| Message ID | 4d269f30b1122487a2b5c8b48e24f78f2b75a509.1570537903.git.nicolas.ferre@microchip.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [1/2] dt-bindings: sdhci-of-at91: add the microchip,sdcal-inverted property | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | success |
On Tue, Oct 08, 2019 at 02:34:32PM +0200, Nicolas Ferre wrote: > Add a property to keep the analog calibration cell powered. > This feature is specific to the Microchip SDHCI IP and outside > of the standard SDHCI register map. > > By always keeping it on, after a full reset sequence, we make sure > that this feature is activated and not disabled. > > We expose a hardware property to the DT as this feature can be used > to adapt SDHCI behavior vs. how the SDCAL SoC pin is connected > on the board. > > Note that managing properly this property would reduce > power consumption on some SAMA5D2 SiP revisions. > > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Thanks Ludovic > --- > drivers/mmc/host/sdhci-of-at91.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c > index e7d1920729fb..9571c4a882a9 100644 > --- a/drivers/mmc/host/sdhci-of-at91.c > +++ b/drivers/mmc/host/sdhci-of-at91.c > @@ -27,6 +27,9 @@ > #define SDMMC_CACR 0x230 > #define SDMMC_CACR_CAPWREN BIT(0) > #define SDMMC_CACR_KEY (0x46 << 8) > +#define SDMMC_CALCR 0x240 > +#define SDMMC_CALCR_EN BIT(0) > +#define SDMMC_CALCR_ALWYSON BIT(4) > > #define SDHCI_AT91_PRESET_COMMON_CONF 0x400 /* drv type B, programmable clock mode */ > > @@ -35,6 +38,7 @@ struct sdhci_at91_priv { > struct clk *gck; > struct clk *mainck; > bool restore_needed; > + bool cal_always_on; > }; > > static void sdhci_at91_set_force_card_detect(struct sdhci_host *host) > @@ -116,10 +120,17 @@ static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, > > static void sdhci_at91_reset(struct sdhci_host *host, u8 mask) > { > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host); > + > sdhci_reset(host, mask); > > if (host->mmc->caps & MMC_CAP_NONREMOVABLE) > sdhci_at91_set_force_card_detect(host); > + > + if (priv->cal_always_on && (mask & SDHCI_RESET_ALL)) > + sdhci_writel(host, SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN, > + SDMMC_CALCR); > } > > static const struct sdhci_ops sdhci_at91_sama5d2_ops = { > @@ -345,6 +356,14 @@ static int sdhci_at91_probe(struct platform_device *pdev) > > priv->restore_needed = false; > > + /* > + * if SDCAL pin is wrongly connected, we must enable > + * the analog calibration cell permanently. > + */ > + priv->cal_always_on = > + device_property_read_bool(&pdev->dev, > + "microchip,sdcal-inverted"); > + > ret = mmc_of_parse(host->mmc); > if (ret) > goto clocks_disable_unprepare; > -- > 2.17.1 >
On Tue, 8 Oct 2019 14:34:31 +0200, Nicolas Ferre wrote: > Add the specific microchip,sdcal-inverted property to at91 sdhci > device binding. > This optional property describes how the SoC SDCAL pin is connected. > It could be handled at SiP, SoM or board level. > > This property read by at91 sdhci driver will allow to put in place a > software workaround that would reduce power consumption. > > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> > --- > Documentation/devicetree/bindings/mmc/sdhci-atmel.txt | 5 +++++ > 1 file changed, 5 insertions(+) > Reviewed-by: Rob Herring <robh@kernel.org>
On Tue, 8 Oct 2019 at 14:34, Nicolas Ferre <nicolas.ferre@microchip.com> wrote: > > Add the specific microchip,sdcal-inverted property to at91 sdhci > device binding. > This optional property describes how the SoC SDCAL pin is connected. > It could be handled at SiP, SoM or board level. > > This property read by at91 sdhci driver will allow to put in place a > software workaround that would reduce power consumption. > > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Applied for next, thanks! Kind regards Uffe > --- > Documentation/devicetree/bindings/mmc/sdhci-atmel.txt | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt > index 1b662d7171a0..503c6dbac1b2 100644 > --- a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt > +++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt > @@ -9,6 +9,11 @@ Required properties: > - clocks: Phandlers to the clocks. > - clock-names: Must be "hclock", "multclk", "baseclk"; > > +Optional properties: > +- microchip,sdcal-inverted: when present, polarity on the SDCAL SoC pin is > + inverted. The default polarity for this signal is described in the datasheet. > + For instance on SAMA5D2, the pin is usually tied to the GND with a resistor > + and a capacitor (see "SDMMC I/O Calibration" chapter). > > Example: > > -- > 2.17.1 >
