| Message ID | 1498631315-15730-1-git-send-email-yoshihiro.shimoda.uh@renesas.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Stephen Boyd |
| Headers | show |
Hi Simoda-san, On Wed, Jun 28, 2017 at 8:28 AM, Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> wrote: > R-Car USB 2.0 controller can change the clock source from an oscillator > to an external clock via a register. So, this patch adds support > the clock source selector as a clock driver. > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Thanks for your patch! > --- /dev/null > +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c > +static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv) > +{ > + u16 val = readw(priv->base + USB20_CLKSET0); > + > + pr_debug("%s: enter %d %d %x\n", __func__, > + priv->extal, priv->xtal, val); > + > + if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY) > + writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0); > +} > + > +static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv) > +{ > + if (priv->extal && !priv->xtal) > + writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0); > +} > + > +static int usb2_clock_sel_enable(struct clk_hw *hw) > +{ > + usb2_clock_sel_enable_extal_only(to_priv(hw)); > + > + return 0; > +} > + > +static void usb2_clock_sel_disable(struct clk_hw *hw) > +{ > + usb2_clock_sel_disable_extal_only(to_priv(hw)); > +} > + > +/* > + * This module seems a mux, but this driver assumes a gate because > + * ehci/ohci platform drivers don't support clk_set_parent() for now. > + * If this driver acts as a gate, ehci/ohci-platform drivers don't need > + * any modification. > + */ > +static const struct clk_ops usb2_clock_sel_clock_ops = { > + .enable = usb2_clock_sel_enable, > + .disable = usb2_clock_sel_disable, > +}; So you do "smart muxing" in the enable routine above? > +static int __init rcar_usb2_clock_sel_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct usb2_clock_sel_priv *priv; > + struct resource *res; > + struct clk *clk; > + struct clk_init_data init; > + int error; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + priv->base = devm_ioremap_resource(dev, res); > + if (IS_ERR(priv->base)) > + return PTR_ERR(priv->base); > + > + priv->ehci_clk = devm_clk_get(dev, "ehci_ohci"); > + if (!IS_ERR(priv->ehci_clk)) { > + error = clk_prepare_enable(priv->ehci_clk); > + if (error) > + return error; > + } > + > + clk = devm_clk_get(dev, "usb_extal"); > + if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { > + priv->extal = !!clk_get_rate(clk); > + clk_disable_unprepare(clk); > + } > + clk = devm_clk_get(dev, "usb_xtal"); > + if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { > + priv->xtal = !!clk_get_rate(clk); > + clk_disable_unprepare(clk); > + } > + > + if (!priv->extal && !priv->extal) { > + dev_err(dev, "This driver needs usb_extal or usb_xtal\n"); > + return -ENOENT; Perhaps enabled clocks should be disabled on error? > + } > + > + platform_set_drvdata(pdev, priv); > + dev_set_drvdata(dev, priv); > + > + init.name = "rcar_usb2_clock_sel"; > + init.ops = &usb2_clock_sel_clock_ops; > + init.flags = CLK_IS_BASIC; > + init.parent_names = NULL; > + init.num_parents = 0; > + priv->hw.init = &init; > + > + clk = clk_register(NULL, &priv->hw); > + if (IS_ERR(clk)) > + return PTR_ERR(clk); Likewise. > + error = of_clk_add_provider(np, of_clk_src_simple_get, clk); > + if (error) > + return error; > + > + return 0; return of_clk_add_provider(np, of_clk_src_simple_get, clk); > +/* Since this driver needs other ccf drivers, this uses subsys_initcall_sync */ > +subsys_initcall_sync(rcar_usb2_clock_sel_init); I suppose this is a workaround for the lack of probe deferral support in the USB subsystem? