AM3352: How to use MDIO BUS to read PHY registers in linux user space?

Hi Forum,

I'm currently using the power supply to power the control board for repetitive power-up tests.

When the network is normal (there is a network connection): the current consumption is about 0.334A
When the network is normal (no network connection): the current consumption is about 0.314A
When the network is abnormal (the two LED lights of RJ45 are always on when there is no network connection): the current consumption is about 0.283~0.285A

The above results show that when the network is abnormal, the PHY consumes almost no current (the missing 49mA is very close to the datasheet content of the PHY).
Although the chance of this happening is less than 1/200, I would like to find other ways to solve this problem.

Thanks.

Hi Forum,

The following is the content of dmesg:
(Under abnormal conditions, the content of dmesg is the same as under normal conditions.)

root@P-:/# dmesg
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 3.14.43 (xxxxxx@xxxxxx-VirtualBox) (gcc version 4.7.3 20130226 (prerelease) (crosstool-NG linaro-1.13.1-4.7-2013.03-20130313 - Linaro GCC 2013.03) ) #128 Fri Feb 17 16:57:41 CST 2023
[ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c5387d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] Machine model: TI AM335x EVM
[ 0.000000] Memory policy: Data cache writeback
[ 0.000000] On node 0 totalpages: 32512
[ 0.000000] free_area_init_node: node 0, pgdat c0695d64, node_mem_map c7dfa000
[ 0.000000] Normal zone: 256 pages used for memmap
[ 0.000000] Normal zone: 0 pages reserved
[ 0.000000] Normal zone: 32512 pages, LIFO batch:7
[ 0.000000] CPU: All CPU(s) started in SVC mode.
[ 0.000000] AM335X ES2.1 (neon )
[ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[ 0.000000] pcpu-alloc: [0] 0
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 32256
[ 0.000000] Kernel command line: console=ttyS0,115200n8 quiet lpj=741376 root=ubi0:rootfs rw ubi.mtd=NAND.rootfs,2048 rootfstype=ubifs rootwait=1 key_data=0
[ 0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[ 0.000000] Memory: 121796K/130048K available (4735K kernel code, 234K rwdata, 1540K rodata, 196K init, 242K bss, 8252K reserved, 0K highmem)
[ 0.000000] Virtual kernel memory layout:
[ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
[ 0.000000] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB)
[ 0.000000] vmalloc : 0xc8800000 - 0xff000000 ( 872 MB)
[ 0.000000] lowmem : 0xc0000000 - 0xc8000000 ( 128 MB)
[ 0.000000] pkmap : 0xbfe00000 - 0xc0000000 ( 2 MB)
[ 0.000000] modules : 0xbf000000 - 0xbfe00000 ( 14 MB)
[ 0.000000] .text : 0xc0008000 - 0xc0629004 (6277 kB)
[ 0.000000] .init : 0xc062a000 - 0xc065b064 ( 197 kB)
[ 0.000000] .data : 0xc065c000 - 0xc0696a80 ( 235 kB)
[ 0.000000] .bss : 0xc0696a80 - 0xc06d33e8 ( 243 kB)
[ 0.000000] NR_IRQS:16 nr_irqs:16 16
[ 0.000000] IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts
[ 0.000000] Total of 128 interrupts on 1 active controller
[ 0.000000] OMAP clockevent source: timer2 at 25000000 Hz
[ 0.000016] sched_clock: 32 bits at 25MHz, resolution 40ns, wraps every 171798691800ns
[ 0.000041] OMAP clocksource: timer1 at 25000000 Hz
[ 0.000360] Console: colour dummy device 80x30
[ 0.000405] Calibrating delay loop (skipped) preset value.. 296.55 BogoMIPS (lpj=741376)
[ 0.000426] pid_max: default: 32768 minimum: 301
[ 0.000546] Security Framework initialized
[ 0.000615] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.000631] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.010120] CPU: Testing write buffer coherency: ok
