xref: /openbmc/u-boot/drivers/ram/stm32_sdram.c (revision baefb63a)
1 /*
2  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
3  * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <clk.h>
10 #include <dm.h>
11 #include <ram.h>
12 #include <asm/io.h>
13 
14 DECLARE_GLOBAL_DATA_PTR;
15 
16 struct stm32_fmc_regs {
17 	/* 0x0 */
18 	u32 bcr1;	/* NOR/PSRAM Chip select control register 1 */
19 	u32 btr1;	/* SRAM/NOR-Flash Chip select timing register 1 */
20 	u32 bcr2;	/* NOR/PSRAM Chip select Control register 2 */
21 	u32 btr2;	/* SRAM/NOR-Flash Chip select timing register 2 */
22 	u32 bcr3;	/* NOR/PSRAMChip select Control register 3 */
23 	u32 btr3;	/* SRAM/NOR-Flash Chip select timing register 3 */
24 	u32 bcr4;	/* NOR/PSRAM Chip select Control register 4 */
25 	u32 btr4;	/* SRAM/NOR-Flash Chip select timing register 4 */
26 	u32 reserved1[24];
27 
28 	/* 0x80 */
29 	u32 pcr;	/* NAND Flash control register */
30 	u32 sr;		/* FIFO status and interrupt register */
31 	u32 pmem;	/* Common memory space timing register */
32 	u32 patt;	/* Attribute memory space timing registers  */
33 	u32 reserved2[1];
34 	u32 eccr;	/* ECC result registers */
35 	u32 reserved3[27];
36 
37 	/* 0x104 */
38 	u32 bwtr1;	/* SRAM/NOR-Flash write timing register 1 */
39 	u32 reserved4[1];
40 	u32 bwtr2;	/* SRAM/NOR-Flash write timing register 2 */
41 	u32 reserved5[1];
42 	u32 bwtr3;	/* SRAM/NOR-Flash write timing register 3 */
43 	u32 reserved6[1];
44 	u32 bwtr4;	/* SRAM/NOR-Flash write timing register 4 */
45 	u32 reserved7[8];
46 
47 	/* 0x140 */
48 	u32 sdcr1;	/* SDRAM Control register 1 */
49 	u32 sdcr2;	/* SDRAM Control register 2 */
50 	u32 sdtr1;	/* SDRAM Timing register 1 */
51 	u32 sdtr2;	/* SDRAM Timing register 2 */
52 	u32 sdcmr;	/* SDRAM Mode register */
53 	u32 sdrtr;	/* SDRAM Refresh timing register */
54 	u32 sdsr;	/* SDRAM Status register */
55 };
56 
57 /*
58  * NOR/PSRAM Control register BCR1
59  * FMC controller Enable, only availabe for H7
60  */
61 #define FMC_BCR1_FMCEN		BIT(31)
62 
63 /* Control register SDCR */
64 #define FMC_SDCR_RPIPE_SHIFT	13	/* RPIPE bit shift */
65 #define FMC_SDCR_RBURST_SHIFT	12	/* RBURST bit shift */
66 #define FMC_SDCR_SDCLK_SHIFT	10	/* SDRAM clock divisor shift */
67 #define FMC_SDCR_WP_SHIFT	9	/* Write protection shift */
68 #define FMC_SDCR_CAS_SHIFT	7	/* CAS latency shift */
69 #define FMC_SDCR_NB_SHIFT	6	/* Number of banks shift */
70 #define FMC_SDCR_MWID_SHIFT	4	/* Memory width shift */
71 #define FMC_SDCR_NR_SHIFT	2	/* Number of row address bits shift */
72 #define FMC_SDCR_NC_SHIFT	0	/* Number of col address bits shift */
73 
74 /* Timings register SDTR */
75 #define FMC_SDTR_TMRD_SHIFT	0	/* Load mode register to active */
76 #define FMC_SDTR_TXSR_SHIFT	4	/* Exit self-refresh time */
77 #define FMC_SDTR_TRAS_SHIFT	8	/* Self-refresh time */
78 #define FMC_SDTR_TRC_SHIFT	12	/* Row cycle delay */
79 #define FMC_SDTR_TWR_SHIFT	16	/* Recovery delay */