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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Hi Shimoda-san, On Wed, Jul 5, 2017 at 1:57 PM, Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> wrote: >> From: Geert Uytterhoeven >> Sent: Wednesday, July 5, 2017 7:09 PM >> On Wed, Jun 28, 2017 at 8:28 AM, Yoshihiro Shimoda >> <yoshihiro.shimoda.uh@renesas.com> wrote: >> > R-Car USB 2.0 controller can change the clock source from an oscillator >> > to an external clock via a register. So, this patch adds support >> > the clock source selector as a clock driver. >> > --- /dev/null >> > +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c >> > +/* Since this driver needs other ccf drivers, this uses subsys_initcall_sync */ >> > +subsys_initcall_sync(rcar_usb2_clock_sel_init); >> >> I suppose this is a workaround for the lack of probe deferral support in the >> USB subsystem? > > This is my fault. I added "power-domains" property into this device's node. > After I remove the power-domains like the cpg node, this driver can use subsys_initcall() > instead of subsys_initcall_sync(). Does the clock sel module requires the functional clock "ehci_ohci" to be running before you can access its registers? If yes, I think there should be a "power-domains" property. Then, you can simplify the code by calling pm_runtime_enable(dev); pm_runtime_get_sync(dev); and remove the explicit handling of the functional clock. That does not solve probe deferral handling in the USB subsystem, though. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jun 28, 2017 at 03:28:35PM +0900, Yoshihiro Shimoda wrote: > R-Car USB 2.0 controller can change the clock source from an oscillator > to an external clock via a register. So, this patch adds support > the clock source selector as a clock driver. > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > --- > This patch is based on the renesas-drivers.git / > renesas-drivers-2017-06-27-v4.12-rc7 tag. > > Changes from v1: > - Change this driver as a clock driver from a generic phy driver. > https://patchwork.kernel.org/patch/9788697/ > - Remove "RFC" tag. > > .../bindings/clock/renesas,rcar-usb2-clock-sel.txt | 54 ++++++ > drivers/clk/renesas/Kconfig | 5 + > drivers/clk/renesas/Makefile | 1 + > drivers/clk/renesas/rcar-usb2-clock-sel.c | 205 +++++++++++++++++++++ > 4 files changed, 265 insertions(+) > create mode 100644 Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > create mode 100644 drivers/clk/renesas/rcar-usb2-clock-sel.c > > diff --git a/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > new file mode 100644 > index 0000000..75ccafc > --- /dev/null > +++ b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > @@ -0,0 +1,54 @@ > +* Renesas R-Car USB 2.0 clock selector > + > +This file provides information on what the device node for the R-Car USB 2.0 > +clock selector. > + > +If you connect an external clock to the USB_EXTAL pin only, you should set > +the clock rate to "usb_extal" node only. > +If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module > +is not needed because this is default setting. (Of course, you can set the > +clock rates to both "usb_extal" and "usb_xtal" nodes. > + > +Case 1: An external clock connects to R-Car SoC > + +----------+ +--- R-Car ---------------------+ > + |External |---|USB_EXTAL ---> all usb channels| > + |clock | |USB_XTAL | > + +----------+ +-------------------------------+ > +In this case, we need this driver with "usb_extal" clock. > + > +Case 2: An oscillator connects to R-Car SoC > + +----------+ +--- R-Car ---------------------+ > + |Oscillator|---|USB_EXTAL -+-> all usb channels| > + | |---|USB_XTAL --+ | > + +----------+ +-------------------------------+ > +In this case, we don't need this selector. > + > +Required properties: > +- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of > + an R8A7795 SoC. > + "renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of > + an R8A7796 SoC. > + "renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3 > + compatible device. > + > + When compatible with the generic version, nodes must list the > + SoC-specific version corresponding to the platform first > + followed by the generic version. > + > +- reg: offset and length of the USB 2.0 clock selector register block. > +- clocks: A list of phandles and specifier pairs. > +- clock-names: Name of the clocks. > + - The functional clock must be "ehci_ohci" > + - The USB_EXTAL clock pin must be "usb_extal" > + - The USB_XTAL clock pin must be "usb_xtal" > +- #clock-cells: Must be 0 > + > +Exxample (R-Car H3): > + > + usb2_clksel: