blob: bd064c05c4738584e91934765347eb4f85bfdaea [file] [log] [blame]
Kukjin Kim09ec1d72013-01-31 16:54:38 -08001/*
Ben Dooksccae9412009-11-13 22:54:14 +00002 * Copyright (c) 2006-2008 Simtec Electronics
Ben Dooks140780a2009-07-30 23:23:37 +01003 * http://armlinux.simtec.co.uk/
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2412/S3C2443 (PL093 based) IO timing support
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11*/
12
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/interrupt.h>
16#include <linux/ioport.h>
17#include <linux/cpufreq.h>
Ben Dookse6d197a2009-07-30 23:23:42 +010018#include <linux/seq_file.h>
Kay Sieversedbaa602011-12-21 16:26:03 -080019#include <linux/device.h>
Ben Dooks140780a2009-07-30 23:23:37 +010020#include <linux/delay.h>
21#include <linux/clk.h>
22#include <linux/err.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Ben Dooks140780a2009-07-30 23:23:37 +010024
25#include <linux/amba/pl093.h>
26
27#include <asm/mach/arch.h>
28#include <asm/mach/map.h>
29
Ben Dooks140780a2009-07-30 23:23:37 +010030#include <plat/cpu.h>
31#include <plat/cpu-freq-core.h>
32#include <plat/clock.h>
33
Viresh Kumarf023f8d2013-04-04 12:54:15 +000034#include <mach/s3c2412.h>
Kukjin Kimd3c01e72013-02-01 17:13:37 -080035
Ben Dooks140780a2009-07-30 23:23:37 +010036#define print_ns(x) ((x) / 10), ((x) % 10)
37
38/**
39 * s3c2412_print_timing - print timing infromation via printk.
40 * @pfx: The prefix to print each line with.
41 * @iot: The IO timing information
42 */
43static void s3c2412_print_timing(const char *pfx, struct s3c_iotimings *iot)
44{
45 struct s3c2412_iobank_timing *bt;
46 unsigned int bank;
47
48 for (bank = 0; bank < MAX_BANKS; bank++) {
49 bt = iot->bank[bank].io_2412;
50 if (!bt)
51 continue;
52
53 printk(KERN_DEBUG "%s: %d: idcy=%d.%d wstrd=%d.%d wstwr=%d,%d"
54 "wstoen=%d.%d wstwen=%d.%d wstbrd=%d.%d\n", pfx, bank,
55 print_ns(bt->idcy),
56 print_ns(bt->wstrd),
57 print_ns(bt->wstwr),
58 print_ns(bt->wstoen),
59 print_ns(bt->wstwen),
60 print_ns(bt->wstbrd));
61 }
62}
63
64/**
65 * to_div - turn a cycle length into a divisor setting.
66 * @cyc_tns: The cycle time in 10ths of nanoseconds.
67 * @clk_tns: The clock period in 10ths of nanoseconds.
68 */
69static inline unsigned int to_div(unsigned int cyc_tns, unsigned int clk_tns)
70{
71 return cyc_tns ? DIV_ROUND_UP(cyc_tns, clk_tns) : 0;
72}
73
74/**
75 * calc_timing - calculate timing divisor value and check in range.
76 * @hwtm: The hardware timing in 10ths of nanoseconds.
77 * @clk_tns: The clock period in 10ths of nanoseconds.
78 * @err: Pointer to err variable to update in event of failure.
79 */
80static unsigned int calc_timing(unsigned int hwtm, unsigned int clk_tns,
81 unsigned int *err)
82{
83 unsigned int ret = to_div(hwtm, clk_tns);
84
85 if (ret > 0xf)
86 *err = -EINVAL;
87
88 return ret;
89}
90
91/**
92 * s3c2412_calc_bank - calculate the bank divisor settings.
93 * @cfg: The current frequency configuration.
94 * @bt: The bank timing.
95 */
96static int s3c2412_calc_bank(struct s3c_cpufreq_config *cfg,
97 struct s3c2412_iobank_timing *bt)
98{
99 unsigned int hclk = cfg->freq.hclk_tns;
100 int err = 0;
101
102 bt->smbidcyr = calc_timing(bt->idcy, hclk, &err);
103 bt->smbwstrd = calc_timing(bt->wstrd, hclk, &err);
104 bt->smbwstwr = calc_timing(bt->wstwr, hclk, &err);
105 bt->smbwstoen = calc_timing(bt->wstoen, hclk, &err);
106 bt->smbwstwen = calc_timing(bt->wstwen, hclk, &err);
107 bt->smbwstbrd = calc_timing(bt->wstbrd, hclk, &err);
108
109 return err;
110}
111
112/**
Ben Dookse6d197a2009-07-30 23:23:42 +0100113 * s3c2412_iotiming_debugfs - debugfs show io bank timing information
114 * @seq: The seq_file to write output to using seq_printf().
115 * @cfg: The current configuration.
116 * @iob: The IO bank information to decode.
117*/
118void s3c2412_iotiming_debugfs(struct seq_file *seq,
119 struct s3c_cpufreq_config *cfg,
120 union s3c_iobank *iob)
121{
122 struct s3c2412_iobank_timing *bt = iob->io_2412;
123
124 seq_printf(seq,
125 "\tRead: idcy=%d.%d wstrd=%d.%d wstwr=%d,%d"
126 "wstoen=%d.%d wstwen=%d.%d wstbrd=%d.%d\n",
127 print_ns(bt->idcy),
128 print_ns(bt->wstrd),
129 print_ns(bt->wstwr),
130 print_ns(bt->wstoen),
131 print_ns(bt->wstwen),
132 print_ns(bt->wstbrd));
133}
134
135/**
Ben Dooks140780a2009-07-30 23:23:37 +0100136 * s3c2412_iotiming_calc - calculate all the bank divisor settings.
