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ARM: S3C24XX: CPUFREQ: S3C2412/S3C2443 IO timing support

Add IO bank timing support for S3C2412/S3C2443.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Ben Dooks 2009-07-30 23:23:37 +01:00 committed by Ben Dooks
parent 2540003686
commit 140780ab5a
6 changed files with 329 additions and 1 deletions

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@ -32,9 +32,12 @@ config S3C2412_PM
help
Internal config node to apply S3C2412 power management
# Note, the S3C2412 IOtiming support is in plat-s3c24xx
config S3C2412_CPUFREQ
bool
depends on CPU_FREQ_S3C24XX && CPU_S3C2412
select S3C2412_IOTIMING
default y
help
CPU Frequency scaling support for S3C2412 and S3C2413 SoC CPUs.

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@ -185,6 +185,10 @@ static struct s3c_cpufreq_info s3c2412_cpufreq_info = {
.set_divs = s3c2412_cpufreq_setdivs,
.calc_divs = s3c2412_cpufreq_calcdivs,
.calc_iotiming = s3c2412_iotiming_calc,
.set_iotiming = s3c2412_iotiming_set,
.get_iotiming = s3c2412_iotiming_get,
.resume_clocks = s3c2412_setup_clocks,
};

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@ -157,6 +157,15 @@ config S3C2410_CPUFREQ_UTILS
Internal node to select timing code that is common to the s3c2410
and s3c2440/s3c244 cpu frequency support.
# cpu frequency support common to s3c2412, s3c2413 and s3c2442
config S3C2412_IOTIMING
bool
depends on CPU_FREQ_S3C24XX && (CPU_S3C2412 || CPU_S3C2443)
help
Intel node to select io timing code that is common to the s3c2412
and the s3c2443.
config MACH_SMDK
bool
help

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@ -40,6 +40,7 @@ obj-$(CONFIG_S3C2410_CLOCK) += s3c2410-clock.o
obj-$(CONFIG_S3C2410_DMA) += dma.o
obj-$(CONFIG_S3C24XX_ADC) += adc.o
obj-$(CONFIG_S3C2410_IOTIMING) += s3c2410-iotiming.o
obj-$(CONFIG_S3C2412_IOTIMING) += s3c2412-iotiming.o
obj-$(CONFIG_S3C2410_CPUFREQ_UTILS) += s3c2410-cpufreq-utils.o
# device specific setup and/or initialisation

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@ -42,8 +42,44 @@ struct s3c2410_iobank_timing {
unsigned char nwait_en; /* nWait enabled for bank. */
};
/**
* struct s3c2412_iobank_timing - io timings for PL092 (S3C2412) style IO
* @idcy: The idle cycle time between transactions.
* @wstrd: nCS release to end of read cycle.
* @wstwr: nCS release to end of write cycle.
* @wstoen: nCS assertion to nOE assertion time.
* @wstwen: nCS assertion to nWE assertion time.
* @wstbrd: Burst ready delay.
* @smbidcyr: Register cache for smbidcyr value.
* @smbwstrd: Register cache for smbwstrd value.
* @smbwstwr: Register cache for smbwstwr value.
* @smbwstoen: Register cache for smbwstoen value.
* @smbwstwen: Register cache for smbwstwen value.
* @smbwstbrd: Register cache for smbwstbrd value.
*
* Timing information for a IO bank on an S3C2412 or similar system which
* uses a PL093 block.
*/
struct s3c2412_iobank_timing {
unsigned int idcy;
unsigned int wstrd;
unsigned int wstwr;
unsigned int wstoen;
unsigned int wstwen;
unsigned int wstbrd;
/* register cache */
unsigned char smbidcyr;
unsigned char smbwstrd;
unsigned char smbwstwr;
unsigned char smbwstoen;
unsigned char smbwstwen;
unsigned char smbwstbrd;
};
union s3c_iobank {
struct s3c2410_iobank_timing *io_2410;
struct s3c2410_iobank_timing *io_2410;
struct s3c2412_iobank_timing *io_2412;
};
/**
@ -174,6 +210,20 @@ extern void s3c2410_iotiming_set(struct s3c_cpufreq_config *cfg,
extern void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg);
/* S3C2412 compatible routines */
extern int s3c2412_iotiming_get(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *timings);
extern int s3c2412_iotiming_get(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *timings);
extern int s3c2412_iotiming_calc(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *iot);
extern void s3c2412_iotiming_set(struct s3c_cpufreq_config *cfg,
struct s3c_iotimings *iot);
#ifdef CONFIG_CPU_FREQ_S3C24XX_DEBUG
#define s3c_freq_dbg(x...) printk(KERN_INFO x)
#else

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@ -0,0 +1,261 @@
/* 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/sysdev.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.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_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);
}