/* linux/arch/arm/plat-s3c24xx/s3c2412-iotiming.c
*
* Copyright (c) 2006-2008 Simtec Electronics
* http://armlinux.simtec.co.uk/
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2412/S3C2443 (PL093 based) IO timing support
*
* 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/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/cpufreq.h>
#include <linux/seq_file.h>
#include <linux/sysdev.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/amba/pl093.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <mach/regs-s3c2412-mem.h>
#include <plat/cpu.h>
#include <plat/cpu-freq-core.h>
#include <plat/clock.h>
#define print_ns(x) ((x) / 10), ((x) % 10)
/**
* s3c2412_print_timing - print timing infromation via printk.
* @pfx: The prefix to print each line with.
* @iot: The IO timing information
*/
static void s3c2412_print_timing(const char *pfx, struct s3c_iotimings *iot)
{
struct s3c2412_iobank_timing *bt;
unsigned int bank;
for (bank = 0; bank < MAX_BANKS; bank++) {
bt = iot->bank[bank].io_2412;
if (!bt)
continue;
printk(KERN_DEBUG "%s: %d: idcy=%d.%d wstrd=%d.%d wstwr=%d,%d"
"wstoen=%d.%d wstwen=%d.%d wstbrd=%d.%d\n", pfx, bank,
print_ns(bt->idcy),
print_ns(bt->wstrd),
print_ns(bt->wstwr),
print_ns(bt->wstoen),
print_ns(bt->wstwen),
print_ns(bt->wstbrd));
}
}
/**
* to_div - turn a cycle length into a divisor setting.
* @cyc_tns: The cycle time in 10ths of nanoseconds.
* @clk_tns: The clock period in 10ths of nanoseconds.
*/
static inline unsigned int to_div(unsigned int cyc_tns, unsigned int clk_tns)
{
return cyc_tns ? DIV_ROUND_UP(cyc_tns, clk_tns) : 0;
}
/**
* calc_timing - calculate timing divisor value and check in range.
* @hwtm: The hardware timing in 10ths of nanoseconds.
* @clk_tns: The clock period in 10ths of nanoseconds.
* @err: Pointer to err variable to update in event of failure.
*/
static unsigned int calc_timing(unsigned int hwtm, unsigned int clk_tns,
unsigned int *err)
{
unsigned int ret = to_div(hwtm, clk_tns);
if (ret > 0xf)
*err = -EINVAL;
return ret;
}
/**
* s3c2412_calc_bank - calculate the bank divisor settings.
* @cfg: The current frequency configuration.
* @bt: The bank timing.
*/
static int s3c2412_calc_bank(struct s3c_cpufreq_config *cfg,
struct s3c2412_iobank_timing *bt)
{
unsigned int hclk = cfg->freq.hclk_tns;
int err = 0;
bt->smbidcyr = calc_timing(bt->idcy, hclk, &err);
bt->smbwstrd = calc_timing(bt->wstrd, hclk, &err);
bt->smbwstwr = calc_timing(bt->wstwr, hclk, &err);
bt->smbwstoen = calc_timing(bt->wstoen, hclk, &err);
bt->smbwstwen = calc_timing(bt->wstwen, hclk, &err);
bt->smbwstbrd = calc_timing(bt->wstbrd, hclk, &err);
return err;
}
/**
* s3c2412_iotiming_debugfs - debugfs show io bank timing information
* @seq: The seq_file to write output to using seq_printf().
* @cfg: The current configuration.
* @iob: The IO bank information to decode.
*/
void s3c2412_iotiming_debugfs(struct seq_file *seq,
struct s3c_cpufreq_config *cfg,
union s3c_iobank *iob)
{
struct s3c2412_iobank_timing *bt = iob->io_2412;
seq_printf(seq,
"\tRead: idcy=%d.%d wstrd=%d.%d wstwr=%d,%d"
"wstoen=%d.%d wstwen=%d.%d wstbrd=%d.%d\n",
print_ns(bt->idcy),
print_ns(bt->wstrd),
print_ns(bt->wstwr),
print_ns(bt->wstoen),
print_ns(bt->wstwen),
print_ns(bt->wstbrd));
}
/**
* s3c2412_iotiming_calc - calculate all the bank divisor settings.
* @cfg: The current frequency configuration.
* @iot: The bank timing information.
