Re: [PATCH v5 5/5] soc: ti: pruss: Add helper functions to get/set PRUSS_CFG_GPMUX

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Thu, Mar 23, 2023 at 11:54:51AM +0530, MD Danish Anwar wrote:
> From: Tero Kristo <t-kristo@ti.com>
> 
> Add two new helper functions pruss_cfg_get_gpmux() & pruss_cfg_set_gpmux()
> to get and set the GP MUX mode for programming the PRUSS internal wrapper
> mux functionality as needed by usecases.
> 
> Co-developed-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> Reviewed-by: Roger Quadros <rogerq@kernel.org>
> ---
>  drivers/soc/ti/pruss.c           | 44 ++++++++++++++++++++++++++++++++
>  include/linux/remoteproc/pruss.h | 30 ++++++++++++++++++++++
>  2 files changed, 74 insertions(+)
> 
> diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
> index ac415442e85b..3aa3c38c6c79 100644
> --- a/drivers/soc/ti/pruss.c
> +++ b/drivers/soc/ti/pruss.c
> @@ -239,6 +239,50 @@ int pruss_cfg_xfr_enable(struct pruss *pruss, enum pru_type pru_type,
>  }
>  EXPORT_SYMBOL_GPL(pruss_cfg_xfr_enable);
>  
> +/**
> + * pruss_cfg_get_gpmux() - get the current GPMUX value for a PRU device
> + * @pruss: pruss instance
> + * @pru_id: PRU identifier (0-1)
> + * @mux: pointer to store the current mux value into
> + *
> + * Return: 0 on success, or an error code otherwise
> + */
> +int pruss_cfg_get_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 *mux)
> +{
> +	int ret = 0;
> +	u32 val;
> +
> +	if (pru_id < 0 || pru_id >= PRUSS_NUM_PRUS)
> +		return -EINVAL;
> +
> +	ret = pruss_cfg_read(pruss, PRUSS_CFG_GPCFG(pru_id), &val);
> +	if (!ret)
> +		*mux = (u8)((val & PRUSS_GPCFG_PRU_MUX_SEL_MASK) >>
> +			    PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);

What happens if @mux is NULL?

Thanks,
Mathieu


> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(pruss_cfg_get_gpmux);
> +
> +/**
> + * pruss_cfg_set_gpmux() - set the GPMUX value for a PRU device
> + * @pruss: pruss instance
> + * @pru_id: PRU identifier (0-1)
> + * @mux: new mux value for PRU
> + *
> + * Return: 0 on success, or an error code otherwise
> + */
> +int pruss_cfg_set_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 mux)
> +{
> +	if (mux >= PRUSS_GP_MUX_SEL_MAX ||
> +	    pru_id < 0 || pru_id >= PRUSS_NUM_PRUS)
> +		return -EINVAL;
> +
> +	return pruss_cfg_update(pruss, PRUSS_CFG_GPCFG(pru_id),
> +				PRUSS_GPCFG_PRU_MUX_SEL_MASK,
> +				(u32)mux << PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
> +}
> +EXPORT_SYMBOL_GPL(pruss_cfg_set_gpmux);
> +
>  static void pruss_of_free_clk_provider(void *data)
>  {
>  	struct device_node *clk_mux_np = data;
> diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h
> index bb001f712980..42f1586c62ac 100644
> --- a/include/linux/remoteproc/pruss.h
> +++ b/include/linux/remoteproc/pruss.h
> @@ -16,6 +16,24 @@
>  
>  #define PRU_RPROC_DRVNAME "pru-rproc"
>  
> +/*
> + * enum pruss_gp_mux_sel - PRUSS GPI/O Mux modes for the
> + * PRUSS_GPCFG0/1 registers
> + *
> + * NOTE: The below defines are the most common values, but there
> + * are some exceptions like on 66AK2G, where the RESERVED and MII2
> + * values are interchanged. Also, this bit-field does not exist on
> + * AM335x SoCs
> + */
> +enum pruss_gp_mux_sel {
> +	PRUSS_GP_MUX_SEL_GP = 0,
> +	PRUSS_GP_MUX_SEL_ENDAT,
> +	PRUSS_GP_MUX_SEL_RESERVED,
> +	PRUSS_GP_MUX_SEL_SD,
> +	PRUSS_GP_MUX_SEL_MII2,
> +	PRUSS_GP_MUX_SEL_MAX,
> +};
> +
>  /*
>   * enum pruss_gpi_mode - PRUSS GPI configuration modes, used
>   *			 to program the PRUSS_GPCFG0/1 registers
> @@ -110,6 +128,8 @@ int pruss_cfg_gpimode(struct pruss *pruss, enum pruss_pru_id pru_id,
>  int pruss_cfg_miirt_enable(struct pruss *pruss, bool enable);
>  int pruss_cfg_xfr_enable(struct pruss *pruss, enum pru_type pru_type,
>  			 bool enable);
> +int pruss_cfg_get_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 *mux);
> +int pruss_cfg_set_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 mux);
>  
>  #else
>  
> @@ -152,6 +172,16 @@ static inline int pruss_cfg_xfr_enable(struct pruss *pruss,
>  	return ERR_PTR(-EOPNOTSUPP);
>  }
>  
> +static inline int pruss_cfg_get_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 *mux)
> +{
> +	return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline int pruss_cfg_set_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 mux)
> +{
> +	return ERR_PTR(-EOPNOTSUPP);
> +}
> +
>  #endif /* CONFIG_TI_PRUSS */
>  
>  #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
> -- 
> 2.25.1
>