Hi Rob, > -----Original Message----- > From: Rob Herring [mailto:robh@xxxxxxxxxx] > Sent: 2016年6月9日 4:27 > To: Yang, Wenyou <Wenyou.Yang@xxxxxxxxx> > Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>; Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx>; Ferre, Nicolas <Nicolas.FERRE@xxxxxxxxx>; > Pawel Moll <pawel.moll@xxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>; Ian > Campbell <ijc+devicetree@xxxxxxxxxxxxxx>; Kumar Gala <galak@xxxxxxxxxxxxxx>; > Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>; linux- > kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v3 1/2] usb: ohci-at91: Forcibly suspend ports while USB > suspend > > On Wed, Jun 08, 2016 at 12:15:10PM +0800, Wenyou Yang wrote: > > In order to the save power consumption, as a workaround, suspend > > forcibly the USB PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI > > Interrupt Configuration Register in the SFRs while OHCI USB suspend. > > > > This suspend operation must be done before the USB clock is disabled, > > resume after the USB clock is enabled. > > > > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx> > > --- > > > > Changes in v3: > > - Change the compatible description for more precise. > > > > Changes in v2: > > - Add compatible to support forcibly suspend the ports. > > - Add soc/at91/at91_sfr.h to accommodate the defines. > > - Add error checking for .sfr_regmap. > > - Remove unnecessary regmap_read() statement. > > > > .../devicetree/bindings/usb/atmel-usb.txt | 6 +- > > drivers/usb/host/ohci-at91.c | 80 +++++++++++++++++++++- > > include/soc/at91/at91_sfr.h | 29 ++++++++ > > 3 files changed, 112 insertions(+), 3 deletions(-) create mode > > 100644 include/soc/at91/at91_sfr.h > > > > diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt > > b/Documentation/devicetree/bindings/usb/atmel-usb.txt > > index 5883b73..888deaa 100644 > > --- a/Documentation/devicetree/bindings/usb/atmel-usb.txt > > +++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt > > @@ -3,8 +3,10 @@ Atmel SOC USB controllers OHCI > > > > Required properties: > > - - compatible: Should be "atmel,at91rm9200-ohci" for USB controllers > > - used in host mode. > > + - compatible: Should be one of the following > > + "atmel,at91rm9200-ohci" for USB controllers used in host mode. > > + "atmel,sama5d2-ohci" for USB controllers used in host mode > > + on SAMA5D2 which can force to suspend. > > Guess I wasn't clear enough before. Drop "which can force to suspend". In previous mail, Nicolas gave a suggestion with "...on SAMA5D2 and compatible SoCs that must explicitly force suspend through the Special Function Register (SFR)." I think it is more clear, what is your opinion? > > > - reg: Address and length of the register set for the device > > - interrupts: Should contain ehci interrupt > > - clocks: Should reference the peripheral, host and system clocks > > diff --git a/drivers/usb/host/ohci-at91.c > > b/drivers/usb/host/ohci-at91.c index d177372..54e8feb 100644 > > --- a/drivers/usb/host/ohci-at91.c > > +++ b/drivers/usb/host/ohci-at91.c > > @@ -21,8 +21,11 @@ > > #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> > > +#include <soc/at91/at91_sfr.h> > > > > #include "ohci.h" > > > > @@ -45,12 +48,18 @@ struct at91_usbh_data { > > u8 overcurrent_changed[AT91_MAX_USBH_PORTS]; > > }; > > > > +struct ohci_at91_caps { > > + bool suspend_ctrl; > > +}; > > + > > struct ohci_at91_priv { > > struct clk *iclk; > > struct clk *fclk; > > struct clk *hclk; > > bool clocked; > > bool wakeup; /* Saved wake-up