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 (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
  56                 pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
  57                        __func__, clk_hw_get_name(hw));
  58                 return 0;
  59         }
  60
  61         ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
  62         WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
  63              __func__, clk_hw_get_name(hw), clk->clkdm_name, ret);
  64
  65         return ret;
  66 }
  67
  68 /**
  69  * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
  70  * @hw: struct clk_hw * of the clock being disabled
  71  *
  72  * Decrement the usecount of the clockdomain of the clock pointed to
  73  * by @hw; if the usecount is 0, the clockdomain will be "disabled."
  74  * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
  75  * disable function pointer.  No return value.
  76  */
  77 void omap2_clkops_disable_clkdm(struct clk_hw *hw)
  78 {
  79         struct clk_hw_omap *clk;
  80
  81         clk = to_clk_hw_omap(hw);
  82
  83         if (unlikely(!clk->clkdm)) {
  84                 pr_err("%s: %s: no clkdm set ?!\n", __func__,
  85                        clk_hw_get_name(hw));
  86                 return;
  87         }
  88
  89         if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
  90                 pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
  91                        __func__, clk_hw_get_name(hw));
  92                 return;
  93         }
  94
  95         ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
  96 }
  97
  98 /**
  99  * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
 100  * @clk: OMAP clock struct ptr to use
 101  *
 102  * Convert a clockdomain name stored in a struct clk 'clk' into a
 103  * clockdomain pointer, and save it into the struct clk.  Intended to be
 104  * called during clk_register(). Returns 0 on success, -EERROR otherwise.
 105  */
 106 int omap2_init_clk_clkdm(struct clk_hw *hw)
 107 {
 108         struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 109         struct clockdomain *clkdm;
 110         const char *clk_name;
 111
 112         if (!clk->clkdm_name)
 113                 return 0;
 114
 115         clk_name = __clk_get_name(hw->clk);
 116
 117         clkdm = ti_clk_ll_ops->clkdm_lookup(clk->clkdm_name);
 118         if (clkdm) {
 119                 pr_debug("clock: associated clk %s to clkdm %s\n",
 120                          clk_name, clk->clkdm_name);
 121                 clk->clkdm = clkdm;
 122         } else {
 123                 pr_debug("clock: could not associate clk %s to clkdm %s\n",
 124                          clk_name, clk->clkdm_name);
 125         }
 126
 127         return 0;
 128 }
 129
 130 static void __init of_ti_clockdomain_setup(struct device_node *node)
 131 {
 132         struct clk *clk;
 133         struct clk_hw *clk_hw;
 134         const char *clkdm_name = node->name;
 135         int i;
 136         unsigned int num_clks;
 137
 138         num_clks = of_clk_get_parent_count(node);
 139
 140         for (i = 0; i < num_clks; i++) {
 141                 clk = of_clk_get(node, i);
 142                 if (IS_ERR(clk)) {
 143                         pr_err("%s: Failed get %pOF' clock nr %d (%ld)\n",
 144                                __func__, node, i, PTR_ERR(clk));
 145                         continue;
 146                 }
 147                 clk_hw = __clk_get_hw(clk);
 148                 if (!omap2_clk_is_hw_omap(clk_hw)) {
 149                         pr_warn("can't setup clkdm for basic clk %s\n",
 150                                 __clk_get_name(clk));
 151                         clk_put(clk);
 152                         continue;
 153                 }
 154                 to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
 155                 omap2_init_clk_clkdm(clk_hw);
 156                 clk_put(clk);
 157         }
 158 }
 159
 160 static const struct of_device_id ti_clkdm_match_table[] __initconst = {
 161         { .compatible = "ti,clockdomain" },
 162         { }
 163 };
 164
 165 /**
 166  * ti_dt_clockdomains_setup - setup device tree clockdomains
 167  *
 168  * Initializes clockdomain nodes for a SoC. This parses through all the
 169  * nodes with compatible = "ti,clockdomain", and add the clockdomain
 170  * info for all the clocks listed under these. This function shall be
 171  * called after rest of the DT clock init has completed and all
 172  * clock nodes have been registered.
 173  */
 174 void __init ti_dt_clockdomains_setup(void)
 175 {
 176         struct device_node *np;
 177         for_each_matching_node(np, ti_clkdm_match_table) {
 178                 of_ti_clockdomain_setup(np);
 179         }
 180 }