drivers/clk/samsung/clk-exynos-clkout.c

   1 /*
   2  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   3  * Author: Tomasz Figa <t.figa@samsung.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Clock driver for Exynos clock output
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/clk.h>
  14 #include <linux/clk-provider.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/syscore_ops.h>
  18
  19 #define EXYNOS_CLKOUT_NR_CLKS           1
  20 #define EXYNOS_CLKOUT_PARENTS           32
  21
  22 #define EXYNOS_PMU_DEBUG_REG            0xa00
  23 #define EXYNOS_CLKOUT_DISABLE_SHIFT     0
  24 #define EXYNOS_CLKOUT_MUX_SHIFT         8
  25 #define EXYNOS4_CLKOUT_MUX_MASK         0xf
  26 #define EXYNOS5_CLKOUT_MUX_MASK         0x1f
  27
  28 struct exynos_clkout {
  29         struct clk_gate gate;
  30         struct clk_mux mux;
  31         spinlock_t slock;
  32         void __iomem *reg;
  33         u32 pmu_debug_save;
  34         struct clk_hw_onecell_data data;
  35 };
  36
  37 static struct exynos_clkout *clkout;
  38
  39 static int exynos_clkout_suspend(void)
  40 {
  41         clkout->pmu_debug_save = readl(clkout->reg + EXYNOS_PMU_DEBUG_REG);
  42
  43         return 0;
  44 }
  45
  46 static void exynos_clkout_resume(void)
  47 {
  48         writel(clkout->pmu_debug_save, clkout->reg + EXYNOS_PMU_DEBUG_REG);
  49 }
  50
  51 static struct syscore_ops exynos_clkout_syscore_ops = {
  52         .suspend = exynos_clkout_suspend,
  53         .resume = exynos_clkout_resume,
  54 };
  55
  56 static void __init exynos_clkout_init(struct device_node *node, u32 mux_mask)
  57 {
  58         const char *parent_names[EXYNOS_CLKOUT_PARENTS];
  59         struct clk *parents[EXYNOS_CLKOUT_PARENTS];
  60         int parent_count;
  61         int ret;
  62         int i;
  63
  64         clkout = kzalloc(struct_size(clkout, data.hws, EXYNOS_CLKOUT_NR_CLKS),
  65                          GFP_KERNEL);
  66         if (!clkout)
  67                 return;
  68
  69         spin_lock_init(&clkout->slock);
  70
  71         parent_count = 0;
  72         for (i = 0; i < EXYNOS_CLKOUT_PARENTS; ++i) {
  73                 char name[] = "clkoutXX";
  74
  75                 snprintf(name, sizeof(name), "clkout%d", i);
  76                 parents[i] = of_clk_get_by_name(node, name);
  77                 if (IS_ERR(parents[i])) {
  78                         parent_names[i] = "none";
  79                         continue;
  80                 }
  81
  82                 parent_names[i] = __clk_get_name(parents[i]);
  83                 parent_count = i + 1;
  84         }
  85
  86         if (!parent_count)
  87                 goto free_clkout;
  88
  89         clkout->reg = of_iomap(node, 0);
  90         if (!clkout->reg)
  91                 goto clks_put;
  92
  93         clkout->gate.reg = clkout->reg + EXYNOS_PMU_DEBUG_REG;
  94         clkout->gate.bit_idx = EXYNOS_CLKOUT_DISABLE_SHIFT;
  95         clkout->gate.flags = CLK_GATE_SET_TO_DISABLE;
  96         clkout->gate.lock = &clkout->slock;
  97
  98         clkout->mux.reg = clkout->reg + EXYNOS_PMU_DEBUG_REG;
  99         clkout->mux.mask = mux_mask;
 100         clkout->mux.shift = EXYNOS_CLKOUT_MUX_SHIFT;
 101         clkout->mux.lock = &clkout->slock;
 102
 103         clkout->data.hws[0] = clk_hw_register_composite(NULL, "clkout",
 104                                 parent_names, parent_count, &clkout->mux.hw,
 105                                 &clk_mux_ops, NULL, NULL, &clkout->gate.hw,
 106                                 &clk_gate_ops, CLK_SET_RATE_PARENT
 107                                 | CLK_SET_RATE_NO_REPARENT);
 108         if (IS_ERR(clkout->data.hws[0]))
 109                 goto err_unmap;
 110
 111         clkout->data.num = EXYNOS_CLKOUT_NR_CLKS;
 112         ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, &clkout->data);
 113         if (ret)
 114                 goto err_clk_unreg;
 115
 116         register_syscore_ops(&exynos_clkout_syscore_ops);
 117
 118         return;
 119
 120 err_clk_unreg:
 121         clk_hw_unregister(clkout->data.hws[0]);
 122 err_unmap:
 123         iounmap(clkout->reg);
 124 clks_put:
 125         for (i = 0; i < EXYNOS_CLKOUT_PARENTS; ++i)
 126                 if (!IS_ERR(parents[i]))
 127                         clk_put(parents[i]);
 128 free_clkout:
 129         kfree(clkout);
 130
 131         pr_err("%s: failed to register clkout clock\n", __func__);
 132 }
 133
 134 /*
 135  * We use CLK_OF_DECLARE_DRIVER initialization method to avoid setting
 136  * the OF_POPULATED flag on the pmu device tree node, so later the
 137  * Exynos PMU platform device can be properly probed with PMU driver.
 138  */
 139
 140 static void __init exynos4_clkout_init(struct device_node *node)
 141 {
 142         exynos_clkout_init(node, EXYNOS4_CLKOUT_MUX_MASK);
 143 }
 144 CLK_OF_DECLARE_DRIVER(exynos4210_clkout, "samsung,exynos4210-pmu",
 145                 exynos4_clkout_init);
 146 CLK_OF_DECLARE_DRIVER(exynos4412_clkout, "samsung,exynos4412-pmu",
 147                 exynos4_clkout_init);
 148 CLK_OF_DECLARE_DRIVER(exynos3250_clkout, "samsung,exynos3250-pmu",
 149                 exynos4_clkout_init);
 150
 151 static void __init exynos5_clkout_init(struct device_node *node)
 152 {
 153         exynos_clkout_init(node, EXYNOS5_CLKOUT_MUX_MASK);
 154 }
 155 CLK_OF_DECLARE_DRIVER(exynos5250_clkout, "samsung,exynos5250-pmu",
 156                 exynos5_clkout_init);
 157 CLK_OF_DECLARE_DRIVER(exynos5410_clkout, "samsung,exynos5410-pmu",
 158                 exynos5_clkout_init);
 159 CLK_OF_DECLARE_DRIVER(exynos5420_clkout, "samsung,exynos5420-pmu",
 160                 exynos5_clkout_init);
 161 CLK_OF_DECLARE_DRIVER(exynos5433_clkout, "samsung,exynos5433-pmu",
 162                 exynos5_clkout_init);