From 74d905d2d38ad00246e1f22c6ccad7ebb5731839 Mon Sep 17 00:00:00 2001 From: Nick Dyer Date: Tue, 28 Jul 2020 18:25:29 -0700 Subject: [PATCH] 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: 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 Link: https://lore.kernel.org/r/20200727151637.23810-1-jiada_wang@mentor.com Signed-off-by: Dmitry Torokhov --- 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, &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);