diff options
-rw-r--r-- | arch/arm/mach-omap2/Makefile | 3 | ||||
-rw-r--r-- | arch/arm/mach-omap2/clkt_dpll.c | 386 | ||||
-rw-r--r-- | arch/arm/mach-omap2/clock.c | 355 |
3 files changed, 388 insertions, 356 deletions
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile index 7d46fde2ce67..1a135c8e7f1e 100644 --- a/arch/arm/mach-omap2/Makefile +++ b/arch/arm/mach-omap2/Makefile | |||
@@ -8,7 +8,8 @@ obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer-gp.o | |||
8 | omap-2-3-common = irq.o sdrc.o omap_hwmod.o | 8 | omap-2-3-common = irq.o sdrc.o omap_hwmod.o |
9 | omap-3-4-common = dpll3xxx.o | 9 | omap-3-4-common = dpll3xxx.o |
10 | prcm-common = prcm.o powerdomain.o | 10 | prcm-common = prcm.o powerdomain.o |
11 | clock-common = clock.o clock_common_data.o clockdomain.o | 11 | clock-common = clock.o clock_common_data.o \ |
12 | clockdomain.o clkt_dpll.o | ||
12 | 13 | ||
13 | obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common) $(clock-common) | 14 | obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common) $(clock-common) |
14 | obj-$(CONFIG_ARCH_OMAP3) += $(omap-2-3-common) $(prcm-common) $(clock-common) \ | 15 | obj-$(CONFIG_ARCH_OMAP3) += $(omap-2-3-common) $(prcm-common) $(clock-common) \ |
diff --git a/arch/arm/mach-omap2/clkt_dpll.c b/arch/arm/mach-omap2/clkt_dpll.c new file mode 100644 index 000000000000..9eee0e67d5d6 --- /dev/null +++ b/arch/arm/mach-omap2/clkt_dpll.c | |||
@@ -0,0 +1,386 @@ | |||
1 | /* | ||
2 | * OMAP2/3/4 DPLL clock functions | ||
3 | * | ||
4 | * Copyright (C) 2005-2008 Texas Instruments, Inc. | ||
5 | * Copyright (C) 2004-2010 Nokia Corporation | ||
6 | * | ||
7 | * Contacts: | ||
8 | * Richard Woodruff <r-woodruff2@ti.com> | ||
9 | * Paul Walmsley | ||
10 | * | ||
11 | * This program is free software; you can redistribute it and/or modify | ||
12 | * it under the terms of the GNU General Public License version 2 as | ||
13 | * published by the Free Software Foundation. | ||
14 | */ | ||
15 | #undef DEBUG | ||
16 | |||
17 | #include <linux/kernel.h> | ||
18 | #include <linux/errno.h> | ||
19 | #include <linux/clk.h> | ||
20 | #include <linux/io.h> | ||
21 | |||
22 | #include <asm/div64.h> | ||
23 | |||
24 | #include <plat/clock.h> | ||
25 | |||
26 | #include "clock.h" | ||
27 | #include "cm.h" | ||
28 | #include "cm-regbits-24xx.h" | ||
29 | #include "cm-regbits-34xx.h" | ||
30 | |||
31 | /* DPLL rate rounding: minimum DPLL multiplier, divider values */ | ||
32 | #define DPLL_MIN_MULTIPLIER 1 | ||
33 | #define DPLL_MIN_DIVIDER 1 | ||
34 | |||
35 | /* Possible error results from _dpll_test_mult */ | ||
36 | #define DPLL_MULT_UNDERFLOW -1 | ||
37 | |||
38 | /* | ||
39 | * Scale factor to mitigate roundoff errors in DPLL rate rounding. | ||
40 | * The higher the scale factor, the greater the risk of arithmetic overflow, | ||
41 | * but the closer the rounded rate to the target rate. DPLL_SCALE_FACTOR | ||
42 | * must be a power of DPLL_SCALE_BASE. | ||
43 | */ | ||
44 | #define DPLL_SCALE_FACTOR 64 | ||
45 | #define DPLL_SCALE_BASE 2 | ||
46 | #define DPLL_ROUNDING_VAL ((DPLL_SCALE_BASE / 2) * \ | ||
47 | (DPLL_SCALE_FACTOR / DPLL_SCALE_BASE)) | ||
48 | |||
49 | /* DPLL valid Fint frequency band limits - from 34xx TRM Section 4.7.6.2 */ | ||
50 | #define DPLL_FINT_BAND1_MIN 750000 | ||
51 | #define DPLL_FINT_BAND1_MAX 2100000 | ||
52 | #define DPLL_FINT_BAND2_MIN 7500000 | ||
53 | #define DPLL_FINT_BAND2_MAX 21000000 | ||
54 | |||
55 | /* _dpll_test_fint() return codes */ | ||
56 | #define DPLL_FINT_UNDERFLOW -1 | ||
57 | #define DPLL_FINT_INVALID -2 | ||
58 | |||
59 | /* Private functions */ | ||
60 | |||
61 | /* | ||
62 | * _dpll_test_fint - test whether an Fint value is valid for the DPLL | ||
63 | * @clk: DPLL struct clk to test | ||
64 | * @n: divider value (N) to test | ||
65 | * | ||
66 | * Tests whether a particular divider @n will result in a valid DPLL | ||
67 | * internal clock frequency Fint. See the 34xx TRM 4.7.6.2 "DPLL Jitter | ||
68 | * Correction". Returns 0 if OK, -1 if the enclosing loop can terminate | ||
69 | * (assuming that it is counting N upwards), or -2 if the enclosing loop | ||
70 | * should skip to the next iteration (again assuming N is increasing). | ||
