> Date: Tue, 20 Sep 2022 14:04:14 +0000
> From: Miod Vallat <[email protected]>
>
> I recently installed OpenBSD to a PandaBoard (the original, not
> PandaBoard ES) and noticed that the clock was very quickly getting
> behind, with ntpd unable to cope.
>
> The following extremely crude diff fixes it, but probably at the expense
> of breaking other omap systems. Is there a better way to figure out what
> is the real system clock frequency?
Hmm, in the device tree world it appears that there should be a node
with a "arm,cortex-a9-global-timer" compatible string that references
a clock which will provide the actual frequency the clock is running
at.
However, I don't think the omap4 device trees have such a node. I
think this means that Linux doesn't actually use the global timer and
uses the private timer instead. That timer is represented in the
device tree by a node with the "arm,cortex-a9-twd-timer" compatible.
I think jsg@ is right. The clock rate will be the output rate of
mpu_periphclk. It looks like that clock has a clock-output-names
property that could be used to look up the frequency, although we
currently don't have any infrastructure to look up clocks by name.
> Index: sys/arch/armv7/omap/omapid.c
> ===================================================================
> RCS file: /OpenBSD/src/sys/arch/armv7/omap/omapid.c,v
> retrieving revision 1.5
> diff -u -p -u -p -r1.5 omapid.c
> --- sys/arch/armv7/omap/omapid.c 24 Oct 2021 17:52:27 -0000 1.5
> +++ sys/arch/armv7/omap/omapid.c 20 Sep 2022 13:54:01 -0000
> @@ -83,9 +83,12 @@ omapid_attach(struct device *parent, str
> rev = bus_space_read_4(sc->sc_iot, sc->sc_ioh, O4_ID_CODE);
> switch ((rev >> 12) & 0xffff) {
> case 0xB852:
> - case 0xB95C:
> board = "omap4430";
> newclockrate = 400 * 1000 * 1000;
> + break;
> + case 0xB95C:
> + board = "omap4430";
> + newclockrate = 300 * 1000 * 1000;
> break;
> case 0xB94E:
> board = "omap4460";
>
>
>
> OpenBSD 7.2 (GENERIC) #11: Tue Sep 20 13:18:51 GMT 2022
> [email protected]:/usr/src/sys/arch/armv7/compile/GENERIC
> real mem = 1021243392 (973MB)
> avail mem = 992374784 (946MB)
> random: boothowto does not indicate good seed
> mainbus0 at root: TI OMAP4 PandaBoard
> cpu0 at mainbus0 mpidr 0: ARM Cortex-A9 r1p2
> cpu0: 32KB 32b/line 4-way L1 VIPT I-cache, 32KB 32b/line 4-way L1 D-cache
> cortex0 at mainbus0
> amptimer0 at cortex0: 396000 kHz
> armliicc0 at cortex0: rtl 4 waymask: 0x0000000f
> omap0 at mainbus0
> omapid0 at omap0: omap4430
> amptimer0: adjusting clock: new rate 300000 kHz
> prcm0 at omap0 rev 0.0
> ampintc0 at mainbus0 nirq 160, ncpu 2: "interrupt-controller"
> omwugen0 at mainbus0
> simplebus0 at mainbus0: "ocp"
> omsysc0 at simplebus0: "target-module"
> omsysc1 at simplebus0: "target-module"
> omsysc2 at simplebus0: "target-module"
> omsysc3 at simplebus0: "target-module"
> omsysc4 at simplebus0: "target-module"
> omsysc5 at simplebus0: "target-module"
> omsysc6 at simplebus0: "target-module"
> simplebus1 at simplebus0: "l4"
> simplebus2 at simplebus1: "cm1"
> omcm0 at simplebus2: "mpuss_cm"
> omclock0 at omcm0: "clk"
> omcm1 at simplebus2: "tesla_cm"
> omclock1 at omcm1: "clk"
> omcm2 at simplebus2: "abe_cm"
> omclock2 at omcm2: "clk"
> simplebus3 at simplebus1: "cm2"
> omcm3 at simplebus3: "l4_ao_cm"
> omclock3 at omcm3: "clk"
> omcm4 at simplebus3: "l3_1_cm"
> omclock4 at omcm4: "clk"
> omcm5 at simplebus3: "l3_2_cm"
> omclock5 at omcm5: "clk"
> omcm6 at simplebus3: "ducati_cm"
> omclock6 at omcm6: "clk"
> omcm7 at simplebus3: "l3_dma_cm"
> omclock7 at omcm7: "clk"
> omcm8 at simplebus3: "l3_emif_cm"
> omclock8 at omcm8: "clk"
> omcm9 at simplebus3: "d2d_cm"
> omclock9 at omcm9: "clk"
> omcm10 at simplebus3: "l4_cfg_cm"
> omclock10 at omcm10: "clk"
> omcm11 at simplebus3: "l3_instr_cm"
> omclock11 at omcm11: "clk"
> omcm12 at simplebus3: "ivahd_cm"
> omclock12 at omcm12: "clk"
> omcm13 at simplebus3: "iss_cm"
> omclock13 at omcm13: "clk"
> omcm14 at simplebus3: "l3_dss_cm"
> omclock14 at omcm14: "clk"
> omcm15 at simplebus3: "l3_gfx_cm"
> omclock15 at omcm15: "clk"
> omcm16 at simplebus3: "l3_init_cm"
> omclock16 at omcm16: "clk"
> omcm17 at simplebus3: "l4_per_cm"
> omclock17 at omcm17: "clk"
> simplebus4 at simplebus1: "scm"
> syscon0 at simplebus4: "scm_conf"
> simplebus5 at simplebus1: "scm"
> syscon1 at simplebus5: "omap4_padconf_global"
