drivers/clk/at91/pmc.c

   1 /*
   2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/clkdev.h>
  13 #include <linux/clk/at91_pmc.h>
  14 #include <linux/of.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regmap.h>
  18 #include <linux/syscore_ops.h>
  19
  20 #include <asm/proc-fns.h>
  21
  22 #include "pmc.h"
  23
  24 #define PMC_MAX_IDS 128
  25
  26 int of_at91_get_clk_range(struct device_node *np, const char *propname,
  27                           struct clk_range *range)
  28 {
  29         u32 min, max;
  30         int ret;
  31
  32         ret = of_property_read_u32_index(np, propname, 0, &min);
  33         if (ret)
  34                 return ret;
  35
  36         ret = of_property_read_u32_index(np, propname, 1, &max);
  37         if (ret)
  38                 return ret;
  39
  40         if (range) {
  41                 range->min = min;
  42                 range->max = max;
  43         }
  44
  45         return 0;
  46 }
  47 EXPORT_SYMBOL_GPL(of_at91_get_clk_range);
  48
  49 #ifdef CONFIG_PM
  50 static struct regmap *pmcreg;
  51
  52 static u8 registered_ids[PMC_MAX_IDS];
  53
  54 static struct
  55 {
  56         u32 scsr;
  57         u32 pcsr0;
  58         u32 uckr;
  59         u32 mor;
  60         u32 mcfr;
  61         u32 pllar;
  62         u32 mckr;
  63         u32 usb;
  64         u32 imr;
  65         u32 pcsr1;
  66         u32 pcr[PMC_MAX_IDS];
  67         u32 audio_pll0;
  68         u32 audio_pll1;
  69 } pmc_cache;
  70
  71 void pmc_register_id(u8 id)
  72 {
  73         int i;
  74
  75         for (i = 0; i < PMC_MAX_IDS; i++) {
  76                 if (registered_ids[i] == 0) {
  77                         registered_ids[i] = id;
  78                         break;
  79                 }
  80                 if (registered_ids[i] == id)
  81                         break;
  82         }
  83 }
  84
  85 static int pmc_suspend(void)
  86 {
  87         int i;
  88
  89         regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.scsr);
  90         regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0);
  91         regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr);
  92         regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor);
  93         regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr);
  94         regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar);
  95         regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr);
  96         regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb);
  97         regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr);
  98         regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1);
  99
 100         for (i = 0; registered_ids[i]; i++) {
 101                 regmap_write(pmcreg, AT91_PMC_PCR,
 102                              (registered_ids[i] & AT91_PMC_PCR_PID_MASK));
 103                 regmap_read(pmcreg, AT91_PMC_PCR,
 104                             &pmc_cache.pcr[registered_ids[i]]);
 105         }
 106
 107         return 0;
 108 }
 109
 110 static bool pmc_ready(unsigned int mask)
 111 {
 112         unsigned int status;
 113
 114         regmap_read(pmcreg, AT91_PMC_SR, &status);
 115
 116         return ((status & mask) == mask) ? 1 : 0;
 117 }
 118
 119 static void pmc_resume(void)
 120 {
 121         int i;
 122         u32 tmp;
 123         u32 mask = AT91_PMC_MCKRDY | AT91_PMC_LOCKA;
 124
 125         regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
 126         if (pmc_cache.mckr != tmp)
 127                 pr_warn("MCKR was not configured properly by the firmware\n");
 128         regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp);
 129         if (pmc_cache.pllar != tmp)
 130                 pr_warn("PLLAR was not configured properly by the firmware\n");
 131
 132         regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.scsr);
 133         regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0);
 134         regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr);
 135         regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor);
 136         regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr);
 137         regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb);
 138         regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr);
 139         regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1);
 140
 141         for (i = 0; registered_ids[i]; i++) {
 142                 regmap_write(pmcreg, AT91_PMC_PCR,
 143                              pmc_cache.pcr[registered_ids[i]] |
 144                              AT91_PMC_PCR_CMD);
 145         }
 146
 147         if (pmc_cache.uckr & AT91_PMC_UPLLEN)
 148                 mask |= AT91_PMC_LOCKU;
 149
 150         while (!pmc_ready(mask))
 151                 cpu_relax();
 152 }
 153
 154 static struct syscore_ops pmc_syscore_ops = {
 155         .suspend = pmc_suspend,
 156         .resume = pmc_resume,
 157 };
 158
 159 static const struct of_device_id sama5d2_pmc_dt_ids[] = {
 160         { .compatible = "atmel,sama5d2-pmc" },
 161         { /* sentinel */ }
 162 };
 163
 164 static int __init pmc_register_ops(void)
 165 {
 166         struct device_node *np;
 167
 168         np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);
 169
 170         pmcreg = syscon_node_to_regmap(np);
 171         if (IS_ERR(pmcreg))
 172                 return PTR_ERR(pmcreg);
 173
 174         register_syscore_ops(&pmc_syscore_ops);
 175
 176         return 0;
 177 }
 178 /* This has to happen before arch_initcall because of the tcb_clksrc driver */
 179 postcore_initcall(pmc_register_ops);
 180 #endif