Re: [PATCH v4 06/10] regmap: irq: Add support for chips without separate IRQ status

On Fri, Feb 14, 2025 at 12:49:56PM +0100, Mathieu Dubois-Briand wrote:

Some GPIO chips allow to rise an IRQ on GPIO level changes but do not
provide an IRQ status for each separate line: only the current gpio
level can be retrieved.

Add support for these chips, emulating IRQ status by comparing GPIO
levels with the levels during the previous interrupt.

Thanks, this will help to convert more drivers to regmap
(e.g., gpio-pca953x that seems use similar approach).

...

+static irqreturn_t regmap_irq_thread(int irq, void *d)
+{
+	struct regmap_irq_chip_data *data = d;
+	const struct regmap_irq_chip *chip = data->chip;
+	struct regmap *map = data->map;
+	int ret, i;

	unsigned int i;
?

+	bool handled = false;
+	u32 reg;
+
+	if (chip->handle_pre_irq)
+		chip->handle_pre_irq(chip->irq_drv_data);
+
+	if (chip->runtime_pm) {
+		ret = pm_runtime_get_sync(map->dev);
+		if (ret < 0) {

+			dev_err(map->dev, "IRQ thread failed to resume: %d\n",
+				ret);

Can be one line.

+			goto exit;
+		}
+	}
+
+	ret = read_irq_data(data);
+	if (ret < 0)
+		goto exit;
+
+	if (chip->status_is_level) {
+		for (i = 0; i < data->chip->num_regs; i++) {
+			unsigned int val = data->status_buf[i];
+
+			data->status_buf[i] ^= data->prev_status_buf[i];
+			data->prev_status_buf[i] = val;
+		}
+	}

...

+		for (i = 0; i < d->chip->num_regs; i++)
+			d->prev_status_buf[i] = d->status_buf[i];

Hmm... Wouldn't memcpy() suffice?
But okay, this seems to be not a hot path and the intention is clear.

-- 
With Best Regards,
Andy Shevchenko