diff mbox series

[RFC] USB: host: ehci-atmel: Allow enabling HSIC on SAMA5D2

Message ID 20210824063702.24586-1-ada@thorsis.com (mailing list archive)
State New, archived
Headers show
Series [RFC] USB: host: ehci-atmel: Allow enabling HSIC on SAMA5D2 | expand

Commit Message

Alexander Dahl Aug. 24, 2021, 6:37 a.m. UTC 
Unlike other SoC series featuring the 'atmel,at91sam9g45-ehci' USB EHCI
controller, which have embedded USB high-speed transceivers for each
port, the third port on the SAMA5D2 series is HSIC only.  That HSIC
interface is not enabled after a power-on reset, but can be enabled by
setting a flag in a vendor specific EHCI register.

The register offsets added to the new header file were compared with
those for the SAM9G45, SAM9X25, SAMA5D3, SAMA5D4, and SAM9X60 series and
there are no differences in the offsets or contents of those registers.
Which of those additional vendor specific registers are supported,
differs by SoC family.  So while the HSIC enable feature is currently
only present for SAMA5D2, it probably does not hurt to set it on the
other families, hence no additional check for SoC family here.

Tested on a custom board featuring a SAMA5D27C-D5M SiP connected to an
USB3503 hub with an upstream HSIC interface.

Link: https://community.atmel.com/forum/sama5d2-using-hsic-under-linux
Signed-off-by: Alexander Dahl <ada@thorsis.com>
---

Notes:
    - for introducing new dt binding, would be nice to convert old one
      first, probably needs split up and multiple iteration review?
    - name of that new dt property?
    - register definitions put to a separate file, like
      'drivers/usb/host/ehci-fsl.h'
    - unsure where exactly in the probe process that register write should
      happen, datasheet gives no hint
    - should suspend/resume be considered?

 drivers/usb/host/ehci-atmel.c | 17 +++++++++++++++++
 drivers/usb/host/ehci-atmel.h | 19 +++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 drivers/usb/host/ehci-atmel.h


base-commit: e22ce8eb631bdc47a4a4ea7ecf4e4ba499db4f93

Comments

Greg Kroah-Hartman Aug. 24, 2021, 6:45 a.m. UTC | #1 
On Tue, Aug 24, 2021 at 08:37:02AM +0200, Alexander Dahl wrote:
> Unlike other SoC series featuring the 'atmel,at91sam9g45-ehci' USB EHCI
> controller, which have embedded USB high-speed transceivers for each
> port, the third port on the SAMA5D2 series is HSIC only.  That HSIC
> interface is not enabled after a power-on reset, but can be enabled by
> setting a flag in a vendor specific EHCI register.
> 
> The register offsets added to the new header file were compared with
> those for the SAM9G45, SAM9X25, SAMA5D3, SAMA5D4, and SAM9X60 series and
> there are no differences in the offsets or contents of those registers.
> Which of those additional vendor specific registers are supported,
> differs by SoC family.  So while the HSIC enable feature is currently
> only present for SAMA5D2, it probably does not hurt to set it on the
> other families, hence no additional check for SoC family here.
> 
> Tested on a custom board featuring a SAMA5D27C-D5M SiP connected to an
> USB3503 hub with an upstream HSIC interface.
> 
> Link: https://community.atmel.com/forum/sama5d2-using-hsic-under-linux
> Signed-off-by: Alexander Dahl <ada@thorsis.com>
> ---
> 
> Notes:
>     - for introducing new dt binding, would be nice to convert old one
>       first, probably needs split up and multiple iteration review?
>     - name of that new dt property?
>     - register definitions put to a separate file, like
>       'drivers/usb/host/ehci-fsl.h'
>     - unsure where exactly in the probe process that register write should
>       happen, datasheet gives no hint
>     - should suspend/resume be considered?
> 
>  drivers/usb/host/ehci-atmel.c | 17 +++++++++++++++++
>  drivers/usb/host/ehci-atmel.h | 19 +++++++++++++++++++

No need for a new .h file that is only used in a single .c file.  Just
put those few lines in the .c file please.

