I'm trying to use native (real hardware) interfaces like can0 in R-CAR
E2 based board (RTP0RC7794SEB00011S - ALT board). I am able to configure
the CAN interfaces (can0 and can1). While testing, CAN driver seems to
be able to send the CAN packets but not able to receive CAN packets from
bus. Please help me to fix this issue.
I had made the following changes.
1) Built the AGL kernel (3.10.31-ltsi) with CAN (SOCKET CAN) support by
changing the configuration using menuconfig utility.
a) CONFIG_CAN=y
b) CONFIG_CAN_RAW=y
c) CONFIG_CAN_BCM=y
d) CONFIG_CAN_GW=y
e) CONFIG_CAN_VCAN=y
f) CONFIG_CAN_SLCAN=y
g) CONFIG_CAN_DEV=y
h) CONFIG_CAN_CALC_BITTIMING=y
i) CONFIG_CAN_RCAR=y
2) Added can0 and can1 pins details at the end of 'pfc' block in
r8a7794-silk.dts file. Also added can0 and can1 block in the same file.
### Adding CAN pin details in pfc ###
&pfc {
pinctrl-0 = <&du_pins &du0_pins &du1_pins &usb0_pins &usb1_pins
&sound_pins &sound_clk_pins
&vin0_pins &can0_pins &can1_pins>;
pinctrl-names = "default";
...
can0_pins: can0 {
renesas,groups = "can0_data_b";
renesas,function = "can0";
};
can1_pins: can1 {
renesas,groups = "can1_data_b";
renesas,function = "can1";
};
};
### Adding can0 and can1 block ###
&can0 {
pinctrl-0 = <&can0_pins>;
pinctrl-names = "default";
renesas,can-clock-select = <0x0>;
status = "okay";
};
&can1 {
pinctrl-0 = <&can1_pins>;
pinctrl-names = "default";
renesas,can-clock-select = <0x0>;
status = "okay";
};
3) Modified the r8a7794.dtsi file and add can0 and can1 interface
support. Also modified 'mstp9_clks' section to add can0 and can1 clock.
### Adding can0 and can1 interface support ###
can0: can@e6e80000 {
compatible = "renesas,can-r8a7794";
reg = <0 0xe6e80000 0 0x1000>;
interrupts = <0 186 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&mstp9_clks R8A7794_CLK_RCAN0>;
clock-names = "clkp1", "clkp2", "can_clk";
status = "okay";
};
can1: can@e6e88000 {
compatible = "renesas,can-r8a7794";
reg = <0 0xe6e88000 0 0x1000>;
interrupts = <0 187 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&mstp9_clks R8A7794_CLK_RCAN1>;
clock-names = "clkp1", "clkp2", "can_clk";
status = "okay";
};
### Adding CAN Clock settings in mstp9_clks ###
mstp9_clks: mstp9_clks@e6150994 {
compatible = "renesas,r8a7794-mstp-clocks",
"renesas,cpg-mstp-clocks";
reg = <0 0xe6150994 0 4>, <0 0xe61509a4 0 4>;
clocks = <&cp_clk>, <&cp_clk>, <&cp_clk>,
<&cp_clk>, <&cp_clk>, <&cp_clk>,
<&cp_clk>, <&p_clk>, <&p_clk>,
<&cpg_clocks R8A7794_CLK_QSPI>, <&hp_clk>,
<&hp_clk>, <&hp_clk>, <&hp_clk>,
<&hp_clk>, <&hp_clk>;
#clock-cells = <1>;
renesas,clock-indices = <
R8A7794_CLK_GPIO6 R8A7794_CLK_GPIO5
R8A7794_CLK_GPIO4
R8A7794_CLK_GPIO3 R8A7794_CLK_GPIO2
R8A7794_CLK_GPIO1
R8A7794_CLK_GPIO0 R8A7794_CLK_RCAN1
R8A7794_CLK_RCAN0
R8A7794_CLK_QSPI_MOD R8A7794_CLK_I2C5
R8A7794_CLK_I2C4
R8A7794_CLK_I2C3 R8A7794_CLK_I2C2 R8A7794_CLK_I2C1
R8A7794_CLK_I2C0
>;
clock-output-names =
"gpio7", "gpio6", "gpio5", "gpio4", "gpio3",
"gpio2", "gpio1", "gpio0",
"rcan1", "rcan0","qspi_mod", "i2c5", "i2c4",
"i2c3", "i2c2",
"i2c1", "i2c0";
};
4) Added 'R8A7794_CLK_RCAN1' and 'R8A7794_CLK_RCAN0' clocks macros in
'includes/dt-bindings/clock/r8a7794-clock.h' file
/* MSTP9 */
...
#define R8A7794_CLK_RCAN1 15
#define R8A7794_CLK_RCAN0 16
...
