nb/intel/sandybridge: Rewrite get_FRQ
The code is just clamping the frequency index to a valid range. Do it with a helper function. Also, add a CPUID check, as Sandy Bridge will eventually use this code. Change-Id: I4c7aa5f7615c6edb1ab62fb004abb126df9d284b Signed-off-by: Angel Pons <th3fanbus@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/39787 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
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@ -0,0 +1,22 @@
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/* SPDX-License-Identifier: GPL-2.0-only */
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#ifndef COMMONLIB_CLAMP_H
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#define COMMONLIB_CLAMP_H
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#include <stdint.h>
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/*
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* Clamp a value, so that it is between a lower and an upper bound.
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*/
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static inline u32 clamp_u32(const u32 min, const u32 val, const u32 max)
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{
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if (val > max)
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return max;
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if (val < min)
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return min;
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return val;
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}
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#endif /* COMMONLIB_CLAMP_H */
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@ -1,6 +1,7 @@
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/* SPDX-License-Identifier: GPL-2.0-only */
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/* This file is part of the coreboot project. */
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#include <commonlib/clamp.h>
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#include <console/console.h>
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#include <console/usb.h>
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#include <delay.h>
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@ -9,24 +10,25 @@
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#include "raminit_common.h"
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#include "raminit_tables.h"
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/* Frequency multiplier */
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static u32 get_FRQ(u32 tCK, u8 base_freq)
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{
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const u32 FRQ = 256000 / (tCK * base_freq);
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#define IVB_MIN_DCLK_133_MULT 3
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#define IVB_MAX_DCLK_133_MULT 10
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#define IVB_MIN_DCLK_100_MULT 7
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#define IVB_MAX_DCLK_100_MULT 12
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if (base_freq == 100) {
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if (FRQ > 12)
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return 12;
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if (FRQ < 7)
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return 7;
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} else {
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if (FRQ > 10)
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return 10;
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if (FRQ < 3)
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return 3;
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/* Frequency multiplier */
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static u32 get_FRQ(const ramctr_timing *ctrl)
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{
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const u32 FRQ = 256000 / (ctrl->tCK * ctrl->base_freq);
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if (IS_IVY_CPU(ctrl->cpu)) {
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if (ctrl->base_freq == 100)
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return clamp_u32(IVB_MIN_DCLK_100_MULT, FRQ, IVB_MAX_DCLK_100_MULT);
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if (ctrl->base_freq == 133)
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return clamp_u32(IVB_MIN_DCLK_133_MULT, FRQ, IVB_MAX_DCLK_133_MULT);
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}
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return FRQ;
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die("Unsupported CPU or base frequency.");
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}
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/* Get REFI based on frequency index, tREFI = 7.8usec */
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@ -204,7 +206,7 @@ static void find_cas_tck(ramctr_timing *ctrl)
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}
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/* Frequency multiplier */
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ctrl->FRQ = get_FRQ(ctrl->tCK, ctrl->base_freq);
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ctrl->FRQ = get_FRQ(ctrl);
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printk(BIOS_DEBUG, "Selected DRAM frequency: %u MHz\n", NS2MHZ_DIV256 / ctrl->tCK);
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printk(BIOS_DEBUG, "Selected CAS latency : %uT\n", val);
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