| Message ID | 1463015134-32364-1-git-send-email-wenyou.yang@atmel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 12/05/2016 at 09:05:34 +0800, Wenyou Yang wrote : > In order to get lower consumption, as a workaround, suspend > the USB PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI Interrupt > Configuration Register while OHCI USB suspending. > Why is that a workaround? > This suspend operation must be done before stopping the USB clock, > resume after the USB clock enabled. > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > --- > > drivers/usb/host/ohci-at91.c | 63 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c > index d177372..ce898e0 100644 > --- a/drivers/usb/host/ohci-at91.c > +++ b/drivers/usb/host/ohci-at91.c > @@ -21,6 +21,8 @@ > #include <linux/io.h> > #include <linux/kernel.h> > #include <linux/module.h> > +#include <linux/mfd/syscon.h> > +#include <linux/regmap.h> > #include <linux/usb.h> > #include <linux/usb/hcd.h> > > @@ -51,6 +53,7 @@ struct ohci_at91_priv { > struct clk *hclk; > bool clocked; > bool wakeup; /* Saved wake-up state for resume */ > + struct regmap *sfr_regmap; > }; > /* interface and function clocks; sometimes also an AHB clock */ > > @@ -132,6 +135,17 @@ static void at91_stop_hc(struct platform_device *pdev) > > /*-------------------------------------------------------------------------*/ > > +struct regmap *at91_dt_syscon_sfr(void) > +{ > + struct regmap *regmap; > + > + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); > + if (IS_ERR(regmap)) > + return NULL; > + > + return regmap; > +} > + > static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *); > > /* configure so an HC device and id are always provided */ > @@ -197,6 +211,8 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, > goto err; > } > > + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); > + > board = hcd->self.controller->platform_data; > ohci = hcd_to_ohci(hcd); > ohci->num_ports = board->ports; > @@ -581,6 +597,49 @@ static int ohci_hcd_at91_drv_remove(struct platform_device *pdev) > return 0; > } > > +#define SFR_OHCIICR 0x10 > +#define SFR_OHCIICR_SUSPEND_A BIT(8) > +#define SFR_OHCIICR_SUSPEND_B BIT(9) > +#define SFR_OHCIICR_SUSPEND_C BIT(10) > + > +#define SFR_OHCIICR_USB_SUSPEND (SFR_OHCIICR_SUSPEND_A | \ > + SFR_OHCIICR_SUSPEND_B | \ > + SFR_OHCIICR_SUSPEND_C) > + Those defines should go in a header file either in include/soc/at91 or in include/linux/mfd > +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) > +{ > + u32 regval; > + int ret; > + > + if (IS_ERR(regmap)) > + return PTR_ERR(regmap); > + > + ret = regmap_read(regmap, SFR_OHCIICR, ®val); > + if (ret) > + return ret; > + > + if (enable) > + regval &= ~SFR_OHCIICR_USB_SUSPEND; > + else > + regval |= SFR_OHCIICR_USB_SUSPEND; > + > + regmap_write(regmap, SFR_OHCIICR, regval); > + > + regmap_read(regmap, SFR_OHCIICR, ®val); > + > + return 0; > +} > + > +static int ohci_at91_port_suspend(struct regmap *regmap) > +{ > + return ohci_at91_port_ctrl(regmap, false); > +} > + > +static int ohci_at91_port_resume(struct regmap *regmap) > +{ > + return ohci_at91_port_ctrl(regmap, true); > +} > + > static int __maybe_unused > ohci_hcd_at91_drv_suspend(struct device *dev) > { > @@ -618,6 +677,8 @@ ohci_hcd_at91_drv_suspend(struct device *dev) > ohci_writel(ohci, ohci->hc_control, &ohci->regs->control); > ohci->rh_state = OHCI_RH_HALTED; > > + ohci_at91_port_suspend(ohci_at91->sfr_regmap); > + The main issue I see here is that you will call that function for all SoCs and it will always fail unless it is running on a sama5d2. Maybe we could be smarter about that.