5) Added R-CAR E2 in compatibility list in 'drivers/net/can/rcar_can.c'
file
static const struct of_device_id rcar_can_of_table[] __maybe_unused = {
...
{ .compatible = "renesas,can-r8a7794" },
{ }
};
6) Cross-compiled the iproute2 and can-utils utilities for testing.
###################################################################################################
After booting 'dmesg | grep -i can' shows
pinmux core: sh-pfc does not support function can0
sh-pfc e6060000.pfc: invalid function can0 in map table
pinmux core: sh-pfc does not support function can1
sh-pfc e6060000.pfc: invalid function can1 in map table
vcan: Virtual CAN interface driver
slcan: serial line CAN interface driver
slcan: 10 dynamic interface channels.
CAN device driver interface
pinmux core: sh-pfc does not support function can0
sh-pfc e6060000.pfc: invalid function can0 in map table
rcar_can e6e80000.can: device registered (reg_base=e78d4000, irq=218)
pinmux core: sh-pfc does not support function can1
sh-pfc e6060000.pfc: invalid function can1 in map table
rcar_can e6e88000.can: device registered (reg_base=e78d6000, irq=219)
can: controller area network core (rev 20120528 abi 9)
can: raw protocol (rev 20120528)
can: broadcast manager protocol (rev 20120528 t)
can: netlink gateway (rev 20130117) max_hops=1
After running the command './ip link set can0 type can bitrate 125000 &&
ifconfig can0 up' , then interface 'can0' can be listed with ifconfig
command
ifconfig
can0 Link encap:UNSPEC HWaddr
00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
UP RUNNING NOARP MTU:16 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:10
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:218
cat /proc/net/can/version shows
rev 20120528 abi 9
cat /proc/net/can/stats initially shows
0 transmitted frames (TXF)
0 received frames (RXF)
0 matched frames (RXMF)
0 % total match ratio (RXMR)
0 frames/s total tx rate (TXR)
0 frames/s total rx rate (RXR)
0 % current match ratio (CRXMR)
0 frames/s current tx rate (CTXR)
0 frames/s current rx rate (CRXR)
0 % max match ratio (MRXMR)
0 frames/s max tx rate (MTXR)
0 frames/s max rx rate (MRXR)
0 current receive list entries (CRCV)
0 maximum receive list entries (MRCV)
After sending packet with './cansend can0 5A1#11.22', then 'cat
/proc/net/can/stats' shows
1 transmitted frames (TXF)
0 received frames (RXF)
0 matched frames (RXMF)
0 % total match ratio (RXMR)
0 frames/s total tx rate (TXR)
0 frames/s total rx rate (RXR)
0 % current match ratio (CRXMR)
0 frames/s current tx rate (CTXR)
0 frames/s current rx rate (CRXR)
0 % max match ratio (MRXMR)
1 frames/s max tx rate (MTXR)
0 frames/s max rx rate (MRXR)
0 current receive list entries (CRCV)
0 maximum receive list entries (MRCV)
Then I ran ./candump can0 & (in background) and then tried to send
packet to can0 using ./cansend can0 5A1#11.22 command, but unable to
receive the packets. 'cat /proc/net/can/stats' shows
2 transmitted frames (TXF)
0 received frames (RXF)
0 matched frames (RXMF)
0 % total match ratio (RXMR)
0 frames/s total tx rate (TXR)
0 frames/s total rx rate (RXR)
0 % current match ratio (CRXMR)
0 frames/s current tx rate (CTXR)
0 frames/s current rx rate (CRXR)
0 % max match ratio (MRXMR)
1 frames/s max tx rate (MTXR)
0 frames/s max rx rate (MRXR)
1 current receive list entries (CRCV)
1 maximum receive list entries (MRCV)
I put printk messages in the start of all the functions written in
'rcar_can.c' for debugging purpose, only the following functions are
called during the operations.
a) rcar_can_probe --> <called @ boot time >
b) rcar_can_get_berr_counter --> <called several times >
c) rcar_can_open --> <called @ifconfig canx up>
d) rcar_can_start --> <called @ifconfig canx up>
e) rcar_can_set_bittiming --> <called @ifconfig canx up>
f) rcar_can_start_xmit --> <called @ cansend >
My questions are
1) I couldn't see r8a7794 in the CAN compatibility list. R-CAR CAN
driver is able to supports R-CAR E2 CAN interface ?
2) Is there any additional modifications are needed in any of the driver
source like pfc for supporting receive functionality (Rx)?
3) Is there any errors in the modifications I have done ? Showing the
following warnings/error while booting
a) pinmux core: sh-pfc does not support function can0
b) sh-pfc e6060000.pfc: invalid function can0 in map table
4) Is there any working patches available for CAN support in R-CAR E2
based board (Alt/Silk) ?
5) Is there any external hardware devices are required for testing ?
6) Is there any hardware settings (like jumper) need to be done in board ?
Regards,
RKP
