我在我的 Raspberry Pi 计算模块 4 中运行带有桌面的 Raspberry Pi OS（发布日期：2021 年 1 月 11 日）。
pi@raspberrypi:~ $ uname -a
Linux raspberrypi 5.10.16-v7l #1 SMP Tue Feb 23 19:01:18 CST 2021 armv7l GNU/Linux
它有一个 mini PCI express 插槽，我打算用它来安装 4 端口 UART 卡。我有一张 Diamond systems 的卡，它使用 EXAR XR17V354 UART 芯片。
作为一个乐观主义者，我插入卡并启动，希望获得最好的结果。
看起来该卡已被识别：
pi@raspberrypi:~ $ sudo lspci -v
00:00.0 PCI bridge: Broadcom Limited Device 2711 (rev 20) (prog-if 00 [Normal decode])
Flags: bus master, fast devsel, latency 0, IRQ 62
Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
I/O behind bridge: 00000000-00000fff
Memory behind bridge: c0000000-c00fffff
Capabilities: [48] Power Management version 3
Capabilities: [ac] Express Root Port (Slot-), MSI 00
Capabilities: [100] Advanced Error Reporting
Capabilities: [180] Vendor Specific Information: ID=0000 Rev=0 Len=028 <?>
Capabilities: [240] L1 PM Substates
Kernel driver in use: pcieport
01:00.0 Serial controller: Exar Corp. Device 0354 (rev 03) (prog-if 02 [16550])
Flags: bus master, fast devsel, latency 0, IRQ 62
Memory at 600000000 (32-bit, non-prefetchable) [size=16K]
Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [78] Power Management version 3
Capabilities: [80] Express Endpoint, MSI 01
Capabilities: [100] Virtual Channel
Kernel driver in use: exar_serial
但是，dmesg 没有提及在启动时创建的 tty。dmesg 说：（无法注册串行端口 0，irq 62，类型 2，错误 -28）
[ 1.158476] gpio-507 (ant1): hogged as output/high
[ 1.159913] gpio-511 (ant2): hogged as output/low
[ 1.161483] brcm-pcie fd500000.pcie: host bridge /scb/pcie@7d500000 ranges:
[ 1.161515] brcm-pcie fd500000.pcie: No bus range found for /scb/pcie@7d500000, using [bus 00-ff]
[ 1.161596] brcm-pcie fd500000.pcie: MEM 0x0600000000..0x063fffffff -> 0x00c0000000
[ 1.161686] brcm-pcie fd500000.pcie: IB MEM 0x0000000000..0x00ffffffff -> 0x0400000000
[ 1.215595] brcm-pcie fd500000.pcie: link up, 2.5 GT/s PCIe x1 (SSC)
[ 1.215784] brcm-pcie fd500000.pcie: PCI host bridge to bus 0000:00
[ 1.215806] pci_bus 0000:00: root bus resource [bus 00-ff]
[ 1.215827] pci_bus 0000:00: root bus resource [mem 0x600000000-0x63fffffff] (bus address [0xc0000000-0xffffffff])
[ 1.215917] pci 0000:00:00.0: [14e4:2711] type 01 class 0x060400
[ 1.216164] pci 0000:00:00.0: PME# supported from D0 D3hot
[ 1.219565] PCI: bus0: Fast back to back transfers disabled
[ 1.219590] pci 0000:00:00.0: bridge configuration invalid ([bus ff-ff]), reconfiguring
[ 1.219850] pci 0000:01:00.0: [13a8:0354] type 00 class 0x070002
[ 1.219912] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x00003fff]
[ 1.220231] pci 0000:01:00.0: PME# supported from D0 D3hot
[ 1.223525] PCI: bus1: Fast back to back transfers disabled
[ 1.223547] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
