Messages in this thread | | | Subject | Re: [PATCH v3 2/3] mmc: sdhci-of-arasan: add phy support for sdhci-of-arasan | From | Shawn Lin <> | Date | Tue, 20 Oct 2015 17:11:59 +0800 |
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On 2015/10/20 16:39, Ulf Hansson wrote: > + Kishon > > On 20 October 2015 at 09:05, Shawn Lin <shawn.lin@rock-chips.com> wrote: >> This patch adds Generic PHY access for sdhci-of-arasan. Driver >> can get PHY handler from dt-binding, and power-on/init the PHY. >> Also we add pm ops for PHY here if CONFIG_PM_SLEEP is enabled. >> Currently, it's just mandatory for arasan,sdhci-5.1. >> >> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> >> >> Serise-changes: 3 >> - remove phy_init/exit for suspend/resume >> - adjust phy_int/power_on seq to make code more reasonable >> - simplify suspend/resume_phy >> >> Serise-changes: 2 >> - Keep phy as a mandatory requirement for arasan,sdhci-5.1 >> >> --- >> >> Changes in v2: None >> >> drivers/mmc/host/sdhci-of-arasan.c | 87 ++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 87 insertions(+) >> >> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c >> index 75379cb..85bd0f9d 100644 >> --- a/drivers/mmc/host/sdhci-of-arasan.c >> +++ b/drivers/mmc/host/sdhci-of-arasan.c >> @@ -21,6 +21,7 @@ >> >> #include <linux/module.h> >> #include <linux/of_device.h> >> +#include <linux/phy/phy.h> >> #include "sdhci-pltfm.h" >> >> #define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c >> @@ -35,6 +36,7 @@ >> */ >> struct sdhci_arasan_data { >> struct clk *clk_ahb; >> + struct phy *phy; >> }; >> >> static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host) >> @@ -70,6 +72,42 @@ static struct sdhci_pltfm_data sdhci_arasan_pdata = { >> >> #ifdef CONFIG_PM_SLEEP >> /** >> + * sdhci_arasan_suspend_phy - Suspend phy method for the driver >> + * @phy: Handler of phy structure >> + * Returns 0 on success and error value on error >> + * >> + * Put the phy in a deactive state. >> + */ >> +static int sdhci_arasan_suspend_phy(struct phy *phy) >> +{ >> + int ret = 0; >> + >> + ret = phy_power_off(phy); >> + if (ret) > > This is an odd error handling, should you really do phy_power_on()? >
Thanks for these helpful comments.
Michal also mentioned this odd error handling. Well, I can't say whether it's okay, but at least large numbers of drivers which adopt generic phy interfaces don't even test the return value of power_off/on.
Anyway, remove this err handling is okay to me. I will do it.
>> + phy_power_on(phy); >> + >> + return ret; >> +} >> + >> +/** >> + * sdhci_arasan_resume_phy - Resume phy method for the driver >> + * @phy: Handler of phy structure >> + * Returns 0 on success and error value on error >> + * >> + * Put the phy in a active state. >> + */ >> +static int sdhci_arasan_resume_phy(struct phy *phy) >> +{ >> + int ret = 0; >> + >> + ret = phy_power_on(phy); >> + if (ret) > > Similar comment as above.
Ditto.
> >> + phy_power_off(phy); >> + >> + return ret; >> +} >> + >> +/** >> * sdhci_arasan_suspend - Suspend method for the driver >> * @dev: Address of the device structure >> * Returns 0 on success and error value on error >> @@ -88,6 +126,15 @@ static int sdhci_arasan_suspend(struct device *dev) >> if (ret) >> return ret; >> >> + if (!IS_ERR(sdhci_arasan->phy)) { >> + ret = sdhci_arasan_suspend_phy(sdhci_arasan->phy); >> + if (ret) { >> + dev_err(dev, "Cannot suspend phy.\n"); >> + sdhci_resume_host(host); > > This is an odd error handling, why do sdhci_resume_host()?
right, no need there, sorry for the bit.
> >> + return ret; >> + } >> + } >> + >> clk_disable(pltfm_host->clk); >> clk_disable(sdhci_arasan->clk_ahb); >> >> @@ -122,6 +169,16 @@ static int sdhci_arasan_resume(struct device *dev) >> return ret; >> } >> >> + if (!IS_ERR(sdhci_arasan->phy)) { >> + ret = sdhci_arasan_resume_phy(sdhci_arasan->phy); >> + if (ret) { >> + dev_err(dev, "Cannot resume phy.\n"); >> + clk_disable(sdhci_arasan->clk_ahb); >> + clk_disable(pltfm_host->clk); >> + return ret; > > The error handling is starting to be a bit complex in > sdhci_arasan_resume(), perhaps it's time to add some labels to make > the code more readable?
Agreed.
> >> + } >> + } >> + >> return sdhci_resume_host(host); >> } >> #endif /* ! CONFIG_PM_SLEEP */ >> @@ -166,6 +223,33 @@ static int sdhci_arasan_probe(struct platform_device *pdev) >> goto clk_dis_ahb; >> } >> >> + sdhci_arasan->phy = NULL; > > NULL isn't an error. You probably want something like: > sdhci_arasan->phy = ERR_PTR(-ENODEV); > > Although, I just realize that the phy API works a bit differently than > other APIs. More precisely, instead of returning an error while you > provide a NULL pointer to the APIs, it will treat it as a NOOP and > return a non-error code (at least according to the documentation). I > don't know why the phy API is different, but to me I prefer to use the > regular kernel style and thus, please adopt to my suggestion above. >
Got it.
>> + if (of_device_is_compatible(pdev->dev.of_node, >> + "arasan,sdhci-5.1")) { >> + sdhci_arasan->phy = devm_phy_get(&pdev->dev, >> + "phy_arasan"); >> + if (IS_ERR(sdhci_arasan->phy)) { >> + ret = -ENODEV; > > You should give "ret" the error code from devm_phy_get(), via > PTR_ERR(sdhci_arasan->phy).
Ah, yes.
> >> + dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n"); >> + goto clk_dis_ahb; >> + } >> + >> + ret = phy_init(sdhci_arasan->phy); >> + if (ret < 0) { >> + dev_err(&pdev->dev, "phy_init err.\n"); >> + phy_exit(sdhci_arasan->phy); > > phy_exit(), that seems like and odd error handling as the phy_init() failed.
As above, I am going to remove it.
> >> + goto clk_dis_ahb; >> + } >> + >> + ret = phy_power_on(sdhci_arasan->phy); >> + if (ret < 0) { >> + dev_err(&pdev->dev, "phy_power_on err.\n"); >> + phy_power_off(sdhci_arasan->phy); > > Similar comment as above. > >> + phy_exit(sdhci_arasan->phy); >> + goto clk_dis_ahb; >> + } >> + } >> + > > I believe you need at least phy_exit() if a failure occurs after this > point!? Perhaps some new error labels will deal with this nicely!?
right, I will do it.
> >> host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0); >> if (IS_ERR(host)) { >> ret = PTR_ERR(host); >> @@ -210,6 +294,9 @@ static int sdhci_arasan_remove(struct platform_device *pdev) >> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv; >> >> + if (!IS_ERR(sdhci_arasan->phy)) >> + phy_exit(sdhci_arasan->phy); >> + >> clk_disable_unprepare(sdhci_arasan->clk_ahb); >> >> return sdhci_pltfm_unregister(pdev); >> -- >> 2.3.7 >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > >
-- Best Regards Shawn Lin
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