1 /* 2 * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2012-2013 Xilinx, Inc. 4 * Copyright (C) 2007-2009 PetaLogix 5 * Copyright (C) 2006 Atmark Techno, Inc. 6 * 7 * This file is subject to the terms and conditions of the GNU General Public 8 * License. See the file "COPYING" in the main directory of this archive 9 * for more details. 10 */ 11 12 #include <linux/interrupt.h> 13 #include <linux/delay.h> 14 #include <linux/sched.h> 15 #include <linux/sched_clock.h> 16 #include <linux/clk.h> 17 #include <linux/clockchips.h> 18 #include <linux/of_address.h> 19 #include <linux/of_irq.h> 20 #include <linux/timecounter.h> 21 #include <asm/cpuinfo.h> 22 23 static void __iomem *timer_baseaddr; 24 25 static unsigned int freq_div_hz; 26 static unsigned int timer_clock_freq; 27 28 #define TCSR0 (0x00) 29 #define TLR0 (0x04) 30 #define TCR0 (0x08) 31 #define TCSR1 (0x10) 32 #define TLR1 (0x14) 33 #define TCR1 (0x18) 34 35 #define TCSR_MDT (1<<0) 36 #define TCSR_UDT (1<<1) 37 #define TCSR_GENT (1<<2) 38 #define TCSR_CAPT (1<<3) 39 #define TCSR_ARHT (1<<4) 40 #define TCSR_LOAD (1<<5) 41 #define TCSR_ENIT (1<<6) 42 #define TCSR_ENT (1<<7) 43 #define TCSR_TINT (1<<8) 44 #define TCSR_PWMA (1<<9) 45 #define TCSR_ENALL (1<<10) 46 47 static unsigned int (*read_fn)(void __iomem *); 48 static void (*write_fn)(u32, void __iomem *); 49 50 static void timer_write32(u32 val, void __iomem *addr) 51 { 52 iowrite32(val, addr); 53 } 54 55 static unsigned int timer_read32(void __iomem *addr) 56 { 57 return ioread32(addr); 58 } 59 60 static void timer_write32_be(u32 val, void __iomem *addr) 61 { 62 iowrite32be(val, addr); 63 } 64 65 static unsigned int timer_read32_be(void __iomem *addr) 66 { 67 return ioread32be(addr); 68 } 69 70 static inline void xilinx_timer0_stop(void) 71 { 72 write_fn(read_fn(timer_baseaddr + TCSR0) & ~TCSR_ENT, 73 timer_baseaddr + TCSR0); 74 } 75 76 static inline void xilinx_timer0_start_periodic(unsigned long load_val) 77 { 78 if (!load_val) 79 load_val = 1; 80 /* loading value to timer reg */ 81 write_fn(load_val, timer_baseaddr + TLR0); 82 83 /* load the initial value */ 84 write_fn(TCSR_LOAD, timer_baseaddr + TCSR0); 85 86 /* see timer data sheet for detail 87 * !ENALL - don't enable 'em all 88 * !PWMA - disable pwm 89 * TINT - clear interrupt status 90 * ENT- enable timer itself 91 * ENIT - enable interrupt 92 * !LOAD - clear the bit to let go 93 * ARHT - auto reload 94 * !CAPT - no external trigger 95 * !GENT - no external signal 96 * UDT - set the timer as down counter 97 * !MDT0 - generate mode 98 */ 99 write_fn(TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT, 100 timer_baseaddr + TCSR0); 101 } 102 103 static inline void xilinx_timer0_start_oneshot(unsigned long load_val) 104 { 105 if (!load_val) 106 load_val = 1; 107 /* loading value to timer reg */ 108 write_fn(load_val, timer_baseaddr + TLR0); 109 110 /* load the initial value */ 111 write_fn(TCSR_LOAD, timer_baseaddr + TCSR0); 112 113 write_fn(TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT, 114 timer_baseaddr + TCSR0); 115 } 116 117 static int xilinx_timer_set_next_event(unsigned long delta, 118 struct clock_event_device *dev) 119 { 120 pr_debug("%s: next event, delta %x\n", __func__, (u32)delta); 121 xilinx_timer0_start_oneshot(delta); 122 return 0; 123 } 124 125 static int xilinx_timer_shutdown(struct clock_event_device *evt) 126 { 127 pr_info("%s\n", __func__); 128 xilinx_timer0_stop(); 129 return 0; 130 } 131 132 static int xilinx_timer_set_periodic(struct clock_event_device *evt) 133 { 134 pr_info("%s\n", __func__); 135 xilinx_timer0_start_periodic(freq_div_hz); 136 return 0; 137 } 138 139 static struct clock_event_device clockevent_xilinx_timer = { 140 .name = "xilinx_clockevent", 141 .features = CLOCK_EVT_FEAT_ONESHOT | 142 CLOCK_EVT_FEAT_PERIODIC, 143 .shift = 8, 144 .rating = 300, 145 .set_next_event = xilinx_timer_set_next_event, 146 .set_state_shutdown = xilinx_timer_shutdown, 147 .set_state_periodic = xilinx_timer_set_periodic, 148 }; 149 150 static inline void timer_ack(void) 151 { 152 write_fn(read_fn(timer_baseaddr + TCSR0), timer_baseaddr + TCSR0); 153 } 154 155 static irqreturn_t timer_interrupt(int