Commit 74d905d2 authored by Nick Dyer's avatar Nick Dyer Committed by Dmitry Torokhov
Browse files

Input: atmel_mxt_ts - only read messages in mxt_acquire_irq() when necessary 



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: default avatarNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: default avatarBenson Leung <bleung@chromium.org>
Acked-by: default avatarYufeng Shen <miletus@chromium.org>
(cherry picked from ndyer/linux/for-upstream commit 1ae4e8281e491b22442cd5acdfca1862555f8ecb)
[gdavis: Fix conflicts due to v4.6-rc7 commit eb43335c ("Input:
	 atmel_mxt_ts - use mxt_acquire_irq in mxt_soft_reset").]
Signed-off-by: default avatarGeorge G. Davis <george_davis@mentor.com>
[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: default avatarJiada Wang <jiada_wang@mentor.com>
Link: https://lore.kernel.org/r/20200727151637.23810-1-jiada_wang@mentor.com


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent bbca4d34

drivers/input/touchscreen/atmel_mxt_ts.c

+53 −3
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/i2c.h>

#include <linux/input/mt.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/of.h>

#include <linux/property.h>

#include <linux/slab.h>
@@ -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);



	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, &val);

		if (error)

			return error;



		if (val & MXT_COMMS_RETRIGEN)

			return 0;

	}



	dev_warn(&client->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 = &data->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;

		case MXT_SPT_MESSAGECOUNT_T44:

			data->T44_address = object->start_address;

			break;
@@ -2141,6 +2187,10 @@ static int mxt_initialize(struct mxt_data *data) 
	if (error)

		return error;



	error = mxt_check_retrigen(data);

	if (error)

		return error;



	error = request_firmware_nowait(THIS_MODULE, true, MXT_CFG_NAME,

					&client->dev, GFP_KERNEL, data,

					mxt_config_cb);

CRA Git | Maintained and supported by SUSTech CRA and CCSE