*
* Calculate the timing information for all the banks that are
* configured as IO, using s3c2412_calc_bank().
*/
int s3c2412_iotiming_calc(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *iot)
{
struct s3c2412_iobank_timing *bt;
int bank;
int ret;
for (bank = 0; bank < MAX_BANKS; bank++) {
bt = iot->bank[bank].io_2412;
if (!bt)
continue;
ret = s3c2412_calc_bank(cfg, bt);
if (ret) {
printk(KERN_ERR "%s: cannot calculate bank %d io\n",
__func__, bank);
goto err;
}
}
return 0;
err:
return ret;
}
/**
* s3c2412_iotiming_set - set the timing information
* @cfg: The current frequency configuration.
* @iot: The bank timing information.
*
* Set the IO bank information from the details calculated earlier from
* calling s3c2412_iotiming_calc().
*/
void s3c2412_iotiming_set(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *iot)
{
struct s3c2412_iobank_timing *bt;
void __iomem *regs;
int bank;
/* set the io timings from the specifier */
for (bank = 0; bank < MAX_BANKS; bank++) {
bt = iot->bank[bank].io_2412;
if (!bt)
continue;
regs = S3C2412_SSMC_BANK(bank);
__raw_writel(bt->smbidcyr, regs + SMBIDCYR);
__raw_writel(bt->smbwstrd, regs + SMBWSTRDR);
__raw_writel(bt->smbwstwr, regs + SMBWSTWRR);
__raw_writel(bt->smbwstoen, regs + SMBWSTOENR);
__raw_writel(bt->smbwstwen, regs + SMBWSTWENR);
__raw_writel(bt->smbwstbrd, regs + SMBWSTBRDR);
}
}
static inline unsigned int s3c2412_decode_timing(unsigned int clock, u32 reg)
{
return (reg & 0xf) * clock;
}
static void s3c2412_iotiming_getbank(struct s3c_cpufreq_config *cfg,
struct s3c2412_iobank_timing *bt,
unsigned int bank)
{
unsigned long clk = cfg->freq.hclk_tns; /* ssmc clock??? */
void __iomem *regs = S3C2412_SSMC_BANK(bank);
bt->idcy = s3c2412_decode_timing(clk, __raw_readl(regs + SMBIDCYR));
bt->wstrd = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTRDR));
bt->wstoen = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTOENR));
bt->wstwen = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTWENR));
bt->wstbrd = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTBRDR));
}
/**
* bank_is_io - return true if bank is (possibly) IO.
* @bank: The bank number.
* @bankcfg: The value of S3C2412_EBI_BANKCFG.
*/
static inline bool bank_is_io(unsigned int bank, u32 bankcfg)
{
if (bank < 2)
return true;
return !(bankcfg & (1 << bank));
}
int s3c2412_iotiming_get(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *timings)
{
struct s3c2412_iobank_timing *bt;
u32 bankcfg = __raw_readl(S3C2412_EBI_BANKCFG);
unsigned int bank;
/* look through all banks to see what is currently set. */
for (bank = 0; bank < MAX_BANKS; bank++) {
if (!bank_is_io(bank, bankcfg))
continue;
bt = kzalloc(sizeof(struct s3c2412_iobank_timing), GFP_KERNEL);
if (!bt) {
printk(KERN_ERR "%s: no memory for bank\n", __func__);
return -ENOMEM;
}
timings->bank[bank].io_2412 = bt;
s3c2412_iotiming_getbank(cfg, bt, bank);
}
s3c2412_print_timing("get", timings);
return 0;
}
/* this is in here as it is so small, it doesn't currently warrant a file
* to itself. We expect that any s3c24xx needing this is going to also
* need the iotiming support.
*/
void s3c2412_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
{
struct s3c_cpufreq_board *board = cfg->board;
u32 refresh;
WARN_ON(board == NULL);
/* Reduce both the refresh time (in ns) and the frequency (in MHz)
* down to ensure that we do not overflow 32 bit numbers.
*
* This should work for HCLK up to 133MHz and refresh period up
* to 30usec.
*/
refresh = (cfg->freq.hclk / 100) * (board->refresh / 10);
refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */
refresh &= ((1 << 16) - 1);
s3c_freq_dbg("%s: refresh value %u\n", __func__, (unsigned int)refresh);
__raw_writel(refresh, S3C2412_REFRESH);
}
