src/northbridge/intel/sandybridge/raminit_sandy.c

/* SPDX-License-Identifier: GPL-2.0-only */
/* This file is part of the coreboot project. */

#include <console/console.h>
#include <console/usb.h>
#include <delay.h>
#include "raminit_native.h"
#include "raminit_common.h"

/* Frequency multiplier */
static u32 get_FRQ(u32 tCK)
{
	const u32 FRQ = 256000 / (tCK * BASEFREQ);

	if (FRQ > 8)
		return 8;
	if (FRQ < 3)
		return 3;

	return FRQ;
}

/* Get REFI based on MC frequency */
static u32 get_REFI(u32 tCK)
{
	static const u32 frq_refi_map[] = {
	/* FRQ:    3,    4,    5,    6,    7,    8, */
		3120, 4160, 5200, 6240, 7280, 8320,
	};
	return frq_refi_map[get_FRQ(tCK) - 3];
}

/* Get XSOffset based on MC frequency */
static u8 get_XSOffset(u32 tCK)
{
	static const u8 frq_xs_map[] = {
	/* FRQ: 3,  4,  5,  6,  7,  8, */
		4,  6,  7,  8, 10, 11,
	};
	return frq_xs_map[get_FRQ(tCK) - 3];
}

/* Get MOD based on MC frequency */
static u8 get_MOD(u32 tCK)
{
	static const u8 frq_mod_map[] = {
	/* FRQ:  3,  4,  5,  6,  7,  8, */
		12, 12, 12, 12, 15, 16,
	};
	return frq_mod_map[get_FRQ(tCK) - 3];
}

/* Get Write Leveling Output delay based on MC frequency */
static u8 get_WLO(u32 tCK)
{
	static const u8 frq_wlo_map[] = {
	/* FRQ: 3, 4, 5, 6, 7, 8, */
		4, 5, 6, 6, 8, 8,
	};
	return frq_wlo_map[get_FRQ(tCK) - 3];
}

/* Get CKE based on MC frequency */
static u8 get_CKE(u32 tCK)
{
	static const u8 frq_cke_map[] = {
	/* FRQ: 3, 4, 5, 6, 7, 8, */
		3, 3, 4, 4, 5, 6,
	};
	return frq_cke_map[get_FRQ(tCK) - 3];
}

/* Get XPDLL based on MC frequency */
static u8 get_XPDLL(u32 tCK)
{
	static const u8 frq_xpdll_map[] = {
	/* FRQ:  3,  4,  5,  6,  7,  8, */
		10, 13, 16, 20, 23, 26,
	};
	return frq_xpdll_map[get_FRQ(tCK) - 3];
}

/* Get XP based on MC frequency */
static u8 get_XP(u32 tCK)
{
	static const u8 frq_xp_map[] = {
	/* FRQ: 3, 4, 5, 6, 7, 8, */
		3, 4, 4, 5, 6, 7,
	};
	return frq_xp_map[get_FRQ(tCK) - 3];
}

/* Get AONPD based on MC frequency */
static u8 get_AONPD(u32 tCK)
{
	static const u8 frq_aonpd_map[] = {
	/* FRQ: 3,  4,  5,  6,  7,  8, */
		4,  5,  6,  8,  8, 10,
	};
	return frq_aonpd_map[get_FRQ(tCK) - 3];
}

/* Get COMP2 based on MC frequency */
static u32 get_COMP2(u32 tCK)
{
	static const u32 frq_comp2_map[] = {
	/* FRQ:          3,          4,          5,          6,          7,          8, */
		0x0D6BEDCC, 0x0CE7C34C, 0x0CA57A4C, 0x0C6369CC, 0x0C42514C, 0x0C21410C,
	};
	return frq_comp2_map[get_FRQ(tCK) - 3];
}

static void snb_normalize_tclk(u32 *tclk)
{
	if (*tclk <= TCK_1066MHZ) {
		*tclk = TCK_1066MHZ;
	} else if (*tclk <= TCK_933MHZ) {
		*tclk = TCK_933MHZ;
	} else if (*tclk <= TCK_800MHZ) {
		*tclk = TCK_800MHZ;
	} else if (*tclk <= TCK_666MHZ) {
		*tclk = TCK_666MHZ;
	} else if (*tclk <= TCK_533MHZ) {
		*tclk = TCK_533MHZ;
	} else if (*tclk <= TCK_400MHZ) {
		*tclk = TCK_400MHZ;
	} else {
		*tclk = 0;
	}
}

static void find_cas_tck(ramctr_timing *ctrl)
{
	u8 val;

