linux/drivers/clk/pxa/clk-pxa.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Marvell PXA family clocks
   4 *
   5 * Copyright (C) 2014 Robert Jarzmik
   6 *
   7 * Common clock code for PXA clocks ("CKEN" type clocks + DT)
   8 */
   9#include <linux/clk.h>
  10#include <linux/clk-provider.h>
  11#include <linux/clkdev.h>
  12#include <linux/io.h>
  13#include <linux/of.h>
  14
  15#include <dt-bindings/clock/pxa-clock.h>
  16#include "clk-pxa.h"
  17
  18#define KHz 1000
  19#define MHz (1000 * 1000)
  20
  21#define MDREFR_K0DB4    (1 << 29)       /* SDCLK0 Divide by 4 Control/Status */
  22#define MDREFR_K2FREE   (1 << 25)       /* SDRAM Free-Running Control */
  23#define MDREFR_K1FREE   (1 << 24)       /* SDRAM Free-Running Control */
  24#define MDREFR_K0FREE   (1 << 23)       /* SDRAM Free-Running Control */
  25#define MDREFR_SLFRSH   (1 << 22)       /* SDRAM Self-Refresh Control/Status */
  26#define MDREFR_APD      (1 << 20)       /* SDRAM/SSRAM Auto-Power-Down Enable */
  27#define MDREFR_K2DB2    (1 << 19)       /* SDCLK2 Divide by 2 Control/Status */
  28#define MDREFR_K2RUN    (1 << 18)       /* SDCLK2 Run Control/Status */
  29#define MDREFR_K1DB2    (1 << 17)       /* SDCLK1 Divide by 2 Control/Status */
  30#define MDREFR_K1RUN    (1 << 16)       /* SDCLK1 Run Control/Status */
  31#define MDREFR_E1PIN    (1 << 15)       /* SDCKE1 Level Control/Status */
  32#define MDREFR_K0DB2    (1 << 14)       /* SDCLK0 Divide by 2 Control/Status */
  33#define MDREFR_K0RUN    (1 << 13)       /* SDCLK0 Run Control/Status */
  34#define MDREFR_E0PIN    (1 << 12)       /* SDCKE0 Level Control/Status */
  35#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2)
  36#define MDREFR_DRI_MASK 0xFFF
  37
  38static DEFINE_SPINLOCK(pxa_clk_lock);
  39
  40static struct clk *pxa_clocks[CLK_MAX];
  41static struct clk_onecell_data onecell_data = {
  42        .clks = pxa_clocks,
  43        .clk_num = CLK_MAX,
  44};
  45
  46struct pxa_clk {
  47        struct clk_hw hw;
  48        struct clk_fixed_factor lp;
  49        struct clk_fixed_factor hp;
  50        struct clk_gate gate;
  51        bool (*is_in_low_power)(void);
  52};
  53
  54#define to_pxa_clk(_hw) container_of(_hw, struct pxa_clk, hw)
  55
  56static unsigned long cken_recalc_rate(struct clk_hw *hw,
  57                                      unsigned long parent_rate)
  58{
  59        struct pxa_clk *pclk = to_pxa_clk(hw);
  60        struct clk_fixed_factor *fix;
  61
  62        if (!pclk->is_in_low_power || pclk->is_in_low_power())
  63                fix = &pclk->lp;
  64        else
  65                fix = &pclk->hp;
  66        __clk_hw_set_clk(&fix->hw, hw);
  67        return clk_fixed_factor_ops.recalc_rate(&fix->hw, parent_rate);
  68}
  69
  70static const struct clk_ops cken_rate_ops = {
  71        .recalc_rate = cken_recalc_rate,
  72};
  73
  74static u8 cken_get_parent(struct clk_hw *hw)
  75{
  76        struct pxa_clk *pclk = to_pxa_clk(hw);
  77
  78        if (!pclk->is_in_low_power)
  79                return 0;
  80        return pclk->is_in_low_power() ? 0 : 1;
  81}
  82
  83static const struct clk_ops cken_mux_ops = {
  84        .get_parent = cken_get_parent,
  85        .set_parent = dummy_clk_set_parent,
  86};
  87
  88void __init clkdev_pxa_register(int ckid, const char *con_id,
  89                                const char *dev_id, struct clk *clk)
  90{
  91        if (!IS_ERR(clk) && (ckid != CLK_NONE))
  92                pxa_clocks[ckid] = clk;
  93        if (!IS_ERR(clk))
  94                clk_register_clkdev(clk, con_id, dev_id);
  95}
  96
  97int __init clk_pxa_cken_init(const struct desc_clk_cken *clks, int nb_clks)
  98{
  99        int i;
 100        struct pxa_clk *pxa_clk;
 101        struct clk *clk;
 102
 103        for (i = 0; i < nb_clks; i++) {
 104                pxa_clk = kzalloc(sizeof(*pxa_clk), GFP_KERNEL);
 105                pxa_clk->is_in_low_power = clks[i].is_in_low_power;
 106                pxa_clk->lp = clks[i].lp;
 107                pxa_clk->hp = clks[i].hp;
 108                pxa_clk->gate = clks[i].gate;
 109                pxa_clk->gate.lock = &pxa_clk_lock;
 110                clk = clk_register_composite(NULL, clks[i].name,
 111                                             clks[i].parent_names, 2,
 112                                             &pxa_clk->hw, &cken_mux_ops,
 113                                             &pxa_clk->hw, &cken_rate_ops,
 114                                             &pxa_clk->gate.hw, &clk_gate_ops,
 115                                             clks[i].flags);
 116                clkdev_pxa_register(clks[i].ckid, clks[i].con_id,