thanks,

greg k-h
Nicolas Ferre Sept. 2, 2021, 3:33 p.m. UTC | #2 
Hi Alexander,

On 24/08/2021 at 08:37, Alexander Dahl wrote:
> Unlike other SoC series featuring the 'atmel,at91sam9g45-ehci' USB EHCI
> controller, which have embedded USB high-speed transceivers for each
> port, the third port on the SAMA5D2 series is HSIC only.  That HSIC
> interface is not enabled after a power-on reset, but can be enabled by
> setting a flag in a vendor specific EHCI register.
> 
> The register offsets added to the new header file were compared with
> those for the SAM9G45, SAM9X25, SAMA5D3, SAMA5D4, and SAM9X60 series and
> there are no differences in the offsets or contents of those registers.
> Which of those additional vendor specific registers are supported,
> differs by SoC family.  So while the HSIC enable feature is currently
> only present for SAMA5D2, it probably does not hurt to set it on the
> other families, hence no additional check for SoC family here.
> 
> Tested on a custom board featuring a SAMA5D27C-D5M SiP connected to an
> USB3503 hub with an upstream HSIC interface.
> 
> Link: https://community.atmel.com/forum/sama5d2-using-hsic-under-linux
> Signed-off-by: Alexander Dahl <ada@thorsis.com>

Sorry for not having coming back to you earlier, summertime...

What you are looking for is what Cristian developed in our "vendor tree" 
and that needs to be "Mainlined":
https://github.com/linux4sam/linux-at91/commit/ca368f544899c14b03df9ce7510684f03acf1bf9

It allows us to have a gigabit Ethernet HSIC connected on our sama5d2 
ICP board. It works well for some time.

For DT, we rely on the standard "phy_type" property set to "hsic" as 
highlighted in this DT node on the ICP board precisely:
https://github.com/linux4sam/linux-at91/blob/master/arch/arm/boot/dts/at91-sama5d2_icp.dts#L766

This way we can use the of_usb_get_phy_mode() standard function:
https://github.com/linux4sam/linux-at91/blob/master/drivers/usb/phy/of.c#L28

All this tells me that I would prefer Cristi's approach. If agreed, 
we'll make sure to make progress on the mainlining part soon.

Hope that it helps. Best regards,
   Nicolas

> ---
> 
> Notes:
>      - for introducing new dt binding, would be nice to convert old one
>        first, probably needs split up and multiple iteration review?
>      - name of that new dt property?
>      - register definitions put to a separate file, like
>        'drivers/usb/host/ehci-fsl.h'
>      - unsure where exactly in the probe process that register write should
>        happen, datasheet gives no hint
>      - should suspend/resume be considered?
> 
>   drivers/usb/host/ehci-atmel.c | 17 +++++++++++++++++
>   drivers/usb/host/ehci-atmel.h | 19 +++++++++++++++++++
>   2 files changed, 36 insertions(+)
>   create mode 100644 drivers/usb/host/ehci-atmel.h
> 
> diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
> index e893467d659c..f8d9e686c082 100644
> --- a/drivers/usb/host/ehci-atmel.c
> +++ b/drivers/usb/host/ehci-atmel.c
> @@ -20,6 +20,7 @@
>   #include <linux/usb/hcd.h>
> 
>   #include "ehci.h"
> +#include "ehci-atmel.h"
> 
>   #define DRIVER_DESC "EHCI Atmel driver"
> 
> @@ -85,6 +86,7 @@ static void atmel_stop_ehci(struct platform_device *pdev)
> 
>   static int ehci_atmel_drv_probe(struct platform_device *pdev)
>   {
> +       struct device_node *np = pdev->dev.of_node;
>          struct usb_hcd *hcd;
>          const struct hc_driver *driver = &ehci_atmel_hc_driver;
>          struct resource *res;
> @@ -149,6 +151,14 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
> 
>          atmel_start_ehci(pdev);
> 
> +       if (of_property_read_bool(np, "atmel,enable-hsic")) {
> +               u32 tmp;
> +
> +               tmp = ehci_readl(ehci, hcd->regs + AT91_UHPHS_INSNREG08);
> +               tmp |= AT91_UHPHS_HSIC_EN;
> +               ehci_writel(ehci, tmp, hcd->regs + AT91_UHPHS_INSNREG08);
> +       }
> +
>          retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
>          if (retval)
>                  goto fail_add_hcd;
> @@ -170,10 +180,17 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
>   static int ehci_atmel_drv_remove(struct platform_device *pdev)
>   {
>          struct usb_hcd *hcd = platform_get_drvdata(pdev);
> +       struct ehci_hcd *ehci;
> +       u32 tmp;
> 
>          usb_remove_hcd(hcd);
>          usb_put_hcd(hcd);
> 
> +       ehci = hcd_to_ehci(hcd);
> +       tmp = ehci_readl(ehci, hcd->regs + AT91_UHPHS_INSNREG08);
> +       tmp &= ~AT91_UHPHS_HSIC_EN;
> +       ehci_writel(ehci, tmp, hcd->regs + AT91_UHPHS_INSNREG08);
> +
>          atmel_stop_ehci(pdev);
> 
>          return 0;
> diff --git a/drivers/usb/host/ehci-atmel.h b/drivers/usb/host/ehci-atmel.h
> new file mode 100644
> index 000000000000..4c4998c2a6dd
> --- /dev/null
> +++ b/drivers/usb/host/ehci-atmel.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Vendor specific definitions for EHCI on Atmel/Microchip SoCs.
> + *
> + * © 2021 Alexander Dahl <ada@thorsis.com>
> + */
> +#ifndef EHCI_ATMEL_H
> +#define EHCI_ATMEL_H
> +
> +/* device specific register offsets, taken from SAMA5D2 datasheet */
> +
> +#define AT91_UHPHS_INSNREG06    0xA8        /* AHB Error Status Register */
> +
> +#define AT91_UHPHS_INSNREG07    0xAC        /* AHB Master Error Address Register */
> +
> +#define AT91_UHPHS_INSNREG08    0xB0        /* HSIC Enable/Disable Register */
> +#define AT91_UHPHS_HSIC_EN      (1 << 2)    /* HSIC Enable/Disable */
> +
> +#endif /* ECHI_ATMEL_H */
> 
> base-commit: e22ce8eb631bdc47a4a4ea7ecf4e4ba499db4f93
> --
> 2.30.2
>
Alexander Dahl Sept. 6, 2021, 7:20 a.m. UTC | #3 
Hello Nicolas,

