1 /* 2 * Copyright 2012 Freescale Semiconductor, Inc. 3 * Copyright 2012 Linaro Ltd. 4 * 5 * The code contained herein is licensed under the GNU General Public 6 * License. You may obtain a copy of the GNU General Public License 7 * Version 2 or later at the following locations: 8 * 9 * http://www.opensource.org/licenses/gpl-license.html 10 * http://www.gnu.org/copyleft/gpl.html 11 */ 12 13 #include <linux/clk.h> 14 #include <linux/clk-provider.h> 15 #include <linux/io.h> 16 #include <linux/slab.h> 17 #include <linux/jiffies.h> 18 #include <linux/err.h> 19 #include "clk.h" 20 21 static int clk_busy_wait(void __iomem *reg, u8 shift) 22 { 23 unsigned long timeout = jiffies + msecs_to_jiffies(10); 24 25 while (readl_relaxed(reg) & (1 << shift)) 26 if (time_after(jiffies, timeout)) 27 return -ETIMEDOUT; 28 29 return 0; 30 } 31 32 struct clk_busy_divider { 33 struct clk_divider div; 34 const struct clk_ops *div_ops; 35 void __iomem *reg; 36 u8 shift; 37 }; 38 39 static inline struct clk_busy_divider *to_clk_busy_divider(struct clk_hw *hw) 40 { 41 struct clk_divider *div = to_clk_divider(hw); 42 43 return container_of(div, struct clk_busy_divider, div); 44 } 45 46 static unsigned long clk_busy_divider_recalc_rate(struct clk_hw *hw, 47 unsigned long parent_rate) 48 { 49 struct clk_busy_divider *busy = to_clk_busy_divider(hw); 50 51 return busy->div_ops->recalc_rate(&busy->div.hw, parent_rate); 52 } 53 54 static long clk_busy_divider_round_rate(struct clk_hw *hw, unsigned long rate, 55 unsigned long *prate) 56 { 57 struct clk_busy_divider *busy = to_clk_busy_divider(hw); 58 59 return busy->div_ops->round_rate(&busy->div.hw, rate, prate); 60 } 61 62 static int clk_busy_divider_set_rate(struct clk_hw *hw, unsigned long rate, 63 unsigned long parent_rate) 64 { 65 struct clk_busy_divider *busy = to_clk_busy_divider(hw); 66 int ret; 67 68 ret = busy->div_ops->set_rate(&busy->div.hw, rate, parent_rate); 69 if (!ret) 70 ret = clk_busy_wait(busy->reg, busy->shift); 71 72 return ret; 73 } 74 75 static const struct clk_ops clk_busy_divider_ops = { 76 .recalc_rate = clk_busy_divider_recalc_rate, 77 .round_rate = clk_busy_divider_round_rate, 78 .set_rate = clk_busy_divider_set_rate, 79 }; 80 81 struct clk *imx_clk_busy_divider(const char *name, const char *parent_name, 82 void __iomem *reg, u8 shift, u8 width, 83 void __iomem *busy_reg, u8 busy_shift) 84 { 85 struct clk_busy_divider *busy; 86 struct clk *clk; 87 struct clk_init_data init; 88 89 busy = kzalloc(sizeof(*busy), GFP_KERNEL); 90 if (!busy) 91 return ERR_PTR(-ENOMEM); 92 93 busy->reg = busy_reg; 94 busy->shift = busy_shift; 95 96 busy->div.reg = reg; 97 busy->div.shift = shift; 98 busy->div.width = width; 99 busy->div.lock = &imx_ccm_lock; 100 busy->div_ops = &clk_divider_ops; 101 102 init.name = name; 103 init.ops = &clk_busy_divider_ops; 104 init.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL; 105 init.parent_names = &parent_name; 106 init.num_parents = 1; 107 108 busy->div.hw.init = &init; 109 110 clk = clk_register(NULL, &busy->div.hw); 111 if (IS_ERR(clk)) 112 kfree(busy); 113 114 return clk; 115 } 116 117 struct clk_busy_mux { 118 struct clk_mux mux; 119 const struct clk_ops *mux_ops; 120 void __iomem *reg; 121 u8 shift; 122 }; 123 124 static inline struct clk_busy_mux *to_clk_busy_mux(struct clk_hw *hw) 125 { 126 struct clk_mux *mux = to_clk_mux(hw); 127 128 return container_of(mux, struct clk_busy_mux, mux); 129 } 130 131 static u8 clk_busy_mux_get_parent(struct clk_hw *hw) 132 { 133 struct clk_busy_mux *busy = to_clk_busy_mux(hw); 134 135 return busy->mux_ops->get_parent(&busy->mux.hw); 136 } 137 138 static int clk_busy_mux_set_parent(struct clk_hw *hw, u8 index) 139 { 140 struct clk_busy_mux *busy = to_clk_busy_mux(hw); 141 int ret; 142 143 ret = busy->mux_ops->set_parent(&busy->mux.hw, index); 144 if (!ret) 145 ret = clk_busy_wait(busy->reg, busy->shift); 146 147 return ret; 148 } 149 150 static const struct clk_ops clk_busy_mux_ops = { 151 .get_parent = clk_busy_mux_get_parent, 152 .set_parent = clk_busy_mux_set_parent, 153 }; 154 155 struct clk *imx_clk_busy_mux(const char *name, void __iomem *reg, u8 shift, 156 u8 width, void __iomem *busy_reg, u8 busy_shift, 157 const char * const *parent_names, int num_parents) 158 { 159 struct clk_busy_mux *busy; 160 struct clk *clk; 161 struct clk_init_data init; 162 163 busy = kzalloc(sizeof(*busy), GFP_KERNEL); 164 if (!busy) 165 return ERR_PTR(-ENOMEM); 166 167 busy->reg = busy_reg; 168 busy->shift = busy_shift; 169 170 busy->mux.reg = reg; 171 busy->mux.shift = shift; 172 busy->mux.mask = BIT(width) - 1; 173 busy->mux.lock = &imx_ccm_lock; 174 busy->mux_ops = &clk_mux_ops; 175 176 init.name = name; 177 init.ops = &clk_busy_mux_ops; 178 init.flags = CLK_IS_CRITICAL; 179 init.parent_names = parent_names; 180 init.num_parents = num_parents; 181 182 busy->mux.hw.init = &init; 183 184 clk = clk_register(NULL, &busy->mux.hw); 185 if (IS_ERR(clk)) 186 kfree(busy); 187 188 return clk; 189 } 190