1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Cortina Gemini SoC Clock Controller driver 4 * Copyright (c) 2017 Linus Walleij <linus.walleij@linaro.org> 5 */ 6 7 #define pr_fmt(fmt) "clk-gemini: " fmt 8 9 #include <linux/init.h> 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/slab.h> 13 #include <linux/err.h> 14 #include <linux/io.h> 15 #include <linux/clk-provider.h> 16 #include <linux/of.h> 17 #include <linux/of_address.h> 18 #include <linux/mfd/syscon.h> 19 #include <linux/regmap.h> 20 #include <linux/spinlock.h> 21 #include <linux/reset-controller.h> 22 #include <dt-bindings/reset/cortina,gemini-reset.h> 23 #include <dt-bindings/clock/cortina,gemini-clock.h> 24 25 /* Globally visible clocks */ 26 static DEFINE_SPINLOCK(gemini_clk_lock); 27 28 #define GEMINI_GLOBAL_STATUS 0x04 29 #define PLL_OSC_SEL BIT(30) 30 #define AHBSPEED_SHIFT (15) 31 #define AHBSPEED_MASK 0x07 32 #define CPU_AHB_RATIO_SHIFT (18) 33 #define CPU_AHB_RATIO_MASK 0x03 34 35 #define GEMINI_GLOBAL_PLL_CONTROL 0x08 36 37 #define GEMINI_GLOBAL_SOFT_RESET 0x0c 38 39 #define GEMINI_GLOBAL_MISC_CONTROL 0x30 40 #define PCI_CLK_66MHZ BIT(18) 41 42 #define GEMINI_GLOBAL_CLOCK_CONTROL 0x34 43 #define PCI_CLKRUN_EN BIT(16) 44 #define TVC_HALFDIV_SHIFT (24) 45 #define TVC_HALFDIV_MASK 0x1f 46 #define SECURITY_CLK_SEL BIT(29) 47 48 #define GEMINI_GLOBAL_PCI_DLL_CONTROL 0x44 49 #define PCI_DLL_BYPASS BIT(31) 50 #define PCI_DLL_TAP_SEL_MASK 0x1f 51 52 /** 53 * struct gemini_data_data - Gemini gated clocks 54 * @bit_idx: the bit used to gate this clock in the clock register 55 * @name: the clock name 56 * @parent_name: the name of the parent clock 57 * @flags: standard clock framework flags 58 */ 59 struct gemini_gate_data { 60 u8 bit_idx; 61 const char *name; 62 const char *parent_name; 63 unsigned long flags; 64 }; 65 66 /** 67 * struct clk_gemini_pci - Gemini PCI clock 68 * @hw: corresponding clock hardware entry 69 * @map: regmap to access the registers 70 * @rate: current rate 71 */ 72 struct clk_gemini_pci { 73 struct clk_hw hw; 74 struct regmap *map; 75 unsigned long rate; 76 }; 77 78 /** 79 * struct gemini_reset - gemini reset controller 80 * @map: regmap to access the containing system controller 81 * @rcdev: reset controller device 82 */ 83 struct gemini_reset { 84 struct regmap *map; 85 struct reset_controller_dev rcdev; 86 }; 87 88 /* Keeps track of all clocks */ 89 static struct clk_hw_onecell_data *gemini_clk_data; 90 91 static const struct gemini_gate_data gemini_gates[] = { 92 { 1, "security-gate", "secdiv", 0 }, 93 { 2, "gmac0-gate", "ahb", 0 }, 94 { 3, "gmac1-gate", "ahb", 0 }, 95 { 4, "sata0-gate", "ahb", 0 }, 96 { 5, "sata1-gate", "ahb", 0 }, 97 { 6, "usb0-gate", "ahb", 0 }, 98 { 7, "usb1-gate", "ahb", 0 }, 99 { 8, "ide-gate", "ahb", 0 }, 100 { 9, "pci-gate", "ahb", 0 }, 101 /* 102 * The DDR controller may never have a driver, but certainly must 103 * not be gated off. 104 */ 105 { 10, "ddr-gate", "ahb", CLK_IS_CRITICAL }, 106 /* 107 * The flash controller must be on to access NOR flash through the 108 * memory map. 109 */ 110 { 11, "flash-gate", "ahb", CLK_IGNORE_UNUSED }, 111 { 12, "tvc-gate", "ahb", 0 }, 112 { 13, "boot-gate", "apb", 0 }, 113 }; 114 115 #define to_pciclk(_hw) container_of(_hw, struct clk_gemini_pci, hw) 116 117 #define to_gemini_reset(p) container_of((p), struct