1 /* 2 * Copyright (c) 2014 MediaTek Inc. 3 * Author: James Liao <jamesjj.liao@mediatek.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/of.h> 16 #include <linux/of_address.h> 17 #include <linux/io.h> 18 #include <linux/slab.h> 19 #include <linux/clkdev.h> 20 #include <linux/delay.h> 21 22 #include "clk-mtk.h" 23 24 #define REG_CON0 0 25 #define REG_CON1 4 26 27 #define CON0_BASE_EN BIT(0) 28 #define CON0_PWR_ON BIT(0) 29 #define CON0_ISO_EN BIT(1) 30 #define CON0_PCW_CHG BIT(31) 31 32 #define AUDPLL_TUNER_EN BIT(31) 33 34 #define POSTDIV_MASK 0x7 35 #define INTEGER_BITS 7 36 37 /* 38 * MediaTek PLLs are configured through their pcw value. The pcw value describes 39 * a divider in the PLL feedback loop which consists of 7 bits for the integer 40 * part and the remaining bits (if present) for the fractional part. Also they 41 * have a 3 bit power-of-two post divider. 42 */ 43 44 struct mtk_clk_pll { 45 struct clk_hw hw; 46 void __iomem *base_addr; 47 void __iomem *pd_addr; 48 void __iomem *pwr_addr; 49 void __iomem *tuner_addr; 50 void __iomem *pcw_addr; 51 const struct mtk_pll_data *data; 52 }; 53 54 static inline struct mtk_clk_pll *to_mtk_clk_pll(struct clk_hw *hw) 55 { 56 return container_of(hw, struct mtk_clk_pll, hw); 57 } 58 59 static int mtk_pll_is_prepared(struct clk_hw *hw) 60 { 61 struct mtk_clk_pll *pll = to_mtk_clk_pll(hw); 62 63 return (readl(pll->base_addr + REG_CON0) & CON0_BASE_EN) != 0; 64 } 65 66 static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin, 67 u32 pcw, int postdiv) 68 { 69 int pcwbits = pll->data->pcwbits; 70 int pcwfbits; 71 u64 vco; 72 u8 c = 0; 73 74 /* The fractional part of the PLL divider. */ 75 pcwfbits = pcwbits > INTEGER_BITS ? pcwbits - INTEGER_BITS : 0; 76 77 vco = (u64)fin * pcw; 78 79 if (pcwfbits && (vco & GENMASK(pcwfbits - 1, 0))) 80 c = 1; 81 82 vco >>= pcwfbits; 83 84 if (c) 85 vco++; 86 87 return ((unsigned long)vco + postdiv - 1) / postdiv; 88 } 89 90 static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw, 91 int postdiv) 92 { 93 u32 con1, val; 94 int pll_en; 95 96 pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN; 97 98 /* set postdiv */ 99 val = readl(pll->pd_addr); 100 val &= ~(POSTDIV_MASK << pll->data->pd_shift); 101 val |= (ffs(postdiv) - 1) << pll->data->pd_shift; 102 103 /* postdiv and pcw need to set at the same time if on same register */ 104 if (pll->pd_addr != pll->pcw_addr) { 105 writel(val, pll->pd_addr); 106 val = readl(pll->pcw_addr); 107 } 108 109 /* set pcw */ 110 val &= ~GENMASK(pll->data->pcw_shift + pll->data->pcwbits - 1, 111 pll->data->pcw_shift); 112 val |= pcw << pll->data->pcw_shift; 113 writel(val, pll->pcw_addr); 114 115 con1 = readl(pll->base_addr + REG_CON1); 116 117 if (pll_en) 118 con1 |= CON0_PCW_CHG; 119 120 writel(con1, pll->base_addr + REG_CON1); 121 if (pll->tuner_addr) 122 writel(con1 + 1, pll->tuner_addr); 123 124 if (pll_en) 125 udelay(20); 126 } 127 128 /* 129 * mtk_pll_calc_values - calculate good values for a given input frequency. 