> -----Original Message----- > From: Alexandre Belloni [mailto:alexandre.belloni@free-electrons.com] > Sent: 2016?5?12? 11:53 > To: Yang, Wenyou <Wenyou.Yang@atmel.com> > Cc: Alan Stern <stern@rowland.harvard.edu>; Greg Kroah-Hartman > <gregkh@linuxfoundation.org>; Ferre, Nicolas <Nicolas.FERRE@atmel.com>; > linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- > kernel@lists.infradead.org > Subject: Re: [PATCH] usb: ohci-at91: Suspend the ports while USB suspending > > Hi, > > On 12/05/2016 at 09:05:34 +0800, Wenyou Yang wrote : > > In order to get lower consumption, as a workaround, suspend the USB > > PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI Interrupt > > Configuration Register while OHCI USB suspending. > > > > Why is that a workaround? Because if these bits is not set as this patch, there is 5mA current left at VDDOSC rail during suspend. If apply this patch, this current will disappear. So, I think it is a workaround. > > > This suspend operation must be done before stopping the USB clock, > > resume after the USB clock enabled. > > > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > > --- > > > > drivers/usb/host/ohci-at91.c | 63 > > ++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 63 insertions(+) > > > > diff --git a/drivers/usb/host/ohci-at91.c > > b/drivers/usb/host/ohci-at91.c index d177372..ce898e0 100644 > > --- a/drivers/usb/host/ohci-at91.c > > +++ b/drivers/usb/host/ohci-at91.c > > @@ -21,6 +21,8 @@ > > #include <linux/io.h> > > #include <linux/kernel.h> > > #include <linux/module.h> > > +#include <linux/mfd/syscon.h> > > +#include <linux/regmap.h> > > #include <linux/usb.h> > > #include <linux/usb/hcd.h> > > > > @@ -51,6 +53,7 @@ struct ohci_at91_priv { > > struct clk *hclk; > > bool clocked; > > bool wakeup; /* Saved wake-up state for resume */ > > + struct regmap *sfr_regmap; > > }; > > /* interface and function clocks; sometimes also an AHB clock */ > > > > @@ -132,6 +135,17 @@ static void at91_stop_hc(struct platform_device > > *pdev) > > > > > > /*-------------------------------------------------------------------- > > -----*/ > > > > +struct regmap *at91_dt_syscon_sfr(void) { > > + struct regmap *regmap; > > + > > + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); > > + if (IS_ERR(regmap)) > > + return NULL; > > + > > + return regmap; > > +} > > + > > static void usb_hcd_at91_remove (struct usb_hcd *, struct > > platform_device *); > > > > /* configure so an HC device and id are always provided */ @@ -197,6 > > +211,8 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, > > goto err; > > } > > > > + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); > > + > > board = hcd->self.controller->platform_data; > > ohci = hcd_to_ohci(hcd); > > ohci->num_ports = board->ports; > > @@ -581,6 +597,49 @@ static int ohci_hcd_at91_drv_remove(struct > platform_device *pdev) > > return 0; > > } > > > > +#define SFR_OHCIICR 0x10 > > +#define SFR_OHCIICR_SUSPEND_A BIT(8) > > +#define SFR_OHCIICR_SUSPEND_B BIT(9) > > +#define SFR_OHCIICR_SUSPEND_C BIT(10) > > + > > +#define SFR_OHCIICR_USB_SUSPEND (SFR_OHCIICR_SUSPEND_A | \ > > + SFR_OHCIICR_SUSPEND_B | \ > > + SFR_OHCIICR_SUSPEND_C) > > + > > Those defines should go in a header file either in include/soc/at91 or in > include/linux/mfd > > > +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) { > > + u32 regval; > > + int ret; > > + > > + if (IS_ERR(regmap)) > > + return PTR_ERR(regmap); > > + > > + ret = regmap_read(regmap, SFR_OHCIICR, ®val); > > + if (ret) > > + return ret; > > + > > + if (enable) > > + regval &= ~SFR_OHCIICR_USB_SUSPEND; > > + else > > + regval |= SFR_OHCIICR_USB_SUSPEND; > > + > > + regmap_write(regmap, SFR_OHCIICR, regval); > > + > > + regmap_read(regmap, SFR_OHCIICR, ®val); > > + > > + return 0; > > +} > > + > > +static int ohci_at91_port_suspend(struct regmap *regmap) { > > + return ohci_at91_port_ctrl(regmap, false); } > > + > > +static int ohci_at91_port_resume(struct regmap *regmap) { > > + return ohci_at91_port_ctrl(regmap, true); } > > + > > static int __maybe_unused > > ohci_hcd_at91_drv_suspend(struct device *dev) { @@ -618,6 +677,8 @@ > > ohci_hcd_at91_drv_suspend(struct device *dev) > > ohci_writel(ohci, ohci->hc_control, &ohci->regs->control); > > ohci->rh_state = OHCI_RH_HALTED; > > > > + ohci_at91_port_suspend(ohci_at91->sfr_regmap); > > + > > The main issue I see here is that you will call that function for all SoCs and it will > always fail unless it is running on a sama5d2. Maybe we could be smarter about > that. Can we use another compatible, such as "atmel,sama5d2-ohci" to differentiate it? Best Regards, Wenyou Yang
