Re: [PATCH] ASoC: SOF: imx9: use SCMI API for LM management

[Iuliana Prodan <iuliana.prodan@nxp.com>]

On 11/12/2025 4:41 PM, Laurentiu Mihalcea wrote:
> From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
> 
> Linux supports NXP's LMM SCMI protocol so switch to using the appropriate
> API. The SIPs were intended to act as placeholders until the support for
> said protocol was upstreamed.
> 
> The underlying CPU protocol command from IMX_SIP_SRC_M_RESET_ADDR_SET is
> replaced by a LMM protocol command with the same effect (i.e. setting the
> boot address) since using the CPU protocol would require additional
> permissions (which TF-A already had). Apart from this, the SIPs are
> replaced by their equivalent Linux LMM commands.
> 
> Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
> ---
>   sound/soc/sof/imx/imx9.c | 36 ++++++++----------------------------
>   1 file changed, 8 insertions(+), 28 deletions(-)
> 
> diff --git a/sound/soc/sof/imx/imx9.c b/sound/soc/sof/imx/imx9.c
> index 853155d5990a..e56e8a1c8022 100644
> --- a/sound/soc/sof/imx/imx9.c
> +++ b/sound/soc/sof/imx/imx9.c
> @@ -3,19 +3,11 @@
>    * Copyright 2025 NXP
>    */
>   
> -#include <linux/arm-smccc.h>
> +#include <linux/firmware/imx/sm.h>
>   
>   #include "imx-common.h"
>   
> -#define IMX_SIP_SRC 0xC2000005
> -#define IMX_SIP_SRC_M_RESET_ADDR_SET 0x03
> -
> -#define IMX95_CPU_VEC_FLAGS_BOOT BIT(29)
> -
> -#define IMX_SIP_LMM 0xC200000F
> -#define IMX_SIP_LMM_BOOT 0x0
> -#define IMX_SIP_LMM_SHUTDOWN 0x1
> -
> +#define IMX95_M7_CPU_ID 0x1
>   #define IMX95_M7_LM_ID 0x1
>   
>   static struct snd_soc_dai_driver imx95_dai[] = {
> @@ -38,7 +30,6 @@ static int imx95_ops_init(struct snd_sof_dev *sdev)
>   
>   static int imx95_chip_probe(struct snd_sof_dev *sdev)
>   {
> -	struct arm_smccc_res smc_res;
>   	struct platform_device *pdev;
>   	struct resource *res;
>   
> @@ -49,31 +40,20 @@ static int imx95_chip_probe(struct snd_sof_dev *sdev)
>   		return dev_err_probe(sdev->dev, -ENODEV,
>   				     "failed to fetch SRAM region\n");
>   
> -	/* set core boot reset address */
> -	arm_smccc_smc(IMX_SIP_SRC, IMX_SIP_SRC_M_RESET_ADDR_SET, res->start,
> -		      IMX95_CPU_VEC_FLAGS_BOOT, 0, 0, 0, 0, &smc_res);
> -
> -	return smc_res.a0;
> +	return scmi_imx_lmm_reset_vector_set(IMX95_M7_LM_ID, IMX95_M7_CPU_ID,
> +					     0, res->start);

Please add a dependency for SND_SOC_SOF_IMX9 on CONFIG_IMX_SCMI_LMM_DRV. 
Without this, the functions scmi_imx_lmm_reset_vector_set and 
scmi_imx_lmm_operation will return -EOPNOTSUPP.

Iulia

>   }
>   
>   static int imx95_core_kick(struct snd_sof_dev *sdev)
>   {
> -	struct arm_smccc_res smc_res;
> -
> -	arm_smccc_smc(IMX_SIP_LMM, IMX_SIP_LMM_BOOT,
> -		      IMX95_M7_LM_ID, 0, 0, 0, 0, 0, &smc_res);
> -
> -	return smc_res.a0;
> +	return scmi_imx_lmm_operation(IMX95_M7_LM_ID, SCMI_IMX_LMM_BOOT, 0);
>   }
>   
>   static int imx95_core_shutdown(struct snd_sof_dev *sdev)
>   {
> -	struct arm_smccc_res smc_res;
> -
> -	arm_smccc_smc(IMX_SIP_LMM, IMX_SIP_LMM_SHUTDOWN,
> -		      IMX95_M7_LM_ID, 0, 0, 0, 0, 0, &smc_res);
> -
> -	return smc_res.a0;
> +	return scmi_imx_lmm_operation(IMX95_M7_LM_ID,
> +				      SCMI_IMX_LMM_SHUTDOWN,
> +				      SCMI_IMX_LMM_OP_FORCEFUL);
>   }
>   
>   static const struct imx_chip_ops imx95_chip_ops = {