[PATCH 3/3] arm: mach-k3: am62a: Fixup a53 max cpu frequency by speed-grade

[Aparna Patra]

AM62A SoC has multiple speed grades. Add function to delete
non-relevant CPU frequency nodes, based on the information
retrieved from hardware registers. Fastest grade's maximum
frequency also depends on PMIC voltage,hence to simplify
implementation use the smaller value.

Signed-off-by: Aparna Patra <a-patra at ti.com>
---
 arch/arm/mach-k3/am62ax/am62a7_fdt.c          | 14 +++++++++++
 .../arm/mach-k3/include/mach/am62a_hardware.h | 23 +++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/arch/arm/mach-k3/am62ax/am62a7_fdt.c b/arch/arm/mach-k3/am62ax/am62a7_fdt.c
index 40833ca392..9526c5b255 100644
--- a/arch/arm/mach-k3/am62ax/am62a7_fdt.c
+++ b/arch/arm/mach-k3/am62ax/am62a7_fdt.c
@@ -81,6 +81,19 @@ static void fdt_fixup_thermal_zone_nodes_am62a(void *blob, int maxc)
 	}
 }
 
+static void fdt_fixup_cpu_freq_nodes_am62a(void *blob, int max_freq)
+{
+	if (max_freq >= 1250000000)
+		return;
+	if (max_freq <= 1000000000) {
+		fdt_del_node_path(blob, "/opp-table/opp-1250000000");
+		fdt_del_node_path(blob, "/opp-table/opp-1400000000");
+	}
+	if (max_freq <= 800000000) {
+		fdt_del_node_path(blob, "/opp-table/opp-1000000000");
+	}
+}
+
 int ft_system_setup(void *blob, struct bd_info *bd)
 {
 	fdt_fixup_cores_wdt_nodes_am62a(blob, k3_get_core_nr());
@@ -88,6 +101,7 @@ int ft_system_setup(void *blob, struct bd_info *bd)
 	fdt_fixup_video_codec_nodes_am62a(blob, k3_has_video_codec());
 	fdt_fixup_canfd_nodes_am62a(blob, k3_has_canfd());
 	fdt_fixup_thermal_zone_nodes_am62a(blob, k3_get_max_temp());
+	fdt_fixup_cpu_freq_nodes_am62a(blob, k3_get_a53_max_frequency());
 	fdt_fixup_reserved(blob, "tfa", CONFIG_K3_ATF_LOAD_ADDR, 0x80000);
 	fdt_fixup_reserved(blob, "optee", CONFIG_K3_OPTEE_LOAD_ADDR, 0x1800000);
 
diff --git a/arch/arm/mach-k3/include/mach/am62a_hardware.h b/arch/arm/mach-k3/include/mach/am62a_hardware.h
index 0ec04a72f5..64e4a379fa 100644
--- a/arch/arm/mach-k3/include/mach/am62a_hardware.h
+++ b/arch/arm/mach-k3/include/mach/am62a_hardware.h
@@ -28,6 +28,8 @@
 #define JTAG_DEV_VIDEO_CODEC_SHIFT			14
 #define JTAG_DEV_DSS_MASK			GENMASK(16, 13)
 #define JTAG_DEV_DSS_SHIFT			13
+#define JTAG_DEV_SPEED_MASK			GENMASK(10, 6)
+#define JTAG_DEV_SPEED_SHIFT			6
 #define JTAG_DEV_TEMP_MASK			GENMASK(5, 3)
 #define JTAG_DEV_TEMP_SHIFT			3
 
@@ -144,6 +146,27 @@ static inline int k3_get_max_temp(void)
 		return JTAG_DEV_TEMP_EXTENDED_VALUE;
 }
 
+static inline char k3_get_speed_grade(void)
+{
+	u32 dev_id = readl(CTRLMMR_WKUP_JTAG_DEVICE_ID);
+	u32 speed_grade = (dev_id & JTAG_DEV_SPEED_MASK) >>
+			   JTAG_DEV_SPEED_SHIFT;
+
+	return 'A' - 1 + speed_grade;
+}
+
+static inline int k3_get_a53_max_frequency(void)
+{
+	if (k3_get_speed_grade() <= 'N')
+		return 800000000;
+
+	else if (k3_get_speed_grade() <= 'R')
+		return 1000000000;
+
+	else
+		return 1250000000;
+}
+
 #if defined(CONFIG_SYS_K3_SPL_ATF) && !defined(__ASSEMBLY__)
 
 static const u32 put_device_ids[] = {};
-- 
2.34.1