/*
   * SDRC register values for Nokia boards
   *
   * Copyright (C) 2008, 2010-2011 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 "common.h"
  #include "sdram-nokia.h"
  #include "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;
  };
  
  static const struct sdram_timings nokia_97dot6mhz_timings[] = {
  	{
  		.casl = 3,
  		.tDAL = 30725,
  		.tDPL = 15362,
  		.tRRD = 10241,
  		.tRCD = 20483,
  		.tRP = 15362,
  		.tRAS = 40967,
  		.tRC = 56330,
  		.tRFC = 138266,
  		.tXSR = 204839,
  
  		.tREF = 7798,
  
  		.tXP = 2,
  		.tCKE = 4,
  		.tWTR = 2,
  	},
  };
  
  static const struct sdram_timings nokia_166mhz_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 const struct sdram_timings nokia_195dot2mhz_timings[] = {
  	{
  		.casl = 3,
  		.tDAL = 30725,
  		.tDPL = 15362,
  		.tRRD = 10241,
  		.tRCD = 20483,
  		.tRP = 15362,
  		.tRAS = 40967,
  		.tRC = 56330,
  		.tRFC = 138266,
  		.tXSR = 204839,
  
  		.tREF = 7752,
  
  		.tXP = 2,
  		.tCKE = 4,
  		.tWTR = 2,
  	},
  };
  
  static const struct sdram_timings nokia_200mhz_timings[] = {
  	{
  		.casl = 3,
  		.tDAL = 30000,
  		.tDPL = 15000,
  		.tRRD = 10000,
  		.tRCD = 20000,
  		.tRP = 15000,
  		.tRAS = 40000,
  		.tRC = 55000,
  		.tRFC = 140000,
  		.tXSR = 200000,
  
  		.tREF = 7800,
  
  		.tXP = 2,
  		.tCKE = 4,
  		.tWTR = 2
  	},
  };
  
  static const struct {
  	long rate;
  	struct sdram_timings const *data;
  } nokia_timings[] = {
  	{ 83000000, nokia_166mhz_timings },
  	{ 97600000, nokia_97dot6mhz_timings },
  	{ 100000000, nokia_200mhz_timings },
  	{ 166000000, nokia_166mhz_timings },
  	{ 195200000, nokia_195dot2mhz_timings },
  	{ 200000000, nokia_200mhz_timings },
  };
  static struct omap_sdrc_params nokia_sdrc_params[ARRAY_SIZE(nokia_timings) + 1];
  
  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
  ", 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), \
  			memory_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), \
  			memory_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), \
  			memory_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), \
  			memory_timings->field, (rate)) < 0) \
  		err = -1;
  #endif
  
  static int sdrc_timings(int id, long rate,
  			const struct sdram_timings *memory_timings)
  {
  	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 = memory_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
  ", rfr);
  #endif
  
  	l = rfr << 8;
  	rfr_ctrl = l | 0x1; /* autorefresh, reload counter with 1xARCV */
  
  	nokia_sdrc_params[id].rate = rate;
  	nokia_sdrc_params[id].actim_ctrla = actim_ctrla;
  	nokia_sdrc_params[id].actim_ctrlb = actim_ctrlb;
  	nokia_sdrc_params[id].rfr_ctrl = rfr_ctrl;
  	nokia_sdrc_params[id].mr = 0x32;
  
  	nokia_sdrc_params[id + 1].rate = 0;
  
  	return err;
  }
  
  struct omap_sdrc_params *nokia_get_sdram_timings(void)
  {
  	int err = 0;
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(nokia_timings); i++) {
  		err |= sdrc_timings(i, nokia_timings[i].rate,
  				       nokia_timings[i].data);
  		if (err)
  			pr_err("%s: error with rate %ld: %d
  ", __func__,
  			       nokia_timings[i].rate, err);
  	}
  
  	return err ? NULL : nokia_sdrc_params;
  }