gemini_reset, rcdev) 118 119 static unsigned long gemini_pci_recalc_rate(struct clk_hw *hw, 120 unsigned long parent_rate) 121 { 122 struct clk_gemini_pci *pciclk = to_pciclk(hw); 123 u32 val; 124 125 regmap_read(pciclk->map, GEMINI_GLOBAL_MISC_CONTROL, &val); 126 if (val & PCI_CLK_66MHZ) 127 return 66000000; 128 return 33000000; 129 } 130 131 static long gemini_pci_round_rate(struct clk_hw *hw, unsigned long rate, 132 unsigned long *prate) 133 { 134 /* We support 33 and 66 MHz */ 135 if (rate < 48000000) 136 return 33000000; 137 return 66000000; 138 } 139 140 static int gemini_pci_set_rate(struct clk_hw *hw, unsigned long rate, 141 unsigned long parent_rate) 142 { 143 struct clk_gemini_pci *pciclk = to_pciclk(hw); 144 145 if (rate == 33000000) 146 return regmap_update_bits(pciclk->map, 147 GEMINI_GLOBAL_MISC_CONTROL, 148 PCI_CLK_66MHZ, 0); 149 if (rate == 66000000) 150 return regmap_update_bits(pciclk->map, 151 GEMINI_GLOBAL_MISC_CONTROL, 152 0, PCI_CLK_66MHZ); 153 return -EINVAL; 154 } 155 156 static int gemini_pci_enable(struct clk_hw *hw) 157 { 158 struct clk_gemini_pci *pciclk = to_pciclk(hw); 159 160 regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, 161 0, PCI_CLKRUN_EN); 162 return 0; 163 } 164 165 static void gemini_pci_disable(struct clk_hw *hw) 166 { 167 struct clk_gemini_pci *pciclk = to_pciclk(hw); 168 169 regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, 170 PCI_CLKRUN_EN, 0); 171 } 172 173 static int gemini_pci_is_enabled(struct clk_hw *hw) 174 { 175 struct clk_gemini_pci *pciclk = to_pciclk(hw); 176 unsigned int val; 177 178 regmap_read(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, &val); 179 return !!(val & PCI_CLKRUN_EN); 180 } 181 182 static const struct clk_ops gemini_pci_clk_ops = { 183 .recalc_rate = gemini_pci_recalc_rate, 184 .round_rate = gemini_pci_round_rate, 185 .set_rate = gemini_pci_set_rate, 186 .enable = gemini_pci_enable, 187 .disable = gemini_pci_disable, 188 .is_enabled = gemini_pci_is_enabled, 189 }; 190 191 static struct clk_hw *gemini_pci_clk_setup(const char *name, 192 const char *parent_name, 193 struct regmap *map) 194 { 195 struct clk_gemini_pci *pciclk; 196 struct clk_init_data init; 197 int ret; 198 199 pciclk = kzalloc(sizeof(*pciclk), GFP_KERNEL); 200 if (!pciclk) 201 return ERR_PTR(-ENOMEM); 202 203 init.name = name; 204 init.ops = &gemini_pci_clk_ops; 205 init.flags = 0; 206 init.parent_names = &parent_name; 207 init.num_parents = 1; 208 pciclk->map = map; 209 pciclk->hw.init = &init; 210 211 ret = clk_hw_register(NULL, &pciclk->hw); 212 if (ret) { 213 kfree(pciclk); 214 return ERR_PTR(ret); 215 } 216 217 return &pciclk->hw; 218 } 219 220 /* 221 * This is a self-deasserting reset controller. 222 */ 223 static int gemini_reset(struct reset_controller_dev *rcdev, 224 unsigned long id) 225 { 226 struct gemini_reset *gr = to_gemini_reset(rcdev); 227 228 /* Manual says to always set BIT 30 (CPU1) to 1 */ 229 return regmap_write(gr->map, 230 GEMINI_GLOBAL_SOFT_RESET, 231 BIT(GEMINI_RESET_CPU1) | BIT(id)); 232 } 233 234 static int gemini_reset_assert(struct reset_controller_dev *rcdev, 235 unsigned long id) 236 { 237 return 0; 238 } 239 240 static int gemini_reset_deassert(struct reset_controller_dev *rcdev, 241 unsigned long id) 242 { 243 return 0; 244 } 245 246 static int gemini_reset_status(struct reset_controller_dev *rcdev, 247 unsigned long id) 248 { 249 struct gemini_reset *gr = to_gemini_reset(rcdev); 250 u32 val; 251 int ret; 252 253 ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val); 254 if (ret) 255 return ret; 256 257 return !!