Am Donnerstag, 2. September 2021, 17:33:50 CEST schrieb Nicolas Ferre:
> Hi Alexander,
> 
> On 24/08/2021 at 08:37, Alexander Dahl wrote:
> > Unlike other SoC series featuring the 'atmel,at91sam9g45-ehci' USB EHCI
> > controller, which have embedded USB high-speed transceivers for each
> > port, the third port on the SAMA5D2 series is HSIC only.  That HSIC
> > interface is not enabled after a power-on reset, but can be enabled by
> > setting a flag in a vendor specific EHCI register.
> > 
> > The register offsets added to the new header file were compared with
> > those for the SAM9G45, SAM9X25, SAMA5D3, SAMA5D4, and SAM9X60 series and
> > there are no differences in the offsets or contents of those registers.
> > Which of those additional vendor specific registers are supported,
> > differs by SoC family.  So while the HSIC enable feature is currently
> > only present for SAMA5D2, it probably does not hurt to set it on the
> > other families, hence no additional check for SoC family here.
> > 
> > Tested on a custom board featuring a SAMA5D27C-D5M SiP connected to an
> > USB3503 hub with an upstream HSIC interface.
> > 
> > Link: https://community.atmel.com/forum/sama5d2-using-hsic-under-linux
> > Signed-off-by: Alexander Dahl <ada@thorsis.com>
> 
> Sorry for not having coming back to you earlier, summertime...

I had one week off last week due to a mild infection myself, so we just 
proceed here and now. (-:

> What you are looking for is what Cristian developed in our "vendor tree"
> and that needs to be "Mainlined":
> https://github.com/linux4sam/linux-at91/commit/ca368f544899c14b03df9ce751068
> 4f03acf1bf9

Looks like it does what it should from quick code inspection. One could 
nitpick some things, maybe I add some comments on GitHub.

> It allows us to have a gigabit Ethernet HSIC connected on our sama5d2
> ICP board. It works well for some time.

Good to hear.

> For DT, we rely on the standard "phy_type" property set to "hsic" as
> highlighted in this DT node on the ICP board precisely:
> https://github.com/linux4sam/linux-at91/blob/master/arch/arm/boot/dts/at91-s
> ama5d2_icp.dts#L766
> 
> This way we can use the of_usb_get_phy_mode() standard function:
> https://github.com/linux4sam/linux-at91/blob/master/drivers/usb/phy/of.c#L28

I noticed that phy_type property, but did not follow that approach, because 
that USB block in SAMA5D2 has three ports, where one (A) is shared with a 
device port, two (A and B) have embedded transceivers, and only the third (C) 
has that HSIC interface, but nothing else. So the flag has no effect on port A 
and B anyways, and I would have found it misleading to set phy_type to HSIC 
for the whole USB block.

