1 /*
2  * Copyright (c) 2017-2020, STMicroelectronics - All Rights Reserved
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <errno.h>
9 #include <stdint.h>
10 
11 #include <arch_helpers.h>
12 #include <common/debug.h>
13 #include <drivers/st/etzpc.h>
14 #include <dt-bindings/soc/st,stm32-etzpc.h>
15 #include <lib/mmio.h>
16 #include <lib/utils_def.h>
17 #include <libfdt.h>
18 
19 #include <platform_def.h>
20 
21 /* Device Tree related definitions */
22 #define ETZPC_COMPAT			"st,stm32-etzpc"
23 #define ETZPC_LOCK_MASK			0x1U
24 #define ETZPC_MODE_SHIFT		8
25 #define ETZPC_MODE_MASK			GENMASK(1, 0)
26 #define ETZPC_ID_SHIFT			16
27 #define ETZPC_ID_MASK			GENMASK(7, 0)
28 
29 /* ID Registers */
30 #define ETZPC_TZMA0_SIZE		0x000U
31 #define ETZPC_DECPROT0			0x010U
32 #define ETZPC_DECPROT_LOCK0		0x030U
33 #define ETZPC_HWCFGR			0x3F0U
34 #define ETZPC_VERR			0x3F4U
35 
36 /* ID Registers fields */
37 #define ETZPC_TZMA0_SIZE_LOCK		BIT(31)
38 #define ETZPC_DECPROT0_MASK		GENMASK(1, 0)
39 #define ETZPC_HWCFGR_NUM_TZMA_SHIFT	0
40 #define ETZPC_HWCFGR_NUM_PER_SEC_SHIFT	8
41 #define ETZPC_HWCFGR_NUM_AHB_SEC_SHIFT	16
42 #define ETZPC_HWCFGR_CHUNCKS1N4_SHIFT	24
43 
44 #define DECPROT_SHIFT			1
45 #define IDS_PER_DECPROT_REGS		16U
46 #define IDS_PER_DECPROT_LOCK_REGS	32U
47 
48 /*
49  * etzpc_instance.
50  * base : register base address set during init given by user
51  * chunk_size : supported TZMA size steps
52  * num_tzma: number of TZMA zone read from register at init
53  * num_ahb_sec : number of securable AHB master zone read from register
54  * num_per_sec : number of securable AHB & APB Peripherals read from register
55  * revision : IP revision read from register at init
56  */
57 struct etzpc_instance {
58 	uintptr_t base;
59 	uint8_t chunck_size;
60 	uint8_t num_tzma;
61 	uint8_t num_per_sec;
62 	uint8_t num_ahb_sec;
63 	uint8_t revision;
64 };
65 
66 /* Only 1 instance of the ETZPC is expected per platform */
67 static struct etzpc_instance etzpc_dev;
68 
69 /*
70  * Implementation uses uint8_t to store each securable DECPROT configuration.
71  * When resuming from deep suspend, the DECPROT configurations are restored.
72  */
73 #define PERIPH_LOCK_BIT		BIT(7)
74 #define PERIPH_ATTR_MASK	GENMASK(2, 0)
75 
76 #if ENABLE_ASSERTIONS
valid_decprot_id(unsigned int id)77 static bool valid_decprot_id(unsigned int id)
78 {
79 	return id < (unsigned int)etzpc_dev.num_per_sec;
80 }
81 
valid_tzma_id(unsigned int id)82 static bool valid_tzma_id(unsigned int id)
83 {
84 	return id < (unsigned int)etzpc_dev.num_tzma;
85 }
86 #endif
87 
88 /*
89  * etzpc_configure_decprot : Load a DECPROT configuration
90  * decprot_id : ID of the IP
91  * decprot_attr : Restriction access attribute
92  */
etzpc_configure_decprot(uint32_t decprot_id,enum etzpc_decprot_attributes decprot_attr)93 void etzpc_configure_decprot(uint32_t decprot_id,
94 			     enum etzpc_decprot_attributes decprot_attr)
95 {
96 	uintptr_t offset = 4U * (decprot_id / IDS_PER_DECPROT_REGS);
97 	uint32_t shift = (decprot_id % IDS_PER_DECPROT_REGS) << DECPROT_SHIFT;
98 	uint32_t masked_decprot = (uint32_t)decprot_attr & ETZPC_DECPROT0_MASK;
99 
100 	assert(valid_decprot_id(decprot_id));
101 
102 	mmio_clrsetbits_32(etzpc_dev.base + ETZPC_DECPROT0 + offset,
103 			   (uint32_t)ETZPC_DECPROT0_MASK << shift,
104 			   masked_decprot << shift);
105 }
106 
107 /*
108  * etzpc_get_decprot : Get the DECPROT attribute
109  * decprot_id : ID of the IP
110  * return : Attribute of this DECPROT
111  */
etzpc_get_decprot(uint32_t decprot_id)112 enum etzpc_decprot_attributes etzpc_get_decprot(uint32_t decprot_id)
113 {
114 	uintptr_t offset = 4U * (decprot_id / IDS_PER_DECPROT_REGS);
115 	uint32_t shift = (decprot_id % IDS_PER_DECPROT_REGS) << DECPROT_SHIFT;
116 	uintptr_t base_decprot = etzpc_dev.base + offset;
117 	uint32_t value;
118 
119 	assert(valid_decprot_id(decprot_id));
120 
121 	value = (mmio_read_32(base_decprot + ETZPC_DECPROT0) >> shift) &