80 #define FMC_SDTR_TRP_SHIFT	20	/* Row precharge delay */
81 #define FMC_SDTR_TRCD_SHIFT	24	/* Row-to-column delay */
82 
83 #define FMC_SDCMR_NRFS_SHIFT	5
84 
85 #define FMC_SDCMR_MODE_NORMAL		0
86 #define FMC_SDCMR_MODE_START_CLOCK	1
87 #define FMC_SDCMR_MODE_PRECHARGE	2
88 #define FMC_SDCMR_MODE_AUTOREFRESH	3
89 #define FMC_SDCMR_MODE_WRITE_MODE	4
90 #define FMC_SDCMR_MODE_SELFREFRESH	5
91 #define FMC_SDCMR_MODE_POWERDOWN	6
92 
93 #define FMC_SDCMR_BANK_1		BIT(4)
94 #define FMC_SDCMR_BANK_2		BIT(3)
95 
96 #define FMC_SDCMR_MODE_REGISTER_SHIFT	9
97 
98 #define FMC_SDSR_BUSY			BIT(5)
99 
100 #define FMC_BUSY_WAIT(regs)	do { \
101 		__asm__ __volatile__ ("dsb" : : : "memory"); \
102 		while (regs->sdsr & FMC_SDSR_BUSY) \
103 			; \
104 	} while (0)
105 
106 struct stm32_sdram_control {
107 	u8 no_columns;
108 	u8 no_rows;
109 	u8 memory_width;
110 	u8 no_banks;
111 	u8 cas_latency;
112 	u8 sdclk;
113 	u8 rd_burst;
114 	u8 rd_pipe_delay;
115 };
116 
117 struct stm32_sdram_timing {
118 	u8 tmrd;
119 	u8 txsr;
120 	u8 tras;
121 	u8 trc;
122 	u8 trp;
123 	u8 twr;
124 	u8 trcd;
125 };
126 enum stm32_fmc_bank {
127 	SDRAM_BANK1,
128 	SDRAM_BANK2,
129 	MAX_SDRAM_BANK,
130 };
131 
132 enum stm32_fmc_family {
133 	STM32F7_FMC,
134 	STM32H7_FMC,
135 };
136 
137 struct bank_params {
138 	struct stm32_sdram_control *sdram_control;
139 	struct stm32_sdram_timing *sdram_timing;
140 	u32 sdram_ref_count;
141 	enum stm32_fmc_bank target_bank;
142 };
143 
144 struct stm32_sdram_params {
145 	struct stm32_fmc_regs *base;
146 	u8 no_sdram_banks;
147 	struct bank_params bank_params[MAX_SDRAM_BANK];
148 	enum stm32_fmc_family family;
149 };
150 
151 #define SDRAM_MODE_BL_SHIFT	0
152 #define SDRAM_MODE_CAS_SHIFT	4
153 #define SDRAM_MODE_BL		0
154 
155 int stm32_sdram_init(struct udevice *dev)
156 {
157 	struct stm32_sdram_params *params = dev_get_platdata(dev);
158 	struct stm32_sdram_control *control;
159 	struct stm32_sdram_timing *timing;
160 	struct stm32_fmc_regs *regs = params->base;
161 	enum stm32_fmc_bank target_bank;
162 	u32 ctb; /* SDCMR register: Command Target Bank */
163 	u32 ref_count;
164 	u8 i;
165 
166 	/* disable the FMC controller */
167 	if (params->family == STM32H7_FMC)
168 		clrbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
169 
170 	for (i = 0; i < params->no_sdram_banks; i++) {
171 		control = params->bank_params[i].sdram_control;
172 		timing = params->bank_params[i].sdram_timing;
173 		target_bank = params->bank_params[i].target_bank;
174 		ref_count = params->bank_params[i].sdram_ref_count;
175 
176 		writel(control->sdclk << FMC_SDCR_SDCLK_SHIFT
177 			| control->cas_latency << FMC_SDCR_CAS_SHIFT
178 			| control->no_banks << FMC_SDCR_NB_SHIFT
179 			| control->memory_width << FMC_SDCR_MWID_SHIFT
180 			| control->no_rows << FMC_SDCR_NR_SHIFT
181 			| control->no_columns << FMC_SDCR_NC_SHIFT
182 			| control->rd_pipe_delay << FMC_SDCR_RPIPE_SHIFT
