Hi, > -----Original Message----- > From: ext Jarkko Nikula [mailto:jhnikula@xxxxxxxxx] > Sent: 21. maaliskuuta 2011 17:21 > To: Jokiniemi Kalle (Nokia-MS/Tampere) > Cc: linux-usb@xxxxxxxxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx; balbi@xxxxxx; > tony@xxxxxxxxxxx; Krogerus Heikki (Nokia-MS/Helsinki); Koskinen Ilkka > (Nokia-MS/Tampere) > Subject: Re: [PATCH 2/2] OMAP3: rx51: specify phy_power for usb tranceiver > > On Mon, 21 Mar 2011 15:50:20 +0200 > Kalle Jokiniemi <kalle.jokiniemi@xxxxxxxxx> wrote: > > > This patch allows the ISP1707 USB tranceiver on Nokia > > N900 to be disabled when usb cable is disconnected. > > This saves approximately 14mA of battery current. > > > I can measure that these two patches save about 14 mA. > > > +static void __init rx51_xceiv_init(void) > > +{ > > + if (gpio_request(RX51_USB_TRANSCEIVER_RST_GPIO, NULL) < 0) > > + BUG(); > > + gpio_direction_output(RX51_USB_TRANSCEIVER_RST_GPIO, 1); > > +} > > gpio_request_one makes this function needless. Thanks for the pointer, I'll look that up. Though, I want to still keep a function for the init for readability to clearly point out what is being initialized. > > > +static int rx51_xceiv_power(struct device *dev, int iD, int on) > > +{ > > + unsigned long timeout; > > + > > + if (!on) { > > + /* Let musb go stdby before powering down the transceiver */ > > + timeout = jiffies + msecs_to_jiffies(100); > > + while (!time_after(jiffies, timeout)) > > + if (omap2_cm_read_mod_reg(CORE_MOD, > CM_IDLEST1) > > + & > OMAP3430ES2_ST_HSOTGUSB_STDBY_MASK) > > + break; > > + if (!(omap2_cm_read_mod_reg(CORE_MOD, CM_IDLEST1) > > + & OMAP3430ES2_ST_HSOTGUSB_STDBY_MASK)) > > + WARN(1, "could not put musb to sleep\n"); > > + } > > + gpio_set_value(RX51_USB_TRANSCEIVER_RST_GPIO, on); > > + > > Hmm... 100 ms busy loop. I wonder are there better ways in usb to > achieve this gpio control than this loop here and playing with these > registers? I believe musb/phy/etc has knowledge when they are idle and > can do some board specific stuff? Will clean this up. Have to look at that isp1704_charger to see if it can be responsible of the correct state checks... - Kalle > > -- > Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
