1 /* 2 * TI OMAP timer driver 3 * 4 * Copyright (C) 2015, Texas Instruments, Incorporated 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include <common.h> 10 #include <dm.h> 11 #include <errno.h> 12 #include <timer.h> 13 #include <asm/io.h> 14 #include <asm/arch/clock.h> 15 16 DECLARE_GLOBAL_DATA_PTR; 17 18 /* Timer register bits */ 19 #define TCLR_START BIT(0) /* Start=1 */ 20 #define TCLR_AUTO_RELOAD BIT(1) /* Auto reload */ 21 #define TCLR_PRE_EN BIT(5) /* Pre-scaler enable */ 22 #define TCLR_PTV_SHIFT (2) /* Pre-scaler shift value */ 23 24 #define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV)) 25 26 struct omap_gptimer_regs { 27 unsigned int tidr; /* offset 0x00 */ 28 unsigned char res1[12]; 29 unsigned int tiocp_cfg; /* offset 0x10 */ 30 unsigned char res2[12]; 31 unsigned int tier; /* offset 0x20 */ 32 unsigned int tistatr; /* offset 0x24 */ 33 unsigned int tistat; /* offset 0x28 */ 34 unsigned int tisr; /* offset 0x2c */ 35 unsigned int tcicr; /* offset 0x30 */ 36 unsigned int twer; /* offset 0x34 */ 37 unsigned int tclr; /* offset 0x38 */ 38 unsigned int tcrr; /* offset 0x3c */ 39 unsigned int tldr; /* offset 0x40 */ 40 unsigned int ttgr; /* offset 0x44 */ 41 unsigned int twpc; /* offset 0x48 */ 42 unsigned int tmar; /* offset 0x4c */ 43 unsigned int tcar1; /* offset 0x50 */ 44 unsigned int tscir; /* offset 0x54 */ 45 unsigned int tcar2; /* offset 0x58 */ 46 }; 47 48 /* Omap Timer Priv */ 49 struct omap_timer_priv { 50 struct omap_gptimer_regs *regs; 51 }; 52 53 static int omap_timer_get_count(struct udevice *dev, u64 *count) 54 { 55 struct omap_timer_priv *priv = dev_get_priv(dev); 56 57 *count = readl(&priv->regs->tcrr); 58 59 return 0; 60 } 61 62 static int omap_timer_probe(struct udevice *dev) 63 { 64 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); 65 struct omap_timer_priv *priv = dev_get_priv(dev); 66 67 uc_priv->clock_rate = TIMER_CLOCK; 68 69 /* start the counter ticking up, reload value on overflow */ 70 writel(0, &priv->regs->tldr); 71 /* enable timer */ 72 writel((CONFIG_SYS_PTV << 2) | TCLR_PRE_EN | TCLR_AUTO_RELOAD | 73 TCLR_START, &priv->regs->tclr); 74 75 return 0; 76 } 77 78 static int omap_timer_ofdata_to_platdata(struct udevice *dev) 79 { 80 struct omap_timer_priv *priv = dev_get_priv(dev); 81 82 priv->regs = map_physmem(devfdt_get_addr(dev), 83 sizeof(struct omap_gptimer_regs), MAP_NOCACHE); 84 85 return 0; 86 } 87 88 89 static const struct timer_ops omap_timer_ops = { 90 .get_count = omap_timer_get_count, 91 }; 92 93 static const struct udevice_id omap_timer_ids[] = { 94 { .compatible = "ti,am335x-timer" }, 95 { .compatible = "ti,am4372-timer" }, 96 { .compatible = "ti,omap5430-timer" }, 97 {} 98 }; 99 100 U_BOOT_DRIVER(omap_timer) = { 101 .name = "omap_timer", 102 .id = UCLASS_TIMER, 103 .of_match = omap_timer_ids, 104 .ofdata_to_platdata = omap_timer_ofdata_to_platdata, 105 .priv_auto_alloc_size = sizeof(struct omap_timer_priv), 106 .probe = omap_timer_probe, 107 .ops = &omap_timer_ops, 108 .flags = DM_FLAG_PRE_RELOC, 109 }; 110