[ 0.010607] Setting up static identity map for 0x804a63d8 - 0x804a6430
[ 0.012037] devtmpfs: initialized
[ 0.014739] VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 3
[ 0.024081] omap_hwmod: tptc0 using broken dt data from edma
[ 0.024192] omap_hwmod: tptc1 using broken dt data from edma
[ 0.024322] omap_hwmod: tptc2 using broken dt data from edma
[ 0.027811] omap_hwmod: debugss: _wait_target_disable failed
[ 0.072428] pinctrl core: initialized pinctrl subsystem
[ 0.073915] regulator-dummy: no parameters
[ 0.074687] NET: Registered protocol family 16
[ 0.075484] DMA: preallocated 256 KiB pool for atomic coherent allocations
[ 0.078493] cpuidle: using governor ladder
[ 0.078512] cpuidle: using governor menu
[ 0.087193] syscon 44e10000.control_module: regmap [mem 0x44e10000-0x44e107fb] registered
[ 0.089344] platform 49000000.edma: alias fck already exists
[ 0.089377] platform 49000000.edma: alias fck already exists
[ 0.089398] platform 49000000.edma: alias fck already exists
[ 0.091005] OMAP GPIO hardware version 0.1
[ 0.105741] omap-gpmc 50000000.gpmc: could not find pctldev for node /pinmux@44e10800/nandflash_pins_default, deferring probe
[ 0.105786] platform 50000000.gpmc: Driver omap-gpmc requests probe deferral
[ 0.108752] hw-breakpoint: debug architecture 0x4 unsupported.
[ 0.140308] bio: create slab at 0
[ 0.162921] edma-dma-engine edma-dma-engine.0: TI EDMA DMA engine driver
[ 0.164681] SCSI subsystem initialized
[ 0.166194] usbcore: registered new interface driver usbfs
[ 0.166492] usbcore: registered new interface driver hub
[ 0.166833] usbcore: registered new device driver usb
[ 0.168848] pps_core: LinuxPPS API ver. 1 registered
[ 0.168867] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti giometti@linux.it
[ 0.169088] PTP clock support registered
[ 0.171340] omap-mailbox 480c8000.mailbox: omap mailbox rev 0x400
[ 0.173377] Switched to clocksource timer1
[ 0.173715] FS-Cache: Loaded
[ 0.203393] NET: Registered protocol family 2
[ 0.204726] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.204759] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.204785] TCP: Hash tables configured (established 1024 bind 1024)
[ 0.204870] TCP: reno registered
[ 0.204892] UDP hash table entries: 256 (order: 0, 4096 bytes)
[ 0.204917] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[ 0.205180] NET: Registered protocol family 1
[ 0.205701] RPC: Registered named UNIX socket transport module.
[ 0.205717] RPC: Registered udp transport module.
[ 0.205726] RPC: Registered tcp transport module.
[ 0.205736] RPC: Registered tcp NFSv4.1 backchannel transport module.
[ 0.210137] futex hash table entries: 256 (order: -1, 3072 bytes)
[ 0.211907] VFS: Disk quotas dquot_6.5.2
[ 0.211982] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[ 0.212729] NFS: Registering the id_resolver key type
[ 0.212824] Key type id_resolver registered
[ 0.212837] Key type id_legacy registered
[ 0.213169] Key type cifs.spnego registered
[ 0.213193] jffs2: version 2.2. (NAND) (SUMMARY) c 2001-2006 Red Hat, Inc.
[ 0.213421] msgmni has been set to 237
[ 0.215886] NET: Registered protocol family 38
[ 0.215944] io scheduler noop registered (default)
[ 0.215957] io scheduler deadline registered
[ 0.215988] io scheduler cfq registered
[ 0.218308] pinctrl-single 44e10800.pinmux: 142 pins at pa f9e10800 size 568
[ 0.223462] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[ 0.227506] 44e09000.serial: ttyS0 at MMIO 0x44e09000 (irq = 88, base_baud = 3000000) is a 8250
[ 0.228064] console [ttyS0] enabled
[ 0.229726] 48022000.serial: ttyS1 at MMIO 0x48022000 (irq = 89, base_baud = 3000000) is a 8250
