[PATCH 4/6] input: iqs269a: Add support for OTP variants

Jeff LaBundy
2020-08-16T21:15:25Z

This patch adds support for each available OTP variant of the device.
The OTP configuration cannot be read over I2C, so it is derived from
a compatible string instead.

Early revisions of the D0 order code require their OTP-enabled func-
tionality to be manually restored following a soft reset; this patch
works around this erratum as well.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
---
drivers/input/misc/iqs269a.c | 94 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 91 insertions(+), 3 deletions(-)

diff --git a/drivers/input/misc/iqs269a.c b/drivers/input/misc/iqs269a.c
index 095e5d5..04947f1 100644
--- a/drivers/input/misc/iqs269a.c
+++ b/drivers/input/misc/iqs269a.c
@@ -100,6 +100,11 @@
#define IQS269_MISC_B_TRACKING_UI_ENABLE BIT(4)
#define IQS269_MISC_B_FILT_STR_SLIDER GENMASK(1, 0)

+#define IQS269_TOUCH_HOLD_SLIDER_SEL 0x89
+#define IQS269_TOUCH_HOLD_DEFAULT 0x14
+#define IQS269_TOUCH_HOLD_MS_MIN 256
+#define IQS269_TOUCH_HOLD_MS_MAX 65280
+
#define IQS269_TIMEOUT_TAP_MS_MAX 4080
#define IQS269_TIMEOUT_SWIPE_MS_MAX 4080
#define IQS269_THRESH_SWIPE_MAX 255
@@ -142,6 +147,10 @@
#define IQS269_CHx_HALL_INACTIVE 6
#define IQS269_CHx_HALL_ACTIVE 7

+#define IQS269_OTP_OPTION_DEFAULT 0x00
+#define IQS269_OTP_OPTION_TWS 0xD0
+#define IQS269_OTP_OPTION_HOLD BIT(7)
+
#define IQS269_HALL_PAD_R BIT(0)
#define IQS269_HALL_PAD_L BIT(1)
#define IQS269_HALL_PAD_INV BIT(6)
@@ -322,6 +331,7 @@ struct iqs269_private {
unsigned int keycode[ARRAY_SIZE(iqs269_events) * IQS269_NUM_CH];
unsigned int gs_code[IQS269_NUM_SL][IQS269_NUM_GESTURES];
unsigned int suspend_mode;
+ unsigned int otp_option;
unsigned int delay_mult;
unsigned int ch_num;
bool hall_enable;
@@ -333,6 +343,14 @@ static enum iqs269_slider_id iqs269_slider_type(struct iqs269_private *iqs269,
{
int i;

+ /*
+ * Slider 1 is unavailable if the touch-and-hold option is enabled via
+ * OTP. In that case, the channel selection register is repurposed for
+ * the touch-and-hold timer ceiling.
+ */
+ if (slider_num && (iqs269->otp_option & IQS269_OTP_OPTION_HOLD))
+ return IQS269_SLIDER_NONE;
+
if (!iqs269->sys_reg.slider_select[slider_num])
return IQS269_SLIDER_NONE;

@@ -567,7 +585,8 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
if (fwnode_property_present(ch_node, "azoteq,slider0-select"))
iqs269->sys_reg.slider_select[0] |= BIT(reg);

- if (fwnode_property_present(ch_node, "azoteq,slider1-select"))
+ if (fwnode_property_present(ch_node, "azoteq,slider1-select") &&
+ !(iqs269->otp_option & IQS269_OTP_OPTION_HOLD))
iqs269->sys_reg.slider_select[1] |= BIT(reg);

ch_reg = &iqs269->ch_reg[reg];
@@ -999,7 +1018,43 @@ static int iqs269_parse_prop(struct iqs269_private *iqs269)
sys_reg->blocking = 0;

