drivers/clk/pxa/clk-pxa.c

   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 #include <linux/soc/pxa/smemc.h>
  15
  16 #include <dt-bindings/clock/pxa-clock.h>
  17 #include "clk-pxa.h"
  18
  19 #define KHz 1000
  20 #define MHz (1000 * 1000)
  21
  22 #define MDREFR_K0DB4    (1 << 29)       /* SDCLK0 Divide by 4 Control/Status */
  23 #define MDREFR_K2FREE   (1 << 25)       /* SDRAM Free-Running Control */
  24 #define MDREFR_K1FREE   (1 << 24)       /* SDRAM Free-Running Control */
  25 #define MDREFR_K0FREE   (1 << 23)       /* SDRAM Free-Running Control */
  26 #define MDREFR_SLFRSH   (1 << 22)       /* SDRAM Self-Refresh Control/Status */
  27 #define MDREFR_APD      (1 << 20)       /* SDRAM/SSRAM Auto-Power-Down Enable */
  28 #define MDREFR_K2DB2    (1 << 19)       /* SDCLK2 Divide by 2 Control/Status */
  29 #define MDREFR_K2RUN    (1 << 18)       /* SDCLK2 Run Control/Status */
  30 #define MDREFR_K1DB2    (1 << 17)       /* SDCLK1 Divide by 2 Control/Status */
  31 #define MDREFR_K1RUN    (1 << 16)       /* SDCLK1 Run Control/Status */
  32 #define MDREFR_E1PIN    (1 << 15)       /* SDCKE1 Level Control/Status */
  33 #define MDREFR_K0DB2    (1 << 14)       /* SDCLK0 Divide by 2 Control/Status */
  34 #define MDREFR_K0RUN    (1 << 13)       /* SDCLK0 Run Control/Status */
  35 #define MDREFR_E0PIN    (1 << 12)       /* SDCKE0 Level Control/Status */
  36 #define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2)
  37 #define MDREFR_DRI_MASK 0xFFF
  38
  39 static DEFINE_SPINLOCK(pxa_clk_lock);
  40
  41 static struct clk *pxa_clocks[CLK_MAX];
  42 static struct clk_onecell_data onecell_data = {
  43         .clks = pxa_clocks,
  44         .clk_num = CLK_MAX,
  45 };
  46
  47 struct pxa_clk {
  48         struct clk_hw hw;
  49         struct clk_fixed_factor lp;
  50         struct clk_fixed_factor hp;
  51         struct clk_gate gate;
  52         bool (*is_in_low_power)(void);
  53 };
  54
  55 #define to_pxa_clk(_hw) container_of(_hw, struct pxa_clk, hw)
  56
  57 static unsigned long cken_recalc_rate(struct clk_hw *hw,
  58                                       unsigned long parent_rate)
  59 {
  60         struct pxa_clk *pclk = to_pxa_clk(hw);
  61         struct clk_fixed_factor *fix;
  62
  63         if (!pclk->is_in_low_power || pclk->is_in_low_power())
  64                 fix = &pclk->lp;
  65         else
  66                 fix = &pclk->hp;
  67         __clk_hw_set_clk(&fix->hw, hw);
  68         return clk_fixed_factor_ops.recalc_rate(&fix->hw, parent_rate);
  69 }
  70
  71 static const struct clk_ops cken_rate_ops = {
  72         .recalc_rate = cken_recalc_rate,
  73 };
  74
  75 static u8 cken_get_parent(struct clk_hw *hw)
  76 {
  77         struct pxa_clk *pclk = to_pxa_clk(hw);
  78
  79         if (!pclk->is_in_low_power)
  80                 return 0;
  81         return pclk->is_in_low_power() ? 0 : 1;
  82 }
  83
  84 static const struct clk_ops cken_mux_ops = {
  85         .get_parent = cken_get_parent,
  86         .set_parent = dummy_clk_set_parent,
  87 };
  88
  89 void __init clkdev_pxa_register(int ckid, const char *con_id,
  90                                 const char *dev_id, struct clk *clk)
  91 {
  92         if (!IS_ERR(clk) && (ckid != CLK_NONE))
  93                 pxa_clocks[ckid] = clk;
  94         if (!IS_ERR(clk))
  95                 clk_register_clkdev(clk, con_id, dev_id);
  96 }
  97
  98 int __init clk_pxa_cken_init(const struct desc_clk_cken *clks, int nb_clks)
  99 {
 100         int i;
 101         struct pxa_clk *pxa_clk;
 102         struct clk *clk;
 103
 104         for (i = 0; i < nb_clks; i++) {
 105                 pxa_clk = kzalloc(sizeof(*pxa_clk), GFP_KERNEL);
 106                 pxa_clk->is_in_low_power = clks[i].is_in_low_power;
 107                 pxa_clk->lp = clks[i].lp;
 108                 pxa_clk->hp = clks[i].hp;
 109                 pxa_clk->gate = clks[i].gate;
 110                 pxa_clk->gate.lock = &pxa_clk_lock;
 111                 clk = clk_register_composite(NULL, clks[i].name,
 112                                              clks[i].parent_names, 2,
 113                                              &pxa_clk->hw, &cken_mux_ops,
 114                                              &pxa_clk->hw, &cken_rate_ops,
 115                                              &pxa_clk->gate.hw, &clk_gate_ops,
 116                                              clks[i].flags);
 117                 clkdev_pxa_register(clks[i].ckid, clks[i].con_id,
 118                                     clks[i].dev_id, clk);
 119         }
 120         return 0;
 121 }
 122
 123 void __init clk_pxa_dt_common_init(struct device_node *np)
 124 {
