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(). No return value. 105 */ 106 void 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; 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 } 127 128 static void __init of_ti_clockdomain_setup(struct device_node *node) 129 { 130 struct clk *clk; 131 struct clk_hw *clk_hw; 132 const char *clkdm_name = node->name; 133 int i; 134 unsigned int num_clks; 135 136 num_clks = of_clk_get_parent_count(node); 137 138 for (i = 0; i < num_clks; i++) { 139 clk = of_clk_get(node, i); 140 if (IS_ERR(clk)) { 141 pr_err("%s: Failed get %pOF' clock nr %d (%ld)\n", 142 __func__, node, i, PTR_ERR(clk)); 143 continue; 144 } 145 clk_hw = __clk_get_hw(clk); 146 if (clk_hw_get_flags(clk_hw) & CLK_IS_BASIC) { 147 pr_warn("can't setup clkdm for basic clk %s\n", 148 __clk_get_name(clk)); 149 continue; 150 } 151 to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name; 152 omap2_init_clk_clkdm(clk_hw); 153 } 154 } 155 156 static const struct of_device_id ti_clkdm_match_table[] __initconst = { 157 { .compatible = "ti,clockdomain" }, 158 { } 159 }; 160 161 /** 162 * ti_dt_clockdomains_setup - setup device tree clockdomains 163 * 164 * Initializes clockdomain nodes for a SoC. This parses through all the 165 * nodes with compatible = "ti,clockdomain", and add the clockdomain 166 * info for all the clocks listed under these. This function shall be 167 * called after rest of the DT clock init has completed and all 168 * clock nodes have been registered. 169 */ 170 void __init ti_dt_clockdomains_setup(void) 171 { 172 struct device_node *np; 173 for_each_matching_node(np, ti_clkdm_match_table) { 174 of_ti_clockdomain_setup(np); 175 } 176 } 177