On Thu, 12 May 2016, Wenyou Yang wrote: > In order to get lower consumption, as a workaround, suspend > the USB PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI Interrupt > Configuration Register while OHCI USB suspending. What does this mean? What does suspending a port do? Is it the same as a normal USB port suspend? If it is the same, why doesn't the USB_PORT_FEAT_SUSPEND subcase of the SetPortFeature case in ohci_hub_control() already take care of this? > This suspend operation must be done before stopping the USB clock, > resume after the USB clock enabled. > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > --- > @@ -132,6 +135,17 @@ static void at91_stop_hc(struct platform_device *pdev) > > /*-------------------------------------------------------------------------*/ > > +struct regmap *at91_dt_syscon_sfr(void) > +{ > + struct regmap *regmap; > + > + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); > + if (IS_ERR(regmap)) > + return NULL; If you get an error, the regmap pointer is set to NULL... > @@ -197,6 +211,8 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, > goto err; > } > > + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); With no other error checking... > + > board = hcd->self.controller->platform_data; > ohci = hcd_to_ohci(hcd); > ohci->num_ports = board->ports; > +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) > +{ > + u32 regval; > + int ret; > + > + if (IS_ERR(regmap)) > + return PTR_ERR(regmap); > + > + ret = regmap_read(regmap, SFR_OHCIICR, ®val); And now what happens if regmap is NULL? Hint: It won't be pretty... Alan Stern
Hi Alan, > -----Original Message----- > From: Alan Stern [mailto:stern@rowland.harvard.edu] > Sent: 2016?5?13? 2:11 > To: Yang, Wenyou <Wenyou.Yang@atmel.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Ferre, Nicolas > <Nicolas.FERRE@atmel.com>; linux-usb@vger.kernel.org; linux- > kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org > Subject: Re: [PATCH] usb: ohci-at91: Suspend the ports while USB suspending > > On Thu, 12 May 2016, Wenyou Yang wrote: > > > In order to get lower consumption, as a workaround, suspend the USB > > PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI Interrupt > > Configuration Register while OHCI USB suspending. > > What does this mean? What does suspending a port do? It is a IP workaround for SAMA5D2 USB. By setting corresponding bits of a specific register to get lower consumption. > Is it the same as a normal USB port suspend? No, it is not same. > > If it is the same, why doesn't the USB_PORT_FEAT_SUSPEND subcase of the > SetPortFeature case in ohci_hub_control() already take care of this? > > > This suspend operation must be done before stopping the USB clock, > > resume after the USB clock enabled. > > > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > > --- > > > @@ -132,6 +135,17 @@ static void at91_stop_hc(struct platform_device > > *pdev) > > > > > > /*-------------------------------------------------------------------- > > -----*/ > > > > +struct regmap *at91_dt_syscon_sfr(void) { > > + struct regmap *regmap; > > + > > + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); > > + if (IS_ERR(regmap)) > > + return NULL; > > If you get an error, the regmap pointer is set to NULL... > > > @@ -197,6 +211,8 @@ static int usb_hcd_at91_probe(const struct hc_driver > *driver, > > goto err; > > } > > > > + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); > > With no other error checking... Add error checking in next version. > > > + > > board = hcd->self.controller->platform_data; > > ohci = hcd_to_ohci(hcd); > > ohci->num_ports = board->ports; > > > +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) { > > + u32 regval; > > + int ret; > > + > > + if (IS_ERR(regmap)) > > + return PTR_ERR(regmap); > > + > > + ret = regmap_read(regmap, SFR_OHCIICR, ®val); > > And now what happens if regmap is NULL? Hint: It won't be pretty... Yes, it is not pretty. Will rework in next version. > > Alan Stern Best Regards, Wenyou Yang
Hi Alan, Sorry for late answer. > -----Original Message----- > From: Alan Stern [mailto:stern@rowland.harvard.edu] > Sent: 2016年5月13日 2:11 > To: Yang, Wenyou <Wenyou.Yang@atmel.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Ferre, Nicolas > <Nicolas.FERRE@atmel.com>; linux-usb@vger.kernel.org; linux- > kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org > Subject: Re: [PATCH] usb: ohci-at91: Suspend the ports while USB suspending > > On Thu, 12 May 2016, Wenyou Yang wrote: > > > In order to get lower consumption, as a workaround, suspend the USB > > PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI Interrupt > > Configuration Register while OHCI USB suspending. > > What does this mean? What does suspending a port do? Is it the same as a > normal USB port suspend? The usb controller from Synopsis does not managed correctly the suspend mode for the EHCI. There is no way to have the VDDUTMII (USB device and host UTMI interface) suspend without any device connected to it. That's why we added this specific control