clock-controller@e6590630 { > + compatible = "renesas,r8a77950-rcar-usb2-clock-sel", > + "renesas,rcar-gen3-usb2-clock-sel"; > + reg = <0 0xe6590630 0 0x02>; > + clocks = <&cpg CPG_MOD 703>, <&usb_extal>, <&usb_xtal>; > + clock-names = "ehci_ohci", "usb_extal", "usb_xtal"; Missing #clock-cells With that, for the binding: Acked-by: Rob Herring <robh@kernel.org> Rob -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 06/28, Yoshihiro Shimoda wrote: > + > + > + platform_set_drvdata(pdev, priv); > + dev_set_drvdata(dev, priv); > + > + init.name = "rcar_usb2_clock_sel"; > + init.ops = &usb2_clock_sel_clock_ops; > + init.flags = CLK_IS_BASIC; Please drop CLK_IS_BASIC unless you need it. > + init.parent_names = NULL; > + init.num_parents = 0; > + priv->hw.init = &init; > + > + clk = clk_register(NULL, &priv->hw); > + if (IS_ERR(clk)) > + return PTR_ERR(clk); > + > + error = of_clk_add_provider(np, of_clk_src_simple_get, clk); Can you use clk_hw_register() and of_clk_add_hw_provider() please? > + if (error) > + return error; > + > + return 0; > +} > + > +static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = { > + .suspend = rcar_usb2_clock_sel_suspend, > + .resume = rcar_usb2_clock_sel_resume, > +};
Hi Rob, > -----Original Message----- > From: Rob Herring > Sent: Wednesday, July 5, 2017 11:16 PM > > On Wed, Jun 28, 2017 at 03:28:35PM +0900, Yoshihiro Shimoda wrote: > > R-Car USB 2.0 controller can change the clock source from an oscillator > > to an external clock via a register. So, this patch adds support > > the clock source selector as a clock driver. > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > > --- > > This patch is based on the renesas-drivers.git / > > renesas-drivers-2017-06-27-v4.12-rc7 tag. > > > > Changes from v1: > > - Change this driver as a clock driver from a generic phy driver. > > https://patchwork.kernel.org/patch/9788697/ > > - Remove "RFC" tag. > > > > .../bindings/clock/renesas,rcar-usb2-clock-sel.txt | 54 ++++++ > > drivers/clk/renesas/Kconfig | 5 + > > drivers/clk/renesas/Makefile | 1 + > > drivers/clk/renesas/rcar-usb2-clock-sel.c | 205 +++++++++++++++++++++ > > 4 files changed, 265 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > > create mode 100644 drivers/clk/renesas/rcar-usb2-clock-sel.c > > > > diff --git a/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > > new file mode 100644 > > index 0000000..75ccafc > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt > > @@ -0,0 +1,54 @@ > > +* Renesas R-Car USB 2.0 clock selector > > + > > +This file provides information on what the device node for the R-Car USB 2.0 > > +clock selector. > > + > > +If you connect an external clock to the USB_EXTAL pin only, you should set > > +the clock rate to "usb_extal" node only. > > +If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module > > +is not needed because this is default setting. (Of course, you can set the > > +clock rates to both "usb_extal" and "usb_xtal" nodes. > > + > > +Case 1: An external clock connects to R-Car SoC > > + +----------+ +--- R-Car ---------------------+ > > + |External |---|USB_EXTAL ---> all usb channels| > > + |clock | |USB_XTAL | > > + +----------+ +-------------------------------+ > > +In this case, we need this driver with "usb_extal" clock. > > + > > +Case 2: An oscillator connects to R-Car SoC > > + +----------+ +--- R-Car ---------------------+ > > + |Oscillator|---|USB_EXTAL -+-> all usb channels| > > + | |---|USB_XTAL --+ | > > + +----------+ +-------------------------------+ > > +In this case, we don't need this selector. > > + > > +Required properties: > > +- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of > > + an R8A7795 SoC. > > + "renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of > > + an R8A7796 SoC. > > + "renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3 > > + compatible device. > > + > > + When compatible with the generic version, nodes must list the > > + SoC-specific version corresponding to the platform first > > + followed by the generic version. > > + > > +- reg: offset and length of the USB 2.0 clock selector register block. > > +- clocks: A list of phandles and specifier