1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * DPLL + CORE_CLK composite clock functions
4 *
5 * Copyright (C) 2005-2008 Texas Instruments, Inc.
6 * Copyright (C) 2004-2010 Nokia Corporation
7 *
8 * Contacts:
9 * Richard Woodruff <r-woodruff2@ti.com>
10 * Paul Walmsley
11 *
12 * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
13 * Gordon McNutt and RidgeRun, Inc.
14 *
15 * XXX The DPLL and CORE clocks should be split into two separate clock
16 * types.
17 */
18#undef DEBUG
19
20#include <linux/kernel.h>
21#include <linux/errno.h>
22#include <linux/clk.h>
23#include <linux/clk/ti.h>
24#include <linux/io.h>
25
26#include "clock.h"
27#include "clock2xxx.h"
28#include "opp2xxx.h"
29#include "cm2xxx.h"
30#include "cm-regbits-24xx.h"
31#include "sdrc.h"
32#include "sram.h"
33
34/* #define DOWN_VARIABLE_DPLL 1 */ /* Experimental */
35
36/*
37 * dpll_core_ck: pointer to the combined dpll_ck + core_ck on OMAP2xxx
38 * (currently defined as "dpll_ck" in the OMAP2xxx clock tree). Set
39 * during dpll_ck init and used later by omap2xxx_clk_get_core_rate().
40 */
41static struct clk_hw_omap *dpll_core_ck;
42
43/**
44 * omap2xxx_clk_get_core_rate - return the CORE_CLK rate
45 *
46 * Returns the CORE_CLK rate. CORE_CLK can have one of three rate
47 * sources on OMAP2xxx: the DPLL CLKOUT rate, DPLL CLKOUTX2, or 32KHz
48 * (the latter is unusual). This currently should be called with
49 * struct clk *dpll_ck, which is a composite clock of dpll_ck and
50 * core_ck.
51 */
52unsigned long omap2xxx_clk_get_core_rate(void)
53{
54 long long core_clk;
55 u32 v;
56
57 WARN_ON(!dpll_core_ck);
58
59 core_clk = omap2_get_dpll_rate(clk: dpll_core_ck);
60
61 v = omap2xxx_cm_get_core_clk_src();
62
63 if (v == CORE_CLK_SRC_32K)
64 core_clk = 32768;
65 else
66 core_clk *= v;
67
68 return core_clk;
69}
70
71/*
72 * Uses the current prcm set to tell if a rate is valid.
73 * You can go slower, but not faster within a given rate set.
74 */
75static long omap2_dpllcore_round_rate(unsigned long target_rate)
76{
77 u32 high, low, core_clk_src;
78
79 core_clk_src = omap2xxx_cm_get_core_clk_src();
80
81 if (core_clk_src == CORE_CLK_SRC_DPLL) { /* DPLL clockout */
82 high = curr_prcm_set->dpll_speed * 2;
83 low = curr_prcm_set->dpll_speed;
84 } else { /* DPLL clockout x 2 */
85 high = curr_prcm_set->dpll_speed;
86 low = curr_prcm_set->dpll_speed / 2;
87 }
88
89#ifdef DOWN_VARIABLE_DPLL
90 if (target_rate > high)
91 return high;
92 else
93 return target_rate;
94#else
95 if (target_rate > low)
96 return high;
97 else
98 return low;
99#endif
100
101}
102
103unsigned long omap2_dpllcore_recalc(struct clk_hw *hw,
104 unsigned long parent_rate)
105{
106 return omap2xxx_clk_get_core_rate();
107}
108
109int omap2_reprogram_dpllcore(struct clk_hw *hw, unsigned long rate,
110 unsigned long parent_rate)
111{
112 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
113 u32 cur_rate, low, mult, div, valid_rate, done_rate;
114 u32 bypass = 0;
115 struct prcm_config tmpset;
116 const struct dpll_data *dd;
117
118 cur_rate = omap2xxx_clk_get_core_rate();
119 mult = omap2xxx_cm_get_core_clk_src();
120
121 if ((rate == (cur_rate / 2)) && (mult == 2)) {
122 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, force: 1);
123 } else if ((rate == (cur_rate * 2)) && (mult == 1)) {
124 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, force: 1);
125 } else if (rate != cur_rate) {
126 valid_rate = omap2_dpllcore_round_rate(target_rate: rate);
127 if (valid_rate != rate)
128 return -EINVAL;
129
130 if (mult == 1)
131 low = curr_prcm_set->dpll_speed;
132 else
133 low = curr_prcm_set->dpll_speed / 2;
134
135 dd = clk->dpll_data;
136 if (!dd)
137 return -EINVAL;
138
139 tmpset.cm_clksel1_pll =
140 omap_clk_ll_ops.clk_readl(&dd->mult_div1_reg);
141 tmpset.cm_clksel1_pll &= ~(dd->mult_mask |
142 dd->div1_mask);
143 div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
144 tmpset.cm_clksel2_pll = omap2xxx_cm_get_core_pll_config();
145 tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK;
146 if (rate > low) {
147 tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2;
148 mult = ((rate / 2) / 1000000);
149 done_rate = CORE_CLK_SRC_DPLL_X2;
150 } else {
151 tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL;
152 mult = (rate / 1000000);
153 done_rate = CORE_CLK_SRC_DPLL;
154 }
155 tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
156 tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
157
158 /* Worst case */
159 tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
160
161 if (rate == curr_prcm_set->xtal_speed) /* If asking for 1-1 */
162 bypass = 1;
163
164 /* For omap2xxx_sdrc_init_params() */
165 omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, force: 1);
166
167 /* Force dll lock mode */
168 omap2_set_prcm(dpll_ctrl_val: tmpset.cm_clksel1_pll, sdrc_rfr_val: tmpset.base_sdrc_rfr,
169 bypass);
170
171 /* Errata: ret dll entry state */
172 omap2xxx_sdrc_init_params(force_lock_to_unlock_mode: omap2xxx_sdrc_dll_is_unlocked());
173 omap2xxx_sdrc_reprogram(level: done_rate, force: 0);
174 }
175
176 return 0;
177}
178
179/**
180 * omap2xxx_clkt_dpllcore_init - clk init function for dpll_ck
181 * @clk: struct clk *dpll_ck
182 *
183 * Store a local copy of @clk in dpll_core_ck so other code can query
184 * the core rate without having to clk_get(), which can sleep. Must
185 * only be called once. No return value. XXX If the clock
186 * registration process is ever changed such that dpll_ck is no longer
187 * statically defined, this code may need to change to increment some
188 * kind of use count on dpll_ck.
189 */
190void omap2xxx_clkt_dpllcore_init(struct clk_hw *hw)
191{
192 WARN(dpll_core_ck, "dpll_core_ck already set - should never happen");
193 dpll_core_ck = to_clk_hw_omap(hw);
194}
195

source code of linux/arch/arm/mach-omap2/clkt2xxx_dpllcore.c