122 		ETZPC_DECPROT0_MASK;
123 
124 	return (enum etzpc_decprot_attributes)value;
125 }
126 
127 /*
128  * etzpc_lock_decprot : Lock access to the DECPROT attribute
129  * decprot_id : ID of the IP
130  */
etzpc_lock_decprot(uint32_t decprot_id)131 void etzpc_lock_decprot(uint32_t decprot_id)
132 {
133 	uintptr_t offset = 4U * (decprot_id / IDS_PER_DECPROT_LOCK_REGS);
134 	uint32_t shift = BIT(decprot_id % IDS_PER_DECPROT_LOCK_REGS);
135 	uintptr_t base_decprot = etzpc_dev.base + offset;
136 
137 	assert(valid_decprot_id(decprot_id));
138 
139 	mmio_write_32(base_decprot + ETZPC_DECPROT_LOCK0, shift);
140 }
141 
142 /*
143  * etzpc_configure_tzma : Configure the target TZMA read only size
144  * tzma_id : ID of the memory
145  * tzma_value : read-only size
146  */
etzpc_configure_tzma(uint32_t tzma_id,uint16_t tzma_value)147 void etzpc_configure_tzma(uint32_t tzma_id, uint16_t tzma_value)
148 {
149 	assert(valid_tzma_id(tzma_id));
150 
151 	mmio_write_32(etzpc_dev.base + ETZPC_TZMA0_SIZE +
152 		      (sizeof(uint32_t) * tzma_id), tzma_value);
153 }
154 
155 /*
156  * etzpc_get_tzma : Get the target TZMA read only size
157  * tzma_id : TZMA ID
158  * return : Size of read only size
159  */
etzpc_get_tzma(uint32_t tzma_id)160 uint16_t etzpc_get_tzma(uint32_t tzma_id)
161 {
162 	assert(valid_tzma_id(tzma_id));
163 
164 	return (uint16_t)mmio_read_32(etzpc_dev.base + ETZPC_TZMA0_SIZE +
165 				      (sizeof(uint32_t) * tzma_id));
166 }
167 
168 /*
169  * etzpc_lock_tzma : Lock the target TZMA
170  * tzma_id : TZMA ID
171  */
etzpc_lock_tzma(uint32_t tzma_id)172 void etzpc_lock_tzma(uint32_t tzma_id)
173 {
174 	assert(valid_tzma_id(tzma_id));
175 
176 	mmio_setbits_32(etzpc_dev.base + ETZPC_TZMA0_SIZE +
177 			(sizeof(uint32_t) * tzma_id), ETZPC_TZMA0_SIZE_LOCK);
178 }
179 
180 /*
181  * etzpc_get_lock_tzma : Return the lock status of the target TZMA
182  * tzma_id : TZMA ID
183  * return : True if TZMA is locked, false otherwise
184  */
etzpc_get_lock_tzma(uint32_t tzma_id)185 bool etzpc_get_lock_tzma(uint32_t tzma_id)
186 {
187 	uint32_t tzma_size;
188 
189 	assert(valid_tzma_id(tzma_id));
190 
191 	tzma_size = mmio_read_32(etzpc_dev.base + ETZPC_TZMA0_SIZE +
192 				 (sizeof(uint32_t) * tzma_id));
193 
194 	return (tzma_size & ETZPC_TZMA0_SIZE_LOCK) != 0;
195 }
196 
197 /*
198  * etzpc_get_num_per_sec : Return the DECPROT ID limit value
199  */
etzpc_get_num_per_sec(void)200 uint8_t etzpc_get_num_per_sec(void)
201 {
202 	return etzpc_dev.num_per_sec;
203 }
204 
205 /*
206  * etzpc_get_revision : Return the ETZPC IP revision
207  */
etzpc_get_revision(void)208 uint8_t etzpc_get_revision(void)
209 {
210 	return etzpc_dev.revision;
211 }
212 
213 /*
214  * etzpc_get_base_address : Return the ETZPC IP base address
215  */
etzpc_get_base_address(void)216 uintptr_t etzpc_get_base_address(void)
217 {
218 	return etzpc_dev.base;
219 }
220 
221 /*
222  * etzpc_init : Initialize the ETZPC driver
223  * Return 0 on success and a negative errno on failure
224  */
etzpc_init(void)225 int etzpc_init(void)
226 {
227 	uint32_t hwcfg;
228 	int node;
229 	struct dt_node_info etzpc_info;
230 
231 	node = dt_get_node(&etzpc_info, -1, ETZPC_COMPAT);
232 	if (node < 0) {
233 		return -EIO;
234 	}
235 
236 	/* Check ETZPC is secure only */
237 	if (etzpc_info.status != DT_SECURE) {
238 		return -EACCES;
239 	}
240 
241 	etzpc_dev.base = etzpc_info.base;
242 
243 	hwcfg = mmio_read_32(etzpc_dev.base + ETZPC_HWCFGR);
244 
245 	etzpc_dev.num_tzma = (uint8_t)(hwcfg >> ETZPC_HWCFGR_NUM_TZMA_SHIFT);
246 	etzpc_dev.num_per_sec = (uint8_t)(hwcfg >>
247 					  ETZPC_HWCFGR_NUM_PER_SEC_SHIFT);
248 	etzpc_dev.num_ahb_sec = (uint8_t)(hwcfg >>
249 					  ETZPC_HWCFGR_NUM_AHB_SEC_SHIFT);
250 	etzpc_dev.chunck_size = (uint8_t)(hwcfg >>
251 					  ETZPC_HWCFGR_CHUNCKS1N4_SHIFT);
252 
253 	etzpc_dev.revision = mmio_read_8(etzpc_dev.base + ETZPC_VERR);
254 
255 	VERBOSE("ETZPC version 0x%x", etzpc_dev.revision);
256 
257 	return 0;
258 }
259