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
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