1*8afae5d5Sryo /* $NetBSD: meson_clk_pll.c,v 1.3 2021/01/01 07:21:58 ryo Exp $ */
2912cfa14Sjmcneill
3912cfa14Sjmcneill /*-
4912cfa14Sjmcneill * Copyright (c) 2019 Jared McNeill <jmcneill@invisible.ca>
5912cfa14Sjmcneill * All rights reserved.
6912cfa14Sjmcneill *
7912cfa14Sjmcneill * Redistribution and use in source and binary forms, with or without
8912cfa14Sjmcneill * modification, are permitted provided that the following conditions
9912cfa14Sjmcneill * are met:
10912cfa14Sjmcneill * 1. Redistributions of source code must retain the above copyright
11912cfa14Sjmcneill * notice, this list of conditions and the following disclaimer.
12912cfa14Sjmcneill * 2. Redistributions in binary form must reproduce the above copyright
13912cfa14Sjmcneill * notice, this list of conditions and the following disclaimer in the
14912cfa14Sjmcneill * documentation and/or other materials provided with the distribution.
15912cfa14Sjmcneill *
16912cfa14Sjmcneill * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17912cfa14Sjmcneill * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18912cfa14Sjmcneill * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19912cfa14Sjmcneill * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20912cfa14Sjmcneill * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21912cfa14Sjmcneill * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22912cfa14Sjmcneill * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23912cfa14Sjmcneill * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24912cfa14Sjmcneill * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25912cfa14Sjmcneill * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26912cfa14Sjmcneill * SUCH DAMAGE.
27912cfa14Sjmcneill */
28912cfa14Sjmcneill
29912cfa14Sjmcneill #include <sys/cdefs.h>
30*8afae5d5Sryo __KERNEL_RCSID(0, "$NetBSD: meson_clk_pll.c,v 1.3 2021/01/01 07:21:58 ryo Exp $");
31912cfa14Sjmcneill
32912cfa14Sjmcneill #include <sys/param.h>
33912cfa14Sjmcneill #include <sys/bus.h>
34912cfa14Sjmcneill
35912cfa14Sjmcneill #include <dev/clk/clk_backend.h>
36912cfa14Sjmcneill
37912cfa14Sjmcneill #include <arm/amlogic/meson_clk.h>
38912cfa14Sjmcneill
39912cfa14Sjmcneill u_int
meson_clk_pll_get_rate(struct meson_clk_softc * sc,struct meson_clk_clk * clk)40912cfa14Sjmcneill meson_clk_pll_get_rate(struct meson_clk_softc *sc,
41912cfa14Sjmcneill struct meson_clk_clk *clk)
42912cfa14Sjmcneill {
43912cfa14Sjmcneill struct meson_clk_pll *pll = &clk->u.pll;
44912cfa14Sjmcneill struct clk *clkp, *clkp_parent;
45912cfa14Sjmcneill u_int n, m, frac;
46912cfa14Sjmcneill uint64_t parent_rate, rate;
47912cfa14Sjmcneill uint32_t val;
48912cfa14Sjmcneill
49912cfa14Sjmcneill KASSERT(clk->type == MESON_CLK_PLL);
50912cfa14Sjmcneill
51912cfa14Sjmcneill clkp = &clk->base;
52912cfa14Sjmcneill clkp_parent = clk_get_parent(clkp);
53912cfa14Sjmcneill if (clkp_parent == NULL)
54912cfa14Sjmcneill return 0;
55912cfa14Sjmcneill
56912cfa14Sjmcneill parent_rate = clk_get_rate(clkp_parent);
57912cfa14Sjmcneill if (parent_rate == 0)
58912cfa14Sjmcneill return 0;
59912cfa14Sjmcneill
607e38c880Sjmcneill CLK_LOCK(sc);
617e38c880Sjmcneill
62912cfa14Sjmcneill val = CLK_READ(sc, pll->n.reg);
63912cfa14Sjmcneill n = __SHIFTOUT(val, pll->n.mask);
64912cfa14Sjmcneill
65912cfa14Sjmcneill val = CLK_READ(sc, pll->m.reg);
66912cfa14Sjmcneill m = __SHIFTOUT(val, pll->m.mask);
67912cfa14Sjmcneill
68912cfa14Sjmcneill if (pll->frac.mask) {
69912cfa14Sjmcneill val = CLK_READ(sc, pll->frac.reg);
70912cfa14Sjmcneill frac = __SHIFTOUT(val, pll->frac.mask);
71912cfa14Sjmcneill } else {
72912cfa14Sjmcneill frac = 0;
73912cfa14Sjmcneill }
74912cfa14Sjmcneill
757e38c880Sjmcneill CLK_UNLOCK(sc);
767e38c880Sjmcneill
77912cfa14Sjmcneill rate = parent_rate * m;
78912cfa14Sjmcneill if (frac) {
79912cfa14Sjmcneill uint64_t frac_rate = parent_rate * frac;
80912cfa14Sjmcneill rate += howmany(frac_rate, __SHIFTOUT_MASK(pll->frac.mask) + 1);
81912cfa14Sjmcneill }
82912cfa14Sjmcneill
83912cfa14Sjmcneill return (u_int)howmany(rate, n);
84912cfa14Sjmcneill }
85912cfa14Sjmcneill
86*8afae5d5Sryo /* the lock must have been acquired with CLK_LOCK() */
87*8afae5d5Sryo int
