| Message ID | 4E145128.9060404@atmel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/07/2011 05:43 PM, Dmitry Torokhov wrote: > On Wed, Jul 06, 2011 at 03:12:24PM +0300, Iiro Valkonen wrote: >> 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. >> >> v3: Add a check for NULL read_chg() function, and add the read_chg() to platform >> files using this driver (currently only mach-goni.c) >> 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 <iiro.valkonen@atmel.com> >> --- >> arch/arm/mach-s5pv210/mach-goni.c | 6 ++++++ >> drivers/input/touchscreen/atmel_mxt_ts.c | 14 +++++++++++++- >> include/linux/i2c/atmel_mxt_ts.h | 1 + >> 3 files changed, 20 insertions(+), 1 deletions(-) >> >> diff --git a/arch/arm/mach-s5pv210/mach-goni.c b/arch/arm/mach-s5pv210/mach-goni.c >> index 31d5aa7..196e92c 100644 >> --- a/arch/arm/mach-s5pv210/mach-goni.c >> +++ b/arch/arm/mach-s5pv210/mach-goni.c >> @@ -225,6 +225,11 @@ static void __init goni_radio_init(void) >> gpio_direction_output(gpio, 1); >> } >> >> +static u8 read_chg(void) >> +{ >> + return gpio_get_value(S5PV210_GPJ0(5)); >> +} >> + >> /* TSP */ >> static struct mxt_platform_data qt602240_platform_data = { >> .x_line = 17, >> @@ -236,6 +241,7 @@ static struct mxt_platform_data qt602240_platform_data = { >> .voltage = 2800000, /* 2.8V */ >> .orient = MXT_DIAGONAL, >> .irqflags = IRQF_TRIGGER_FALLING, >> + .read_chg = &read_chg, >> }; >> >> static struct s3c2410_platform_i2c i2c2_data __initdata = { >> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c >> index 1e61387..99df3b7 100644 >> --- a/drivers/input/touchscreen/atmel_mxt_ts.c >> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c >> @@ -170,7 +170,8 @@ >> #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 */ > > Can't we really start polling before 200msecs are up? Woudl it be > possible to leave the initial wait at 65 (or maybe increase it to 100 > msecs)? > I'm afraid that on mXT1386, we need 200ms. I'll submit a version where we check the ID of the chip and adjust the delay based on that. >> +#define MXT_RESET_NOCHGREAD 400 /* msec */ >> >> #define MXT_FWRESET_TIME 175 /* msec */ >> >> @@ -792,6 +793,7 @@ 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 +830,16 @@ static int mxt_initialize(struct mxt_data *data) >> mxt_write_object(data, MXT_GEN_COMMAND, >> MXT_COMMAND_RESET, 1); >> msleep(MXT_RESET_TIME); >> + if (data->pdata->read_chg == NULL) { >> + msleep(MXT_RESET_NOCHGREAD); > > This means that without read_chg we are waiting for 600ms now... It is > eternity. Can we wait for MXT_RESET_NOCHGREAD total? > Yes, 400ms in total should be fine. >> + } else { >> + 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 >
diff --git a/arch/arm/mach-s5pv210/mach-goni.c b/arch/arm/mach-s5pv210/mach-goni.c index 31d5aa7..196e92c 100644 --- a/arch/arm/mach-s5pv210/mach-goni.c +++ b/arch/arm/mach-s5pv210/mach-goni.c @@ -225,6 +225,11 @@ static void __init goni_radio_init(void) gpio_direction_output(gpio, 1); } +static u8 read_chg(void) +{ + return gpio_get_value(S5PV210_GPJ0(5)); +} + /* TSP */ static struct mxt_platform_data qt602240_platform_data = { .x_line = 17, @@ -236,6 +241,7 @@ static struct mxt_platform_data qt602240_platform_data = { .voltage = 2800000, /* 2.8V */ .orient = MXT_DIAGONAL, .irqflags = IRQF_TRIGGER_FALLING, + .read_chg = &read_chg, }; static struct s3c2410_platform_i2c i2c2_data __initdata = { diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index 1e61387..99df3b7 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -170,7 +170,8 @@ #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_RESET_NOCHGREAD 400 /* msec */ #define MXT_FWRESET_TIME 175 /* msec */ @@ -792,6 +793,7 @@ 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 +830,16 @@ static int mxt_initialize(struct mxt_data *data) mxt_write_object(data, MXT_GEN_COMMAND, MXT_COMMAND_RESET, 1); msleep(MXT_RESET_TIME); + if (data->pdata->read_chg == NULL) { + msleep(MXT_RESET_NOCHGREAD); + } else { + 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 */
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. v3: Add a check for NULL read_chg() function, and add the read_chg() to platform files using this driver (currently only mach-goni.c) 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 <iiro.valkonen@atmel.com> --- arch/arm/mach-s5pv210/mach-goni.c | 6 ++++++ drivers/input/touchscreen/atmel_mxt_ts.c | 14 +++++++++++++- include/linux/i2c/atmel_mxt_ts.h | 1 + 3 files changed, 20 insertions(+), 1 deletions(-)