xref: /openbmc/u-boot/drivers/ram/stm32_sdram.c (revision d024236e5a31a2b4b82cbcc98b31b8170fc88d28)
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 #define MEM_MODE_MASK	GENMASK(2, 0)
15 #define NOT_FOUND	0xff
16 
17 struct stm32_fmc_regs {
18 	/* 0x0 */
19 	u32 bcr1;	/* NOR/PSRAM Chip select control register 1 */
20 	u32 btr1;	/* SRAM/NOR-Flash Chip select timing register 1 */
21 	u32 bcr2;	/* NOR/PSRAM Chip select Control register 2 */
22 	u32 btr2;	/* SRAM/NOR-Flash Chip select timing register 2 */
23 	u32 bcr3;	/* NOR/PSRAMChip select Control register 3 */
24 	u32 btr3;	/* SRAM/NOR-Flash Chip select timing register 3 */
25 	u32 bcr4;	/* NOR/PSRAM Chip select Control register 4 */
26 	u32 btr4;	/* SRAM/NOR-Flash Chip select timing register 4 */
27 	u32 reserved1[24];
28 
29 	/* 0x80 */
30 	u32 pcr;	/* NAND Flash control register */
31 	u32 sr;		/* FIFO status and interrupt register */
32 	u32 pmem;	/* Common memory space timing register */
33 	u32 patt;	/* Attribute memory space timing registers  */
34 	u32 reserved2[1];
35 	u32 eccr;	/* ECC result registers */
36 	u32 reserved3[27];
37 
38 	/* 0x104 */
39 	u32 bwtr1;	/* SRAM/NOR-Flash write timing register 1 */
40 	u32 reserved4[1];
41 	u32 bwtr2;	/* SRAM/NOR-Flash write timing register 2 */
42 	u32 reserved5[1];
43 	u32 bwtr3;	/* SRAM/NOR-Flash write timing register 3 */
44 	u32 reserved6[1];
45 	u32 bwtr4;	/* SRAM/NOR-Flash write timing register 4 */
46 	u32 reserved7[8];
47 
48 	/* 0x140 */
49 	u32 sdcr1;	/* SDRAM Control register 1 */
50 	u32 sdcr2;	/* SDRAM Control register 2 */
51 	u32 sdtr1;	/* SDRAM Timing register 1 */
52 	u32 sdtr2;	/* SDRAM Timing register 2 */
53 	u32 sdcmr;	/* SDRAM Mode register */
54 	u32 sdrtr;	/* SDRAM Refresh timing register */
55 	u32 sdsr;	/* SDRAM Status register */
56 };
57 
58 /*
59  * NOR/PSRAM Control register BCR1
60  * FMC controller Enable, only availabe for H7
61  */
62 #define FMC_BCR1_FMCEN		BIT(31)
63 
64 /* Control register SDCR */
65 #define FMC_SDCR_RPIPE_SHIFT	13	/* RPIPE bit shift */
66 #define FMC_SDCR_RBURST_SHIFT	12	/* RBURST bit shift */
67 #define FMC_SDCR_SDCLK_SHIFT	10	/* SDRAM clock divisor shift */
68 #define FMC_SDCR_WP_SHIFT	9	/* Write protection shift */
69 #define FMC_SDCR_CAS_SHIFT	7	/* CAS latency shift */
70 #define FMC_SDCR_NB_SHIFT	6	/* Number of banks shift */
71 #define FMC_SDCR_MWID_SHIFT	4	/* Memory width shift */
72 #define FMC_SDCR_NR_SHIFT	2	/* Number of row address bits shift */
73 #define FMC_SDCR_NC_SHIFT	0	/* Number of col address bits shift */
74 
75 /* Timings register SDTR */
76 #define FMC_SDTR_TMRD_SHIFT	0	/* Load mode register to active */
77 #define FMC_SDTR_TXSR_SHIFT	4	/* Exit self-refresh time */
78 #define FMC_SDTR_TRAS_SHIFT	8	/* Self-refresh time */
79 #define FMC_SDTR_TRC_SHIFT	12	/* Row cycle delay */
80 #define FMC_SDTR_TWR_SHIFT	16	/* Recovery delay */
81 #define FMC_SDTR_TRP_SHIFT	20	/* Row precharge delay */
82 #define FMC_SDTR_TRCD_SHIFT	24	/* Row-to-column delay */
83 
84 #define FMC_SDCMR_NRFS_SHIFT	5
85 
86 #define FMC_SDCMR_MODE_NORMAL		0
87 #define FMC_SDCMR_MODE_START_CLOCK	1
88 #define FMC_SDCMR_MODE_PRECHARGE	2
89 #define FMC_SDCMR_MODE_AUTOREFRESH	3
90 #define FMC_SDCMR_MODE_WRITE_MODE	4
