1 /* 2 * Copyright 2017 Google, Inc 3 * 4 * SPDX-License-Identifier: GPL-2.0 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <misc.h> 10 #include <reset.h> 11 #include <reset-uclass.h> 12 #include <wdt.h> 13 #include <asm/io.h> 14 #include <asm/arch/scu_ast2500.h> 15 #include <asm/arch/wdt.h> 16 17 DECLARE_GLOBAL_DATA_PTR; 18 19 struct ast2500_reset_priv { 20 /* WDT used to perform resets. */ 21 struct udevice *wdt; 22 struct ast2500_scu *scu; 23 }; 24 25 static int ast2500_ofdata_to_platdata(struct udevice *dev) 26 { 27 struct ast2500_reset_priv *priv = dev_get_priv(dev); 28 int ret; 29 30 ret = uclass_get_device_by_phandle(UCLASS_WDT, dev, "aspeed,wdt", 31 &priv->wdt); 32 if (ret) { 33 debug("%s: can't find WDT for reset controller", __func__); 34 return ret; 35 } 36 37 return 0; 38 } 39 40 static int ast2500_reset_assert(struct reset_ctl *reset_ctl) 41 { 42 struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev); 43 u32 reset_mode, reset_mask; 44 bool reset_sdram; 45 int ret; 46 47 /* 48 * To reset SDRAM, a specifal flag in SYSRESET register 49 * needs to be enabled first 50 */ 51 reset_mode = ast_reset_mode_from_flags(reset_ctl->id); 52 reset_mask = ast_reset_mask_from_flags(reset_ctl->id); 53 reset_sdram = reset_mode == WDT_CTRL_RESET_SOC && 54 (reset_mask & WDT_RESET_SDRAM); 55 56 if (reset_sdram) { 57 ast_scu_unlock(priv->scu); 58 setbits_le32(&priv->scu->sysreset_ctrl1, 59 SCU_SYSRESET_SDRAM_WDT); 60 ret = wdt_expire_now(priv->wdt, reset_ctl->id); 61 clrbits_le32(&priv->scu->sysreset_ctrl1, 62 SCU_SYSRESET_SDRAM_WDT); 63 ast_scu_lock(priv->scu); 64 } else { 65 ret = wdt_expire_now(priv->wdt, reset_ctl->id); 66 } 67 68 return ret; 69 } 70 71 static int ast2500_reset_request(struct reset_ctl *reset_ctl) 72 { 73 debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl, 74 reset_ctl->dev, reset_ctl->id); 75 76 return 0; 77 } 78 79 static int ast2500_reset_probe(struct udevice *dev) 80 { 81 struct ast2500_reset_priv *priv = dev_get_priv(dev); 82 83 priv->scu = ast_get_scu(); 84 85 return 0; 86 } 87 88 static const struct udevice_id ast2500_reset_ids[] = { 89 { .compatible = "aspeed,ast2500-reset" }, 90 { } 91 }; 92 93 struct reset_ops ast2500_reset_ops = { 94 .rst_assert = ast2500_reset_assert, 95 .request = ast2500_reset_request, 96 }; 97 98 U_BOOT_DRIVER(ast2500_reset) = { 99 .name = "ast2500_reset", 100 .id = UCLASS_RESET, 101 .of_match = ast2500_reset_ids, 102 .probe = ast2500_reset_probe, 103 .ops = &ast2500_reset_ops, 104 .ofdata_to_platdata = ast2500_ofdata_to_platdata, 105 .priv_auto_alloc_size = sizeof(struct ast2500_reset_priv), 106 }; 107