Input: iqs269a - configure device with a single block write

Unless it is being done as part of servicing a soft reset interrupt,
configuring channels on-the-fly (as is the case when writing to the
ati_trigger attribute) may cause GPIO3 (which reflects the state of
touch for a selected channel) to be inadvertently asserted.

To solve this problem, follow the vendor's recommendation and write
all channel configuration as well as the REDO_ATI register field as
part of a single block write. This ensures the device has been told
to re-calibrate itself following an I2C stop condition, after which
sensing resumes and GPIO3 may be asserted.

Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/Y7Rs8GyV7g0nF5Yy@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/misc/iqs269a.c b/drivers/input/misc/iqs269a.c
index e299b22b6fdbd4d0421b9fdef1fef04226553c07..07eda05d783ef47db99ac65e8926d0b00fe60366 100644 (file)
--- a/drivers/input/misc/iqs269a.c
+++ b/drivers/input/misc/iqs269a.c
@@ -96,8 +96,6 @@
 #define IQS269_MISC_B_TRACKING_UI_ENABLE       BIT(4)
 #define IQS269_MISC_B_FILT_STR_SLIDER          GENMASK(1, 0)
 
-#define IQS269_CHx_SETTINGS                    0x8C
-
 #define IQS269_CHx_ENG_A_MEAS_CAP_SIZE         BIT(15)
 #define IQS269_CHx_ENG_A_RX_GND_INACTIVE       BIT(13)
 #define IQS269_CHx_ENG_A_LOCAL_CAP_SIZE                BIT(12)
@@ -245,6 +243,18 @@ struct iqs269_ver_info {
        u8 padding;
 } __packed;
 
+struct iqs269_ch_reg {
+       u8 rx_enable;
+       u8 tx_enable;
+       __be16 engine_a;
+       __be16 engine_b;
+       __be16 ati_comp;
+       u8 thresh[3];
+       u8 hyst;
+       u8 assoc_select;
+       u8 assoc_weight;
+} __packed;
+
 struct iqs269_sys_reg {
        __be16 general;
        u8 active;
@@ -266,18 +276,7 @@ struct iqs269_sys_reg {
        u8 timeout_swipe;
        u8 thresh_swipe;
        u8 redo_ati;
-} __packed;
-
-struct iqs269_ch_reg {
-       u8 rx_enable;
-       u8 tx_enable;
-       __be16 engine_a;
-       __be16 engine_b;
-       __be16 ati_comp;
-       u8 thresh[3];
-       u8 hyst;
-       u8 assoc_select;
-       u8 assoc_weight;
+       struct iqs269_ch_reg ch_reg[IQS269_NUM_CH];
 } __packed;
 
 struct iqs269_flags {
@@ -292,7 +291,6 @@ struct iqs269_private {
        struct regmap *regmap;
        struct mutex lock;
        struct iqs269_switch_desc switches[ARRAY_SIZE(iqs269_events)];
-       struct iqs269_ch_reg ch_reg[IQS269_NUM_CH];
        struct iqs269_sys_reg sys_reg;
        struct input_dev *keypad;
        struct input_dev *slider[IQS269_NUM_SL];
@@ -307,6 +305,7 @@ struct iqs269_private {
 static int iqs269_ati_mode_set(struct iqs269_private *iqs269,
                               unsigned int ch_num, unsigned int mode)
 {
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        u16 engine_a;
 
        if (ch_num >= IQS269_NUM_CH)
@@ -317,12 +316,12 @@ static int iqs269_ati_mode_set(struct iqs269_private *iqs269,
 
        mutex_lock(&iqs269->lock);
 
-       engine_a = be16_to_cpu(iqs269->ch_reg[ch_num].engine_a);
+       engine_a = be16_to_cpu(ch_reg[ch_num].engine_a);
 
        engine_a &= ~IQS269_CHx_ENG_A_ATI_MODE_MASK;
        engine_a |= (mode << IQS269_CHx_ENG_A_ATI_MODE_SHIFT);
 