[ 0.231647] omap_rng 48310000.rng: OMAP Random Number Generator ver. 20
[ 0.232326] GPIO: vbus1_rst.
[ 0.232706] GPIO: breaker.
[ 0.233122] GPIO: Phy-RST.
[ 0.233501] GPIO: GPIO-JTAG.
[ 0.233797] [drm] Initialized drm 1.1.0 20060810
[ 0.234295] loop: module loaded
[ 0.234718] (hci_tty): inside hci_tty_init
[ 0.235373] (hci_tty): allocated 250, 0
[ 0.250318] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 0.250342] ehci-platform: EHCI generic platform driver
[ 0.250693] ehci-omap: OMAP-EHCI Host Controller driver
[ 0.251022] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 0.251063] ohci-platform: OHCI generic platform driver
[ 0.252312] usbcore: registered new interface driver cdc_acm
[ 0.252328] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[ 0.252642] usbcore: registered new interface driver usb-storage
[ 0.253236] usbcore: registered new interface driver usbserial
[ 0.253505] usbcore: registered new interface driver usbserial_generic
[ 0.253757] usbserial: USB Serial support registered for generic
[ 0.256763] 47401300.usb-phy supply vcc not found, using dummy regulator
[ 0.259085] musb-hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk split, HB-ISO Rx, HB-ISO Tx, SoftConn)
[ 0.259110] musb-hdrc: MHDRC RTL version 2.0
[ 0.259122] musb-hdrc: setup fifo_mode 4
[ 0.259147] musb-hdrc: 28/31 max ep, 16384/16384 memory
[ 0.259345] musb-hdrc musb-hdrc.0.auto: MUSB HDRC host driver
[ 0.259392] musb-hdrc musb-hdrc.0.auto: new USB bus registered, assigned bus number 1
[ 0.259695] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[ 0.259716] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 0.259733] usb usb1: Product: MUSB HDRC host driver
[ 0.259749] usb usb1: Manufacturer: Linux 3.14.43 musb-hcd
[ 0.259763] usb usb1: SerialNumber: musb-hdrc.0.auto
[ 0.261276] hub 1-0:1.0: USB hub found
[ 0.261359] hub 1-0:1.0: 1 port detected
[ 0.262766] 47401b00.usb-phy supply vcc not found, using dummy regulator
[ 0.265032] musb-hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine, bulk split, HB-ISO Rx, HB-ISO Tx, SoftConn)
[ 0.265053] musb-hdrc: MHDRC RTL version 2.0
[ 0.265065] musb-hdrc: setup fifo_mode 4
[ 0.265084] musb-hdrc: 28/31 max ep, 16384/16384 memory
[ 0.288707] omap_rtc 44e3e000.rtc: rtc core: registered 44e3e000.rtc as rtc0
[ 0.289540] i2c /dev entries driver
[ 0.291417] softdog: Software Watchdog Timer: 0.08 initialized. soft_noboot=0 soft_margin=60 sec soft_panic=0 (nowayout=0)
[ 0.291438] cpufreq_stats_init: 0
[ 0.291450] cpufreq_stats_create_table:
[ 0.292197] pinctrl-single 44e10800.pinmux: mux offset out of range: 0x860 (0x238)
[ 0.299867] pinctrl-single 44e10800.pinmux: could not add functions for user_leds_default 2144x
[ 0.308742] pinctrl-single 44e10800.pinmux: mux offset out of range: 0x860 (0x238)
[ 0.316392] pinctrl-single 44e10800.pinmux: could not add functions for user_leds_sleep 2144x
[ 0.327737] omap-aes 53500000.aes: OMAP AES hw accel rev: 3.2
[ 0.329649] omap-sham 53100000.sham: hw accel on OMAP rev 4.3
[ 0.331561] hidraw: raw HID events driver (C) Jiri Kosina
[ 0.332217] usbcore: registered new interface driver usbhid
[ 0.332230] usbhid: USB HID core driver
[ 0.333061] TCP: cubic registered
[ 0.333078] Initializing XFRM netlink socket
[ 0.333104] NET: Registered protocol family 17
[ 0.333169] NET: Registered protocol family 15
[ 0.333329] Key type dns_resolver registered
[ 0.334607] setting to 600000 kHz because of event 1
[ 0.334628] setting to 600000 kHz because of event 3
[ 0.335427] PM: Voltage scaling data blob not provided from DT.