[ 1.223591] pci 0000:00:00.0: BAR 8: assigned [mem 0x600000000-0x6000fffff]
[ 1.223614] pci 0000:01:00.0: BAR 0: assigned [mem 0x600000000-0x600003fff]
[ 1.223641] pci 0000:00:00.0: PCI bridge to [bus 01]
[ 1.223667] pci 0000:00:00.0: bridge window [mem 0x600000000-0x6000fffff]
[ 1.224070] pcieport 0000:00:00.0: enabling device (0140 -> 0142)
[ 1.224303] pcieport 0000:00:00.0: PME: Signaling with IRQ 62
[ 1.230787] exar_serial 0000:01:00.0: enabling device (0140 -> 0142)
[ 1.231081] exar_serial 0000:01:00.0: Couldn't register serial port 0, irq 62, type 2, error -28
[ 1.233559] iproc-rng200 fe104000.rng: hwrng registered
[ 1.233875] vc-mem: phys_addr:0x00000000 mem_base=0x3ec00000 mem_size:0x40000000(1024 MiB)
[ 1.234792] gpiomem-bcm2835 fe200000.gpiomem: Initialised: Registers at 0xfe200000
然后我尝试使用 xr17v354 官方驱动程序。
- 解除本机串行驱动程序的绑定
root@raspberrypi:/home/pi# lspci -vd 13a8:*
01:00.0 Serial controller: Exar Corp. Device 0354 (rev 03) (prog-if 02 [16550])
Flags: bus master, fast devsel, latency 0, IRQ 62
Memory at 600000000 (32-bit, non-prefetchable) [size=16K]
Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [78] Power Management version 3
Capabilities: [80] Express Endpoint, MSI 01
Capabilities: [100] Virtual Channel
Kernel driver in use: exar_serial
root@raspberrypi:/home/pi# ls /sys/bus/pci/drivers/exar_serial/
0000:01:00.0 bind new_id remove_id uevent unbind
root@raspberrypi:/home/pi# echo -n "0000:01:00.0" > /sys/bus/pci/drivers/exar_serial/unbind
root@raspberrypi:/home/pi# lspci -vd 13a8:*
01:00.0 Serial controller: Exar Corp. Device 0354 (rev 03) (prog-if 02 [16550])
Flags: fast devsel, IRQ 62
Memory at 600000000 (32-bit, non-prefetchable) [size=16K]
Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [78] Power Management version 3
Capabilities: [80] Express Endpoint, MSI 01
Capabilities: [100] Virtual Channel
- 制作并安装自定义 (MaxLinear) Linux 驱动程序
root@raspberrypi:/home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6# make
make -C /home/pi/Desktop/linux-rpi-5.10.y M=/home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6 modules ARCH=arm
make[1]: Entering directory '/home/pi/Desktop/linux-rpi-5.10.y'
CC [M] /home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6/xr17v35x.o
MODPOST /home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6/Module.symvers
CC [M] /home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6/xr17v35x.mod.o
LD [M] /home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6/xr17v35x.ko
make[1]: Leaving directory '/home/pi/Desktop/linux-rpi-5.10.y'
root@raspberrypi:/home/pi/Desktop/xr17-lnx2.6.32-and-newer-pak_ver2.6# insmod xr17v35x.ko
它也无法创建 tty 设备。dmesg 显示：
[ 2377.605398] xr17v35x: loading out-of-tree module taints kernel.