irq, void *dev_id) 156 { 157 struct clock_event_device *evt = &clockevent_xilinx_timer; 158 #ifdef CONFIG_HEART_BEAT 159 microblaze_heartbeat(); 160 #endif 161 timer_ack(); 162 evt->event_handler(evt); 163 return IRQ_HANDLED; 164 } 165 166 static struct irqaction timer_irqaction = { 167 .handler = timer_interrupt, 168 .flags = IRQF_TIMER, 169 .name = "timer", 170 .dev_id = &clockevent_xilinx_timer, 171 }; 172 173 static __init void xilinx_clockevent_init(void) 174 { 175 clockevent_xilinx_timer.mult = 176 div_sc(timer_clock_freq, NSEC_PER_SEC, 177 clockevent_xilinx_timer.shift); 178 clockevent_xilinx_timer.max_delta_ns = 179 clockevent_delta2ns((u32)~0, &clockevent_xilinx_timer); 180 clockevent_xilinx_timer.min_delta_ns = 181 clockevent_delta2ns(1, &clockevent_xilinx_timer); 182 clockevent_xilinx_timer.cpumask = cpumask_of(0); 183 clockevents_register_device(&clockevent_xilinx_timer); 184 } 185 186 static u64 xilinx_clock_read(void) 187 { 188 return read_fn(timer_baseaddr + TCR1); 189 } 190 191 static cycle_t xilinx_read(struct clocksource *cs) 192 { 193 /* reading actual value of timer 1 */ 194 return (cycle_t)xilinx_clock_read(); 195 } 196 197 static struct timecounter xilinx_tc = { 198 .cc = NULL, 199 }; 200 201 static cycle_t xilinx_cc_read(const struct cyclecounter *cc) 202 { 203 return xilinx_read(NULL); 204 } 205 206 static struct cyclecounter xilinx_cc = { 207 .read = xilinx_cc_read, 208 .mask = CLOCKSOURCE_MASK(32), 209 .shift = 8, 210 }; 211 212 static int __init init_xilinx_timecounter(void) 213 { 214 xilinx_cc.mult = div_sc(timer_clock_freq, NSEC_PER_SEC, 215 xilinx_cc.shift); 216 217 timecounter_init(&xilinx_tc, &xilinx_cc, sched_clock()); 218 219 return 0; 220 } 221 222 static struct clocksource clocksource_microblaze = { 223 .name = "xilinx_clocksource", 224 .rating = 300, 225 .read = xilinx_read, 226 .mask = CLOCKSOURCE_MASK(32), 227 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 228 }; 229 230 static int __init xilinx_clocksource_init(void) 231 { 232 if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq)) 233 panic("failed to register clocksource"); 234 235 /* stop timer1 */ 236 write_fn(read_fn(timer_baseaddr + TCSR1) & ~TCSR_ENT, 237 timer_baseaddr + TCSR1); 238 /* start timer1 - up counting without interrupt */ 239 write_fn(TCSR_TINT|TCSR_ENT|TCSR_ARHT, timer_baseaddr + TCSR1); 240 241 /* register timecounter - for ftrace support */ 242 init_xilinx_timecounter(); 243 return 0; 244 } 245 246 static void __init xilinx_timer_init(struct device_node *timer) 247 { 248 struct clk *clk; 249 static int initialized; 250 u32 irq; 251 u32 timer_num = 1; 252 253 if (initialized) 254 return; 255 256 initialized = 1; 257 258 timer_baseaddr = of_iomap(timer, 0); 259 if (!timer_baseaddr) { 260 pr_err("ERROR: invalid timer base address\n"); 261 BUG(); 262 } 263 264 write_fn = timer_write32; 265 read_fn = timer_read32; 266 267 write_fn(TCSR_MDT, timer_baseaddr + TCSR0); 268 if (!(read_fn(timer_baseaddr + TCSR0) & TCSR_MDT)) { 269 write_fn = timer_write32_be; 270 read_fn = timer_read32_be; 271 } 272 273 irq = irq_of_parse_and_map(timer, 0); 274 275 of_property_read_u32(timer, "xlnx,one-timer-only", &timer_num); 276 if (timer_num) { 277 pr_emerg("Please enable two timers in HW\n"); 278 BUG(); 279 } 280 281 pr_info("%s: irq=%d\n", timer->full_name, irq); 282 283 clk = of_clk_get(timer, 0); 284 if (IS_ERR(clk)) { 285 pr_err("ERROR: timer CCF input clock not found\n"); 286 /* If there is clock-frequency property than use it */ 287 of_property_read_u32(timer, "clock-frequency", 288 &timer_clock_freq); 289 } else { 290 timer_clock_freq = clk_get_rate(clk); 291 } 292 293 if (!timer_clock_freq) { 294 pr_err("ERROR: Using CPU clock frequency\n"); 295 timer_clock_freq = cpuinfo.cpu_clock_freq; 296 } 297 298 freq_div_hz = timer_clock_freq / HZ; 299 300 setup_irq(irq, &timer_irqaction); 301 #ifdef CONFIG_HEART_BEAT 302 microblaze_setup_heartbeat(); 303 #endif 304 xilinx_clocksource_init(); 305 xilinx_clockevent_init(); 306 307 sched_clock_register(xilinx_clock_read, 32, timer_clock_freq); 308 } 309 310 CLOCKSOURCE_OF_DECLARE(xilinx_timer, "xlnx,xps-timer-1.00.a", 311 xilinx_timer_init); 312