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35e424e2 PW |
1 | /* |
2 | * OMAP34xx M2 divider clock code | |
3 | * | |
4 | * Copyright (C) 2007-2008 Texas Instruments, Inc. | |
5 | * Copyright (C) 2007-2010 Nokia Corporation | |
6 | * | |
7 | * Paul Walmsley | |
8 | * Jouni Högander | |
9 | * | |
10 | * Parts of this code are based on code written by | |
11 | * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
16 | */ | |
17 | #undef DEBUG | |
18 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/errno.h> | |
21 | #include <linux/clk.h> | |
22 | #include <linux/io.h> | |
23 | ||
24 | #include <plat/clock.h> | |
25 | #include <plat/sram.h> | |
26 | #include <plat/sdrc.h> | |
27 | ||
28 | #include "clock.h" | |
657ebfad | 29 | #include "clock3xxx.h" |
35e424e2 PW |
30 | #include "clock34xx.h" |
31 | #include "sdrc.h" | |
32 | ||
33 | #define CYCLES_PER_MHZ 1000000 | |
34 | ||
35 | /* | |
36 | * CORE DPLL (DPLL3) M2 divider rate programming functions | |
37 | * | |
38 | * These call into SRAM code to do the actual CM writes, since the SDRAM | |
39 | * is clocked from DPLL3. | |
40 | */ | |
41 | ||
42 | /** | |
43 | * omap3_core_dpll_m2_set_rate - set CORE DPLL M2 divider | |
44 | * @clk: struct clk * of DPLL to set | |
45 | * @rate: rounded target rate | |
46 | * | |
47 | * Program the DPLL M2 divider with the rounded target rate. Returns | |
48 | * -EINVAL upon error, or 0 upon success. | |
49 | */ | |
50 | int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate) | |
51 | { | |
52 | u32 new_div = 0; | |
53 | u32 unlock_dll = 0; | |
54 | u32 c; | |
55 | unsigned long validrate, sdrcrate, _mpurate; | |
56 | struct omap_sdrc_params *sdrc_cs0; | |
57 | struct omap_sdrc_params *sdrc_cs1; | |
58 | int ret; | |
59 | ||
60 | if (!clk || !rate) | |
61 | return -EINVAL; | |
62 | ||
63 | validrate = omap2_clksel_round_rate_div(clk, rate, &new_div); | |
64 | if (validrate != rate) | |
65 | return -EINVAL; | |
66 | ||
67 | sdrcrate = sdrc_ick_p->rate; | |
68 | if (rate > clk->rate) | |
69 | sdrcrate <<= ((rate / clk->rate) >> 1); | |
70 | else | |
71 | sdrcrate >>= ((clk->rate / rate) >> 1); | |
72 | ||
73 | ret = omap2_sdrc_get_params(sdrcrate, &sdrc_cs0, &sdrc_cs1); | |
74 | if (ret) | |
75 | return -EINVAL; | |
76 | ||
77 | if (sdrcrate < MIN_SDRC_DLL_LOCK_FREQ) { | |
78 | pr_debug("clock: will unlock SDRC DLL\n"); | |
79 | unlock_dll = 1; | |
80 | } | |
81 | ||
82 | /* | |
83 | * XXX This only needs to be done when the CPU frequency changes | |
84 | */ | |
85 | _mpurate = arm_fck_p->rate / CYCLES_PER_MHZ; | |
86 | c = (_mpurate << SDRC_MPURATE_SCALE) >> SDRC_MPURATE_BASE_SHIFT; | |
87 | c += 1; /* for safety */ | |
88 | c *= SDRC_MPURATE_LOOPS; | |
89 | c >>= SDRC_MPURATE_SCALE; | |
90 | if (c == 0) | |
91 | c = 1; | |
92 | ||
93 | pr_debug("clock: changing CORE DPLL rate from %lu to %lu\n", clk->rate, | |
94 | validrate); | |
95 | pr_debug("clock: SDRC CS0 timing params used:" | |
96 | " RFR %08x CTRLA %08x CTRLB %08x MR %08x\n", | |
97 | sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla, | |
98 | sdrc_cs0->actim_ctrlb, sdrc_cs0->mr); | |
99 | if (sdrc_cs1) | |
100 | pr_debug("clock: SDRC CS1 timing params used: " | |
101 | " RFR %08x CTRLA %08x CTRLB %08x MR %08x\n", | |
102 | sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla, | |
103 | sdrc_cs1->actim_ctrlb, sdrc_cs1->mr); | |
104 | ||
105 | if (sdrc_cs1) | |
106 | omap3_configure_core_dpll( | |
107 | new_div, unlock_dll, c, rate > clk->rate, | |
108 | sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla, | |
109 | sdrc_cs0->actim_ctrlb, sdrc_cs0->mr, | |
110 | sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla, | |
111 | sdrc_cs1->actim_ctrlb, sdrc_cs1->mr); | |
112 | else | |
113 | omap3_configure_core_dpll( | |
114 | new_div, unlock_dll, c, rate > clk->rate, | |
115 | sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla, | |
116 | sdrc_cs0->actim_ctrlb, sdrc_cs0->mr, | |
117 | 0, 0, 0, 0); | |
5fd2a84a | 118 | clk->rate = rate; |
35e424e2 PW |
119 | |
120 | return 0; | |
121 | } | |
122 |