183 			| control->rd_burst << FMC_SDCR_RBURST_SHIFT,
184 			&regs->sdcr1);
185 
186 		if (target_bank == SDRAM_BANK2)
187 			writel(control->cas_latency << FMC_SDCR_CAS_SHIFT
188 				| control->no_banks << FMC_SDCR_NB_SHIFT
189 				| control->memory_width << FMC_SDCR_MWID_SHIFT
190 				| control->no_rows << FMC_SDCR_NR_SHIFT
191 				| control->no_columns << FMC_SDCR_NC_SHIFT,
192 				&regs->sdcr2);
193 
194 		writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
195 			| timing->trp << FMC_SDTR_TRP_SHIFT
196 			| timing->twr << FMC_SDTR_TWR_SHIFT
197 			| timing->trc << FMC_SDTR_TRC_SHIFT
198 			| timing->tras << FMC_SDTR_TRAS_SHIFT
199 			| timing->txsr << FMC_SDTR_TXSR_SHIFT
200 			| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
201 			&regs->sdtr1);
202 
203 		if (target_bank == SDRAM_BANK2)
204 			writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
205 				| timing->trp << FMC_SDTR_TRP_SHIFT
206 				| timing->twr << FMC_SDTR_TWR_SHIFT
207 				| timing->trc << FMC_SDTR_TRC_SHIFT
208 				| timing->tras << FMC_SDTR_TRAS_SHIFT
209 				| timing->txsr << FMC_SDTR_TXSR_SHIFT
210 				| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
211 				&regs->sdtr2);
212 
213 		if (target_bank == SDRAM_BANK1)
214 			ctb = FMC_SDCMR_BANK_1;
215 		else
216 			ctb = FMC_SDCMR_BANK_2;
217 
218 		writel(ctb | FMC_SDCMR_MODE_START_CLOCK, &regs->sdcmr);
219 		udelay(200);	/* 200 us delay, page 10, "Power-Up" */
220 		FMC_BUSY_WAIT(regs);
221 
222 		writel(ctb | FMC_SDCMR_MODE_PRECHARGE, &regs->sdcmr);
223 		udelay(100);
224 		FMC_BUSY_WAIT(regs);
225 
226 		writel((ctb | FMC_SDCMR_MODE_AUTOREFRESH | 7 << FMC_SDCMR_NRFS_SHIFT),
227 		       &regs->sdcmr);
228 		udelay(100);
229 		FMC_BUSY_WAIT(regs);
230 
231 		writel(ctb | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
232 		       | control->cas_latency << SDRAM_MODE_CAS_SHIFT)
233 		       << FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE,
234 		       &regs->sdcmr);
235 		udelay(100);
236 		FMC_BUSY_WAIT(regs);
237 
238 		writel(ctb | FMC_SDCMR_MODE_NORMAL, &regs->sdcmr);
239 		FMC_BUSY_WAIT(regs);
240 
241 		/* Refresh timer */
242 		writel(ref_count << 1, &regs->sdrtr);
243 	}
244 
245 	/* enable the FMC controller */
246 	if (params->family == STM32H7_FMC)
247 		setbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
248 
249 	return 0;
250 }
251 
252 static int stm32_fmc_ofdata_to_platdata(struct udevice *dev)
253 {
254 	struct stm32_sdram_params *params = dev_get_platdata(dev);
255 	struct bank_params *bank_params;
256 	ofnode bank_node;
257 	char *bank_name;
258 	u8 bank = 0;
259 
260 	dev_for_each_subnode(bank_node, dev) {
261 		/* extract the bank index from DT */
262 		bank_name = (char *)ofnode_get_name(bank_node);
263 		strsep(&bank_name, "@");
264 		if (!bank_name) {
265 			pr_err("missing sdram bank index");
266 			return -EINVAL;
267 		}
268 
