drivers/clk/mmp/pwr-island.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * MMP PMU power island support
   4  *
   5  * Copyright (C) 2020 Lubomir Rintel <lkundrak@v3.sk>
   6  */
   7
   8 #include <linux/pm_domain.h>
   9 #include <linux/slab.h>
  10 #include <linux/io.h>
  11
  12 #include "clk.h"
  13
  14 #define to_mmp_pm_domain(genpd) container_of(genpd, struct mmp_pm_domain, genpd)
  15
  16 struct mmp_pm_domain {
  17         struct generic_pm_domain genpd;
  18         void __iomem *reg;
  19         spinlock_t *lock;
  20         u32 power_on;
  21         u32 reset;
  22         u32 clock_enable;
  23         unsigned int flags;
  24 };
  25
  26 static int mmp_pm_domain_power_on(struct generic_pm_domain *genpd)
  27 {
  28         struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
  29         unsigned long flags = 0;
  30         u32 val;
  31
  32         if (pm_domain->lock)
  33                 spin_lock_irqsave(pm_domain->lock, flags);
  34
  35         val = readl(pm_domain->reg);
  36
  37         /* Turn on the power island */
  38         val |= pm_domain->power_on;
  39         writel(val, pm_domain->reg);
  40
  41         /* Disable isolation */
  42         val |= 0x100;
  43         writel(val, pm_domain->reg);
  44
  45         /* Some blocks need to be reset after a power up */
  46         if (pm_domain->reset || pm_domain->clock_enable) {
  47                 u32 after_power_on = val;
  48
  49                 val &= ~pm_domain->reset;
  50                 writel(val, pm_domain->reg);
  51
  52                 val |= pm_domain->clock_enable;
  53                 writel(val, pm_domain->reg);
  54
  55                 val |= pm_domain->reset;
  56                 writel(val, pm_domain->reg);
  57
  58                 writel(after_power_on, pm_domain->reg);
  59         }
  60
  61         if (pm_domain->lock)
  62                 spin_unlock_irqrestore(pm_domain->lock, flags);
  63
  64         return 0;
  65 }
  66
  67 static int mmp_pm_domain_power_off(struct generic_pm_domain *genpd)
  68 {
  69         struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
  70         unsigned long flags = 0;
  71         u32 val;
  72
  73         if (pm_domain->flags & MMP_PM_DOMAIN_NO_DISABLE)
  74                 return 0;
  75
  76         if (pm_domain->lock)
  77                 spin_lock_irqsave(pm_domain->lock, flags);
  78
  79         /* Turn off and isolate the power island. */
  80         val = readl(pm_domain->reg);
  81         val &= ~pm_domain->power_on;
  82         val &= ~0x100;
  83         writel(val, pm_domain->reg);
  84
  85         if (pm_domain->lock)
  86                 spin_unlock_irqrestore(pm_domain->lock, flags);
  87
  88         return 0;
  89 }
  90
  91 struct generic_pm_domain *mmp_pm_domain_register(const char *name,
  92                 void __iomem *reg,
  93                 u32 power_on, u32 reset, u32 clock_enable,
  94                 unsigned int flags, spinlock_t *lock)
  95 {
  96         struct mmp_pm_domain *pm_domain;
  97
  98         pm_domain = kzalloc(sizeof(*pm_domain), GFP_KERNEL);
  99         if (!pm_domain)
 100                 return ERR_PTR(-ENOMEM);
 101
 102         pm_domain->reg = reg;
 103         pm_domain->power_on = power_on;
 104         pm_domain->reset = reset;
 105         pm_domain->clock_enable = clock_enable;
 106         pm_domain->flags = flags;
 107         pm_domain->lock = lock;
 108
 109         pm_genpd_init(&pm_domain->genpd, NULL, true);
 110         pm_domain->genpd.name = name;
 111         pm_domain->genpd.power_on = mmp_pm_domain_power_on;
 112         pm_domain->genpd.power_off = mmp_pm_domain_power_off;
 113
 114         return &pm_domain->genpd;
 115 }