[PATCH v4] ASoC: tas2783-sdw: add firmware download status check

[Baojun Xu <baojun.xu@ti.com>]

Currently, the firmware download is unnecessarily triggered on every
system resume from suspend, causing significant wake-up latency. However,
this step is redundant if the AMP remains powered on.

Signed-off-by: Baojun Xu <baojun.xu@ti.com>
---
v4:
 - Since first_hw_init is only required for download reduction, remove it
   when this feature is not enabled.
v3:
 - Updated description about memory page download reduce.
 - Removed the logic that skips memory page downloads.
v2:
 - Update register address from 0x07 to 7 and keep the line within the
   80-character limit.‌
 - ‌Remove stray/unnecessary changes.‌
 - ‌Change variable type to unsigned int to comply with API requirements.‌
 - ‌Replace usleep_range() with fsleep().‌
 - ‌Set idle_bias_on to 0 to enable low-power mode.
 - Reactivate the AMP after resume.
---
 sound/soc/codecs/tas2783-sdw.c | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/sound/soc/codecs/tas2783-sdw.c b/sound/soc/codecs/tas2783-sdw.c
index 04e10473c705..9519dbfc7299 100644
--- a/sound/soc/codecs/tas2783-sdw.c
+++ b/sound/soc/codecs/tas2783-sdw.c
@@ -857,6 +857,7 @@ static void tas2783_fw_ready(const struct firmware *fmw, void *context)
 		ret = -EINVAL;
 	} else {
 		tas2783_update_calibdata(tas_dev);
+		regmap_write(tas_dev->regmap, TASDEV_REG_SDW(0, 0, 7), 0x22);
 	}
 
 out:
@@ -996,7 +997,7 @@ static s32 tas_sdw_hw_params(struct snd_pcm_substream *substream,
 							TAS2783_SDCA_POW_STATE_ON);
 			if (!ret)
 				break;
-			usleep_range(2000, 2200);
+			fsleep(2200);
 		} while (retry--);
 	}
 
@@ -1119,7 +1120,7 @@ static const struct snd_soc_component_driver soc_codec_driver_tasdevice = {
 	.num_dapm_widgets = ARRAY_SIZE(tas_dapm_widgets),
 	.dapm_routes = tas_audio_map,
 	.num_dapm_routes = ARRAY_SIZE(tas_audio_map),
-	.idle_bias_on = 1,
+	.idle_bias_on = 0,
 	.endianness = 1,
 };
 
@@ -1252,25 +1253,29 @@ static s32 tas_fw_load(struct tas2783_prv *tas_dev, struct sdw_slave *slave)
 static s32 tas_io_init(struct device *dev, struct sdw_slave *slave)
 {
 	struct tas2783_prv *tas_dev = dev_get_drvdata(dev);
+	unsigned int val;
 	s32 ret;
 
 	if (tas_dev->hw_init)
 		return 0;
 
-	tas_dev->fw_dl_success = false;
+	regmap_read(tas_dev->regmap, TASDEV_REG_SDW(0, 0, 7), &val);
+	/* Check if the AMP is in reset status. */
+	if (val == 0x20) {
+		tas_dev->fw_dl_success = false;
 
-	ret = regmap_write(tas_dev->regmap, TAS2783_SW_RESET, 0x1);
-	if (ret) {
-		dev_err(dev, "sw reset failed, err=%d", ret);
-		return ret;
-	}
-	usleep_range(2000, 2200);
+		ret = regmap_write(tas_dev->regmap, TAS2783_SW_RESET, 0x1);
+		if (ret) {
+			dev_err(dev, "sw reset failed, err=%d", ret);
+			return ret;
+		}
+		fsleep(2200);
 
-	tas_dev->fw_use_fallback = false;
-	ret = tas_fw_load(tas_dev, slave);
-	if (!ret && tas_dev->fw_use_fallback)
+		tas_dev->fw_use_fallback = false;
 		ret = tas_fw_load(tas_dev, slave);
-
+		if (!ret && tas_dev->fw_use_fallback)
+			ret = tas_fw_load(tas_dev, slave);
+	}
 	if (!ret) {
 		if (tas_dev->sa_func_data)
 			ret = sdca_regmap_write_init(dev, tas_dev->regmap,
@@ -1279,6 +1284,8 @@ static s32 tas_io_init(struct device *dev, struct sdw_slave *slave)
 			ret = regmap_multi_reg_write(tas_dev->regmap, tas2783_init_seq,
 						     ARRAY_SIZE(tas2783_init_seq));
 
+		/* Re-active AMP after resume. */
+		regmap_write(tas_dev->regmap, TASDEV_REG_SDW(0, 0, 2), 0);
 		if (ret)
 			dev_err(tas_dev->dev,
 				"init writes failed, err=%d", ret);
-- 
2.25.1