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OpenCloudOS-Kernel/Documentation/devicetree/bindings/clock/ti-clkctrl.txt

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Documentation: dt-bindings: Add binding documentation for TI clkctrl clocks Texas Instruments omap variant SoCs starting with omap4 have a clkctrl clock controller instance for each interconnect target module. The clkctrl controls functional and interface clocks for the module. The clkctrl clocks are currently handled by arch/arm/mach-omap2 hwmod code. With this binding and a related clock device driver we can start moving the clkctrl clock handling to live in drivers/clk/ti. Note that this binding allows keeping the clockdomain related parts out of drivers/clock. The CLKCTCTRL and DYNAMICDEP registers can be handled by a separate driver in drivers/soc/ti and genpd. If the clockdomain driver needs to know it's clocks, we can just set the the clkctrl device instances to be children of the related clockdomain device. Each clkctrl clock can have multiple optional gate clocks, and multiple optional mux clocks. To represent this in device tree, it seems that it is best done using four clock cells #clock-cells = <2> property. The reasons for using #clock-cells = <2> are: 1. We need to specify the clkctrl offset from the instance base. Otherwise we end up with a large number of device tree nodes that need to be patched when new clocks are discovered in a clkctrl clock with minor hardware revision changes for example 2. On omap5 CM_L3INIT_USB_HOST_HS_CLKCTRL has ten OPTFCLKEN bits. So we need to use a separate cell for optional gate clocks to avoid address space conflicts There is probably no need to list input clocks for each clkctrl clock instance in the binding. If we want to add them, the standard clocks binding can be used for that. For hardware reference, see omap4430 TRM "Table 3-1312. L4PER_CM2 Registers Mapping Summary" for example. It shows one instance of a clkctrl clock controller with multiple clkctrl registers. Cc: Paul Walmsley <paul@pwsan.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2017-01-24 06:17:02 +08:00
Texas Instruments clkctrl clock binding
Texas Instruments SoCs can have a clkctrl clock controller for each
interconnect target module. The clkctrl clock controller manages functional
and interface clocks for each module. Each clkctrl controller can also
gate one or more optional functional clocks for a module, and can have one
or more clock muxes. There is a clkctrl clock controller typically for each
interconnect target module on omap4 and later variants.
The clock consumers can specify the index of the clkctrl clock using
the hardware offset from the clkctrl instance register space. The optional
clocks can be specified by clkctrl hardware offset and the index of the
optional clock.
For more information, please see the Linux clock framework binding at
Documentation/devicetree/bindings/clock/clock-bindings.txt.
Required properties :
clk: ti: clkctrl: Fix hidden dependency to node name We currently have a hidden dependency to the device tree node name for the clkctrl clocks. Instead of using standard node name like "clock", we must use "l4-per-clkctrl" type naming so the clock driver can find the associated clock domain. Further, if "clk" is specified for a clock node name, the driver sets TI_CLK_CLKCTRL_COMPAT flag that uses different logic for the clock name based on the parent node name for the all the clkctrl clocks for the SoC. If the clock node naming dependency is not understood, the related clockdomain is not found, or a wrong one can get used if a clock manager has multiple clock domains. As each clkctrl instance represents a single clock domain, let's allow using domain specific compatible names to specify the clock domain. This simplifies things and removes the hidden dependency to the node name. And then later on, after the node names have been standardized, we can drop the related code for parsing the node names. Let's also update the binding to use standard "clock" node naming instead of "clk" and add the missing description for reg. Cc: devicetree@vger.kernel.org Cc: Rob Herring <robh+dt@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2019-12-11 01:21:04 +08:00
- compatible : shall be "ti,clkctrl" or a clock domain specific name:
"ti,clkctrl-l4-cfg"
"ti,clkctrl-l4-per"
"ti,clkctrl-l4-secure"
"ti,clkctrl-l4-wkup"