> pinctrl0 at simplebus5
> simplebus6 at simplebus1: "l4"
> "counter" at simplebus6 not configured
> "prm" at simplebus6 not configured
> "scrm" at simplebus6 not configured
> "scm" at simplebus6 not configured
> simplebus7 at simplebus6: "padconf"
> pinctrl1 at simplebus7
> "ocmcram" at simplebus0 not configured
> "dma-controller" at simplebus0 not configured
> omgpio0 at simplebus0: rev 0.1
> gpio0 at omgpio0: 32 pins
> omgpio1 at simplebus0: rev 0.1
> gpio1 at omgpio1: 32 pins
> omgpio2 at simplebus0: rev 0.1
> gpio2 at omgpio2: 32 pins
> omgpio3 at simplebus0: rev 0.1
> gpio3 at omgpio3: 32 pins
> omgpio4 at simplebus0: rev 0.1
> gpio4 at omgpio4: 32 pins
> omgpio5 at simplebus0: rev 0.1
> gpio5 at omgpio5: 32 pins
> "gpmc" at simplebus0 not configured
> com0 at simplebus0: ti16750, 64 byte fifo
> com0: probed fifo depth: 0 bytes
> com1 at simplebus0: ti16750, 64 byte fifo
> com1: probed fifo depth: 0 bytes
> com2 at simplebus0: ti16750, 64 byte fifo
> com2: console
> com3 at simplebus0: ti16750, 64 byte fifo
> com3: probed fifo depth: 0 bytes
> omsysc7 at simplebus0: "target-module"
> "smartreflex" at omsysc7 not configured
> omsysc8 at simplebus0: "target-module"
> "smartreflex" at omsysc8 not configured
> omsysc9 at simplebus0: "target-module"
> "smartreflex" at omsysc9 not configured
> "spinlock" at simplebus0 not configured
> tiiic0 at simplebus0 rev 0.10
> iic0 at tiiic0
> "ti,twl6030" at iic0 addr 0x48 not configured
> "ti,twl6040" at iic0 addr 0x4b not configured
> tiiic1 at simplebus0 rev 0.10
> iic1 at tiiic1
> tiiic2 at simplebus0 rev 0.10
> iic2 at tiiic2
> "ti,eeprom" at iic2 addr 0x50 not configured
> tiiic3 at simplebus0 rev 0.10
> iic3 at tiiic3
> "spi" at simplebus0 not configured
> "spi" at simplebus0 not configured
> "1w" at simplebus0 not configured
> "spi" at simplebus0 not configured
> "spi" at simplebus0 not configured
> ommmc0 at simplebus0
> sdmmc0 at ommmc0: 8-bit
> ommmc1 at simplebus0
> sdmmc1 at ommmc1: 1-bit
> "hsi" at simplebus0 not configured
> "mmu" at simplebus0 not configured
> "mmu" at simplebus0 not configured
> omdog0 at simplebus0 rev 0.0
> omdog1 at simplebus0 rev 0.0
> "mcpdm" at simplebus0 not configured
> "mcbsp" at simplebus0 not configured
> "keypad" at simplebus0 not configured
> "dmm" at simplebus0 not configured
> "emif" at simplebus0 not configured
> "emif" at simplebus0 not configured
> "ocp2scp" at simplebus0 not configured
> "mailbox" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "timer" at simplebus0 not configured
> "usbhstll" at simplebus0 not configured
> omehci0 at simplebus0
> usb0 at omehci0: USB revision 2.0
> uhub0 at usb0 configuration 1 interface 0 "TI OMAP EHCI root hub" rev
> 2.00/1.00 addr 1
> "control-phy" at simplebus0 not configured
> "control-phy" at simplebus0 not configured
> "usb_otg_hs" at simplebus0 not configured
> "aes" at simplebus0 not configured
> "aes" at simplebus0 not configured
> "des" at simplebus0 not configured
> "sham" at simplebus0 not configured
> "regulator-abb-mpu" at simplebus0 not configured
> "dss" at simplebus0 not configured
> "bandgap" at simplebus0 not configured
> sdmmc1: can't supply clock
> sdmmc1: can't enable card
> scsibus0 at sdmmc0: 2 targets, initiator 0
> sd0 at scsibus0 targ 1 lun 0: <SD/MMC, SU08G, 0080> removable
> sd0: 7580MB, 512 bytes/sector, 15523840 sectors
> uhub1 at uhub0 port 1 configuration 1 interface 0 "Standard Microsystems
> product 0x9514" rev 2.00/1.00 addr 2
> smsc0 at uhub1 port 1 configuration 1 interface 0 "Standard Microsystems
> SMSC9512/14" rev 2.00/1.00 addr 3
> smsc0: address 02:04:01:eb:19:20
> ukphy0 at smsc0 phy 1: Generic IEEE 802.3u media interface, rev. 3: OUI
> 0x0001f0, model 0x000c
> umass0 at uhub1 port 3 configuration 1 interface 0 "Generic Externa" rev
> 2.10/0.56 addr 4
> umass0: using SCSI over Bulk-Only
> scsibus1 at umass0: 2 targets, initiator 0
> sd1 at scsibus1 targ 1 lun 0: <Generic, Externa, 0056>
> serial.88887777222222220138
> sd1: 228936MB, 512 bytes/sector, 468862127 sectors
> vscsi0 at root
> scsibus2 at vscsi0: 256 targets
> softraid0 at root
> scsibus3 at softraid0: 256 targets
> bootfile: sd0a:/bsd
> boot device: sd0
> root device (default sd0a): sd1a
> swap device (default sd1b):
> root on sd1a swap on sd1b dump on sd1b
> WARNING: CHECK AND RESET THE DATE!
>
>
