mirror of https://gitee.com/openkylin/linux.git
109 lines
2.8 KiB
Plaintext
109 lines
2.8 KiB
Plaintext
Device Tree Clock bindings for the Zynq 7000 EPP
|
|
|
|
The Zynq EPP has several different clk providers, each with there own bindings.
|
|
The purpose of this document is to document their usage.
|
|
|
|
See clock_bindings.txt for more information on the generic clock bindings.
|
|
See Chapter 25 of Zynq TRM for more information about Zynq clocks.
|
|
|
|
== Clock Controller ==
|
|
The clock controller is a logical abstraction of Zynq's clock tree. It reads
|
|
required input clock frequencies from the devicetree and acts as clock provider
|
|
for all clock consumers of PS clocks.
|
|
|
|
Required properties:
|
|
- #clock-cells : Must be 1
|
|
- compatible : "xlnx,ps7-clkc"
|
|
- ps-clk-frequency : Frequency of the oscillator providing ps_clk in HZ
|
|
(usually 33 MHz oscillators are used for Zynq platforms)
|
|
- clock-output-names : List of strings used to name the clock outputs. Shall be
|
|
a list of the outputs given below.
|
|
|
|
Optional properties:
|
|
- clocks : as described in the clock bindings
|
|
- clock-names : as described in the clock bindings
|
|
- fclk-enable : Bit mask to enable FCLKs statically at boot time.
|
|
Bit [0..3] correspond to FCLK0..FCLK3. The corresponding
|
|
FCLK will only be enabled if it is actually running at
|
|
boot time.
|
|
|
|
Clock inputs:
|
|
The following strings are optional parameters to the 'clock-names' property in
|
|
order to provide an optional (E)MIO clock source.
|
|
- swdt_ext_clk
|
|
- gem0_emio_clk
|
|
- gem1_emio_clk
|
|
- mio_clk_XX # with XX = 00..53
|
|
...
|
|
|
|
Clock outputs:
|
|
0: armpll
|
|
1: ddrpll
|
|
2: iopll
|
|
3: cpu_6or4x
|
|
4: cpu_3or2x
|
|
5: cpu_2x
|
|
6: cpu_1x
|
|
7: ddr2x
|
|
8: ddr3x
|
|
9: dci
|
|
10: lqspi
|
|
11: smc
|
|
12: pcap
|
|
13: gem0
|
|
14: gem1
|
|
15: fclk0
|
|
16: fclk1
|
|
17: fclk2
|
|
18: fclk3
|
|
19: can0
|
|
20: can1
|
|
21: sdio0
|
|
22: sdio1
|
|
23: uart0
|
|
24: uart1
|
|
25: spi0
|
|
26: spi1
|
|
27: dma
|
|
28: usb0_aper
|
|
29: usb1_aper
|
|
30: gem0_aper
|
|
31: gem1_aper
|
|
32: sdio0_aper
|
|
33: sdio1_aper
|
|
34: spi0_aper
|
|
35: spi1_aper
|
|
36: can0_aper
|
|
37: can1_aper
|
|
38: i2c0_aper
|
|
39: i2c1_aper
|
|
40: uart0_aper
|
|
41: uart1_aper
|
|
42: gpio_aper
|
|
43: lqspi_aper
|
|
44: smc_aper
|
|
45: swdt
|
|
46: dbg_trc
|
|
47: dbg_apb
|
|
|
|
Example:
|
|
clkc: clkc {
|
|
#clock-cells = <1>;
|
|
compatible = "xlnx,ps7-clkc";
|
|
ps-clk-frequency = <33333333>;
|
|
clock-output-names = "armpll", "ddrpll", "iopll", "cpu_6or4x",
|
|
"cpu_3or2x", "cpu_2x", "cpu_1x", "ddr2x", "ddr3x",
|
|
"dci", "lqspi", "smc", "pcap", "gem0", "gem1",
|
|
"fclk0", "fclk1", "fclk2", "fclk3", "can0", "can1",
|
|
"sdio0", "sdio1", "uart0", "uart1", "spi0", "spi1",
|
|
"dma", "usb0_aper", "usb1_aper", "gem0_aper",
|
|
"gem1_aper", "sdio0_aper", "sdio1_aper",
|
|
"spi0_aper", "spi1_aper", "can0_aper", "can1_aper",
|
|
"i2c0_aper", "i2c1_aper", "uart0_aper", "uart1_aper",
|
|
"gpio_aper", "lqspi_aper", "smc_aper", "swdt",
|
|
"dbg_trc", "dbg_apb";
|
|
# optional props
|
|
clocks = <&clkc 16>, <&clk_foo>;
|
|
clock-names = "gem1_emio_clk", "can_mio_clk_23";
|
|
};
|