state for resume */ > > + const struct ohci_at91_caps *caps; > > + struct regmap *sfr_regmap; > > }; > > /* interface and function clocks; sometimes also an AHB clock */ > > > > @@ -132,6 +141,17 @@ 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)) > > + regmap = 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 > > +217,17 @@ static int usb_hcd_at91_probe(const struct hc_driver *driver, > > goto err; > > } > > > > + ohci_at91->caps = (const struct ohci_at91_caps *) > > + of_device_get_match_data(&pdev->dev); > > + if (!ohci_at91->caps) > > + return -ENODEV; > > + > > + if (ohci_at91->caps->suspend_ctrl) { > > + ohci_at91->sfr_regmap = at91_dt_syscon_sfr(); > > + if (!ohci_at91->sfr_regmap) > > + dev_warn(dev, "failed to find sfr node\n"); > > + } > > + > > board = hcd->self.controller->platform_data; > > ohci = hcd_to_ohci(hcd); > > ohci->num_ports = board->ports; > > @@ -440,8 +471,17 @@ static irqreturn_t ohci_hcd_at91_overcurrent_irq(int > irq, void *data) > > return IRQ_HANDLED; > > } > > > > +static const struct ohci_at91_caps at91rm9200_caps = { > > + .suspend_ctrl = false, > > +}; > > + > > +static const struct ohci_at91_caps sama5d2_caps = { > > + .suspend_ctrl = true, > > +}; > > + > > static const struct of_device_id at91_ohci_dt_ids[] = { > > - { .compatible = "atmel,at91rm9200-ohci" }, > > + { .compatible = "atmel,at91rm9200-ohci", .data = &at91rm9200_caps }, > > + { .compatible = "atmel,sama5d2-ohci", .data = &sama5d2_caps }, > > { /* sentinel */ } > > }; > > > > @@ -581,6 +621,38 @@ static int ohci_hcd_at91_drv_remove(struct > platform_device *pdev) > > return 0; > > } > > > > +static int ohci_at91_port_ctrl(struct regmap *regmap, bool enable) { > > + u32 regval; > > + int ret; > > + > > + if (!regmap) > > + return -EINVAL; > > + > > + 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); > > + > > + 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 +690,9 @@ > > ohci_hcd_at91_drv_suspend(struct device *dev) > > ohci_writel(ohci, ohci->hc_control, &ohci->regs->control); > > ohci->rh_state = OHCI_RH_HALTED; > > > > + if (ohci_at91->caps->suspend_ctrl) > > + 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 +712,9 @@ ohci_hcd_at91_drv_resume(struct device *dev) > > > > at91_start_clock(ohci_at91); > > > > + if (ohci_at91->caps->suspend_ctrl) > > + ohci_at91_port_resume(ohci_at91->sfr_regmap); > > + > > ohci_resume(hcd, false); > > return 0; > > } > > diff --git a/include/soc/at91/at91_sfr.h b/include/soc/at91/at91_sfr.h > > new file mode 100644 index 0000000..04a3a1e > > --- /dev/null > > +++ b/include/soc/at91/at91_sfr.h > > @@ -0,0 +1,29 @@ > > +/* > > + * Header file for the Atmel DDR/SDR SDRAM Controller > > + * > > + * Copyright (C) 2016 Atmel Corporation > > + * > > + * Author: Wenyou Yang <wenyou.yang@xxxxxxxxx> > > + * > > + * This program is free software; you can redistribute it and/or > > +modify > > + * it under the terms of the GNU General Public License version 2 as > > + * published by the Free Software Foundation. > > + * > > + */ > > +#ifndef __AT91_SFR_H__ > > +#define __AT91_SFR_H__ > > + > > +#define SFR_DDRCFG 0x04 /* DDR Configuration Register */ > > +/* 0x08 ~ 0x0c: Reserved */ > > +#define SFR_OHCIICR 0x10 /* OHCI Interrupt Configuration > Register */ > > +#define SFR_OHCIISR 0x14 /* OHCI Interrupt Status Register > */ > > + > > +#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) > > + > > +#endif > > -- > > 2.7.4 > > Best Regards, Wenyou Yang ?韬{.n?????%??檩??w?{.n????z谵{???塄}?财??j:+v?? ? ???2??璀??摺?囤??z夸z罐?+?????w棹f
