* [RESEND v4 0/2] add one regulator used to power up pcie phy
@ 2021-03-30 8:08 Richard Zhu
2021-03-30 8:08 ` [RESEND v4 1/2] dt-bindings: imx6q-pcie: " Richard Zhu
2021-03-30 8:08 ` [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3 Richard Zhu
0 siblings, 2 replies; 8+ messages in thread
From: Richard Zhu @ 2021-03-30 8:08 UTC (permalink / raw)
To: l.stach, andrew.smirnov, shawnguo, kw, bhelgaas, stefan,
lorenzo.pieralisi
Cc: linux-pci, linux-imx, linux-arm-kernel, linux-kernel, kernel
Changes:
Only add "Reviewed-by: Lucas Stach <l.stach@pengutronix.de>" in the
first patch. No other changes. Make it easier to be integrated later.
[RESEND v4 1/2] dt-bindings: imx6q-pcie: add one regulator used to
[RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is
^ permalink raw reply [flat|nested] 8+ messages in thread
* [RESEND v4 1/2] dt-bindings: imx6q-pcie: add one regulator used to power up pcie phy
2021-03-30 8:08 [RESEND v4 0/2] add one regulator used to power up pcie phy Richard Zhu
@ 2021-03-30 8:08 ` Richard Zhu
2021-05-06 16:08 ` Lucas Stach
2021-03-30 8:08 ` [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3 Richard Zhu
1 sibling, 1 reply; 8+ messages in thread
From: Richard Zhu @ 2021-03-30 8:08 UTC (permalink / raw)
To: l.stach, andrew.smirnov, shawnguo, kw, bhelgaas, stefan,
lorenzo.pieralisi
Cc: linux-pci, linux-imx, linux-arm-kernel, linux-kernel, kernel,
Richard Zhu
Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
the VREG_BYPASS bits of GPR registers should be cleared from default
value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
turned on.
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
---
Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index de4b2baf91e8..d8971ab99274 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -38,6 +38,9 @@ Optional properties:
The regulator will be enabled when initializing the PCIe host and
disabled either as part of the init process or when shutting down the
host.
+- vph-supply: Should specify the regulator in charge of VPH one of the three
+ PCIe PHY powers. This regulator can be supplied by both 1.8v and 3.3v voltage
+ supplies.
Additional required properties for imx6sx-pcie:
- clock names: Must include the following additional entries:
--
2.17.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3
2021-03-30 8:08 [RESEND v4 0/2] add one regulator used to power up pcie phy Richard Zhu
2021-03-30 8:08 ` [RESEND v4 1/2] dt-bindings: imx6q-pcie: " Richard Zhu
@ 2021-03-30 8:08 ` Richard Zhu
2021-05-06 21:09 ` Bjorn Helgaas
1 sibling, 1 reply; 8+ messages in thread
From: Richard Zhu @ 2021-03-30 8:08 UTC (permalink / raw)
To: l.stach, andrew.smirnov, shawnguo, kw, bhelgaas, stefan,
lorenzo.pieralisi
Cc: linux-pci, linux-imx, linux-arm-kernel, linux-kernel, kernel,
Richard Zhu
Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
the VREG_BYPASS bits of GPR registers should be cleared from default
value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
turned on.
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
---
drivers/pci/controller/dwc/pci-imx6.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 853ea8e82952..94b43b4ecca1 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -37,6 +37,7 @@
#define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
#define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN BIT(10)
#define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11)
+#define IMX8MQ_GPR_PCIE_VREG_BYPASS BIT(12)
#define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE GENMASK(11, 8)
#define IMX8MQ_PCIE2_BASE_ADDR 0x33c00000
@@ -80,6 +81,7 @@ struct imx6_pcie {
u32 tx_swing_full;
u32 tx_swing_low;
struct regulator *vpcie;
+ struct regulator *vph;
void __iomem *phy_base;
/* power domain for pcie */
@@ -621,6 +623,17 @@ static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
imx6_pcie_grp_offset(imx6_pcie),
IMX8MQ_GPR_PCIE_REF_USE_PAD,
IMX8MQ_GPR_PCIE_REF_USE_PAD);
+ /*
+ * Regarding the datasheet, the PCIE_VPH is suggested
+ * to be 1.8V. If the PCIE_VPH is supplied by 3.3V, the
+ * VREG_BYPASS should be cleared to zero.
