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/clk.h> 16 #include <linux/clockchips.h> 17 #include <linux/of_address.h> 18 #include <linux/of_irq.h> 19 #include <asm/cpuinfo.h> 20 #include <linux/cnt32_to_63.h> 21 22 static void __iomem *timer_baseaddr; 23 24 static unsigned int freq_div_hz; 25 static unsigned int timer_clock_freq; 26 27 #define TCSR0 (0x00) 28 #define TLR0 (0x04) 29 #define TCR0 (0x08) 30 #define TCSR1 (0x10) 31 #define TLR1 (0x14) 32 #define TCR1 (0x18) 33 34 #define TCSR_MDT (1<<0) 35 #define TCSR_UDT (1<<1) 36 #define TCSR_GENT (1<<2) 37 #define TCSR_CAPT (1<<3) 38 #define TCSR_ARHT (1<<4) 39 #define TCSR_LOAD (1<<5) 40 #define TCSR_ENIT (1<<6) 41 #define TCSR_ENT (1<<7) 42 #define TCSR_TINT (1<<8) 43 #define TCSR_PWMA (1<<9) 44 #define TCSR_ENALL (1<<10) 45 46 static inline void xilinx_timer0_stop(void) 47 { 48 out_be32(timer_baseaddr + TCSR0, 49 in_be32(timer_baseaddr + TCSR0) & ~TCSR_ENT); 50 } 51 52 static inline void xilinx_timer0_start_periodic(unsigned long load_val) 53 { 54 if (!load_val) 55 load_val = 1; 56 /* loading value to timer reg */ 57 out_be32(timer_baseaddr + TLR0, load_val); 58 59 /* load the initial value */ 60 out_be32(timer_baseaddr + TCSR0, TCSR_LOAD); 61 62 /* see timer data sheet for detail 63 * !ENALL - don't enable 'em all 64 * !PWMA - disable pwm 65 * TINT - clear interrupt status 66 * ENT- enable timer itself 67 * ENIT - enable interrupt 68 * !LOAD - clear the bit to let go 69 * ARHT - auto reload 70 * !CAPT - no external trigger 71 * !GENT - no external signal 72 * UDT - set the timer as down counter 73 * !MDT0 - generate mode 74 */ 75 out_be32(timer_baseaddr + TCSR0, 76 TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT); 77 } 78 79 static inline void xilinx_timer0_start_oneshot(unsigned long load_val) 80 { 81 if (!load_val) 82 load_val = 1; 83 /* loading value to timer reg */ 84 out_be32(timer_baseaddr + TLR0, load_val); 85 86 /* load the initial value */ 87 out_be32(timer_baseaddr + TCSR0, TCSR_LOAD); 88 89 out_be32(timer_baseaddr + TCSR0, 90 TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT); 91 } 92 93 static int xilinx_timer_set_next_event(unsigned long delta, 94 struct clock_event_device *dev) 95 { 96 pr_debug("%s: next event, delta %x\n", __func__, (u32)delta); 97 xilinx_timer0_start_oneshot(delta); 98 return 0; 99 } 100 101 static void xilinx_timer_set_mode(enum clock_event_mode mode, 102 struct clock_event_device *evt) 103 { 104 switch (mode) { 105 case CLOCK_EVT_MODE_PERIODIC: 106 pr_info("%s: periodic\n", __func__); 107 xilinx_timer0_start_periodic(freq_div_hz); 108 break; 109 case CLOCK_EVT_MODE_ONESHOT: 110 pr_info("%s: oneshot\n", __func__); 111 break; 112 case CLOCK_EVT_MODE_UNUSED: 113 pr_info("%s: unused\n", __func__); 114 break; 115 case CLOCK_EVT_MODE_SHUTDOWN: 116 pr_info("%s: shutdown\n", __func__); 117 xilinx_timer0_stop(); 118 break; 119 case CLOCK_EVT_MODE_RESUME: 120 pr_info("%s: resume\n", __func__); 121 break; 122 } 123 } 124 125 static struct clock_event_device clockevent_xilinx_timer = { 126 .name = "xilinx_clockevent", 127 .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, 128 .shift = 8, 129 .rating = 300, 130 .set_next_event = xilinx_timer_set_next_event, 131 .set_mode = xilinx_timer_set_mode, 132 }; 133 134 static inline void timer_ack(void) 135 { 136 out_be32(timer_baseaddr + TCSR0, in_be32(timer_baseaddr + TCSR0)); 137 } 138 139 static irqreturn_t timer_interrupt(int irq, void *dev_id) 140 { 141 struct clock_event_device *evt = &clockevent_xilinx_timer; 142 #ifdef CONFIG_HEART_BEAT 143 heartbeat(); 144 #endif 145 timer_ack(); 146 evt->event_handler(evt); 147 return IRQ_HANDLED; 148 } 149 