1 /* $NetBSD: meson_clk_mpll.c,v 1.2 2019/02/25 19:30:17 jmcneill Exp $ */
2
3 /*-
4 * Copyright (c) 2019 Jared McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: meson_clk_mpll.c,v 1.2 2019/02/25 19:30:17 jmcneill Exp $");
31
32 #include <sys/param.h>
33 #include <sys/bus.h>
34
35 #include <dev/clk/clk_backend.h>
36
37 #include <arm/amlogic/meson_clk.h>
38
39 #define SDM_DEN 0x4000
40
41 u_int
meson_clk_mpll_get_rate(struct meson_clk_softc * sc,struct meson_clk_clk * clk)42 meson_clk_mpll_get_rate(struct meson_clk_softc *sc,
43 struct meson_clk_clk *clk)
44 {
45 struct meson_clk_mpll *mpll = &clk->u.mpll;
46 struct clk *clkp, *clkp_parent;
47 uint64_t parent_rate, sdm, n2;
48 uint32_t val;
49
50 KASSERT(clk->type == MESON_CLK_MPLL);
51
52 clkp = &clk->base;
53 clkp_parent = clk_get_parent(clkp);
54 if (clkp_parent == NULL)
55 return 0;
56
57 parent_rate = clk_get_rate(clkp_parent);
58 if (parent_rate == 0)
59 return 0;
60
61 CLK_LOCK(sc);
62
63 val = CLK_READ(sc, mpll->sdm.reg);
64 sdm = __SHIFTOUT(val, mpll->sdm.mask);
65
66 val = CLK_READ(sc, mpll->n2.reg);
67 n2 = __SHIFTOUT(val, mpll->n2.mask);
68
69 CLK_UNLOCK(sc);
70
71 const uint64_t div = (SDM_DEN * n2) + sdm;
72 if (div == 0)
73 return 0;
74
75 return (u_int)howmany(parent_rate * SDM_DEN, div);
76 }
77
78 const char *
meson_clk_mpll_get_parent(struct meson_clk_softc * sc,struct meson_clk_clk * clk)79 meson_clk_mpll_get_parent(struct meson_clk_softc *sc,
80 struct meson_clk_clk *clk)
81 {
82 struct meson_clk_mpll *mpll = &clk->u.mpll;
83
84 KASSERT(clk->type == MESON_CLK_MPLL);
85
86 return mpll->parent;
87 }
88