diff options
author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
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committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /arch/arm/mach-s3c2443/clock.c | |
parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) |
Diffstat (limited to 'arch/arm/mach-s3c2443/clock.c')
-rw-r--r-- | arch/arm/mach-s3c2443/clock.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2443/clock.c b/arch/arm/mach-s3c2443/clock.c new file mode 100644 index 00000000000..38058af4897 --- /dev/null +++ b/arch/arm/mach-s3c2443/clock.c | |||
@@ -0,0 +1,368 @@ | |||
1 | /* linux/arch/arm/mach-s3c2443/clock.c | ||
2 | * | ||
3 | * Copyright (c) 2007, 2010 Simtec Electronics | ||
4 | * Ben Dooks <ben@simtec.co.uk> | ||
5 | * | ||
6 | * S3C2443 Clock control 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 as published by | ||
10 | * the Free Software Foundation; either version 2 of the License, or | ||
11 | * (at your option) any later version. | ||
12 | * | ||
13 | * This program is distributed in the hope that it will be useful, | ||
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
16 | * GNU General Public License for more details. | ||
17 | * | ||
18 | * You should have received a copy of the GNU General Public License | ||
19 | * along with this program; if not, write to the Free Software | ||
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
21 | */ | ||
22 | |||
23 | #include <linux/init.h> | ||
24 | |||
25 | #include <linux/module.h> | ||
26 | #include <linux/kernel.h> | ||
27 | #include <linux/list.h> | ||
28 | #include <linux/errno.h> | ||
29 | #include <linux/err.h> | ||
30 | #include <linux/sysdev.h> | ||
31 | #include <linux/clk.h> | ||
32 | #include <linux/mutex.h> | ||
33 | #include <linux/serial_core.h> | ||
34 | #include <linux/io.h> | ||
35 | |||
36 | #include <asm/mach/map.h> | ||
37 | |||
38 | #include <mach/hardware.h> | ||
39 | |||
40 | #include <mach/regs-s3c2443-clock.h> | ||
41 | |||
42 | #include <plat/cpu-freq.h> | ||
43 | |||
44 | #include <plat/s3c2443.h> | ||
45 | #include <plat/clock.h> | ||
46 | #include <plat/clock-clksrc.h> | ||
47 | #include <plat/cpu.h> | ||
48 | |||
49 | /* We currently have to assume that the system is running | ||
50 | * from the XTPll input, and that all ***REFCLKs are being | ||
51 | * fed from it, as we cannot read the state of OM[4] from | ||
52 | * software. | ||
53 | * | ||
54 | * It would be possible for each board initialisation to | ||
55 | * set the correct muxing at initialisation | ||
56 | */ | ||
57 | |||
58 | /* clock selections */ | ||
59 | |||
60 | static struct clk clk_i2s_ext = { | ||
61 | .name = "i2s-ext", | ||
62 | }; | ||
63 | |||
64 | /* armdiv | ||
65 | * | ||
66 | * this clock is sourced from msysclk and can have a number of | ||
67 | * divider values applied to it to then be fed into armclk. | ||
68 | */ | ||
69 | |||
70 | /* armdiv divisor table */ | ||
71 | |||
72 | static unsigned int armdiv[16] = { | ||
73 | [S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 1, | ||
74 | [S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 2, | ||
75 | [S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 3, | ||
76 | [S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 4, | ||
