Re: [PATCH] mmc: dw_mmc: Supply clocks for both host and card.

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi Mr.Jeon

What means cclk_name/ cclk enable?
Controlling card clock is possible?
Sorry, i didn't understand...
(My understanding is that if we set host clk, cclk is used with host_clk.)

Plz can you explain to me?

Regards,
Jaehoon Chung

Seungwon Jeon wrote:
> Add enabling clocks for both host controller and card.
> 
> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
> ---
>  drivers/mmc/host/dw_mmc.c  |   33 ++++++++++++++++++++++++++++++++-
>  include/linux/mmc/dw_mmc.h |    7 +++++++
>  2 files changed, 39 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 10b6979..a524416 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1797,6 +1797,24 @@ static int dw_mci_probe(struct platform_device *pdev)
>  		goto err_freehost;
>  	}
> 
> +	host->hclk = clk_get(&pdev->dev, pdata->hclk_name);
> +	if (IS_ERR(host->hclk)) {
> +		dev_err(&pdev->dev,
> +			"Failed to get hclk\n");
> +		ret = PTR_ERR(host->hclk);
> +		goto err_freehost;
> +	}
> +	clk_enable(host->hclk);
> +
> +	host->cclk = clk_get(&pdev->dev, pdata->cclk_name);
> +	if (IS_ERR(host->cclk)) {
> +		dev_err(&pdev->dev,
> +			"Failed to get cclk\n");
> +		ret = PTR_ERR(host->cclk);
> +		goto err_free_hclk;
> +	}
> +	clk_enable(host->cclk);
> +
>  	host->bus_hz = pdata->bus_hz;
>  	host->quirks = pdata->quirks;
> 
> @@ -1806,7 +1824,7 @@ static int dw_mci_probe(struct platform_device *pdev)
>  	ret = -ENOMEM;
>  	host->regs = ioremap(regs->start, regs->end - regs->start + 1);
>  	if (!host->regs)
> -		goto err_freehost;
> +		goto err_free_cclk;
> 
>  	host->dma_ops = pdata->dma_ops;
>  	dw_mci_init_dma(host);
> @@ -1945,6 +1963,13 @@ err_dmaunmap:
>  		regulator_put(host->vmmc);
>  	}
> 
> +err_free_cclk:
> +	clk_disable(host->cclk);
> +	clk_put(host->cclk);
> +
> +err_free_hclk:
> +	clk_disable(host->hclk);
> +	clk_put(host->hclk);
> 
>  err_freehost:
>  	kfree(host);
> @@ -1983,6 +2008,12 @@ static int __exit dw_mci_remove(struct platform_device *pdev)
>  		regulator_put(host->vmmc);
>  	}
> 
> +	clk_disable(host->cclk);
> +	clk_put(host->cclk);
> +
> +	clk_disable(host->hclk);
> +	clk_put(host->hclk);
> +
>  	iounmap(host->regs);
> 
>  	kfree(host);
> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
> index f3f68ee..56b3f27 100644
> --- a/include/linux/mmc/dw_mmc.h
> +++ b/include/linux/mmc/dw_mmc.h
> @@ -47,6 +47,8 @@ struct mmc_data;
>   * @cmd: The command currently being sent to the card, or NULL.
>   * @data: The data currently being transferred, or NULL if no data
>   *	transfer is in progress.
> + * @hclk: Clock for host.
> + * @cclk: Clock for card.
>   * @use_dma: Whether DMA channel is initialized or not.
>   * @sg_dma: Bus address of DMA buffer.
>   * @sg_cpu: Virtual address of DMA buffer.
> @@ -118,6 +120,8 @@ struct dw_mci {
>  	struct mmc_request	*mrq;
>  	struct mmc_command	*cmd;
>  	struct mmc_data		*data;
> +	struct clk		*hclk;
> +	struct clk		*cclk;
> 
>  	/* DMA interface members*/
>  	int			use_dma;
> @@ -218,6 +222,9 @@ struct dw_mci_board {
>  	/* delay in mS before detecting cards after interrupt */
>  	u32 detect_delay_ms;
> 
> +	char *hclk_name;
> +	char *cclk_name;
> +
>  	int (*init)(u32 slot_id, irq_handler_t , void *);
>  	int (*get_ro)(u32 slot_id);
>  	int (*get_cd)(u32 slot_id);
> --
> 1.7.0.4
> 
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