE);
- msleep(MXT_BACKUP_TIME);
-
- /* Soft reset */
- mxt_write_object(data, MXT_GEN_COMMAND_T6,
- MXT_COMMAND_RESET, 1);
- msleep(MXT_RESET_TIME);
+ error = mxt_t6_command(data, MXT_COMMAND_BACKUPNV,
+ MXT_BACKUP_VALUE, false);
+ if (!error)
+ mxt_soft_reset(data);

/* Update matrix size at info struct */
error = mxt_read_reg(client, MXT_MATRIX_X_SIZE, &val);
@@ -1040,8 +1103,10 @@ 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);
+ ret = mxt_t6_command(data, MXT_COMMAND_RESET, MXT_BOOT_VALUE, false);
+ if (ret)
+ goto release_firmware;
+
msleep(MXT_RESET_TIME);

/* Change to slave address of bootloader */
@@ -1084,18 +1149,21 @@ static int mxt_load_fw(struct device *dev, const char *fn)
}

/* Wait for flash. */
- ret = mxt_wait_for_chg(data, MXT_FW_RESET_TIME);
+ ret = mxt_wait_for_completion(data, &data->bl_completion,
+ MXT_FW_RESET_TIME);
if (ret)
goto disable_irq;

/* Wait for device to reset. Some bootloader versions do not assert
* the CHG line after bootloading has finished, so ignore error */
- mxt_wait_for_chg(data, MXT_FW_RESET_TIME);
+ mxt_wait_for_completion(data, &data->bl_completion,
+ MXT_FW_RESET_TIME);

data->in_bootloader = false;

disable_irq:
disable_irq(data->irq);
+release_firmware:
release_firmware(fw);

/* Change to slave address of application */
@@ -1216,6 +1284,7 @@ static int mxt_probe(struct i2c_client *client,
data->irq = client->irq;

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

mxt_calc_resolution(data);

@@ -1341,11 +1410,7 @@ static int mxt_resume(struct device *dev)
struct mxt_data *data = i2c_get_clientdata(client);
struct input_dev *input_dev = data->input_dev;

- /* Soft reset */
- mxt_write_object(data, MXT_GEN_COMMAND_T6,
- MXT_COMMAND_RESET, 1);
-
- msleep(MXT_RESET_TIME);
+ mxt_soft_reset(data);

mutex_lock(&input_dev->mutex);

--
1.7.10.4

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Next message: Nick Dyer: "Atmel updates to atmel_mxt_ts touch controller driver - v6"
Previous message: Arnd Bergmann: "Re: [GIT PULL] at91: non critical fixes (for early 3.11) #2"
In reply to: Nick Dyer: "[PATCH 08/51] Input: atmel_mxt_ts - Initialise IRQ before probing"
Next in thread: Nick Dyer: "[PATCH 07/51] Input: atmel_mxt_ts - wait for CHG after bootloader resets"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]