[PATCH 1/3 v2] Input: atmel_mxt_ts - Make wait-after-reset period compatible with all chips
From: Iiro Valkonen <hidden>
Date: 2011-07-04 12:58:06
Subsystem:
atmel maxtouch driver, input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Nick Dyer, Dmitry Torokhov, Linus Torvalds
The delay before the chip can be accessed after reset varies between different chips in maXTouch family. Waiting for 200ms and then monitoring the CHG (chip is ready when the line is low) is guaranteed to work with all chips. v2: At Dmitry's suggestion, add a timeout so we are not stuck looping endlessly in case the CHG is not going low. Signed-off-by: Iiro Valkonen <redacted> --- drivers/input/touchscreen/atmel_mxt_ts.c | 9 ++++++++- include/linux/i2c/atmel_mxt_ts.h | 1 + 2 files changed, 9 insertions(+), 1 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 1e61387..5469a29 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c@@ -170,7 +170,7 @@ #define MXT_BOOT_VALUE 0xa5 #define MXT_BACKUP_VALUE 0x55 #define MXT_BACKUP_TIME 25 /* msec */ -#define MXT_RESET_TIME 65 /* msec */ +#define MXT_RESET_TIME 200 /* msec */ #define MXT_FWRESET_TIME 175 /* msec */
@@ -792,6 +792,7 @@ static int mxt_initialize(struct mxt_data *data) struct i2c_client *client = data->client; struct mxt_info *info = &data->info; int error; + int reset_timeout = 0; u8 val; error = mxt_get_info(data);
@@ -828,6 +829,12 @@ static int mxt_initialize(struct mxt_data *data) mxt_write_object(data, MXT_GEN_COMMAND, MXT_COMMAND_RESET, 1); msleep(MXT_RESET_TIME); + while ((reset_timeout++ <= 100) && data->pdata->read_chg()) + msleep(2); + if (reset_timeout >= 100) { + dev_err(&client->dev, "No response after reset!\n"); + return -EIO; + } /* Update matrix size at info struct */ error = mxt_read_reg(client, MXT_MATRIX_X_SIZE, &val);
diff --git a/include/linux/i2c/atmel_mxt_ts.h b/include/linux/i2c/atmel_mxt_ts.h
index f027f7a..ef59c22 100644
--- a/include/linux/i2c/atmel_mxt_ts.h
+++ b/include/linux/i2c/atmel_mxt_ts.h@@ -39,6 +39,7 @@ struct mxt_platform_data { unsigned int voltage; unsigned char orient; unsigned long irqflags; + u8(*read_chg) (void); }; #endif /* __LINUX_ATMEL_MXT_TS_H */
--
1.7.0.4