1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) Siemens AG, 2020
4 *
5 * Authors:
6 * Jan Kiszka <jan.kiszka@siemens.com>
7 *
8 * Derived from linux/drivers/watchdog/rti_wdt.c
9 */
10
11 #include <common.h>
12 #include <clk.h>
13 #include <dm.h>
14 #include <dm/device_compat.h>
15 #include <power-domain.h>
16 #include <wdt.h>
17 #include <asm/io.h>
18 #include <remoteproc.h>
19
20 /* Timer register set definition */
21 #define RTIDWDCTRL 0x90
22 #define RTIDWDPRLD 0x94
23 #define RTIWDSTATUS 0x98
24 #define RTIWDKEY 0x9c
25 #define RTIDWDCNTR 0xa0
26 #define RTIWWDRXCTRL 0xa4
27 #define RTIWWDSIZECTRL 0xa8
28
29 #define RTIWWDRX_NMI 0xa
30
31 #define RTIWWDSIZE_50P 0x50
32
33 #define WDENABLE_KEY 0xa98559da
34
35 #define WDKEY_SEQ0 0xe51a
36 #define WDKEY_SEQ1 0xa35c
37
38 #define WDT_PRELOAD_SHIFT 13
39
40 #define WDT_PRELOAD_MAX 0xfff
41
42 struct rti_wdt_priv {
43 phys_addr_t regs;
44 unsigned int clk_khz;
45 };
46
47 #ifdef CONFIG_WDT_K3_RTI_LOAD_FW
48 #define RTI_WDT_FIT_PATH "/fit-images/k3-rti-wdt-firmware"
49
rti_wdt_load_fw(struct udevice * dev)50 static int rti_wdt_load_fw(struct udevice *dev)
51 {
52 struct udevice *rproc_dev;
53 int primary_core, ret;
54 u32 cluster_mode;
55 ofnode node;
56 u64 rti_wdt_fw;
57 u32 rti_wdt_fw_size;
58
59 node = ofnode_path(RTI_WDT_FIT_PATH);
60 if (!ofnode_valid(node))
61 goto fit_error;
62
63 ret = ofnode_read_u64(node, "load", &rti_wdt_fw);
64 if (ret)
65 goto fit_error;
66 ret = ofnode_read_u32(node, "size", &rti_wdt_fw_size);
67 if (ret)
68 goto fit_error;
69
70 node = ofnode_by_compatible(ofnode_null(), "ti,am654-r5fss");
71 if (!ofnode_valid(node))
72 goto dt_error;
73
74 ret = ofnode_read_u32(node, "ti,cluster-mode", &cluster_mode);
75 if (ret)
76 cluster_mode = 1;
77
78 node = ofnode_by_compatible(node, "ti,am654-r5f");
79 if (!ofnode_valid(node))
80 goto dt_error;
81
82 ret = uclass_get_device_by_ofnode(UCLASS_REMOTEPROC, node, &rproc_dev);
83 if (ret)
84 return ret;
85
86 primary_core = dev_seq(rproc_dev);
87
88 ret = rproc_dev_init(primary_core);
89 if (ret)
90 goto fw_error;
91
92 if (cluster_mode == 1) {
93 ret = rproc_dev_init(primary_core + 1);
94 if (ret)
95 goto fw_error;
96 }
97
98 ret = rproc_load(primary_core, (ulong)rti_wdt_fw,
99 rti_wdt_fw_size);
100 if (ret)
101 goto fw_error;
102
103 ret = rproc_start(primary_core);
104 if (ret)
105 goto fw_error;
106
107 return 0;
108
109 fit_error:
110 dev_err(dev, "No loadable firmware found under %s\n", RTI_WDT_FIT_PATH);
111 return -ENOENT;
112
113 dt_error:
114 dev_err(dev, "No compatible firmware target processor found\n");
115 return -ENODEV;
116
117 fw_error:
118 dev_err(dev, "Failed to load watchdog firmware into remote processor %d\n",
119 primary_core);
120 return ret;
121 }
122 #else
rti_wdt_load_fw(struct udevice * dev)123 static inline int rti_wdt_load_fw(struct udevice *dev)
124 {
125 return 0;
126 }
127 #endif
128
rti_wdt_start(struct udevice * dev,u64 timeout_ms,ulong flags)129 static int rti_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
130 {
131 struct rti_wdt_priv *priv = dev_get_priv(dev);
132 u32 timer_margin;
133 int ret;
134
135 if (readl(priv->regs + RTIDWDCTRL) == WDENABLE_KEY)
136 return -EBUSY;
137
138 ret = rti_wdt_load_fw(dev);
139 if (ret < 0)
140 return ret;
141
142 timer_margin = timeout_ms * priv->clk_khz / 1000;
143 timer_margin >>= WDT_PRELOAD_SHIFT;
144 if (timer_margin > WDT_PRELOAD_MAX)
145 timer_margin = WDT_PRELOAD_MAX;
146
147 writel(timer_margin, priv->regs + RTIDWDPRLD);
148 writel(RTIWWDRX_NMI, priv->regs + RTIWWDRXCTRL);
149 writel(RTIWWDSIZE_50P, priv->regs + RTIWWDSIZECTRL);
150
151 readl(priv->regs + RTIWWDSIZECTRL);
152
153 writel(WDENABLE_KEY, priv->regs + RTIDWDCTRL);
154
155 return 0;
156 }
157
rti_wdt_reset(struct udevice * dev)158 static int rti_wdt_reset(struct udevice *dev)
159 {
160 struct rti_wdt_priv *priv = dev_get_priv(dev);
161 u32 prld;
162
163 /* Make sure we do not reset too early */
164 prld = readl(priv->regs + RTIDWDPRLD) << WDT_PRELOAD_SHIFT;
165 if (readl(priv->regs + RTIDWDCNTR) >= prld / 2)
166 return -EPERM;
167
168 writel(WDKEY_SEQ0, priv->regs + RTIWDKEY);
169 writel(WDKEY_SEQ1, priv->regs + RTIWDKEY);
170
171 return 0;
172 }
173
rti_wdt_probe(struct udevice * dev)174 static int rti_wdt_probe(struct udevice *dev)
175 {
176 struct rti_wdt_priv *priv = dev_get_priv(dev);
177 struct clk clk;
178 int ret;
179
180 priv->regs = devfdt_get_addr(dev);
181 if (!priv->regs)
182 return -EINVAL;
183
184 ret = clk_get_by_index(dev, 0, &clk);
185 if (ret)
186 return ret;
187
188 priv->clk_khz = clk_get_rate(&clk);
189
190 return 0;
191 }
192
193 static const struct wdt_ops rti_wdt_ops = {
194 .start = rti_wdt_start,
195 .reset = rti_wdt_reset,
196 };
197
198 static const struct udevice_id rti_wdt_ids[] = {
199 { .compatible = "ti,j7-rti-wdt" },
200 { }
201 };
202
203 U_BOOT_DRIVER(rti_wdt) = {
204 .name = "rti_wdt",
205 .id = UCLASS_WDT,
206 .of_match = rti_wdt_ids,
207 .ops = &rti_wdt_ops,
208 .probe = rti_wdt_probe,
209 .priv_auto = sizeof(struct rti_wdt_priv),
210 .flags = DM_FLAG_LEAVE_PD_ON,
211 };
212