drivers/clk/samsung/clk-exynos5-subcmu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (c) 2018 Samsung Electronics Co., Ltd.
   4 // Author: Marek Szyprowski <m.szyprowski@samsung.com>
   5 // Common Clock Framework support for Exynos5 power-domain dependent clocks
   6
   7 #include <linux/io.h>
   8 #include <linux/of_platform.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/pm_domain.h>
  11 #include <linux/pm_runtime.h>
  12
  13 #include "clk.h"
  14 #include "clk-exynos5-subcmu.h"
  15
  16 static struct samsung_clk_provider *ctx;
  17 static const struct exynos5_subcmu_info **cmu;
  18 static int nr_cmus;
  19
  20 static void exynos5_subcmu_clk_save(void __iomem *base,
  21                                     struct exynos5_subcmu_reg_dump *rd,
  22                                     unsigned int num_regs)
  23 {
  24         for (; num_regs > 0; --num_regs, ++rd) {
  25                 rd->save = readl(base + rd->offset);
  26                 writel((rd->save & ~rd->mask) | rd->value, base + rd->offset);
  27                 rd->save &= rd->mask;
  28         }
  29 };
  30
  31 static void exynos5_subcmu_clk_restore(void __iomem *base,
  32                                        struct exynos5_subcmu_reg_dump *rd,
  33                                        unsigned int num_regs)
  34 {
  35         for (; num_regs > 0; --num_regs, ++rd)
  36                 writel((readl(base + rd->offset) & ~rd->mask) | rd->save,
  37                        base + rd->offset);
  38 }
  39
  40 static void exynos5_subcmu_defer_gate(struct samsung_clk_provider *ctx,
  41                               const struct samsung_gate_clock *list, int nr_clk)
  42 {
  43         while (nr_clk--)
  44                 samsung_clk_add_lookup(ctx, ERR_PTR(-EPROBE_DEFER), list++->id);
  45 }
  46
  47 /*
  48  * Pass the needed clock provider context and register sub-CMU clocks
  49  *
  50  * NOTE: This function has to be called from the main, OF_CLK_DECLARE-
  51  * initialized clock provider driver. This happens very early during boot
  52  * process. Then this driver, during core_initcall registers two platform
  53  * drivers: one which binds to the same device-tree node as OF_CLK_DECLARE
  54  * driver and second, for handling its per-domain child-devices. Those
  55  * platform drivers are bound to their devices a bit later in arch_initcall,
  56  * when OF-core populates all device-tree nodes.
  57  */
  58 void exynos5_subcmus_init(struct samsung_clk_provider *_ctx, int _nr_cmus,
  59                           const struct exynos5_subcmu_info **_cmu)
  60 {
  61         ctx = _ctx;
  62         cmu = _cmu;
  63         nr_cmus = _nr_cmus;
  64
  65         for (; _nr_cmus--; _cmu++) {
  66                 exynos5_subcmu_defer_gate(ctx, (*_cmu)->gate_clks,
  67                                           (*_cmu)->nr_gate_clks);
  68                 exynos5_subcmu_clk_save(ctx->reg_base, (*_cmu)->suspend_regs,
  69                                         (*_cmu)->nr_suspend_regs);
  70         }
  71 }
  72
  73 static int __maybe_unused exynos5_subcmu_suspend(struct device *dev)
  74 {
  75         struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
  76         unsigned long flags;
  77
  78         spin_lock_irqsave(&ctx->lock, flags);
  79         exynos5_subcmu_clk_save(ctx->reg_base, info->suspend_regs,
  80                                 info->nr_suspend_regs);
  81         spin_unlock_irqrestore(&ctx->lock, flags);
  82
  83         return 0;
  84 }
  85
  86 static int __maybe_unused exynos5_subcmu_resume(struct device *dev)
  87 {
  88         struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
  89         unsigned long flags;
  90
  91         spin_lock_irqsave(&ctx->lock, flags);
  92         exynos5_subcmu_clk_restore(ctx->reg_base, info->suspend_regs,
