From 02e550d5b706f034d24e7e46234eb1982f05a137 Mon Sep 17 00:00:00 2001 From: Jeff LaBundy Date: Sun, 17 Jan 2021 21:57:07 -0600 Subject: mfd: iqs62x: Do not poll during ATI After loading firmware, the driver triggers ATI (calibration) with the newly loaded register configuration in place. Next, the driver polls a register field to ensure ATI completed in a timely fashion and that the device is ready to sense. However, communicating with the device over I2C while ATI is under- way may induce noise in the device and cause ATI to fail. As such, the vendor recommends not to poll the device during ATI. To solve this problem, let the device naturally signal to the host that ATI is complete by way of an interrupt. A completion prevents the sub-devices from being registered until this happens. The former logic that scaled ATI timeout and filter settling delay is not carried forward with the new implementation, as it produces overly conservative delays at lower clock rates. Instead, a single pair of delays that covers all cases is used. Signed-off-by: Jeff LaBundy Signed-off-by: Lee Jones --- drivers/mfd/iqs62x.c | 125 ++++++++++++++++++++++++++++----------------------- 1 file changed, 69 insertions(+), 56 deletions(-) (limited to 'drivers/mfd/iqs62x.c') diff --git a/drivers/mfd/iqs62x.c b/drivers/mfd/iqs62x.c index 07c972531715..9b5c389ca2c3 100644 --- a/drivers/mfd/iqs62x.c +++ b/drivers/mfd/iqs62x.c @@ -36,7 +36,6 @@ #define IQS62X_PROD_NUM 0x00 #define IQS62X_SYS_FLAGS 0x10 -#define IQS62X_SYS_FLAGS_IN_ATI BIT(2) #define IQS620_HALL_FLAGS 0x16 #define IQS621_HALL_FLAGS 0x19 @@ -60,6 +59,7 @@ #define IQS62X_SYS_SETTINGS_ACK_RESET BIT(6) #define IQS62X_SYS_SETTINGS_EVENT_MODE BIT(5) #define IQS62X_SYS_SETTINGS_CLK_DIV BIT(4) +#define IQS62X_SYS_SETTINGS_COMM_ATI BIT(3) #define IQS62X_SYS_SETTINGS_REDO_ATI BIT(1) #define IQS62X_PWR_SETTINGS 0xD2 @@ -81,9 +81,7 @@ #define IQS62X_FW_REC_TYPE_MASK 3 #define IQS62X_FW_REC_TYPE_DATA 4 -#define IQS62X_ATI_POLL_SLEEP_US 10000 -#define IQS62X_ATI_POLL_TIMEOUT_US 500000 -#define IQS62X_ATI_STABLE_DELAY_MS 150 +#define IQS62X_FILT_SETTLE_MS 250 struct iqs62x_fw_rec { u8 type; @@ -111,7 +109,6 @@ static int iqs62x_dev_init(struct iqs62x_core *iqs62x) struct iqs62x_fw_blk *fw_blk; unsigned int val; int ret; - u8 clk_div = 1; list_for_each_entry(fw_blk, &iqs62x->fw_blk_head, list) { if (fw_blk->mask) @@ -181,28 +178,32 @@ static int iqs62x_dev_init(struct iqs62x_core *iqs62x) return ret; } - ret = regmap_read(iqs62x->regmap, IQS62X_SYS_SETTINGS, &val); - if (ret) - return ret; - - if (val & IQS62X_SYS_SETTINGS_CLK_DIV) - clk_div = iqs62x->dev_desc->clk_div; - - ret = regmap_write(iqs62x->regmap, IQS62X_SYS_SETTINGS, val | - IQS62X_SYS_SETTINGS_ACK_RESET | - IQS62X_SYS_SETTINGS_EVENT_MODE | - IQS62X_SYS_SETTINGS_REDO_ATI); - if (ret) - return ret; - - ret = regmap_read_poll_timeout(iqs62x->regmap, IQS62X_SYS_FLAGS, val, - !