On Thursday, September 11, 2014 4:32:20 PM UTC-4, RobertCNelson wrote: > > On Thu, Sep 11, 2014 at 1:57 PM, Jason Kridner <[email protected]> > wrote: > > > > > > On Thursday, September 11, 2014 10:39:25 AM UTC-4, RobertCNelson wrote: > >> > >> On Thu, Sep 11, 2014 at 9:23 AM, Tom Rini <[email protected]> wrote: > >> > On Friday, September 5, 2014 1:39:04 PM UTC-4, RobertCNelson wrote: > >> >> > >> >> On Fri, Sep 5, 2014 at 12:32 PM, Gerald Coley < > [email protected]> > >> >> wrote: > >> >> > SW is supposed to set it to 1.35V. Sounds like it got dropped > >> >> > somewhere > >> >> > because initially it did.. It was designed this way because when > it > >> >> > was > >> >> > designed, the PMIC defaulted to 1.5V. Since the design there is a > >> >> > TPS65217D > >> >> > that was release later that supports the 1.35V initial setting. > >> >> > >> >> It should be set here: > >> >> > >> >> > >> >> > >> >> > http://git.denx.de/?p=u-boot.git;a=blob;f=board/ti/am335x/board.c;h=0739e6021a21e71d7d0f5c840b793ce7fdf98fae;hb=HEAD#l275 > > >> >> > >> >> 269 /* > >> >> 270 * Increase USB current limit to 1300mA or > 1800mA > >> >> and > >> >> set > >> >> 271 * the MPU voltage controller as needed. > >> >> 272 */ > >> >> 273 if (dpll_mpu_opp100.m == MPUPLL_M_1000) { > >> >> 274 usb_cur_lim = > >> >> TPS65217_USB_INPUT_CUR_LIMIT_1800MA; > >> >> 275 mpu_vdd = TPS65217_DCDC_VOLT_SEL_1325MV; > >> >> 276 } else { > >> >> 277 usb_cur_lim = > >> >> TPS65217_USB_INPUT_CUR_LIMIT_1300MA; > >> >> 278 mpu_vdd = TPS65217_DCDC_VOLT_SEL_1275MV; > >> >> 279 } > >> >> > >> >> > >> >> But that only happens if you have the "beaglebone black" header in > >> >> eeprom: > >> >> > >> >> 262 /* > >> >> 263 * Override what we have detected since we know > if > >> >> we > >> >> have > >> >> 264 * a Beaglebone Black it supports 1GHz. > >> >> 265 */ > >> >> 266 if (board_is_bone_lt(&header)) > >> >> > >> >> So you'll have to override that check. > >> > > >> > > >> > Note that the question was about DCDC1 and DDR voltage not DCDC2/3 > (CORE > >> > and > >> > MPU) voltage. I don't know what initial bring-up U-Boot was whacking > >> > DCDC1 > >> > but it never reached the rest of the world so it's more a happy > accident > >> > that should be corrected (and wouldn't be too hard to do, if anyone > out > >> > there is looking for a reason to get their feet wet ). > >> > >> Well, the original v2013.04 patchset can be seen here: > >> > >> > >> > https://github.com/beagleboard/meta-beagleboard/tree/master/common-bsp/recipes-bsp/u-boot/u-boot-denx > > >> > >> The only thing that touches the pmic, is this hack: > >> > >> > >> > https://github.com/beagleboard/meta-beagleboard/blob/master/common-bsp/recipes-bsp/u-boot/u-boot-denx/0004-beaglebone-HACK-raise-USB-current-limit.patch > > >> > >> I don't have my tps decoder ring, so i'm not sure if that address is > >> more then just the usb current setting.. > > > > > > I believe the equivalent hack to set DCDC1 to 1.35V is > > > > > > +/* 0x24 is the address of the PMIC */ > > +/* 0x0b is the password register */ > > +/* 0x0e is the DEFDCDC1 register */ > > +/* 0x73 is the password (register 0x0e ^ 0x7d) */ > > +/* 0x12 sets the DCDC1 to 1.35V */ > > +/* Sequence must be repeated twice for password protection */ > > #define CONFIG_BOOTCOMMAND \ > > + "i2c mw 0x24 0x0b 0x73; " \ > > + "i2c mw 0x24 0x0e 0x12; " \ > > + "i2c mw 0x24 0x0b 0x73; " \ > > + "i2c mw 0x24 0x0e 0x12; " \ > > So I got this to work via this sequence in the terminal.. > > i2c dev 0; > i2c mw 0x24 0x0b 0x73; /* Password unlock 1 */ > i2c mw 0x24 0x0e 0x12; /* Set DCDC1 to 1.35V */ > i2c mw 0x24 0x0b 0x73; /* Password unlock 2 */ > i2c mw 0x24 0x0e 0x12; /* Set DCDC1 to 1.35V */ > i2c mw 0x24 0x0b 0x6c; /* Password unlock 1 */ > i2c mw 0x24 0x11 0x86; /* Apply DCDC changes */ > i2c mw 0x24 0x0b 0x6c; /* Password unlock 2 */ > i2c mw 0x24 0x11 0x86; /* Apply DCDC changes */ > > The L1/R6 test point is showing 1.35v >
Gerald noticed that the voltage went back to 1.5V after the kernel booted, so I've introduced a patch: http://builds.beagleboard.org/builders/runtests/builds/36 I've boot tested it, but don't have a meter with me to measure the voltage. I did, however, get confirmation from the kernel: root@beaglebone:~# cat /sys/class/regulator/regulator.3/name vdd_ddr root@beaglebone:~# cat /sys/class/regulator/regulator.3/ device/ min_microvolts power/ suspend_disk_state type max_microvolts name state suspend_mem_state uevent microvolts num_users subsystem/ suspend_standby_state root@beaglebone:~# cat /sys/class/regulator/regulator.3/microvolts 1350000 Hopefully we'll see improved power and EMI conditions with this update! > > Regards, > > > -- > Robert Nelson > http://www.rcn-ee.com/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