	/* Find CAS latency */
	while (1) {
		/*
		 * Normalising tCK before computing clock could potentially
		 * result in a lower selected CAS, which is desired.
		 */
		snb_normalize_tclk(&(ctrl->tCK));
		if (!(ctrl->tCK))
			die("Couldn't find compatible clock / CAS settings\n");

		val = DIV_ROUND_UP(ctrl->tAA, ctrl->tCK);
		printk(BIOS_DEBUG, "Trying CAS %u, tCK %u.\n", val, ctrl->tCK);
		for (; val <= MAX_CAS; val++)
			if ((ctrl->cas_supported >> (val - MIN_CAS)) & 1)
				break;

		if (val == (MAX_CAS + 1)) {
			ctrl->tCK++;
			continue;
		} else {
			printk(BIOS_DEBUG, "Found compatible clock, CAS pair.\n");
			break;
		}
	}

	printk(BIOS_DEBUG, "Selected DRAM frequency: %u MHz\n", NS2MHZ_DIV256 / ctrl->tCK);
	printk(BIOS_DEBUG, "Selected CAS latency   : %uT\n", val);
	ctrl->CAS = val;
}

static void dram_timing(ramctr_timing *ctrl)
{
	/*
	 * On Sandy Bridge, the maximum supported DDR3 frequency is 1066MHz (DDR3 2133).
	 * Cap it for faster DIMMs, and align it to the closest JEDEC standard frequency.
	 */
	if (ctrl->tCK == TCK_1066MHZ) {
		ctrl->edge_offset[0] = 16;
		ctrl->edge_offset[1] = 7;
		ctrl->edge_offset[2] = 7;
		ctrl->timC_offset[0] = 18;
		ctrl->timC_offset[1] = 7;
		ctrl->timC_offset[2] = 7;
		ctrl->pi_coding_threshold = 13;

	} else if (ctrl->tCK == TCK_933MHZ) {
		ctrl->edge_offset[0] = 14;
		ctrl->edge_offset[1] = 6;
		ctrl->edge_offset[2] = 6;
		ctrl->timC_offset[0] = 15;
		ctrl->timC_offset[1] = 6;
		ctrl->timC_offset[2] = 6;
		ctrl->pi_coding_threshold = 15;

	} else if (ctrl->tCK == TCK_800MHZ) {
		ctrl->edge_offset[0] = 13;
		ctrl->edge_offset[1] = 5;
		ctrl->edge_offset[2] = 5;
		ctrl->timC_offset[0] = 14;
		ctrl->timC_offset[1] = 5;
		ctrl->timC_offset[2] = 5;
		ctrl->pi_coding_threshold = 15;

	} else if (ctrl->tCK == TCK_666MHZ) {
		ctrl->edge_offset[0] = 10;
		ctrl->edge_offset[1] = 4;
		ctrl->edge_offset[2] = 4;
		ctrl->timC_offset[0] = 11;
		ctrl->timC_offset[1] = 4;
		ctrl->timC_offset[2] = 4;
		ctrl->pi_coding_threshold = 16;

	} else if (ctrl->tCK == TCK_533MHZ) {
		ctrl->edge_offset[0] = 8;
		ctrl->edge_offset[1] = 3;
		ctrl->edge_offset[2] = 3;
		ctrl->timC_offset[0] = 9;
		ctrl->timC_offset[1] = 3;
		ctrl->timC_offset[2] = 3;
		ctrl->pi_coding_threshold = 17;

	} else  {
		ctrl->tCK = TCK_400MHZ;
		ctrl->edge_offset[0] = 6;
		ctrl->edge_offset[1] = 2;
		ctrl->edge_offset[2] = 2;
		ctrl->timC_offset[0] = 6;
		ctrl->timC_offset[1] = 2;
		ctrl->timC_offset[2] = 2;
		ctrl->pi_coding_threshold = 17;
	}

	/* Initial phase between CLK/CMD pins */
	ctrl->pi_code_offset = (256000 / ctrl->tCK) / 66;

	/* DLL_CONFIG_MDLL_W_TIMER */
	ctrl->mdll_wake_delay = (128000 / ctrl->tCK) + 3;

	if (ctrl->tCWL)
		ctrl->CWL = DIV_ROUND_UP(ctrl->tCWL, ctrl->tCK);
	else
		ctrl->CWL = get_CWL(ctrl->tCK);

	printk(BIOS_DEBUG, "Selected CWL latency   : %uT\n", ctrl->CWL);