(val & IQS62X_SYS_FLAGS_IN_ATI), - IQS62X_ATI_POLL_SLEEP_US, - IQS62X_ATI_POLL_TIMEOUT_US * clk_div); + /* + * Place the device in streaming mode at first so as not to miss the + * limited number of interrupts that would otherwise occur after ATI + * completes. The device is subsequently placed in event mode by the + * interrupt handler. + * + * In the meantime, mask interrupts during ATI to prevent the device + * from soliciting I2C traffic until the noise-sensitive ATI process + * is complete. + */ + ret = regmap_update_bits(iqs62x->regmap, IQS62X_SYS_SETTINGS, + IQS62X_SYS_SETTINGS_ACK_RESET | + IQS62X_SYS_SETTINGS_EVENT_MODE | + IQS62X_SYS_SETTINGS_COMM_ATI | + IQS62X_SYS_SETTINGS_REDO_ATI, + IQS62X_SYS_SETTINGS_ACK_RESET | + IQS62X_SYS_SETTINGS_REDO_ATI); if (ret) return ret; - msleep(IQS62X_ATI_STABLE_DELAY_MS * clk_div); + /* + * The following delay gives the device time to deassert its RDY output + * in case a communication window was open while the REDO_ATI field was + * written. This prevents an interrupt from being serviced prematurely. + */ + usleep_range(5000, 5100); return 0; } @@ -433,6 +434,11 @@ const struct iqs62x_event_desc iqs62x_events[IQS62X_NUM_EVENTS] = { .mask = BIT(7), .val = BIT(7), }, + [IQS62X_EVENT_SYS_ATI] = { + .reg = IQS62X_EVENT_SYS, + .mask = BIT(2), + .val = BIT(2), + }, }; EXPORT_SYMBOL_GPL(iqs62x_events); @@ -521,12 +527,39 @@ static irqreturn_t iqs62x_irq(int irq, void *context) "Failed to re-initialize device: %d\n", ret); return IRQ_NONE; } + + iqs62x->event_cache |= BIT(IQS62X_EVENT_SYS_RESET); + reinit_completion(&iqs62x->ati_done); + } else if (event_flags & BIT(IQS62X_EVENT_SYS_ATI)) { + iqs62x->event_cache |= BIT(IQS62X_EVENT_SYS_ATI); + reinit_completion(&iqs62x->ati_done); + } else if (!completion_done(&iqs62x->ati_done)) { + ret = regmap_update_bits(iqs62x->regmap, IQS62X_SYS_SETTINGS, + IQS62X_SYS_SETTINGS_EVENT_MODE, 0xFF); + if (ret) { + dev_err(&client->dev, + "Failed to enable event mode: %d\n", ret); + return IRQ_NONE; + } + + msleep(IQS62X_FILT_SETTLE_MS); + complete_all(&iqs62x->ati_done); } - ret = blocking_notifier_call_chain(&iqs62x->nh, event_flags, - &event_data); - if (ret & NOTIFY_STOP_MASK) - return IRQ_NONE; + /* + * Reset and ATI events are not broadcast to the sub-device drivers + * until ATI has completed. Any other events that may have occurred + * during ATI are ignored. + */ + if (completion_done(&iqs62x->ati_done)) { + event_flags |= iqs62x->event_cache; + ret = blocking_notifier_call_chain(&iqs62x->nh, event_flags, + &event_data); + if (ret & NOTIFY_STOP_MASK) + return IRQ_NONE; + + iqs62x->event_cache = 0; + } /* * Once the communication window is closed, a small delay is added to @@ -567,6 +600,12 @@ static void iqs62x_firmware_load(const struct firmware *fw, void *context) goto err_out; } + if (!wait_for_completion_timeout(&iqs62x->ati_done, + msecs_to_jiffies(2000))) { + dev_err(&client->dev, "Failed to complete ATI\n"); + goto err_out; + } + ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE, iqs62x->dev_desc->sub_devs, iqs62x->dev_desc->num_sub_devs, @@ -748,22 +787,17 @@ static const struct iqs62x_dev_desc iqs62x_devs[] = { .dev_name = "iqs620at", .sub_devs = iqs620at_sub_devs, .num_sub_devs = ARRAY_SIZE(iqs620at_sub_devs), - .prod_num = IQS620_PROD_NUM, .sw_num = 0x08, .cal_regs = iqs620at_cal_regs, .num_cal_regs = ARRAY_SIZE(iqs620at_cal_regs), - .prox_mask = BIT(0), .sar_mask = BIT(1) | BIT(7), .hall_mask = BIT(2), .hyst_mask = BIT(3), .temp_mask = BIT(4), - .prox_settings = IQS620_PROX_SETTINGS_4, .hall_flags = IQS620_HALL_FLAGS, - - .clk_div = 4, .fw_name = "iqs620a.bin", .event_regs = &iqs620a_event_regs[IQS62X_UI_PROX], }, @@ -771,20 +805,15 @@ static const struct iqs62x_dev_desc iqs62x_devs[] = { .dev_name = "iqs620a", .sub_devs = iqs620a_sub_devs, .num_sub_devs = ARRAY_SIZE(iqs620a_sub_devs), - .prod_num = IQS620_PROD_NUM, .sw_num = 0x08, - .prox_mask = BIT(0), .sar_mask = BIT(1) | BIT(7), .hall_mask = BIT(2), .hyst_mask = BIT(3), .temp_mask = BIT(4), - .prox_settings = IQS620_PROX_SETTINGS_4, .hall_flags = IQS620_HALL_FLAGS, - - .clk_div = 4, .fw_name = "iqs620a.bin", .event_regs = &iqs620a_event_regs[IQS62X_UI_PROX], }, @@ -792,23 +821,18 @@ static const struct iqs62x_dev_desc iqs62x_devs[] = { .dev_name = "iqs621", .sub_devs = iqs621_sub_devs, .num_sub_devs = ARRAY_SIZE(iqs621_sub_devs), - .prod_num = IQS621_PROD_NUM, .sw_num = 0x09, .cal_regs = iqs621_cal_regs, .num_cal_regs = ARRAY_SIZE(iqs621_cal_regs), - .prox_mask = BIT(0), .hall_mask = BIT(1), .als_mask = BIT(2), .hyst_mask = BIT(3), .temp_mask = BIT(4), - .als_flags = IQS621_ALS_FLAGS, .hall_flags = IQS621_HALL_FLAGS, .hyst_shift = 5, - - .clk_div = 2, .fw_name = "iqs621.bin", .event_regs = &iqs621_event_regs[IQS62X_UI_PROX], }, @@ -816,21 +840,16 @@ static const struct iqs62x_dev_desc iqs62x_devs[] = { .dev_name = "iqs622", .sub_devs = iqs622_sub_devs, .num_sub_devs = ARRAY_SIZE(iqs622_sub_devs), - .prod_num = IQS622_PROD_NUM, .sw_num = 0x06, - .prox_mask = BIT(0), .sar_mask = BIT(1), .hall_mask = BIT(2), .als_mask = BIT(3), .ir_mask = BIT(4), - .prox_settings = IQS622_PROX_SETTINGS_4, .als_flags = IQS622_ALS_FLAGS, .hall_flags = IQS622_HALL_FLAGS, - - .clk_div = 2, .fw_name = "iqs622.bin", .event_regs = &iqs622_event_regs[IQS62X_UI_PROX], }, @@ -838,14 +857,10 @@ static const struct iqs62x_dev_desc iqs62x_devs[] = { .dev_name = "iqs624", .sub_devs = iqs624_sub_devs, .num_sub_devs = ARRAY_SIZE(iqs624_sub_devs), - .prod_num = IQS624_PROD_NUM, .sw_num = 0x0B, - .interval = IQS624_INTERVAL_NUM, .interval_div = 3, - - .clk_div = 2, .fw_name = "iqs624.bin", .event_regs = &iqs624_event_regs[IQS62X_UI_PROX], }, @@ -853,14 +868,10 @@ static const struct iqs62x_dev_desc iqs62x_devs[] = { .dev_name = "iqs625", .sub_devs = iqs625_sub_devs, .num_sub_devs = ARRAY_SIZE(iqs625_sub_devs), - .prod_num = IQS625_PROD_NUM, .sw_num = 0x0B, - .interval = IQS625_INTERVAL_NUM, .interval_div = 10, - - .clk_div = 2, .fw_name = "iqs625.bin", .event_regs = &iqs625_event_regs[IQS62X_UI_PROX], }, @@ -890,6 +901,8 @@ static int iqs62x_probe(struct i2c_client *client) BLOCKING_INIT_NOTIFIER_HEAD(&iqs62x->nh); INIT_LIST_HEAD(&iqs62x->fw_blk_head); + + init_completion(&iqs62x->ati_done); init_completion(&iqs62x->fw_done); iqs62x->regmap = devm_regmap_init_i2c(client, &iqs62x_regmap_config); -- cgit v1.2.3