--- /dev/null
+/* 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);
+}
git.openpandora.org / pandora-kernel.git / blobdiff