[ 0.335553] PM: bootloader does not support rtc-only!
[ 0.335568] ThumbEE CPU extension supported.
[ 0.335612] Registering SWP/SWPB emulation handler
[ 0.337765] regulator-dummy: disabling
[ 0.340004] omap-gpmc 50000000.gpmc: GPMC revision 6.0
[ 0.340030] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
[ 0.340299] gpmc: nand_init gpmc_cs_request GPMC CS 0 to 0x00000000
[ 0.346663] gpmc: nand_init gpmc_cs_request GPMC CS 0 to 0x01000000
[ 0.354009] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xf1
[ 0.354030] nand: Micron MT29F1G08ABAEAH4
[ 0.354044] nand: 128MiB, SLC, page size: 2048, OOB size: 64
[ 0.354056] nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme
[ 0.354684] 14 ofpart partitions found on MTD device omap2-nand.0
[ 0.354701] Creating 14 MTD partitions on "omap2-nand.0":
[ 0.354725] 0x000000000000-0x000000020000 : "NAND.spl"
[ 0.357058] 0x000000020000-0x000000040000 : "NAND.spl.backup1"
[ 0.359208] 0x000000040000-0x000000060000 : "NAND.spl.backup2"
[ 0.361357] 0x000000060000-0x000000080000 : "NAND.spl.backup3"
[ 0.363485] 0x000000080000-0x000000180000 : "NAND.u-boot"
[ 0.366051] 0x000000180000-0x0000001a0000 : "NAND.env"
[ 0.368147] 0x0000001a0000-0x0000001c0000 : "NAND.env.backup"
[ 0.370225] 0x0000001c0000-0x000000200000 : "NAND.dtb"
[ 0.372308] 0x000000200000-0x000000400000 : "NAND.screen"
[ 0.375609] 0x000000400000-0x000000600000 : "NAND.other"
[ 0.378504] 0x000000600000-0x000000c00000 : "NAND.kernel"
[ 0.383173] 0x000000c00000-0x000003400000 : "NAND.rootfs"
[ 0.402114] 0x000003400000-0x000004800000 : "NAND.user"
[ 0.412674] 0x000004800000-0x000007000000 : "NAND.test"
[ 0.433756] UBI: attaching mtd11 to ubi0
[ 0.598459] UBI: scanning is finished
[ 0.605257] UBI warning: print_rsvd_warning: cannot reserve enough PEBs for bad PEB handling, reserved 18, need 20
[ 0.606833] UBI: attached mtd11 (name "NAND.rootfs", size 40 MiB) to ubi0
[ 0.606852] UBI: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes
[ 0.606865] UBI: min./max. I/O unit sizes: 2048/2048, sub-page size 512
[ 0.606876] UBI: VID header offset: 2048 (aligned 2048), data offset: 4096
[ 0.606887] UBI: good PEBs: 320, bad PEBs: 0, corrupted PEBs: 0
[ 0.606898] UBI: user volume: 1, internal volumes: 1, max. volumes count: 128
[ 0.606913] UBI: max/mean erase counter: 3/1, WL threshold: 4096, image sequence number: 700327315
[ 0.606925] UBI: available PEBs: 0, total reserved PEBs: 320, PEBs reserved for bad PEB handling: 18
[ 0.607886] UBI: background thread "ubi_bgt0d" started, PID 721
[ 0.654254] davinci_mdio 4a101000.mdio: davinci mdio revision 1.6
[ 0.654279] davinci_mdio 4a101000.mdio: detected phy mask fffffffc
[ 0.656090] libphy: 4a101000.mdio: probed
[ 0.656122] davinci_mdio 4a101000.mdio: phy[0]: device 4a101000.mdio:00, driver Micrel KSZ8081 or KSZ8091
[ 0.656140] davinci_mdio 4a101000.mdio: phy[1]: device 4a101000.mdio:01, driver Micrel KSZ8081 or KSZ8091
[ 0.656963] cpsw 4a100000.ethernet: Detected MACID = 08:11:23:32:12:79
[ 0.658978] omap_rtc 44e3e000.rtc: setting system clock to 2000-01-01 00:00:01 UTC (946684801)
[ 0.679731] UBIFS: background thread "ubifs_bgt0_0" started, PID 735
[ 0.695277] UBIFS: recovery needed
[ 0.783528] UBIFS: recovery completed
[ 0.783696] UBIFS: mounted UBI device 0, volume 0, name "rootfs"
[ 0.783711] UBIFS: LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[ 0.783728] UBIFS: FS size: 36569088 bytes (34 MiB, 288 LEBs), journal size 5332992 bytes (5 MiB, 42 LEBs)
[ 0.783739] UBIFS: reserved for root: 0 bytes (0 KiB)
[ 0.783759] UBIFS: media format: w4/r0 (latest is w4/r0), UUID 4B6E6EE5-625B-4635-B89C-CCCDE0B4FEEA, small LPT model
