Init Clock frequences for accelerators

Hi Tony,

The following series configures the initial frequencies for the required DPLLs and corresponding output divider clocks used by various remoteproc accelerators (DSP, IVAHD) on OMAP4, OMAP5 & DRA7xx/AM57xx SoCs and the GPU on DRA7xx/AM57xx SoCs. All these devices require Adaptive Voltage Scaling (AVS) to be programmed at all OPPs at boot time, which is programmed in the bootloader. Furthermore, DVFS is not supported on these domains implying a one-time OPP clock frequency setup.

IPUs (except for IPU1 on DRA7) being in CORE domain, are clocked by the CORE DPLL and do not require any specific programming. The DPLLs clock rates are configured for OPP_NOM rates which is what the bootloader configures the corresponding voltage domains for by default. The design follows the assigned-clock parents/rates rules for clock providers in the generic clock bindings.

Newer U-boots of 2017.01 and later can also add/update these properties if a different OPP is required. The default is OPP_NOM, and higher OPPs can be supported through configuration of the bootloader. This series sets up the DPLLs for OPP_NOM and be agnostic of the bootloaders w.r.t the clock frequences (like when using older U-Boots).

MPU domain is not affected as it supports DVFS and different OPPs can be supported through the appropriate kernel framework.

I have tested the patches using 4.12-rc4, but they can be applied on the 4.12-rc1 base just fine.

regards
Suman

Subhajit Paul (1):
ARM: dts: dra7xx-clocks: Use DPLL_GPU for GPU clocks

Suman Anna (5):
ARM: dts: omap44xx-clocks: Set IVA DPLL and its output clock rates
ARM: dts: omap54xx-clocks: Set IVA DPLL and its output clock rates
ARM: dts: dra7xx-clocks: Source IPU1 functional clock from CORE DPLL
ARM: dts: dra7xx-clocks: Set DSP DPLL and its output clock rates
ARM: dts: dra7xx-clocks: Set IVA DPLL and its output clock rates

 arch/arm/boot/dts/dra7xx-clocks.dtsi   | 20 ++++++++++++++++++++
 arch/arm/boot/dts/omap44xx-clocks.dtsi |  6 ++++++
 arch/arm/boot/dts/omap54xx-clocks.dtsi |  6 ++++++
 3 files changed, 32 insertions(+)

2.12.0

The IVA DPLL is not an essential DPLL for the functionality of a bootloader and is usually not configured (e.g. older u-boots configure it only if CONFIG_SYS_CLOCKS_ENABLE_ALL is enabled and u-boots newer than 2014.01 do not even have an option), and this results in incorrect operating frequencies when trying to use a DSP or IVAHD, whose root clocks are derived from this DPLL. Use the DT standard properties "assigned-clocks" and "assigned-clock-rates" to set the IVA DPLL clock rate and the rates for its derivative clocks at boot time to properly initialize/lock this DPLL. The DPLL will automatically transition into a low-power stop mode when the associated output clocks are not utilized or gated automatically.

The reset values of the dividers M4 & M5 (functional clocks for DSP and IVAHD respectively) are identical to each other, but are different at each OPP. The reset values also do not match a specific OPP. So, the derived output clocks from the IVA DPLL have to be initialized as well to avoid initializing these divider outputs to incorrect frequencies.

The clock rates are chosen based on the OPP100 values as defined in the OMAP4430 ES2.x Public TRM vAP, section "3.6.3.8.7 DPLL_IVA Preferred Settings". The DPLL locked frequency is 1862.4 MHz (value for DPLL_IVA_X2_CLK), so the dpll_iva_ck clock rate used is half of this value.

---
 arch/arm/boot/dts/omap44xx-clocks.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

index 9573b37fbaa7..9cb205b87835 100644
@@ -357,6 +357,8 @@
 		compatible = "ti,omap4-dpll-clock";
 		clocks = <&sys_clkin_ck>, <&iva_hsd_byp_clk_mux_ck>;
 		reg = <0x01a0>, <0x01a4>, <0x01ac>, <0x01a8>;
+		assigned-clocks = <&dpll_iva_ck>;
+		assigned-clock-rates = <931200000>;
 	};
 
 	dpll_iva_x2_ck: dpll_iva_x2_ck {

@@ -374,6 +376,8 @@
 		reg = <0x01b8>;
 		ti,index-starts-at-one;
 		ti,invert-autoidle-bit;
+		assigned-clocks = <&dpll_iva_m4x2_ck>;
+		assigned-clock-rates = <465600000>;
 	};
 
