1 /* 2 * [origin: Linux kernel linux/arch/arm/mach-at91/clock.c] 3 * 4 * Copyright (C) 2005 David Brownell 5 * Copyright (C) 2005 Ivan Kokshaysky 6 * Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> 7 * 8 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 #include <common.h> 12 #include <asm/io.h> 13 #include <asm/arch/hardware.h> 14 #include <asm/arch/at91_pmc.h> 15 #include <asm/arch/clk.h> 16 17 #if !defined(CONFIG_AT91FAMILY) 18 # error You need to define CONFIG_AT91FAMILY in your board config! 19 #endif 20 21 #define EN_PLLB_TIMEOUT 500 22 23 DECLARE_GLOBAL_DATA_PTR; 24 25 static unsigned long at91_css_to_rate(unsigned long css) 26 { 27 switch (css) { 28 case AT91_PMC_MCKR_CSS_SLOW: 29 return CONFIG_SYS_AT91_SLOW_CLOCK; 30 case AT91_PMC_MCKR_CSS_MAIN: 31 return gd->arch.main_clk_rate_hz; 32 case AT91_PMC_MCKR_CSS_PLLA: 33 return gd->arch.plla_rate_hz; 34 case AT91_PMC_MCKR_CSS_PLLB: 35 return gd->arch.pllb_rate_hz; 36 } 37 38 return 0; 39 } 40 41 #ifdef CONFIG_USB_ATMEL 42 static unsigned at91_pll_calc(unsigned main_freq, unsigned out_freq) 43 { 44 unsigned i, div = 0, mul = 0, diff = 1 << 30; 45 unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00; 46 47 /* PLL output max 240 MHz (or 180 MHz per errata) */ 48 if (out_freq > 240000000) 49 goto fail; 50 51 for (i = 1; i < 256; i++) { 52 int diff1; 53 unsigned input, mul1; 54 55 /* 56 * PLL input between 1MHz and 32MHz per spec, but lower 57 * frequences seem necessary in some cases so allow 100K. 58 * Warning: some newer products need 2MHz min. 59 */ 60 input = main_freq / i; 61 #if defined(CONFIG_AT91SAM9G20) 62 if (input < 2000000) 63 continue; 64 #endif 65 if (input < 100000) 66 continue; 67 if (input > 32000000) 68 continue; 69 70 mul1 = out_freq / input; 71 #if defined(CONFIG_AT91SAM9G20) 72 if (mul > 63) 73 continue; 74 #endif 75 if (mul1 > 2048) 76 continue; 77 if (mul1 < 2) 78 goto fail; 79 80 diff1 = out_freq - input * mul1; 81 if (diff1 < 0) 82 diff1 = -diff1; 83 if (diff > diff1) { 84 diff = diff1; 85 div = i; 86 mul = mul1; 87 if (diff == 0) 88 break; 89 } 90 } 91 if (i == 256 && diff > (out_freq >> 5)) 92 goto fail; 93 return ret | ((mul - 1) << 16) | div; 94 fail: 95 return 0; 96 } 97 #endif 98 99 static u32 at91_pll_rate(u32 freq, u32 reg) 100 { 101 unsigned mul, div; 102 103 div = reg & 0xff; 104 mul = (reg >> 16) & 0x7ff; 105 if (div && mul) { 106 freq /= div; 107 freq *= mul + 1; 108 } else 109 freq = 0; 110 111 return freq; 112 } 113 114 int at91_clock_init(unsigned long main_clock) 115 { 116 unsigned freq, mckr; 117 at91_pmc_t *pmc = (at91_pmc_t *) ATMEL_BASE_PMC; 118 #ifndef CONFIG_SYS_AT91_MAIN_CLOCK 119 unsigned tmp; 120 /* 121 * When the bootloader initialized the main oscillator correctly, 122 * there's no problem using the cycle counter. But if it didn't, 123 * or when using oscillator bypass mode, we must be told the speed 124 * of the main clock. 125 */ 126 if (!main_clock) { 127 do { 128 tmp = readl(&pmc->mcfr); 129 } while (!(tmp & AT91_PMC_MCFR_MAINRDY)); 130 tmp &= AT91_PMC_MCFR_MAINF_MASK; 131 main_clock = tmp * (CONFIG_SYS_AT91_SLOW_CLOCK / 16); 132 } 133 #endif 134 gd->arch.main_clk_rate_hz = main_clock; 135 136 /* report if PLLA is more than mildly overclocked */ 137 gd->arch.plla_rate_hz = at91_pll_rate(main_clock, readl(&pmc->pllar)); 138 139 #ifdef CONFIG_USB_ATMEL 140 /* 141 * USB clock init: choose 48 MHz PLLB value, 142 * disable 48MHz clock during usb peripheral suspend. 143 * 144 * REVISIT: assumes MCK doesn't derive from PLLB! 145 */ 146 gd->arch.at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | 147 AT91_PMC_PLLBR_USBDIV_2; 148 gd->arch.pllb_rate_hz = at91_pll_rate(main_clock, 149 gd->arch.at91_pllb_usb_init); 150 #endif 151 152 /* 153 * MCK and CPU derive from one of those primary clocks. 154 * For now, assume this parentage won't change. 