xref: /rk3399_ARM-atf/drivers/st/reset/stm32mp2_reset.c (revision f829d7df7e261fb8f68e21dbceab8c77ce65aedd)
1*f829d7dfSGabriel Fernandez /*
2*f829d7dfSGabriel Fernandez  * Copyright (c) 2024, STMicroelectronics - All Rights Reserved
3*f829d7dfSGabriel Fernandez  *
4*f829d7dfSGabriel Fernandez  * SPDX-License-Identifier: BSD-3-Clause
5*f829d7dfSGabriel Fernandez  */
6*f829d7dfSGabriel Fernandez 
7*f829d7dfSGabriel Fernandez #include <errno.h>
8*f829d7dfSGabriel Fernandez #include <stdbool.h>
9*f829d7dfSGabriel Fernandez 
10*f829d7dfSGabriel Fernandez #include <common/debug.h>
11*f829d7dfSGabriel Fernandez #include <drivers/delay_timer.h>
12*f829d7dfSGabriel Fernandez #include <drivers/st/stm32mp_reset.h>
13*f829d7dfSGabriel Fernandez #include <lib/mmio.h>
14*f829d7dfSGabriel Fernandez #include <lib/utils_def.h>
15*f829d7dfSGabriel Fernandez 
16*f829d7dfSGabriel Fernandez #include <platform_def.h>
17*f829d7dfSGabriel Fernandez 
18*f829d7dfSGabriel Fernandez static uint32_t id2reg_offset(unsigned int reset_id)
19*f829d7dfSGabriel Fernandez {
20*f829d7dfSGabriel Fernandez 	return ((reset_id & GENMASK(31, 5)) >> 5) * sizeof(uint32_t);
21*f829d7dfSGabriel Fernandez }
22*f829d7dfSGabriel Fernandez 
23*f829d7dfSGabriel Fernandez static uint8_t id2reg_bit_pos(unsigned int reset_id)
24*f829d7dfSGabriel Fernandez {
25*f829d7dfSGabriel Fernandez 	return (uint8_t)(reset_id & GENMASK(4, 0));
26*f829d7dfSGabriel Fernandez }
27*f829d7dfSGabriel Fernandez 
28*f829d7dfSGabriel Fernandez static int reset_toggle(uint32_t id, unsigned int to_us, bool reset_status)
29*f829d7dfSGabriel Fernandez {
30*f829d7dfSGabriel Fernandez 	uint32_t offset = id2reg_offset(id);
31*f829d7dfSGabriel Fernandez 	uint32_t bitmsk = BIT(id2reg_bit_pos(id));
32*f829d7dfSGabriel Fernandez 	uint32_t bit_check;
33*f829d7dfSGabriel Fernandez 	uintptr_t rcc_base = stm32mp_rcc_base();
34*f829d7dfSGabriel Fernandez 
35*f829d7dfSGabriel Fernandez 	if (reset_status) {
36*f829d7dfSGabriel Fernandez 		mmio_setbits_32(rcc_base + offset, bitmsk);
37*f829d7dfSGabriel Fernandez 		bit_check = bitmsk;
38*f829d7dfSGabriel Fernandez 	} else {
39*f829d7dfSGabriel Fernandez 		mmio_clrbits_32(rcc_base + offset, bitmsk);
40*f829d7dfSGabriel Fernandez 		bit_check = 0U;
41*f829d7dfSGabriel Fernandez 	}
42*f829d7dfSGabriel Fernandez 
43*f829d7dfSGabriel Fernandez 	if (to_us != 0U) {
44*f829d7dfSGabriel Fernandez 		uint64_t timeout_ref = timeout_init_us(to_us);
45*f829d7dfSGabriel Fernandez 
46*f829d7dfSGabriel Fernandez 		while ((mmio_read_32(rcc_base + offset) & bitmsk) != bit_check) {
47*f829d7dfSGabriel Fernandez 			if (timeout_elapsed(timeout_ref)) {
48*f829d7dfSGabriel Fernandez 				return -ETIMEDOUT;
49*f829d7dfSGabriel Fernandez 			}
50*f829d7dfSGabriel Fernandez 		}
51*f829d7dfSGabriel Fernandez 	}
52*f829d7dfSGabriel Fernandez 
53*f829d7dfSGabriel Fernandez 	return 0;
54*f829d7dfSGabriel Fernandez }
55*f829d7dfSGabriel Fernandez 
56*f829d7dfSGabriel Fernandez int stm32mp_reset_assert(uint32_t id, unsigned int to_us)
57*f829d7dfSGabriel Fernandez {
58*f829d7dfSGabriel Fernandez 	return reset_toggle(id, to_us, true);
59*f829d7dfSGabriel Fernandez }
60*f829d7dfSGabriel Fernandez 
61*f829d7dfSGabriel Fernandez int stm32mp_reset_deassert(uint32_t id, unsigned int to_us)
62*f829d7dfSGabriel Fernandez {
63*f829d7dfSGabriel Fernandez 	return reset_toggle(id, to_us, false);
64*f829d7dfSGabriel Fernandez }
65*f829d7dfSGabriel Fernandez 
66*f829d7dfSGabriel Fernandez void __dead2 stm32mp_system_reset(void)
67*f829d7dfSGabriel Fernandez {
68*f829d7dfSGabriel Fernandez 	uintptr_t rcc_base = stm32mp_rcc_base();
69*f829d7dfSGabriel Fernandez 
70*f829d7dfSGabriel Fernandez 	mmio_setbits_32(rcc_base + RCC_GRSTCSETR, RCC_GRSTCSETR_SYSRST);
71*f829d7dfSGabriel Fernandez 
72*f829d7dfSGabriel Fernandez 	/* Loop in case system reset is not immediately caught */
73*f829d7dfSGabriel Fernandez 	while (true) {
74*f829d7dfSGabriel Fernandez 		wfi();
75*f829d7dfSGabriel Fernandez 	}
76*f829d7dfSGabriel Fernandez }
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