meson_clk_pll_wait_lock(struct meson_clk_softc * sc,struct meson_clk_pll * pll)88*8afae5d5Sryo meson_clk_pll_wait_lock(struct meson_clk_softc *sc, struct meson_clk_pll *pll)
89*8afae5d5Sryo {
90*8afae5d5Sryo int i;
91*8afae5d5Sryo for (i = 24000000; i > 0; i--) {
92*8afae5d5Sryo if ((CLK_READ(sc, pll->l.reg) & pll->l.mask) != 0)
93*8afae5d5Sryo return 0;
94*8afae5d5Sryo }
95*8afae5d5Sryo return ETIMEDOUT;
96*8afae5d5Sryo }
97*8afae5d5Sryo
98*8afae5d5Sryo int
meson_clk_pll_set_rate(struct meson_clk_softc * sc,struct meson_clk_clk * clk,u_int new_rate)99*8afae5d5Sryo meson_clk_pll_set_rate(struct meson_clk_softc *sc, struct meson_clk_clk *clk,
100*8afae5d5Sryo u_int new_rate)
101*8afae5d5Sryo {
102*8afae5d5Sryo struct meson_clk_pll *pll = &clk->u.pll;
103*8afae5d5Sryo struct clk *clkp, *clkp_parent;
104*8afae5d5Sryo uint64_t parent_rate, tmp;
105*8afae5d5Sryo uint32_t n, m, m_max, frac, frac_max;
106*8afae5d5Sryo int error;
107*8afae5d5Sryo
108*8afae5d5Sryo KASSERT(clk->type == MESON_CLK_PLL);
109*8afae5d5Sryo
110*8afae5d5Sryo clkp = &clk->base;
111*8afae5d5Sryo clkp_parent = clk_get_parent(clkp);
112*8afae5d5Sryo if (clkp_parent == NULL)
113*8afae5d5Sryo return ENXIO;
114*8afae5d5Sryo
115*8afae5d5Sryo if ((pll->flags & MESON_CLK_DIV_SET_RATE_PARENT) != 0)
116*8afae5d5Sryo return clk_set_rate(clkp_parent, new_rate);
117*8afae5d5Sryo
118*8afae5d5Sryo parent_rate = clk_get_rate(clkp_parent);
119*8afae5d5Sryo if (parent_rate == 0) {
120*8afae5d5Sryo error = (new_rate == 0) ? 0 : ERANGE;
121*8afae5d5Sryo return error;
122*8afae5d5Sryo }
123*8afae5d5Sryo
124*8afae5d5Sryo if (parent_rate > new_rate) {
125*8afae5d5Sryo n = parent_rate / new_rate;
126*8afae5d5Sryo parent_rate /= n;
127*8afae5d5Sryo } else {
128*8afae5d5Sryo n = 1;
129*8afae5d5Sryo }
130*8afae5d5Sryo
131*8afae5d5Sryo #define DIV_ROUND_OFF(x, y) (((x) + (y) / 2) / (y))
132*8afae5d5Sryo m_max = __SHIFTOUT(pll->m.mask, pll->m.mask);
133*8afae5d5Sryo frac_max = __SHIFTOUT(pll->frac.mask, pll->frac.mask);
134*8afae5d5Sryo tmp = DIV_ROUND_OFF(new_rate * (frac_max + 1), parent_rate);
135*8afae5d5Sryo m = tmp / (frac_max + 1);
136*8afae5d5Sryo frac = tmp & frac_max;
137*8afae5d5Sryo
138*8afae5d5Sryo if (m > m_max)
139*8afae5d5Sryo return ERANGE;
140*8afae5d5Sryo
141*8afae5d5Sryo CLK_LOCK(sc);
142*8afae5d5Sryo
143*8afae5d5Sryo /* reset */
144*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->reset.reg, pll->reset.mask, 1);
145*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->reset.reg, pll->reset.mask, 0);
146*8afae5d5Sryo error = meson_clk_pll_wait_lock(sc, pll);
147*8afae5d5Sryo if (error != 0)
148*8afae5d5Sryo goto failure;
149*8afae5d5Sryo
150*8afae5d5Sryo /* disable */
151*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->reset.reg, pll->reset.mask, 1);
152*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->enable.reg, pll->enable.mask, 0);
153*8afae5d5Sryo
154*8afae5d5Sryo /* write new M, N, and FRAC */
155*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->m.reg, pll->m.mask, m);
156*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->n.reg, pll->n.mask, n);
157*8afae5d5Sryo if (pll->frac.mask) {
158*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->frac.reg, pll->frac.mask, frac);
159*8afae5d5Sryo }
160*8afae5d5Sryo
161*8afae5d5Sryo /* enable */
162*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->reset.reg, pll->reset.mask, 1);
163*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->enable.reg, pll->enable.mask, 1);
164*8afae5d5Sryo DELAY(1000);
165*8afae5d5Sryo CLK_WRITE_BITS(sc, pll->reset.reg, pll->reset.mask, 0);
166*8afae5d5Sryo error = meson_clk_pll_wait_lock(sc, pll);
167*8afae5d5Sryo failure:
168*8afae5d5Sryo CLK_UNLOCK(sc);
169*8afae5d5Sryo
170*8afae5d5Sryo return error;
171*8afae5d5Sryo }
172*8afae5d5Sryo
173912cfa14Sjmcneill const char *
meson_clk_pll_get_parent(struct meson_clk_softc * sc,struct meson_clk_clk * clk)174912cfa14Sjmcneill meson_clk_pll_get_parent(struct meson_clk_softc *sc,
175912cfa14Sjmcneill struct meson_clk_clk *clk)
176912cfa14Sjmcneill {
177912cfa14Sjmcneill struct meson_clk_pll *pll = &clk->u.pll;
178912cfa14Sjmcneill
179912cfa14Sjmcneill KASSERT(clk->type == MESON_CLK_PLL);
180912cfa14Sjmcneill
181912cfa14Sjmcneill return pll->parent;
182912cfa14Sjmcneill }
183