pairs. > > +- clock-names: Name of the clocks. > > + - The functional clock must be "ehci_ohci" > > + - The USB_EXTAL clock pin must be "usb_extal" > > + - The USB_XTAL clock pin must be "usb_xtal" > > +- #clock-cells: Must be 0 > > + > > +Exxample (R-Car H3): > > + > > + usb2_clksel: clock-controller@e6590630 { > > + compatible = "renesas,r8a77950-rcar-usb2-clock-sel", > > + "renesas,rcar-gen3-usb2-clock-sel"; > > + reg = <0 0xe6590630 0 0x02>; > > + clocks = <&cpg CPG_MOD 703>, <&usb_extal>, <&usb_xtal>; > > + clock-names = "ehci_ohci", "usb_extal", "usb_xtal"; > > Missing #clock-cells Oops, I will fix it. > With that, for the binding: > > Acked-by: Rob Herring <robh@kernel.org> Thank you for your Acked-by! Best regards, Yoshihiro Shimoda > Rob -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Stephen-san, Thank you for your comments! > From: Stephen Boyd > Sent: Thursday, July 6, 2017 6:18 AM > > On 06/28, Yoshihiro Shimoda wrote: > > + > > + > > + platform_set_drvdata(pdev, priv); > > + dev_set_drvdata(dev, priv); > > + > > + init.name = "rcar_usb2_clock_sel"; > > + init.ops = &usb2_clock_sel_clock_ops; > > + init.flags = CLK_IS_BASIC; > > Please drop CLK_IS_BASIC unless you need it. I got it. > > + init.parent_names = NULL; > > + init.num_parents = 0; > > + priv->hw.init = &init; > > + > > + clk = clk_register(NULL, &priv->hw); > > + if (IS_ERR(clk)) > > + return PTR_ERR(clk); > > + > > + error = of_clk_add_provider(np, of_clk_src_simple_get, clk); > > Can you use clk_hw_register() and of_clk_add_hw_provider() > please? I could use of_clk_add_hw_provider(). Best regards, Yoshihiro Shimoda > > + if (error) > > + return error; > > + > > + return 0; > > +} > > + > > +static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = { > > + .suspend = rcar_usb2_clock_sel_suspend, > > + .resume = rcar_usb2_clock_sel_resume, > > +}; > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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Hi Shimoda-san, On Mon, Jul 24, 2017 at 12:33 PM, Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> wrote: >> From: Geert Uytterhoeven >> Sent: Wednesday, July 5, 2017 9:22 PM >> On Wed, Jul 5, 2017 at 1:57 PM, Yoshihiro Shimoda >> <yoshihiro.shimoda.uh@renesas.com> wrote: >> >> From: Geert Uytterhoeven >> >> Sent: Wednesday, July 5, 2017 7:09 PM >> >> On Wed, Jun 28, 2017 at 8:28 AM, Yoshihiro Shimoda >> >> <yoshihiro.shimoda.uh@renesas.com> wrote: >> >> > R-Car USB 2.0 controller can change the clock source from an oscillator >> >> > to an external clock via a register. So, this patch adds support >> >> > the clock source selector as a clock driver. >> >> >> > --- /dev/null >> >> > +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c >> >> >> > +/* Since this driver needs other ccf drivers, this uses subsys_initcall_sync */ >> >> > +subsys_initcall_sync(rcar_usb2_clock_sel_init); >> >> >> >> I suppose this is a workaround for the lack of probe deferral support in the >> >> USB subsystem? >> > >> > This is my fault. I added "power-domains" property into this device's node. >> > After I remove the power-domains like the cpg node, this driver can use subsys_initcall() >> > instead of subsys_initcall_sync(). >> >> Does the clock sel module requires the functional clock "ehci_ohci" to be >> running before you can access its registers? >> If yes, I think there should be a "power-domains" property. > > Yes. But... > >> Then, you can simplify the code by calling >> >> pm_runtime_enable(dev); >> pm_runtime_get_sync(dev); >> >> and remove the explicit handling of the functional clock. >> >> That does not solve probe deferral handling in the USB subsystem, though. > > I added a debug message at end of cpg_mssr_probe(), and if I used subsys_initcall() on > rcar-usb2-clock-sel driver, kernel log output below: > ======================== > [ 0.272547] rcar-usb2-clock-sel e6590630.clock-controller: probe deferral not supported > [ 0.273944] ----------------- cpg_mssr_probe: probed! > ======================== > So, it seems the renesas-cpg-mssr.c doesn't solve probe deferral handling. > (The driver renesas-cpg-mssr.c uses platform_driver_probe() for now.) > > So, IIUC, this rcar-usb2-clock-sel driver cannot use subsys_initcall(). > Or, should we modify the renesas-cpg-mssr.c somehow? Drivers should avoid using subsys_initcall(). Why do you use a subsys_initcall()? To avoid probe deferral in the USB susbystem? What happens if the rcar-usb2-clock-sel uses builtin_platform_driver()? