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