ASoC: tegra: tegra20_ac97: Convert to use GPIO descriptors

The Tegra20 AC97 driver is using the legacy GPIO APIs in
<linux/of_gpio.h> and <linux/gpio.h> to obtain GPIOs for reset
and sync.

Convert it over and fix the polarity error on the RESET line
in the process: this reset line is clearly active low. Just
fix the one in-tree device tree site using it at the same
time.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://msgid.link/r/20231214-gpio-descriptors-sound-misc-v1-4-e3004176bd8b@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Linus Walleij

arch/arm/boot/dts/nvidia/tegra20-colibri.dtsi

@@ -446,7 +446,7 @@
 	tegra_ac97: ac97@70002000 {
 		status = "okay";
 		nvidia,codec-reset-gpio =
-			<&gpio TEGRA_GPIO(V, 0) GPIO_ACTIVE_HIGH>;
+			<&gpio TEGRA_GPIO(V, 0) GPIO_ACTIVE_LOW>;
 		nvidia,codec-sync-gpio =
 			<&gpio TEGRA_GPIO(P, 0) GPIO_ACTIVE_HIGH>;
 	};

sound/soc/tegra/tegra20_ac97.c

@@ -12,12 +12,11 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
@@ -39,11 +38,15 @@ static void tegra20_ac97_codec_reset(struct snd_ac97 *ac97)
 	u32 readback;
 	unsigned long timeout;
 
-	/* reset line is not driven by DAC pad group, have to toggle GPIO */
-	gpio_set_value(workdata->reset_gpio, 0);
+	/*
+	 * The reset line is not driven by DAC pad group, have to toggle GPIO.
+	 * The RESET line is active low but this is abstracted by the GPIO
+	 * library.
+	 */
+	gpiod_set_value(workdata->reset_gpio, 1);
 	udelay(2);
 
-	gpio_set_value(workdata->reset_gpio, 1);
+	gpiod_set_value(workdata->reset_gpio, 0);
 	udelay(2);
 
 	timeout = jiffies + msecs_to_jiffies(100);
@@ -66,14 +69,10 @@ static void tegra20_ac97_codec_warm_reset(struct snd_ac97 *ac97)
 	 * the controller cmd is not working, have to toggle sync line
 	 * manually.
 	 */
-	gpio_request(workdata->sync_gpio, "codec-sync");
-
-	gpio_direction_output(workdata->sync_gpio, 1);
-
+	gpiod_direction_output(workdata->sync_gpio, 1);
 	udelay(2);
-	gpio_set_value(workdata->sync_gpio, 0);
+	gpiod_set_value(workdata->sync_gpio, 0);
 	udelay(2);
-	gpio_free(workdata->sync_gpio);
 
 	timeout = jiffies + msecs_to_jiffies(100);
 
@@ -342,28 +341,26 @@ static int tegra20_ac97_platform_probe(struct platform_device *pdev)
 		goto err_clk_put;
 	}
 
-	ac97->reset_gpio = of_get_named_gpio(pdev->dev.of_node,
-					     "nvidia,codec-reset-gpio", 0);
-	if (gpio_is_valid(ac97->reset_gpio)) {
-		ret = devm_gpio_request_one(&pdev->dev, ac97->reset_gpio,
-					    GPIOF_OUT_INIT_HIGH, "codec-reset");
-		if (ret) {
-			dev_err(&pdev->dev, "could not get codec-reset GPIO\n");
-			goto err_clk_put;
-		}
-	} else {
-		dev_err(&pdev->dev, "no codec-reset GPIO supplied\n");
-		ret = -EINVAL;
+	/* Obtain RESET de-asserted */
+	ac97->reset_gpio = devm_gpiod_get(&pdev->dev,
+					  "nvidia,codec-reset",
+					  GPIOD_OUT_LOW);
+	if (IS_ERR(ac97->reset_gpio)) {
+		ret = PTR_ERR(ac97->reset_gpio);
+		dev_err(&pdev->dev, "no RESET GPIO supplied: %d\n", ret);
 		goto err_clk_put;
 	}
-
-	ac97->sync_gpio = of_get_named_gpio(pdev->dev.of_node,
-					    "nvidia,codec-sync-gpio", 0);
-	if (!gpio_is_valid(ac97->sync_gpio)) {
-		dev_err(&pdev->dev, "no codec-sync GPIO supplied\n");
-		ret = -EINVAL;
+	gpiod_set_consumer_name(ac97->reset_gpio, "codec-reset");
+
+	ac97->sync_gpio = devm_gpiod_get(&pdev->dev,
+					 "nvidia,codec-sync",
+					 GPIOD_OUT_LOW);
+	if (IS_ERR(ac97->sync_gpio)) {
+		ret = PTR_ERR(ac97->sync_gpio);
+		dev_err(&pdev->dev, "no codec-sync GPIO supplied: %d\n", ret);
 		goto err_clk_put;
 	}
+	gpiod_set_consumer_name(ac97->sync_gpio, "codec-sync");
 
 	ac97->capture_dma_data.addr = mem->start + TEGRA20_AC97_FIFO_RX1;
 	ac97->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;

sound/soc/tegra/tegra20_ac97.h

@@ -80,7 +80,7 @@ struct tegra20_ac97 {
 	struct snd_dmaengine_dai_dma_data playback_dma_data;
 	struct reset_control *reset;
 	struct regmap *regmap;
-	int reset_gpio;
-	int sync_gpio;
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *sync_gpio;
 };
 #endif /* __TEGRA20_AC97_H__ */