1 /* 2 * TI clock 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-provider.h> 19 #include <linux/clkdev.h> 20 #include <linux/clk/ti.h> 21 #include <linux/of.h> 22 #include <linux/of_address.h> 23 #include <linux/list.h> 24 25 #undef pr_fmt 26 #define pr_fmt(fmt) "%s: " fmt, __func__ 27 28 struct ti_clk_ll_ops *ti_clk_ll_ops; 29 static struct device_node *clocks_node_ptr[CLK_MAX_MEMMAPS]; 30 31 /** 32 * ti_dt_clocks_register - register DT alias clocks during boot 33 * @oclks: list of clocks to register 34 * 35 * Register alias or non-standard DT clock entries during boot. By 36 * default, DT clocks are found based on their node name. If any 37 * additional con-id / dev-id -> clock mapping is required, use this 38 * function to list these. 39 */ 40 void __init ti_dt_clocks_register(struct ti_dt_clk oclks[]) 41 { 42 struct ti_dt_clk *c; 43 struct device_node *node; 44 struct clk *clk; 45 struct of_phandle_args clkspec; 46 47 for (c = oclks; c->node_name != NULL; c++) { 48 node = of_find_node_by_name(NULL, c->node_name); 49 clkspec.np = node; 50 clk = of_clk_get_from_provider(&clkspec); 51 52 if (!IS_ERR(clk)) { 53 c->lk.clk = clk; 54 clkdev_add(&c->lk); 55 } else { 56 pr_warn("failed to lookup clock node %s\n", 57 c->node_name); 58 } 59 } 60 } 61 62 struct clk_init_item { 63 struct device_node *node; 64 struct clk_hw *hw; 65 ti_of_clk_init_cb_t func; 66 struct list_head link; 67 }; 68 69 static LIST_HEAD(retry_list); 70 71 /** 72 * ti_clk_retry_init - retries a failed clock init at later phase 73 * @node: device not for the clock 74 * @hw: partially initialized clk_hw struct for the clock 75 * @func: init function to be called for the clock 76 * 77 * Adds a failed clock init to the retry list. The retry list is parsed 78 * once all the other clocks have been initialized. 79 */ 80 int __init ti_clk_retry_init(struct device_node *node, struct clk_hw *hw, 81 ti_of_clk_init_cb_t func) 82 { 83 struct clk_init_item *retry; 84 85 pr_debug("%s: adding to retry list...\n", node->name); 86 retry = kzalloc(sizeof(*retry), GFP_KERNEL); 87 if (!retry) 88 return -ENOMEM; 89 90 retry->node = node; 91 retry->func = func; 92 retry->hw = hw; 93 list_add(&retry->link, &retry_list); 94 95 return 0; 96 } 97 98 /** 99 * ti_clk_get_reg_addr - get register address for a clock register 100 * @node: device node for the clock 101 * @index: register index from the clock node 102 * 103 * Builds clock register address from device tree information. This 104 * is a struct of type clk_omap_reg. 105 */ 106 void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index) 107 { 108 struct clk_omap_reg *reg; 109 u32 val; 110 u32 tmp; 111 int i; 112 113 reg = (struct clk_omap_reg *)&tmp; 114 115 for (i = 0; i < CLK_MAX_MEMMAPS; i++) { 116 if (clocks_node_ptr[i] == node->parent) 117 break; 118 } 119 120 if (i == CLK_MAX_MEMMAPS) { 121 pr_err("clk-provider not found for %s!\n", node->name); 122 return NULL; 123 } 124 125 reg->index = i; 126 127 if (of_property_read_u32_index(node, "reg", index, &val)) { 128 pr_err("%s must have reg[%d]!\n", node->name, index); 129 return NULL; 130 } 131 132 reg->offset = val; 133 134 return (void __iomem *)tmp; 135 } 136 137 /** 138 * ti_dt_clk_init_provider - init master clock provider 139 * @parent: master node 140 * @index: internal index for clk_reg_ops 141 * 142 * Initializes a master clock IP block. This basically sets up the 143 * mapping from clocks node to the memory map index. All the clocks 144 * are then initialized through the common of_clk_init call, and the 145 * clocks will access their memory maps based on the node layout. 146 */ 147 void ti_dt_clk_init_provider(struct device_node *parent, int index) 148 { 149 struct device_node *clocks; 150 151 /* get clocks for this parent */ 152 clocks = of_get_child_by_name(parent, "clocks"); 153 if (!clocks) { 154 pr_err("%s missing 'clocks' child node.\n", parent->name); 155 return; 156 } 157 158 /* add clocks node info */ 159 clocks_node_ptr[index] = clocks; 160 } 161 162 /** 163 * ti_dt_clk_init_retry_clks - init clocks from the retry list 164 * 165 * Initializes any clocks that have failed to initialize before, 166 * reasons being missing parent node(s) during earlier init. This 167 * typically happens only for DPLLs which need to have both of their 168 * parent clocks ready during init. 169 */ 170 void ti_dt_clk_init_retry_clks(void) 171 { 172 struct clk_init_item *retry; 173 struct clk_init_item *tmp; 174 int retries = 5; 175 176 while (!list_empty(&retry_list) && retries) { 177 list_for_each_entry_safe(retry, tmp, &retry_list, link) { 178 pr_debug("retry-init: %s\n", retry->node->name); 179 retry->func(retry->hw, retry->node); 180 list_del(&retry->link); 181 kfree(retry); 182 } 183 retries--; 184 } 185 } 186