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b3cfac5e37
This patch add support switch for clk-bidirection which located
at GRF, such as SAIx_MCLK_{IN OUT} which share the same pin.
and these config maybe located in many pieces of GRF,
which hard to addressed in one single clk driver. so, we add
this simple helper driver to address this situation.
In order to simplify implement and usage, and also for safety
clk usage (avoid high freq glitch), we set all clk out as disabled
(which means Input default for clk-bidrection) in the pre-stage,
such boot-loader or init by HW default. And then set a safety freq
before enable clk-out, such as "assign-clock-rates" or clk_set_rate
in drivers.
e.g.
1. mclk{out,in}_sai0 define:
mclkin_sai0: mclkin-sai0 {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <12288000>;
clock-output-names = "mclk_sai0_from_io";
};
mclkout_sai0: mclkout-sai0@ff040070 {
compatible = "rockchip,clk-out";
reg = <0 0xff040070 0 0x4>;
clocks = <&cru MCLK_SAI0_OUT2IO>;
#clock-cells = <0>;
clock-output-names = "mclk_sai0_to_io";
rockchip,bit-shift = <4>;
//example with PD if reg access needed
power-domains = <&power RK3562_PD_VO>;
};
Note:
clock-output-names of mclkin_sai0 should equal to strings in drivers. such as:
drivers/clk/rockchip/clk-rk3562.c:
PNAME(clk_sai0_p) = { "clk_sai0_src", "clk_sai0_frac", "xin_osc0_half", "mclk_sai0_from_io" };
2. mclkout_sai0 usage:
&ext_codec {
clocks = <&mclkout_sai0>;
clock-names = "mclk";
assigned-clocks = <&mclkout_sai0>;
assigned-clock-rates = <12288000>;
pinctrl-names = "default";
pinctrl-0 = <&i2s0m0_mclk>;
};
clk_summary on sai0 work:
cat /sys/kernel/debug/clk/clk_summary | egrep "pll|sai0"
clk_sai0_src 1 1 0 1188000000 0 0 50000
clk_sai0_frac 1 1 0 12288000 0 0 50000
clk_sai0 1 1 0 12288000 0 0 50000
mclk_sai0 1 1 0 12288000 0 0 50000
mclk_sai0_out2io 1 1 0 12288000 0 0 50000
mclk_sai0_to_io 1 1 0 12288000 0 0 50000
example with PD if reg access needed:
* PD status when mclk_sai0_to_io on:
cat /sys/kernel/debug/pm_genpd/pm_genpd_summary
domain status children
/device runtime status
----------------------------------------------------------------------
...
vo on
/devices/platform/clocks/ff040070.mclkout-sai0 active
...
* PD status when mclk_sai0_to_io off:
cat /sys/kernel/debug/pm_genpd/pm_genpd_summary
domain status children
/device runtime status
----------------------------------------------------------------------
...
vo off-0
/devices/platform/clocks/ff040070.mclkout-sai0 suspended
...
3. mclkin_sai0 usage:
please override freq of mclkin as the real external clkin, such as:
&mclkin_sai0 {
clock-frequency = <24576000>;
}
&ext_codec {
clocks = <&mclkin_sai0>;
clock-names = "mclk";
assigned-clocks = <&cru CLK_SAI0>;
assigned-clock-parents = <&mclkin_sai0>;
pinctrl-names = "default";
pinctrl-0 = <&i2s0m0_mclk>;
};
clk_summary on sai0 work:
cat /sys/kernel/debug/clk/clk_summary | egrep "pll|sai0"
mclk_sai0_from_io 1 1 0 12288000 0 0 50000
clk_sai0 1 1 0 12288000 0 0 50000
mclk_sai0 1 1 0 12288000 0 0 50000
mclk_sai0_out2io 0 0 0 12288000 0 0 50000
mclk_sai0_to_io 0 0 0 12288000 0 0 50000
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: Ibe8286bb98ea1fc3bc6421c30f6e46fc0b1b0d88
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