130 * @pll: The pll 131 * @pcw: The pcw value (output) 132 * @postdiv: The post divider (output) 133 * @freq: The desired target frequency 134 * @fin: The input frequency 135 * 136 */ 137 static void mtk_pll_calc_values(struct mtk_clk_pll *pll, u32 *pcw, u32 *postdiv, 138 u32 freq, u32 fin) 139 { 140 unsigned long fmin = 1000 * MHZ; 141 const struct mtk_pll_div_table *div_table = pll->data->div_table; 142 u64 _pcw; 143 u32 val; 144 145 if (freq > pll->data->fmax) 146 freq = pll->data->fmax; 147 148 if (div_table) { 149 if (freq > div_table[0].freq) 150 freq = div_table[0].freq; 151 152 for (val = 0; div_table[val + 1].freq != 0; val++) { 153 if (freq > div_table[val + 1].freq) 154 break; 155 } 156 *postdiv = 1 << val; 157 } else { 158 for (val = 0; val < 5; val++) { 159 *postdiv = 1 << val; 160 if ((u64)freq * *postdiv >= fmin) 161 break; 162 } 163 } 164 165 /* _pcw = freq * postdiv / fin * 2^pcwfbits */ 166 _pcw = ((u64)freq << val) << (pll->data->pcwbits - INTEGER_BITS); 167 do_div(_pcw, fin); 168 169 *pcw = (u32)_pcw; 170 } 171 172 static int mtk_pll_set_rate(struct clk_hw *hw, unsigned long rate, 173 unsigned long parent_rate) 174 { 175 struct mtk_clk_pll *pll = to_mtk_clk_pll(hw); 176 u32 pcw = 0; 177 u32 postdiv; 178 179 mtk_pll_calc_values(pll, &pcw, &postdiv, rate, parent_rate); 180 mtk_pll_set_rate_regs(pll, pcw, postdiv); 181 182 return 0; 183 } 184 185 static unsigned long mtk_pll_recalc_rate(struct clk_hw *hw, 186 unsigned long parent_rate) 187 { 188 struct mtk_clk_pll *pll = to_mtk_clk_pll(hw); 189 u32 postdiv; 190 u32 pcw; 191 192 postdiv = (readl(pll->pd_addr) >> pll->data->pd_shift) & POSTDIV_MASK; 193 postdiv = 1 << postdiv; 194 195 pcw = readl(pll->pcw_addr) >> pll->data->pcw_shift; 196 pcw &= GENMASK(pll->data->pcwbits - 1, 0); 197 198 return __mtk_pll_recalc_rate(pll, parent_rate, pcw, postdiv); 199 } 200 201 static long mtk_pll_round_rate(struct clk_hw *hw, unsigned long rate, 202 unsigned long *prate) 203 { 204 struct mtk_clk_pll *pll = to_mtk_clk_pll(hw); 205 u32 pcw = 0; 206 int postdiv; 207 208 mtk_pll_calc_values(pll, &pcw, &postdiv, rate, *prate); 209 210 return __mtk_pll_recalc_rate(pll, *prate, pcw, postdiv); 211 } 212 213 static int mtk_pll_prepare(struct clk_hw *hw) 214 { 215 struct mtk_clk_pll *pll = to_mtk_clk_pll(hw); 216 u32 r; 217 218 r = readl(pll->pwr_addr) | CON0_PWR_ON; 219 writel(r, pll->pwr_addr); 220 udelay(1); 221 222 r = readl(pll->pwr_addr) & ~CON0_ISO_EN; 223 writel(r, pll->pwr_addr); 224 udelay(1); 225 226 r = readl(pll->base_addr + REG_CON0); 227 r |= pll->data->en_mask; 228 writel(r, pll->base_addr + REG_CON0); 229 230 if (pll->tuner_addr) { 231 