+ */
+ if (imx6_pcie->vph &&
+ regulator_get_voltage(imx6_pcie->vph) > 3000000)
+ regmap_update_bits(imx6_pcie->iomuxc_gpr,
+ imx6_pcie_grp_offset(imx6_pcie),
+ IMX8MQ_GPR_PCIE_VREG_BYPASS,
+ 0);
break;
case IMX7D:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
@@ -1130,6 +1143,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)
imx6_pcie->vpcie = NULL;
}
+ imx6_pcie->vph = devm_regulator_get_optional(&pdev->dev, "vph");
+ if (IS_ERR(imx6_pcie->vph)) {
+ if (PTR_ERR(imx6_pcie->vph) != -ENODEV)
+ return PTR_ERR(imx6_pcie->vph);
+ imx6_pcie->vph = NULL;
+ }
+
platform_set_drvdata(pdev, imx6_pcie);
ret = imx6_pcie_attach_pd(dev);
--
2.17.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [RESEND v4 1/2] dt-bindings: imx6q-pcie: add one regulator used to power up pcie phy
2021-03-30 8:08 ` [RESEND v4 1/2] dt-bindings: imx6q-pcie: " Richard Zhu
@ 2021-05-06 16:08 ` Lucas Stach
2021-05-06 21:01 ` Bjorn Helgaas
0 siblings, 1 reply; 8+ messages in thread
From: Lucas Stach @ 2021-05-06 16:08 UTC (permalink / raw)
To: lorenzo.pieralisi
Cc: linux-pci, linux-imx, linux-arm-kernel, linux-kernel, kernel,
Richard Zhu, andrew.smirnov, shawnguo, kw, bhelgaas, stefan
Hi Lorenzo,
have those two patches fallen through some crack? AFAICS they are gone
from patchwork, but I also can't find them in any branch in the usual
git repos.
Regards,
Lucas
Am Dienstag, dem 30.03.2021 um 16:08 +0800 schrieb Richard Zhu:
> Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
> In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
> sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
> the VREG_BYPASS bits of GPR registers should be cleared from default
> value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
> turned on.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> index de4b2baf91e8..d8971ab99274 100644
> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> @@ -38,6 +38,9 @@ Optional properties:
> The regulator will be enabled when initializing the PCIe host and
> disabled either as part of the init process or when shutting down the
> host.
> +- vph-supply: Should specify the regulator in charge of VPH one of the three
> + PCIe PHY powers. This regulator can be supplied by both 1.8v and 3.3v voltage
> + supplies.
>
>
> Additional required properties for imx6sx-pcie:
> - clock names: Must include the following additional entries:
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RESEND v4 1/2] dt-bindings: imx6q-pcie: add one regulator used to power up pcie phy
2021-05-06 16:08 ` Lucas Stach
@ 2021-05-06 21:01 ` Bjorn Helgaas
2021-05-14 8:35 ` [EXT] " Richard Zhu
0 siblings, 1 reply; 8+ messages in thread
From: Bjorn Helgaas @ 2021-05-06 21:01 UTC (permalink / raw)
To: Lucas Stach
Cc: lorenzo.pieralisi, linux-pci, linux-imx, linux-arm-kernel,
linux-kernel, kernel, Richard Zhu, andrew.smirnov, shawnguo, kw,
bhelgaas, stefan
On Thu, May 06, 2021 at 06:08:24PM +0200, Lucas Stach wrote:
> Hi Lorenzo,
>
> have those two patches fallen through some crack? AFAICS they are gone
> from patchwork, but I also can't find them in any branch in the usual
> git repos.