On Tue, 8 Oct 2019 at 14:34, Nicolas Ferre <nicolas.ferre@microchip.com> wrote: > > Add a property to keep the analog calibration cell powered. > This feature is specific to the Microchip SDHCI IP and outside > of the standard SDHCI register map. > > By always keeping it on, after a full reset sequence, we make sure > that this feature is activated and not disabled. > > We expose a hardware property to the DT as this feature can be used > to adapt SDHCI behavior vs. how the SDCAL SoC pin is connected > on the board. > > Note that managing properly this property would reduce > power consumption on some SAMA5D2 SiP revisions. > > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Applied for next, thanks! Kind regards Uffe > --- > drivers/mmc/host/sdhci-of-at91.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c > index e7d1920729fb..9571c4a882a9 100644 > --- a/drivers/mmc/host/sdhci-of-at91.c > +++ b/drivers/mmc/host/sdhci-of-at91.c > @@ -27,6 +27,9 @@ > #define SDMMC_CACR 0x230 > #define SDMMC_CACR_CAPWREN BIT(0) > #define SDMMC_CACR_KEY (0x46 << 8) > +#define SDMMC_CALCR 0x240 > +#define SDMMC_CALCR_EN BIT(0) > +#define SDMMC_CALCR_ALWYSON BIT(4) > > #define SDHCI_AT91_PRESET_COMMON_CONF 0x400 /* drv type B, programmable clock mode */ > > @@ -35,6 +38,7 @@ struct sdhci_at91_priv { > struct clk *gck; > struct clk *mainck; > bool restore_needed; > + bool cal_always_on; > }; > > static void sdhci_at91_set_force_card_detect(struct sdhci_host *host) > @@ -116,10 +120,17 @@ static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, > > static void sdhci_at91_reset(struct sdhci_host *host, u8 mask) > { > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host); > + > sdhci_reset(host, mask); > > if (host->mmc->caps & MMC_CAP_NONREMOVABLE) > sdhci_at91_set_force_card_detect(host); > + > + if (priv->cal_always_on && (mask & SDHCI_RESET_ALL)) > + sdhci_writel(host, SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN, > + SDMMC_CALCR); > } > > static const struct sdhci_ops sdhci_at91_sama5d2_ops = { > @@ -345,6 +356,14 @@ static int sdhci_at91_probe(struct platform_device *pdev) > > priv->restore_needed = false; > > + /* > + * if SDCAL pin is wrongly connected, we must enable > + * the analog calibration cell permanently. > + */ > + priv->cal_always_on = > + device_property_read_bool(&pdev->dev, > + "microchip,sdcal-inverted"); > + > ret = mmc_of_parse(host->mmc); > if (ret) > goto clocks_disable_unprepare; > -- > 2.17.1 >
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt index 1b662d7171a0..503c6dbac1b2 100644 --- a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt +++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt @@ -9,6 +9,11 @@ Required properties: - clocks: Phandlers to the clocks. - clock-names: Must be "hclock", "multclk", "baseclk"; +Optional properties: +- microchip,sdcal-inverted: when present, polarity on the SDCAL SoC pin is + inverted. The default polarity for this signal is described in the datasheet. + For instance on SAMA5D2, the pin is usually tied to the GND with a resistor + and a capacitor (see "SDMMC I/O Calibration" chapter). Example:
Add the specific microchip,sdcal-inverted property to at91 sdhci device binding. This optional property describes how the SoC SDCAL pin is connected. It could be handled at SiP, SoM or board level. This property read by at91 sdhci driver will allow to put in place a software workaround that would reduce power consumption. Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> --- Documentation/devicetree/bindings/mmc/sdhci-atmel.txt | 5 +++++ 1 file changed, 5 insertions(+)