1 /*
2  * Copyright (C) 2018-2020, STMicroelectronics - All Rights Reserved
3  *
4  * SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
5  */
6 
7 #include <errno.h>
8 
9 #include <libfdt.h>
10 
11 #include <platform_def.h>
12 
13 #include <arch_helpers.h>
14 #include <common/debug.h>
15 #include <common/fdt_wrappers.h>
16 #include <drivers/st/stm32mp1_ddr.h>
17 #include <drivers/st/stm32mp1_ddr_helpers.h>
18 #include <drivers/st/stm32mp1_ram.h>
19 #include <lib/mmio.h>
20 
21 #define DDR_PATTERN	0xAAAAAAAAU
22 #define DDR_ANTIPATTERN	0x55555555U
23 
24 static struct ddr_info ddr_priv_data;
25 
stm32mp1_ddr_clk_enable(struct ddr_info * priv,uint32_t mem_speed)26 int stm32mp1_ddr_clk_enable(struct ddr_info *priv, uint32_t mem_speed)
27 {
28 	unsigned long ddrphy_clk, ddr_clk, mem_speed_hz;
29 
30 	ddr_enable_clock();
31 
32 	ddrphy_clk = stm32mp_clk_get_rate(DDRPHYC);
33 
34 	VERBOSE("DDR: mem_speed (%d kHz), RCC %ld kHz\n",
35 		mem_speed, ddrphy_clk / 1000U);
36 
37 	mem_speed_hz = mem_speed * 1000U;
38 
39 	/* Max 10% frequency delta */
40 	if (ddrphy_clk > mem_speed_hz) {
41 		ddr_clk = ddrphy_clk - mem_speed_hz;
42 	} else {
43 		ddr_clk = mem_speed_hz - ddrphy_clk;
44 	}
45 	if (ddr_clk > (mem_speed_hz / 10)) {
46 		ERROR("DDR expected freq %d kHz, current is %ld kHz\n",
47 		      mem_speed, ddrphy_clk / 1000U);
48 		return -1;
49 	}
50 	return 0;
51 }
52 
53 /*******************************************************************************
54  * This function tests the DDR data bus wiring.
55  * This is inspired from the Data Bus Test algorithm written by Michael Barr
56  * in "Programming Embedded Systems in C and C++" book.
57  * resources.oreilly.com/examples/9781565923546/blob/master/Chapter6/
58  * File: memtest.c - This source code belongs to Public Domain.
59  * Returns 0 if success, and address value else.
60  ******************************************************************************/
ddr_test_data_bus(void)61 static uint32_t ddr_test_data_bus(void)
62 {
63 	uint32_t pattern;
64 
65 	for (pattern = 1U; pattern != 0U; pattern <<= 1) {
66 		mmio_write_32(STM32MP_DDR_BASE, pattern);
67 
68 		if (mmio_read_32(STM32MP_DDR_BASE) != pattern) {
69 			return (uint32_t)STM32MP_DDR_BASE;
70 		}
71 	}
72 
73 	return 0;
74 }
75 
76 /*******************************************************************************
77  * This function tests the DDR address bus wiring.
78  * This is inspired from the Data Bus Test algorithm written by Michael Barr
79  * in "Programming Embedded Systems in C and C++" book.
80  * resources.oreilly.com/examples/9781565923546/blob/master/Chapter6/
81  * File: memtest.c - This source code belongs to Public Domain.
82  * Returns 0 if success, and address value else.