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Geert-san, > -----Original Message----- > From: Geert Uytterhoeven > Sent: Monday, July 24, 2017 9:59 PM > > Hi Shimoda-san, > > On Mon, Jul 24, 2017 at 12:33 PM, Yoshihiro Shimoda > <yoshihiro.shimoda.uh@renesas.com> wrote: > >> From: Geert Uytterhoeven > >> Sent: Wednesday, July 5, 2017 9:22 PM > >> On Wed, Jul 5, 2017 at 1:57 PM, Yoshihiro Shimoda > >> <yoshihiro.shimoda.uh@renesas.com> wrote: > >> >> From: Geert Uytterhoeven > >> >> Sent: Wednesday, July 5, 2017 7:09 PM > >> >> On Wed, Jun 28, 2017 at 8:28 AM, Yoshihiro Shimoda > >> >> <yoshihiro.shimoda.uh@renesas.com> wrote: > >> >> > R-Car USB 2.0 controller can change the clock source from an oscillator > >> >> > to an external clock via a register. So, this patch adds support > >> >> > the clock source selector as a clock driver. > >> > >> >> > --- /dev/null > >> >> > +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c > >> > >> >> > +/* Since this driver needs other ccf drivers, this uses subsys_initcall_sync */ > >> >> > +subsys_initcall_sync(rcar_usb2_clock_sel_init); > >> >> > >> >> I suppose this is a workaround for the lack of probe deferral support in the > >> >> USB subsystem? > >> > > >> > This is my fault. I added "power-domains" property into this device's node. > >> > After I remove the power-domains like the cpg node, this driver can use subsys_initcall() > >> > instead of subsys_initcall_sync(). > >> > >> Does the clock sel module requires the functional clock "ehci_ohci" to be > >> running before you can access its registers? > >> If yes, I think there should be a "power-domains" property. > > > > Yes. But... > > > >> Then, you can simplify the code by calling > >> > >> pm_runtime_enable(dev); > >> pm_runtime_get_sync(dev); > >> > >> and remove the explicit handling of the functional clock. > >> > >> That does not solve probe deferral handling in the USB subsystem, though. > > > > I added a debug message at end of cpg_mssr_probe(), and if I used subsys_initcall() on > > rcar-usb2-clock-sel driver, kernel log output below: > > ======================== > > [ 0.272547] rcar-usb2-clock-sel e6590630.clock-controller: probe deferral not supported > > [ 0.273944] ----------------- cpg_mssr_probe: probed! > > ======================== > > So, it seems the renesas-cpg-mssr.c doesn't solve probe deferral handling. > > (The driver renesas-cpg-mssr.c uses platform_driver_probe() for now.) > > > > So, IIUC, this rcar-usb2-clock-sel driver cannot use subsys_initcall(). > > Or, should we modify the renesas-cpg-mssr.c somehow? > > Drivers should avoid using subsys_initcall(). > Why do you use a subsys_initcall()? To avoid probe deferral in the USB > susbystem? Oh, this is my fault. I had assumed a clock driver should use subsys_initcall()... Like clk-fixed-rate.c, we can use builtin_platform_driver in general. > What happens if the rcar-usb2-clock-sel uses builtin_platform_driver()? I tried it today, and then the rcar-usb2-clock-sel works :) So, I will submit v3 patch. Best regards, Yoshihiro Shimoda > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
diff --git a/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt new file mode 100644 index 0000000..75ccafc --- /dev/null +++ b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt @@ -0,0 +1,54 @@ +* Renesas R-Car USB 2.0 clock selector + +This file provides information on what the device node for the R-Car USB 2.0 +clock selector. + +If you connect an external clock to the USB_EXTAL pin only, you should set +the clock rate to "usb_extal" node only. +If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module +is not needed because this is default setting. (Of course, you can set the +clock rates to both "usb_extal" and "usb_xtal" nodes. + +Case 1: An external clock connects to R-Car SoC + +----------+ +--- R-Car ---------------------+ + |External |---|USB_EXTAL ---> all usb channels| + |clock | |USB_XTAL | + +----------+ +-------------------------------+ +In this case, we need this driver with "usb_extal" clock. + +Case 2: An oscillator connects to R-Car SoC + +----------+ +--- R-Car ---------------------+ + |Oscillator|---|USB_EXTAL -+-> all usb channels| + | |---|USB_XTAL --+ | + +----------+ +-------------------------------+ +In this case, we don't need this selector. + +Required properties: +- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of + an R8A7795 SoC. + "renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of + an R8A7796 SoC. + "renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3 + compatible device. + + When compatible with the generic version, nodes must list the + SoC-specific version corresponding to the platform first + followed by the generic version. + +- reg: offset and length of the USB 2.0 clock selector register block. +- clocks: A list of phandles and specifier pairs. +- clock-names: Name of the clocks. + - The functional clock must be "ehci_ohci" + - The USB_EXTAL clock pin must be "usb_extal" + - The USB_XTAL clock pin must be "usb_xtal" +- #clock-cells: Must be 0 + +Exxample (R-Car H3): + + usb2_clksel: clock-controller@e6590630 { + compatible = "renesas,r8a77950-rcar-usb2-clock-sel", + "renesas,rcar-gen3-usb2-clock-sel"; + reg = <0 0xe6590630 0 0x02>; + clocks = <&cpg CPG_MOD 703>, <&usb_extal>, <&usb_xtal>; + clock-names = "ehci_ohci", "usb_extal", "usb_xtal"; + }; diff --git a/drivers/clk/renesas/Kconfig b/drivers/clk/renesas/Kconfig index 78d1df9..094df5c 100644 --- a/drivers/clk/renesas/Kconfig +++ b/drivers/clk/renesas/Kconfig @@ -114,6 +114,11 @@ config CLK_RCAR_GEN3_CPG bool select CLK_RENESAS_CPG_MSSR +config CLK_RCAR_USB2_CLOCK_SEL + bool "Renesas R-Car USB2 clock selector support" + depends on ARCH_RENESAS || COMPILE_TEST + help + This is a driver for R-Car USB2 clock selector # Generic config CLK_RENESAS_CPG_MSSR diff --git a/drivers/clk/renesas/Makefile b/drivers/clk/renesas/Makefile index 02d0412..4eec85b 100644 --- a/drivers/clk/renesas/Makefile +++ b/drivers/clk/renesas/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_CLK_SH73A0) += clk-sh73a0.o obj-$(CONFIG_CLK_RCAR_GEN2) += clk-rcar-gen2.o obj-$(CONFIG_CLK_RCAR_GEN2_CPG) += rcar-gen2-cpg.o obj-$(CONFIG_CLK_RCAR_GEN3_CPG) += rcar-gen3-cpg.o +obj-$(CONFIG_CLK_RCAR_USB2_CLOCK_SEL) += rcar-usb2-clock-sel.o # Generic obj-$(CONFIG_CLK_RENESAS_CPG_MSSR) += renesas-cpg-mssr.o diff --git a/drivers/clk/renesas/rcar-usb2-clock-sel.c b/drivers/clk/renesas/rcar-usb2-clock-sel.c new file mode 100644 index 0000000..b48b2fc --- /dev/null +++ b/drivers/clk/renesas/rcar-usb2-clock-sel.c @@ -0,0 +1,205 @@ +/* + * Renesas R-Car USB2.0 clock selector + * + * Copyright (C) 2017 Renesas Electronics Corp. + * + * Based on renesas-cpg-mssr.c + * + * Copyright (C) 2015 Glider bvba + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/slab.h> + +#define USB20_CLKSET0 0x00 +#define CLKSET0_INTCLK_EN BIT(11) +#define CLKSET0_PRIVATE BIT(0) +#define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE) + +struct usb2_clock_sel_priv { + void __iomem *base; + struct clk_hw hw; + struct clk *ehci_clk; + bool extal; + bool xtal; +}; +#define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw) + +static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv) +{ + u16 val = readw(priv->base + USB20_CLKSET0); + + pr_debug("%s: enter %d %d %x\n", __func__, + priv->extal, priv->xtal, val); + + if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY) + writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0); +} + +static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv) +{ + if (priv->extal && !priv->xtal) + writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0); +} + +static int usb2_clock_sel_enable(struct clk_hw *hw) +{ + usb2_clock_sel_enable_extal_only(to_priv(hw)); + + return 0; +} + +static void usb2_clock_sel_disable(struct clk_hw *hw) +{ + usb2_clock_sel_disable_extal_only(to_priv(hw)); +} + +/* + * This module seems a mux, but this driver assumes a gate because + * ehci/ohci platform drivers don't support