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

From: Jaehoon Chung
Date: Thu Jun 30 2011 - 02:55:24 EST


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@xxxxxxxxxxx>
> ---
> 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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