Hi, Mr Chung.
> -----Original Message-----
> From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc-
> ow...@vger.kernel.org] On Behalf Of Jaehoon Chung
> Sent: Thursday, June 30, 2011 3:55 PM
> To: Seungwon Jeon
> Cc: linux-mmc@vger.kernel.org; c...@laptop.org; linux-
> ker...@vger.kernel.org; Kyungmin Park
> Subject: Re: [PATCH] mmc: dw_mmc: Supply clocks for both host and card.
>
> 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?
Yes, cclk is source clock for card I/O.
It can be different from Host operating clock(hclk).
Best regards,
Seunwgon.
> Regards,
> Jaehoon Chung
>
> Seungwon Jeon wrote:
> > Add enabling clocks for both host controller and card.
> >
> > Signed-off-by: Seungwon Jeon <tgih....@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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> >
>
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