77 | [S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 6, | ||
78 | [S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 8, | ||
79 | [S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 12, | ||
80 | [S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 16, | ||
81 | }; | ||
82 | |||
83 | static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0) | ||
84 | { | ||
85 | clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK; | ||
86 | |||
87 | return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]; | ||
88 | } | ||
89 | |||
90 | static unsigned long s3c2443_armclk_roundrate(struct clk *clk, | ||
91 | unsigned long rate) | ||
92 | { | ||
93 | unsigned long parent = clk_get_rate(clk->parent); | ||
94 | unsigned long calc; | ||
95 | unsigned best = 256; /* bigger than any value */ | ||
96 | unsigned div; | ||
97 | int ptr; | ||
98 | |||
99 | for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) { | ||
100 | div = armdiv[ptr]; | ||
101 | calc = parent / div; | ||
102 | if (calc <= rate && div < best) | ||
103 | best = div; | ||
104 | } | ||
105 | |||
106 | return parent / best; | ||
107 | } | ||
108 | |||
109 | static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate) | ||
110 | { | ||
111 | unsigned long parent = clk_get_rate(clk->parent); | ||
112 | unsigned long calc; | ||
113 | unsigned div; | ||
114 | unsigned best = 256; /* bigger than any value */ | ||
115 | int ptr; | ||
116 | int val = -1; | ||
117 | |||
118 | for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) { | ||
119 | div = armdiv[ptr]; | ||
120 | calc = parent / div; | ||
121 | if (calc <= rate && div < best) { | ||
122 | best = div; | ||
123 | val = ptr; | ||
124 | } | ||
125 | } | ||
126 | |||
127 | if (val >= 0) { | ||
128 | unsigned long clkcon0; | ||
129 | |||
130 | clkcon0 = __raw_readl(S3C2443_CLKDIV0); | ||
131 | clkcon0 &= ~S3C2443_CLKDIV0_ARMDIV_MASK; | ||
132 | clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT; | ||
133 | __raw_writel(clkcon0, S3C2443_CLKDIV0); | ||
134 | } | ||
135 | |||
136 | return (val == -1) ? -EINVAL : 0; | ||
137 | } | ||
138 | |||
139 | static struct clk clk_armdiv = { | ||
140 | .name = "armdiv", | ||
141 | .parent = &clk_msysclk.clk, | ||
142 | .ops = &(struct clk_ops) { | ||
143 | .round_rate = s3c2443_armclk_roundrate, | ||
144 | .set_rate = s3c2443_armclk_setrate, | ||
145 | }, | ||
146 | }; | ||
147 | |||
148 | /* armclk | ||
149 | * | ||
150 | * this is the clock fed into the ARM core itself, from armdiv or from hclk. | ||
151 | */ | ||
152 | |||
153 | static struct clk *clk_arm_sources[] = { | ||
154 | [0] = &clk_armdiv, | ||
155 | [1] = &clk_h, | ||
156 | }; | ||
157 | |||
158 | static struct clksrc_clk clk_arm = { | ||
159 | .clk = { | ||
160 | .name = "armclk", | ||
161 | }, | ||
162 | .sources = &(struct clksrc_sources) { | ||
163 | .sources = clk_arm_sources, | ||
164 | .nr_sources = ARRAY_SIZE(clk_arm_sources), | ||
165 | }, | ||
166 | .reg_src = { .reg = S3C2443_CLKDIV0, .size = 1, .shift = 13 }, | ||
167 | }; | ||
168 | |||
169 | /* hsspi | ||
170 | * | ||
171 | * high-speed spi clock, sourced from esysclk | ||
172 | */ | ||
173 | |||
174 | static struct clksrc_clk clk_hsspi = { | ||
175 | .clk = { | ||