 	dpll_iva_m5x2_ck: dpll_iva_m5x2_ck at 1bc {

@@ -385,6 +389,8 @@
 		reg = <0x01bc>;
 		ti,index-starts-at-one;
 		ti,invert-autoidle-bit;
+		assigned-clocks = <&dpll_iva_m5x2_ck>;
+		assigned-clock-rates = <266100000>;
 	};
 
 	dpll_mpu_ck: dpll_mpu_ck at 160 {

2.12.0

The IVA DPLL is not an essential DPLL for the functionality of a bootloader and is usually not configured (e.g. older u-boots configure it only if CONFIG_SYS_CLOCKS_ENABLE_ALL is enabled and u-boots newer than 2014.01 do not even have an option), and this results in incorrect operating frequencies when trying to use a DSP or IVAHD, whose root clocks are derived from this DPLL. Use the DT standard properties "assigned-clocks" and "assigned-clock-rates" to set the IVA DPLL clock rate and the rates for its derivative clocks at boot time to properly initialize/lock this DPLL. The DPLL will automatically transition into a low-power stop mode when the associated output clocks are not utilized or gated automatically.

The reset values of the dividers H11 & H12 (functional clocks for DSP and IVAHD respectively) are identical to each other, but are different at each OPP. The reset values also do not match a specific OPP. So, the derived output clocks from the IVA DPLL have to be initialized as well to avoid initializing these divider outputs to incorrect frequencies.

The clock rates are chosen based on the OPP_NOM values as defined in the OMAP5432 SR2.0 Data Manual Book vK, section 5.2.3.5 "DPLL_IVA Preferred Settings". The recommended maximum DPLL locked frequency is 2330 MHz for OPP_NOM (value for DPLL_IVA_X2_CLK), so the dpll_iva_ck clock rate used is half of this value. The value 465.92 MHz is used instead of 465.9 MHz for dpll_iva_h11x2_ck so that proper divider value can be calculated.

---
 arch/arm/boot/dts/omap54xx-clocks.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

index 4899c2359d0a..529193442620 100644
@@ -315,6 +315,8 @@
 		compatible = "ti,omap4-dpll-clock";
 		clocks = <&sys_clkin>, <&dpll_iva_byp_mux>;
 		reg = <0x01a0>, <0x01a4>, <0x01ac>, <0x01a8>;
+		assigned-clocks = <&dpll_iva_ck>;
+		assigned-clock-rates = <1165000000>;
 	};
 
 	dpll_iva_x2_ck: dpll_iva_x2_ck {

@@ -330,6 +332,8 @@
 		ti,max-div = <63>;
 		reg = <0x01b8>;
 		ti,index-starts-at-one;
+		assigned-clocks = <&dpll_iva_h11x2_ck>;
+		assigned-clock-rates = <465920000>;
 	};
 
 	dpll_iva_h12x2_ck: dpll_iva_h12x2_ck at 1bc {

@@ -339,6 +343,8 @@
 		ti,max-div = <63>;
 		reg = <0x01bc>;
 		ti,index-starts-at-one;
+		assigned-clocks = <&dpll_iva_h12x2_ck>;
+		assigned-clock-rates = <388300000>;
 	};
 
 	mpu_dpll_hs_clk_div: mpu_dpll_hs_clk_div {

2.12.0

The IPU1 functional clock is actually the output of a mux clock, ipu1_gfclk_mux. The mux clock is sourced by default from the DPLL_ABE_X2_CLK, and this results in a rather odd clock frequency (361 MHz) for the IPU1 functional clock on platforms where ABE_DPLL is configured properly. Reconfigure the mux clock to be sourced from CORE_IPU_ISS_BOOST_CLK (dpll_core_h22x2_ck), so that both the IPU1 and IPU2 are running from the same clock and clocked at the same nominal frequency of 425 MHz.

This also ensures that IPU1 functional clock is always configured properly and becomes independent of the state of the ABE DPLL on all boards.

---
 arch/arm/boot/dts/dra7xx-clocks.dtsi | 2 ++
 1 file changed, 2 insertions(+)

index 3330738e4c6e..cfaf27215901 100644
@@ -791,6 +791,8 @@
 		clocks = <&dpll_abe_m2x2_ck>, <&dpll_core_h22x2_ck>;
 		ti,bit-shift = <24>;
 		reg = <0x0520>;
+		assigned-clocks = <&ipu1_gfclk_mux>;
+		assigned-clock-parents = <&dpll_core_h22x2_ck>;
 	};
 
 	mcasp1_ahclkr_mux: mcasp1_ahclkr_mux at 550 {

2.12.0

The DSP DPLL is a new DPLL compared to previous OMAP generations and supplies the root clocks for the DSP processors, as well as a mux input source for EVE sub-system (on applicable SoCs). This DPLL is currently not configured by older bootloaders. Use the DT standard properties "assigned-clocks" and "assigned-clock-rates" to set the DSP DPLL clock rate and the rates for its derivative clocks at boot time to properly initialize/lock this DPLL and be independent of the bootloader version. Newer u-boots (from 2017.01 onwards) reuse and can update these properties to choose an appropriate one-time fixed OPP configuration. The DPLL will automatically transition into a low-power stop mode when the associated output clocks are not utilized or gated automatically.