 117                                    clks[i].dev_id, clk);
 118        }
 119        return 0;
 120}
 121
 122void __init clk_pxa_dt_common_init(struct device_node *np)
 123{
 124        of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data);
 125}
 126
 127void pxa2xx_core_turbo_switch(bool on)
 128{
 129        unsigned long flags;
 130        unsigned int unused, clkcfg;
 131
 132        local_irq_save(flags);
 133
 134        asm("mrc p14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
 135        clkcfg &= ~CLKCFG_TURBO & ~CLKCFG_HALFTURBO;
 136        if (on)
 137                clkcfg |= CLKCFG_TURBO;
 138        clkcfg |= CLKCFG_FCS;
 139
 140        asm volatile(
 141        "       b       2f\n"
 142        "       .align  5\n"
 143        "1:     mcr     p14, 0, %1, c6, c0, 0\n"
 144        "       b       3f\n"
 145        "2:     b       1b\n"
 146        "3:     nop\n"
 147                : "=&r" (unused) : "r" (clkcfg));
 148
 149        local_irq_restore(flags);
 150}
 151
 152void pxa2xx_cpll_change(struct pxa2xx_freq *freq,
 153                        u32 (*mdrefr_dri)(unsigned int), void __iomem *mdrefr,
 154                        void __iomem *cccr)
 155{
 156        unsigned int clkcfg = freq->clkcfg;
 157        unsigned int unused, preset_mdrefr, postset_mdrefr;
 158        unsigned long flags;
 159
 160        local_irq_save(flags);
 161
 162        /* Calculate the next MDREFR.  If we're slowing down the SDRAM clock
 163         * we need to preset the smaller DRI before the change.  If we're
 164         * speeding up we need to set the larger DRI value after the change.
 165         */
 166        preset_mdrefr = postset_mdrefr = readl(mdrefr);
 167        if ((preset_mdrefr & MDREFR_DRI_MASK) > mdrefr_dri(freq->membus_khz)) {
 168                preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK);
 169                preset_mdrefr |= mdrefr_dri(freq->membus_khz);
 170        }
 171        postset_mdrefr =
 172                (postset_mdrefr & ~MDREFR_DRI_MASK) |
 173                mdrefr_dri(freq->membus_khz);
 174
 175        /* If we're dividing the memory clock by two for the SDRAM clock, this
 176         * must be set prior to the change.  Clearing the divide must be done
 177         * after the change.
 178         */
 179        if (freq->div2) {
 180                preset_mdrefr  |= MDREFR_DB2_MASK;
 181                postset_mdrefr |= MDREFR_DB2_MASK;
 182        } else {
 183                postset_mdrefr &= ~MDREFR_DB2_MASK;
 184        }
 185
 186        /* Set new the CCCR and prepare CLKCFG */
 187        writel(freq->cccr, cccr);
 188
 189        asm volatile(
 190        "       ldr     r4, [%1]\n"
 191        "       b       2f\n"
 192        "       .align  5\n"
 193        "1:     str     %3, [%1]                /* preset the MDREFR */\n"
 194        "       mcr     p14, 0, %2, c6, c0, 0   /* set CLKCFG[FCS] */\n"
 195        "       str     %4, [%1]                /* postset the MDREFR */\n"
 196        "       b       3f\n"
 197        "2:     b       1b\n"
 198        "3:     nop\n"
 199             : "=&r" (unused)
 200             : "r" (mdrefr), "r" (clkcfg), "r" (preset_mdrefr),
 201               "r" (postset_mdrefr)
 202             : "r4", "r5");
 203
 204        local_irq_restore(flags);
 205}
 206
 207int pxa2xx_determine_rate(struct clk_rate_request *req,
 208                          struct pxa2xx_freq *freqs, int nb_freqs)
 209{
 210        int i, closest_below = -1, closest_above = -1;
 211        unsigned long rate;
 212
 213        for (i = 0; i < nb_freqs; i++) {
 214                rate = freqs[i].cpll;
 215                if (rate == req->rate)
 216                        break;
 217                if (rate < req->min_rate)
 218                        continue;
 219                if (rate > req->max_rate)
 220                        continue;
 221                if (rate <= req->rate)
 222                        closest_below = i;
 223                if ((rate >= req->rate) && (closest_above == -1))
 224                        closest_above = i;
 225        }
 226
 227        req->best_parent_hw = NULL;
 228
 229        if (i < nb_freqs) {
 230                rate = req->rate;
 231        } else if (closest_below >= 0) {
 232                rate = freqs[closest_below].cpll;
 233        } else if (closest_above >= 0) {
 234                rate = freqs[closest_above].cpll;
 235        } else {
 236                pr_debug("%s(rate=%lu) no match\n", __func__, req->rate);
 237                return -EINVAL;
 238        }
 239
 240        pr_debug("%s(rate=%lu) rate=%lu\n", __func__, req->rate, rate);
 241        req->rate = rate;
 242
 243        return 0;
 244}
 245