[PATCH v4 04/48] Input: atmel_mxt_ts - split large i2c transfers into blocks
From: Jiada Wang <hidden>
Date: 2019-10-29 07:20:33
Also in:
lkml
Subsystem:
atmel maxtouch driver, input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Nick Dyer, Dmitry Torokhov, Linus Torvalds
From: Nick Dyer <redacted>
On some firmware variants, the size of the info block exceeds what can
be read in a single transfer.
Signed-off-by: Nick Dyer <redacted>
(cherry picked from ndyer/linux/for-upstream commit 74c4f5277cfa403d43fafc404119dc57a08677db)
[gdavis: Forward port and fix conflicts due to v4.14.51 commit
960fe000b1d3 ("Input: atmel_mxt_ts - fix the firmware
update").]
Signed-off-by: George G. Davis <redacted>
[jiada: Change mxt_read_blks() to __mxt_read_reg(), original __mxt_read_reg() to
__mxt_read_chunk()]
Signed-off-by: Jiada Wang <redacted>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 28 +++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index ce5a069b62d4..9088b2d3266b 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c@@ -40,7 +40,7 @@ #define MXT_OBJECT_START 0x07 #define MXT_OBJECT_SIZE 6 #define MXT_INFO_CHECKSUM_SIZE 3 -#define MXT_MAX_BLOCK_WRITE 256 +#define MXT_MAX_BLOCK_WRITE 255 /* Object types */ #define MXT_DEBUG_DIAGNOSTIC_T37 37
@@ -624,8 +624,8 @@ static int mxt_send_bootloader_cmd(struct mxt_data *data, bool unlock) return 0; } -static int __mxt_read_reg(struct i2c_client *client, - u16 reg, u16 len, void *val) +static int __mxt_read_chunk(struct i2c_client *client, + u16 reg, u16 len, void *val) { struct i2c_msg xfer[2]; u8 buf[2];
@@ -659,6 +659,28 @@ static int __mxt_read_reg(struct i2c_client *client, return ret; } +static int __mxt_read_reg(struct i2c_client *client, + u16 reg, u16 len, void *buf) +{ + u16 offset = 0; + int error; + u16 size; + + while (offset < len) { + size = min(MXT_MAX_BLOCK_WRITE, len - offset); + + error = __mxt_read_chunk(client, + reg + offset, + size, buf + offset); + if (error) + return error; + + offset += size; + } + + return 0; +} + static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len, const void *val) {
--
2.17.1