[PATCH 5/9] ASoC: ux500: Deassert the MSP reset during probe

[Linus Walleij <linusw@kernel.org>]

The devicetree has described each MSP reset line since the PRCC reset
controller was added, but the driver never acquires or deasserts it. The
block can consequently remain inaccessible when firmware has left it in
reset.

Acquire the reset exclusively and keep it deasserted for the lifetime of
the bound device.

Fixes: 95f04048325c ("ARM: dts: ux500: Add reset lines to IP blocks")
Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 sound/soc/ux500/ux500_msp_dai.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/ux500/ux500_msp_dai.c b/sound/soc/ux500/ux500_msp_dai.c
index 599de5de23dd..8450a4799c0f 100644
--- a/sound/soc/ux500/ux500_msp_dai.c
+++ b/sound/soc/ux500/ux500_msp_dai.c
@@ -14,6 +14,7 @@
 #include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/regulator/consumer.h>
+#include <linux/reset.h>
 #include <linux/mfd/dbx500-prcmu.h>
 
 #include <sound/soc.h>
@@ -686,6 +687,7 @@ static const struct snd_soc_component_driver ux500_msp_component = {
 static int ux500_msp_drv_probe(struct platform_device *pdev)
 {
 	struct ux500_msp_i2s_drvdata *drvdata;
+	struct reset_control *reset;
 	int ret = 0;
 
 	drvdata = devm_kzalloc(&pdev->dev,
@@ -733,6 +735,11 @@ static int ux500_msp_drv_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	reset = devm_reset_control_get_exclusive_deasserted(&pdev->dev, NULL);
+	if (IS_ERR(reset))
+		return dev_err_probe(&pdev->dev, PTR_ERR(reset),
+				     "Failed to deassert MSP reset\n");
+
 	ret = ux500_msp_i2s_init_msp(pdev, &drvdata->msp);
 	if (ret) {
 		dev_err(&pdev->dev,

-- 
2.55.0