1 /* 2 * (C) Copyright 2000-2002 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * (C) Copyright 2004, Psyent Corporation <www.psyent.com> 6 * Scott McNutt <smcnutt@psyent.com> 7 * 8 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 #include <common.h> 12 #include <dm.h> 13 #include <errno.h> 14 #include <timer.h> 15 #include <asm/io.h> 16 17 /* control register */ 18 #define ALTERA_TIMER_CONT BIT(1) /* Continuous mode */ 19 #define ALTERA_TIMER_START BIT(2) /* Start timer */ 20 #define ALTERA_TIMER_STOP BIT(3) /* Stop timer */ 21 22 struct altera_timer_regs { 23 u32 status; /* Timer status reg */ 24 u32 control; /* Timer control reg */ 25 u32 periodl; /* Timeout period low */ 26 u32 periodh; /* Timeout period high */ 27 u32 snapl; /* Snapshot low */ 28 u32 snaph; /* Snapshot high */ 29 }; 30 31 struct altera_timer_platdata { 32 struct altera_timer_regs *regs; 33 }; 34 35 static int altera_timer_get_count(struct udevice *dev, u64 *count) 36 { 37 struct altera_timer_platdata *plat = dev->platdata; 38 struct altera_timer_regs *const regs = plat->regs; 39 u32 val; 40 41 /* Trigger update */ 42 writel(0x0, ®s->snapl); 43 44 /* Read timer value */ 45 val = readl(®s->snapl) & 0xffff; 46 val |= (readl(®s->snaph) & 0xffff) << 16; 47 *count = timer_conv_64(~val); 48 49 return 0; 50 } 51 52 static int altera_timer_probe(struct udevice *dev) 53 { 54 struct altera_timer_platdata *plat = dev->platdata; 55 struct altera_timer_regs *const regs = plat->regs; 56 57 writel(0, ®s->status); 58 writel(0, ®s->control); 59 writel(ALTERA_TIMER_STOP, ®s->control); 60 61 writel(0xffff, ®s->periodl); 62 writel(0xffff, ®s->periodh); 63 writel(ALTERA_TIMER_CONT | ALTERA_TIMER_START, ®s->control); 64 65 return 0; 66 } 67 68 static int altera_timer_ofdata_to_platdata(struct udevice *dev) 69 { 70 struct altera_timer_platdata *plat = dev_get_platdata(dev); 71 72 plat->regs = map_physmem(devfdt_get_addr(dev), 73 sizeof(struct altera_timer_regs), 74 MAP_NOCACHE); 75 76 return 0; 77 } 78 79 static const struct timer_ops altera_timer_ops = { 80 .get_count = altera_timer_get_count, 81 }; 82 83 static const struct udevice_id altera_timer_ids[] = { 84 { .compatible = "altr,timer-1.0" }, 85 {} 86 }; 87 88 U_BOOT_DRIVER(altera_timer) = { 89 .name = "altera_timer", 90 .id = UCLASS_TIMER, 91 .of_match = altera_timer_ids, 92 .ofdata_to_platdata = altera_timer_ofdata_to_platdata, 93 .platdata_auto_alloc_size = sizeof(struct altera_timer_platdata), 94 .probe = altera_timer_probe, 95 .ops = &altera_timer_ops, 96 .flags = DM_FLAG_PRE_RELOC, 97 }; 98