Documentation: dt-bindings: Add binding documentation for TI clkctrl clocks Texas Instruments omap variant SoCs starting with omap4 have a clkctrl clock controller instance for each interconnect target module. The clkctrl controls functional and interface clocks for the module. The clkctrl clocks are currently handled by arch/arm/mach-omap2 hwmod code. With this binding and a related clock device driver we can start moving the clkctrl clock handling to live in drivers/clk/ti. Note that this binding allows keeping the clockdomain related parts out of drivers/clock. The CLKCTCTRL and DYNAMICDEP registers can be handled by a separate driver in drivers/soc/ti and genpd. If the clockdomain driver needs to know it's clocks, we can just set the the clkctrl device instances to be children of the related clockdomain device. Each clkctrl clock can have multiple optional gate clocks, and multiple optional mux clocks. To represent this in device tree, it seems that it is best done using four clock cells #clock-cells = <2> property. The reasons for using #clock-cells = <2> are: 1. We need to specify the clkctrl offset from the instance base. Otherwise we end up with a large number of device tree nodes that need to be patched when new clocks are discovered in a clkctrl clock with minor hardware revision changes for example 2. On omap5 CM_L3INIT_USB_HOST_HS_CLKCTRL has ten OPTFCLKEN bits. So we need to use a separate cell for optional gate clocks to avoid address space conflicts There is probably no need to list input clocks for each clkctrl clock instance in the binding. If we want to add them, the standard clocks binding can be used for that. For hardware reference, see omap4430 TRM "Table 3-1312. L4PER_CM2 Registers Mapping Summary" for example. It shows one instance of a clkctrl clock controller with multiple clkctrl registers. Cc: Paul Walmsley <paul@pwsan.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2017-01-24 06:17:02 +08:00
- #clock-cells : shall contain 2 with the first entry being the instance
offset from the clock domain base and the second being the
clock index
clk: ti: clkctrl: Fix hidden dependency to node name We currently have a hidden dependency to the device tree node name for the clkctrl clocks. Instead of using standard node name like "clock", we must use "l4-per-clkctrl" type naming so the clock driver can find the associated clock domain. Further, if "clk" is specified for a clock node name, the driver sets TI_CLK_CLKCTRL_COMPAT flag that uses different logic for the clock name based on the parent node name for the all the clkctrl clocks for the SoC. If the clock node naming dependency is not understood, the related clockdomain is not found, or a wrong one can get used if a clock manager has multiple clock domains. As each clkctrl instance represents a single clock domain, let's allow using domain specific compatible names to specify the clock domain. This simplifies things and removes the hidden dependency to the node name. And then later on, after the node names have been standardized, we can drop the related code for parsing the node names. Let's also update the binding to use standard "clock" node naming instead of "clk" and add the missing description for reg. Cc: devicetree@vger.kernel.org Cc: Rob Herring <robh+dt@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2019-12-11 01:21:04 +08:00
- reg : clock registers
Documentation: dt-bindings: Add binding documentation for TI clkctrl clocks Texas Instruments omap variant SoCs starting with omap4 have a clkctrl clock controller instance for each interconnect target module. The clkctrl controls functional and interface clocks for the module. The clkctrl clocks are currently handled by arch/arm/mach-omap2 hwmod code. With this binding and a related clock device driver we can start moving the clkctrl clock handling to live in drivers/clk/ti. Note that this binding allows keeping the clockdomain related parts out of drivers/clock. The CLKCTCTRL and DYNAMICDEP registers can be handled by a separate driver in drivers/soc/ti and genpd. If the clockdomain driver needs to know it's clocks, we can just set the the clkctrl device instances to be children of the related clockdomain device. Each clkctrl clock can have multiple optional gate clocks, and multiple optional mux clocks. To represent this in device tree, it seems that it is best done using four clock cells #clock-cells = <2> property. The reasons for using #clock-cells = <2> are: 1. We need to specify the clkctrl offset from the instance base. Otherwise we end up with a large number of device tree nodes that need to be patched when new clocks are discovered in a clkctrl clock with minor hardware revision changes for example 2. On omap5 CM_L3INIT_USB_HOST_HS_CLKCTRL has ten OPTFCLKEN bits. So we need to use a separate cell for optional gate clocks to avoid address space conflicts There is probably no need to list input clocks for each clkctrl clock instance in the binding. If we want to add them, the standard clocks binding can be used for that. For hardware reference, see omap4430 TRM "Table 3-1312. L4PER_CM2 Registers Mapping Summary" for example. It shows one instance of a clkctrl clock controller with multiple clkctrl registers. Cc: Paul Walmsley <paul@pwsan.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2017-01-24 06:17:02 +08:00