71 | */ | ||
72 | static int _dpll_test_fint(struct clk *clk, u8 n) | ||
73 | { | ||
74 | struct dpll_data *dd; | ||
75 | long fint; | ||
76 | int ret = 0; | ||
77 | |||
78 | dd = clk->dpll_data; | ||
79 | |||
80 | /* DPLL divider must result in a valid jitter correction val */ | ||
81 | fint = clk->parent->rate / (n + 1); | ||
82 | if (fint < DPLL_FINT_BAND1_MIN) { | ||
83 | |||
84 | pr_debug("rejecting n=%d due to Fint failure, " | ||
85 | "lowering max_divider\n", n); | ||
86 | dd->max_divider = n; | ||
87 | ret = DPLL_FINT_UNDERFLOW; | ||
88 | |||
89 | } else if (fint > DPLL_FINT_BAND1_MAX && | ||
90 | fint < DPLL_FINT_BAND2_MIN) { | ||
91 | |||
92 | pr_debug("rejecting n=%d due to Fint failure\n", n); | ||
93 | ret = DPLL_FINT_INVALID; | ||
94 | |||
95 | } else if (fint > DPLL_FINT_BAND2_MAX) { | ||
96 | |||
97 | pr_debug("rejecting n=%d due to Fint failure, " | ||
98 | "boosting min_divider\n", n); | ||
99 | dd->min_divider = n; | ||
100 | ret = DPLL_FINT_INVALID; | ||
101 | |||
102 | } | ||
103 | |||
104 | return ret; | ||
105 | } | ||
106 | |||
107 | static unsigned long _dpll_compute_new_rate(unsigned long parent_rate, | ||
108 | unsigned int m, unsigned int n) | ||
109 | { | ||
110 | unsigned long long num; | ||
111 | |||
112 | num = (unsigned long long)parent_rate * m; | ||
113 | do_div(num, n); | ||
114 | return num; | ||
115 | } | ||
116 | |||
117 | /* | ||
118 | * _dpll_test_mult - test a DPLL multiplier value | ||
119 | * @m: pointer to the DPLL m (multiplier) value under test | ||
120 | * @n: current DPLL n (divider) value under test | ||
121 | * @new_rate: pointer to storage for the resulting rounded rate | ||
122 | * @target_rate: the desired DPLL rate | ||
123 | * @parent_rate: the DPLL's parent clock rate | ||
124 | * | ||
125 | * This code tests a DPLL multiplier value, ensuring that the | ||
126 | * resulting rate will not be higher than the target_rate, and that | ||
127 | * the multiplier value itself is valid for the DPLL. Initially, the | ||
128 | * integer pointed to by the m argument should be prescaled by | ||
129 | * multiplying by DPLL_SCALE_FACTOR. The code will replace this with | ||
130 | * a non-scaled m upon return. This non-scaled m will result in a | ||
131 | * new_rate as close as possible to target_rate (but not greater than | ||
132 | * target_rate) given the current (parent_rate, n, prescaled m) | ||
133 | * triple. Returns DPLL_MULT_UNDERFLOW in the event that the | ||
134 | * non-scaled m attempted to underflow, which can allow the calling | ||
135 | * function to bail out early; or 0 upon success. | ||
136 | */ | ||
137 | static int _dpll_test_mult(int *m, int n, unsigned long *new_rate, | ||
138 | unsigned long target_rate, | ||
139 | unsigned long parent_rate) | ||
140 | { | ||
141 | int r = 0, carry = 0; | ||
142 | |||
143 | /* Unscale m and round if necessary */ | ||
144 | if (*m % DPLL_SCALE_FACTOR >= DPLL_ROUNDING_VAL) | ||
145 | carry = 1; | ||
146 | *m = (*m / DPLL_SCALE_FACTOR) + carry; | ||
147 | |||
148 | /* | ||
149 | * The new rate must be <= the target rate to avoid programming | ||
150 | * a rate that is impossible for the hardware to handle | ||
151 | */ | ||
152 | *new_rate = _dpll_compute_new_rate(parent_rate, *m, n); | ||
153 | if (*new_rate > target_rate) { | ||
154 | (*m)--; | ||
155 | *new_rate = 0; | ||
156 | } | ||
157 | |||
158 | /* Guard against m underflow */ | ||
159 | if (*m < DPLL_MIN_MULTIPLIER) { | ||
160 | *m = DPLL_MIN_MULTIPLIER; | ||
161 | *new_rate = 0; | ||
162 | r = DPLL_MULT_UNDERFLOW; | ||
163 | } | ||
164 | |||
165 | if (*new_rate == 0) | ||
166 | *new_rate = _dpll_compute_new_rate(parent_rate, *m, n); | ||
167 | |||
168 | return r; | ||
169 | } | ||
170 | |||
171 | /* Public functions */ | ||
172 | |||
173 | void omap2_init_dpll_parent(struct clk *clk) | ||
174 | { | ||
175 | u32 v; | ||
176 | struct dpll_data *dd; | ||
177 | |||
178 | dd = clk->dpll_data; | ||
179 | if (!dd) | ||
180 | return; | ||
181 | |||
182 | /* Return bypass rate if DPLL is bypassed */ | ||
183 | v = __raw_readl(dd->control_reg); | ||
184 | v &= dd->enable_mask; | ||
185 | v >>= __ffs(dd->enable_mask); | ||
186 | |||
