/*
* SDRC register values for RX51
*
* Copyright (C) 2008 Nokia Corporation
*
* Lauri Leukkunen <lauri.leukkunen@nokia.com>
*
* Original code by Juha Yrjola <juha.yrjola@solidboot.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <plat/io.h>
#include <plat/common.h>
#include <plat/clock.h>
#include <plat/sdrc.h>
/* In picoseconds, except for tREF (ns), tXP, tCKE, tWTR (clks) */
struct sdram_timings {
u32 casl;
u32 tDAL;
u32 tDPL;
u32 tRRD;
u32 tRCD;
u32 tRP;
u32 tRAS;
u32 tRC;
u32 tRFC;
u32 tXSR;
u32 tREF; /* in ns */
u32 tXP;
u32 tCKE;
u32 tWTR;
};
struct omap_sdrc_params rx51_sdrc_params[4];
static const struct sdram_timings rx51_timings[] = {
{
.casl = 3,
.tDAL = 33000,
.tDPL = 15000,
.tRRD = 12000,
.tRCD = 22500,
.tRP = 18000,
.tRAS = 42000,
.tRC = 66000,
.tRFC = 138000,
.tXSR = 200000,
.tREF = 7800,
.tXP = 2,
.tCKE = 2,
.tWTR = 2
},
};
static unsigned long sdrc_get_fclk_period(long rate)
{
/* In picoseconds */
return 1000000000 / rate;
}
static unsigned int sdrc_ps_to_ticks(unsigned int time_ps, long rate)
{
unsigned long tick_ps;
/* Calculate in picosecs to yield more exact results */
tick_ps = sdrc_get_fclk_period(rate);
return (time_ps + tick_ps - 1) / tick_ps;
}
#undef DEBUG
#ifdef DEBUG
static int set_sdrc_timing_regval(u32 *regval, int st_bit, int end_bit,
int ticks, long rate, const char *name)
#else
static int set_sdrc_timing_regval(u32 *regval, int st_bit, int end_bit,
int ticks)
#endif
{
int mask, nr_bits;
nr_bits = end_bit - st_bit + 1;
if (ticks >= 1 << nr_bits)
return -1;
mask = (1 << nr_bits) - 1;
*regval &= ~(mask << st_bit);
*regval |= ticks << st_bit;
#ifdef DEBUG
printk(KERN_INFO "SDRC %s: %i ticks %i ns\n", name, ticks,
(unsigned int)sdrc_get_fclk_period(rate) * ticks /
1000);
#endif
return 0;
}
#ifdef DEBUG
#define SDRC_SET_ONE(reg, st, end, field, rate) \
if (set_sdrc_timing_regval((reg), (st), (end), \
rx51_timings->field, (rate), #field) < 0) \
err = -1;
#else
#define SDRC_SET_ONE(reg, st, end, field, rate) \
if (set_sdrc_timing_regval((reg), (st), (end), \
rx51_timings->field) < 0) \
err = -1;
#endif
#ifdef DEBUG
static int set_sdrc_timing_regval_ps(u32 *regval, int st_bit, int end_bit,
int time, long rate, const char *name)
#else
static int set_sdrc_timing_regval_ps(u32 *regval, int st_bit, int end_bit,
int time, long rate)
#endif
{
int ticks, ret;
ret = 0;
if (time == 0)
ticks = 0;
else
ticks = sdrc_ps_to_ticks(time, rate);
#ifdef DEBUG
ret = set_sdrc_timing_regval(regval, st_bit, end_bit, ticks,
rate, name);
#else
ret = set_sdrc_timing_regval(regval, st_bit, end_bit, ticks);
#endif
return ret;
}
#ifdef DEBUG
#define SDRC_SET_ONE_PS(reg, st, end, field, rate) \
if (set_sdrc_timing_regval_ps((reg), (st), (end), \
rx51_timings->field, \
(rate), #field) < 0) \
err = -1;
#else
#define SDRC_SET_ONE_PS(reg, st, end, field, rate) \
if (set_sdrc_timing_regval_ps((reg), (st), (end), \
rx51_timings->field, (rate)) < 0) \
err = -1;
#endif
static int sdrc_timings(int id, long rate)
{
u32 ticks_per_ms;
u32 rfr, l;
u32 actim_ctrla = 0, actim_ctrlb = 0;
u32 rfr_ctrl;
int err = 0;
long l3_rate = rate / 1000;
SDRC_SET_ONE_PS(&actim_ctrla, 0, 4, tDAL, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 6, 8, tDPL, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 9, 11, tRRD, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 12, 14, tRCD, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 15, 17, tRP, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 18, 21, tRAS, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 22, 26, tRC, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrla, 27, 31, tRFC, l3_rate);
SDRC_SET_ONE_PS(&actim_ctrlb, 0, 7, tXSR, l3_rate);
SDRC_SET_ONE(&actim_ctrlb, 8, 10, tXP, l3_rate);
SDRC_SET_ONE(&actim_ctrlb, 12, 14, tCKE, l3_rate);
SDRC_SET_ONE(&actim_ctrlb, 16, 17, tWTR, l3_rate);
ticks_per_ms = l3_rate;
rfr = rx51_timings[0].tREF * ticks_per_ms / 1000000;
if (rfr > 65535 + 50)
rfr = 65535;
else
rfr -= 50;
#ifdef DEBUG
printk(KERN_INFO "SDRC tREF: %i ticks\n", rfr);
#endif
l = rfr << 8;
rfr_ctrl = l | 0x1; /* autorefresh, reload counter with 1xARCV */
rx51_sdrc_params[id].rate = rate;
rx51_sdrc_params[id].actim_ctrla = actim_ctrla;
rx51_sdrc_params[id].actim_ctrlb = actim_ctrlb;
rx51_sdrc_params[id].rfr_ctrl = rfr_ctrl;
rx51_sdrc_params[id].mr = 0x32;
rx51_sdrc_params[id + 1].rate = 0;
return err;
}
struct omap_sdrc_params *rx51_get_sdram_timings(void)
{
int err;
err = sdrc_timings(0, 41500000);
err |= sdrc_timings(1, 83000000);
err |= sdrc_timings(2, 166000000);
return &rx51_sdrc_params[0];
}