> All this tells me that I would prefer Cristi's approach. If agreed,
> we'll make sure to make progress on the mainlining part soon.

I don't mind. If that's your preferred approach, I will happily test it. Was 
the series already posted to upstream?

> Hope that it helps. Best regards,
>    Nicolas

Yes, indeed. Thanks for your feedback.

Greets
Alex

> 
> > ---
> > 
> > Notes:
> >      - for introducing new dt binding, would be nice to convert old one
> >      
> >        first, probably needs split up and multiple iteration review?
> >      
> >      - name of that new dt property?
> >      - register definitions put to a separate file, like
> >      
> >        'drivers/usb/host/ehci-fsl.h'
> >      
> >      - unsure where exactly in the probe process that register write
> >      should
> >      
> >        happen, datasheet gives no hint
> >      
> >      - should suspend/resume be considered?
> >   
> >   drivers/usb/host/ehci-atmel.c | 17 +++++++++++++++++
> >   drivers/usb/host/ehci-atmel.h | 19 +++++++++++++++++++
> >   2 files changed, 36 insertions(+)
> >   create mode 100644 drivers/usb/host/ehci-atmel.h
> > 
> > diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
> > index e893467d659c..f8d9e686c082 100644
> > --- a/drivers/usb/host/ehci-atmel.c
> > +++ b/drivers/usb/host/ehci-atmel.c
> > @@ -20,6 +20,7 @@
> > 
> >   #include <linux/usb/hcd.h>
> >   
> >   #include "ehci.h"
> > 
> > +#include "ehci-atmel.h"
> > 
> >   #define DRIVER_DESC "EHCI Atmel driver"
> > 
> > @@ -85,6 +86,7 @@ static void atmel_stop_ehci(struct platform_device
> > *pdev)
> > 
> >   static int ehci_atmel_drv_probe(struct platform_device *pdev)
> >   {
> > 
> > +       struct device_node *np = pdev->dev.of_node;
> > 
> >          struct usb_hcd *hcd;
> >          const struct hc_driver *driver = &ehci_atmel_hc_driver;
> >          struct resource *res;
> > 
> > @@ -149,6 +151,14 @@ static int ehci_atmel_drv_probe(struct
> > platform_device *pdev)> 
> >          atmel_start_ehci(pdev);
> > 
> > +       if (of_property_read_bool(np, "atmel,enable-hsic")) {
> > +               u32 tmp;
> > +
> > +               tmp = ehci_readl(ehci, hcd->regs + AT91_UHPHS_INSNREG08);
> > +               tmp |= AT91_UHPHS_HSIC_EN;
> > +               ehci_writel(ehci, tmp, hcd->regs + AT91_UHPHS_INSNREG08);
> > +       }
> > +
> > 
> >          retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
> >          if (retval)
> >          
> >                  goto fail_add_hcd;
> > 
> > @@ -170,10 +180,17 @@ static int ehci_atmel_drv_probe(struct
> > platform_device *pdev)> 
> >   static int ehci_atmel_drv_remove(struct platform_device *pdev)
> >   {
> >   
> >          struct usb_hcd *hcd = platform_get_drvdata(pdev);
> > 
> > +       struct ehci_hcd *ehci;
> > +       u32 tmp;
> > 
> >          usb_remove_hcd(hcd);
> >          usb_put_hcd(hcd);
> > 
> > +       ehci = hcd_to_ehci(hcd);
> > +       tmp = ehci_readl(ehci, hcd->regs + AT91_UHPHS_INSNREG08);
> > +       tmp &= ~AT91_UHPHS_HSIC_EN;
> > +       ehci_writel(ehci, tmp, hcd->regs + AT91_UHPHS_INSNREG08);
> > +
> > 
> >          atmel_stop_ehci(pdev);
> >          
> >          return 0;
> > 
> > diff --git a/drivers/usb/host/ehci-atmel.h b/drivers/usb/host/ehci-atmel.h
> > new file mode 100644
> > index 000000000000..4c4998c2a6dd
> > --- /dev/null
> > +++ b/drivers/usb/host/ehci-atmel.h
> > @@ -0,0 +1,19 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Vendor specific definitions for EHCI on Atmel/Microchip SoCs.
> > + *
> > + * © 2021 Alexander Dahl <ada@thorsis.com>
> > + */
> > +#ifndef EHCI_ATMEL_H
> > +#define EHCI_ATMEL_H
> > +
> > +/* device specific register offsets, taken from SAMA5D2 datasheet */
> > +
> > +#define AT91_UHPHS_INSNREG06    0xA8        /* AHB Error Status Register
> > */ +
> > +#define AT91_UHPHS_INSNREG07    0xAC        /* AHB Master Error Address
> > Register */ +
> > +#define AT91_UHPHS_INSNREG08    0xB0        /* HSIC Enable/Disable
> > Register */ +#define AT91_UHPHS_HSIC_EN      (1 << 2)    /* HSIC
> > Enable/Disable */ +
> > +#endif /* ECHI_ATMEL_H */
> > 
> > base-commit: e22ce8eb631bdc47a4a4ea7ecf4e4ba499db4f93
> > --
> > 2.30.2
diff mbox series

