[PATCH V6 1/2] arm64: dts: freescale: imx8qxp: add cpu opp table

[PATCH V6 1/2] arm64: dts: freescale: imx8qxp: add cpu opp table

[Anson Huang]

Add i.MX8QXP CPU opp table to support cpufreq.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
Changes since V5:
	- add clocks for all secondary CPUs too.
---
 arch/arm64/boot/dts/freescale/imx8qxp.dtsi | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8qxp.dtsi b/arch/arm64/boot/dts/freescale/imx8qxp.dtsi
index aea6812..b5b2dc0 100644
--- a/arch/arm64/boot/dts/freescale/imx8qxp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8qxp.dtsi
@@ -34,6 +34,9 @@
 			reg = <0x0 0x0>;
 			enable-method = "psci";
 			next-level-cache = <&A35_L2>;
+			clocks = <&clk IMX_A35_CLK>;
+			operating-points-v2 = <&a35_0_opp_table>;
+			#cooling-cells = <2>;
 		};
 
 		A35_1: cpu@1 {
@@ -42,6 +45,9 @@
 			reg = <0x0 0x1>;
 			enable-method = "psci";
 			next-level-cache = <&A35_L2>;
+			clocks = <&clk IMX_A35_CLK>;
+			operating-points-v2 = <&a35_0_opp_table>;
+			#cooling-cells = <2>;
 		};
 
 		A35_2: cpu@2 {
@@ -50,6 +56,9 @@
 			reg = <0x0 0x2>;
 			enable-method = "psci";
 			next-level-cache = <&A35_L2>;
+			clocks = <&clk IMX_A35_CLK>;
+			operating-points-v2 = <&a35_0_opp_table>;
+			#cooling-cells = <2>;
 		};
 
 		A35_3: cpu@3 {
@@ -58,6 +67,9 @@
 			reg = <0x0 0x3>;
 			enable-method = "psci";
 			next-level-cache = <&A35_L2>;
+			clocks = <&clk IMX_A35_CLK>;
+			operating-points-v2 = <&a35_0_opp_table>;
+			#cooling-cells = <2>;
 		};
 
 		A35_L2: l2-cache0 {
@@ -65,6 +77,24 @@
 		};
 	};
 
+	a35_0_opp_table: opp-table {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp-900000000 {
+			opp-hz = /bits/ 64 <900000000>;
+			opp-microvolt = <1000000>;
+			clock-latency-ns = <150000>;
+		};
+
+		opp-1200000000 {
+			opp-hz = /bits/ 64 <1200000000>;
+			opp-microvolt = <1100000>;
+			clock-latency-ns = <150000>;
+			opp-suspend;
+		};
+	};
+
 	gic: interrupt-controller@51a00000 {
 		compatible = "arm,gic-v3";
 		reg = <0x0 0x51a00000 0 0x10000>, /* GIC Dist */
-- 
2.7.4

[PATCH V6 2/2] clk: imx: scu: add cpu frequency scaling support

[Anson Huang]

On NXP's i.MX SoCs with system controller inside, CPU frequency
scaling can ONLY be done by system controller firmware, and it
can ONLY be requested from secure mode, so Linux kernel has to
call ARM SMC to trap to ARM-Trusted-Firmware to request system
controller firmware to do CPU frequency scaling.

This patch adds i.MX system controller CPU frequency scaling support,
it reuses cpufreq-dt driver and implement the CPU frequency scaling
inside SCU clock driver.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
No changes since V5.
---
 drivers/clk/imx/clk-scu.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
index 7ccf7ed..c234a6e 100644
--- a/drivers/clk/imx/clk-scu.c
+++ b/drivers/clk/imx/clk-scu.c
@@ -4,12 +4,17 @@
  *   Dong Aisheng <aisheng.dong@nxp.com>
  */
 
+#include <dt-bindings/firmware/imx/rsrc.h>
+#include <linux/arm-smccc.h>
 #include <linux/clk-provider.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 
 #include "clk-scu.h"
 
+#define IMX_SIP_CPUFREQ			0xC2000001
+#define IMX_SIP_SET_CPUFREQ		0x00
+
 static struct imx_sc_ipc *ccm_ipc_handle;
 
 /*
@@ -145,6 +150,23 @@ static long clk_scu_round_rate(struct clk_hw *hw, unsigned long rate,
 	return rate;
 }
 
+static int clk_scu_atf_set_cpu_rate(struct clk_hw *hw, unsigned long rate,
+				    unsigned long parent_rate)
+{
+	struct clk_scu *clk = to_clk_scu(hw);
+	struct arm_smccc_res res;
+	unsigned long cluster_id;
+
+	if (clk->rsrc_id == IMX_SC_R_A35)
+		cluster_id = 0;
+
+	/* CPU frequency scaling can ONLY be done by ARM-Trusted-Firmware */
+	arm_smccc_smc(IMX_SIP_CPUFREQ, IMX_SIP_SET_CPUFREQ,
+		      cluster_id, rate, 0, 0, 0, 0, &res);
+
+	return 0;
+}
+
 /*
  * clk_scu_set_rate - Set rate for a SCU clock
  * @hw: clock to change rate for
@@ -232,6 +254,14 @@ static const struct clk_ops clk_scu_ops = {
 	.unprepare = clk_scu_unprepare,
 };
 
+static const struct clk_ops clk_scu_cpu_ops = {
+	.recalc_rate = clk_scu_recalc_rate,
+	.round_rate = clk_scu_round_rate,
+	.set_rate = clk_scu_atf_set_cpu_rate,
+	.prepare = clk_scu_prepare,
+	.unprepare = clk_scu_unprepare,
+};
+
 struct clk_hw *imx_clk_scu(const char *name, u32 rsrc_id, u8 clk_type)
 {
 	struct clk_init_data init;
@@ -247,7 +277,10 @@ struct clk_hw *imx_clk_scu(const char *name, u32 rsrc_id, u8 clk_type)
 	clk->clk_type = clk_type;
 
 	init.name = name;
-	init.ops = &clk_scu_ops;
+	if (rsrc_id == IMX_SC_R_A35)
+		init.ops = &clk_scu_cpu_ops;
+	else
+		init.ops = &clk_scu_ops;
 	init.num_parents = 0;
 	/*
 	 * Note on MX8, the clocks are tightly coupled with power domain
-- 
2.7.4

Re: [PATCH V6 1/2] arm64: dts: freescale: imx8qxp: add cpu opp table

[Viresh Kumar]

On 14-02-19, 09:55, Anson Huang wrote:
> Add i.MX8QXP CPU opp table to support cpufreq.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> Changes since V5:
> 	- add clocks for all secondary CPUs too.
> ---
>  arch/arm64/boot/dts/freescale/imx8qxp.dtsi | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh

Re: [PATCH V6 2/2] clk: imx: scu: add cpu frequency scaling support

[Stephen Boyd]

Quoting Anson Huang (2019-02-14 01:55:57)
> On NXP's i.MX SoCs with system controller inside, CPU frequency
> scaling can ONLY be done by system controller firmware, and it
> can ONLY be requested from secure mode, so Linux kernel has to
> call ARM SMC to trap to ARM-Trusted-Firmware to request system
> controller firmware to do CPU frequency scaling.
> 
> This patch adds i.MX system controller CPU frequency scaling support,
> it reuses cpufreq-dt driver and implement the CPU frequency scaling
> inside SCU clock driver.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---

Acked-by: Stephen Boyd <sboyd@kernel.org>