269 		bank_params = &params->bank_params[bank];
270 		strict_strtoul(bank_name, 10,
271 			       (long unsigned int *)&bank_params->target_bank);
272 
273 		if (bank_params->target_bank >= MAX_SDRAM_BANK) {
274 			pr_err("Found bank %d , but only bank 0 and 1 are supported",
275 			      bank_params->target_bank);
276 			return -EINVAL;
277 		}
278 
279 		debug("Find bank %s %u\n", bank_name, bank_params->target_bank);
280 
281 		params->bank_params[bank].sdram_control =
282 			(struct stm32_sdram_control *)
283 			 ofnode_read_u8_array_ptr(bank_node,
284 						  "st,sdram-control",
285 						  sizeof(struct stm32_sdram_control));
286 
287 		if (!params->bank_params[bank].sdram_control) {
288 			pr_err("st,sdram-control not found for %s",
289 			      ofnode_get_name(bank_node));
290 			return -EINVAL;
291 		}
292 
293 
294 		params->bank_params[bank].sdram_timing =
295 			(struct stm32_sdram_timing *)
296 			 ofnode_read_u8_array_ptr(bank_node,
297 						  "st,sdram-timing",
298 						  sizeof(struct stm32_sdram_timing));
299 
300 		if (!params->bank_params[bank].sdram_timing) {
301 			pr_err("st,sdram-timing not found for %s",
302 			      ofnode_get_name(bank_node));
303 			return -EINVAL;
304 		}
305 
306 
307 		bank_params->sdram_ref_count = ofnode_read_u32_default(bank_node,
308 						"st,sdram-refcount", 8196);
309 		bank++;
310 	}
311 
312 	params->no_sdram_banks = bank;
313 	debug("%s, no of banks = %d\n", __func__, params->no_sdram_banks);
314 
315 	return 0;
316 }
317 
318 static int stm32_fmc_probe(struct udevice *dev)
319 {
320 	struct stm32_sdram_params *params = dev_get_platdata(dev);
321 	int ret;
322 	fdt_addr_t addr;
323 
324 	addr = dev_read_addr(dev);
325 	if (addr == FDT_ADDR_T_NONE)
326 		return -EINVAL;
327 
328 	params->base = (struct stm32_fmc_regs *)addr;
329 	params->family = dev_get_driver_data(dev);
330 
331 #ifdef CONFIG_CLK
332 	struct clk clk;
333 
334 	ret = clk_get_by_index(dev, 0, &clk);
335 	if (ret < 0)
336 		return ret;
337 
338 	ret = clk_enable(&clk);
339 
340 	if (ret) {
341 		dev_err(dev, "failed to enable clock\n");
342 		return ret;
343 	}
344 #endif
345 	ret = stm32_sdram_init(dev);
346 	if (ret)
347 		return ret;
348 
349 	return 0;
350 }
351 
352 static int stm32_fmc_get_info(struct udevice *dev, struct ram_info *info)
353 {
354 	return 0;
355 }
356 
357 static struct ram_ops stm32_fmc_ops = {
358 	.get_info = stm32_fmc_get_info,
359 };
360 
361 static const struct udevice_id stm32_fmc_ids[] = {
362 	{ .compatible = "st,stm32-fmc", .data = STM32F7_FMC },
363 	{ .compatible = "st,stm32h7-fmc", .data = STM32H7_FMC },
364 	{ }
365 };
366 
367 U_BOOT_DRIVER(stm32_fmc) = {
368 	.name = "stm32_fmc",
369 	.id = UCLASS_RAM,
370 	.of_match = stm32_fmc_ids,
371 	.ops = &stm32_fmc_ops,
372 	.ofdata_to_platdata = stm32_fmc_ofdata_to_platdata,
373 	.probe = stm32_fmc_probe,
374 	.platdata_auto_alloc_size = sizeof(struct stm32_sdram_params),
375 };
376