1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Faraday Technology FTTMR010 timer driver 4 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> 5 * 6 * Based on a rewrite of arch/arm/mach-gemini/timer.c: 7 * Copyright (C) 2001-2006 Storlink, Corp. 8 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt> 9 */ 10 #include <linux/interrupt.h> 11 #include <linux/io.h> 12 #include <linux/of.h> 13 #include <linux/of_address.h> 14 #include <linux/of_irq.h> 15 #include <linux/clockchips.h> 16 #include <linux/clocksource.h> 17 #include <linux/sched_clock.h> 18 #include <linux/clk.h> 19 #include <linux/slab.h> 20 #include <linux/bitops.h> 21 #include <linux/delay.h> 22 23 /* 24 * Register definitions common for all the timer variants. 25 */ 26 #define TIMER1_COUNT (0x00) 27 #define TIMER1_LOAD (0x04) 28 #define TIMER1_MATCH1 (0x08) 29 #define TIMER1_MATCH2 (0x0c) 30 #define TIMER2_COUNT (0x10) 31 #define TIMER2_LOAD (0x14) 32 #define TIMER2_MATCH1 (0x18) 33 #define TIMER2_MATCH2 (0x1c) 34 #define TIMER3_COUNT (0x20) 35 #define TIMER3_LOAD (0x24) 36 #define TIMER3_MATCH1 (0x28) 37 #define TIMER3_MATCH2 (0x2c) 38 #define TIMER_CR (0x30) 39 40 /* 41 * Control register set to clear for ast2600 only. 42 */ 43 #define AST2600_TIMER_CR_CLR (0x3c) 44 45 /* 46 * Control register (TMC30) bit fields for fttmr010/gemini/moxart timers. 47 */ 48 #define TIMER_1_CR_ENABLE BIT(0) 49 #define TIMER_1_CR_CLOCK BIT(1) 50 #define TIMER_1_CR_INT BIT(2) 51 #define TIMER_2_CR_ENABLE BIT(3) 52 #define TIMER_2_CR_CLOCK BIT(4) 53 #define TIMER_2_CR_INT BIT(5) 54 #define TIMER_3_CR_ENABLE BIT(6) 55 #define TIMER_3_CR_CLOCK BIT(7) 56 #define TIMER_3_CR_INT BIT(8) 57 #define TIMER_1_CR_UPDOWN BIT(9) 58 #define TIMER_2_CR_UPDOWN BIT(10) 59 #define TIMER_3_CR_UPDOWN BIT(11) 60 61 /* 62 * Control register (TMC30) bit fields for aspeed ast2400/ast2500 timers. 63 * The aspeed timers move bits around in the control register and lacks 64 * bits for setting the timer to count upwards. 65 */ 66 #define TIMER_1_CR_ASPEED_ENABLE BIT(0) 67 #define TIMER_1_CR_ASPEED_CLOCK BIT(1) 68 #define TIMER_1_CR_ASPEED_INT BIT(2) 69 #define TIMER_2_CR_ASPEED_ENABLE BIT(4) 70 #define TIMER_2_CR_ASPEED_CLOCK BIT(5) 71 #define TIMER_2_CR_ASPEED_INT BIT(6) 72 #define TIMER_3_CR_ASPEED_ENABLE BIT(8) 73 #define TIMER_3_CR_ASPEED_CLOCK BIT(9) 74 #define TIMER_3_CR_ASPEED_INT BIT(10) 75 76 /* 77 * Interrupt status/mask register definitions for fttmr010/gemini/moxart 78 * timers. 79 * The registers don't exist and they are not needed on aspeed timers 80 * because: 81 * - aspeed timer overflow interrupt is controlled by bits in Control 82 * Register (TMC30). 83 * - aspeed timers always generate interrupt when either one of the 84 * Match registers equals to Status register. 85 */ 86 #define TIMER_INTR_STATE (0x34) 87 #define TIMER_INTR_MASK (0x38) 88 #define TIMER_1_INT_MATCH1 BIT(0) 89 #define TIMER_1_INT_MATCH2 BIT(1) 90 #define TIMER_1_INT_OVERFLOW BIT(2) 91 #define TIMER_2_INT_MATCH1 BIT(3) 92 #define TIMER_2_INT_MATCH2 BIT(4) 93 #define TIMER_2_INT_OVERFLOW BIT(5) 94 #define TIMER_3_INT_MATCH1 BIT(6) 95 #define TIMER_3_INT_MATCH2 BIT(7) 96 #define TIMER_3_INT_OVERFLOW BIT(8) 97 #define TIMER_INT_ALL_MASK 0x1ff 98 99 struct fttmr010 { 100 void __iomem *base; 101 unsigned int tick_rate; 102 bool is_aspeed; 103 u32 t1_enable_val; 104 struct clock_event_device clkevt; 105 int (*timer_shutdown)(struct clock_event_device *evt); 106 #ifdef CONFIG_ARM 107 struct delay_timer delay_timer; 108 #endif 109 }; 110 111 /* 112 * A local singleton used by sched_clock and delay timer reads, which are 113 * fast and stateless 114 */ 115 static struct fttmr010 *local_fttmr; 116 117 static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt) 118 { 119 return container_of(evt, struct fttmr010, clkevt); 120 } 121 122 static unsigned long fttmr010_read_current_timer_up(void) 123 { 124 return readl(local_fttmr->base + TIMER2_COUNT); 125 } 126 127 static unsigned long fttmr010_read_current_timer_down(void) 128 { 129 return ~readl(local_fttmr->base + TIMER2_COUNT); 130 } 131 132 static u64 notrace fttmr010_read_sched_clock_up(void) 133 { 134 return fttmr010_read_current_timer_up(); 135 } 136 137 static u64 notrace fttmr010_read_sched_clock_down(void) 138 { 139 return fttmr010_read_current_timer_down(); 140 } 141 142 static int fttmr010_timer_set_next_event(unsigned long cycles, 143 struct clock_event_device *evt) 144 { 145 struct fttmr010 *fttmr010 = to_fttmr010(evt); 146 u32 cr; 147 148 /* Stop */ 149 fttmr010->timer_shutdown(evt); 150 151 if (fttmr010->is_aspeed) { 152 /* 153 * ASPEED Timer Controller will load TIMER1_LOAD register 154 * into TIMER1_COUNT register when the timer is re-enabled. 155 */ 156 writel(cycles, fttmr010->base + TIMER1_LOAD); 157 } else { 158 /* Setup the match register forward in time */ 159 cr = readl(fttmr010->base + TIMER1_COUNT); 160 writel(cr + cycles, fttmr010->base + TIMER1_MATCH1); 161 } 162 163 /* Start */ 164 cr = readl(fttmr010->base + TIMER_CR); 165 cr |= fttmr010->t1_enable_val; 166 writel(cr, fttmr010->base + TIMER_CR); 167 168 return 0; 169 } 170 171 static int ast2600_timer_shutdown(struct clock_event_device *evt) 172 { 173 struct fttmr010 *fttmr010 = to_fttmr010(evt); 174 175 /* Stop */ 176 writel(fttmr010->t1_enable_val, fttmr010->base + AST2600_TIMER_CR_CLR); 177 178 return 0; 179 } 180 181 static int fttmr010_timer_shutdown(struct clock_event_device *evt) 182 { 183 struct fttmr010 *fttmr010 = to_fttmr010(evt); 184 u32 cr; 185 186 /* Stop */ 187 cr = readl(fttmr010->base + TIMER_CR); 188 cr &= ~fttmr010->t1_enable_val; 189 writel(cr, fttmr010->base + TIMER_CR); 190 191 return 0; 192 } 193 194 static int fttmr010_timer_set_oneshot(struct clock_event_device *evt) 195 { 196 struct fttmr010 *fttmr010 = to_fttmr010(evt); 197 u32 cr; 198 199 /* Stop */ 200 fttmr010->timer_shutdown(evt); 201 202 /* Setup counter start from 0 or ~0 */ 203 writel(0, fttmr010->base + TIMER1_COUNT); 204 if (fttmr010->is_aspeed) { 205 writel(~0, fttmr010->base + TIMER1_LOAD); 206 } else { 207 writel(0, fttmr010->base + TIMER1_LOAD); 208 209 /* Enable interrupt */ 210 cr = readl(fttmr010->base + TIMER_INTR_MASK); 211 cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); 212 cr |= TIMER_1_INT_MATCH1; 213 writel(cr, fttmr010->base + TIMER_INTR_MASK); 214 } 215 216 return 0; 217 } 218 219 static int fttmr010_timer_set_periodic(struct clock_event_device *evt) 220 { 221 struct fttmr010 *fttmr010 = to_fttmr010(evt); 222 u32 period = DIV_ROUND_CLOSEST(fttmr010->tick_rate, HZ); 223 u32 cr; 224 225 /* Stop */ 226 fttmr010->timer_shutdown(evt); 227 228 /* Setup timer to fire at 1/HZ intervals. */ 229 if (fttmr010->is_aspeed) { 230 writel(period, fttmr010->base + TIMER1_LOAD); 231 } else { 232 