| Message ID | 20220427180853.35970-5-kdasu.kdev@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: sdhci-brcmstb: host controller clock enhancements | expand |
On 4/27/22 11:08, Kamal Dasu wrote: > From: Al Cooper <alcooperx@gmail.com> > > The 72116B0 has improved SDIO controllers that allow the max clock > rate to be increased from a max of 100MHz to a max of 150MHz. The > driver will need to get the clock and increase it's default rate > and override the caps register, that still indicates a max of 100MHz. > The new clock will be named "sdio_freq" in the DT node's "clock-names" > list. The driver will use a DT property, "clock-frequency", to > enable this functionality and will get the actual rate in MHz > from the property to allow various speeds to be requested. > > Signed-off-by: Al Cooper <alcooperx@gmail.com> > Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com> > --- > drivers/mmc/host/sdhci-brcmstb.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c > index 683d0c685748..51a23e9f4535 100644 > --- a/drivers/mmc/host/sdhci-brcmstb.c > +++ b/drivers/mmc/host/sdhci-brcmstb.c > @@ -250,6 +250,7 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) > struct sdhci_pltfm_host *pltfm_host; > const struct of_device_id *match; > struct sdhci_brcmstb_priv *priv; > + u32 base_clock_hz = 0; > struct sdhci_host *host; > struct resource *iomem; > struct clk *clk; > @@ -330,6 +331,30 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) > if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT) > host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL; > > + /* Change the base clock frequency if the DT property exists */ > + if (device_property_read_u32(&pdev->dev, "max-frequency", > + &base_clock_hz) == 0) { > + struct clk *master_clk; > + u32 actual_clock_mhz; > + > + master_clk = devm_clk_get(&pdev->dev, "sdio_freq"); > + if (IS_ERR(master_clk)) { > + dev_warn(&pdev->dev, > + "Clock for \"sdio_freq\" was not found\n"); > + } else { > + clk_set_rate(master_clk, base_clock_hz); It seems to me that you should enable the clock before getting its rate, otherwise this may not return a valid rate. You might also consider reducing the indentation a little bit by using a label.
diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c index 683d0c685748..51a23e9f4535 100644 --- a/drivers/mmc/host/sdhci-brcmstb.c +++ b/drivers/mmc/host/sdhci-brcmstb.c @@ -250,6 +250,7 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) struct sdhci_pltfm_host *pltfm_host; const struct of_device_id *match; struct sdhci_brcmstb_priv *priv; + u32 base_clock_hz = 0; struct sdhci_host *host; struct resource *iomem; struct clk *clk; @@ -330,6 +331,30 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev) if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT) host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL; + /* Change the base clock frequency if the DT property exists */ + if (device_property_read_u32(&pdev->dev, "max-frequency", + &base_clock_hz) == 0) { + struct clk *master_clk; + u32 actual_clock_mhz; + + master_clk = devm_clk_get(&pdev->dev, "sdio_freq"); + if (IS_ERR(master_clk)) { + dev_warn(&pdev->dev, + "Clock for \"sdio_freq\" was not found\n"); + } else { + clk_set_rate(master_clk, base_clock_hz); + actual_clock_mhz = clk_get_rate(master_clk) / 1000000; + + host->caps &= ~SDHCI_CLOCK_V3_BASE_MASK; + host->caps |= + (actual_clock_mhz << SDHCI_CLOCK_BASE_SHIFT); + /* Disable presets because they are now incorrect */ + host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN; + dev_dbg(&pdev->dev, + "Base Clock Frequency changed to %dMHz\n", + actual_clock_mhz); + } + } res = sdhci_brcmstb_add_host(host, priv); if (res) goto err;