83  ******************************************************************************/
ddr_test_addr_bus(void)84 static uint32_t ddr_test_addr_bus(void)
85 {
86 	uint64_t addressmask = (ddr_priv_data.info.size - 1U);
87 	uint64_t offset;
88 	uint64_t testoffset = 0;
89 
90 	/* Write the default pattern at each of the power-of-two offsets. */
91 	for (offset = sizeof(uint32_t); (offset & addressmask) != 0U;
92 	     offset <<= 1) {
93 		mmio_write_32(STM32MP_DDR_BASE + (uint32_t)offset,
94 			      DDR_PATTERN);
95 	}
96 
97 	/* Check for address bits stuck high. */
98 	mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset,
99 		      DDR_ANTIPATTERN);
100 
101 	for (offset = sizeof(uint32_t); (offset & addressmask) != 0U;
102 	     offset <<= 1) {
103 		if (mmio_read_32(STM32MP_DDR_BASE + (uint32_t)offset) !=
104 		    DDR_PATTERN) {
105 			return (uint32_t)(STM32MP_DDR_BASE + offset);
106 		}
107 	}
108 
109 	mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset, DDR_PATTERN);
110 
111 	/* Check for address bits stuck low or shorted. */
112 	for (testoffset = sizeof(uint32_t); (testoffset & addressmask) != 0U;
113 	     testoffset <<= 1) {
114 		mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset,
115 			      DDR_ANTIPATTERN);
116 
117 		if (mmio_read_32(STM32MP_DDR_BASE) != DDR_PATTERN) {
118 			return STM32MP_DDR_BASE;
119 		}
120 
121 		for (offset = sizeof(uint32_t); (offset & addressmask) != 0U;
122 		     offset <<= 1) {
123 			if ((mmio_read_32(STM32MP_DDR_BASE +
124 					  (uint32_t)offset) != DDR_PATTERN) &&
125 			    (offset != testoffset)) {
126 				return (uint32_t)(STM32MP_DDR_BASE + offset);
127 			}
128 		}
129 
130 		mmio_write_32(STM32MP_DDR_BASE + (uint32_t)testoffset,
131 			      DDR_PATTERN);
132 	}
133 
134 	return 0;
135 }
136 
137 /*******************************************************************************
138  * This function checks the DDR size. It has to be run with Data Cache off.
139  * This test is run before data have been put in DDR, and is only done for
140  * cold boot. The DDR data can then be overwritten, and it is not useful to
141  * restore its content.
142  * Returns DDR computed size.
143  ******************************************************************************/
ddr_check_size(void)144 static uint32_t ddr_check_size(void)
145 {
146 	uint32_t offset = sizeof(uint32_t);
147 
148 	mmio_write_32(STM32MP_DDR_BASE, DDR_PATTERN);
149 
150 	while (offset < STM32MP_DDR_MAX_SIZE) {
151 		mmio_write_32(STM32MP_DDR_BASE + offset, DDR_ANTIPATTERN);
152 		dsb();
153 
154 		if (mmio_read_32(STM32MP_DDR_BASE) != DDR_PATTERN) {
155 			break;
156 		}
157 
158 		offset <<= 1;
159 	}
160 
161 	INFO("Memory size = 0x%x (%d MB)\n", offset, offset / (1024U * 1024U));
162 
163 	return offset;
164 }
165 
stm32mp1_ddr_setup(void)166 static int stm32mp1_ddr_setup(void)
167 {
168 	struct ddr_info *priv = &ddr_priv_data;
169 	int ret;
170 	struct stm32mp1_ddr_config config;
171 	int node, len;
172 	uint32_t uret, idx;
173 	void *fdt;
174 
175 #define PARAM(x, y)							\
176 	{								\
177 		.name = x,						\
178 		.offset = offsetof(struct stm32mp1_ddr_config, y),	\
179 		.size = sizeof(config.y) / sizeof(uint32_t)		\
180 	}
181 
182 #define CTL_PARAM(x) PARAM("st,ctl-"#x, c_##x)
183 #define PHY_PARAM(x) PARAM("st,phy-"#x, p_##x)