	/* Find tRCD */
	ctrl->tRCD = DIV_ROUND_UP(ctrl->tRCD, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tRCD          : %uT\n", ctrl->tRCD);

	ctrl->tRP  = DIV_ROUND_UP(ctrl->tRP,  ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tRP           : %uT\n", ctrl->tRP);

	/* Find tRAS */
	ctrl->tRAS = DIV_ROUND_UP(ctrl->tRAS, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tRAS          : %uT\n", ctrl->tRAS);

	/* Find tWR */
	ctrl->tWR  = DIV_ROUND_UP(ctrl->tWR,  ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tWR           : %uT\n", ctrl->tWR);

	/* Find tFAW */
	ctrl->tFAW = DIV_ROUND_UP(ctrl->tFAW, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tFAW          : %uT\n", ctrl->tFAW);

	/* Find tRRD */
	ctrl->tRRD = DIV_ROUND_UP(ctrl->tRRD, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tRRD          : %uT\n", ctrl->tRRD);

	/* Find tRTP */
	ctrl->tRTP = DIV_ROUND_UP(ctrl->tRTP, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tRTP          : %uT\n", ctrl->tRTP);

	/* Find tWTR */
	ctrl->tWTR = DIV_ROUND_UP(ctrl->tWTR, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tWTR          : %uT\n", ctrl->tWTR);

	/* Refresh-to-Active or Refresh-to-Refresh (tRFC) */
	ctrl->tRFC = DIV_ROUND_UP(ctrl->tRFC, ctrl->tCK);
	printk(BIOS_DEBUG, "Selected tRFC          : %uT\n", ctrl->tRFC);

	ctrl->tREFI     =     get_REFI(ctrl->tCK);
	ctrl->tMOD      =      get_MOD(ctrl->tCK);
	ctrl->tXSOffset = get_XSOffset(ctrl->tCK);
	ctrl->tWLO      =      get_WLO(ctrl->tCK);
	ctrl->tCKE      =      get_CKE(ctrl->tCK);
	ctrl->tXPDLL    =    get_XPDLL(ctrl->tCK);
	ctrl->tXP       =       get_XP(ctrl->tCK);
	ctrl->tAONPD    =    get_AONPD(ctrl->tCK);
}

static void dram_freq(ramctr_timing *ctrl)
{
	if (ctrl->tCK > TCK_400MHZ) {
		printk(BIOS_ERR,
			"DRAM frequency is under lowest supported frequency (400 MHz). "
			"Increasing to 400 MHz as last resort");
		ctrl->tCK = TCK_400MHZ;
	}

	while (1) {
		u8 val2;
		u32 reg1 = 0;

		/* Step 1 - Set target PCU frequency */
		find_cas_tck(ctrl);

		/* Frequency multiplier */
		const u32 FRQ = get_FRQ(ctrl->tCK);

		/*
		 * The PLL will never lock if the required frequency is already set.
		 * Exit early to prevent a system hang.
		 */
		reg1 = MCHBAR32(MC_BIOS_DATA);
		val2 = (u8) reg1;
		if (val2)
			return;

		/* Step 1 - Select frequency in the MCU */
		reg1 = FRQ;
		reg1 |= 0x80000000;	/* set running bit */
		MCHBAR32(MC_BIOS_REQ) = reg1;
		int i=0;
		printk(BIOS_DEBUG, "PLL busy... ");
		while (reg1 & 0x80000000) {
			udelay(10);
			i++;
			reg1 = MCHBAR32(MC_BIOS_REQ);
		}
		printk(BIOS_DEBUG, "done in %d us\n", i * 10);

		/* Step 2 - Verify lock frequency */
		reg1 = MCHBAR32(MC_BIOS_DATA);
		val2 = (u8) reg1;
		if (val2 >= FRQ) {
			printk(BIOS_DEBUG, "MCU frequency is set at : %d MHz\n",
			       (1000 << 8) / ctrl->tCK);
			return;
		}
		printk(BIOS_DEBUG, "PLL didn't lock. Retrying at lower frequency\n");
		ctrl->tCK++;
	}
}

static void dram_ioregs(ramctr_timing *ctrl)
{
	u32 reg;

	int channel;