to fix this issue. Namely, by setting some bits of one of the special function registers to fix this issue outside the usb controller. And the suspend mode works in OHCI mode. It is not same as a normal USB port suspend. > > If it is the same, why doesn't the USB_PORT_FEAT_SUSPEND subcase of the > SetPortFeature case in ohci_hub_control() already take care of this? > > > This suspend operation must be done before stopping the USB clock, > > resume after the USB clock enabled. > > > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > > --- > > > @@ -132,6 +135,17 @@ static void at91_stop_hc(struct platform_device > > *pdev) > > > > > > /*-------------------------------------------------------------------- > > -----*/ > > > > +struct regmap *at91_dt_syscon_sfr(void) { > > + struct regmap *regmap; > > + > > + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); > > + if (IS_ERR(regmap)) > > + return NULL; > > If you get an error, the regmap pointer is set to NULL... > > > @@ -197,6 +211,8 @@ static int usb_hcd_at91_probe(const struct hc_driver > *driver, > > goto err; > > } > > > > + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); > > With no other error checking... > > > + > > board = hcd->self.controller->platform_data; > > ohci = hcd_to_ohci(hcd); > > ohci->num_ports = board->ports; > > > +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) { > > + u32 regval; > > + int ret; > > + > > + if (IS_ERR(regmap)) > > + return PTR_ERR(regmap); > > + > > + ret = regmap_read(regmap, SFR_OHCIICR, ®val); > > And now what happens if regmap is NULL? Hint: It won't be pretty... > > Alan Stern Best Regards, Wenyou Yang
Hi Alan,
diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c index d177372..ce898e0 100644 --- a/drivers/usb/host/ohci-at91.c +++ b/drivers/usb/host/ohci-at91.c @@ -21,6 +21,8 @@ #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> #include <linux/usb.h> #include <linux/usb/hcd.h> @@ -51,6 +53,7 @@ struct ohci_at91_priv { struct clk *hclk; bool clocked; bool wakeup; /* Saved wake-up state for resume */ + struct regmap *sfr_regmap; }; /* interface and function clocks; sometimes also an AHB clock */ @@ -132,6 +135,17 @@ static void at91_stop_hc(struct platform_device *pdev) /*-------------------------------------------------------------------------*/ +struct regmap *at91_dt_syscon_sfr(void) +{ + struct regmap *regmap; + + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); + if (IS_ERR(regmap)) + return NULL; + + return regmap; +} + static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *); /* configure so an HC device and id are always provided */ @@ -197,6 +211,8 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, goto err; } + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); + board = hcd->self.controller->platform_data; ohci = hcd_to_ohci(hcd); ohci->num_ports = board->ports; @@ -581,6 +597,49 @@ static int ohci_hcd_at91_drv_remove(struct platform_device *pdev) return 0; } +#define SFR_OHCIICR 0x10 +#define SFR_OHCIICR_SUSPEND_A BIT(8) +#define SFR_OHCIICR_SUSPEND_B BIT(9) +#define SFR_OHCIICR_SUSPEND_C BIT(10) + +#define SFR_OHCIICR_USB_SUSPEND (SFR_OHCIICR_SUSPEND_A | \ + SFR_OHCIICR_SUSPEND_B | \ + SFR_OHCIICR_SUSPEND_C) + +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) +{ + u32 regval; + int ret; + + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + ret = regmap_read(regmap, SFR_OHCIICR, ®val); + if (ret) + return ret; + + if (enable) + regval &= ~SFR_OHCIICR_USB_SUSPEND; + else + regval |= SFR_OHCIICR_USB_SUSPEND; + + regmap_write(regmap, SFR_OHCIICR, regval); + + regmap_read(regmap, SFR_OHCIICR, ®val); + + return 0; +} + +static int ohci_at91_port_suspend(struct regmap *regmap) +{ + return ohci_at91_port_ctrl(regmap, false); +} + +static int ohci_at91_port_resume(struct regmap *regmap) +{ + return ohci_at91_port_ctrl(regmap, true); +} + static int __maybe_unused ohci_hcd_at91_drv_suspend(struct device *dev) { @@ -618,6 +677,8 @@ ohci_hcd_at91_drv_suspend(struct device *dev) ohci_writel(ohci, ohci->hc_control, &ohci->regs->control); ohci->rh_state = OHCI_RH_HALTED; + ohci_at91_port_suspend(ohci_at91->sfr_regmap); + /* flush the writes */ (void) ohci_readl (ohci, &ohci->regs->control); at91_stop_clock(ohci_at91); @@ -637,6 +698,8 @@ ohci_hcd_at91_drv_resume(struct device *dev) at91_start_clock(ohci_at91); + ohci_at91_port_resume(ohci_at91->sfr_regmap); + ohci_resume(hcd, false); return 0; }
In order to get lower consumption, as a workaround, suspend the USB PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI Interrupt Configuration Register while OHCI USB suspending. This suspend operation must be done before stopping the USB clock, resume after the USB clock enabled. Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> --- drivers/usb/host/ohci-at91.c | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+)