1 /*
2  * Copyright (c) 2019-2021, STMicroelectronics - All Rights Reserved
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <platform_def.h>
8 
9 #include <common/debug.h>
10 #include <drivers/st/bsec.h>
11 #include <drivers/st/stpmic1.h>
12 #include <lib/mmio.h>
13 
14 #include <stm32mp_dt.h>
15 #include <stm32mp1_private.h>
16 
17 /*
18  * SYSCFG REGISTER OFFSET (base relative)
19  */
20 #define SYSCFG_BOOTR				0x00U
21 #define SYSCFG_IOCTRLSETR			0x18U
22 #define SYSCFG_ICNR				0x1CU
23 #define SYSCFG_CMPCR				0x20U
24 #define SYSCFG_CMPENSETR			0x24U
25 #define SYSCFG_CMPENCLRR			0x28U
26 
27 /*
28  * SYSCFG_BOOTR Register
29  */
30 #define SYSCFG_BOOTR_BOOT_MASK			GENMASK(2, 0)
31 #define SYSCFG_BOOTR_BOOTPD_MASK		GENMASK(6, 4)
32 #define SYSCFG_BOOTR_BOOTPD_SHIFT		4
33 /*
34  * SYSCFG_IOCTRLSETR Register
35  */
36 #define SYSCFG_IOCTRLSETR_HSLVEN_TRACE		BIT(0)
37 #define SYSCFG_IOCTRLSETR_HSLVEN_QUADSPI	BIT(1)
38 #define SYSCFG_IOCTRLSETR_HSLVEN_ETH		BIT(2)
39 #define SYSCFG_IOCTRLSETR_HSLVEN_SDMMC		BIT(3)
40 #define SYSCFG_IOCTRLSETR_HSLVEN_SPI		BIT(4)
41 
42 /*
43  * SYSCFG_ICNR Register
44  */
45 #define SYSCFG_ICNR_AXI_M9			BIT(9)
46 
47 /*
48  * SYSCFG_CMPCR Register
49  */
50 #define SYSCFG_CMPCR_SW_CTRL			BIT(1)
51 #define SYSCFG_CMPCR_READY			BIT(8)
52 #define SYSCFG_CMPCR_RANSRC			GENMASK(19, 16)
53 #define SYSCFG_CMPCR_RANSRC_SHIFT		16
54 #define SYSCFG_CMPCR_RAPSRC			GENMASK(23, 20)
55 #define SYSCFG_CMPCR_ANSRC_SHIFT		24
56 
57 /*
58  * SYSCFG_CMPENSETR Register
59  */
60 #define SYSCFG_CMPENSETR_MPU_EN			BIT(0)
61 
stm32mp1_syscfg_init(void)62 void stm32mp1_syscfg_init(void)
63 {
64 	uint32_t bootr;
65 	uint32_t otp = 0;
66 	uint32_t vdd_voltage;
67 
68 	/*
69 	 * Interconnect update : select master using the port 1.
70 	 * LTDC = AXI_M9.
71 	 */
72 	mmio_write_32(SYSCFG_BASE + SYSCFG_ICNR, SYSCFG_ICNR_AXI_M9);
73 
74 	/* Disable Pull-Down for boot pin connected to VDD */
75 	bootr = mmio_read_32(SYSCFG_BASE + SYSCFG_BOOTR) &
76 		SYSCFG_BOOTR_BOOT_MASK;
77 	mmio_clrsetbits_32(SYSCFG_BASE + SYSCFG_BOOTR, SYSCFG_BOOTR_BOOTPD_MASK,
78 			   bootr << SYSCFG_BOOTR_BOOTPD_SHIFT);
79 
80 	/*
81 	 * High Speed Low Voltage Pad mode Enable for SPI, SDMMC, ETH, QSPI
82 	 * and TRACE. Needed above ~50MHz and conditioned by AFMUX selection.
83 	 * It could be disabled for low frequencies or if AFMUX is selected
84 	 * but the function is not used, typically for TRACE.
85 	 * If high speed low voltage pad mode is node enable, platform will
86 	 * over consume.
87 	 *
88 	 * WARNING:
89 	 *   Enabling High Speed mode while VDD > 2.7V
90 	 *   with the OTP product_below_2v5 (OTP 18, BIT 13)
91 	 *   erroneously set to 1 can damage the SoC!