[ 2377.606875] Exar PCIe (XR17V35x) serial driver Revision: 2.6
[ 2377.607409] ------------[ cut here ]------------
[ 2377.607454] WARNING: CPU: 0 PID: 1155 at arch/arm/mm/ioremap.c:287 __arm_ioremap_pfn_caller+0x1f4/0x218
[ 2377.607470] Modules linked in: xr17v35x(O+) fuse sha256_generic cfg80211 rfkill 8021q garp stp llc vc4 cec drm_kms_helper v3d gpu_sched raspberrypi_hwmon bcm2835_isp(C) bcm2835_codec(C) bcm2835_v4l2(C) v4l2_mem2mem bcm2835_mmal_vchiq(C) drm videobuf2_dma_contig videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc vc_sm_cma(C) snd_bcm2835(C) rpivid_mem drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd syscopyarea sysfillrect sysimgblt fb_sys_fops backlight uio_pdrv_genirq uio i2c_dev ip_tables x_tables ipv6
[ 2377.608186] CPU: 0 PID: 1155 Comm: insmod Tainted: G C O 5.10.16-v7l #1
[ 2377.608196] Hardware name: BCM2711
[ 2377.608208] Backtrace:
[ 2377.608243] [<c0b63178>] (dump_backtrace) from [<c0b63508>] (show_stack+0x20/0x24)
[ 2377.608259] r7:ffffffff r6:00000000 r5:60000013 r4:c12e69fc
[ 2377.608280] [<c0b634e8>] (show_stack) from [<c0b678a0>] (dump_stack+0xcc/0xf8)
[ 2377.608300] [<c0b677d4>] (dump_stack) from [<c0220b8c>] (__warn+0xfc/0x114)
[ 2377.608316] r10:c0eb1098 r9:00000009 r8:c0217a2c r7:0000011f r6:00000009 r5:c0217a2c
[ 2377.608327] r4:c0e1b020 r3:c1205094
[ 2377.608345] [<c0220a90>] (__warn) from [<c0b63c78>] (warn_slowpath_fmt+0x70/0xd8)
[ 2377.608358] r7:0000011f r6:c0e1b020 r5:c1205048 r4:00000000
[ 2377.608378] [<c0b63c0c>] (warn_slowpath_fmt) from [<c0217a2c>] (__arm_ioremap_pfn_caller+0x1f4/0x218)
[ 2377.608393] r9:00000000 r8:00000000 r7:00000000 r6:00000001 r5:00000000 r4:00004000
[ 2377.608412] [<c0217838>] (__arm_ioremap_pfn_caller) from [<c0217abc>] (__arm_ioremap_caller+0x6c/0x74)
[ 2377.608428] r10:03b9aca0 r9:00000006 r8:c42ba000 r7:00000000 r6:00003fff r5:00000000
[ 2377.608438] r4:00000000
[ 2377.608454] [<c0217a50>] (__arm_ioremap_caller) from [<c0217b1c>] (ioremap+0x30/0x38)
[ 2377.608467] r7:00000000 r6:00000000 r5:00000000 r4:c0217a50
[ 2377.608502] [<c0217aec>] (ioremap) from [<bf46910c>] (pci_default_setup+0xf8/0x114 [xr17v35x])
[ 2377.608512] r4:c4b2bab8
[ 2377.608546] [<bf469014>] (pci_default_setup [xr17v35x]) from [<bf46a8cc>] (init_one_xrpciserialcard+0x1a4/0x300 [xr17v35x])
[ 2377.608561] r9:00000000 r8:c42ba000 r7:00000000 r6:c1205048 r5:c1816000 r4:bf46c0d4
[ 2377.608588] [<bf46a728>] (init_one_xrpciserialcard [xr17v35x]) from [<c07a6b64>] (pci_device_probe+0xb0/0x138)
[ 2377.608604] r10:00000000 r9:bf46c400 r8:bf46c38c r7:00000000 r6:bf46c35c r5:c1816000
[ 2377.608615] r4:c1816070
[ 2377.608634] [<c07a6ab4>] (pci_device_probe) from [<c08441a8>] (really_probe+0x100/0x3c8)