155 */ 156 mckr = readl(&pmc->mckr); 157 #if defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45) \ 158 || defined(CONFIG_AT91SAM9N12) || defined(CONFIG_AT91SAM9X5) 159 /* plla divisor by 2 */ 160 gd->arch.plla_rate_hz /= (1 << ((mckr & 1 << 12) >> 12)); 161 #endif 162 gd->arch.mck_rate_hz = at91_css_to_rate(mckr & AT91_PMC_MCKR_CSS_MASK); 163 freq = gd->arch.mck_rate_hz; 164 165 #if defined(CONFIG_AT91SAM9X5) 166 /* different in prescale on at91sam9x5 */ 167 freq /= (1 << ((mckr & AT91_PMC_MCKR_PRES_MASK) >> 4)); 168 #else 169 freq /= (1 << ((mckr & AT91_PMC_MCKR_PRES_MASK) >> 2)); /* prescale */ 170 #endif 171 172 #if defined(CONFIG_AT91SAM9G20) 173 /* mdiv ; (x >> 7) = ((x >> 8) * 2) */ 174 gd->arch.mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ? 175 freq / ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 7) : freq; 176 if (mckr & AT91_PMC_MCKR_MDIV_MASK) 177 freq /= 2; /* processor clock division */ 178 #elif defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45) \ 179 || defined(CONFIG_AT91SAM9N12) || defined(CONFIG_AT91SAM9X5) 180 /* mdiv <==> divisor 181 * 0 <==> 1 182 * 1 <==> 2 183 * 2 <==> 4 184 * 3 <==> 3 185 */ 186 gd->arch.mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) == 187 (AT91_PMC_MCKR_MDIV_2 | AT91_PMC_MCKR_MDIV_4) 188 ? freq / 3 189 : freq / (1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8)); 190 #else 191 gd->arch.mck_rate_hz = freq / 192 (1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8)); 193 #endif 194 gd->arch.cpu_clk_rate_hz = freq; 195 196 return 0; 197 } 198 199 #if !defined(AT91_PLL_LOCK_TIMEOUT) 200 #define AT91_PLL_LOCK_TIMEOUT 1000000 201 #endif 202 203 void at91_plla_init(u32 pllar) 204 { 205 struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; 206 207 writel(pllar, &pmc->pllar); 208 while (!(readl(&pmc->sr) & AT91_PMC_LOCKA)) 209 ; 210 } 211 void at91_pllb_init(u32 pllbr) 212 { 213 struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; 214 215 writel(pllbr, &pmc->pllbr); 216 while (!(readl(&pmc->sr) & AT91_PMC_LOCKB)) 217 ; 218 } 219 220 void at91_mck_init(u32 mckr) 221 { 222 struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; 223 u32 tmp; 224 225 tmp = readl(&pmc->mckr); 226 tmp &= ~AT91_PMC_MCKR_PRES_MASK; 227 tmp |= mckr & AT91_PMC_MCKR_PRES_MASK; 228 writel(tmp, &pmc->mckr); 229 while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY)) 230 ; 231 232 tmp = readl(&pmc->mckr); 233 tmp &= ~AT91_PMC_MCKR_MDIV_MASK; 234 tmp |= mckr & AT91_PMC_MCKR_MDIV_MASK; 235 writel(tmp, &pmc->mckr); 236 while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY)) 237 ; 238 239 tmp = readl(&pmc->mckr); 240 tmp &= ~AT91_PMC_MCKR_PLLADIV_MASK; 241 tmp |= mckr & AT91_PMC_MCKR_PLLADIV_MASK; 242 writel(tmp, &pmc->mckr); 243 while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY)) 244 ; 245 246 tmp = readl(&pmc->mckr); 247 tmp &= ~AT91_PMC_MCKR_CSS_MASK; 248 tmp |= mckr & AT91_PMC_MCKR_CSS_MASK; 249 writel(tmp, &pmc->mckr); 250 while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY)) 251 ; 252 } 253 254 int at91_pllb_clk_enable(u32 pllbr) 255 { 256 struct at91_pmc *pmc = (at91_pmc_t *)ATMEL_BASE_PMC; 257 ulong start_time, tmp_time; 258 259 start_time = get_timer(0); 260 writel(pllbr, &pmc->pllbr); 261 while ((readl(&pmc->sr) & AT91_PMC_LOCKB) != AT91_PMC_LOCKB) { 262 tmp_time = get_timer(0); 263 if ((tmp_time - start_time) > EN_PLLB_TIMEOUT) { 264 printf("ERROR: failed to enable PLLB\n"); 265 return -1; 266 } 267 } 268 269 return 0; 270 } 271 272 int at91_pllb_clk_disable(void) 273 { 274 struct at91_pmc *pmc = (at91_pmc_t *)ATMEL_BASE_PMC; 275 ulong start_time, tmp_time; 276 277 start_time = get_timer(0); 278 writel(0, &pmc->pllbr); 279 while ((readl(&pmc->sr) & AT91_PMC_LOCKB) != 0) { 280 tmp_time = get_timer(0); 281 if ((tmp_time - start_time) > EN_PLLB_TIMEOUT) { 282 printf("ERROR: failed to disable PLLB\n"); 283 return -1; 284 } 285 } 286 287 return 0; 288 } 289