1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2000-2002 4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 5 * 6 * (C) Copyright 2004, Psyent Corporation <www.psyent.com> 7 * Scott McNutt <smcnutt@psyent.com> 8 */ 9 10 #include <common.h> 11 #include <dm.h> 12 #include <errno.h> 13 #include <timer.h> 14 #include <asm/io.h> 15 16 /* control register */ 17 #define ALTERA_TIMER_CONT BIT(1) /* Continuous mode */ 18 #define ALTERA_TIMER_START BIT(2) /* Start timer */ 19 #define ALTERA_TIMER_STOP BIT(3) /* Stop timer */ 20 21 struct altera_timer_regs { 22 u32 status; /* Timer status reg */ 23 u32 control; /* Timer control reg */ 24 u32 periodl; /* Timeout period low */ 25 u32 periodh; /* Timeout period high */ 26 u32 snapl; /* Snapshot low */ 27 u32 snaph; /* Snapshot high */ 28 }; 29 30 struct altera_timer_platdata { 31 struct altera_timer_regs *regs; 32 }; 33 34 static int altera_timer_get_count(struct udevice *dev, u64 *count) 35 { 36 struct altera_timer_platdata *plat = dev->platdata; 37 struct altera_timer_regs *const regs = plat->regs; 38 u32 val; 39 40 /* Trigger update */ 41 writel(0x0, ®s->snapl); 42 43 /* Read timer value */ 44 val = readl(®s->snapl) & 0xffff; 45 val |= (readl(®s->snaph) & 0xffff) << 16; 46 *count = timer_conv_64(~val); 47 48 return 0; 49 } 50 51 static int altera_timer_probe(struct udevice *dev) 52 { 53 struct altera_timer_platdata *plat = dev->platdata; 54 struct altera_timer_regs *const regs = plat->regs; 55 56 writel(0, ®s->status); 57 writel(0, ®s->control); 58 writel(ALTERA_TIMER_STOP, ®s->control); 59 60 writel(0xffff, ®s->periodl); 61 writel(0xffff, ®s->periodh); 62 writel(ALTERA_TIMER_CONT | ALTERA_TIMER_START, ®s->control); 63 64 return 0; 65 } 66 67 static int altera_timer_ofdata_to_platdata(struct udevice *dev) 68 { 69 struct altera_timer_platdata *plat = dev_get_platdata(dev); 70 71 plat->regs = map_physmem(devfdt_get_addr(dev), 72 sizeof(struct altera_timer_regs), 73 MAP_NOCACHE); 74 75 return 0; 76 } 77 78 static const struct timer_ops altera_timer_ops = { 79 .get_count = altera_timer_get_count, 80 }; 81 82 static const struct udevice_id altera_timer_ids[] = { 83 { .compatible = "altr,timer-1.0" }, 84 {} 85 }; 86 87 U_BOOT_DRIVER(altera_timer) = { 88 .name = "altera_timer", 89 .id = UCLASS_TIMER, 90 .of_match = altera_timer_ids, 91 .ofdata_to_platdata = altera_timer_ofdata_to_platdata, 92 .platdata_auto_alloc_size = sizeof(struct altera_timer_platdata), 93 .probe = altera_timer_probe, 94 .ops = &altera_timer_ops, 95 }; 96