 125         of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data);
 126 }
 127
 128 void pxa2xx_core_turbo_switch(bool on)
 129 {
 130         unsigned long flags;
 131         unsigned int unused, clkcfg;
 132
 133         local_irq_save(flags);
 134
 135         asm("mrc p14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
 136         clkcfg &= ~CLKCFG_TURBO & ~CLKCFG_HALFTURBO;
 137         if (on)
 138                 clkcfg |= CLKCFG_TURBO;
 139         clkcfg |= CLKCFG_FCS;
 140
 141         asm volatile(
 142         "       b       2f\n"
 143         "       .align  5\n"
 144         "1:     mcr     p14, 0, %1, c6, c0, 0\n"
 145         "       b       3f\n"
 146         "2:     b       1b\n"
 147         "3:     nop\n"
 148                 : "=&r" (unused) : "r" (clkcfg));
 149
 150         local_irq_restore(flags);
 151 }
 152
 153 void pxa2xx_cpll_change(struct pxa2xx_freq *freq,
 154                         u32 (*mdrefr_dri)(unsigned int),
 155                         void __iomem *cccr)
 156 {
 157         unsigned int clkcfg = freq->clkcfg;
 158         unsigned int unused, preset_mdrefr, postset_mdrefr;
 159         unsigned long flags;
 160         void __iomem *mdrefr = pxa_smemc_get_mdrefr();
 161
 162         local_irq_save(flags);
 163
 164         /* Calculate the next MDREFR.  If we're slowing down the SDRAM clock
 165          * we need to preset the smaller DRI before the change.  If we're
 166          * speeding up we need to set the larger DRI value after the change.
 167          */
 168         preset_mdrefr = postset_mdrefr = readl(mdrefr);
 169         if ((preset_mdrefr & MDREFR_DRI_MASK) > mdrefr_dri(freq->membus_khz)) {
 170                 preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK);
 171                 preset_mdrefr |= mdrefr_dri(freq->membus_khz);
 172         }
 173         postset_mdrefr =
 174                 (postset_mdrefr & ~MDREFR_DRI_MASK) |
 175                 mdrefr_dri(freq->membus_khz);
 176
 177         /* If we're dividing the memory clock by two for the SDRAM clock, this
 178          * must be set prior to the change.  Clearing the divide must be done
 179          * after the change.
 180          */
 181         if (freq->div2) {
 182                 preset_mdrefr  |= MDREFR_DB2_MASK;
 183                 postset_mdrefr |= MDREFR_DB2_MASK;
 184         } else {
 185                 postset_mdrefr &= ~MDREFR_DB2_MASK;
 186         }
 187
 188         /* Set new the CCCR and prepare CLKCFG */
 189         writel(freq->cccr, cccr);
 190
 191         asm volatile(
 192         "       ldr     r4, [%1]\n"
 193         "       b       2f\n"
 194         "       .align  5\n"
 195         "1:     str     %3, [%1]                /* preset the MDREFR */\n"
 196         "       mcr     p14, 0, %2, c6, c0, 0   /* set CLKCFG[FCS] */\n"
 197         "       str     %4, [%1]                /* postset the MDREFR */\n"
 198         "       b       3f\n"
 199         "2:     b       1b\n"
 200         "3:     nop\n"
 201              : "=&r" (unused)
 202              : "r" (mdrefr), "r" (clkcfg), "r" (preset_mdrefr),
 203                "r" (postset_mdrefr)
 204              : "r4", "r5");
 205
 206         local_irq_restore(flags);
 207 }
 208
 209 int pxa2xx_determine_rate(struct clk_rate_request *req,
 210                           struct pxa2xx_freq *freqs, int nb_freqs)
 211 {
 212         int i, closest_below = -1, closest_above = -1;
 213         unsigned long rate;
 214
 215         for (i = 0; i < nb_freqs; i++) {
 216                 rate = freqs[i].cpll;
 217                 if (rate == req->rate)
 218                         break;
 219                 if (rate < req->min_rate)
 220                         continue;
 221                 if (rate > req->max_rate)
 222                         continue;
 223                 if (rate <= req->rate)
 224                         closest_below = i;
 225                 if ((rate >= req->rate) && (closest_above == -1))
 226                         closest_above = i;
 227         }
 228
 229         req->best_parent_hw = NULL;
 230
 231         if (i < nb_freqs) {
 232                 rate = req->rate;
 233         } else if (closest_below >= 0) {
 234                 rate = freqs[closest_below].cpll;
 235         } else if (closest_above >= 0) {
 236                 rate = freqs[closest_above].cpll;
 237         } else {
 238                 pr_debug("%s(rate=%lu) no match\n", __func__, req->rate);
 239                 return -EINVAL;
 240         }
 241
 242         pr_debug("%s(rate=%lu) rate=%lu\n", __func__, req->rate, rate);
 243         req->rate = rate;
 244
 245         return 0;
 246 }