1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
4 * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
5 */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <reset-uclass.h>
11 #include <stm32_rcc.h>
12 #include <asm/io.h>
13
14 /* reset clear offset for STM32MP RCC */
15 #define RCC_CL 0x4
16
17 struct stm32_reset_priv {
18 fdt_addr_t base;
19 };
20
stm32_reset_request(struct reset_ctl * reset_ctl)21 static int stm32_reset_request(struct reset_ctl *reset_ctl)
22 {
23 return 0;
24 }
25
stm32_reset_free(struct reset_ctl * reset_ctl)26 static int stm32_reset_free(struct reset_ctl *reset_ctl)
27 {
28 return 0;
29 }
30
stm32_reset_assert(struct reset_ctl * reset_ctl)31 static int stm32_reset_assert(struct reset_ctl *reset_ctl)
32 {
33 struct stm32_reset_priv *priv = dev_get_priv(reset_ctl->dev);
34 int bank = (reset_ctl->id / BITS_PER_LONG) * 4;
35 int offset = reset_ctl->id % BITS_PER_LONG;
36 debug("%s: reset id = %ld bank = %d offset = %d)\n", __func__,
37 reset_ctl->id, bank, offset);
38
39 if (dev_get_driver_data(reset_ctl->dev) == STM32MP1)
40 /* reset assert is done in rcc set register */
41 writel(BIT(offset), priv->base + bank);
42 else
43 setbits_le32(priv->base + bank, BIT(offset));
44
45 return 0;
46 }
47
stm32_reset_deassert(struct reset_ctl * reset_ctl)48 static int stm32_reset_deassert(struct reset_ctl *reset_ctl)
49 {
50 struct stm32_reset_priv *priv = dev_get_priv(reset_ctl->dev);
51 int bank = (reset_ctl->id / BITS_PER_LONG) * 4;
52 int offset = reset_ctl->id % BITS_PER_LONG;
53 debug("%s: reset id = %ld bank = %d offset = %d)\n", __func__,
54 reset_ctl->id, bank, offset);
55
56 if (dev_get_driver_data(reset_ctl->dev) == STM32MP1)
57 /* reset deassert is done in rcc clr register */
58 writel(BIT(offset), priv->base + bank + RCC_CL);
59 else
60 clrbits_le32(priv->base + bank, BIT(offset));
61
62 return 0;
63 }
64
65 static const struct reset_ops stm32_reset_ops = {
66 .request = stm32_reset_request,
67 .free = stm32_reset_free,
68 .rst_assert = stm32_reset_assert,
69 .rst_deassert = stm32_reset_deassert,
70 };
71
stm32_reset_probe(struct udevice * dev)72 static int stm32_reset_probe(struct udevice *dev)
73 {
74 struct stm32_reset_priv *priv = dev_get_priv(dev);
75
76 priv->base = dev_read_addr(dev);
77 if (priv->base == FDT_ADDR_T_NONE) {
78 /* for MFD, get address of parent */
79 priv->base = dev_read_addr(dev->parent);
80 if (priv->base == FDT_ADDR_T_NONE)
81 return -EINVAL;
82 }
83
84 return 0;
85 }
86
87 U_BOOT_DRIVER(stm32_rcc_reset) = {
88 .name = "stm32_rcc_reset",
89 .id = UCLASS_RESET,
90 .probe = stm32_reset_probe,
91 .priv_auto_alloc_size = sizeof(struct stm32_reset_priv),
92 .ops = &stm32_reset_ops,
93 };
94