(val & BIT(id)); 258 } 259 260 static const struct reset_control_ops gemini_reset_ops = { 261 .reset = gemini_reset, 262 .assert = gemini_reset_assert, 263 .deassert = gemini_reset_deassert, 264 .status = gemini_reset_status, 265 }; 266 267 static int gemini_clk_probe(struct platform_device *pdev) 268 { 269 /* Gives the fracions 1x, 1.5x, 1.85x and 2x */ 270 unsigned int cpu_ahb_mult[4] = { 1, 3, 24, 2 }; 271 unsigned int cpu_ahb_div[4] = { 1, 2, 13, 1 }; 272 void __iomem *base; 273 struct gemini_reset *gr; 274 struct regmap *map; 275 struct clk_hw *hw; 276 struct device *dev = &pdev->dev; 277 struct device_node *np = dev->of_node; 278 unsigned int mult, div; 279 struct resource *res; 280 u32 val; 281 int ret; 282 int i; 283 284 gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL); 285 if (!gr) 286 return -ENOMEM; 287 288 /* Remap the system controller for the exclusive register */ 289 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 290 base = devm_ioremap_resource(dev, res); 291 if (IS_ERR(base)) 292 return PTR_ERR(base); 293 294 map = syscon_node_to_regmap(np); 295 if (IS_ERR(map)) { 296 dev_err(dev, "no syscon regmap\n"); 297 return PTR_ERR(map); 298 } 299 300 gr->map = map; 301 gr->rcdev.owner = THIS_MODULE; 302 gr->rcdev.nr_resets = 32; 303 gr->rcdev.ops = &gemini_reset_ops; 304 gr->rcdev.of_node = np; 305 306 ret = devm_reset_controller_register(dev, &gr->rcdev); 307 if (ret) { 308 dev_err(dev, "could not register reset controller\n"); 309 return ret; 310 } 311 312 /* RTC clock 32768 Hz */ 313 hw = clk_hw_register_fixed_rate(NULL, "rtc", NULL, 0, 32768); 314 gemini_clk_data->hws[GEMINI_CLK_RTC] = hw; 315 316 /* CPU clock derived as a fixed ratio from the AHB clock */ 317 regmap_read(map, GEMINI_GLOBAL_STATUS, &val); 318 val >>= CPU_AHB_RATIO_SHIFT; 319 val &= CPU_AHB_RATIO_MASK; 320 hw = clk_hw_register_fixed_factor(NULL, "cpu", "ahb", 0, 321 cpu_ahb_mult[val], 322 cpu_ahb_div[val]); 323 gemini_clk_data->hws[GEMINI_CLK_CPU] = hw; 324 325 /* Security clock is 1:1 or 0.75 of APB */ 326 regmap_read(map, GEMINI_GLOBAL_CLOCK_CONTROL, &val); 327 if (val & SECURITY_CLK_SEL) { 328 mult = 1; 329 div = 1; 330 } else { 331 mult = 3; 332 div = 4; 333 } 334 hw = clk_hw_register_fixed_factor(NULL, "secdiv", "ahb", 0, mult, div); 335 336 /* 337 * These are the leaf gates, at boot no clocks are gated. 338 */ 339 for (i = 0; i < ARRAY_SIZE(gemini_gates); i++) { 340 const struct gemini_gate_data *gd; 341 342 gd = &gemini_gates[i]; 343 gemini_clk_data->hws[GEMINI_CLK_GATES + i] = 344 clk_hw_register_gate(NULL, gd->name, 345 gd->parent_name, 346 gd->flags, 347 base + GEMINI_GLOBAL_CLOCK_CONTROL, 348 gd->bit_idx, 349 CLK_GATE_SET_TO_DISABLE, 350 &gemini_clk_lock); 351 } 352 353 /* 354 * The TV Interface Controller has a 5-bit half divider register. 355 * This clock is supposed to be 27MHz as this is an exact multiple 356 * of PAL and NTSC frequencies. The register is undocumented :( 357 * FIXME: figure out the parent and how the divider works. 