1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright 2017 Google, Inc 4 */ 5 6 #include <common.h> 7 #include <dm.h> 8 #include <errno.h> 9 #include <wdt.h> 10 #include <asm/io.h> 11 #include <asm/arch/wdt.h> 12 13 #define WDT_AST2500 2500 14 #define WDT_AST2400 2400 15 16 struct ast_wdt_priv { 17 struct ast_wdt *regs; 18 }; 19 20 static int ast_wdt_start(struct udevice *dev, u64 timeout, ulong flags) 21 { 22 struct ast_wdt_priv *priv = dev_get_priv(dev); 23 ulong driver_data = dev_get_driver_data(dev); 24 u32 reset_mode = ast_reset_mode_from_flags(flags); 25 26 clrsetbits_le32(&priv->regs->ctrl, 27 WDT_CTRL_RESET_MASK << WDT_CTRL_RESET_MODE_SHIFT, 28 reset_mode << WDT_CTRL_RESET_MODE_SHIFT); 29 30 if (driver_data >= WDT_AST2500 && reset_mode == WDT_CTRL_RESET_SOC) 31 writel(ast_reset_mask_from_flags(flags), 32 &priv->regs->reset_mask); 33 34 writel((u32) timeout, &priv->regs->counter_reload_val); 35 writel(WDT_COUNTER_RESTART_VAL, &priv->regs->counter_restart); 36 /* 37 * Setting CLK1MHZ bit is just for compatibility with ast2400 part. 38 * On ast2500 watchdog timer clock is fixed at 1MHz and the bit is 39 * read-only 40 */ 41 setbits_le32(&priv->regs->ctrl, 42 WDT_CTRL_EN | WDT_CTRL_RESET | WDT_CTRL_CLK1MHZ); 43 44 return 0; 45 } 46 47 static int ast_wdt_stop(struct udevice *dev) 48 { 49 struct ast_wdt_priv *priv = dev_get_priv(dev); 50 51 clrbits_le32(&priv->regs->ctrl, WDT_CTRL_EN); 52 53 writel(WDT_RESET_DEFAULT, &priv->regs->reset_mask); 54 return 0; 55 } 56 57 static int ast_wdt_reset(struct udevice *dev) 58 { 59 struct ast_wdt_priv *priv = dev_get_priv(dev); 60 61 writel(WDT_COUNTER_RESTART_VAL, &priv->regs->counter_restart); 62 63 return 0; 64 } 65 66 static int ast_wdt_expire_now(struct udevice *dev, ulong flags) 67 { 68 struct ast_wdt_priv *priv = dev_get_priv(dev); 69 int ret; 70 71 ret = ast_wdt_start(dev, 1, flags); 72 if (ret) 73 return ret; 74 75 while (readl(&priv->regs->ctrl) & WDT_CTRL_EN) 76 ; 77 78 return ast_wdt_stop(dev); 79 } 80 81 static int ast_wdt_ofdata_to_platdata(struct udevice *dev) 82 { 83 struct ast_wdt_priv *priv = dev_get_priv(dev); 84 85 priv->regs = devfdt_get_addr_ptr(dev); 86 if (IS_ERR(priv->regs)) 87 return PTR_ERR(priv->regs); 88 89 return 0; 90 } 91 92 static const struct wdt_ops ast_wdt_ops = { 93 .start = ast_wdt_start, 94 .reset = ast_wdt_reset, 95 .stop = ast_wdt_stop, 96 .expire_now = ast_wdt_expire_now, 97 }; 98 99 static const struct udevice_id ast_wdt_ids[] = { 100 { .compatible = "aspeed,wdt", .data = WDT_AST2500 }, 101 { .compatible = "aspeed,ast2500-wdt", .data = WDT_AST2500 }, 102 { .compatible = "aspeed,ast2400-wdt", .data = WDT_AST2400 }, 103 {} 104 }; 105 106 static int ast_wdt_probe(struct udevice *dev) 107 { 108 debug("%s() wdt%u\n", __func__, dev->seq); 109 ast_wdt_stop(dev); 110 111 return 0; 112 } 113 114 U_BOOT_DRIVER(ast_wdt) = { 115 .name = "ast_wdt", 116 .id = UCLASS_WDT, 117 .of_match = ast_wdt_ids, 118 .probe = ast_wdt_probe, 119 .priv_auto_alloc_size = sizeof(struct ast_wdt_priv), 120 .ofdata_to_platdata = ast_wdt_ofdata_to_platdata, 121 .ops = &ast_wdt_ops, 122 .flags = DM_FLAG_PRE_RELOC, 123 }; 124