Re: [PATCH 06/21] ata: libahci_platform: Add function returning a clock-handle by id

[Damien Le Moal]

On 3/24/22 09:16, Serge Semin wrote:
> Since all the clocks are retrieved by the method
> ahci_platform_get_resources() there is no need for the glue-drivers to be
> looking for some particular of them in the kernel clocks table again.
> Instead we suggest to add a simple method returning a device-specific
> clock with passed connection ID if it is managed to be found. Otherwise
> the function will return NULL. Thus the glue-drivers won't need to either

"glue-drivers" is really unclear. What do you mean ?

> manually touching the hpriv->clks array or calling clk_get()-friends. The
> AHCI platform drivers will be able to use the new function right after the
> ahci_platform_get_resources() method invocation and up to the device
> removal.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/ata/libahci_platform.c | 27 +++++++++++++++++++++++++++
>  include/linux/ahci_platform.h  |  3 +++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> index d805ddc3a024..4fb9629c03ab 100644
> --- a/drivers/ata/libahci_platform.c
> +++ b/drivers/ata/libahci_platform.c
> @@ -94,6 +94,33 @@ void ahci_platform_disable_phys(struct ahci_host_priv *hpriv)
>  }
>  EXPORT_SYMBOL_GPL(ahci_platform_disable_phys);
>  
> +/**
> + * ahci_platform_find_clk - Find platform clock
> + * @hpriv: host private area to store config values
> + * @con_id: clock connection ID
> + *
> + * This function returns point to the clock descriptor of the clock with
> + * passed ID.
> + *
> + * RETURNS:
> + * Pointer to the clock descriptor on success otherwise NULL
> + */
> +struct clk *ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con_id)
> +{
> +	struct clk *clk = NULL;
> +	int i;
> +
> +	for (i = 0; i < hpriv->n_clks; i++) {
> +		if (!strcmp(hpriv->clks[i].id, con_id)) {
> +			clk = hpriv->clks[i].clk;
> +			break;
> +		}
> +	}
> +
> +	return clk;
> +}
> +EXPORT_SYMBOL_GPL(ahci_platform_find_clk);
> +
>  /**
>   * ahci_platform_enable_clks - Enable platform clocks
>   * @hpriv: host private area to store config values
> diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h
> index 49e5383d4222..fd964e6a68d6 100644
> --- a/include/linux/ahci_platform.h
> +++ b/include/linux/ahci_platform.h
> @@ -13,6 +13,7 @@
>  
>  #include <linux/compiler.h>
>  
> +struct clk;
>  struct device;
>  struct ata_port_info;
>  struct ahci_host_priv;
> @@ -21,6 +22,8 @@ struct scsi_host_template;
>  
>  int ahci_platform_enable_phys(struct ahci_host_priv *hpriv);
>  void ahci_platform_disable_phys(struct ahci_host_priv *hpriv);
> +struct clk *
> +ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con_id);

No users for this function ?

>  int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);
>  void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);
>  int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv);


-- 
Damien Le Moal
Western Digital Research