Ben Dooks | 140780a | 2009-07-30 23:23:37 +0100 | [diff] [blame^] | 1 | /* linux/arch/arm/plat-s3c24xx/s3c2412-iotiming.c |
| 2 | * |
| 3 | * Copyright (c) 2006,2008 Simtec Electronics |
| 4 | * http://armlinux.simtec.co.uk/ |
| 5 | * Ben Dooks <ben@simtec.co.uk> |
| 6 | * |
| 7 | * S3C2412/S3C2443 (PL093 based) IO timing support |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/ioport.h> |
| 18 | #include <linux/cpufreq.h> |
| 19 | #include <linux/sysdev.h> |
| 20 | #include <linux/delay.h> |
| 21 | #include <linux/clk.h> |
| 22 | #include <linux/err.h> |
| 23 | |
| 24 | #include <linux/amba/pl093.h> |
| 25 | |
| 26 | #include <asm/mach/arch.h> |
| 27 | #include <asm/mach/map.h> |
| 28 | |
| 29 | #include <mach/regs-s3c2412-mem.h> |
| 30 | |
| 31 | #include <plat/cpu.h> |
| 32 | #include <plat/cpu-freq-core.h> |
| 33 | #include <plat/clock.h> |
| 34 | |
| 35 | #define print_ns(x) ((x) / 10), ((x) % 10) |
| 36 | |
| 37 | /** |
| 38 | * s3c2412_print_timing - print timing infromation via printk. |
| 39 | * @pfx: The prefix to print each line with. |
| 40 | * @iot: The IO timing information |
| 41 | */ |
| 42 | static void s3c2412_print_timing(const char *pfx, struct s3c_iotimings *iot) |
| 43 | { |
| 44 | struct s3c2412_iobank_timing *bt; |
| 45 | unsigned int bank; |
| 46 | |
| 47 | for (bank = 0; bank < MAX_BANKS; bank++) { |
| 48 | bt = iot->bank[bank].io_2412; |
| 49 | if (!bt) |
| 50 | continue; |
| 51 | |
| 52 | printk(KERN_DEBUG "%s: %d: idcy=%d.%d wstrd=%d.%d wstwr=%d,%d" |
| 53 | "wstoen=%d.%d wstwen=%d.%d wstbrd=%d.%d\n", pfx, bank, |
| 54 | print_ns(bt->idcy), |
| 55 | print_ns(bt->wstrd), |
| 56 | print_ns(bt->wstwr), |
| 57 | print_ns(bt->wstoen), |
| 58 | print_ns(bt->wstwen), |
| 59 | print_ns(bt->wstbrd)); |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * to_div - turn a cycle length into a divisor setting. |
| 65 | * @cyc_tns: The cycle time in 10ths of nanoseconds. |
| 66 | * @clk_tns: The clock period in 10ths of nanoseconds. |
| 67 | */ |
| 68 | static inline unsigned int to_div(unsigned int cyc_tns, unsigned int clk_tns) |
| 69 | { |
| 70 | return cyc_tns ? DIV_ROUND_UP(cyc_tns, clk_tns) : 0; |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * calc_timing - calculate timing divisor value and check in range. |
| 75 | * @hwtm: The hardware timing in 10ths of nanoseconds. |
| 76 | * @clk_tns: The clock period in 10ths of nanoseconds. |
| 77 | * @err: Pointer to err variable to update in event of failure. |
| 78 | */ |
| 79 | static unsigned int calc_timing(unsigned int hwtm, unsigned int clk_tns, |
| 80 | unsigned int *err) |
| 81 | { |
| 82 | unsigned int ret = to_div(hwtm, clk_tns); |
| 83 | |
| 84 | if (ret > 0xf) |
| 85 | *err = -EINVAL; |
| 86 | |
| 87 | return ret; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * s3c2412_calc_bank - calculate the bank divisor settings. |
| 92 | * @cfg: The current frequency configuration. |
| 93 | * @bt: The bank timing. |
| 94 | */ |
| 95 | static int s3c2412_calc_bank(struct s3c_cpufreq_config *cfg, |
| 96 | struct s3c2412_iobank_timing *bt) |
| 97 | { |
| 98 | unsigned int hclk = cfg->freq.hclk_tns; |
| 99 | int err = 0; |
| 100 | |
| 101 | bt->smbidcyr = calc_timing(bt->idcy, hclk, &err); |
| 102 | bt->smbwstrd = calc_timing(bt->wstrd, hclk, &err); |
| 103 | bt->smbwstwr = calc_timing(bt->wstwr, hclk, &err); |
| 104 | bt->smbwstoen = calc_timing(bt->wstoen, hclk, &err); |
| 105 | bt->smbwstwen = calc_timing(bt->wstwen, hclk, &err); |
| 106 | bt->smbwstbrd = calc_timing(bt->wstbrd, hclk, &err); |
| 107 | |
| 108 | return err; |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * s3c2412_iotiming_calc - calculate all the bank divisor settings. |
| 113 | * @cfg: The current frequency configuration. |
| 114 | * @iot: The bank timing information. |
| 115 | * |
| 116 | * Calculate the timing information for all the banks that are |
| 117 | * configured as IO, using s3c2412_calc_bank(). |
| 118 | */ |
| 119 | int s3c2412_iotiming_calc(struct s3c_cpufreq_config *cfg, |
| 120 | struct s3c_iotimings *iot) |
| 121 | { |
| 122 | struct s3c2412_iobank_timing *bt; |
| 123 | int bank; |
| 124 | int ret; |
| 125 | |
| 126 | for (bank = 0; bank < MAX_BANKS; bank++) { |
| 127 | bt = iot->bank[bank].io_2412; |
| 128 | if (!bt) |
| 129 | continue; |
| 130 | |
| 131 | ret = s3c2412_calc_bank(cfg, bt); |
| 132 | if (ret) { |
| 133 | printk(KERN_ERR "%s: cannot calculate bank %d io\n", |
| 134 | __func__, bank); |
| 135 | goto err; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | return 0; |
