Re: [PATCH v2 8/8] imx_dsp_rproc: Use reset controller API to control the DSP

[Frank Li <Frank.li@nxp.com>]

On Wed, Feb 19, 2025 at 09:21:02PM +0200, Daniel Baluta wrote:
> Use the reset controller API to control the DSP on i.MX8MP. This way
> we can have a better control of the resources and avoid using a syscon
> to access the audiomix bits.
>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> Reviewed-by: Peng Fan <peng.fan@nxp.com>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> ---
>  drivers/remoteproc/imx_dsp_rproc.c | 25 +++++++++++++++++--------
>  drivers/remoteproc/imx_rproc.h     |  2 ++
>  2 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
> index ea5024919c2f..631563e4f86d 100644
> --- a/drivers/remoteproc/imx_dsp_rproc.c
> +++ b/drivers/remoteproc/imx_dsp_rproc.c
> @@ -19,6 +19,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  #include <linux/remoteproc.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
>
>  #include "imx_rproc.h"
> @@ -111,6 +112,7 @@ enum imx_dsp_rp_mbox_messages {
>   */
>  struct imx_dsp_rproc {
>  	struct regmap				*regmap;
> +	struct reset_control			*reset;
>  	struct rproc				*rproc;
>  	const struct imx_dsp_rproc_dcfg		*dsp_dcfg;
>  	struct clk_bulk_data			clks[DSP_RPROC_CLK_MAX];
> @@ -192,9 +194,7 @@ static int imx8mp_dsp_reset(struct imx_dsp_rproc *priv)
>  	/* Keep reset asserted for 10 cycles */
>  	usleep_range(1, 2);
>
> -	regmap_update_bits(priv->regmap, IMX8M_AudioDSP_REG2,
> -			   IMX8M_AudioDSP_REG2_RUNSTALL,
> -			   IMX8M_AudioDSP_REG2_RUNSTALL);
> +	reset_control_assert(priv->reset);
>
>  	/* Take the DSP out of reset and keep stalled for FW loading */
>  	pwrctl = readl(dap + IMX8M_DAP_PWRCTL);
> @@ -231,13 +231,9 @@ static int imx8ulp_dsp_reset(struct imx_dsp_rproc *priv)
>
>  /* Specific configuration for i.MX8MP */
>  static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8mp = {
> -	.src_reg	= IMX8M_AudioDSP_REG2,
> -	.src_mask	= IMX8M_AudioDSP_REG2_RUNSTALL,
> -	.src_start	= 0,
> -	.src_stop	= IMX8M_AudioDSP_REG2_RUNSTALL,
>  	.att		= imx_dsp_rproc_att_imx8mp,
>  	.att_size	= ARRAY_SIZE(imx_dsp_rproc_att_imx8mp),
> -	.method		= IMX_RPROC_MMIO,
> +	.method		= IMX_RPROC_RESET_CONTROLLER,
>  };
>
>  static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8mp = {
> @@ -329,6 +325,9 @@ static int imx_dsp_rproc_start(struct rproc *rproc)
>  					  true,
>  					  rproc->bootaddr);
>  		break;
> +	case IMX_RPROC_RESET_CONTROLLER:
> +		ret = reset_control_deassert(priv->reset);
> +		break;
>  	default:
>  		return -EOPNOTSUPP;
>  	}
> @@ -369,6 +368,9 @@ static int imx_dsp_rproc_stop(struct rproc *rproc)
>  					  false,
>  					  rproc->bootaddr);
>  		break;
> +	case IMX_RPROC_RESET_CONTROLLER:
> +		ret = reset_control_assert(priv->reset);
> +		break;
>  	default:
>  		return -EOPNOTSUPP;
>  	}
> @@ -995,6 +997,13 @@ static int imx_dsp_rproc_detect_mode(struct imx_dsp_rproc *priv)
>
>  		priv->regmap = regmap;
>  		break;
> +	case IMX_RPROC_RESET_CONTROLLER:
> +		priv->reset = devm_reset_control_get_exclusive(dev, NULL);
> +		if (IS_ERR(priv->reset)) {
> +			dev_err(dev, "Failed to get DSP reset control\n");
> +			return PTR_ERR(priv->reset);
> +		}
> +		break;
>  	default:
>  		ret = -EOPNOTSUPP;
>  		break;
> diff --git a/drivers/remoteproc/imx_rproc.h b/drivers/remoteproc/imx_rproc.h
> index 17a7d051c531..cfd38d37e146 100644
> --- a/drivers/remoteproc/imx_rproc.h
> +++ b/drivers/remoteproc/imx_rproc.h
> @@ -24,6 +24,8 @@ enum imx_rproc_method {
>  	IMX_RPROC_SMC,
>  	/* Through System Control Unit API */
>  	IMX_RPROC_SCU_API,
> +	/* Through Reset Controller API */
> +	IMX_RPROC_RESET_CONTROLLER,
>  };
>
>  /* dcfg flags */
> --
> 2.25.1
>