soc/intel/cannonlake: Add chip config to override CPU flex ratio

This patch provides options to override descriptor default CPU flex
ratio from coreboot code. cpu_ratio_override to provide the required CPU
ratio.

Note: Don't override the flex ratio if cpu_ratio is 0.

BUG=b:142264107
TEST=Without override flex_ratio is 0 and verified booting to
OS after overriding with flex_ratio value 5.

Change-Id: Ib01650f52f3d402f669e7e7f5b28a648b86f08ec
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36864
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/soc/intel/cannonlake/chip.h b/src/soc/intel/cannonlake/chip.h
index 17afdd10da..507290f504 100644
--- a/src/soc/intel/cannonlake/chip.h
+++ b/src/soc/intel/cannonlake/chip.h
@@ -424,6 +424,19 @@ struct soc_intel_cannonlake_config {
 	 * Bit 0: MISCCFG_GPDLCGEN
 	 */
 	uint8_t gpio_pm[TOTAL_GPIO_COMM];
+
+	/*
+	 * Override CPU flex ratio value:
+	 * CPU ratio value controls the maximum processor non-turbo ratio.
+	 * Valid Range 0 to 63.
+	 *
+	 * In general descriptor provides option to set default cpu flex ratio.
+	 * Default cpu flex ratio is 0 ensures booting with non-turbo max frequency.
+	 * Thats the reason FSP skips cpu_ratio override if cpu_ratio is 0.
+	 *
+	 * Only override CPU flex ratio if don't want to boot with non-turbo max.
+	 */
+	uint8_t cpu_ratio_override;
 };
 
 typedef struct soc_intel_cannonlake_config config_t;