mfd: adp5585: Add support for event handling

These devices are capable of generate FIFO based events based on KEY or
GPI presses. Add support for handling these events. This is in
preparation of adding full support for keymap and gpis based events.

Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20250701-dev-adp5589-fw-v7-12-b1fcfe9e9826@analog.com
Signed-off-by: Lee Jones <lee@kernel.org>

1 files changed, 168 insertions, 8 deletions

diff --git a/drivers/mfd/adp5585.c b/drivers/mfd/adp5585.c
index ae12372bdde9..ae2448697ef4 100644
--- a/drivers/mfd/adp5585.c
+++ b/drivers/mfd/adp5585.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/array_size.h>
+#include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
@@ -165,10 +166,16 @@ static const struct regmap_config adp5589_regmap_config_template = {
 
 static const struct adp5585_regs adp5585_regs = {
 	.ext_cfg = ADP5585_PIN_CONFIG_C,
+	.int_en = ADP5585_INT_EN,
+	.gen_cfg = ADP5585_GENERAL_CFG,
+	.poll_ptime_cfg = ADP5585_POLL_PTIME_CFG,
 };
 
 static const struct adp5585_regs adp5589_regs = {
 	.ext_cfg = ADP5589_PIN_CONFIG_D,
+	.int_en = ADP5589_INT_EN,
+	.gen_cfg = ADP5589_GENERAL_CFG,
+	.poll_ptime_cfg = ADP5589_POLL_PTIME_CFG,
 };
 
 static struct regmap_config *adp5585_fill_variant_config(struct adp5585_dev *adp5585)
@@ -241,6 +248,146 @@ static void adp5585_osc_disable(void *data)
 	regmap_write(adp5585->regmap, ADP5585_GENERAL_CFG, 0);
 }
 
+static void adp5585_report_events(struct adp5585_dev *adp5585, int ev_cnt)
+{
+	unsigned int i;
+
+	for (i = 0; i < ev_cnt; i++) {
+		unsigned long key_val, key_press;
+		unsigned int key;
+		int ret;
+
+		ret = regmap_read(adp5585->regmap, ADP5585_FIFO_1 + i, &key);
+		if (ret)
+			return;
+
+		key_val = FIELD_GET(ADP5585_KEY_EVENT_MASK, key);
+		key_press = FIELD_GET(ADP5585_KEV_EV_PRESS_MASK, key);
+
+		blocking_notifier_call_chain(&adp5585->event_notifier, key_val, (void *)key_press);
+	}
+}
+
+static irqreturn_t adp5585_irq(int irq, void *data)
+{
+	struct adp5585_dev *adp5585 = data;
+	unsigned int status, ev_cnt;
+	int ret;
+
+	ret = regmap_read(adp5585->regmap, ADP5585_INT_STATUS, &status);
+	if (ret)
+		return IRQ_HANDLED;
+
+	if (status & ADP5585_OVRFLOW_INT)
+		dev_err_ratelimited(adp5585->dev, "Event overflow error\n");
+
+	if (!(status & ADP5585_EVENT_INT))
+		goto out_irq;
+
+	ret = regmap_read(adp5585->regmap, ADP5585_STATUS, &ev_cnt);
+	if (ret)
+		goto out_irq;
+
+	ev_cnt = FIELD_GET(ADP5585_EC_MASK, ev_cnt);
+	if (!ev_cnt)
+		goto out_irq;
+
+	adp5585_report_events(adp5585, ev_cnt);
+out_irq:
+	regmap_write(adp5585->regmap, ADP5585_INT_STATUS, status);
+	return IRQ_HANDLED;
+}
+
+static int adp5585_setup(struct adp5585_dev *adp5585)
+{
+	const struct adp5585_regs *regs = adp5585->regs;
+	unsigned int reg_val, i;
+	int ret;
+
+	/* Clear any possible event by reading all the FIFO entries */
+	for (i = 0; i < ADP5585_EV_MAX; i++) {
+		ret = regmap_read(adp5585->regmap, ADP5585_FIFO_1 + i, &reg_val);
+		if (ret)
+			return ret;
+	}
+
+	ret = regmap_write(adp5585->regmap, regs->poll_ptime_cfg, adp5585->ev_poll_time);
+	if (ret)
+		return ret;
+
+	/*
+	 * Enable the internal oscillator, as it's shared between multiple
+	 * functions.
+	 */
+	ret = regmap_write(adp5585->regmap, regs->gen_cfg,
+			   ADP5585_OSC_FREQ_500KHZ | ADP5585_INT_CFG | ADP5585_OSC_EN);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(adp5585->dev, adp5585_osc_disable, adp5585);
+}
+
+static int adp5585_parse_fw(struct adp5585_dev *adp5585)
+{
+	unsigned int prop_val;
+	int ret;
+
+	ret = device_property_read_u32(adp5585->dev, "poll-interval", &prop_val);
+	if (!ret) {
+		adp5585->ev_poll_time = prop_val / 10 - 1;
+		/*
+		 * ev_poll_time is the raw value to be written on the register and 0 to 3 are the
+		 * valid values.
+		 */
+		if (adp5585->ev_poll_time > 3)
+			return dev_err_probe(adp5585->dev, -EINVAL,
+					     "Invalid value(%u) for poll-interval\n", prop_val);
+	}
+
+	return 0;
+}
+
+static void adp5585_irq_disable(void *data)
+{
+	struct adp5585_dev *adp5585 = data;
+
+	regmap_write(adp5585->regmap, adp5585->regs->int_en, 0);
+}
+
+static int adp5585_irq_enable(struct i2c_client *i2c,
+			      struct adp5585_dev *adp5585)
+{
+	const struct adp5585_regs *regs = adp5585->regs;
+	unsigned int stat;
+	int ret;
+
+	if (i2c->irq <= 0)
+		return 0;
+
+	ret = devm_request_threaded_irq(&i2c->dev, i2c->irq, NULL, adp5585_irq,
+					IRQF_ONESHOT, i2c->name, adp5585);
+	if (ret)
+		return ret;
+
+	/*
+	 * Clear any possible outstanding interrupt before enabling them. We do that by reading
+	 * the status register and writing back the same value.
+	 */
+	ret = regmap_read(adp5585->regmap, ADP5585_INT_STATUS, &stat);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(adp5585->regmap, ADP5585_INT_STATUS, stat);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(adp5585->regmap, regs->int_en, ADP5585_OVRFLOW_IEN | ADP5585_EVENT_IEN);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(&i2c->dev, adp5585_irq_disable, adp5585);
+}
+
 static int adp5585_i2c_probe(struct i2c_client *i2c)
 {
 	struct regmap_config *regmap_config;
@@ -254,6 +401,8 @@ static int adp5585_i2c_probe(struct i2c_client *i2c)
 