They were marked "accepted" in patchwork but must have fallen through
the cracks. I reset them to "new" and assigned to Lorenzo.
Neither one follows the subject line capitalization conventions.
The subject line of this patch (1/2) doesn't really make sense. I
*think* this adds a property ("vph-supply") to indicate which
regulator supplys power to the PHY.
> Am Dienstag, dem 30.03.2021 um 16:08 +0800 schrieb Richard Zhu:
> > Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
> > In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
> > sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
> > the VREG_BYPASS bits of GPR registers should be cleared from default
> > value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
> > turned on.
This commit log doesn't describe the patch, either. Maybe something
like this:
dt-bindings: imx6q-pcie: Add "vph-supply" for PHY supply voltage
The i.MX8MQ PCIe PHY can use either a 1.8V or a 3.3V power supply.
Add a "vph-supply" property to indicate which regulator supplies
power for the PHY.
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> > ---
> > Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > index de4b2baf91e8..d8971ab99274 100644
> > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > @@ -38,6 +38,9 @@ Optional properties:
> > The regulator will be enabled when initializing the PCIe host and
> > disabled either as part of the init process or when shutting down the
> > host.
> > +- vph-supply: Should specify the regulator in charge of VPH one of the three
> > + PCIe PHY powers. This regulator can be supplied by both 1.8v and 3.3v voltage
> > + supplies.
Just going by examples for other drivers, I think this should say
something like this:
- vph-supply: Regulator for i.MX8MQ PCIe PHY. May supply either
1.8V or 3.3V.
You mentioned "one of the three PCIe PHY powers"; I don't know what
that means, so I don't know whether it's important to include.
I also don't know what "vph" means; if the "ph" is part of "phy", it'd
be nicer to include the "y", so it would be "vphy-supply".
> > Additional required properties for imx6sx-pcie:
> > - clock names: Must include the following additional entries:
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3
2021-03-30 8:08 ` [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3 Richard Zhu
@ 2021-05-06 21:09 ` Bjorn Helgaas
2021-05-14 8:36 ` [EXT] " Richard Zhu
0 siblings, 1 reply; 8+ messages in thread
From: Bjorn Helgaas @ 2021-05-06 21:09 UTC (permalink / raw)
To: Richard Zhu
Cc: l.stach, andrew.smirnov, shawnguo, kw, bhelgaas, stefan,
lorenzo.pieralisi, linux-pci, linux-imx, linux-arm-kernel,
linux-kernel, kernel
On Tue, Mar 30, 2021 at 04:08:21PM +0800, Richard Zhu wrote:
> Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
> In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
> sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
> the VREG_BYPASS bits of GPR registers should be cleared from default
> value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
> turned on.
Maybe something like this?
PCI: imx6: Enable PHY internal regulator when supplied >3V
The i.MX8MQ PCIe PHY needs 1.8V but can by supplied by either a 1.8V
or a 3.3V regulator.
The "vph-supply" DT property tells us which external regulator
supplies the PHY. If that regulator supplies anything over 3V,
enable the PHY's internal 3.3V-to-1.8V regulator.
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 853ea8e82952..94b43b4ecca1 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -37,6 +37,7 @@
> #define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
> #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN BIT(10)
> #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11)
> +#define IMX8MQ_GPR_PCIE_VREG_BYPASS BIT(12)
> #define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE GENMASK(11, 8)
> #define IMX8MQ_PCIE2_BASE_ADDR 0x33c00000
>
> @@ -80,6 +81,7 @@ struct imx6_pcie {
> u32 tx_swing_full;
> u32 tx_swing_low;
> struct regulator *vpcie;
> + struct regulator *vph;
> void __iomem *phy_base;
>
> /* power domain for pcie */
> @@ -621,6 +623,17 @@ static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
> imx6_pcie_grp_offset(imx6_pcie),
> IMX8MQ_GPR_PCIE_REF_USE_PAD,
> IMX8MQ_GPR_PCIE_REF_USE_PAD);
> + /*
> + * Regarding the datasheet, the PCIE_VPH is suggested
> + * to be 1.8V. If the PCIE_VPH is supplied by 3.3V, the
> + * VREG_BYPASS should be cleared to zero.
