[PATCH 1/2] ASoC: SOF: mediatek: Revise mt8195 boot flow

[Pierre-Louis Bossart]

From: YC Hung <yc.hung at mediatek.com>

1. Revise hifixdsp shutdown flow to pull runstall high then reset high.
2. Add 1 us delay between D/BRESET high and low for 10 DSP cycles(26M)
   based on IP vendor's suggestion.

Signed-off-by: YC Hung <yc.hung at mediatek.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Li-Yu Yu <afg984 at gmail.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: KuanHsun Cheng <Allen-KH.Cheng at mediatek.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi at linux.intel.com>
---
 sound/soc/sof/mediatek/mt8195/mt8195-loader.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/sound/soc/sof/mediatek/mt8195/mt8195-loader.c b/sound/soc/sof/mediatek/mt8195/mt8195-loader.c
index ed18d6379e92..5bdbb1460fe7 100644
--- a/sound/soc/sof/mediatek/mt8195/mt8195-loader.c
+++ b/sound/soc/sof/mediatek/mt8195/mt8195-loader.c
@@ -29,6 +29,9 @@ void sof_hifixdsp_boot_sequence(struct snd_sof_dev *sdev, u32 boot_addr)
 				ADSP_BRESET_SW | ADSP_DRESET_SW,
 				ADSP_BRESET_SW | ADSP_DRESET_SW);
 
+	/* delay 10 DSP cycles at 26M about 1us by IP vendor's suggestion */
+	udelay(1);
+
 	/* pull low DReset & BReset */
 	snd_sof_dsp_update_bits(sdev, DSP_REG_BAR, DSP_RESET_SW,
 				ADSP_BRESET_SW | ADSP_DRESET_SW,
@@ -46,11 +49,13 @@ void sof_hifixdsp_boot_sequence(struct snd_sof_dev *sdev, u32 boot_addr)
 
 void sof_hifixdsp_shutdown(struct snd_sof_dev *sdev)
 {
-	/* Clear to 0 firstly */
-	snd_sof_dsp_write(sdev, DSP_REG_BAR, DSP_RESET_SW, 0x0);
-
 	/* RUN_STALL pull high again to reset */
 	snd_sof_dsp_update_bits(sdev, DSP_REG_BAR, DSP_RESET_SW,
 				ADSP_RUNSTALL, ADSP_RUNSTALL);
+
+	/* pull high DReset & BReset */
+	snd_sof_dsp_update_bits(sdev, DSP_REG_BAR, DSP_RESET_SW,
+				ADSP_BRESET_SW | ADSP_DRESET_SW,
+				ADSP_BRESET_SW | ADSP_DRESET_SW);
 }
 
-- 
2.34.1