[alsa-devel] [RFT][PATCH v2] gpiolib: acpi: Introduce ACPI_GPIO_QUIRK_ONLY_GPIOIO

[Andy Shevchenko]

New quirk enforces search for GPIO based on its type,
i.e. iterate over GpioIo resources only.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
---

- it was sent few weeks ago to Hans for testing, but better to re-test
- it's supposed to go via ASoC subsystem due to recent changes made for
  sound driver

v2:
- Expand explanation why this quirk might be needed (Mika)

 drivers/gpio/gpiolib-acpi.c           | 15 ++++--
 include/linux/acpi.h                  |  7 +++
 sound/soc/intel/boards/bytcr_rt5651.c | 74 ++++-----------------------
 3 files changed, 27 insertions(+), 69 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 259cf6ab969b..4d291b75cb9f 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -530,17 +530,24 @@ static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
 	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 		return 1;
 
-	if (lookup->n++ == lookup->index && !lookup->desc) {
+	if (!lookup->desc) {
 		const struct acpi_resource_gpio *agpio = &ares->data.gpio;
-		int pin_index = lookup->pin_index;
+		bool gpioint = agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
+		int pin_index;
 
+		if (lookup->info.quirks & ACPI_GPIO_QUIRK_ONLY_GPIOIO && gpioint)
+			lookup->index++;
+
+		if (lookup->n++ != lookup->index)
+			return 1;
+
+		pin_index = lookup->pin_index;
 		if (pin_index >= agpio->pin_table_length)
 			return 1;
 
 		lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 					      agpio->pin_table[pin_index]);
-		lookup->info.gpioint =
-			agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
+		lookup->info.gpioint = gpioint;
 
 		/*
 		 * Polarity and triggering are only specified for GpioInt
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 1e89c688139f..430fd0b6df7b 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1020,6 +1020,13 @@ struct acpi_gpio_mapping {
 
 /* Ignore IoRestriction field */
 #define ACPI_GPIO_QUIRK_NO_IO_RESTRICTION	BIT(0)
+/*
+ * When ACPI GPIO mapping table is in use the index parameter inside it
+ * refers to the GPIO resource in _CRS method. That index has no
+ * distinction of actual type of the resource. When consumer wants to
+ * get GpioIo type explicitly, this quirk may be used.
+ */
+#define ACPI_GPIO_QUIRK_ONLY_GPIOIO		BIT(1)
 
 	unsigned int quirks;
 };
diff --git a/sound/soc/intel/boards/bytcr_rt5651.c b/sound/soc/intel/boards/bytcr_rt5651.c
index b618d984e2d5..99d0c01a1bec 100644
--- a/sound/soc/intel/boards/bytcr_rt5651.c
+++ b/sound/soc/intel/boards/bytcr_rt5651.c
@@ -844,74 +844,18 @@ static const struct x86_cpu_id cherrytrail_cpu_ids[] = {
 	{}
 };
 
-static const struct acpi_gpio_params first_gpio = { 0, 0, false };
-static const struct acpi_gpio_params second_gpio = { 1, 0, false };
+static const struct acpi_gpio_params ext_amp_enable_gpios = { 0, 0, false };
 
-static const struct acpi_gpio_mapping byt_rt5651_amp_en_first[] = {
-	{ "ext-amp-enable-gpios", &first_gpio, 1 },
-	{ },
-};
-
-static const struct acpi_gpio_mapping byt_rt5651_amp_en_second[] = {
-	{ "ext-amp-enable-gpios", &second_gpio, 1 },
+static const struct acpi_gpio_mapping cht_rt5651_gpios[] = {
+	/*
+	 * Some boards have I2cSerialBusV2, GpioIo, GpioInt as ACPI resources,
+	 * other boards may  have I2cSerialBusV2, GpioInt, GpioIo instead.
+	 * We want the GpioIo one for the ext-amp-enable-gpio.
+	 */
+	{ "ext-amp-enable-gpios", &ext_amp_enable_gpios, 1, ACPI_GPIO_QUIRK_ONLY_GPIOIO },
 	{ },
 };
 
-/*
- * Some boards have I2cSerialBusV2, GpioIo, GpioInt as ACPI resources, other
- * boards may  have I2cSerialBusV2, GpioInt, GpioIo instead. We want the
- * GpioIo one for the ext-amp-enable-gpio and both count for the index in
- * acpi_gpio_params index.  So we have 2 different mappings and the code
- * below figures out which one to use.
- */
-struct byt_rt5651_acpi_resource_data {
-	int gpio_count;
-	int gpio_int_idx;
-};
-
-static int snd_byt_rt5651_acpi_resource(struct acpi_resource *ares, void *arg)
-{
-	struct byt_rt5651_acpi_resource_data *data = arg;
-
-	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
-		return 0;
-
-	if (ares->data.gpio.connection_type == ACPI_RESOURCE_GPIO_TYPE_INT)
-		data->gpio_int_idx = data->gpio_count;
-
-	data->gpio_count++;
-	return 0;
-}
-
-static void snd_byt_rt5651_mc_pick_amp_en_gpio_mapping(struct device *codec)
-{
-	struct byt_rt5651_acpi_resource_data data = { 0, -1 };
-	LIST_HEAD(resources);
-	int ret;
-
-	ret = acpi_dev_get_resources(ACPI_COMPANION(codec), &resources,
-				     snd_byt_rt5651_acpi_resource, &data);
-	if (ret < 0) {
-		dev_warn(codec, "Failed to get ACPI resources, not adding external amplifier GPIO mapping\n");
-		return;
-	}
-
-	/* All info we need is gathered during the walk */
-	acpi_dev_free_resource_list(&resources);
-
-	switch (data.gpio_int_idx) {
-	case 0:
-		byt_rt5651_gpios = byt_rt5651_amp_en_second;
-		break;
-	case 1:
-		byt_rt5651_gpios = byt_rt5651_amp_en_first;
-		break;
-	default:
-		dev_warn(codec, "Unknown GpioInt index %d, not adding external amplifier GPIO mapping\n",
-			 data.gpio_int_idx);
-	}
-}
-
 struct acpi_chan_package {   /* ACPICA seems to require 64 bit integers */
 	u64 aif_value;       /* 1: AIF1, 2: AIF2 */
 	u64 mclock_value;    /* usually 25MHz (0x17d7940), ignored */
@@ -1037,7 +981,7 @@ static int snd_byt_rt5651_mc_probe(struct platform_device *pdev)
 
 	/* Cherry Trail devices use an external amplifier enable gpio */
 	if (x86_match_cpu(cherrytrail_cpu_ids) && !byt_rt5651_gpios)
-		snd_byt_rt5651_mc_pick_amp_en_gpio_mapping(codec_dev);
+		byt_rt5651_gpios = cht_rt5651_gpios;
 
 	if (byt_rt5651_gpios) {
 		devm_acpi_dev_add_driver_gpios(codec_dev, byt_rt5651_gpios);
-- 
2.20.1