187 | /* Reparent in case the dpll is in bypass */ | ||
188 | if (cpu_is_omap24xx()) { | ||
189 | if (v == OMAP2XXX_EN_DPLL_LPBYPASS || | ||
190 | v == OMAP2XXX_EN_DPLL_FRBYPASS) | ||
191 | clk_reparent(clk, dd->clk_bypass); | ||
192 | } else if (cpu_is_omap34xx()) { | ||
193 | if (v == OMAP3XXX_EN_DPLL_LPBYPASS || | ||
194 | v == OMAP3XXX_EN_DPLL_FRBYPASS) | ||
195 | clk_reparent(clk, dd->clk_bypass); | ||
196 | } else if (cpu_is_omap44xx()) { | ||
197 | if (v == OMAP4XXX_EN_DPLL_LPBYPASS || | ||
198 | v == OMAP4XXX_EN_DPLL_FRBYPASS || | ||
199 | v == OMAP4XXX_EN_DPLL_MNBYPASS) | ||
200 | clk_reparent(clk, dd->clk_bypass); | ||
201 | } | ||
202 | return; | ||
203 | } | ||
204 | |||
205 | /** | ||
206 | * omap2_get_dpll_rate - returns the current DPLL CLKOUT rate | ||
207 | * @clk: struct clk * of a DPLL | ||
208 | * | ||
209 | * DPLLs can be locked or bypassed - basically, enabled or disabled. | ||
210 | * When locked, the DPLL output depends on the M and N values. When | ||
211 | * bypassed, on OMAP2xxx, the output rate is either the 32KiHz clock | ||
212 | * or sys_clk. Bypass rates on OMAP3 depend on the DPLL: DPLLs 1 and | ||
213 | * 2 are bypassed with dpll1_fclk and dpll2_fclk respectively | ||
214 | * (generated by DPLL3), while DPLL 3, 4, and 5 bypass rates are sys_clk. | ||
215 | * Returns the current DPLL CLKOUT rate (*not* CLKOUTX2) if the DPLL is | ||
216 | * locked, or the appropriate bypass rate if the DPLL is bypassed, or 0 | ||
217 | * if the clock @clk is not a DPLL. | ||
218 | */ | ||
219 | u32 omap2_get_dpll_rate(struct clk *clk) | ||
220 | { | ||
221 | long long dpll_clk; | ||
222 | u32 dpll_mult, dpll_div, v; | ||
223 | struct dpll_data *dd; | ||
224 | |||
225 | dd = clk->dpll_data; | ||
226 | if (!dd) | ||
227 | return 0; | ||
228 | |||
229 | /* Return bypass rate if DPLL is bypassed */ | ||
230 | v = __raw_readl(dd->control_reg); | ||
231 | v &= dd->enable_mask; | ||
232 | v >>= __ffs(dd->enable_mask); | ||
233 | |||
234 | if (cpu_is_omap24xx()) { | ||
235 | if (v == OMAP2XXX_EN_DPLL_LPBYPASS || | ||
236 | v == OMAP2XXX_EN_DPLL_FRBYPASS) | ||
237 | return dd->clk_bypass->rate; | ||
238 | } else if (cpu_is_omap34xx()) { | ||
239 | if (v == OMAP3XXX_EN_DPLL_LPBYPASS || | ||
240 | v == OMAP3XXX_EN_DPLL_FRBYPASS) | ||
241 | return dd->clk_bypass->rate; | ||
242 | } else if (cpu_is_omap44xx()) { | ||
243 | if (v == OMAP4XXX_EN_DPLL_LPBYPASS || | ||
244 | v == OMAP4XXX_EN_DPLL_FRBYPASS || | ||
245 | v == OMAP4XXX_EN_DPLL_MNBYPASS) | ||
246 | return dd->clk_bypass->rate; | ||
247 | } | ||
248 | |||
249 | v = __raw_readl(dd->mult_div1_reg); | ||
250 | dpll_mult = v & dd->mult_mask; | ||
251 | dpll_mult >>= __ffs(dd->mult_mask); | ||
252 | dpll_div = v & dd->div1_mask; | ||
253 | dpll_div >>= __ffs(dd->div1_mask); | ||
254 | |||
255 | dpll_clk = (long long)dd->clk_ref->rate * dpll_mult; | ||
256 | do_div(dpll_clk, dpll_div + 1); | ||
257 | |||
258 | return dpll_clk; | ||
259 | } | ||
260 | |||
261 | /* DPLL rate rounding code */ | ||
262 | |||
263 | /** | ||
264 | * omap2_dpll_set_rate_tolerance: set the error tolerance during rate rounding | ||
265 | * @clk: struct clk * of the DPLL | ||
266 | * @tolerance: maximum rate error tolerance | ||
267 | * | ||
268 | * Set the maximum DPLL rate error tolerance for the rate rounding | ||
269 | * algorithm. The rate tolerance is an attempt to balance DPLL power | ||
270 | * saving (the least divider value "n") vs. rate fidelity (the least | ||
271 | * difference between the desired DPLL target rate and the rounded | ||
272 | * rate out of the algorithm). So, increasing the tolerance is likely | ||
273 | * to decrease DPLL power consumption and increase DPLL rate error. | ||
274 | * Returns -EINVAL if provided a null clock ptr or a clk that is not a | ||
275 | * DPLL; or 0 upon success. | ||
276 | */ | ||
277 | int omap2_dpll_set_rate_tolerance(struct clk *clk, unsigned int tolerance) | ||
278 | { | ||
279 | if (!clk || !clk->dpll_data) | ||
280 | return -EINVAL; | ||
281 | |||
282 | clk->dpll_data->rate_tolerance = tolerance; | ||
283 | |||
284 | return 0; | ||
285 | } | ||
286 | |||
287 | /** | ||
288 | * omap2_dpll_round_rate - round a target rate for an OMAP DPLL | ||
