1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3 * Copyright (C) 2018 Amarula Solutions.
4 * Author: Jagan Teki <jagan@amarulasolutions.com>
5 */
6
7 #include <dm.h>
8 #include <errno.h>
9 #include <log.h>
10 #include <malloc.h>
11 #include <reset-uclass.h>
12 #include <asm/io.h>
13 #include <clk/sunxi.h>
14 #include <linux/bitops.h>
15 #include <linux/log2.h>
16
plat_to_reset(struct ccu_plat * plat,unsigned long id)17 static const struct ccu_reset *plat_to_reset(struct ccu_plat *plat,
18 unsigned long id)
19 {
20 return &plat->desc->resets[id];
21 }
22
sunxi_reset_request(struct reset_ctl * reset_ctl)23 static int sunxi_reset_request(struct reset_ctl *reset_ctl)
24 {
25 struct ccu_plat *plat = dev_get_plat(reset_ctl->dev);
26
27 debug("%s: (RST#%ld)\n", __func__, reset_ctl->id);
28
29 if (reset_ctl->id >= plat->desc->num_resets)
30 return -EINVAL;
31
32 return 0;
33 }
34
sunxi_set_reset(struct reset_ctl * reset_ctl,bool on)35 static int sunxi_set_reset(struct reset_ctl *reset_ctl, bool on)
36 {
37 struct ccu_plat *plat = dev_get_plat(reset_ctl->dev);
38 const struct ccu_reset *reset = plat_to_reset(plat, reset_ctl->id);
39 u32 reg;
40
41 if (!(reset->flags & CCU_RST_F_IS_VALID)) {
42 printf("%s: (RST#%ld) unhandled\n", __func__, reset_ctl->id);
43 return 0;
44 }
45
46 debug("%s: (RST#%ld) off#0x%x, BIT(%d)\n", __func__,
47 reset_ctl->id, reset->off, ilog2(reset->bit));
48
49 reg = readl(plat->base + reset->off);
50 if (on)
51 reg |= reset->bit;
52 else
53 reg &= ~reset->bit;
54
55 writel(reg, plat->base + reset->off);
56
57 return 0;
58 }
59
sunxi_reset_assert(struct reset_ctl * reset_ctl)60 static int sunxi_reset_assert(struct reset_ctl *reset_ctl)
61 {
62 return sunxi_set_reset(reset_ctl, false);
63 }
64
sunxi_reset_deassert(struct reset_ctl * reset_ctl)65 static int sunxi_reset_deassert(struct reset_ctl *reset_ctl)
66 {
67 return sunxi_set_reset(reset_ctl, true);
68 }
69
70 struct reset_ops sunxi_reset_ops = {
71 .request = sunxi_reset_request,
72 .rst_assert = sunxi_reset_assert,
73 .rst_deassert = sunxi_reset_deassert,
74 };
75
76 U_BOOT_DRIVER(sunxi_reset) = {
77 .name = "sunxi_reset",
78 .id = UCLASS_RESET,
79 .ops = &sunxi_reset_ops,
80 };
81