The DSP DPLL provides two output clocks, DSP_GFCLK and EVE_GCLK. The desired rate for DSP_GFCLK is 600 MHz (same as DSP DPLL CLKOUT frequency), and is currently auto set due to the desired M2 divider value being the same as reset value for the locked frequency of 600 MHz. The EVE_GCLK however is required to be 400 MHz, so set the dpll_dsp_m3x2_ck's rate explicitly so that the divider is set properly. The dpll_dsp_m2_ck rate is also set explicitly to not rely on any implicit matching divider reset values to the locked DPLL frequency.

The OPP_NOM clock frequencies are defined in the AM572x SR2.0 Data Sheet vB, section 5.5.2 "Voltage And Core Clock Specifications". The clock rates are chosen based on these OPP_NOM values and defined as per a DRA7xx PLL spec document. The DPLL locked frequency is 1200 MHz, so the dpll_dsp_ck clock rate used is half of this value.

---
 arch/arm/boot/dts/dra7xx-clocks.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

index cfaf27215901..8a82490035d9 100644
@@ -338,6 +338,8 @@
 		compatible = "ti,omap4-dpll-clock";
 		clocks = <&sys_clkin1>, <&dpll_dsp_byp_mux>;
 		reg = <0x0234>, <0x0238>, <0x0240>, <0x023c>;
+		assigned-clocks = <&dpll_dsp_ck>;
+		assigned-clock-rates = <600000000>;
 	};
 
 	dpll_dsp_m2_ck: dpll_dsp_m2_ck at 244 {

@@ -349,6 +351,8 @@
 		reg = <0x0244>;
 		ti,index-starts-at-one;
 		ti,invert-autoidle-bit;
+		assigned-clocks = <&dpll_dsp_m2_ck>;
+		assigned-clock-rates = <600000000>;
 	};
 
 	iva_dpll_hs_clk_div: iva_dpll_hs_clk_div {

@@ -659,6 +663,8 @@
 		reg = <0x0248>;
 		ti,index-starts-at-one;
 		ti,invert-autoidle-bit;
+		assigned-clocks = <&dpll_dsp_m3x2_ck>;
+		assigned-clock-rates = <400000000>;
 	};
 
 	dpll_gmac_x2_ck: dpll_gmac_x2_ck {

2.12.0

The IVA DPLL in DRA7xx provides the output clocks for only the IVAHD subsystem in DRA7xx as compared to previous OMAP generations when it provided the clocks for both DSP and IVAHD subsystems. This DPLL is currently not configured by older bootloaders. Use the DT standard properties "assigned-clocks" and "assigned-clock-rates" to set the IVA DPLL clock rate and the rates for its derivative clocks at boot time to properly initialize/lock this DPLL and be independent of the bootloader version. Newer u-boots (from 2017.01 onwards) reuse and can update these properties to choose an appropriate one-time fixed OPP configuration. The DPLL will automatically transition into a low-power stop mode when the associated output clocks are not utilized or gated automatically.

The reset value of the divider M2 (that supplies the IVA_GFLCK, the functional clock for the IVAHD subsystem) does not match a specific OPP. So, the derived output clock from this IVA DPLL has to be initialized as well to avoid initializing these divider outputs to an incorrect frequencies.

The OPP_NOM clock frequencies are defined in the AM572x SR2.0 Data Sheet vB, section 5.5.2 "Voltage And Core Clock Specifications". The clock rates are chosen based on these OPP_NOM values and defined as per a DRA7xx PLL spec document. The DPLL locked frequency is 2300 MHz, so the dpll_iva_ck clock rate used is half of this value. The value for the divider clock, dpll_iva_m2_ck, has to be set to 388.333334 MHz or more for the divider clk logic to compute the appropriate divider value for OPP_NOM.