289 | * @clk: struct clk * for a DPLL | ||
290 | * @target_rate: desired DPLL clock rate | ||
291 | * | ||
292 | * Given a DPLL, a desired target rate, and a rate tolerance, round | ||
293 | * the target rate to a possible, programmable rate for this DPLL. | ||
294 | * Rate tolerance is assumed to be set by the caller before this | ||
295 | * function is called. Attempts to select the minimum possible n | ||
296 | * within the tolerance to reduce power consumption. Stores the | ||
297 | * computed (m, n) in the DPLL's dpll_data structure so set_rate() | ||
298 | * will not need to call this (expensive) function again. Returns ~0 | ||
299 | * if the target rate cannot be rounded, either because the rate is | ||
300 | * too low or because the rate tolerance is set too tightly; or the | ||
301 | * rounded rate upon success. | ||
302 | */ | ||
303 | long omap2_dpll_round_rate(struct clk *clk, unsigned long target_rate) | ||
304 | { | ||
305 | int m, n, r, e, scaled_max_m; | ||
306 | unsigned long scaled_rt_rp, new_rate; | ||
307 | int min_e = -1, min_e_m = -1, min_e_n = -1; | ||
308 | struct dpll_data *dd; | ||
309 | |||
310 | if (!clk || !clk->dpll_data) | ||
311 | return ~0; | ||
312 | |||
313 | dd = clk->dpll_data; | ||
314 | |||
315 | pr_debug("clock: starting DPLL round_rate for clock %s, target rate " | ||
316 | "%ld\n", clk->name, target_rate); | ||
317 | |||
318 | scaled_rt_rp = target_rate / (dd->clk_ref->rate / DPLL_SCALE_FACTOR); | ||
319 | scaled_max_m = dd->max_multiplier * DPLL_SCALE_FACTOR; | ||
320 | |||
321 | dd->last_rounded_rate = 0; | ||
322 | |||
323 | for (n = dd->min_divider; n <= dd->max_divider; n++) { | ||
324 | |||
325 | /* Is the (input clk, divider) pair valid for the DPLL? */ | ||
326 | r = _dpll_test_fint(clk, n); | ||
327 | if (r == DPLL_FINT_UNDERFLOW) | ||
328 | break; | ||
329 | else if (r == DPLL_FINT_INVALID) | ||
330 | continue; | ||
331 | |||
332 | /* Compute the scaled DPLL multiplier, based on the divider */ | ||
333 | m = scaled_rt_rp * n; | ||
334 | |||
335 | /* | ||
336 | * Since we're counting n up, a m overflow means we | ||
337 | * can bail out completely (since as n increases in | ||
338 | * the next iteration, there's no way that m can | ||
339 | * increase beyond the current m) | ||
340 | */ | ||
341 | if (m > scaled_max_m) | ||
342 | break; | ||
343 | |||
344 | r = _dpll_test_mult(&m, n, &new_rate, target_rate, | ||
345 | dd->clk_ref->rate); | ||
346 | |||
347 | /* m can't be set low enough for this n - try with a larger n */ | ||
348 | if (r == DPLL_MULT_UNDERFLOW) | ||
349 | continue; | ||
350 | |||
351 | e = target_rate - new_rate; | ||
352 | pr_debug("clock: n = %d: m = %d: rate error is %d " | ||
353 | "(new_rate = %ld)\n", n, m, e, new_rate); | ||
354 | |||
355 | if (min_e == -1 || | ||
356 | min_e >= (int)(abs(e) - dd->rate_tolerance)) { | ||
357 | min_e = e; | ||
358 | min_e_m = m; | ||
359 | min_e_n = n; | ||
360 | |||
361 | pr_debug("clock: found new least error %d\n", min_e); | ||
362 | |||
363 | /* We found good settings -- bail out now */ | ||
364 | if (min_e <= dd->rate_tolerance) | ||
365 | break; | ||
366 | } | ||
367 | } | ||
368 | |||
369 | if (min_e < 0) { | ||
370 | pr_debug("clock: error: target rate or tolerance too low\n"); | ||
371 | return ~0; | ||
372 | } | ||
373 | |||
374 | dd->last_rounded_m = min_e_m; | ||
375 | dd->last_rounded_n = min_e_n; | ||
376 | dd->last_rounded_rate = _dpll_compute_new_rate(dd->clk_ref->rate, | ||
377 | min_e_m, min_e_n); | ||
378 | |||
379 | pr_debug("clock: final least error: e = %d, m = %d, n = %d\n", | ||
380 | min_e, min_e_m, min_e_n); | ||
381 | pr_debug("clock: final rate: %ld (target rate: %ld)\n", | ||
382 | dd->last_rounded_rate, target_rate); | ||
383 | |||
384 | return dd->last_rounded_rate; | ||
385 | } | ||
386 | |||
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c index d88b25565a42..98196285e80c 100644 --- a/arch/arm/mach-omap2/clock.c +++ b/arch/arm/mach-omap2/clock.c | |||
@@ -28,10 +28,7 @@ | |||
28 | #include <plat/clockdomain.h> | 28 | #include <plat/clockdomain.h> |
29 | #include <plat/cpu.h> | 29 | #include <plat/cpu.h> |
30 | #include <plat/prcm.h> | 30 | #include <plat/prcm.h> |
