[PATCH V5 4/9] mmc: bcm2835: Introduce proper clock handling
Ulf Hansson
ulf.hansson at linaro.org
Mon Oct 28 04:43:58 PDT 2024
On Fri, 25 Oct 2024 at 12:36, Stefan Wahren <wahrenst at gmx.net> wrote:
>
> The custom sdhost controller on BCM2835 is feed by the critical VPU clock.
> In preparation for PM suspend/resume support, add a proper clock handling
> to the driver like in the other clock consumers (e.g. I2C).
>
> Move the clock handling behind mmc_of_parse(), because it could return
> with -EPROBE_DEFER and we want to minimize potential clock operation during
> boot phase.
>
> Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
Applied for next, thanks!
Kind regards
Uffe
> ---
> drivers/mmc/host/bcm2835.c | 29 ++++++++++++++++++-----------
> 1 file changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
> index 3d3eda5a337c..107666b7c1c8 100644
> --- a/drivers/mmc/host/bcm2835.c
> +++ b/drivers/mmc/host/bcm2835.c
> @@ -148,6 +148,7 @@ struct bcm2835_host {
> void __iomem *ioaddr;
> u32 phys_addr;
>
> + struct clk *clk;
> struct platform_device *pdev;
>
> unsigned int clock; /* Current clock speed */
> @@ -1345,7 +1346,6 @@ static int bcm2835_add_host(struct bcm2835_host *host)
> static int bcm2835_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> - struct clk *clk;
> struct bcm2835_host *host;
> struct mmc_host *mmc;
> const __be32 *regaddr_p;
> @@ -1393,15 +1393,6 @@ static int bcm2835_probe(struct platform_device *pdev)
> /* Ignore errors to fall back to PIO mode */
> }
>
> -
> - clk = devm_clk_get(dev, NULL);
> - if (IS_ERR(clk)) {
> - ret = dev_err_probe(dev, PTR_ERR(clk), "could not get clk\n");
> - goto err;
> - }
> -
> - host->max_clk = clk_get_rate(clk);
> -
> host->irq = platform_get_irq(pdev, 0);
> if (host->irq < 0) {
> ret = host->irq;
> @@ -1412,16 +1403,30 @@ static int bcm2835_probe(struct platform_device *pdev)
> if (ret)
> goto err;
>
> - ret = bcm2835_add_host(host);
> + host->clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(host->clk)) {
> + ret = dev_err_probe(dev, PTR_ERR(host->clk), "could not get clk\n");
> + goto err;
> + }
> +
> + ret = clk_prepare_enable(host->clk);
> if (ret)
> goto err;
>
> + host->max_clk = clk_get_rate(host->clk);
> +
> + ret = bcm2835_add_host(host);
> + if (ret)
> + goto err_clk;
> +
> platform_set_drvdata(pdev, host);
>
> dev_dbg(dev, "%s -> OK\n", __func__);
>
> return 0;
>
> +err_clk:
> + clk_disable_unprepare(host->clk);
> err:
> dev_dbg(dev, "%s -> err %d\n", __func__, ret);
> if (host->dma_chan_rxtx)
> @@ -1445,6 +1450,8 @@ static void bcm2835_remove(struct platform_device *pdev)
> cancel_work_sync(&host->dma_work);
> cancel_delayed_work_sync(&host->timeout_work);
>
> + clk_disable_unprepare(host->clk);
> +
> if (host->dma_chan_rxtx)
> dma_release_channel(host->dma_chan_rxtx);
>
> --
> 2.34.1
>
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