sys_reg->slider_select[0] = 0;
- sys_reg->slider_select[1] = 0;
+
+ /*
+ * If configured via OTP to do so, the device asserts a pulse on the
+ * GPIO4 pin for approximately 60 ms once a selected channel is held
+ * in a state of touch for a configurable length of time.
+ *
+ * In that case, the register used for slider 1 channel selection is
+ * repurposed for the touch-and-hold timer ceiling.
+ */
+ if (iqs269->otp_option & IQS269_OTP_OPTION_HOLD) {
+ if (!device_property_read_u32(&client->dev,
+ "azoteq,touch-hold-ms", &val)) {
+ if (val < IQS269_TOUCH_HOLD_MS_MIN ||
+ val > IQS269_TOUCH_HOLD_MS_MAX) {
+ dev_err(&client->dev,
+ "Invalid touch-and-hold ceiling: %u\n",
+ val);
+ return -EINVAL;
+ }
+
+ sys_reg->slider_select[1] = val / 256;
+ } else if (iqs269->ver_info.fw_num < IQS269_VER_INFO_FW_NUM_3) {
+ /*
+ * The default touch-and-hold timer ceiling initially
+ * read from early revisions of silicon is invalid if
+ * the device experienced a soft reset between power-
+ * on and the read operation.
+ *
+ * To protect against this case, explicitly cache the
+ * default value so that it is restored each time the
+ * device is re-initialized.
+ */
+ sys_reg->slider_select[1] = IQS269_TOUCH_HOLD_DEFAULT;
+ }
+ } else {
+ sys_reg->slider_select[1] = 0;
+ }

sys_reg->event_mask = ~((u8)IQS269_EVENT_MASK_SYS);

@@ -1140,6 +1195,12 @@ static int iqs269_parse_prop(struct iqs269_private *iqs269)
return 0;
}

+static const struct reg_sequence iqs269_tws_init[] = {
+ { IQS269_TOUCH_HOLD_SLIDER_SEL, IQS269_TOUCH_HOLD_DEFAULT },
+ { 0xF0, 0x580F },
+ { 0xF0, 0x59EF },
+};
+
static int iqs269_dev_init(struct iqs269_private *iqs269)
{
struct iqs269_sys_reg *sys_reg = &iqs269->sys_reg;
@@ -1149,6 +1210,18 @@ static int iqs269_dev_init(struct iqs269_private *iqs269)

mutex_lock(&iqs269->lock);

+ /*
+ * Early revisions of silicon require the following workaround in order
+ * to restore any OTP-enabled functionality after a soft reset.
+ */
+ if (iqs269->otp_option == IQS269_OTP_OPTION_TWS &&
+ iqs269->ver_info.fw_num < IQS269_VER_INFO_FW_NUM_3) {
+ error = regmap_multi_reg_write(iqs269->regmap, iqs269_tws_init,
+ ARRAY_SIZE(iqs269_tws_init));
+ if (error)
+ goto err_mutex;
+ }
+
error = regmap_update_bits(iqs269->regmap, IQS269_HALL_UI,
IQS269_HALL_UI_ENABLE,
iqs269->hall_enable ? ~0 : 0);
@@ -1807,6 +1880,10 @@ static int iqs269_probe(struct i2c_client *client)
i2c_set_clientdata(client, iqs269);
iqs269->client = client;

+ if (client->dev.of_node)
+ iqs269->otp_option = (uintptr_t)
+ of_device_get_match_data(&client->dev);
+
iqs269->regmap = devm_regmap_init_i2c(client, &iqs269_regmap_config);
if (IS_ERR(iqs269->regmap)) {
error = PTR_ERR(iqs269->regmap);
@@ -1967,7 +2044,18 @@ static int __maybe_unused iqs269_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(iqs269_pm, iqs269_suspend, iqs269_resume);

static const struct of_device_id iqs269_of_match[] = {
- { .compatible = "azoteq,iqs269a" },
+ {
+ .compatible = "azoteq,iqs269a",
+ .data = (void *)IQS269_OTP_OPTION_DEFAULT,
+ },
+ {
+ .compatible = "azoteq,iqs269a-00",
+ .data = (void *)IQS269_OTP_OPTION_DEFAULT,
+ },
+ {
+ .compatible = "azoteq,iqs269a-d0",
+ .data = (void *)IQS269_OTP_OPTION_TWS,
+ },
{ }
};
MODULE_DEVICE_TABLE(of, iqs269_of_match);
--
2.7.4