-       iqs269->ch_reg[ch_num].engine_a = cpu_to_be16(engine_a);
+       ch_reg[ch_num].engine_a = cpu_to_be16(engine_a);
        iqs269->ati_current = false;
 
        mutex_unlock(&iqs269->lock);
@@ -333,13 +332,14 @@ static int iqs269_ati_mode_set(struct iqs269_private *iqs269,
 static int iqs269_ati_mode_get(struct iqs269_private *iqs269,
                               unsigned int ch_num, unsigned int *mode)
 {
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        u16 engine_a;
 
        if (ch_num >= IQS269_NUM_CH)
                return -EINVAL;
 
        mutex_lock(&iqs269->lock);
-       engine_a = be16_to_cpu(iqs269->ch_reg[ch_num].engine_a);
+       engine_a = be16_to_cpu(ch_reg[ch_num].engine_a);
        mutex_unlock(&iqs269->lock);
 
        engine_a &= IQS269_CHx_ENG_A_ATI_MODE_MASK;
@@ -351,6 +351,7 @@ static int iqs269_ati_mode_get(struct iqs269_private *iqs269,
 static int iqs269_ati_base_set(struct iqs269_private *iqs269,
                               unsigned int ch_num, unsigned int base)
 {
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        u16 engine_b;
 
        if (ch_num >= IQS269_NUM_CH)
@@ -379,12 +380,12 @@ static int iqs269_ati_base_set(struct iqs269_private *iqs269,
 
        mutex_lock(&iqs269->lock);
 
-       engine_b = be16_to_cpu(iqs269->ch_reg[ch_num].engine_b);
+       engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 
        engine_b &= ~IQS269_CHx_ENG_B_ATI_BASE_MASK;
        engine_b |= base;
 
-       iqs269->ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
+       ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
        iqs269->ati_current = false;
 
        mutex_unlock(&iqs269->lock);
@@ -395,13 +396,14 @@ static int iqs269_ati_base_set(struct iqs269_private *iqs269,
 static int iqs269_ati_base_get(struct iqs269_private *iqs269,
                               unsigned int ch_num, unsigned int *base)
 {
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        u16 engine_b;
 
        if (ch_num >= IQS269_NUM_CH)
                return -EINVAL;
 
        mutex_lock(&iqs269->lock);
-       engine_b = be16_to_cpu(iqs269->ch_reg[ch_num].engine_b);
+       engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
        mutex_unlock(&iqs269->lock);
 
        switch (engine_b & IQS269_CHx_ENG_B_ATI_BASE_MASK) {
@@ -429,6 +431,7 @@ static int iqs269_ati_base_get(struct iqs269_private *iqs269,
 static int iqs269_ati_target_set(struct iqs269_private *iqs269,
                                 unsigned int ch_num, unsigned int target)
 {
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        u16 engine_b;
 
        if (ch_num >= IQS269_NUM_CH)
@@ -439,12 +442,12 @@ static int iqs269_ati_target_set(struct iqs269_private *iqs269,
 
        mutex_lock(&iqs269->lock);
 
-       engine_b = be16_to_cpu(iqs269->ch_reg[ch_num].engine_b);
+       engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 
        engine_b &= ~IQS269_CHx_ENG_B_ATI_TARGET_MASK;
        engine_b |= target / 32;
 
-       iqs269->ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
+       ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
        iqs269->ati_current = false;
 
        mutex_unlock(&iqs269->lock);
@@ -455,13 +458,14 @@ static int iqs269_ati_target_set(struct iqs269_private *iqs269,
 static int iqs269_ati_target_get(struct iqs269_private *iqs269,
                                 unsigned int ch_num, unsigned int *target)
 {
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        u16 engine_b;
 
        if (ch_num >= IQS269_NUM_CH)
                return -EINVAL;
 
        mutex_lock(&iqs269->lock);
-       engine_b = be16_to_cpu(iqs269->ch_reg[ch_num].engine_b);
+       engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
        mutex_unlock(&iqs269->lock);
 
        *target = (engine_b & IQS269_CHx_ENG_B_ATI_TARGET_MASK) * 32;
@@ -531,13 +535,7 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
        if (fwnode_property_present(ch_node, "azoteq,slider1-select"))
                iqs269->sys_reg.slider_select[1] |= BIT(reg);
 