r = readl(pll->tuner_addr) | AUDPLL_TUNER_EN; 232 writel(r, pll->tuner_addr); 233 } 234 235 udelay(20); 236 237 if (pll->data->flags & HAVE_RST_BAR) { 238 r = readl(pll->base_addr + REG_CON0); 239 r |= pll->data->rst_bar_mask; 240 writel(r, pll->base_addr + REG_CON0); 241 } 242 243 return 0; 244 } 245 246 static void mtk_pll_unprepare(struct clk_hw *hw) 247 { 248 struct mtk_clk_pll *pll = to_mtk_clk_pll(hw); 249 u32 r; 250 251 if (pll->data->flags & HAVE_RST_BAR) { 252 r = readl(pll->base_addr + REG_CON0); 253 r &= ~pll->data->rst_bar_mask; 254 writel(r, pll->base_addr + REG_CON0); 255 } 256 257 if (pll->tuner_addr) { 258 r = readl(pll->tuner_addr) & ~AUDPLL_TUNER_EN; 259 writel(r, pll->tuner_addr); 260 } 261 262 r = readl(pll->base_addr + REG_CON0); 263 r &= ~CON0_BASE_EN; 264 writel(r, pll->base_addr + REG_CON0); 265 266 r = readl(pll->pwr_addr) | CON0_ISO_EN; 267 writel(r, pll->pwr_addr); 268 269 r = readl(pll->pwr_addr) & ~CON0_PWR_ON; 270 writel(r, pll->pwr_addr); 271 } 272 273 static const struct clk_ops mtk_pll_ops = { 274 .is_prepared = mtk_pll_is_prepared, 275 .prepare = mtk_pll_prepare, 276 .unprepare = mtk_pll_unprepare, 277 .recalc_rate = mtk_pll_recalc_rate, 278 .round_rate = mtk_pll_round_rate, 279 .set_rate = mtk_pll_set_rate, 280 }; 281 282 static struct clk *mtk_clk_register_pll(const struct mtk_pll_data *data, 283 void __iomem *base) 284 { 285 struct mtk_clk_pll *pll; 286 struct clk_init_data init = {}; 287 struct clk *clk; 288 const char *parent_name = "clk26m"; 289 290 pll = kzalloc(sizeof(*pll), GFP_KERNEL); 291 if (!pll) 292 return ERR_PTR(-ENOMEM); 293 294 pll->base_addr = base + data->reg; 295 pll->pwr_addr = base + data->pwr_reg; 296 pll->pd_addr = base + data->pd_reg; 297 pll->pcw_addr = base + data->pcw_reg; 298 if (data->tuner_reg) 299 pll->tuner_addr = base + data->tuner_reg; 300 pll->hw.init = &init; 301 pll->data = data; 302 303 init.name = data->name; 304 init.flags = (data->flags & PLL_AO) ? CLK_IS_CRITICAL : 0; 305 init.ops = &mtk_pll_ops; 306 init.parent_names = &parent_name; 307 init.num_parents = 1; 308 309 clk = clk_register(NULL, &pll->hw); 310 311 if (IS_ERR(clk)) 312 kfree(pll); 313 314 return clk; 315 } 316 317 void mtk_clk_register_plls(struct device_node *node, 318 const struct mtk_pll_data *plls, int num_plls, struct clk_onecell_data *clk_data) 319 { 320 void __iomem *base; 321 int i; 322 struct clk *clk; 323 324 base = of_iomap(node, 0); 325 if (!base) { 326 pr_err("%s(): ioremap failed\n", __func__); 327 return; 328 } 329 330 for (i = 0; i < num_plls; i++) { 331 const struct mtk_pll_data *pll = &plls[i]; 332 333 clk = mtk_clk_register_pll(pll, base); 334 335 if (IS_ERR(clk)) { 336 pr_err("Failed to register clk %s: %ld\n", 337 pll->name, PTR_ERR(clk)); 338 continue; 339 } 340 341 clk_data->clks[pll->id] = clk; 342 } 343 } 344