---
 arch/arm/boot/dts/dra7xx-clocks.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

index 8a82490035d9..76e2b7478141 100644
@@ -376,6 +376,8 @@
 		compatible = "ti,omap4-dpll-clock";
 		clocks = <&sys_clkin1>, <&dpll_iva_byp_mux>;
 		reg = <0x01a0>, <0x01a4>, <0x01ac>, <0x01a8>;
+		assigned-clocks = <&dpll_iva_ck>;
+		assigned-clock-rates = <1165000000>;
 	};
 
 	dpll_iva_m2_ck: dpll_iva_m2_ck at 1b0 {

@@ -387,6 +389,8 @@
 		reg = <0x01b0>;
 		ti,index-starts-at-one;
 		ti,invert-autoidle-bit;
+		assigned-clocks = <&dpll_iva_m2_ck>;
+		assigned-clock-rates = <388333334>;
 	};
 
 	iva_dclk: iva_dclk {

2.12.0

From: Subhajit Paul <[email protected]>

The GPU has two functional clocks - GPU_CORE_GCLK and GPU_HYD_GCLK. Both of these are mux clocks and are derived from the DPLL_CORE H14 output clock CORE_GPU_CLK by default. These clocks can also be be derived from DPLL_PER or DPLL_GPU.

The GPU DPLL provides the output clocks primarily for the GPU. Configuring the GPU for different OPP clock frequencies is easier to achieve when using the DPLL_GPU rather than the other two DPLLs due to:
1. minimal affect on any other output clocks from these DPLLs
2. may require an impossible post-divider values on existing DPLLs without affecting other clocks.

So, switch the GPU functional clocks to be sourced from GPU DPLL by default. This is done using the DT standard properties "assigned-clocks" and "assigned-clock-parents". Newer u-boots (from 2017.01 onwards) reuse and can update these properties to choose an appropriate one-time fixed OPP configuration as all the required ABB/AVS setup is performed within the bootloader. Note that there is no DVFS supported for any of the non-MPU domains. The DPLL will automatically transition into a low-power stop mode when the associated output clocks are not utilized or gated automatically.

This patch also sets the initial values for the DPLL_GPU outputs. These values are chosen based on the OPP_NOM values defined as per recommendation from design team. The DPLL locked frequency is kept at 1277 MHz, so that the value for the divider clock, dpll_gpu_m2_ck, can be set to 425.67 MHz for OPP_NOM.

---
 arch/arm/boot/dts/dra7xx-clocks.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

index 76e2b7478141..cf229dfabf61 100644
@@ -414,6 +414,8 @@
 		compatible = "ti,omap4-dpll-clock";
 		clocks = <&sys_clkin1>, <&dpll_gpu_byp_mux>;
 		reg = <0x02d8>, <0x02dc>, <0x02e4>, <0x02e0>;
+		assigned-clocks = <&dpll_gpu_ck>;
+		assigned-clock-rates = <1277000000>;
 	};
 
 	dpll_gpu_m2_ck: dpll_gpu_m2_ck at 2e8 {

@@ -425,6 +427,8 @@
 		reg = <0x02e8>;
 		ti,index-starts-at-one;
 		ti,invert-autoidle-bit;
+		assigned-clocks = <&dpll_gpu_m2_ck>;
+		assigned-clock-rates = <425666667>;
 	};
 
 	dpll_core_m2_ck: dpll_core_m2_ck at 130 {

@@ -1760,6 +1764,8 @@
 		clocks = <&dpll_core_h14x2_ck>, <&dpll_per_h14x2_ck>, <&dpll_gpu_m2_ck>;
 		ti,bit-shift = <24>;
 		reg = <0x1220>;
+		assigned-clocks = <&gpu_core_gclk_mux>;
+		assigned-clock-parents = <&dpll_gpu_m2_ck>;
 	};
 
 	gpu_hyd_gclk_mux: gpu_hyd_gclk_mux at 1220 {

@@ -1768,6 +1774,8 @@
 		clocks = <&dpll_core_h14x2_ck>, <&dpll_per_h14x2_ck>, <&dpll_gpu_m2_ck>;
 		ti,bit-shift = <26>;
 		reg = <0x1220>;
+		assigned-clocks = <&gpu_hyd_gclk_mux>;
+		assigned-clock-parents = <&dpll_gpu_m2_ck>;
 	};
 
 	l3instr_ts_gclk_div: l3instr_ts_gclk_div at e50 {

2.12.0

Tero, care to comment or ack this series?

Regards,

Tony

These have been in use in TI releases for quite a while already, and look fine, thus:

(Didn't quite think my ack was needed for them so didn't respond earlier, sorry.)

OK thanks applying all into omap-for-v4.13/dt.

Regards,

Tony