From: Nick Dyer
The workaround of reading all messages until an invalid is received is a
way of forcing the CHG line high, which means that when using
edge-triggered interrupts the interrupt can be acquired.
With level-triggered interrupts the workaround is unnecessary.
Also, most recent maXTouch chips have a feature called RETRIGEN which, when
enabled, reasserts the interrupt line every cycle if there are messages
waiting. This also makes the workaround unnecessary.
Note: the RETRIGEN feature is only in some firmware versions/chips, it's
not valid simply to enable the bit.
Signed-off-by: Nick Dyer
Acked-by: Benson Leung
Acked-by: Yufeng Shen
(cherry picked from ndyer/linux/for-upstream commit
1ae4e8281e491b22442cd5acdfca1862555f8ecb)
[gdavis: Fix conflicts due to v4.6-rc7 commit eb43335c4095 ("Input:
atmel_mxt_ts - use mxt_acquire_irq in mxt_soft_reset").]
Signed-off-by: George G. Davis
[jiada: reset use_retrigen_workaround at beginning of mxt_check_retrigen()
call mxt_check_retrigen() after mxt_acquire_irq() in mxt_initialize()
replace white-spaces with tab for MXT_COMMS_RETRIGEN
Changed to check if IRQ is level type]
Signed-off-by: Jiada Wang
---
drivers/input/touchscreen/atmel_mxt_ts.c | 56 ++--
1 file changed, 53 insertions(+), 3 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c
b/drivers/input/touchscreen/atmel_mxt_ts.c
index a2189739e30f..6b71b0aff115 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -20,6 +20,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -129,6 +130,7 @@ struct t9_range {
/* MXT_SPT_COMMSCONFIG_T18 */
#define MXT_COMMS_CTRL 0
#define MXT_COMMS_CMD 1
+#define MXT_COMMS_RETRIGEN BIT(6)
/* MXT_DEBUG_DIAGNOSTIC_T37 */
#define MXT_DIAGNOSTIC_PAGEUP 0x01
@@ -308,6 +310,7 @@ struct mxt_data {
struct t7_config t7_cfg;
struct mxt_dbg dbg;
struct gpio_desc *reset_gpio;
+ bool use_retrigen_workaround;
/* Cached parameters from object table */
u16 T5_address;
@@ -318,6 +321,7 @@ struct mxt_data {
u16 T71_address;
u8 T9_reportid_min;
u8 T9_reportid_max;
+ u16 T18_address;
u8 T19_reportid;
u16 T44_address;
u8 T100_reportid_min;
@@ -1190,9 +1194,11 @@ static int mxt_acquire_irq(struct mxt_data *data)
enable_irq(data->irq);
- error = mxt_process_messages_until_invalid(data);
- if (error)
- return error;
+ if (data->use_retrigen_workaround) {
+ error = mxt_process_messages_until_invalid(data);
+ if (error)
+ return error;
+ }
return 0;
}
@@ -1282,6 +1288,38 @@ static u32 mxt_calculate_crc(u8 *base, off_t start_off,
off_t end_off)
return crc;
}
+static int mxt_check_retrigen(struct mxt_data *data)
+{
+ struct i2c_client *client = data->client;
+ int error;
+ int val;
+ struct irq_data *irqd;
+
+ data->use_retrigen_workaround = false;
+
+ irqd = irq_get_irq_data(data->irq);
+ if (!irqd)
+ return -EINVAL;
+
+ if (irqd_is_level_type(irqd))
+ return 0;
+
+ if (data->T18_address) {
+ error = __mxt_read_reg(client,
+ data->T18_address + MXT_COMMS_CTRL,
+ 1, );
+ if (error)
+ return error;
+
+ if (val & MXT_COMMS_RETRIGEN)
+ return 0;
+ }
+
+ dev_warn(>dev, "Enabling RETRIGEN workaround\n");
+ data->use_retrigen_workaround = true;
+ return 0;
+}
+
static int mxt_prepare_cfg_mem(struct mxt_data *data, struct mxt_cfg *cfg)
{
struct device *dev = >client->dev;
@@ -1561,6 +1599,10 @@ static int mxt_update_cfg(struct mxt_data *data, const
struct firmware *fw)
mxt_update_crc(data, MXT_COMMAND_BACKUPNV, MXT_BACKUP_VALUE);
+ ret = mxt_check_retrigen(data);
+ if (ret)
+ goto release_mem;
+
ret = mxt_soft_reset(data);
if (ret)
goto release_mem;
@@ -1604,6 +1646,7 @@ static void mxt_free_object_table(struct mxt_data *data)
data->T71_address = 0;
data->T9_reportid_min = 0;
data->T9_reportid_max = 0;
+ data->T18_address = 0;
data->T19_reportid = 0;
data->T44_address = 0;
data->T100_reportid_min = 0;
@@ -1678,6 +1721,9 @@ static int mxt_parse_object_table(struct mxt_data *data,
object->num_report_ids - 1;
data->num_touchids = object->num_report_ids;
break;
+ case MXT_SPT_COMMSCONFIG_T18:
+ data->T18_address = object->start_address;
+ break;