> + */
> + if (imx6_pcie->vph &&
> + regulator_get_voltage(imx6_pcie->vph) > 3000000)
> + regmap_update_bits(imx6_pcie->iomuxc_gpr,
> + imx6_pcie_grp_offset(imx6_pcie),
> + IMX8MQ_GPR_PCIE_VREG_BYPASS,
> + 0);
> break;
> case IMX7D:
> regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> @@ -1130,6 +1143,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> imx6_pcie->vpcie = NULL;
> }
>
> + imx6_pcie->vph = devm_regulator_get_optional(&pdev->dev, "vph");
> + if (IS_ERR(imx6_pcie->vph)) {
> + if (PTR_ERR(imx6_pcie->vph) != -ENODEV)
> + return PTR_ERR(imx6_pcie->vph);
> + imx6_pcie->vph = NULL;
> + }
> +
> platform_set_drvdata(pdev, imx6_pcie);
>
> ret = imx6_pcie_attach_pd(dev);
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [EXT] Re: [RESEND v4 1/2] dt-bindings: imx6q-pcie: add one regulator used to power up pcie phy
2021-05-06 21:01 ` Bjorn Helgaas
@ 2021-05-14 8:35 ` Richard Zhu
0 siblings, 0 replies; 8+ messages in thread
From: Richard Zhu @ 2021-05-14 8:35 UTC (permalink / raw)
To: Bjorn Helgaas, Lucas Stach
Cc: lorenzo.pieralisi, linux-pci, dl-linux-imx, linux-arm-kernel,
linux-kernel, kernel, andrew.smirnov, shawnguo, kw, bhelgaas,
stefan
Hi Bjorn:
It seems that the email I replied on May07, is missing.
Re-send it again.
Best Regards
Richard Zhu
> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: Friday, May 7, 2021 5:01 AM
> To: Lucas Stach <l.stach@pengutronix.de>
> Cc: lorenzo.pieralisi@arm.com; linux-pci@vger.kernel.org; dl-linux-imx
> <linux-imx@nxp.com>; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org; kernel@pengutronix.de; Richard Zhu
> <hongxing.zhu@nxp.com>; andrew.smirnov@gmail.com;
> shawnguo@kernel.org; kw@linux.com; bhelgaas@google.com;
> stefan@agner.ch
> Subject: [EXT] Re: [RESEND v4 1/2] dt-bindings: imx6q-pcie: add one
> regulator used to power up pcie phy
> On Thu, May 06, 2021 at 06:08:24PM +0200, Lucas Stach wrote:
> > Hi Lorenzo,
> >
> > have those two patches fallen through some crack? AFAICS they are gone
> > from patchwork, but I also can't find them in any branch in the usual
> > git repos.
>
> They were marked "accepted" in patchwork but must have fallen through the
> cracks. I reset them to "new" and assigned to Lorenzo.
>
> Neither one follows the subject line capitalization conventions.
>
> The subject line of this patch (1/2) doesn't really make sense. I
> *think* this adds a property ("vph-supply") to indicate which regulator supplys
> power to the PHY.
>
> > Am Dienstag, dem 30.03.2021 um 16:08 +0800 schrieb Richard Zhu:
> > > Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
> > > In default, the PCIE_VPH voltage is suggested to be 1.8v refer to
> > > data sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic
> > > design, the VREG_BYPASS bits of GPR registers should be cleared from
> > > default value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator
> > > would be turned on.