[ 2377.608650] r9:00000018 r8:bf46c38c r7:00000000 r6:c14001d8 r5:c14001d0 r4:c1816070
[ 2377.608665] [<c08440a8>] (really_probe) from [<c084465c>] (driver_probe_device+0x6c/0xc4)
[ 2377.608680] r10:c1205048 r9:bf46c5c0 r8:c37fe3c0 r7:c08448ac r6:bf46c38c r5:bf46c38c
[ 2377.608690] r4:c1816070 r3:00000000
[ 2377.608706] [<c08445f0>] (driver_probe_device) from [<c08448a4>] (device_driver_attach+0x68/0x70)
[ 2377.608716] r5:00000000 r4:c1816070
[ 2377.608731] [<c084483c>] (device_driver_attach) from [<c0844914>] (__driver_attach+0x68/0xdc)
[ 2377.608744] r7:c08448ac r6:c1816070 r5:bf46c38c r4:00000000
[ 2377.608763] [<c08448ac>] (__driver_attach) from [<c0842210>] (bus_for_each_dev+0x84/0xc4)
[ 2377.608776] r7:c08448ac r6:bf46c38c r5:c1205048 r4:c208f734
[ 2377.608793] [<c084218c>] (bus_for_each_dev) from [<c0843b24>] (driver_attach+0x2c/0x30)
[ 2377.608806] r7:00000000 r6:c4914700 r5:c12e7ca4 r4:bf46c38c
[ 2377.608821] [<c0843af8>] (driver_attach) from [<c0843474>] (bus_add_driver+0x1c8/0x1e8)
[ 2377.608836] [<c08432ac>] (bus_add_driver) from [<c0844fe0>] (driver_register+0x84/0x118)
[ 2377.608849] r7:00000000 r6:00000002 r5:bf46b61c r4:bf46c38c
[ 2377.608867] [<c0844f5c>] (driver_register) from [<c07a5de4>] (__pci_register_driver+0x58/0x5c)
[ 2377.608878] r5:bf46b61c r4:00000000
[ 2377.608904] [<c07a5d8c>] (__pci_register_driver) from [<bf08e048>] (serialxr_init+0x48/0x1000 [xr17v35x])
[ 2377.608915] r5:bf08e000 r4:00000000
[ 2377.608942] [<bf08e000>] (serialxr_init [xr17v35x]) from [<c02022a8>] (do_one_initcall+0x50/0x274)
[ 2377.608953] r5:bf08e000 r4:c1205048
[ 2377.608972] [<c0202258>] (do_one_initcall) from [<c02cb710>] (do_init_module+0x70/0x274)
[ 2377.608985] r8:c37fe3c0 r7:c37fe380 r6:00000002 r5:c484bf40 r4:bf46c5c0
[ 2377.609000] [<c02cb6a0>] (do_init_module) from [<c02cdee0>] (load_module+0x244c/0x277c)
[ 2377.609012] r6:00000002 r5:00000002 r4:c4b2bf30
[ 2377.609029] [<c02cba94>] (load_module) from [<c02ce498>] (sys_finit_module+0xc8/0xfc)
[ 2377.609043] r10:0000017b r9:c4b2a000 r8:c0200204 r7:00000003 r6:0002d064 r5:00000000
[ 2377.609053] r4:c1205048
[ 2377.609069] [<c02ce3d0>] (sys_finit_module) from [<c0200040>] (ret_fast_syscall+0x0/0x28)
[ 2377.609082] Exception stack(0xc4b2bfa8 to 0xc4b2bff0)
[ 2377.609096] bfa0: 9bb9fa00 befcd354 00000003 0002d064 00000000 00000005
[ 2377.609111] bfc0: 9bb9fa00 befcd354 0003fce8 0000017b 0115a2b0 00000000 00000002 00000000
[ 2377.609123] bfe0: befcd188 befcd178 00022cb8 b6beaaf0
[ 2377.609137] r7:0000017b r6:0003fce8 r5:befcd354 r4:9bb9fa00
[ 2377.609151] ---[ end trace 414fa36f217afcbd ]---
几个问题：
- 我该如何修复“无法注册串行端口 0，irq 62，类型 2，错误 -28”？
- 如何使用 xr17v354 官方驱动程序？