92 	 *   => TF-A enables the low power mode only if VDD < 2.7V (in DT)
93 	 *      but this value needs to be consistent with board design.
94 	 */
95 	if (bsec_read_otp(&otp, HW2_OTP) != BSEC_OK) {
96 		panic();
97 	}
98 
99 	otp = otp & HW2_OTP_PRODUCT_BELOW_2V5;
100 
101 	/* Get VDD supply */
102 	vdd_voltage = dt_get_pwr_vdd_voltage();
103 
104 	/* Check if VDD is Low Voltage */
105 	if (vdd_voltage == 0U) {
106 		WARN("VDD unknown");
107 	} else if (vdd_voltage < 2700000U) {
108 		mmio_write_32(SYSCFG_BASE + SYSCFG_IOCTRLSETR,
109 			      SYSCFG_IOCTRLSETR_HSLVEN_TRACE |
110 			      SYSCFG_IOCTRLSETR_HSLVEN_QUADSPI |
111 			      SYSCFG_IOCTRLSETR_HSLVEN_ETH |
112 			      SYSCFG_IOCTRLSETR_HSLVEN_SDMMC |
113 			      SYSCFG_IOCTRLSETR_HSLVEN_SPI);
114 
115 		if (otp == 0U) {
116 			INFO("Product_below_2v5=0: HSLVEN protected by HW\n");
117 		}
118 	} else {
119 		if (otp != 0U) {
120 			ERROR("Product_below_2v5=1:\n");
121 			ERROR("\tHSLVEN update is destructive,\n");
122 			ERROR("\tno update as VDD > 2.7V\n");
123 			panic();
124 		}
125 	}
126 
127 	stm32mp1_syscfg_enable_io_compensation();
128 }
129 
stm32mp1_syscfg_enable_io_compensation(void)130 void stm32mp1_syscfg_enable_io_compensation(void)
131 {
132 	/*
133 	 * Activate automatic I/O compensation.
134 	 * Warning: need to ensure CSI enabled and ready in clock driver.
135 	 * Enable non-secure clock, we assume non-secure is suspended.
136 	 */
137 	stm32mp1_clk_enable_non_secure(SYSCFG);
138 
139 	mmio_setbits_32(SYSCFG_BASE + SYSCFG_CMPENSETR,
140 			SYSCFG_CMPENSETR_MPU_EN);
141 
142 	while ((mmio_read_32(SYSCFG_BASE + SYSCFG_CMPCR) &
143 		SYSCFG_CMPCR_READY) == 0U) {
144 		;
145 	}
146 
147 	mmio_clrbits_32(SYSCFG_BASE + SYSCFG_CMPCR, SYSCFG_CMPCR_SW_CTRL);
148 }
149 
stm32mp1_syscfg_disable_io_compensation(void)150 void stm32mp1_syscfg_disable_io_compensation(void)
151 {
152 	uint32_t value;
153 
154 	/*
155 	 * Deactivate automatic I/O compensation.
156 	 * Warning: CSI is disabled automatically in STOP if not
157 	 * requested for other usages and always OFF in STANDBY.
158 	 * Disable non-secure SYSCFG clock, we assume non-secure is suspended.
159 	 */
160 	value = mmio_read_32(SYSCFG_BASE + SYSCFG_CMPCR) >>
161 	      SYSCFG_CMPCR_ANSRC_SHIFT;
162 
163 	mmio_clrbits_32(SYSCFG_BASE + SYSCFG_CMPCR,
164 			SYSCFG_CMPCR_RANSRC | SYSCFG_CMPCR_RAPSRC);
165 
166 	value = mmio_read_32(SYSCFG_BASE + SYSCFG_CMPCR) |
167 		(value << SYSCFG_CMPCR_RANSRC_SHIFT);
168 
169 	mmio_write_32(SYSCFG_BASE + SYSCFG_CMPCR, value | SYSCFG_CMPCR_SW_CTRL);
170 
171 	mmio_setbits_32(SYSCFG_BASE + SYSCFG_CMPENCLRR, SYSCFG_CMPENSETR_MPU_EN);
172 
173 	stm32mp1_clk_disable_non_secure(SYSCFG);
174 }
175