Patch

diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index e893467d659c..f8d9e686c082 100644
--- a/drivers/usb/host/ehci-atmel.c
+++ b/drivers/usb/host/ehci-atmel.c
@@ -20,6 +20,7 @@ 
 #include <linux/usb/hcd.h>
 
 #include "ehci.h"
+#include "ehci-atmel.h"
 
 #define DRIVER_DESC "EHCI Atmel driver"
 
@@ -85,6 +86,7 @@  static void atmel_stop_ehci(struct platform_device *pdev)
 
 static int ehci_atmel_drv_probe(struct platform_device *pdev)
 {
+	struct device_node *np = pdev->dev.of_node;
 	struct usb_hcd *hcd;
 	const struct hc_driver *driver = &ehci_atmel_hc_driver;
 	struct resource *res;
@@ -149,6 +151,14 @@  static int ehci_atmel_drv_probe(struct platform_device *pdev)
 
 	atmel_start_ehci(pdev);
 
+	if (of_property_read_bool(np, "atmel,enable-hsic")) {
+		u32 tmp;
+
+		tmp = ehci_readl(ehci, hcd->regs + AT91_UHPHS_INSNREG08);
+		tmp |= AT91_UHPHS_HSIC_EN;
+		ehci_writel(ehci, tmp, hcd->regs + AT91_UHPHS_INSNREG08);
+	}
+
 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (retval)
 		goto fail_add_hcd;
@@ -170,10 +180,17 @@  static int ehci_atmel_drv_probe(struct platform_device *pdev)
 static int ehci_atmel_drv_remove(struct platform_device *pdev)
 {
 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+	struct ehci_hcd *ehci;
+	u32 tmp;
 
 	usb_remove_hcd(hcd);
 	usb_put_hcd(hcd);
 
+	ehci = hcd_to_ehci(hcd);
+	tmp = ehci_readl(ehci, hcd->regs + AT91_UHPHS_INSNREG08);
+	tmp &= ~AT91_UHPHS_HSIC_EN;
+	ehci_writel(ehci, tmp, hcd->regs + AT91_UHPHS_INSNREG08);
+
 	atmel_stop_ehci(pdev);
 
 	return 0;
diff --git a/drivers/usb/host/ehci-atmel.h b/drivers/usb/host/ehci-atmel.h
new file mode 100644
index 000000000000..4c4998c2a6dd
--- /dev/null
+++ b/drivers/usb/host/ehci-atmel.h
@@ -0,0 +1,19 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Vendor specific definitions for EHCI on Atmel/Microchip SoCs.
+ *
+ * © 2021 Alexander Dahl <ada@thorsis.com>
+ */
+#ifndef EHCI_ATMEL_H
+#define EHCI_ATMEL_H
+
+/* device specific register offsets, taken from SAMA5D2 datasheet */
+
+#define AT91_UHPHS_INSNREG06    0xA8        /* AHB Error Status Register */
+
+#define AT91_UHPHS_INSNREG07    0xAC        /* AHB Master Error Address Register */
+
+#define AT91_UHPHS_INSNREG08    0xB0        /* HSIC Enable/Disable Register */
+#define AT91_UHPHS_HSIC_EN      (1 << 2)    /* HSIC Enable/Disable */
+
+#endif /* ECHI_ATMEL_H */