137 * @cfg: The current frequency configuration.
138 * @iot: The bank timing information.
139 *
140 * Calculate the timing information for all the banks that are
141 * configured as IO, using s3c2412_calc_bank().
142 */
143int s3c2412_iotiming_calc(struct s3c_cpufreq_config *cfg,
144 struct s3c_iotimings *iot)
145{
146 struct s3c2412_iobank_timing *bt;
147 int bank;
148 int ret;
149
150 for (bank = 0; bank < MAX_BANKS; bank++) {
151 bt = iot->bank[bank].io_2412;
152 if (!bt)
153 continue;
154
155 ret = s3c2412_calc_bank(cfg, bt);
156 if (ret) {
157 printk(KERN_ERR "%s: cannot calculate bank %d io\n",
158 __func__, bank);
159 goto err;
160 }
161 }
162
163 return 0;
164 err:
165 return ret;
166}
167
168/**
169 * s3c2412_iotiming_set - set the timing information
170 * @cfg: The current frequency configuration.
171 * @iot: The bank timing information.
172 *
173 * Set the IO bank information from the details calculated earlier from
174 * calling s3c2412_iotiming_calc().
175 */
176void s3c2412_iotiming_set(struct s3c_cpufreq_config *cfg,
177 struct s3c_iotimings *iot)
178{
179 struct s3c2412_iobank_timing *bt;
180 void __iomem *regs;
181 int bank;
182
183 /* set the io timings from the specifier */
184
185 for (bank = 0; bank < MAX_BANKS; bank++) {
186 bt = iot->bank[bank].io_2412;
187 if (!bt)
188 continue;
189
190 regs = S3C2412_SSMC_BANK(bank);
191
192 __raw_writel(bt->smbidcyr, regs + SMBIDCYR);
193 __raw_writel(bt->smbwstrd, regs + SMBWSTRDR);
194 __raw_writel(bt->smbwstwr, regs + SMBWSTWRR);
195 __raw_writel(bt->smbwstoen, regs + SMBWSTOENR);
196 __raw_writel(bt->smbwstwen, regs + SMBWSTWENR);
197 __raw_writel(bt->smbwstbrd, regs + SMBWSTBRDR);
198 }
199}
200
201static inline unsigned int s3c2412_decode_timing(unsigned int clock, u32 reg)
202{
203 return (reg & 0xf) * clock;
204}
205
206static void s3c2412_iotiming_getbank(struct s3c_cpufreq_config *cfg,
207 struct s3c2412_iobank_timing *bt,
208 unsigned int bank)
209{
210 unsigned long clk = cfg->freq.hclk_tns; /* ssmc clock??? */
211 void __iomem *regs = S3C2412_SSMC_BANK(bank);
212
213 bt->idcy = s3c2412_decode_timing(clk, __raw_readl(regs + SMBIDCYR));
214 bt->wstrd = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTRDR));
215 bt->wstoen = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTOENR));
216 bt->wstwen = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTWENR));
217 bt->wstbrd = s3c2412_decode_timing(clk, __raw_readl(regs + SMBWSTBRDR));
218}
219
220/**
221 * bank_is_io - return true if bank is (possibly) IO.
222 * @bank: The bank number.
223 * @bankcfg: The value of S3C2412_EBI_BANKCFG.
224 */
225static inline bool bank_is_io(unsigned int bank, u32 bankcfg)
226{
227 if (bank < 2)
228 return true;
229
230 return !(bankcfg & (1 << bank));
231}
232
233int s3c2412_iotiming_get(struct s3c_cpufreq_config *cfg,
234 struct s3c_iotimings *timings)
235{
236 struct s3c2412_iobank_timing *bt;
237 u32 bankcfg = __raw_readl(S3C2412_EBI_BANKCFG);
238 unsigned int bank;
239
240 /* look through all banks to see what is currently set. */
241
242 for (bank = 0; bank < MAX_BANKS; bank++) {
243 if (!bank_is_io(bank, bankcfg))
244 continue;
245
246 bt = kzalloc(sizeof(struct s3c2412_iobank_timing), GFP_KERNEL);
247 if (!bt) {
248 printk(KERN_ERR "%s: no memory for bank\n", __func__);
249 return -ENOMEM;
250 }
251
252 timings->bank[bank].io_2412 = bt;
253 s3c2412_iotiming_getbank(cfg, bt, bank);
254 }
255
256 s3c2412_print_timing("get", timings);
257 return 0;
258}
259
260/* this is in here as it is so small, it doesn't currently warrant a file
261 * to itself. We expect that any s3c24xx needing this is going to also
262 * need the iotiming support.
263 */
264void s3c2412_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
265{
266 struct s3c_cpufreq_board *board = cfg->board;
267 u32 refresh;
268
269 WARN_ON(board == NULL);
270
271 /* Reduce both the refresh time (in ns) and the frequency (in MHz)
272 * down to ensure that we do not overflow 32 bit numbers.
273 *
274 * This should work for HCLK up to 133MHz and refresh period up
275 * to 30usec.
276 */
277
278 refresh = (cfg->freq.hclk / 100) * (board->refresh / 10);
279 refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */
280 refresh &= ((1 << 16) - 1);
281
282 s3c_freq_dbg("%s: refresh value %u\n", __func__, (unsigned int)refresh);
283
284 __raw_writel(refresh, S3C2412_REFRESH);
285}