31 | #include <asm/div64.h> | ||
32 | 31 | ||
33 | #include <plat/sdrc.h> | ||
34 | #include "sdrc.h" | ||
35 | #include "clock.h" | 32 | #include "clock.h" |
36 | #include "prm.h" | 33 | #include "prm.h" |
37 | #include "prm-regbits-24xx.h" | 34 | #include "prm-regbits-24xx.h" |
@@ -39,72 +36,12 @@ | |||
39 | #include "cm-regbits-24xx.h" | 36 | #include "cm-regbits-24xx.h" |
40 | #include "cm-regbits-34xx.h" | 37 | #include "cm-regbits-34xx.h" |
41 | 38 | ||
42 | /* DPLL rate rounding: minimum DPLL multiplier, divider values */ | ||
43 | #define DPLL_MIN_MULTIPLIER 1 | ||
44 | #define DPLL_MIN_DIVIDER 1 | ||
45 | |||
46 | /* Possible error results from _dpll_test_mult */ | ||
47 | #define DPLL_MULT_UNDERFLOW -1 | ||
48 | |||
49 | /* | ||
50 | * Scale factor to mitigate roundoff errors in DPLL rate rounding. | ||
51 | * The higher the scale factor, the greater the risk of arithmetic overflow, | ||
52 | * but the closer the rounded rate to the target rate. DPLL_SCALE_FACTOR | ||
53 | * must be a power of DPLL_SCALE_BASE. | ||
54 | */ | ||
55 | #define DPLL_SCALE_FACTOR 64 | ||
56 | #define DPLL_SCALE_BASE 2 | ||
57 | #define DPLL_ROUNDING_VAL ((DPLL_SCALE_BASE / 2) * \ | ||
58 | (DPLL_SCALE_FACTOR / DPLL_SCALE_BASE)) | ||
59 | |||
60 | /* DPLL valid Fint frequency band limits - from 34xx TRM Section 4.7.6.2 */ | ||
61 | #define DPLL_FINT_BAND1_MIN 750000 | ||
62 | #define DPLL_FINT_BAND1_MAX 2100000 | ||
63 | #define DPLL_FINT_BAND2_MIN 7500000 | ||
64 | #define DPLL_FINT_BAND2_MAX 21000000 | ||
65 | |||
66 | /* _dpll_test_fint() return codes */ | ||
67 | #define DPLL_FINT_UNDERFLOW -1 | ||
68 | #define DPLL_FINT_INVALID -2 | ||
69 | |||
70 | u8 cpu_mask; | 39 | u8 cpu_mask; |
71 | 40 | ||
72 | /*------------------------------------------------------------------------- | 41 | /*------------------------------------------------------------------------- |
73 | * OMAP2/3/4 specific clock functions | 42 | * OMAP2/3/4 specific clock functions |
74 | *-------------------------------------------------------------------------*/ | 43 | *-------------------------------------------------------------------------*/ |
75 | 44 | ||
76 | void omap2_init_dpll_parent(struct clk *clk) | ||
77 | { | ||
78 | u32 v; | ||
79 | struct dpll_data *dd; | ||
80 | |||
81 | dd = clk->dpll_data; | ||
82 | if (!dd) | ||
83 | return; | ||
84 | |||
85 | /* Return bypass rate if DPLL is bypassed */ | ||
86 | v = __raw_readl(dd->control_reg); | ||
87 | v &= dd->enable_mask; | ||
88 | v >>= __ffs(dd->enable_mask); | ||
89 | |||
90 | /* Reparent in case the dpll is in bypass */ | ||
91 | if (cpu_is_omap24xx()) { | ||
92 | if (v == OMAP2XXX_EN_DPLL_LPBYPASS || | ||
93 | v == OMAP2XXX_EN_DPLL_FRBYPASS) | ||
94 | clk_reparent(clk, dd->clk_bypass); | ||
95 | } else if (cpu_is_omap34xx()) { | ||
96 | if (v == OMAP3XXX_EN_DPLL_LPBYPASS || | ||
97 | v == OMAP3XXX_EN_DPLL_FRBYPASS) | ||
98 | clk_reparent(clk, dd->clk_bypass); | ||
99 | } else if (cpu_is_omap44xx()) { | ||
100 | if (v == OMAP4XXX_EN_DPLL_LPBYPASS || | ||
101 | v == OMAP4XXX_EN_DPLL_FRBYPASS || | ||
102 | v == OMAP4XXX_EN_DPLL_MNBYPASS) | ||
103 | clk_reparent(clk, dd->clk_bypass); | ||
104 | } | ||
105 | return; | ||
106 | } | ||
107 | |||
108 | /** | 45 | /** |
109 | * _omap2xxx_clk_commit - commit clock parent/rate changes in hardware | 46 | * _omap2xxx_clk_commit - commit clock parent/rate changes in hardware |
110 | * @clk: struct clk * | 47 | * @clk: struct clk * |
@@ -127,52 +64,6 @@ static void _omap2xxx_clk_commit(struct clk *clk) | |||
127 | prm_read_mod_reg(OMAP24XX_GR_MOD, OMAP2_PRCM_CLKCFG_CTRL_OFFSET); | 64 | prm_read_mod_reg(OMAP24XX_GR_MOD, OMAP2_PRCM_CLKCFG_CTRL_OFFSET); |
128 | } | 65 | } |
129 | 66 | ||
130 | /* | ||
131 | * _dpll_test_fint - test whether an Fint value is valid for the DPLL | ||
132 | * @clk: DPLL struct clk to test | ||
133 | * @n: divider value (N) to test | ||
134 | * | ||
135 | * Tests whether a particular divider @n will result in a valid DPLL | ||
136 | * internal clock frequency Fint. See the 34xx TRM 4.7.6.2 "DPLL Jitter | ||
137 | * Correction". Returns 0 if OK, -1 if the enclosing loop can terminate | ||
138 | * (assuming that it is counting N upwards), or -2 if the enclosing loop | ||
