drivers/clk/ti/clockdomain.c

   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  */
  42 int 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  */
  81 void 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
 106 static 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
 134 static 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  */
 148 void __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 }