[ 0.785170] VFS: Mounted root (ubifs filesystem) on device 0:12.
[ 0.786048] devtmpfs: mounted
[ 0.786491] Freeing unused kernel memory: 196K (c062a000 - c065b000)
[ 1.144974] UBI: attaching mtd12 to ubi1
[ 1.190962] UBI: scanning is finished
[ 1.197547] UBI warning: print_rsvd_warning: cannot reserve enough PEBs for bad PEB handling, reserved 9, need 20
[ 1.209368] UBI: attached mtd12 (name "NAND.user", size 20 MiB) to ubi1
[ 1.209393] UBI: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
[ 1.209406] UBI: min./max. I/O unit sizes: 2048/2048, sub-page size 512
[ 1.209418] UBI: VID header offset: 512 (aligned 512), data offset: 2048
[ 1.209428] UBI: good PEBs: 160, bad PEBs: 0, corrupted PEBs: 0
[ 1.209440] UBI: user volume: 1, internal volumes: 1, max. volumes count: 128
[ 1.209455] UBI: max/mean erase counter: 3/1, WL threshold: 4096, image sequence number: 777286643
[ 1.209466] UBI: available PEBs: 0, total reserved PEBs: 160, PEBs reserved for bad PEB handling: 9
[ 1.211905] UBI: background thread "ubi_bgt1d" started, PID 757
[ 1.253812] UBIFS: background thread "ubifs_bgt1_0" started, PID 761
[ 1.281288] UBIFS: recovery needed
[ 1.323899] UBIFS: recovery completed
[ 1.324064] UBIFS: mounted UBI device 1, volume 0, name "user"
[ 1.324081] UBIFS: LEB size: 129024 bytes (126 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[ 1.324098] UBIFS: FS size: 17676288 bytes (16 MiB, 137 LEBs), journal size 5160960 bytes (4 MiB, 40 LEBs)
[ 1.324109] UBIFS: reserved for root: 0 bytes (0 KiB)
[ 1.324129] UBIFS: media format: w4/r0 (latest is w4/r0), UUID 392C4593-0608-4788-918C-ED91EF9DEE06, small LPT model
[ 1.342868] UBI: attaching mtd13 to ubi2
[ 1.434518] UBI: scanning is finished
[ 1.454359] UBI: attached mtd13 (name "NAND.test", size 40 MiB) to ubi2
[ 1.454383] UBI: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
[ 1.454396] UBI: min./max. I/O unit sizes: 2048/2048, sub-page size 512
[ 1.454407] UBI: VID header offset: 512 (aligned 512), data offset: 2048
[ 1.454418] UBI: good PEBs: 320, bad PEBs: 0, corrupted PEBs: 0
[ 1.454429] UBI: user volume: 1, internal volumes: 1, max. volumes count: 128
[ 1.454444] UBI: max/mean erase counter: 2/1, WL threshold: 4096, image sequence number: 1497644200
[ 1.454456] UBI: available PEBs: 0, total reserved PEBs: 320, PEBs reserved for bad PEB handling: 20
[ 1.455376] UBI: background thread "ubi_bgt2d" started, PID 770
[ 1.498077] UBIFS: background thread "ubifs_bgt2_0" started, PID 774
[ 1.522712] UBIFS: recovery needed
[ 1.546481] UBIFS: recovery completed
[ 1.546649] UBIFS: mounted UBI device 2, volume 0, name "test"
[ 1.546665] UBIFS: LEB size: 129024 bytes (126 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[ 1.546682] UBIFS: FS size: 36900864 bytes (35 MiB, 286 LEBs), journal size 5160960 bytes (4 MiB, 40 LEBs)
[ 1.546694] UBIFS: reserved for root: 0 bytes (0 KiB)
[ 1.546714] UBIFS: media format: w4/r0 (latest is w4/r0), UUID CAF81A2C-E916-4FB2-95AA-80ACBD9F3D5A, small LPT model
[ 1.562226] net eth0: initializing cpsw version 1.12 (0)
[ 1.624503] net eth0: phy found : id is : 0x221561
[ 4.420441] g_serial gadget: Gadget Serial v2.4
[ 4.420469] g_serial gadget: g_serial ready

Thanks.

Hi Forum, 

Seeing the discussion below, I made the modification (cpsw.c) that Rainer replied last, and finally I can use ioctrl to access the PHY in user space.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/346597/am335x-mdio-linux

It is currently possible to directly access the PHY using mdio-tool. (phytool should also work, I haven't tried it yet)

Thanks.