On Mon, Nov 11, 2019 at 10:23:46PM +0100, Marc Kleine-Budde wrote: > On 11/11/19 7:39 PM, Drew Fustini wrote: > >> I assume you get the 8MHz clock rate from the "ip" output, right? > > > I added printk to output the value of: > > freq = clk_get_rate(clk); > > > > which is from line 1041: > > https://elixir.bootlin.com/linux/latest/source/drivers/net/can/spi/mcp251x.c#L1041 > > > > which shows: > > mcp251x_can_probe: clk_get_rate(clk)=8000000 > > Ok, then let's check if the device tree contains the correct value. Can > you send the output of: > > dtc -I fs -O dts /proc/device-tree > /dts-v1/; / { compatible = "ti,am335x-pocketbeagle", "ti,am335x-bone", "ti,am33xx"; serial-number = "1740GPB21127"; model = "TI AM335x PocketBeagle"; interrupt-parent = <0x1>; #address-cells = <0x1>; #size-cells = <0x1>; mcp2515_clock { compatible = "fixed-clock"; #clock-cells = <0x0>; phandle = <0x21a>; clock-frequency = <0xf42400>; linux,phandle = <0x21a>; }; <snip> mcp2515@1 { compatible = "microchip,mcp2515"; clocks = <0x21a>; mcp251x,irq-gpios = <0x196 0x1c 0x0>; mcp251x,stay-awake = <0x1>; mcp251x,oscillator-frequency = <0xf42400>; status = "okay"; interrupt-parent = <0x196>; interrupts = <0x1c 0x2>; mcp251x,enable-clkout = <0x1>; phandle = <0x21b>; reg = <0x1>; pinctrl-0 = <0x219>; linux,phandle = <0x21b>; spi-max-frequency = <0x989680>; pinctrl-names = "default"; }; 0xf42400 is 16MHz so it does look like device tree has the correct value. Maybe I am not defining the clock correctly? It doesn't appear that the call clk_get_rate(clk) returns the value defined in DT. thanks, drew