clk_set_parent() for now. + * If this driver acts as a gate, ehci/ohci-platform drivers don't need + * any modification. + */ +static const struct clk_ops usb2_clock_sel_clock_ops = { + .enable = usb2_clock_sel_enable, + .disable = usb2_clock_sel_disable, +}; + +static const struct of_device_id rcar_usb2_clock_sel_match[] = { + { .compatible = "renesas,rcar-gen3-usb2-clock-sel" }, + { } +}; + +static int rcar_usb2_clock_sel_suspend(struct device *dev) +{ + struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); + + usb2_clock_sel_disable_extal_only(priv); + clk_disable_unprepare(priv->ehci_clk); + + return 0; +} + +static int rcar_usb2_clock_sel_resume(struct device *dev) +{ + struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); + int error; + + error = clk_prepare_enable(priv->ehci_clk); + if (error) + return error; + usb2_clock_sel_enable_extal_only(priv); + + return 0; +} + +static int rcar_usb2_clock_sel_remove(struct platform_device *pdev) +{ + struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev); + + clk_disable_unprepare(priv->ehci_clk); + of_clk_del_provider(pdev->dev.of_node); + clk_hw_unregister(&priv->hw); + + return 0; +} + +static int __init rcar_usb2_clock_sel_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct usb2_clock_sel_priv *priv; + struct resource *res; + struct clk *clk; + struct clk_init_data init; + int error; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->base = devm_ioremap_resource(dev, res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->ehci_clk = devm_clk_get(dev, "ehci_ohci"); + if (!IS_ERR(priv->ehci_clk)) { + error = clk_prepare_enable(priv->ehci_clk); + if (error) + return error; + } + + clk = devm_clk_get(dev, "usb_extal"); + if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { + priv->extal = !!clk_get_rate(clk); + clk_disable_unprepare(clk); + } + clk = devm_clk_get(dev, "usb_xtal"); + if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { + priv->xtal = !!clk_get_rate(clk); + clk_disable_unprepare(clk); + } + + if (!priv->extal && !priv->extal) { + dev_err(dev, "This driver needs usb_extal or usb_xtal\n"); + return -ENOENT; + } + + platform_set_drvdata(pdev, priv); + dev_set_drvdata(dev, priv); + + init.name = "rcar_usb2_clock_sel"; + init.ops = &usb2_clock_sel_clock_ops; + init.flags = CLK_IS_BASIC; + init.parent_names = NULL; + init.num_parents = 0; + priv->hw.init = &init; + + clk = clk_register(NULL, &priv->hw); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + error = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (error) + return error; + + return 0; +} + +static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = { + .suspend = rcar_usb2_clock_sel_suspend, + .resume = rcar_usb2_clock_sel_resume, +}; + +static struct platform_driver rcar_usb2_clock_sel_driver = { + .driver = { + .name = "rcar-usb2-clock-sel", + .pm = &rcar_usb2_clock_sel_pm_ops, + .of_match_table = rcar_usb2_clock_sel_match, + }, + .remove = rcar_usb2_clock_sel_remove, +}; + +static int __init rcar_usb2_clock_sel_init(void) +{ + return platform_driver_probe(&rcar_usb2_clock_sel_driver, + rcar_usb2_clock_sel_probe); +} + +/* Since this driver needs other ccf drivers, this uses subsys_initcall_sync */ +subsys_initcall_sync(rcar_usb2_clock_sel_init); + +MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver"); +MODULE_LICENSE("GPL v2");
R-Car USB 2.0 controller can change the clock source from an oscillator to an external clock via a register. So, this patch adds support the clock source selector as a clock driver. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> --- This patch is based on the renesas-drivers.git / renesas-drivers-2017-06-27-v4.12-rc7 tag. Changes from v1: - Change this driver as a clock driver from a generic phy driver. https://patchwork.kernel.org/patch/9788697/ - Remove "RFC" tag. .../bindings/clock/renesas,rcar-usb2-clock-sel.txt | 54 ++++++ drivers/clk/renesas/Kconfig | 5 + drivers/clk/renesas/Makefile | 1 + drivers/clk/renesas/rcar-usb2-clock-sel.c | 205 +++++++++++++++++++++ 4 files changed, 265 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt create mode 100644 drivers/clk/renesas/rcar-usb2-clock-sel.c