139 | * should skip to the next iteration (again assuming N is increasing). | ||
140 | */ | ||
141 | static int _dpll_test_fint(struct clk *clk, u8 n) | ||
142 | { | ||
143 | struct dpll_data *dd; | ||
144 | long fint; | ||
145 | int ret = 0; | ||
146 | |||
147 | dd = clk->dpll_data; | ||
148 | |||
149 | /* DPLL divider must result in a valid jitter correction val */ | ||
150 | fint = clk->parent->rate / (n + 1); | ||
151 | if (fint < DPLL_FINT_BAND1_MIN) { | ||
152 | |||
153 | pr_debug("rejecting n=%d due to Fint failure, " | ||
154 | "lowering max_divider\n", n); | ||
155 | dd->max_divider = n; | ||
156 | ret = DPLL_FINT_UNDERFLOW; | ||
157 | |||
158 | } else if (fint > DPLL_FINT_BAND1_MAX && | ||
159 | fint < DPLL_FINT_BAND2_MIN) { | ||
160 | |||
161 | pr_debug("rejecting n=%d due to Fint failure\n", n); | ||
162 | ret = DPLL_FINT_INVALID; | ||
163 | |||
164 | } else if (fint > DPLL_FINT_BAND2_MAX) { | ||
165 | |||
166 | pr_debug("rejecting n=%d due to Fint failure, " | ||
167 | "boosting min_divider\n", n); | ||
168 | dd->min_divider = n; | ||
169 | ret = DPLL_FINT_INVALID; | ||
170 | |||
171 | } | ||
172 | |||
173 | return ret; | ||
174 | } | ||
175 | |||
176 | /** | 67 | /** |
177 | * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk | 68 | * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk |
178 | * @clk: OMAP clock struct ptr to use | 69 | * @clk: OMAP clock struct ptr to use |
@@ -243,62 +134,6 @@ void omap2_init_clksel_parent(struct clk *clk) | |||
243 | } | 134 | } |
244 | 135 | ||
245 | /** | 136 | /** |
246 | * omap2_get_dpll_rate - returns the current DPLL CLKOUT rate | ||
247 | * @clk: struct clk * of a DPLL | ||
248 | * | ||
249 | * DPLLs can be locked or bypassed - basically, enabled or disabled. | ||
250 | * When locked, the DPLL output depends on the M and N values. When | ||
251 | * bypassed, on OMAP2xxx, the output rate is either the 32KiHz clock | ||
252 | * or sys_clk. Bypass rates on OMAP3 depend on the DPLL: DPLLs 1 and | ||
253 | * 2 are bypassed with dpll1_fclk and dpll2_fclk respectively | ||
254 | * (generated by DPLL3), while DPLL 3, 4, and 5 bypass rates are sys_clk. | ||
255 | * Returns the current DPLL CLKOUT rate (*not* CLKOUTX2) if the DPLL is | ||
256 | * locked, or the appropriate bypass rate if the DPLL is bypassed, or 0 | ||
257 | * if the clock @clk is not a DPLL. | ||
258 | */ | ||
259 | u32 omap2_get_dpll_rate(struct clk *clk) | ||
260 | { | ||
261 | long long dpll_clk; | ||
262 | u32 dpll_mult, dpll_div, v; | ||
263 | struct dpll_data *dd; | ||
264 | |||
265 | dd = clk->dpll_data; | ||
266 | if (!dd) | ||
267 | return 0; | ||
268 | |||
269 | /* Return bypass rate if DPLL is bypassed */ | ||
270 | v = __raw_readl(dd->control_reg); | ||
271 | v &= dd->enable_mask; | ||
272 | v >>= __ffs(dd->enable_mask); | ||
273 | |||
274 | if (cpu_is_omap24xx()) { | ||
275 | if (v == OMAP2XXX_EN_DPLL_LPBYPASS || | ||
276 | v == OMAP2XXX_EN_DPLL_FRBYPASS) | ||
277 | return dd->clk_bypass->rate; | ||
278 | } else if (cpu_is_omap34xx()) { | ||
279 | if (v == OMAP3XXX_EN_DPLL_LPBYPASS || | ||
280 | v == OMAP3XXX_EN_DPLL_FRBYPASS) | ||
281 | return dd->clk_bypass->rate; | ||
282 | } else if (cpu_is_omap44xx()) { | ||
283 | if (v == OMAP4XXX_EN_DPLL_LPBYPASS || | ||
284 | v == OMAP4XXX_EN_DPLL_FRBYPASS || | ||
285 | v == OMAP4XXX_EN_DPLL_MNBYPASS) | ||
286 | return dd->clk_bypass->rate; | ||
287 | } | ||
288 | |||
289 | v = __raw_readl(dd->mult_div1_reg); | ||
290 | dpll_mult = v & dd->mult_mask; | ||
291 | dpll_mult >>= __ffs(dd->mult_mask); | ||
292 | dpll_div = v & dd->div1_mask; | ||
293 | dpll_div >>= __ffs(dd->div1_mask); | ||
294 | |||
295 | dpll_clk = (long long)dd->clk_ref->rate * dpll_mult; | ||
296 | do_div(dpll_clk, dpll_div + 1); | ||
297 | |||
298 | return dpll_clk; | ||
299 | } | ||
300 | |||
301 | /** | ||
302 | * omap2_clk_dflt_find_companion - find companion clock to @clk | 137 | * omap2_clk_dflt_find_companion - find companion clock to @clk |
303 | * @clk: struct clk * to find the companion clock of | 138 | * @clk: struct clk * to find the companion clock of |
304 | * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in | 139 | * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in |