176 | .name = "hsspi", | ||
177 | .parent = &clk_esysclk.clk, | ||
178 | .ctrlbit = S3C2443_SCLKCON_HSSPICLK, | ||
179 | .enable = s3c2443_clkcon_enable_s, | ||
180 | }, | ||
181 | .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 }, | ||
182 | }; | ||
183 | |||
184 | |||
185 | /* clk_hsmcc_div | ||
186 | * | ||
187 | * this clock is sourced from epll, and is fed through a divider, | ||
188 | * to a mux controlled by sclkcon where either it or a extclk can | ||
189 | * be fed to the hsmmc block | ||
190 | */ | ||
191 | |||
192 | static struct clksrc_clk clk_hsmmc_div = { | ||
193 | .clk = { | ||
194 | .name = "hsmmc-div", | ||
195 | .devname = "s3c-sdhci.1", | ||
196 | .parent = &clk_esysclk.clk, | ||
197 | }, | ||
198 | .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 6 }, | ||
199 | }; | ||
200 | |||
201 | static int s3c2443_setparent_hsmmc(struct clk *clk, struct clk *parent) | ||
202 | { | ||
203 | unsigned long clksrc = __raw_readl(S3C2443_SCLKCON); | ||
204 | |||
205 | clksrc &= ~(S3C2443_SCLKCON_HSMMCCLK_EXT | | ||
206 | S3C2443_SCLKCON_HSMMCCLK_EPLL); | ||
207 | |||
208 | if (parent == &clk_epll) | ||
209 | clksrc |= S3C2443_SCLKCON_HSMMCCLK_EPLL; | ||
210 | else if (parent == &clk_ext) | ||
211 | clksrc |= S3C2443_SCLKCON_HSMMCCLK_EXT; | ||
212 | else | ||
213 | return -EINVAL; | ||
214 | |||
215 | if (clk->usage > 0) { | ||
216 | __raw_writel(clksrc, S3C2443_SCLKCON); | ||
217 | } | ||
218 | |||
219 | clk->parent = parent; | ||
220 | return 0; | ||
221 | } | ||
222 | |||
223 | static int s3c2443_enable_hsmmc(struct clk *clk, int enable) | ||
224 | { | ||
225 | return s3c2443_setparent_hsmmc(clk, clk->parent); | ||
226 | } | ||
227 | |||
228 | static struct clk clk_hsmmc = { | ||
229 | .name = "hsmmc-if", | ||
230 | .devname = "s3c-sdhci.1", | ||
231 | .parent = &clk_hsmmc_div.clk, | ||
232 | .enable = s3c2443_enable_hsmmc, | ||
233 | .ops = &(struct clk_ops) { | ||
234 | .set_parent = s3c2443_setparent_hsmmc, | ||
235 | }, | ||
236 | }; | ||
237 | |||
238 | /* i2s_eplldiv | ||
239 | * | ||
240 | * This clock is the output from the I2S divisor of ESYSCLK, and is separate | ||
241 | * from the mux that comes after it (cannot merge into one single clock) | ||
242 | */ | ||
243 | |||
244 | static struct clksrc_clk clk_i2s_eplldiv = { | ||
245 | .clk = { | ||
246 | .name = "i2s-eplldiv", | ||
247 | .parent = &clk_esysclk.clk, | ||
248 | }, | ||
249 | .reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 12, }, | ||
250 | }; | ||
251 | |||
252 | /* i2s-ref | ||
253 | * | ||
254 | * i2s bus reference clock, selectable from external, esysclk or epllref | ||
255 | * | ||
256 | * Note, this used to be two clocks, but was compressed into one. | ||
257 | */ | ||
258 | |||
259 | struct clk *clk_i2s_srclist[] = { | ||
260 | [0] = &clk_i2s_eplldiv.clk, | ||
261 | [1] = &clk_i2s_ext, | ||
262 | [2] = &clk_epllref.clk, | ||
263 | [3] = &clk_epllref.clk, | ||
264 | }; | ||
265 | |||
266 | static struct clksrc_clk clk_i2s = { | ||
267 | .clk = { | ||
268 | .name = "i2s-if", | ||
269 | .ctrlbit = S3C2443_SCLKCON_I2SCLK, | ||
270 | .enable = s3c2443_clkcon_enable_s, | ||
271 | |||
272 | }, | ||
273 | .sources = &(struct clksrc_sources) { | ||
274 | .sources = clk_i2s_srclist, | ||