91 #define FMC_SDCMR_MODE_SELFREFRESH	5
92 #define FMC_SDCMR_MODE_POWERDOWN	6
93 
94 #define FMC_SDCMR_BANK_1		BIT(4)
95 #define FMC_SDCMR_BANK_2		BIT(3)
96 
97 #define FMC_SDCMR_MODE_REGISTER_SHIFT	9
98 
99 #define FMC_SDSR_BUSY			BIT(5)
100 
101 #define FMC_BUSY_WAIT(regs)	do { \
102 		__asm__ __volatile__ ("dsb" : : : "memory"); \
103 		while (regs->sdsr & FMC_SDSR_BUSY) \
104 			; \
105 	} while (0)
106 
107 struct stm32_sdram_control {
108 	u8 no_columns;
109 	u8 no_rows;
110 	u8 memory_width;
111 	u8 no_banks;
112 	u8 cas_latency;
113 	u8 sdclk;
114 	u8 rd_burst;
115 	u8 rd_pipe_delay;
116 };
117 
118 struct stm32_sdram_timing {
119 	u8 tmrd;
120 	u8 txsr;
121 	u8 tras;
122 	u8 trc;
123 	u8 trp;
124 	u8 twr;
125 	u8 trcd;
126 };
127 enum stm32_fmc_bank {
128 	SDRAM_BANK1,
129 	SDRAM_BANK2,
130 	MAX_SDRAM_BANK,
131 };
132 
133 enum stm32_fmc_family {
134 	STM32F7_FMC,
135 	STM32H7_FMC,
136 };
137 
138 struct bank_params {
139 	struct stm32_sdram_control *sdram_control;
140 	struct stm32_sdram_timing *sdram_timing;
141 	u32 sdram_ref_count;
142 	enum stm32_fmc_bank target_bank;
143 };
144 
145 struct stm32_sdram_params {
146 	struct stm32_fmc_regs *base;
147 	u8 no_sdram_banks;
148 	struct bank_params bank_params[MAX_SDRAM_BANK];
149 	enum stm32_fmc_family family;
150 };
151 
152 #define SDRAM_MODE_BL_SHIFT	0
153 #define SDRAM_MODE_CAS_SHIFT	4
154 #define SDRAM_MODE_BL		0
155 
156 int stm32_sdram_init(struct udevice *dev)
157 {
158 	struct stm32_sdram_params *params = dev_get_platdata(dev);
159 	struct stm32_sdram_control *control;
160 	struct stm32_sdram_timing *timing;
161 	struct stm32_fmc_regs *regs = params->base;
162 	enum stm32_fmc_bank target_bank;
163 	u32 ctb; /* SDCMR register: Command Target Bank */
164 	u32 ref_count;
165 	u8 i;
166 
167 	/* disable the FMC controller */
168 	if (params->family == STM32H7_FMC)
169 		clrbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
170 
171 	for (i = 0; i < params->no_sdram_banks; i++) {
172 		control = params->bank_params[i].sdram_control;
173 		timing = params->bank_params[i].sdram_timing;
174 		target_bank = params->bank_params[i].target_bank;
175 		ref_count = params->bank_params[i].sdram_ref_count;
176 
177 		writel(control->sdclk << FMC_SDCR_SDCLK_SHIFT
178 			| control->cas_latency << FMC_SDCR_CAS_SHIFT
179 			| control->no_banks << FMC_SDCR_NB_SHIFT
180 			| control->memory_width << FMC_SDCR_MWID_SHIFT
181 			| control->no_rows << FMC_SDCR_NR_SHIFT
182 			| control->no_columns << FMC_SDCR_NC_SHIFT
183 			| control->rd_pipe_delay << FMC_SDCR_RPIPE_SHIFT
184 			| control->rd_burst << FMC_SDCR_RBURST_SHIFT,
185 			&regs->sdcr1);
186 
187 		if (target_bank == SDRAM_BANK2)
188 			writel(control->cas_latency << FMC_SDCR_CAS_SHIFT
189 				| control->no_banks << FMC_SDCR_NB_SHIFT
190 				| control->memory_width << FMC_SDCR_MWID_SHIFT
191 				| control->no_rows << FMC_SDCR_NR_SHIFT
192 				| control->no_columns << FMC_SDCR_NC_SHIFT,
193 				&regs->sdcr2);
194 
195 		writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
196 			| timing->trp << FMC_SDTR_TRP_SHIFT
197 			| timing->twr << FMC_SDTR_TWR_SHIFT
198 			| timing->trc << FMC_SDTR_TRC_SHIFT
199 			| timing->tras << FMC_SDTR_TRAS_SHIFT
