1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * 4 * Copyright (C) 2013 ARM Limited 5 */ 6 7 #include <linux/amba/sp810.h> 8 #include <linux/slab.h> 9 #include <linux/clk.h> 10 #include <linux/clk-provider.h> 11 #include <linux/err.h> 12 #include <linux/io.h> 13 #include <linux/of.h> 14 #include <linux/of_address.h> 15 16 #define to_clk_sp810_timerclken(_hw) \ 17 container_of(_hw, struct clk_sp810_timerclken, hw) 18 19 struct clk_sp810; 20 21 struct clk_sp810_timerclken { 22 struct clk_hw hw; 23 struct clk *clk; 24 struct clk_sp810 *sp810; 25 int channel; 26 }; 27 28 struct clk_sp810 { 29 struct device_node *node; 30 void __iomem *base; 31 spinlock_t lock; 32 struct clk_sp810_timerclken timerclken[4]; 33 }; 34 35 static u8 clk_sp810_timerclken_get_parent(struct clk_hw *hw) 36 { 37 struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw); 38 u32 val = readl(timerclken->sp810->base + SCCTRL); 39 40 return !!(val & (1 << SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel))); 41 } 42 43 static int clk_sp810_timerclken_set_parent(struct clk_hw *hw, u8 index) 44 { 45 struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw); 46 struct clk_sp810 *sp810 = timerclken->sp810; 47 u32 val, shift = SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel); 48 unsigned long flags = 0; 49 50 if (WARN_ON(index > 1)) 51 return -EINVAL; 52 53 spin_lock_irqsave(&sp810->lock, flags); 54 55 val = readl(sp810->base + SCCTRL); 56 val &= ~(1 << shift); 57 val |= index << shift; 58 writel(val, sp810->base + SCCTRL); 59 60 spin_unlock_irqrestore(&sp810->lock, flags); 61 62 return 0; 63 } 64 65 static const struct clk_ops clk_sp810_timerclken_ops = { 66 .determine_rate = clk_hw_determine_rate_no_reparent, 67 .get_parent = clk_sp810_timerclken_get_parent, 68 .set_parent = clk_sp810_timerclken_set_parent, 69 }; 70 71 static struct clk *clk_sp810_timerclken_of_get(struct of_phandle_args *clkspec, 72 void *data) 73 { 74 struct clk_sp810 *sp810 = data; 75 76 if (WARN_ON(clkspec->args_count != 1 || 77 clkspec->args[0] >= ARRAY_SIZE(sp810->timerclken))) 78 return NULL; 79 80 return sp810->timerclken[clkspec->args[0]].clk; 81 } 82 83 static void __init clk_sp810_of_setup(struct device_node *node) 84 { 85 struct clk_sp810 *sp810 = kzalloc(sizeof(*sp810), GFP_KERNEL); 86 const char *parent_names[2]; 87 int num = ARRAY_SIZE(parent_names); 88 char name[12]; 89 struct clk_init_data init; 90 static int instance; 91 int i; 92 bool deprecated; 93 94 if (!sp810) 95 return; 96 97 if (of_clk_parent_fill(node, parent_names, num) != num) { 98 pr_warn("Failed to obtain parent clocks for SP810!\n"); 99 kfree(sp810); 100 return; 101 } 102 103 sp810->node = node; 104 sp810->base = of_iomap(node, 0); 105 spin_lock_init(&sp810->lock); 106 107 init.name = name; 108 init.ops = &clk_sp810_timerclken_ops; 109 init.flags = 0; 110 init.parent_names = parent_names; 111 init.num_parents = num; 112 113 deprecated = !of_find_property(node, "assigned-clock-parents", NULL); 114 115 for (i = 0; i < ARRAY_SIZE(sp810->timerclken); i++) { 116 snprintf(name, sizeof(name), "sp810_%d_%d", instance, i); 117 118 sp810->timerclken[i].sp810 = sp810; 119 sp810->timerclken[i].channel = i; 120 sp810->timerclken[i].hw.init = &init; 121 122 /* 123 * If DT isn't setting the parent, force it to be 124 * the 1 MHz clock without going through the framework. 125 * We do this before clk_register() so that it can determine 126 * the parent and setup the tree properly. 127 */ 128 if (deprecated) 129 init.ops->set_parent(&sp810->timerclken[i].hw, 1); 130 131 sp810->timerclken[i].clk = clk_register(NULL, 132 &sp810->timerclken[i].hw); 133 WARN_ON(IS_ERR(sp810->timerclken[i].clk)); 134 } 135 136 of_clk_add_provider(node, clk_sp810_timerclken_of_get, sp810); 137 instance++; 138 } 139 CLK_OF_DECLARE(sp810, "arm,sp810", clk_sp810_of_setup); 140