 	i2c_set_clientdata(i2c, adp5585);
 	adp5585->dev = &i2c->dev;
+	adp5585->irq = i2c->irq;
+	BLOCKING_INIT_NOTIFIER_HEAD(&adp5585->event_notifier);
 
 	adp5585->variant = (enum adp5585_variant)(uintptr_t)i2c_get_match_data(i2c);
 	if (!adp5585->variant)
@@ -278,25 +427,28 @@ static int adp5585_i2c_probe(struct i2c_client *i2c)
 		return dev_err_probe(&i2c->dev, -ENODEV,
 				     "Invalid device ID 0x%02x\n", id);
 
-	/*
-	 * Enable the internal oscillator, as it's shared between multiple
-	 * functions.
-	 */
-	ret = regmap_set_bits(adp5585->regmap, ADP5585_GENERAL_CFG, ADP5585_OSC_EN);
+	ret = adp5585_parse_fw(adp5585);
 	if (ret)
 		return ret;
 
-	ret = devm_add_action_or_reset(&i2c->dev, adp5585_osc_disable, adp5585);
+	ret = adp5585_setup(adp5585);
 	if (ret)
 		return ret;
 
-	return adp5585_add_devices(adp5585);
+	ret = adp5585_add_devices(adp5585);
+	if (ret)
+		return ret;
+
+	return adp5585_irq_enable(i2c, adp5585);
 }
 
 static int adp5585_suspend(struct device *dev)
 {
 	struct adp5585_dev *adp5585 = dev_get_drvdata(dev);
 
+	if (adp5585->irq)
+		disable_irq(adp5585->irq);
+
 	regcache_cache_only(adp5585->regmap, true);
 
 	return 0;
@@ -305,11 +457,19 @@ static int adp5585_suspend(struct device *dev)
 static int adp5585_resume(struct device *dev)
 {
 	struct adp5585_dev *adp5585 = dev_get_drvdata(dev);
+	int ret;
 
 	regcache_cache_only(adp5585->regmap, false);
 	regcache_mark_dirty(adp5585->regmap);
 
-	return regcache_sync(adp5585->regmap);
+	ret = regcache_sync(adp5585->regmap);
+	if (ret)
+		return ret;
+
+	if (adp5585->irq)
+		enable_irq(adp5585->irq);
+
+	return 0;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(adp5585_pm, adp5585_suspend, adp5585_resume);