LXR linux/drivers/clk/versatile/clk-sp810.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Copyright (C) 2013 ARM Limited
   5 */
   6
   7#include <linux/amba/sp810.h>
   8#include <linux/slab.h>
   9#include <linux/clk.h>
  10#include <linux/clk-provider.h>
  11#include <linux/err.h>
  12#include <linux/io.h>
  13#include <linux/of.h>
  14#include <linux/of_address.h>
  15
  16#define to_clk_sp810_timerclken(_hw) \
  17                container_of(_hw, struct clk_sp810_timerclken, hw)
  18
  19struct clk_sp810;
  20
  21struct clk_sp810_timerclken {
  22        struct clk_hw hw;
  23        struct clk *clk;
  24        struct clk_sp810 *sp810;
  25        int channel;
  26};
  27
  28struct clk_sp810 {
  29        struct device_node *node;
  30        void __iomem *base;
  31        spinlock_t lock;
  32        struct clk_sp810_timerclken timerclken[4];
  33};
  34
  35static u8 clk_sp810_timerclken_get_parent(struct clk_hw *hw)
  36{
  37        struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
  38        u32 val = readl(timerclken->sp810->base + SCCTRL);
  39
  40        return !!(val & (1 << SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel)));
  41}
  42
  43static int clk_sp810_timerclken_set_parent(struct clk_hw *hw, u8 index)
  44{
  45        struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
  46        struct clk_sp810 *sp810 = timerclken->sp810;
  47        u32 val, shift = SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel);
  48        unsigned long flags = 0;
  49
  50        if (WARN_ON(index > 1))
  51                return -EINVAL;
  52
  53        spin_lock_irqsave(&sp810->lock, flags);
  54
  55        val = readl(sp810->base + SCCTRL);
  56        val &= ~(1 << shift);
  57        val |= index << shift;
  58        writel(val, sp810->base + SCCTRL);
  59
  60        spin_unlock_irqrestore(&sp810->lock, flags);
  61
  62        return 0;
  63}
  64
  65static const struct clk_ops clk_sp810_timerclken_ops = {
  66        .get_parent = clk_sp810_timerclken_get_parent,
  67        .set_parent = clk_sp810_timerclken_set_parent,
  68};
  69
  70static struct clk *clk_sp810_timerclken_of_get(struct of_phandle_args *clkspec,
  71                void *data)
  72{
  73        struct clk_sp810 *sp810 = data;
  74
  75        if (WARN_ON(clkspec->args_count != 1 ||
  76                    clkspec->args[0] >= ARRAY_SIZE(sp810->timerclken)))
  77                return NULL;
  78
  79        return sp810->timerclken[clkspec->args[0]].clk;
  80}
  81
  82static void __init clk_sp810_of_setup(struct device_node *node)
  83{
  84        struct clk_sp810 *sp810 = kzalloc(sizeof(*sp810), GFP_KERNEL);
  85        const char *parent_names[2];
  86        int num = ARRAY_SIZE(parent_names);
  87        char name[12];
  88        struct clk_init_data init;
  89        static int instance;
  90        int i;
  91        bool deprecated;
  92
  93        if (!sp810)
  94                return;
  95
  96        if (of_clk_parent_fill(node, parent_names, num) != num) {
  97                pr_warn("Failed to obtain parent clocks for SP810!\n");
  98                kfree(sp810);
  99                return;
 100        }
 101
 102        sp810->node = node;
 103        sp810->base = of_iomap(node, 0);
 104        spin_lock_init(&sp810->lock);
 105
 106        init.name = name;
 107        init.ops = &clk_sp810_timerclken_ops;
 108        init.flags = 0;
 109        init.parent_names = parent_names;
 110        init.num_parents = num;
 111
 112        deprecated = !of_find_property(node, "assigned-clock-parents", NULL);
 113
 114        for (i = 0; i < ARRAY_SIZE(sp810->timerclken); i++) {
 115                snprintf(name, sizeof(name), "sp810_%d_%d", instance, i);
 116
 117                sp810->timerclken[i].sp810 = sp810;
 118                sp810->timerclken[i].channel = i;
 119                sp810->timerclken[i].hw.init = &init;
 120
 121                /*
 122                 * If DT isn't setting the parent, force it to be
 123                 * the 1 MHz clock without going through the framework.
 124                 * We do this before clk_register() so that it can determine
 125                 * the parent and setup the tree properly.
 126                 */
 127                if (deprecated)
 128                        init.ops->set_parent(&sp810->timerclken[i].hw, 1);
 129
 130                sp810->timerclken[i].clk = clk_register(NULL,
 131                                &sp810->timerclken[i].hw);
 132                WARN_ON(IS_ERR(sp810->timerclken[i].clk));
 133        }
 134
 135        of_clk_add_provider(node, clk_sp810_timerclken_of_get, sp810);
 136        instance++;
 137}
 138CLK_OF_DECLARE(sp810, "arm,sp810", clk_sp810_of_setup);
 139