cr = 0xffffffff - (period - 1); 233 writel(cr, fttmr010->base + TIMER1_COUNT); 234 writel(cr, fttmr010->base + TIMER1_LOAD); 235 236 /* Enable interrupt on overflow */ 237 cr = readl(fttmr010->base + TIMER_INTR_MASK); 238 cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2); 239 cr |= TIMER_1_INT_OVERFLOW; 240 writel(cr, fttmr010->base + TIMER_INTR_MASK); 241 } 242 243 /* Start the timer */ 244 cr = readl(fttmr010->base + TIMER_CR); 245 cr |= fttmr010->t1_enable_val; 246 writel(cr, fttmr010->base + TIMER_CR); 247 248 return 0; 249 } 250 251 /* 252 * IRQ handler for the timer 253 */ 254 static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id) 255 { 256 struct clock_event_device *evt = dev_id; 257 258 evt->event_handler(evt); 259 return IRQ_HANDLED; 260 } 261 262 static irqreturn_t ast2600_timer_interrupt(int irq, void *dev_id) 263 { 264 struct clock_event_device *evt = dev_id; 265 struct fttmr010 *fttmr010 = to_fttmr010(evt); 266 267 writel(0x1, fttmr010->base + TIMER_INTR_STATE); 268 269 evt->event_handler(evt); 270 return IRQ_HANDLED; 271 } 272 273 static int __init fttmr010_common_init(struct device_node *np, 274 bool is_aspeed, bool is_ast2600) 275 { 276 struct fttmr010 *fttmr010; 277 int irq; 278 struct clk *clk; 279 int ret; 280 u32 val; 281 282 /* 283 * These implementations require a clock reference. 284 * FIXME: we currently only support clocking using PCLK 285 * and using EXTCLK is not supported in the driver. 286 */ 287 clk = of_clk_get_by_name(np, "PCLK"); 288 if (IS_ERR(clk)) { 289 pr_err("could not get PCLK\n"); 290 return PTR_ERR(clk); 291 } 292 ret = clk_prepare_enable(clk); 293 if (ret) { 294 pr_err("failed to enable PCLK\n"); 295 clk_put(clk); 296 return ret; 297 } 298 299 fttmr010 = kzalloc_obj(*fttmr010); 300 if (!fttmr010) { 301 ret = -ENOMEM; 302 goto out_disable_clock; 303 } 304 fttmr010->tick_rate = clk_get_rate(clk); 305 306 fttmr010->base = of_iomap(np, 0); 307 if (!fttmr010->base) { 308 pr_err("Can't remap registers\n"); 309 ret = -ENXIO; 310 goto out_free; 311 } 312 /* IRQ for timer 1 */ 313 irq = irq_of_parse_and_map(np, 0); 314 if (irq <= 0) { 315 pr_err("Can't parse IRQ\n"); 316 ret = -EINVAL; 317 goto out_unmap; 318 } 319 320 /* 321 * The Aspeed timers move bits around in the control register. 322 */ 323 if (is_aspeed) { 324 fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE | 325 TIMER_1_CR_ASPEED_INT; 326 fttmr010->is_aspeed = true; 327 } else { 328 fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT; 329 330 /* 331 * Reset the interrupt mask and status 332 */ 333 writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK); 334 writel(0, fttmr010->base + TIMER_INTR_STATE); 335 } 336 337 /* 338 * Enable timer 1 count up, timer 2 count up, except on Aspeed, 339 * where everything just counts down. 340 */ 341 if (is_aspeed) 342 val = TIMER_2_CR_ASPEED_ENABLE; 343 else { 344 val = TIMER_2_CR_ENABLE | TIMER_1_CR_UPDOWN | 345 TIMER_2_CR_UPDOWN; 346 } 347 writel(val, fttmr010->base + TIMER_CR); 348 349 /* 350 * Setup free-running clocksource timer (interrupts 351 * disabled.) 