>
> This commit log doesn't describe the patch, either. Maybe something like
> this:
>
> dt-bindings: imx6q-pcie: Add "vph-supply" for PHY supply voltage
>
> The i.MX8MQ PCIe PHY can use either a 1.8V or a 3.3V power supply.
> Add a "vph-supply" property to indicate which regulator supplies
> power for the PHY.
>
[Richard Zhu] I'm fine with this one.
> > > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > > Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> > > ---
> > > Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > > b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > > index de4b2baf91e8..d8971ab99274 100644
> > > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> > > @@ -38,6 +38,9 @@ Optional properties:
> > > The regulator will be enabled when initializing the PCIe host and
> > > disabled either as part of the init process or when shutting down the
> > > host.
> > > +- vph-supply: Should specify the regulator in charge of VPH one of
> > > +the three
> > > + PCIe PHY powers. This regulator can be supplied by both 1.8v and
> > > +3.3v voltage
> > > + supplies.
>
> Just going by examples for other drivers, I think this should say something like
> this:
>
> - vph-supply: Regulator for i.MX8MQ PCIe PHY. May supply either
> 1.8V or 3.3V.
>
> You mentioned "one of the three PCIe PHY powers"; I don't know what that
> means, so I don't know whether it's important to include.
>
> I also don't know what "vph" means; if the "ph" is part of "phy", it'd be nicer
> to include the "y", so it would be "vphy-supply".
>
[Richard Zhu] There are three power supplies in total required by the PHY.
- vp: PHY analog and digital supply
- vptxN: PHY transmit supply
-vph: High-voltage power supply.
Only vph is handled by SW here.
BR
Richard
> > > Additional required properties for imx6sx-pcie:
> > > - clock names: Must include the following additional entries:
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [EXT] Re: [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3
2021-05-06 21:09 ` Bjorn Helgaas
@ 2021-05-14 8:36 ` Richard Zhu
0 siblings, 0 replies; 8+ messages in thread
From: Richard Zhu @ 2021-05-14 8:36 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: l.stach, andrew.smirnov, shawnguo, kw, bhelgaas, stefan,
lorenzo.pieralisi, linux-pci, dl-linux-imx, linux-arm-kernel,
linux-kernel, kernel
Hi Bjorn:
It seems that the email I replied on May07, is missing.
Re-send it.
Best Regards
Richard Zhu
> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: Friday, May 7, 2021 5:09 AM
> To: Richard Zhu <hongxing.zhu@nxp.com>
> Cc: l.stach@pengutronix.de; andrew.smirnov@gmail.com;
> shawnguo@kernel.org; kw@linux.com; bhelgaas@google.com;
> stefan@agner.ch; lorenzo.pieralisi@arm.com; linux-pci@vger.kernel.org;
> dl-linux-imx <linux-imx@nxp.com>; linux-arm-kernel@lists.infradead.org;
> linux-kernel@vger.kernel.org; kernel@pengutronix.de
> Subject: [EXT] Re: [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph
> voltage is 3v3
>
> Caution: EXT Email
>
> On Tue, Mar 30, 2021 at 04:08:21PM +0800, Richard Zhu wrote:
> > Both 1.8v and 3.3v power supplies can be used by i.MX8MQ PCIe PHY.
> > In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
> > sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
> > the VREG_BYPASS bits of GPR registers should be cleared from default
> > value 1b'1 to 1b'0. Thus, the internal 3v3 to 1v8 translator would be
> > turned on.
>
> Maybe something like this?
>
> PCI: imx6: Enable PHY internal regulator when supplied >3V
>
> The i.MX8MQ PCIe PHY needs 1.8V but can by supplied by either a 1.8V
> or a 3.3V regulator.
>
> The "vph-supply" DT property tells us which external regulator
> supplies the PHY. If that regulator supplies anything over 3V,
> enable the PHY's internal 3.3V-to-1.8V regulator.
>
[Richard Zhu] Hi Bjorn:
Thanks for your comments.
vph is the "high-voltage power supply" of the PHY.
