1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Marvell Dove PMU Core PLL divider driver 4 * 5 * Cleaned up by substantially rewriting, and converted to DT by 6 * Russell King. Origin is not known. 7 */ 8 #include <linux/clk-provider.h> 9 #include <linux/delay.h> 10 #include <linux/io.h> 11 #include <linux/kernel.h> 12 #include <linux/of.h> 13 #include <linux/of_address.h> 14 15 #include "dove-divider.h" 16 17 struct dove_clk { 18 const char *name; 19 struct clk_hw hw; 20 void __iomem *base; 21 spinlock_t *lock; 22 u8 div_bit_start; 23 u8 div_bit_end; 24 u8 div_bit_load; 25 u8 div_bit_size; 26 u32 *divider_table; 27 }; 28 29 enum { 30 DIV_CTRL0 = 0, 31 DIV_CTRL1 = 4, 32 DIV_CTRL1_N_RESET_MASK = BIT(10), 33 }; 34 35 #define to_dove_clk(hw) container_of(hw, struct dove_clk, hw) 36 37 static void dove_load_divider(void __iomem *base, u32 val, u32 mask, u32 load) 38 { 39 u32 v; 40 41 v = readl_relaxed(base + DIV_CTRL1) | DIV_CTRL1_N_RESET_MASK; 42 writel_relaxed(v, base + DIV_CTRL1); 43 44 v = (readl_relaxed(base + DIV_CTRL0) & ~(mask | load)) | val; 45 writel_relaxed(v, base + DIV_CTRL0); 46 writel_relaxed(v | load, base + DIV_CTRL0); 47 ndelay(250); 48 writel_relaxed(v, base + DIV_CTRL0); 49 } 50 51 static unsigned int dove_get_divider(struct dove_clk *dc) 52 { 53 unsigned int divider; 54 u32 val; 55 56 val = readl_relaxed(dc->base + DIV_CTRL0); 57 val >>= dc->div_bit_start; 58 59 divider = val & ~(~0 << dc->div_bit_size); 60 61 if (dc->divider_table) 62 divider = dc->divider_table[divider]; 63 64 return divider; 65 } 66 67 static int dove_calc_divider(const struct dove_clk *dc, unsigned long rate, 68 unsigned long parent_rate, bool set) 69 { 70 unsigned int divider, max; 71 72 divider = DIV_ROUND_CLOSEST(parent_rate, rate); 73 74 if (dc->divider_table) { 75 unsigned int i; 76 77 for (i = 0; dc->divider_table[i]; i++) 78 if (divider == dc->divider_table[i]) { 79 divider = i; 80 break; 81 } 82 83 if (!dc->divider_table[i]) 84 return -EINVAL; 85 } else { 86 max = 1 << dc->div_bit_size; 87 88 if (set && (divider == 0 || divider >= max)) 89 return -EINVAL; 90 if (divider >= max) 91 divider = max - 1; 92 else if (divider == 0) 93 divider = 1; 94 } 95 96 return divider; 97 } 98 99 static unsigned long dove_recalc_rate(struct clk_hw *hw, unsigned long parent) 100 { 101 struct dove_clk *dc = to_dove_clk(hw); 102 unsigned int divider = dove_get_divider(dc); 103 unsigned long rate = DIV_ROUND_CLOSEST(parent, divider); 104 105 pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n", 106 __func__, dc->name, divider, parent, rate); 107 108 return rate; 109 } 110 111 static long dove_round_rate(struct clk_hw *hw, unsigned long rate, 112 unsigned long *parent) 113 { 114 struct dove_clk *dc = to_dove_clk(hw); 115 unsigned long parent_rate = *parent; 116 int divider; 117 118 divider = dove_calc_divider(dc, rate, parent_rate, false); 119 if (divider < 0) 120 return divider; 121 122 rate = DIV_ROUND_CLOSEST(parent_rate, divider); 123 124 pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n", 125 __func__, dc->name, divider, parent_rate, rate); 126 127 return rate; 128 } 129 130 static int dove_set_clock(struct clk_hw *hw, unsigned long rate, 131 unsigned long parent_rate) 132 { 133 struct dove_clk *dc = to_dove_clk(hw); 134 u32 mask, load, div; 135 int divider; 136 137 divider = dove_calc_divider(dc, rate, parent_rate, true); 138 if (divider < 0) 139 return divider; 140 141 pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n", 142 __func__, dc->name, divider, parent_rate, rate); 143 144 div = (u32)divider << dc->div_bit_start; 145 mask = ~(~0 << dc->div_bit_size) << dc->div_bit_start; 146 load = BIT(dc->div_bit_load); 147 148 spin_lock(dc->lock); 149 dove_load_divider(dc->base, div, mask, load); 150 spin_unlock(dc->lock); 151 152 return 0; 153 } 154 155 static const struct clk_ops dove_divider_ops = { 156 .set_rate = dove_set_clock, 157 .round_rate = dove_round_rate, 158 .recalc_rate = dove_recalc_rate, 159 }; 160 161 static struct clk *clk_register_dove_divider(struct device *dev, 162 struct dove_clk *dc, const char **parent_names, size_t num_parents, 163 void __iomem *base) 164 { 165 char name[32]; 166 struct clk_init_data init = { 167 .name = name, 168 .ops = &dove_divider_ops, 169 .parent_names = parent_names, 170 .num_parents = num_parents, 171 }; 172 173 strscpy(name, dc->name, sizeof(name)); 174 175 dc->hw.init = &init; 176 dc->base = base; 177 dc->div_bit_size = dc->div_bit_end - dc->div_bit_start + 1; 178 179 return clk_register(dev, &dc->hw); 180 } 181 182 static DEFINE_SPINLOCK(dove_divider_lock); 183 184 static u32 axi_divider[] = {-1, 2, 1, 3, 4, 6, 5, 7, 8, 10, 9, 0}; 185 186 static struct dove_clk dove_hw_clocks[4] = { 187 { 188 .name = "axi", 189 .lock = &dove_divider_lock, 190 .div_bit_start = 1, 191 .div_bit_end = 6, 192 .div_bit_load = 7, 193 .divider_table = axi_divider, 194 }, { 195 .name = "gpu", 196 .lock = &dove_divider_lock, 197 .div_bit_start = 8, 198 .div_bit_end = 13, 199 .div_bit_load = 14, 200 }, { 201 .name = "vmeta", 202 .lock = &dove_divider_lock, 203 .div_bit_start = 15, 204 .div_bit_end = 20, 205 .div_bit_load = 21, 206 }, { 207 .name = "lcd", 208 .lock = &dove_divider_lock, 209 .div_bit_start = 22, 210 .div_bit_end = 27, 211 .div_bit_load = 28, 212 }, 213 }; 214 215 static const char *core_pll[] = { 216 "core-pll", 217 }; 218 219 static int dove_divider_init(struct device *dev, void __iomem *base, 220 struct clk **clks) 221 { 222 struct clk *clk; 223 int i; 224 225 /* 226 * Create the core PLL clock. We treat this as a fixed rate 227 * clock as we don't know any better, and documentation is sparse. 228 */ 229 clk = clk_register_fixed_rate(dev, core_pll[0], NULL, 0, 2000000000UL); 230 if (IS_ERR(clk)) 231 return PTR_ERR(clk); 232 233 for (i = 0; i < ARRAY_SIZE(dove_hw_clocks); i++) 234 clks[i] = clk_register_dove_divider(dev, &dove_hw_clocks[i], 235 core_pll, 236 ARRAY_SIZE(core_pll), base); 237 238 return 0; 239 } 240 241 static struct clk *dove_divider_clocks[4]; 242 243 static struct clk_onecell_data dove_divider_data = { 244 .clks = dove_divider_clocks, 245 .clk_num = ARRAY_SIZE(dove_divider_clocks), 246 }; 247 248 void __init dove_divider_clk_init(struct device_node *np) 249 { 250 void __iomem *base; 251 252 base = of_iomap(np, 0); 253 if (WARN_ON(!base)) 254 return; 255 256 if (WARN_ON(dove_divider_init(NULL, base, dove_divider_clocks))) { 257 iounmap(base); 258 return; 259 } 260 261 of_clk_add_provider(np, of_clk_src_onecell_get, &dove_divider_data); 262 } 263