1 /* 2 * Copyright 2016 Google Inc. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <errno.h> 10 #include <timer.h> 11 #include <asm/io.h> 12 #include <asm/arch/timer.h> 13 14 DECLARE_GLOBAL_DATA_PTR; 15 16 #define AST_TICK_TIMER 1 17 #define AST_TMC_RELOAD_VAL 0xffffffff 18 19 struct ast_timer_priv { 20 struct ast_timer *regs; 21 struct ast_timer_counter *tmc; 22 }; 23 24 static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer, 25 int n) 26 { 27 if (n > 3) 28 return &timer->timers2[n - 4]; 29 else 30 return &timer->timers1[n - 1]; 31 } 32 33 static int ast_timer_probe(struct udevice *dev) 34 { 35 struct ast_timer_priv *priv = dev_get_priv(dev); 36 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); 37 38 writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val); 39 40 /* 41 * Stop the timer. This will also load reload_val into 42 * the status register. 43 */ 44 clrbits_le32(&priv->regs->ctrl1, 45 AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER)); 46 /* Start the timer from the fixed 1MHz clock. */ 47 setbits_le32(&priv->regs->ctrl1, 48 (AST_TMC_EN | AST_TMC_1MHZ) << 49 AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER)); 50 51 uc_priv->clock_rate = AST_TMC_RATE; 52 53 return 0; 54 } 55 56 static int ast_timer_get_count(struct udevice *dev, u64 *count) 57 { 58 struct ast_timer_priv *priv = dev_get_priv(dev); 59 60 *count = AST_TMC_RELOAD_VAL - readl(&priv->tmc->status); 61 62 return 0; 63 } 64 65 static int ast_timer_ofdata_to_platdata(struct udevice *dev) 66 { 67 struct ast_timer_priv *priv = dev_get_priv(dev); 68 69 priv->regs = devfdt_get_addr_ptr(dev); 70 if (IS_ERR(priv->regs)) 71 return PTR_ERR(priv->regs); 72 73 priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER); 74 75 return 0; 76 } 77 78 static const struct timer_ops ast_timer_ops = { 79 .get_count = ast_timer_get_count, 80 }; 81 82 static const struct udevice_id ast_timer_ids[] = { 83 { .compatible = "aspeed,ast2500-timer" }, 84 { .compatible = "aspeed,ast2400-timer" }, 85 { } 86 }; 87 88 U_BOOT_DRIVER(ast_timer) = { 89 .name = "ast_timer", 90 .id = UCLASS_TIMER, 91 .of_match = ast_timer_ids, 92 .probe = ast_timer_probe, 93 .priv_auto_alloc_size = sizeof(struct ast_timer_priv), 94 .ofdata_to_platdata = ast_timer_ofdata_to_platdata, 95 .ops = &ast_timer_ops, 96 .flags = DM_FLAG_PRE_RELOC, 97 }; 98