1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Texas Instruments DRA7 reset driver
4 *
5 * Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
6 * Author: Keerthy <j-keerthy@ti.com>
7 */
8
9 #include <asm/io.h>
10 #include <dm.h>
11 #include <reset-uclass.h>
12 #include <dm/device_compat.h>
13
14 struct dra7_reset_priv {
15 u32 rstctrl;
16 u32 rstst;
17 u8 nreset;
18 };
19
dra7_reset_rmw(u32 addr,u32 value,u32 mask)20 static inline void dra7_reset_rmw(u32 addr, u32 value, u32 mask)
21 {
22 writel(((readl(addr) & (~mask)) | (value & mask)), addr);
23 }
24
dra7_reset_deassert(struct reset_ctl * reset_ctl)25 static int dra7_reset_deassert(struct reset_ctl *reset_ctl)
26 {
27 struct dra7_reset_priv *priv = dev_get_priv(reset_ctl->dev);
28 int mask = 1 << reset_ctl->id;
29
30 if (reset_ctl->id < 0 || reset_ctl->id >= priv->nreset)
31 return -EINVAL;
32
33 dra7_reset_rmw(priv->rstctrl, 0x0, mask);
34
35 while ((readl(priv->rstst) & mask) != mask)
36 ;
37
38 return 0;
39 }
40
dra7_reset_assert(struct reset_ctl * reset_ctl)41 static int dra7_reset_assert(struct reset_ctl *reset_ctl)
42 {
43 struct dra7_reset_priv *priv = dev_get_priv(reset_ctl->dev);
44 int mask = 1 << reset_ctl->id;
45
46 if (reset_ctl->id < 0 || reset_ctl->id >= priv->nreset)
47 return -EINVAL;
48
49 dra7_reset_rmw(priv->rstctrl, mask, 0x0);
50
51 return 0;
52 }
53
54 struct reset_ops dra7_reset_ops = {
55 .rst_assert = dra7_reset_assert,
56 .rst_deassert = dra7_reset_deassert,
57 };
58
59 static const struct udevice_id dra7_reset_ids[] = {
60 { .compatible = "ti,dra7-reset" },
61 { }
62 };
63
dra7_reset_probe(struct udevice * dev)64 static int dra7_reset_probe(struct udevice *dev)
65 {
66 struct dra7_reset_priv *priv = dev_get_priv(dev);
67
68 priv->rstctrl = dev_read_addr(dev);
69 priv->rstst = priv->rstctrl + 0x4;
70 priv->nreset = dev_read_u32_default(dev, "ti,nresets", 1);
71
72 dev_info(dev, "dra7-reset successfully probed %s\n", dev->name);
73
74 return 0;
75 }
76
77 U_BOOT_DRIVER(dra7_reset) = {
78 .name = "dra7_reset",
79 .id = UCLASS_RESET,
80 .of_match = dra7_reset_ids,
81 .probe = dra7_reset_probe,
82 .ops = &dra7_reset_ops,
83 .priv_auto = sizeof(struct dra7_reset_priv),
84 };
85