352 */ 353 local_fttmr = fttmr010; 354 writel(0, fttmr010->base + TIMER2_COUNT); 355 writel(0, fttmr010->base + TIMER2_MATCH1); 356 writel(0, fttmr010->base + TIMER2_MATCH2); 357 358 if (fttmr010->is_aspeed) { 359 writel(~0, fttmr010->base + TIMER2_LOAD); 360 clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, 361 "FTTMR010-TIMER2", 362 fttmr010->tick_rate, 363 300, 32, clocksource_mmio_readl_down); 364 sched_clock_register(fttmr010_read_sched_clock_down, 32, 365 fttmr010->tick_rate); 366 } else { 367 writel(0, fttmr010->base + TIMER2_LOAD); 368 clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, 369 "FTTMR010-TIMER2", 370 fttmr010->tick_rate, 371 300, 32, clocksource_mmio_readl_up); 372 sched_clock_register(fttmr010_read_sched_clock_up, 32, 373 fttmr010->tick_rate); 374 } 375 376 /* 377 * Setup clockevent timer (interrupt-driven) on timer 1. 378 */ 379 writel(0, fttmr010->base + TIMER1_COUNT); 380 writel(0, fttmr010->base + TIMER1_LOAD); 381 writel(0, fttmr010->base + TIMER1_MATCH1); 382 writel(0, fttmr010->base + TIMER1_MATCH2); 383 384 if (is_ast2600) { 385 fttmr010->timer_shutdown = ast2600_timer_shutdown; 386 ret = request_irq(irq, ast2600_timer_interrupt, 387 IRQF_TIMER, "FTTMR010-TIMER1", 388 &fttmr010->clkevt); 389 } else { 390 fttmr010->timer_shutdown = fttmr010_timer_shutdown; 391 ret = request_irq(irq, fttmr010_timer_interrupt, 392 IRQF_TIMER, "FTTMR010-TIMER1", 393 &fttmr010->clkevt); 394 } 395 if (ret) { 396 pr_err("FTTMR010-TIMER1 no IRQ\n"); 397 goto out_unmap; 398 } 399 400 fttmr010->clkevt.name = "FTTMR010-TIMER1"; 401 /* Reasonably fast and accurate clock event */ 402 fttmr010->clkevt.rating = 300; 403 fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | 404 CLOCK_EVT_FEAT_ONESHOT; 405 fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event; 406 fttmr010->clkevt.set_state_shutdown = fttmr010->timer_shutdown; 407 fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic; 408 fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot; 409 fttmr010->clkevt.tick_resume = fttmr010->timer_shutdown; 410 fttmr010->clkevt.cpumask = cpumask_of(0); 411 fttmr010->clkevt.irq = irq; 412 clockevents_config_and_register(&fttmr010->clkevt, 413 fttmr010->tick_rate, 414 1, 0xffffffff); 415 416 #ifdef CONFIG_ARM 417 /* Also use this timer for delays */ 418 if (fttmr010->is_aspeed) 419 fttmr010->delay_timer.read_current_timer = 420 fttmr010_read_current_timer_down; 421 else 422 fttmr010->delay_timer.read_current_timer = 423 fttmr010_read_current_timer_up; 424 fttmr010->delay_timer.freq = fttmr010->tick_rate; 425 register_current_timer_delay(&fttmr010->delay_timer); 426 #endif 427 428 return 0; 429 430 out_unmap: 431 iounmap(fttmr010->base); 432 out_free: 433 kfree(fttmr010); 434 out_disable_clock: 435 clk_disable_unprepare(clk); 436 clk_put(clk); 437 438 return ret; 439 } 440 441 static __init int ast2600_timer_init(struct device_node *np) 442 { 443 return fttmr010_common_init(np, true, true); 444 } 445 446 static __init int aspeed_timer_init(struct device_node *np) 447 { 448 return fttmr010_common_init(np, true, false); 449 } 450 451 static __init int fttmr010_timer_init(struct device_node *np) 452 { 453 return fttmr010_common_init(np, false, false); 454 } 455 456 TIMER_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init); 457 TIMER_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init); 458 TIMER_OF_DECLARE(moxart, "moxa,moxart-timer", fttmr010_timer_init); 459 TIMER_OF_DECLARE(ast2400, "aspeed,ast2400-timer", aspeed_timer_init); 460 TIMER_OF_DECLARE(ast2500, "aspeed,ast2500-timer", aspeed_timer_init); 461 TIMER_OF_DECLARE(ast2600, "aspeed,ast2600-timer", ast2600_timer_init); 462