Example: Clock controller node on omap 4430:
&cm2 {
l4per: cm@1400 {
cm_l4per@0 {
clk: ti: clkctrl: Fix hidden dependency to node name We currently have a hidden dependency to the device tree node name for the clkctrl clocks. Instead of using standard node name like "clock", we must use "l4-per-clkctrl" type naming so the clock driver can find the associated clock domain. Further, if "clk" is specified for a clock node name, the driver sets TI_CLK_CLKCTRL_COMPAT flag that uses different logic for the clock name based on the parent node name for the all the clkctrl clocks for the SoC. If the clock node naming dependency is not understood, the related clockdomain is not found, or a wrong one can get used if a clock manager has multiple clock domains. As each clkctrl instance represents a single clock domain, let's allow using domain specific compatible names to specify the clock domain. This simplifies things and removes the hidden dependency to the node name. And then later on, after the node names have been standardized, we can drop the related code for parsing the node names. Let's also update the binding to use standard "clock" node naming instead of "clk" and add the missing description for reg. Cc: devicetree@vger.kernel.org Cc: Rob Herring <robh+dt@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2019-12-11 01:21:04 +08:00
cm_l4per_clkctrl: clock@20 {
compatible = "ti,clkctrl-l4-per", "ti,clkctrl";
Documentation: dt-bindings: Add binding documentation for TI clkctrl clocks Texas Instruments omap variant SoCs starting with omap4 have a clkctrl clock controller instance for each interconnect target module. The clkctrl controls functional and interface clocks for the module. The clkctrl clocks are currently handled by arch/arm/mach-omap2 hwmod code. With this binding and a related clock device driver we can start moving the clkctrl clock handling to live in drivers/clk/ti. Note that this binding allows keeping the clockdomain related parts out of drivers/clock. The CLKCTCTRL and DYNAMICDEP registers can be handled by a separate driver in drivers/soc/ti and genpd. If the clockdomain driver needs to know it's clocks, we can just set the the clkctrl device instances to be children of the related clockdomain device. Each clkctrl clock can have multiple optional gate clocks, and multiple optional mux clocks. To represent this in device tree, it seems that it is best done using four clock cells #clock-cells = <2> property. The reasons for using #clock-cells = <2> are: 1. We need to specify the clkctrl offset from the instance base. Otherwise we end up with a large number of device tree nodes that need to be patched when new clocks are discovered in a clkctrl clock with minor hardware revision changes for example 2. On omap5 CM_L3INIT_USB_HOST_HS_CLKCTRL has ten OPTFCLKEN bits. So we need to use a separate cell for optional gate clocks to avoid address space conflicts There is probably no need to list input clocks for each clkctrl clock instance in the binding. If we want to add them, the standard clocks binding can be used for that. For hardware reference, see omap4430 TRM "Table 3-1312. L4PER_CM2 Registers Mapping Summary" for example. It shows one instance of a clkctrl clock controller with multiple clkctrl registers. Cc: Paul Walmsley <paul@pwsan.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2017-01-24 06:17:02 +08:00
reg = <0x20 0x1b0>;
#clock-cells = <2>;
};
};
};
};
Example: Preprocessor helper macros in dt-bindings/clock/ti-clkctrl.h
#define OMAP4_CLKCTRL_OFFSET 0x20
#define OMAP4_CLKCTRL_INDEX(offset) ((offset) - OMAP4_CLKCTRL_OFFSET)
#define MODULEMODE_HWCTRL 1
#define MODULEMODE_SWCTRL 2
#define OMAP4_GPTIMER10_CLKTRL OMAP4_CLKCTRL_INDEX(0x28)
#define OMAP4_GPTIMER11_CLKTRL OMAP4_CLKCTRL_INDEX(0x30)
#define OMAP4_GPTIMER2_CLKTRL OMAP4_CLKCTRL_INDEX(0x38)
...
#define OMAP4_GPIO2_CLKCTRL OMAP_CLKCTRL_INDEX(0x60)
Example: Clock consumer node for GPIO2:
&gpio2 {
clocks = <&cm_l4per_clkctrl OMAP4_GPIO2_CLKCTRL 0
&cm_l4per_clkctrl OMAP4_GPIO2_CLKCTRL 8>;
};