@@ -858,196 +693,6 @@ int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent) | |||
858 | return 0; | 693 | return 0; |
859 | } | 694 | } |
860 | 695 | ||
861 | /* DPLL rate rounding code */ | ||
862 | |||
863 | /** | ||
864 | * omap2_dpll_set_rate_tolerance: set the error tolerance during rate rounding | ||
865 | * @clk: struct clk * of the DPLL | ||
866 | * @tolerance: maximum rate error tolerance | ||
867 | * | ||
868 | * Set the maximum DPLL rate error tolerance for the rate rounding | ||
869 | * algorithm. The rate tolerance is an attempt to balance DPLL power | ||
870 | * saving (the least divider value "n") vs. rate fidelity (the least | ||
871 | * difference between the desired DPLL target rate and the rounded | ||
872 | * rate out of the algorithm). So, increasing the tolerance is likely | ||
873 | * to decrease DPLL power consumption and increase DPLL rate error. | ||
874 | * Returns -EINVAL if provided a null clock ptr or a clk that is not a | ||
875 | * DPLL; or 0 upon success. | ||
876 | */ | ||
877 | int omap2_dpll_set_rate_tolerance(struct clk *clk, unsigned int tolerance) | ||
878 | { | ||
879 | if (!clk || !clk->dpll_data) | ||
880 | return -EINVAL; | ||
881 | |||
882 | clk->dpll_data->rate_tolerance = tolerance; | ||
883 | |||
884 | return 0; | ||
885 | } | ||
886 | |||
887 | static unsigned long _dpll_compute_new_rate(unsigned long parent_rate, | ||
888 | unsigned int m, unsigned int n) | ||
889 | { | ||
890 | unsigned long long num; | ||
891 | |||
892 | num = (unsigned long long)parent_rate * m; | ||
893 | do_div(num, n); | ||
894 | return num; | ||
895 | } | ||
896 | |||
897 | /* | ||
898 | * _dpll_test_mult - test a DPLL multiplier value | ||
899 | * @m: pointer to the DPLL m (multiplier) value under test | ||
900 | * @n: current DPLL n (divider) value under test | ||
901 | * @new_rate: pointer to storage for the resulting rounded rate | ||
902 | * @target_rate: the desired DPLL rate | ||
903 | * @parent_rate: the DPLL's parent clock rate | ||
904 | * | ||
905 | * This code tests a DPLL multiplier value, ensuring that the | ||
906 | * resulting rate will not be higher than the target_rate, and that | ||
907 | * the multiplier value itself is valid for the DPLL. Initially, the | ||
908 | * integer pointed to by the m argument should be prescaled by | ||
909 | * multiplying by DPLL_SCALE_FACTOR. The code will replace this with | ||
910 | * a non-scaled m upon return. This non-scaled m will result in a | ||
911 | * new_rate as close as possible to target_rate (but not greater than | ||
912 | * target_rate) given the current (parent_rate, n, prescaled m) | ||
913 | * triple. Returns DPLL_MULT_UNDERFLOW in the event that the | ||
914 | * non-scaled m attempted to underflow, which can allow the calling | ||
915 | * function to bail out early; or 0 upon success. | ||
916 | */ | ||
917 | static int _dpll_test_mult(int *m, int n, unsigned long *new_rate, | ||
918 | unsigned long target_rate, | ||
919 | unsigned long parent_rate) | ||
920 | { | ||
921 | int r = 0, carry = 0; | ||
922 | |||
923 | /* Unscale m and round if necessary */ | ||
924 | if (*m % DPLL_SCALE_FACTOR >= DPLL_ROUNDING_VAL) | ||
925 | carry = 1; | ||
926 | *m = (*m / DPLL_SCALE_FACTOR) + carry; | ||
927 | |||
928 | /* | ||
929 | * The new rate must be <= the target rate to avoid programming | ||
930 | * a rate that is impossible for the hardware to handle | ||
931 | */ | ||
932 | *new_rate = _dpll_compute_new_rate(parent_rate, *m, n); | ||
933 | if (*new_rate > target_rate) { | ||
934 | (*m)--; | ||
935 | *new_rate = 0; | ||
936 | } | ||
937 | |||
938 | /* Guard against m underflow */ | ||
939 | if (*m < DPLL_MIN_MULTIPLIER) { | ||
940 | *m = DPLL_MIN_MULTIPLIER; | ||
941 | *new_rate = 0; | ||
942 | r = DPLL_MULT_UNDERFLOW; | ||
943 | } | ||
944 | |||
945 | if (*new_rate == 0) | ||
946 | *new_rate = _dpll_compute_new_rate(parent_rate, *m, n); | ||
947 | |||
948 | return r; | ||
949 | } | ||
950 | |||
951 | /** | ||
952 | * omap2_dpll_round_rate - round a target rate for an OMAP DPLL | ||
953 | * @clk: struct clk * for a DPLL | ||
954 | * @target_rate: desired DPLL clock rate | ||
