linux/drivers/clk/ti/clockdomain.c
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   1/*
   2 * OMAP clockdomain support
   3 *
   4 * Copyright (C) 2013 Texas Instruments, Inc.
   5 *
   6 * Tero Kristo <t-kristo@ti.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 *
  12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13 * kind, whether express or implied; without even the implied warranty
  14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#include <linux/clk.h>
  19#include <linux/clk-provider.h>
  20#include <linux/slab.h>
  21#include <linux/of.h>
  22#include <linux/of_address.h>
  23#include <linux/clk/ti.h>
  24
  25#include "clock.h"
  26
  27#undef pr_fmt
  28#define pr_fmt(fmt) "%s: " fmt, __func__
  29
  30/**
  31 * omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
  32 * @hw: struct clk_hw * of the clock being enabled
  33 *
  34 * Increment the usecount of the clockdomain of the clock pointed to
  35 * by @hw; if the usecount is 1, the clockdomain will be "enabled."
  36 * Only needed for clocks that don't use omap2_dflt_clk_enable() as
  37 * their enable function pointer.  Passes along the return value of
  38 * clkdm_clk_enable(), -EINVAL if @hw is not associated with a
  39 * clockdomain, or 0 if clock framework-based clockdomain control is
  40 * not implemented.
  41 */
  42int omap2_clkops_enable_clkdm(struct clk_hw *hw)
  43{
  44        struct clk_hw_omap *clk;
  45        int ret = 0;
  46
  47        clk = to_clk_hw_omap(hw);
  48
  49        if (unlikely(!clk->clkdm)) {
  50                pr_err("%s: %s: no clkdm set ?!\n", __func__,
  51                       clk_hw_get_name(hw));
  52                return -EINVAL;
  53        }
  54
  55        if (unlikely(clk->enable_reg))
  56                pr_err("%s: %s: should use dflt_clk_enable ?!\n", __func__,
  57                       clk_hw_get_name(hw));
  58
  59        if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
  60                pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
  61                       __func__, clk_hw_get_name(hw));
  62                return 0;
  63        }
  64
  65        ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
  66        WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
  67             __func__, clk_hw_get_name(hw), clk->clkdm_name, ret);
  68
  69        return ret;
  70}
  71
  72/**
  73 * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
  74 * @hw: struct clk_hw * of the clock being disabled
  75 *
  76 * Decrement the usecount of the clockdomain of the clock pointed to
  77 * by @hw; if the usecount is 0, the clockdomain will be "disabled."
  78 * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
  79 * disable function pointer.  No return value.
  80 */
  81void omap2_clkops_disable_clkdm(struct clk_hw *hw)
  82{
  83        struct clk_hw_omap *clk;
  84
  85        clk = to_clk_hw_omap(hw);
  86
  87        if (unlikely(!clk->clkdm)) {
  88                pr_err("%s: %s: no clkdm set ?!\n", __func__,
  89                       clk_hw_get_name(hw));
  90                return;
  91        }
  92
  93        if (unlikely(clk->enable_reg))
  94                pr_err("%s: %s: should use dflt_clk_disable ?!\n", __func__,
  95                       clk_hw_get_name(hw));
  96
  97        if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
  98                pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
  99                       __func__, clk_hw_get_name(hw));
 100                return;
 101        }
 102
 103        ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
 104}
 105
 106static void __init of_ti_clockdomain_setup(struct device_node *node)
 107{
 108        struct clk *clk;
 109        struct clk_hw *clk_hw;
 110        const char *clkdm_name = node->name;
 111        int i;
 112        unsigned int num_clks;
 113
 114        num_clks = of_clk_get_parent_count(node);
 115
 116        for (i = 0; i < num_clks; i++) {
 117                clk = of_clk_get(node, i);
 118                if (IS_ERR(clk)) {
 119                        pr_err("%s: Failed get %s' clock nr %d (%ld)\n",
 120                               __func__, node->full_name, i, PTR_ERR(clk));
 121                        continue;
 122                }
 123                clk_hw = __clk_get_hw(clk);
 124                if (clk_hw_get_flags(clk_hw) & CLK_IS_BASIC) {
 125                        pr_warn("can't setup clkdm for basic clk %s\n",
 126                                __clk_get_name(clk));
 127                        continue;
 128                }
 129                to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
 130                omap2_init_clk_clkdm(clk_hw);
 131        }
 132}
 133
 134static const struct of_device_id ti_clkdm_match_table[] __initconst = {
 135        { .compatible = "ti,clockdomain" },
 136        { }
 137};
 138
 139/**
 140 * ti_dt_clockdomains_setup - setup device tree clockdomains
 141 *
 142 * Initializes clockdomain nodes for a SoC. This parses through all the
 143 * nodes with compatible = "ti,clockdomain", and add the clockdomain
 144 * info for all the clocks listed under these. This function shall be
 145 * called after rest of the DT clock init has completed and all
 146 * clock nodes have been registered.
 147 */
 148void __init ti_dt_clockdomains_setup(void)
 149{
 150        struct device_node *np;
 151        for_each_matching_node(np, ti_clkdm_match_table) {
 152                of_ti_clockdomain_setup(np);
 153        }
 154}
 155
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