275 | .nr_sources = ARRAY_SIZE(clk_i2s_srclist), | ||
276 | }, | ||
277 | .reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 14 }, | ||
278 | }; | ||
279 | |||
280 | /* standard clock definitions */ | ||
281 | |||
282 | static struct clk init_clocks_off[] = { | ||
283 | { | ||
284 | .name = "sdi", | ||
285 | .parent = &clk_p, | ||
286 | .enable = s3c2443_clkcon_enable_p, | ||
287 | .ctrlbit = S3C2443_PCLKCON_SDI, | ||
288 | }, { | ||
289 | .name = "iis", | ||
290 | .parent = &clk_p, | ||
291 | .enable = s3c2443_clkcon_enable_p, | ||
292 | .ctrlbit = S3C2443_PCLKCON_IIS, | ||
293 | }, { | ||
294 | .name = "spi", | ||
295 | .devname = "s3c2410-spi.0", | ||
296 | .parent = &clk_p, | ||
297 | .enable = s3c2443_clkcon_enable_p, | ||
298 | .ctrlbit = S3C2443_PCLKCON_SPI0, | ||
299 | }, { | ||
300 | .name = "spi", | ||
301 | .devname = "s3c2410-spi.1", | ||
302 | .parent = &clk_p, | ||
303 | .enable = s3c2443_clkcon_enable_p, | ||
304 | .ctrlbit = S3C2443_PCLKCON_SPI1, | ||
305 | } | ||
306 | }; | ||
307 | |||
308 | static struct clk init_clocks[] = { | ||
309 | }; | ||
310 | |||
311 | /* clocks to add straight away */ | ||
312 | |||
313 | static struct clksrc_clk *clksrcs[] __initdata = { | ||
314 | &clk_arm, | ||
315 | &clk_i2s_eplldiv, | ||
316 | &clk_i2s, | ||
317 | &clk_hsspi, | ||
318 | &clk_hsmmc_div, | ||
319 | }; | ||
320 | |||
321 | static struct clk *clks[] __initdata = { | ||
322 | &clk_hsmmc, | ||
323 | &clk_armdiv, | ||
324 | }; | ||
325 | |||
326 | void __init_or_cpufreq s3c2443_setup_clocks(void) | ||
327 | { | ||
328 | s3c2443_common_setup_clocks(s3c2443_get_mpll, s3c2443_fclk_div); | ||
329 | } | ||
330 | |||
331 | void __init s3c2443_init_clocks(int xtal) | ||
332 | { | ||
333 | unsigned long epllcon = __raw_readl(S3C2443_EPLLCON); | ||
334 | int ptr; | ||
335 | |||
336 | clk_epll.rate = s3c2443_get_epll(epllcon, xtal); | ||
337 | clk_epll.parent = &clk_epllref.clk; | ||
338 | |||
339 | s3c2443_common_init_clocks(xtal, s3c2443_get_mpll, s3c2443_fclk_div); | ||
340 | |||
341 | s3c2443_setup_clocks(); | ||
342 | |||
343 | s3c24xx_register_clocks(clks, ARRAY_SIZE(clks)); | ||
344 | |||
345 | for (ptr = 0; ptr < ARRAY_SIZE(clksrcs); ptr++) | ||
346 | s3c_register_clksrc(clksrcs[ptr], 1); | ||
347 | |||
348 | /* register clocks from clock array */ | ||
349 | |||
350 | s3c_register_clocks(init_clocks, ARRAY_SIZE(init_clocks)); | ||
351 | |||
352 | /* We must be careful disabling the clocks we are not intending to | ||
353 | * be using at boot time, as subsystems such as the LCD which do | ||
354 | * their own DMA requests to the bus can cause the system to lockup | ||
355 | * if they where in the middle of requesting bus access. | ||
356 | * | ||
357 | * Disabling the LCD clock if the LCD is active is very dangerous, | ||
358 | * and therefore the bootloader should be careful to not enable | ||
359 | * the LCD clock if it is not needed. | ||
360 | */ | ||
361 | |||
362 | /* install (and disable) the clocks we do not need immediately */ | ||
363 | |||
364 | s3c_register_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off)); | ||
365 | s3c_disable_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off)); | ||
366 | |||
367 | s3c_pwmclk_init(); | ||
368 | } | ||