Thread (18 messages) 18 messages, 4 authors, 2021-06-06

Re: [PATCH 0/3] Apple M1 clock gate driver

From: Tony Lindgren <tony@atomide.com>
Date: 2021-06-04 07:43:55
Also in: linux-clk, linux-devicetree, lkml

Hi,

* Sven Peter [off-list ref] [210603 12:56]:
Another possibility this made me think of is to instead just use the clocks
property the way it's usually used and simply refer to the controller itself, e.g.

#define APPLE_CLK_UART0  0x270
#define APPLE_CLK_UART_P 0x220
#define APPLE_CLK_SIO    0x1c0

pmgr0: clock-controller@23b700000 {
        compatible = "apple,t8103-gate-clock";
        #clock-cells = <1>;
        reg = <0x2 0x3b700000 0x0 0x4000>;
        clock-indices = <APPLE_CLK_SIO>, <APPLE_CLK_UART_P>, <APPLE_CLK_UART0>;
        clock-output-names = "clock-sio", "clock-uart-", "clock-uart0";
        clocks = <&some_dummy_root_clock>, <&pmgr0 APPLE_CLK_SIO>,
                 <&pmgr0 APPLE_CLK_UART_P>;
};
How about the following where you set up the gate clocks as separate child nodes:

pmgr0: clock-controller@23b700000 {
	compatible = "apple,foo-clock-controller";
	#clock-cells = <1>;
	reg = <0x2 0x3b700000 0x0 0x4000>;

	clk_uart0: clock@270 {
		compatible = "apple,t8103-gate-clock";
		#clock-cells = <0>;
		assigned-clock-parents = <&pmgr0 APPLE_CLK_SIO>,
					 <&pmgr0 APPLE_CLK_UART_P>;
		// ...
	};

};

Keep the clock controller still addressable by offset from base as discussed,
and additionally have the driver parse and set up the child node clocks.

Then I think the consumer driver can just do:

serial0: serial@235200000 {
	// ...
	clocks = <&clk_uart0>, <&clk24>;
	clock-names = "uart", "clk_uart_baud0";
	// ...
};

Regards,

Tony

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help