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