| 140 | err: |
| 141 | return ret; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * s3c2412_iotiming_set - set the timing information |
| 146 | * @cfg: The current frequency configuration. |
| 147 | * @iot: The bank timing information. |
| 148 | * |
| 149 | * Set the IO bank information from the details calculated earlier from |
| 150 | * calling s3c2412_iotiming_calc(). |
| 151 | */ |
| 152 | void s3c2412_iotiming_set(struct s3c_cpufreq_config *cfg, |
| 153 | struct s3c_iotimings *iot) |
| 154 | { |
| 155 | struct s3c2412_iobank_timing *bt; |
| 156 | void __iomem *regs; |
| 157 | int bank; |
| 158 | |
| 159 | /* set the io timings from the specifier */ |
| 160 | |
| 161 | for (bank = 0; bank < MAX_BANKS; bank++) { |
| 162 | bt = iot->bank[bank].io_2412; |
| 163 | if (!bt) |
| 164 | continue; |
| 165 | |
| 166 | regs = S3C2412_SSMC_BANK(bank); |
| 167 | |
| 168 | __raw_writel(bt->smbidcyr, regs + SMBIDCYR); |
| 169 | __raw_writel(bt->smbwstrd, regs + SMBWSTRDR); |
| 170 | __raw_writel(bt->smbwstwr, regs + SMBWSTWRR); |
| 171 | __raw_writel(bt->smbwstoen, regs + SMBWSTOENR); |
| 172 | __raw_writel(bt->smbwstwen, regs + SMBWSTWENR); |
| 173 | __raw_writel(bt->smbwstbrd, regs + SMBWSTBRDR); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | static inline unsigned int s3c2412_decode_timing(unsigned int clock, u32 reg) |
| 178 | { |
| 179 | return (reg & 0xf) * clock; |
| 180 | } |
| 181 | |
| 182 | static void s3c2412_iotiming_getbank(struct s3c_cpufreq_config *cfg, |
| 183 | struct s3c2412_iobank_timing *bt, |
| 184 | unsigned int bank) |
| 185 | { |
| 186 | unsigned long clk = cfg->freq.hclk_tns; /* ssmc clock??? */ |
| 187 | void __iomem *regs = S3C2412_SSMC_BANK(bank); |
| 188 | |
| 189 | bt->idcy = s3c2412_decode_timing(clk, __raw_readl(regs + SMBIDCYR)); |
| 190 | bt->wstrd = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTRDR)); |
| 191 | bt->wstoen = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTOENR)); |
| 192 | bt->wstwen = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTWENR)); |
| 193 | bt->wstbrd = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTBRDR)); |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * bank_is_io - return true if bank is (possibly) IO. |
| 198 | * @bank: The bank number. |
| 199 | * @bankcfg: The value of S3C2412_EBI_BANKCFG. |
| 200 | */ |
| 201 | static inline bool bank_is_io(unsigned int bank, u32 bankcfg) |
| 202 | { |
| 203 | if (bank < 2) |
| 204 | return true; |
| 205 | |
| 206 | return !(bankcfg & (1 << bank)); |
| 207 | } |
| 208 | |
| 209 | int s3c2412_iotiming_get(struct s3c_cpufreq_config *cfg, |
| 210 | struct s3c_iotimings *timings) |
| 211 | { |
| 212 | struct s3c2412_iobank_timing *bt; |
| 213 | u32 bankcfg = __raw_readl(S3C2412_EBI_BANKCFG); |
| 214 | unsigned int bank; |
| 215 | |
| 216 | /* look through all banks to see what is currently set. */ |
| 217 | |
| 218 | for (bank = 0; bank < MAX_BANKS; bank++) { |
| 219 | if (!bank_is_io(bank, bankcfg)) |
| 220 | continue; |
| 221 | |
| 222 | bt = kzalloc(sizeof(struct s3c2412_iobank_timing), GFP_KERNEL); |
| 223 | if (!bt) { |
| 224 | printk(KERN_ERR "%s: no memory for bank\n", __func__); |
| 225 | return -ENOMEM; |
| 226 | } |
| 227 | |
| 228 | timings->bank[bank].io_2412 = bt; |
| 229 | s3c2412_iotiming_getbank(cfg, bt, bank); |
| 230 | } |
| 231 | |
| 232 | s3c2412_print_timing("get", timings); |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | /* this is in here as it is so small, it doesn't currently warrant a file |
| 237 | * to itself. We expect that any s3c24xx needing this is going to also |
| 238 | * need the iotiming support. |
| 239 | */ |
| 240 | void s3c2412_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg) |
| 241 | { |
| 242 | struct s3c_cpufreq_board *board = cfg->board; |
| 243 | u32 refresh; |
| 244 | |
| 245 | WARN_ON(board == NULL); |
| 246 | |
| 247 | /* Reduce both the refresh time (in ns) and the frequency (in MHz) |
| 248 | * down to ensure that we do not overflow 32 bit numbers. |
| 249 | * |
| 250 | * This should work for HCLK up to 133MHz and refresh period up |
| 251 | * to 30usec. |
| 252 | */ |
| 253 | |
| 254 | refresh = (cfg->freq.hclk / 100) * (board->refresh / 10); |
| 255 | refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */ |
| 256 | refresh &= ((1 << 16) - 1); |
| 257 | |
| 258 | s3c_freq_dbg("%s: refresh value %u\n", __func__, (unsigned int)refresh); |
| 259 | |
| 260 | __raw_writel(refresh, S3C2412_REFRESH); |
| 261 | } |