-       ch_reg = &iqs269->ch_reg[reg];
-
-       error = regmap_raw_read(iqs269->regmap,
-                               IQS269_CHx_SETTINGS + reg * sizeof(*ch_reg) / 2,
-                               ch_reg, sizeof(*ch_reg));
-       if (error)
-               return error;
+       ch_reg = &iqs269->sys_reg.ch_reg[reg];
 
        error = iqs269_parse_mask(ch_node, "azoteq,rx-enable",
                                  &ch_reg->rx_enable);
@@ -1042,10 +1040,8 @@ static int iqs269_parse_prop(struct iqs269_private *iqs269)
 
 static int iqs269_dev_init(struct iqs269_private *iqs269)
 {
-       struct iqs269_sys_reg *sys_reg = &iqs269->sys_reg;
-       struct iqs269_ch_reg *ch_reg;
        unsigned int val;
-       int error, i;
+       int error;
 
        mutex_lock(&iqs269->lock);
 
@@ -1055,27 +1051,8 @@ static int iqs269_dev_init(struct iqs269_private *iqs269)
        if (error)
                goto err_mutex;
 
-       for (i = 0; i < IQS269_NUM_CH; i++) {
-               if (!(sys_reg->active & BIT(i)))
-                       continue;
-
-               ch_reg = &iqs269->ch_reg[i];
-
-               error = regmap_raw_write(iqs269->regmap,
-                                        IQS269_CHx_SETTINGS + i *
-                                        sizeof(*ch_reg) / 2, ch_reg,
-                                        sizeof(*ch_reg));
-               if (error)
-                       goto err_mutex;
-       }
-
-       /*
-        * The REDO-ATI and ATI channel selection fields must be written in the
-        * same block write, so every field between registers 0x80 through 0x8B
-        * (inclusive) must be written as well.
-        */
-       error = regmap_raw_write(iqs269->regmap, IQS269_SYS_SETTINGS, sys_reg,
-                                sizeof(*sys_reg));
+       error = regmap_raw_write(iqs269->regmap, IQS269_SYS_SETTINGS,
+                                &iqs269->sys_reg, sizeof(iqs269->sys_reg));
        if (error)
                goto err_mutex;
 
@@ -1349,6 +1326,7 @@ static ssize_t hall_bin_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
 {
        struct iqs269_private *iqs269 = dev_get_drvdata(dev);
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        struct i2c_client *client = iqs269->client;
        unsigned int val;
        int error;
@@ -1363,8 +1341,8 @@ static ssize_t hall_bin_show(struct device *dev,
        if (error)
                return error;
 
-       switch (iqs269->ch_reg[IQS269_CHx_HALL_ACTIVE].rx_enable &
-               iqs269->ch_reg[IQS269_CHx_HALL_INACTIVE].rx_enable) {
+       switch (ch_reg[IQS269_CHx_HALL_ACTIVE].rx_enable &
+               ch_reg[IQS269_CHx_HALL_INACTIVE].rx_enable) {
        case IQS269_HALL_PAD_R:
                val &= IQS269_CAL_DATA_A_HALL_BIN_R_MASK;
                val >>= IQS269_CAL_DATA_A_HALL_BIN_R_SHIFT;
@@ -1444,9 +1422,10 @@ static ssize_t rx_enable_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
 {
        struct iqs269_private *iqs269 = dev_get_drvdata(dev);
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
 
        return scnprintf(buf, PAGE_SIZE, "%u\n",
-                        iqs269->ch_reg[iqs269->ch_num].rx_enable);
+                        ch_reg[iqs269->ch_num].rx_enable);
 }
 
 static ssize_t rx_enable_store(struct device *dev,
@@ -1454,6 +1433,7 @@ static ssize_t rx_enable_store(struct device *dev,
                               size_t count)
 {
        struct iqs269_private *iqs269 = dev_get_drvdata(dev);
+       struct iqs269_ch_reg *ch_reg = iqs269->sys_reg.ch_reg;
        unsigned int val;
        int error;
 
@@ -1466,7 +1446,7 @@ static ssize_t rx_enable_store(struct device *dev,
 
        mutex_lock(&iqs269->lock);
 
-       iqs269->ch_reg[iqs269->ch_num].rx_enable = val;
+       ch_reg[iqs269->ch_num].rx_enable = val;
        iqs269->ati_current = false;
 
        mutex_unlock(&iqs269->lock);