184 
185 	const struct {
186 		const char *name; /* Name in DT */
187 		const uint32_t offset; /* Offset in config struct */
188 		const uint32_t size;   /* Size of parameters */
189 	} param[] = {
190 		CTL_PARAM(reg),
191 		CTL_PARAM(timing),
192 		CTL_PARAM(map),
193 		CTL_PARAM(perf),
194 		PHY_PARAM(reg),
195 		PHY_PARAM(timing),
196 		PHY_PARAM(cal)
197 	};
198 
199 	if (fdt_get_address(&fdt) == 0) {
200 		return -ENOENT;
201 	}
202 
203 	node = fdt_node_offset_by_compatible(fdt, -1, DT_DDR_COMPAT);
204 	if (node < 0) {
205 		ERROR("%s: Cannot read DDR node in DT\n", __func__);
206 		return -EINVAL;
207 	}
208 
209 	ret = fdt_read_uint32(fdt, node, "st,mem-speed", &config.info.speed);
210 	if (ret < 0) {
211 		VERBOSE("%s: no st,mem-speed\n", __func__);
212 		return -EINVAL;
213 	}
214 	ret = fdt_read_uint32(fdt, node, "st,mem-size", &config.info.size);
215 	if (ret < 0) {
216 		VERBOSE("%s: no st,mem-size\n", __func__);
217 		return -EINVAL;
218 	}
219 	config.info.name = fdt_getprop(fdt, node, "st,mem-name", &len);
220 	if (config.info.name == NULL) {
221 		VERBOSE("%s: no st,mem-name\n", __func__);
222 		return -EINVAL;
223 	}
224 	INFO("RAM: %s\n", config.info.name);
225 
226 	for (idx = 0; idx < ARRAY_SIZE(param); idx++) {
227 		ret = fdt_read_uint32_array(fdt, node, param[idx].name,
228 					    param[idx].size,
229 					    (void *)((uintptr_t)&config +
230 						     param[idx].offset));
231 
232 		VERBOSE("%s: %s[0x%x] = %d\n", __func__,
233 			param[idx].name, param[idx].size, ret);
234 		if (ret != 0) {
235 			ERROR("%s: Cannot read %s\n",
236 			      __func__, param[idx].name);
237 			return -EINVAL;
238 		}
239 	}
240 
241 	/* Disable axidcg clock gating during init */
242 	mmio_clrbits_32(priv->rcc + RCC_DDRITFCR, RCC_DDRITFCR_AXIDCGEN);
243 
244 	stm32mp1_ddr_init(priv, &config);
245 
246 	/* Enable axidcg clock gating */
247 	mmio_setbits_32(priv->rcc + RCC_DDRITFCR, RCC_DDRITFCR_AXIDCGEN);
248 
249 	priv->info.size = config.info.size;
250 
251 	VERBOSE("%s : ram size(%x, %x)\n", __func__,
252 		(uint32_t)priv->info.base, (uint32_t)priv->info.size);
253 
254 	if (stm32mp_map_ddr_non_cacheable() != 0) {
255 		panic();
256 	}
257 
258 	uret = ddr_test_data_bus();
259 	if (uret != 0U) {
260 		ERROR("DDR data bus test: can't access memory @ 0x%x\n",
261 		      uret);
262 		panic();
263 	}
264 
265 	uret = ddr_test_addr_bus();
266 	if (uret != 0U) {
267 		ERROR("DDR addr bus test: can't access memory @ 0x%x\n",
268 		      uret);
269 		panic();
270 	}
271 
272 	uret = ddr_check_size();
273 	if (uret < config.info.size) {
274 		ERROR("DDR size: 0x%x does not match DT config: 0x%x\n",
275 		      uret, config.info.size);
276 		panic();
277 	}
278 
279 	if (stm32mp_unmap_ddr() != 0) {
280 		panic();
281 	}
282 
283 	return 0;
284 }
285 
stm32mp1_ddr_probe(void)286 int stm32mp1_ddr_probe(void)
287 {
288 	struct ddr_info *priv = &ddr_priv_data;
289 
290 	VERBOSE("STM32MP DDR probe\n");
291 
292 	priv->ctl = (struct stm32mp1_ddrctl *)stm32mp_ddrctrl_base();
293 	priv->phy = (struct stm32mp1_ddrphy *)stm32mp_ddrphyc_base();
294 	priv->pwr = stm32mp_pwr_base();
295 	priv->rcc = stm32mp_rcc_base();
296 
297 	priv->info.base = STM32MP_DDR_BASE;
298 	priv->info.size = 0;
299 
300 	return stm32mp1_ddr_setup();
301 }
302