1 /* 2 * (C) Copyright 2016 Google, Inc 3 * 4 * SPDX-License-Identifier: GPL-2.0 5 */ 6 7 #include <common.h> 8 #include <clk-uclass.h> 9 #include <dm.h> 10 #include <asm/io.h> 11 #include <asm/arch/scu_ast2500.h> 12 #include <dm/lists.h> 13 #include <dt-bindings/clock/ast2500-scu.h> 14 15 /* 16 * MAC Clock Delay settings, taken from Aspeed SDK 17 */ 18 #define RGMII_TXCLK_ODLY 8 19 #define RMII_RXCLK_IDLY 2 20 21 /* 22 * TGMII Clock Duty constants, taken from Aspeed SDK 23 */ 24 #define RGMII2_TXCK_DUTY 0x66 25 #define RGMII1_TXCK_DUTY 0x64 26 27 #define D2PLL_DEFAULT_RATE (250 * 1000 * 1000) 28 29 DECLARE_GLOBAL_DATA_PTR; 30 31 /* 32 * Clock divider/multiplier configuration struct. 33 * For H-PLL and M-PLL the formula is 34 * (Output Frequency) = CLKIN * ((M + 1) / (N + 1)) / (P + 1) 35 * M - Numerator 36 * N - Denumerator 37 * P - Post Divider 38 * They have the same layout in their control register. 39 * 40 * D-PLL and D2-PLL have extra divider (OD + 1), which is not 41 * yet needed and ignored by clock configurations. 42 */ 43 struct ast2500_div_config { 44 unsigned int num; 45 unsigned int denum; 46 unsigned int post_div; 47 }; 48 49 /* 50 * Get the rate of the M-PLL clock from input clock frequency and 51 * the value of the M-PLL Parameter Register. 52 */ 53 static ulong ast2500_get_mpll_rate(ulong clkin, u32 mpll_reg) 54 { 55 const ulong num = (mpll_reg & SCU_MPLL_NUM_MASK) >> SCU_MPLL_NUM_SHIFT; 56 const ulong denum = (mpll_reg & SCU_MPLL_DENUM_MASK) 57 >> SCU_MPLL_DENUM_SHIFT; 58 const ulong post_div = (mpll_reg & SCU_MPLL_POST_MASK) 59 >> SCU_MPLL_POST_SHIFT; 60 61 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1); 62 } 63 64 /* 65 * Get the rate of the H-PLL clock from input clock frequency and 66 * the value of the H-PLL Parameter Register. 67 */ 68 static ulong ast2500_get_hpll_rate(ulong clkin, u32 hpll_reg) 69 { 70 const ulong num = (hpll_reg & SCU_HPLL_NUM_MASK) >> SCU_HPLL_NUM_SHIFT; 71 const ulong denum = (hpll_reg & SCU_HPLL_DENUM_MASK) 72 >> SCU_HPLL_DENUM_SHIFT; 73 const ulong post_div = (hpll_reg & SCU_HPLL_POST_MASK) 74 >> SCU_HPLL_POST_SHIFT; 75 76 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1); 77 } 78 79 static ulong ast2500_get_clkin(struct ast2500_scu *scu) 80 { 81 return readl(&scu->hwstrap) & SCU_HWSTRAP_CLKIN_25MHZ 82 ? 25 * 1000 * 1000 : 24 * 1000 * 1000; 83 } 84 85 /** 86 * Get current rate or uart clock 87 * 88 * @scu SCU registers 89 * @uart_index UART index, 1-5 90 * 91 * @return current setting for uart clock rate 92 */ 93 static ulong ast2500_get_uart_clk_rate(struct ast2500_scu *scu, int uart_index) 94 { 95 /* 96 * ast2500 datasheet is very confusing when it comes to UART clocks, 97 * especially when CLKIN = 25 MHz. The settings are in 98 * different registers and it is unclear how they interact. 99 * 100 * This has only been tested with default settings and CLKIN = 24 MHz. 101 */ 102 ulong uart_clkin; 103 104 if (readl(&scu->misc_ctrl2) & 105 (1 << (uart_index - 1 + SCU_MISC2_UARTCLK_SHIFT))) 106 uart_clkin = 192 * 1000 * 1000; 107 else 108 uart_clkin = 24 * 1000 * 1000; 109 110 if (readl(&scu->misc_ctrl1) & SCU_MISC_UARTCLK_DIV13) 111 uart_clkin /= 13; 112 113 return uart_clkin; 114 } 115 116 static ulong ast2500_clk_get_rate(struct clk *clk) 117 { 118 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev); 119 ulong clkin = ast2500_get_clkin(priv->scu); 120 ulong rate; 121 122 switch (clk->id) { 123 case PLL_HPLL: 124 case ARMCLK: 125 /* 126 * This ignores dynamic/static slowdown of ARMCLK and may 127 * be inaccurate. 