Input: atmel_mxt_ts - Make wait-after-reset period compatible with all chips

PATCH Superseded Iiro Valkonen 2 participants 3 messages Jul 6, 2011 – Jul 26, 2011

Subsystems (7)

Arm (32-bit) Arm sub-architectures HID Arm Samsung Exynos +3 more subsystems

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Iiro Valkonen

author

2011-07-06 12:13 UTC #0 lore raw

PATCH v3 1/3 Input: atmel_mxt_ts - Make wait-after-reset period compatible with all chips

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 <[email protected]>

---
 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(-)

arch/arm/mach-s5pv210/mach-goni.c +6 -0

index 31d5aa7..196e92c 100644
@@ -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 = {

drivers/input/touchscreen/atmel_mxt_ts.c +13 -1

index 1e61387..99df3b7 100644
@@ -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);

include/linux/i2c/atmel_mxt_ts.h +1 -0

index f027f7a..ef59c22 100644
@@ -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 */

Signature · 1 line

1.7.0.4

Dmitry Torokhov

maintainer

2011-07-07 14:43 UTC #1 lore raw

Quoted 45 lines · Iiro Valkonen

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 <[email protected]>
---
 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(-)
arch/arm/mach-s5pv210/mach-goni.c +6 -0
index 31d5aa7..196e92c 100644
@@ -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 = {
drivers/input/touchscreen/atmel_mxt_ts.c +0 -0
index 1e61387..99df3b7 100644

drivers/input/touchscreen/atmel_mxt_ts.c line 173

Quoted 5 lines

drivers/input/touchscreen/atmel_mxt_ts.c +1 -1

@@ -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)?

Quoted 13 lines

drivers/input/touchscreen/atmel_mxt_ts.c +2 -0

+#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);

drivers/input/touchscreen/atmel_mxt_ts.c static int mxt_initialize(struct mxt_data *data) · line 834

Quoted 5 lines

drivers/input/touchscreen/atmel_mxt_ts.c +2 -0

@@ -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?

Quoted 25 lines

drivers/input/touchscreen/atmel_mxt_ts.c +8 -0

+	} 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);

include/linux/i2c/atmel_mxt_ts.h +1 -0

index f027f7a..ef59c22 100644
@@ -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 */

Signature · 1 line

1.7.0.4

Signature · 1 line

Dmitry

Iiro Valkonen

author

2011-07-26 16:20 UTC #2 lore raw

Quoted 40 lines · Dmitry Torokhov

Quoted 39 lines · Iiro Valkonen
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 <[email protected]>
---
 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(-)
arch/arm/mach-s5pv210/mach-goni.c +6 -0
index 31d5aa7..196e92c 100644
@@ -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,
 };
 

Quoted 16 lines

drivers/input/touchscreen/atmel_mxt_ts.c line 173
Quoted 11 lines
arch/arm/mach-s5pv210/mach-goni.c +0 -0
 static struct s3c2410_platform_i2c i2c2_data __initdata = {
drivers/input/touchscreen/atmel_mxt_ts.c +1 -1
index 1e61387..99df3b7 100644
@@ -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.

Quoted 11 lines

drivers/input/touchscreen/atmel_mxt_ts.c +2 -0

+#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;

Quoted 11 lines

drivers/input/touchscreen/atmel_mxt_ts.c static int mxt_initialize(struct mxt_data *data) · line 834
Quoted 7 lines
drivers/input/touchscreen/atmel_mxt_ts.c +2 -0
 	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.

Quoted 26 lines

Quoted 25 lines

drivers/input/touchscreen/atmel_mxt_ts.c +8 -0

+	} 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);

include/linux/i2c/atmel_mxt_ts.h +1 -0

index f027f7a..ef59c22 100644
@@ -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 */

Signature · 1 line

1.7.0.4

Signature · 1 line

Iiro