How do you think with the following one with some minor updates?
PCI: imx6: Enable PHY internal regulator when supplied >3V
The i.MX8MQ PCIe PHY needs 1.8V in default but can be supplied by
either a 1.8V or a 3.3V regulator.
The "vph-supply" DT property tells us which external regulator
supplies the PHY. If that regulator supplies anything over 3V,
enable the PHY's internal 3.3V-to-1.8V regulator.
BR
Richard
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> > ---
> > drivers/pci/controller/dwc/pci-imx6.c | 20 ++++++++++++++++++++
> > 1 file changed, 20 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 853ea8e82952..94b43b4ecca1 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -37,6 +37,7 @@
> > #define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
> > #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE_EN BIT(10)
> > #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11)
> > +#define IMX8MQ_GPR_PCIE_VREG_BYPASS BIT(12)
> > #define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE GENMASK(11, 8)
> > #define IMX8MQ_PCIE2_BASE_ADDR
> 0x33c00000
> >
> > @@ -80,6 +81,7 @@ struct imx6_pcie {
> > u32 tx_swing_full;
> > u32 tx_swing_low;
> > struct regulator *vpcie;
> > + struct regulator *vph;
> > void __iomem *phy_base;
> >
> > /* power domain for pcie */
> > @@ -621,6 +623,17 @@ static void imx6_pcie_init_phy(struct imx6_pcie
> *imx6_pcie)
> > imx6_pcie_grp_offset(imx6_pcie),
> >
> IMX8MQ_GPR_PCIE_REF_USE_PAD,
> >
> IMX8MQ_GPR_PCIE_REF_USE_PAD);
> > + /*
> > + * Regarding the datasheet, the PCIE_VPH is suggested
> > + * to be 1.8V. If the PCIE_VPH is supplied by 3.3V, the
> > + * VREG_BYPASS should be cleared to zero.
> > + */
> > + if (imx6_pcie->vph &&
> > + regulator_get_voltage(imx6_pcie->vph) > 3000000)
> > + regmap_update_bits(imx6_pcie->iomuxc_gpr,
> > +
> imx6_pcie_grp_offset(imx6_pcie),
> > +
> IMX8MQ_GPR_PCIE_VREG_BYPASS,
> > + 0);
> > break;
> > case IMX7D:
> > regmap_update_bits(imx6_pcie->iomuxc_gpr,
> IOMUXC_GPR12,
> > @@ -1130,6 +1143,13 @@ static int imx6_pcie_probe(struct
> platform_device *pdev)
> > imx6_pcie->vpcie = NULL;
> > }
> >
> > + imx6_pcie->vph = devm_regulator_get_optional(&pdev->dev,
> "vph");
> > + if (IS_ERR(imx6_pcie->vph)) {
> > + if (PTR_ERR(imx6_pcie->vph) != -ENODEV)
> > + return PTR_ERR(imx6_pcie->vph);
> > + imx6_pcie->vph = NULL;
> > + }
> > +
> > platform_set_drvdata(pdev, imx6_pcie);
> >
> > ret = imx6_pcie_attach_pd(dev);
> > --
> > 2.17.1
> >
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-05-14 8:37 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-30 8:08 [RESEND v4 0/2] add one regulator used to power up pcie phy Richard Zhu
2021-03-30 8:08 ` [RESEND v4 1/2] dt-bindings: imx6q-pcie: " Richard Zhu
2021-05-06 16:08 ` Lucas Stach
2021-05-06 21:01 ` Bjorn Helgaas
2021-05-14 8:35 ` [EXT] " Richard Zhu
2021-03-30 8:08 ` [RESEND v4 2/2] PCI: imx: clear vreg bypass when pcie vph voltage is 3v3 Richard Zhu
2021-05-06 21:09 ` Bjorn Helgaas
2021-05-14 8:36 ` [EXT] " Richard Zhu
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