955 | * | ||
956 | * Given a DPLL, a desired target rate, and a rate tolerance, round | ||
957 | * the target rate to a possible, programmable rate for this DPLL. | ||
958 | * Rate tolerance is assumed to be set by the caller before this | ||
959 | * function is called. Attempts to select the minimum possible n | ||
960 | * within the tolerance to reduce power consumption. Stores the | ||
961 | * computed (m, n) in the DPLL's dpll_data structure so set_rate() | ||
962 | * will not need to call this (expensive) function again. Returns ~0 | ||
963 | * if the target rate cannot be rounded, either because the rate is | ||
964 | * too low or because the rate tolerance is set too tightly; or the | ||
965 | * rounded rate upon success. | ||
966 | */ | ||
967 | long omap2_dpll_round_rate(struct clk *clk, unsigned long target_rate) | ||
968 | { | ||
969 | int m, n, r, e, scaled_max_m; | ||
970 | unsigned long scaled_rt_rp, new_rate; | ||
971 | int min_e = -1, min_e_m = -1, min_e_n = -1; | ||
972 | struct dpll_data *dd; | ||
973 | |||
974 | if (!clk || !clk->dpll_data) | ||
975 | return ~0; | ||
976 | |||
977 | dd = clk->dpll_data; | ||
978 | |||
979 | pr_debug("clock: starting DPLL round_rate for clock %s, target rate " | ||
980 | "%ld\n", clk->name, target_rate); | ||
981 | |||
982 | scaled_rt_rp = target_rate / (dd->clk_ref->rate / DPLL_SCALE_FACTOR); | ||
983 | scaled_max_m = dd->max_multiplier * DPLL_SCALE_FACTOR; | ||
984 | |||
985 | dd->last_rounded_rate = 0; | ||
986 | |||
987 | for (n = dd->min_divider; n <= dd->max_divider; n++) { | ||
988 | |||
989 | /* Is the (input clk, divider) pair valid for the DPLL? */ | ||
990 | r = _dpll_test_fint(clk, n); | ||
991 | if (r == DPLL_FINT_UNDERFLOW) | ||
992 | break; | ||
993 | else if (r == DPLL_FINT_INVALID) | ||
994 | continue; | ||
995 | |||
996 | /* Compute the scaled DPLL multiplier, based on the divider */ | ||
997 | m = scaled_rt_rp * n; | ||
998 | |||
999 | /* | ||
1000 | * Since we're counting n up, a m overflow means we | ||
1001 | * can bail out completely (since as n increases in | ||
1002 | * the next iteration, there's no way that m can | ||
1003 | * increase beyond the current m) | ||
1004 | */ | ||
1005 | if (m > scaled_max_m) | ||
1006 | break; | ||
1007 | |||
1008 | r = _dpll_test_mult(&m, n, &new_rate, target_rate, | ||
1009 | dd->clk_ref->rate); | ||
1010 | |||
1011 | /* m can't be set low enough for this n - try with a larger n */ | ||
1012 | if (r == DPLL_MULT_UNDERFLOW) | ||
1013 | continue; | ||
1014 | |||
1015 | e = target_rate - new_rate; | ||
1016 | pr_debug("clock: n = %d: m = %d: rate error is %d " | ||
1017 | "(new_rate = %ld)\n", n, m, e, new_rate); | ||
1018 | |||
1019 | if (min_e == -1 || | ||
1020 | min_e >= (int)(abs(e) - dd->rate_tolerance)) { | ||
1021 | min_e = e; | ||
1022 | min_e_m = m; | ||
1023 | min_e_n = n; | ||
1024 | |||
1025 | pr_debug("clock: found new least error %d\n", min_e); | ||
1026 | |||
1027 | /* We found good settings -- bail out now */ | ||
1028 | if (min_e <= dd->rate_tolerance) | ||
1029 | break; | ||
1030 | } | ||
1031 | } | ||
1032 | |||
1033 | if (min_e < 0) { | ||
1034 | pr_debug("clock: error: target rate or tolerance too low\n"); | ||
1035 | return ~0; | ||
1036 | } | ||
1037 | |||
1038 | dd->last_rounded_m = min_e_m; | ||
1039 | dd->last_rounded_n = min_e_n; | ||
1040 | dd->last_rounded_rate = _dpll_compute_new_rate(dd->clk_ref->rate, | ||
1041 | min_e_m, min_e_n); | ||
1042 | |||
1043 | pr_debug("clock: final least error: e = %d, m = %d, n = %d\n", | ||
1044 | min_e, min_e_m, min_e_n); | ||
1045 | pr_debug("clock: final rate: %ld (target rate: %ld)\n", | ||
1046 | dd->last_rounded_rate, target_rate); | ||
1047 | |||
1048 | return dd->last_rounded_rate; | ||
1049 | } | ||
1050 | |||
1051 | /*------------------------------------------------------------------------- | 696 | /*------------------------------------------------------------------------- |
1052 | * Omap2 clock reset and init functions | 697 | * Omap2 clock reset and init functions |
1053 | *-------------------------------------------------------------------------*/ | 698 | *-------------------------------------------------------------------------*/ |