1 /* 2 * Copyright 2014 Chen-Yu Tsai 3 * 4 * Chen-Yu Tsai <wens@csie.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/clk.h> 18 #include <linux/clk-provider.h> 19 #include <linux/slab.h> 20 #include <linux/spinlock.h> 21 #include <linux/of_address.h> 22 23 #define SUN8I_MBUS_ENABLE 31 24 #define SUN8I_MBUS_MUX_SHIFT 24 25 #define SUN8I_MBUS_MUX_MASK 0x3 26 #define SUN8I_MBUS_DIV_SHIFT 0 27 #define SUN8I_MBUS_DIV_WIDTH 3 28 #define SUN8I_MBUS_MAX_PARENTS 4 29 30 static DEFINE_SPINLOCK(sun8i_a23_mbus_lock); 31 32 static void __init sun8i_a23_mbus_setup(struct device_node *node) 33 { 34 int num_parents = of_clk_get_parent_count(node); 35 const char **parents; 36 const char *clk_name = node->name; 37 struct resource res; 38 struct clk_divider *div; 39 struct clk_gate *gate; 40 struct clk_mux *mux; 41 struct clk *clk; 42 void __iomem *reg; 43 int err; 44 45 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL); 46 if (!parents) 47 return; 48 49 reg = of_io_request_and_map(node, 0, of_node_full_name(node)); 50 if (IS_ERR(reg)) { 51 pr_err("Could not get registers for sun8i-mbus-clk\n"); 52 goto err_free_parents; 53 } 54 55 div = kzalloc(sizeof(*div), GFP_KERNEL); 56 if (!div) 57 goto err_unmap; 58 59 mux = kzalloc(sizeof(*mux), GFP_KERNEL); 60 if (!mux) 61 goto err_free_div; 62 63 gate = kzalloc(sizeof(*gate), GFP_KERNEL); 64 if (!gate) 65 goto err_free_mux; 66 67 of_property_read_string(node, "clock-output-names", &clk_name); 68 of_clk_parent_fill(node, parents, num_parents); 69 70 gate->reg = reg; 71 gate->bit_idx = SUN8I_MBUS_ENABLE; 72 gate->lock = &sun8i_a23_mbus_lock; 73 74 div->reg = reg; 75 div->shift = SUN8I_MBUS_DIV_SHIFT; 76 div->width = SUN8I_MBUS_DIV_WIDTH; 77 div->lock = &sun8i_a23_mbus_lock; 78 79 mux->reg = reg; 80 mux->shift = SUN8I_MBUS_MUX_SHIFT; 81 mux->mask = SUN8I_MBUS_MUX_MASK; 82 mux->lock = &sun8i_a23_mbus_lock; 83 84 /* The MBUS clocks needs to be always enabled */ 85 clk = clk_register_composite(NULL, clk_name, parents, num_parents, 86 &mux->hw, &clk_mux_ops, 87 &div->hw, &clk_divider_ops, 88 &gate->hw, &clk_gate_ops, 89 CLK_IS_CRITICAL); 90 if (IS_ERR(clk)) 91 goto err_free_gate; 92 93 err = of_clk_add_provider(node, of_clk_src_simple_get, clk); 94 if (err) 95 goto err_unregister_clk; 96 97 kfree(parents); /* parents is deep copied */ 98 99 return; 100 101 err_unregister_clk: 102 /* TODO: The composite clock stuff will leak a bit here. */ 103 clk_unregister(clk); 104 err_free_gate: 105 kfree(gate); 106 err_free_mux: 107 kfree(mux); 108 err_free_div: 109 kfree(div); 110 err_unmap: 111 iounmap(reg); 112 of_address_to_resource(node, 0, &res); 113 release_mem_region(res.start, resource_size(&res)); 114 err_free_parents: 115 kfree(parents); 116 } 117 CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup); 118