358 */ 359 mult = 1; 360 div = ((val >> TVC_HALFDIV_SHIFT) & TVC_HALFDIV_MASK); 361 dev_dbg(dev, "TVC half divider value = %d\n", div); 362 div += 1; 363 hw = clk_hw_register_fixed_rate(NULL, "tvcdiv", "xtal", 0, 27000000); 364 gemini_clk_data->hws[GEMINI_CLK_TVC] = hw; 365 366 /* FIXME: very unclear what the parent is */ 367 hw = gemini_pci_clk_setup("PCI", "xtal", map); 368 gemini_clk_data->hws[GEMINI_CLK_PCI] = hw; 369 370 /* FIXME: very unclear what the parent is */ 371 hw = clk_hw_register_fixed_rate(NULL, "uart", "xtal", 0, 48000000); 372 gemini_clk_data->hws[GEMINI_CLK_UART] = hw; 373 374 return 0; 375 } 376 377 static const struct of_device_id gemini_clk_dt_ids[] = { 378 { .compatible = "cortina,gemini-syscon", }, 379 { /* sentinel */ }, 380 }; 381 382 static struct platform_driver gemini_clk_driver = { 383 .probe = gemini_clk_probe, 384 .driver = { 385 .name = "gemini-clk", 386 .of_match_table = gemini_clk_dt_ids, 387 .suppress_bind_attrs = true, 388 }, 389 }; 390 builtin_platform_driver(gemini_clk_driver); 391 392 static void __init gemini_cc_init(struct device_node *np) 393 { 394 struct regmap *map; 395 struct clk_hw *hw; 396 unsigned long freq; 397 unsigned int mult, div; 398 u32 val; 399 int ret; 400 int i; 401 402 gemini_clk_data = kzalloc(struct_size(gemini_clk_data, hws, 403 GEMINI_NUM_CLKS), 404 GFP_KERNEL); 405 if (!gemini_clk_data) 406 return; 407 408 /* 409 * This way all clock fetched before the platform device probes, 410 * except those we assign here for early use, will be deferred. 411 */ 412 for (i = 0; i < GEMINI_NUM_CLKS; i++) 413 gemini_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER); 414 415 map = syscon_node_to_regmap(np); 416 if (IS_ERR(map)) { 417 pr_err("no syscon regmap\n"); 418 return; 419 } 420 /* 421 * We check that the regmap works on this very first access, 422 * but as this is an MMIO-backed regmap, subsequent regmap 423 * access is not going to fail and we skip error checks from 424 * this point. 425 */ 426 ret = regmap_read(map, GEMINI_GLOBAL_STATUS, &val); 427 if (ret) { 428 pr_err("failed to read global status register\n"); 429 return; 430 } 431 432 /* 433 * XTAL is the crystal oscillator, 60 or 30 MHz selected from 434 * strap pin E6 435 */ 436 if (val & PLL_OSC_SEL) 437 freq = 30000000; 438 else 439 freq = 60000000; 440 hw = clk_hw_register_fixed_rate(NULL, "xtal", NULL, 0, freq); 441 pr_debug("main crystal @%lu MHz\n", freq / 1000000); 442 443 /* VCO clock derived from the crystal */ 444 mult = 13 + ((val >> AHBSPEED_SHIFT) & AHBSPEED_MASK); 445 div = 2; 446 /* If we run on 30 MHz crystal we have to multiply with two */ 447 if (val & PLL_OSC_SEL) 448 mult *= 2; 449 hw = clk_hw_register_fixed_factor(NULL, "vco", "xtal", 0, mult, div); 450 451 /* The AHB clock is always 1/3 of the VCO */ 452 hw = clk_hw_register_fixed_factor(NULL, "ahb", "vco", 0, 1, 3); 453 gemini_clk_data->hws[GEMINI_CLK_AHB] = hw; 454 455 /* The APB clock is always 1/6 of the AHB */ 456 hw = clk_hw_register_fixed_factor(NULL, "apb", "ahb", 0, 1, 6); 457 gemini_clk_data->hws[GEMINI_CLK_APB] = hw; 458 459 /* Register the clocks to be accessed by the device tree */ 460 gemini_clk_data->num = GEMINI_NUM_CLKS; 461 of_clk_add_hw_provider(np, of_clk_hw_onecell_get, gemini_clk_data); 462 } 463 CLK_OF_DECLARE_DRIVER(gemini_cc, "cortina,gemini-syscon", gemini_cc_init); 464