  93                                    info->nr_suspend_regs);
  94         spin_unlock_irqrestore(&ctx->lock, flags);
  95
  96         return 0;
  97 }
  98
  99 static int __init exynos5_subcmu_probe(struct platform_device *pdev)
 100 {
 101         struct device *dev = &pdev->dev;
 102         struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
 103
 104         pm_runtime_set_suspended(dev);
 105         pm_runtime_enable(dev);
 106         pm_runtime_get(dev);
 107
 108         ctx->dev = dev;
 109         samsung_clk_register_div(ctx, info->div_clks, info->nr_div_clks);
 110         samsung_clk_register_gate(ctx, info->gate_clks, info->nr_gate_clks);
 111         ctx->dev = NULL;
 112
 113         pm_runtime_put_sync(dev);
 114
 115         return 0;
 116 }
 117
 118 static const struct dev_pm_ops exynos5_subcmu_pm_ops = {
 119         SET_RUNTIME_PM_OPS(exynos5_subcmu_suspend,
 120                            exynos5_subcmu_resume, NULL)
 121         SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 122                                      pm_runtime_force_resume)
 123 };
 124
 125 static struct platform_driver exynos5_subcmu_driver __refdata = {
 126         .driver = {
 127                 .name = "exynos5-subcmu",
 128                 .suppress_bind_attrs = true,
 129                 .pm = &exynos5_subcmu_pm_ops,
 130         },
 131         .probe = exynos5_subcmu_probe,
 132 };
 133
 134 static int __init exynos5_clk_register_subcmu(struct device *parent,
 135                                          const struct exynos5_subcmu_info *info,
 136                                               struct device_node *pd_node)
 137 {
 138         struct of_phandle_args genpdspec = { .np = pd_node };
 139         struct platform_device *pdev;
 140         int ret;
 141
 142         pdev = platform_device_alloc("exynos5-subcmu", PLATFORM_DEVID_AUTO);
 143         if (!pdev)
 144                 return -ENOMEM;
 145
 146         pdev->dev.parent = parent;
 147         platform_set_drvdata(pdev, (void *)info);
 148         of_genpd_add_device(&genpdspec, &pdev->dev);
 149         ret = platform_device_add(pdev);
 150         if (ret)
 151                 platform_device_put(pdev);
 152
 153         return ret;
 154 }
 155
 156 static int __init exynos5_clk_probe(struct platform_device *pdev)
 157 {
 158         struct device_node *np;
 159         const char *name;
 160         int i;
 161
 162         for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
 163                 if (of_property_read_string(np, "label", &name) < 0)
 164                         continue;
 165                 for (i = 0; i < nr_cmus; i++)
 166                         if (strcmp(cmu[i]->pd_name, name) == 0)
 167                                 exynos5_clk_register_subcmu(&pdev->dev,
 168                                                             cmu[i], np);
 169         }
 170         return 0;
 171 }
 172
 173 static const struct of_device_id exynos5_clk_of_match[] = {
 174         { .compatible = "samsung,exynos5250-clock", },
 175         { .compatible = "samsung,exynos5420-clock", },
 176         { .compatible = "samsung,exynos5800-clock", },
 177         { },
 178 };
 179
 180 static struct platform_driver exynos5_clk_driver __refdata = {
 181         .driver = {
 182                 .name = "exynos5-clock",
 183                 .of_match_table = exynos5_clk_of_match,
 184                 .suppress_bind_attrs = true,
 185         },
 186         .probe = exynos5_clk_probe,
 187 };
 188
 189 static int __init exynos5_clk_drv_init(void)
 190 {
 191         platform_driver_register(&exynos5_clk_driver);
 192         platform_driver_register(&exynos5_subcmu_driver);
 193         return 0;
 194 }
 195 core_initcall(exynos5_clk_drv_init);