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