128 */ 129 rate = ast2500_get_hpll_rate(clkin, 130 readl(&priv->scu->h_pll_param)); 131 break; 132 case MCLK_DDR: 133 rate = ast2500_get_mpll_rate(clkin, 134 readl(&priv->scu->m_pll_param)); 135 break; 136 case BCLK_PCLK: 137 { 138 ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1) 139 & SCU_PCLK_DIV_MASK) 140 >> SCU_PCLK_DIV_SHIFT); 141 rate = ast2500_get_hpll_rate(clkin, 142 readl(&priv-> 143 scu->h_pll_param)); 144 rate = rate / apb_div; 145 } 146 break; 147 case PCLK_UART1: 148 rate = ast2500_get_uart_clk_rate(priv->scu, 1); 149 break; 150 case PCLK_UART2: 151 rate = ast2500_get_uart_clk_rate(priv->scu, 2); 152 break; 153 case PCLK_UART3: 154 rate = ast2500_get_uart_clk_rate(priv->scu, 3); 155 break; 156 case PCLK_UART4: 157 rate = ast2500_get_uart_clk_rate(priv->scu, 4); 158 break; 159 case PCLK_UART5: 160 rate = ast2500_get_uart_clk_rate(priv->scu, 5); 161 break; 162 default: 163 return -ENOENT; 164 } 165 166 return rate; 167 } 168 169 /* 170 * @input_rate - the rate of input clock in Hz 171 * @requested_rate - desired output rate in Hz 172 * @div - this is an IN/OUT parameter, at input all fields of the config 173 * need to be set to their maximum allowed values. 174 * The result (the best config we could find), would also be returned 175 * in this structure. 176 * 177 * @return The clock rate, when the resulting div_config is used. 178 */ 179 static ulong ast2500_calc_clock_config(ulong input_rate, ulong requested_rate, 180 struct ast2500_div_config *cfg) 181 { 182 /* 183 * The assumption is that kHz precision is good enough and 184 * also enough to avoid overflow when multiplying. 185 */ 186 const ulong input_rate_khz = input_rate / 1000; 187 const ulong rate_khz = requested_rate / 1000; 188 const struct ast2500_div_config max_vals = *cfg; 189 struct ast2500_div_config it = { 0, 0, 0 }; 190 ulong delta = rate_khz; 191 ulong new_rate_khz = 0; 192 193 for (; it.denum <= max_vals.denum; ++it.denum) { 194 for (it.post_div = 0; it.post_div <= max_vals.post_div; 195 ++it.post_div) { 196 it.num = (rate_khz * (it.post_div + 1) / input_rate_khz) 197 * (it.denum + 1); 198 if (it.num > max_vals.num) 199 continue; 200 201 new_rate_khz = (input_rate_khz 202 * ((it.num + 1) / (it.denum + 1))) 203 / (it.post_div + 1); 204 205 /* Keep the rate below requested one. */ 206 if (new_rate_khz > rate_khz) 207 continue; 208 209 if (new_rate_khz - rate_khz < delta) { 210 delta = new_rate_khz - rate_khz; 211 *cfg = it; 212 if (delta == 0) 213 return new_rate_khz * 1000; 214 } 215 } 216 } 217 218 return new_rate_khz * 1000; 219 } 220 221 static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate) 222 { 223 ulong clkin = ast2500_get_clkin(scu); 224 u32 mpll_reg; 225 struct ast2500_div_config div_cfg = { 226 .num = (SCU_MPLL_NUM_MASK >> SCU_MPLL_NUM_SHIFT), 227 .denum = (SCU_MPLL_DENUM_MASK >> SCU_MPLL_DENUM_SHIFT), 228 .post_div = (SCU_MPLL_POST_MASK >> SCU_MPLL_POST_SHIFT), 229 }; 230 231 ast2500_calc_clock_config(clkin, rate, &div_cfg); 232 233 mpll_reg = readl(&scu->m_pll_param); 234 mpll_reg &= ~(SCU_MPLL_POST_MASK | SCU_MPLL_NUM_MASK 235 | SCU_MPLL_DENUM_MASK); 236 mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT) 237 | (div_cfg.num << SCU_MPLL_NUM_SHIFT) 238 | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT); 239 240 ast_scu_unlock(scu); 241 writel(mpll_reg, &scu->m_pll_param); 242 ast_scu_lock(scu); 243 244 return ast2500_get_mpll_rate(clkin, mpll_reg); 245 } 246 247 static ulong ast2500_configure_mac(struct ast2500_scu *scu, int index) 248 { 249 ulong clkin = ast2500_get_clkin(scu); 250 ulong hpll_rate = ast2500_get_hpll_rate(clkin, 251 readl(&scu->h_pll_param)); 252 ulong required_rate; 253 u32 hwstrap; 254 u32 divisor; 255 u32 reset_bit; 256 u32 clkstop_bit; 257 258 /* 259 * According to data sheet, for 10/100 mode the MAC clock frequency 260 * should be at least 25MHz and for 1000 mode at least 100MHz 261 */ 262 hwstrap = readl(&scu->hwstrap); 263 if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII)) 264 required_rate = 100 * 1000 * 1000; 265 else 266 required_rate = 25 * 1000 * 1000; 267 268 divisor = hpll_rate / required_rate; 269 270 if (divisor < 4) { 271 /* Clock can't run fast enough, but let's try anyway */ 272 debug("MAC clock too slow\n"); 273 divisor = 4; 274 } else if (divisor > 16) { 275 /* Can't slow down the clock enough, but let's try anyway */ 276 debug("MAC clock too fast\n"); 277 divisor = 16; 278 } 279 280 switch (index) { 281 case 1: 282 reset_bit = SCU_SYSRESET_MAC1; 283 clkstop_bit = SCU_CLKSTOP_MAC1; 284 break; 285 case 2: 286 reset_bit = SCU_SYSRESET_MAC2; 287 clkstop_bit = SCU_CLKSTOP_MAC2; 288 break; 289 default: 290 return -EINVAL; 291 } 292 293 ast_scu_unlock(scu); 294 clrsetbits_le32(&scu->clk_sel1, SCU_MACCLK_MASK, 295 ((divisor - 2) / 2) << SCU_MACCLK_SHIFT); 296 297 /* 298 * Disable MAC, start its clock and re-enable it. 299 * The procedure and the delays (100us & 10ms) are 300 * specified in the datasheet. 301 */ 302 setbits_le32(&scu->sysreset_ctrl1, reset_bit); 303 udelay(100); 304 clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit); 305 mdelay(10); 306 clrbits_le32(&scu->sysreset_ctrl1, reset_bit); 307 308 writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT) 309 | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT), 310 &scu->clk_duty_sel); 311 312 ast_scu_lock(scu); 313 314 return required_rate; 315 } 316 317 static ulong ast2500_configure_d2pll(struct ast2500_scu *scu, ulong rate) 318 { 319 /* 320 * The values and the meaning of the next three 321 * parameters are undocumented. Taken from Aspeed SDK. 322 */ 323 const u32 d2_pll_ext_param = 0x2c; 324 const u32 d2_pll_sip = 0x11; 325 const u32 d2_pll_sic = 0x18; 326 u32 clk_delay_settings = 327 (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT) 328 | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT) 329 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT) 330 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT); 331 struct ast2500_div_config div_cfg = { 332 .num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT, 333 .denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT, 334 .post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT, 335 }; 336 ulong clkin = ast2500_get_clkin(scu); 337 ulong new_rate; 338 339 ast_scu_unlock(scu); 340 writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT) 341 | SCU_D2PLL_EXT1_OFF 342 | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]); 343 344 /* 345 * Select USB2.0 port1 PHY clock as a clock source for GCRT. 346 * This would disconnect it from D2-PLL. 347 */ 348 clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF, 349 SCU_MISC_GCRT_USB20CLK); 350 351 new_rate = ast2500_calc_clock_config(clkin, rate, &div_cfg); 352 writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT) 353 | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT) 354 | (div_cfg.num << SCU_D2PLL_NUM_SHIFT) 355 | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT) 356 | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT), 357 &scu->d2_pll_param); 358 359 clrbits_le32(&scu->d2_pll_ext_param[0], 360 SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET); 361 362 clrsetbits_le32(&scu->misc_ctrl2, 363 SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL 364 | SCU_MISC2_RGMII_CLKDIV_MASK | 365 SCU_MISC2_RMII_CLKDIV_MASK, 366 (4 << SCU_MISC2_RMII_CLKDIV_SHIFT)); 367 368 writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay); 369 writel(clk_delay_settings, &scu->mac_clk_delay_100M); 370 writel(clk_delay_settings, &scu->mac_clk_delay_10M); 371 372 ast_scu_lock(scu); 373 374 return new_rate; 375 } 376 377 static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate) 378 { 379 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev); 380 381 ulong new_rate; 382 switch (clk->id) { 383 case PLL_MPLL: 384 case MCLK_DDR: 385 new_rate = ast2500_configure_ddr(priv->scu, rate); 386 break; 387 case PLL_D2PLL: 388 new_rate = ast2500_configure_d2pll(priv->scu, rate); 389 break; 390 default: 391 return -ENOENT; 392 } 393 394 return new_rate; 395 } 396 397 static int ast2500_clk_enable(struct clk *clk) 398 { 399 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev); 400 401 switch (clk->id) { 402 /* 403 * For MAC clocks the clock rate is 404 * configured based on whether RGMII or RMII mode has been selected 405 * through hardware strapping. 406 */ 407 case PCLK_MAC1: 408 ast2500_configure_mac(priv->scu, 1); 409 break; 410 case PCLK_MAC2: 411 ast2500_configure_mac(priv->scu, 2); 412 break; 413 case PLL_D2PLL: 414 ast2500_configure_d2pll(priv->scu, D2PLL_DEFAULT_RATE); 415 default: 416 return -ENOENT; 417 } 418 419 return 0; 420 } 421 422 struct clk_ops ast2500_clk_ops = { 423 .get_rate = ast2500_clk_get_rate, 424 .set_rate = ast2500_clk_set_rate, 425 .enable = ast2500_clk_enable, 426 }; 427 428 static int ast2500_clk_probe(struct udevice *dev) 429 { 430 struct ast2500_clk_priv *priv = dev_get_priv(dev); 431 432 priv->scu = dev_get_addr_ptr(dev); 433 if (IS_ERR(priv->scu)) 434 return PTR_ERR(priv->scu); 435 436 return 0; 437 } 438 439 static int ast2500_clk_bind(struct udevice *dev) 440 { 441 int ret; 442 443 /* The reset driver does not have a device node, so bind it here */ 444 ret = device_bind_driver(gd->dm_root, "ast_sysreset", "reset", &dev); 445 if (ret) 446 debug("Warning: No reset driver: ret=%d\n", ret); 447 448 return 0; 449 } 450 451 static const struct udevice_id ast2500_clk_ids[] = { 452 { .compatible = "aspeed,ast2500-scu" }, 453 { } 454 }; 455 456 U_BOOT_DRIVER(aspeed_ast2500_scu) = { 457 .name = "aspeed_ast2500_scu", 458 .id = UCLASS_CLK, 459 .of_match = ast2500_clk_ids, 460 .priv_auto_alloc_size = sizeof(struct ast2500_clk_priv), 461 .ops = &ast2500_clk_ops, 462 .bind = ast2500_clk_bind, 463 .probe = ast2500_clk_probe, 464 }; 465