1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Socfpga Reset Controller Driver
4 *
5 * Copyright 2014 Steffen Trumtrar <s.trumtrar@pengutronix.de>
6 *
7 * based on
8 * Allwinner SoCs Reset Controller driver
9 *
10 * Copyright 2013 Maxime Ripard
11 *
12 * Maxime Ripard <maxime.ripard@free-electrons.com>
13 */
14
15 #include <common.h>
16 #include <dm.h>
17 #include <dm/of_access.h>
18 #include <reset-uclass.h>
19 #include <linux/bitops.h>
20 #include <linux/io.h>
21 #include <linux/sizes.h>
22
23 #define BANK_INCREMENT 4
24 #define NR_BANKS 8
25
26 struct socfpga_reset_data {
27 void __iomem *membase;
28 };
29
socfpga_reset_assert(struct reset_ctl * reset_ctl)30 static int socfpga_reset_assert(struct reset_ctl *reset_ctl)
31 {
32 struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
33 int id = reset_ctl->id;
34 int reg_width = sizeof(u32);
35 int bank = id / (reg_width * BITS_PER_BYTE);
36 int offset = id % (reg_width * BITS_PER_BYTE);
37
38 setbits_le32(data->membase + (bank * BANK_INCREMENT), BIT(offset));
39 return 0;
40 }
41
socfpga_reset_deassert(struct reset_ctl * reset_ctl)42 static int socfpga_reset_deassert(struct reset_ctl *reset_ctl)
43 {
44 struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
45 int id = reset_ctl->id;
46 int reg_width = sizeof(u32);
47 int bank = id / (reg_width * BITS_PER_BYTE);
48 int offset = id % (reg_width * BITS_PER_BYTE);
49
50 clrbits_le32(data->membase + (bank * BANK_INCREMENT), BIT(offset));
51 return 0;
52 }
53
socfpga_reset_request(struct reset_ctl * reset_ctl)54 static int socfpga_reset_request(struct reset_ctl *reset_ctl)
55 {
56 debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__,
57 reset_ctl, reset_ctl->dev, reset_ctl->id);
58
59 return 0;
60 }
61
socfpga_reset_free(struct reset_ctl * reset_ctl)62 static int socfpga_reset_free(struct reset_ctl *reset_ctl)
63 {
64 debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
65 reset_ctl->dev, reset_ctl->id);
66
67 return 0;
68 }
69
70 static const struct reset_ops socfpga_reset_ops = {
71 .request = socfpga_reset_request,
72 .free = socfpga_reset_free,
73 .rst_assert = socfpga_reset_assert,
74 .rst_deassert = socfpga_reset_deassert,
75 };
76
socfpga_reset_probe(struct udevice * dev)77 static int socfpga_reset_probe(struct udevice *dev)
78 {
79 struct socfpga_reset_data *data = dev_get_priv(dev);
80 const void *blob = gd->fdt_blob;
81 int node = dev_of_offset(dev);
82 u32 modrst_offset;
83
84 data->membase = devfdt_get_addr_ptr(dev);
85
86 modrst_offset = fdtdec_get_int(blob, node, "altr,modrst-offset", 0x10);
87 data->membase += modrst_offset;
88
89 return 0;
90 }
91
92 static const struct udevice_id socfpga_reset_match[] = {
93 { .compatible = "altr,rst-mgr" },
94 { /* sentinel */ },
95 };
96
97 U_BOOT_DRIVER(socfpga_reset) = {
98 .name = "socfpga-reset",
99 .id = UCLASS_RESET,
100 .of_match = socfpga_reset_match,
101 .probe = socfpga_reset_probe,
102 .priv_auto_alloc_size = sizeof(struct socfpga_reset_data),
103 .ops = &socfpga_reset_ops,
104 };
105