On Mon, 28 Jan 2019 at 15:41, Martin Kepplinger <martink@xxxxxxxxx> wrote: > > From: Martin Kepplinger <martin.kepplinger@xxxxxxxxxxxxx> > > This adds support for explicitly switching the mmc's power on and off > which is needed for example for WL1837 WL1271 wifi controllers on imx28. > > While the wifi's vmmc-supply regulator can be configured in devicetree, > "ip link set wlan0 down" doesn't turn off the VMMC regulator which leads > to hangs when loading firmware, for example. > > Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxxxxxxxx> > --- > > > revision history > ---------------- > v4: re-added forgotten regulator_enable() during probe > v3: improve API usage as suggested by Ulf > v2: tested patch with changes suggested by Robin > v1: question, why https://patchwork.kernel.org/patch/4365751/ didn't get in > > > drivers/mmc/host/mxs-mmc.c | 34 +++++++++++++++++++++++++--------- > 1 file changed, 25 insertions(+), 9 deletions(-) > > diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c > index add1e70195ea..23d275269d61 100644 > --- a/drivers/mmc/host/mxs-mmc.c > +++ b/drivers/mmc/host/mxs-mmc.c > @@ -517,6 +517,22 @@ static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) > else > host->bus_width = 0; > > + switch (ios->power_mode) { > + case MMC_POWER_OFF: > + if (!IS_ERR(host->mmc->supply.vmmc)) > + mmc_regulator_set_ocr(host->mmc, > + host->mmc->supply.vmmc, 0); > + break; > + case MMC_POWER_UP: > + if (!IS_ERR(host->mmc->supply.vmmc)) > + mmc_regulator_set_ocr(host->mmc, > + host->mmc->supply.vmmc, > + ios->vdd); > + break; > + default: > + break; > + } > + > if (ios->clock) > mxs_ssp_set_clk_rate(&host->ssp, ios->clock); > } > @@ -588,7 +604,6 @@ static int mxs_mmc_probe(struct platform_device *pdev) > struct mmc_host *mmc; > struct resource *iores; > int ret = 0, irq_err; > - struct regulator *reg_vmmc; > struct mxs_ssp *ssp; > > irq_err = platform_get_irq(pdev, 0); > @@ -614,14 +629,15 @@ static int mxs_mmc_probe(struct platform_device *pdev) > host->mmc = mmc; > host->sdio_irq_en = 0; > > - reg_vmmc = devm_regulator_get(&pdev->dev, "vmmc"); > - if (!IS_ERR(reg_vmmc)) { > - ret = regulator_enable(reg_vmmc); > - if (ret) { > - dev_err(&pdev->dev, > - "Failed to enable vmmc regulator: %d\n", ret); > - goto out_mmc_free; > - } > + ret = mmc_regulator_get_supply(mmc); > + if (ret == -EPROBE_DEFER) > + goto out_mmc_free; > + > + ret = regulator_enable(mmc->supply.vmmc); This is wrong, as it may cause the regulator usage count to become wrongly balanced. Instead, via ->set_ios() when calling mmc_regulator_set_ocr(), it will take care of enabling and disabling the regulator depending of the requested vdd voltage level. > + if (ret) { > + dev_err(&pdev->dev, > + "Failed to enable vmmc regulator: %d\n", ret); > + goto out_mmc_free; > } > > ssp->clk = devm_clk_get(&pdev->dev, NULL); > -- > 2.20.1 > BTW, you didn't really answer my earlier question about the TI WiFi chip. Doesn't you need a special clock for WiFi chip as well? How do you intend to manage that? Kind regards Uffe