	/* IO clock */
	FOR_ALL_CHANNELS {
		MCHBAR32(GDCRCLKRANKSUSED_ch(channel)) = ctrl->rankmap[channel];
	}

	/* IO command */
	FOR_ALL_CHANNELS {
		MCHBAR32(GDCRCTLRANKSUSED_ch(channel)) = ctrl->rankmap[channel];
	}

	/* IO control */
	FOR_ALL_POPULATED_CHANNELS {
		program_timings(ctrl, channel);
	}

	/* Perform RCOMP */
	printram("RCOMP...");
	while (!(MCHBAR32(RCOMP_TIMER) & (1 << 16)))
		;

	printram("done\n");

	/* Set COMP2 */
	MCHBAR32(CRCOMPOFST2) = get_COMP2(ctrl->tCK);
	printram("COMP2 done\n");

	/* Set COMP1 */
	FOR_ALL_POPULATED_CHANNELS {
		reg = MCHBAR32(CRCOMPOFST1_ch(channel));
		reg = (reg & ~0x00000e00) | (1 <<  9);	/* ODT */
		reg = (reg & ~0x00e00000) | (1 << 21);	/* clk drive up */
		reg = (reg & ~0x38000000) | (1 << 27);	/* ctl drive up */
		MCHBAR32(CRCOMPOFST1_ch(channel)) = reg;
	}
	printram("COMP1 done\n");

	printram("FORCE RCOMP and wait 20us...");
	MCHBAR32(M_COMP) |= (1 << 8);
	udelay(20);
	printram("done\n");
}

int try_init_dram_ddr3_snb(ramctr_timing *ctrl, int fast_boot, int s3_resume, int me_uma_size)
{
	int err;

	printk(BIOS_DEBUG, "Starting SandyBridge RAM training (%d).\n", fast_boot);

	if (!fast_boot) {
		/* Find fastest common supported parameters */
		dram_find_common_params(ctrl);

		dram_dimm_mapping(ctrl);
	}

	/* Set MC frequency */
	dram_freq(ctrl);

	if (!fast_boot) {
		/* Calculate timings */
		dram_timing(ctrl);
	}

	/* Set version register */
	MCHBAR32(MRC_REVISION) = 0xc04eb002;

	/* Enable crossover */
	dram_xover(ctrl);

	/* Set timing and refresh registers */
	dram_timing_regs(ctrl);

	/* Power mode preset */
	MCHBAR32(PM_THML_STAT) = 0x5500;

	/* Set scheduler chicken bits */
	MCHBAR32(SCHED_CBIT) = 0x10100005;

	/* Set up watermarks and starvation counter */
	set_wmm_behavior(ctrl->cpu);

	/* Clear IO reset bit */
	MCHBAR32(MC_INIT_STATE_G) &= ~(1 << 5);

	/* Set MAD-DIMM registers */
	dram_dimm_set_mapping(ctrl);
	printk(BIOS_DEBUG, "Done dimm mapping\n");

	/* Zone config */
	dram_zones(ctrl, 1);

	/* Set memory map */
	dram_memorymap(ctrl, me_uma_size);
	printk(BIOS_DEBUG, "Done memory map\n");

	/* Set IO registers */
	dram_ioregs(ctrl);
	printk(BIOS_DEBUG, "Done io registers\n");

	udelay(1);

	if (fast_boot) {
		restore_timings(ctrl);
	} else {
		/* Do JEDEC DDR3 reset sequence */
		dram_jedecreset(ctrl);
		printk(BIOS_DEBUG, "Done jedec reset\n");

		/* MRS commands */
		dram_mrscommands(ctrl);
		printk(BIOS_DEBUG, "Done MRS commands\n");

		/* Prepare for memory training */
		prepare_training(ctrl);

		err = read_training(ctrl);
		if (err)
			return err;

		err = write_training(ctrl);
		if (err)
			return err;

		printram("CP5a\n");

		err = discover_edges(ctrl);
		if (err)
			return err;

		printram("CP5b\n");

		err = command_training(ctrl);
		if (err)
			return err;

		printram("CP5c\n");

		err = discover_edges_write(ctrl);
		if (err)
			return err;

		err = discover_timC_write(ctrl);
		if (err)
			return err;

		normalize_training(ctrl);
	}

	set_read_write_timings(ctrl);

	write_controller_mr(ctrl);

	if (!s3_resume) {
		err = channel_test(ctrl);
		if (err)
			return err;
	}

	return 0;
}