150 static struct irqaction timer_irqaction = { 151 .handler = timer_interrupt, 152 .flags = IRQF_TIMER, 153 .name = "timer", 154 .dev_id = &clockevent_xilinx_timer, 155 }; 156 157 static __init void xilinx_clockevent_init(void) 158 { 159 clockevent_xilinx_timer.mult = 160 div_sc(timer_clock_freq, NSEC_PER_SEC, 161 clockevent_xilinx_timer.shift); 162 clockevent_xilinx_timer.max_delta_ns = 163 clockevent_delta2ns((u32)~0, &clockevent_xilinx_timer); 164 clockevent_xilinx_timer.min_delta_ns = 165 clockevent_delta2ns(1, &clockevent_xilinx_timer); 166 clockevent_xilinx_timer.cpumask = cpumask_of(0); 167 clockevents_register_device(&clockevent_xilinx_timer); 168 } 169 170 static cycle_t xilinx_read(struct clocksource *cs) 171 { 172 /* reading actual value of timer 1 */ 173 return (cycle_t) (in_be32(timer_baseaddr + TCR1)); 174 } 175 176 static struct timecounter xilinx_tc = { 177 .cc = NULL, 178 }; 179 180 static cycle_t xilinx_cc_read(const struct cyclecounter *cc) 181 { 182 return xilinx_read(NULL); 183 } 184 185 static struct cyclecounter xilinx_cc = { 186 .read = xilinx_cc_read, 187 .mask = CLOCKSOURCE_MASK(32), 188 .shift = 8, 189 }; 190 191 static int __init init_xilinx_timecounter(void) 192 { 193 xilinx_cc.mult = div_sc(timer_clock_freq, NSEC_PER_SEC, 194 xilinx_cc.shift); 195 196 timecounter_init(&xilinx_tc, &xilinx_cc, sched_clock()); 197 198 return 0; 199 } 200 201 static struct clocksource clocksource_microblaze = { 202 .name = "xilinx_clocksource", 203 .rating = 300, 204 .read = xilinx_read, 205 .mask = CLOCKSOURCE_MASK(32), 206 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 207 }; 208 209 static int __init xilinx_clocksource_init(void) 210 { 211 if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq)) 212 panic("failed to register clocksource"); 213 214 /* stop timer1 */ 215 out_be32(timer_baseaddr + TCSR1, 216 in_be32(timer_baseaddr + TCSR1) & ~TCSR_ENT); 217 /* start timer1 - up counting without interrupt */ 218 out_be32(timer_baseaddr + TCSR1, TCSR_TINT|TCSR_ENT|TCSR_ARHT); 219 220 /* register timecounter - for ftrace support */ 221 init_xilinx_timecounter(); 222 return 0; 223 } 224 225 /* 226 * We have to protect accesses before timer initialization 227 * and return 0 for sched_clock function below. 228 */ 229 static int timer_initialized; 230 231 static void __init xilinx_timer_init(struct device_node *timer) 232 { 233 u32 irq; 234 u32 timer_num = 1; 235 int ret; 236 237 timer_baseaddr = of_iomap(timer, 0); 238 if (!timer_baseaddr) { 239 pr_err("ERROR: invalid timer base address\n"); 240 BUG(); 241 } 242 243 irq = irq_of_parse_and_map(timer, 0); 244 245 of_property_read_u32(timer, "xlnx,one-timer-only", &timer_num); 246 if (timer_num) { 247 pr_emerg("Please enable two timers in HW\n"); 248 BUG(); 249 } 250 251 pr_info("%s: irq=%d\n", timer->full_name, irq); 252 253 /* If there is clock-frequency property than use it */ 254 ret = of_property_read_u32(timer, "clock-frequency", &timer_clock_freq); 255 if (ret < 0) 256 timer_clock_freq = cpuinfo.cpu_clock_freq; 257 258 freq_div_hz = timer_clock_freq / HZ; 259 260 setup_irq(irq, &timer_irqaction); 261 #ifdef CONFIG_HEART_BEAT 262 setup_heartbeat(); 263 #endif 264 xilinx_clocksource_init(); 265 xilinx_clockevent_init(); 266 timer_initialized = 1; 267 } 268 269 unsigned long long notrace sched_clock(void) 270 { 271 if (timer_initialized) { 272 struct clocksource *cs = &clocksource_microblaze; 273 274 cycle_t cyc = cnt32_to_63(cs->read(NULL)) & LLONG_MAX; 275 return clocksource_cyc2ns(cyc, cs->mult, cs->shift); 276 } 277 return 0; 278 } 279 280 CLOCKSOURCE_OF_DECLARE(xilinx_timer, "xlnx,xps-timer-1.00.a", 281 xilinx_timer_init); 282