200 			| timing->txsr << FMC_SDTR_TXSR_SHIFT
201 			| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
202 			&regs->sdtr1);
203 
204 		if (target_bank == SDRAM_BANK2)
205 			writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
206 				| timing->trp << FMC_SDTR_TRP_SHIFT
207 				| timing->twr << FMC_SDTR_TWR_SHIFT
208 				| timing->trc << FMC_SDTR_TRC_SHIFT
209 				| timing->tras << FMC_SDTR_TRAS_SHIFT
210 				| timing->txsr << FMC_SDTR_TXSR_SHIFT
211 				| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
212 				&regs->sdtr2);
213 
214 		if (target_bank == SDRAM_BANK1)
215 			ctb = FMC_SDCMR_BANK_1;
216 		else
217 			ctb = FMC_SDCMR_BANK_2;
218 
219 		writel(ctb | FMC_SDCMR_MODE_START_CLOCK, &regs->sdcmr);
220 		udelay(200);	/* 200 us delay, page 10, "Power-Up" */
221 		FMC_BUSY_WAIT(regs);
222 
223 		writel(ctb | FMC_SDCMR_MODE_PRECHARGE, &regs->sdcmr);
224 		udelay(100);
225 		FMC_BUSY_WAIT(regs);
226 
227 		writel((ctb | FMC_SDCMR_MODE_AUTOREFRESH | 7 << FMC_SDCMR_NRFS_SHIFT),
228 		       &regs->sdcmr);
229 		udelay(100);
230 		FMC_BUSY_WAIT(regs);
231 
232 		writel(ctb | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
233 		       | control->cas_latency << SDRAM_MODE_CAS_SHIFT)
234 		       << FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE,
235 		       &regs->sdcmr);
236 		udelay(100);
237 		FMC_BUSY_WAIT(regs);
238 
239 		writel(ctb | FMC_SDCMR_MODE_NORMAL, &regs->sdcmr);
240 		FMC_BUSY_WAIT(regs);
241 
242 		/* Refresh timer */
243 		writel(ref_count << 1, &regs->sdrtr);
244 	}
245 
246 	/* enable the FMC controller */
247 	if (params->family == STM32H7_FMC)
248 		setbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
249 
250 	return 0;
251 }
252 
253 static int stm32_fmc_ofdata_to_platdata(struct udevice *dev)
254 {
255 	struct stm32_sdram_params *params = dev_get_platdata(dev);
256 	struct bank_params *bank_params;
257 	struct ofnode_phandle_args args;
258 	u32 *syscfg_base;
259 	u32 mem_remap;
260 	ofnode bank_node;
261 	char *bank_name;
262 	u8 bank = 0;
263 	int ret;
264 
265 	mem_remap = dev_read_u32_default(dev, "st,mem_remap", NOT_FOUND);
266 	if (mem_remap != NOT_FOUND) {
267 		ret = dev_read_phandle_with_args(dev, "st,syscfg", NULL, 0, 0,
268 						 &args);
269 		if (ret) {
270 			debug("%s: can't find syscon device (%d)\n", __func__,
271 			      ret);
272 			return ret;
273 		}
274 
275 		syscfg_base = (u32 *)ofnode_get_addr(args.node);
276 
277 		/* set memory mapping selection */
278 		clrsetbits_le32(syscfg_base, MEM_MODE_MASK, mem_remap);
279 	} else {
280 		debug("%s: cannot find st,mem_remap property\n", __func__);
281 	}
282 
283 	dev_for_each_subnode(bank_node, dev) {
284 		/* extract the bank index from DT */
285 		bank_name = (char *)ofnode_get_name(bank_node);
286 		strsep(&bank_name, "@");
287 		if (!bank_name) {
288 			pr_err("missing sdram bank index");
289 			return -EINVAL;
290 		}
291 
292 		bank_params = &params->bank_params[bank];
293 		strict_strtoul(bank_name, 10,
294 			       (long unsigned int *)&bank_params->target_bank);
295 
296 		if (bank_params->target_bank >= MAX_SDRAM_BANK) {
297 			pr_err("Found bank %d , but only bank 0 and 1 are supported",
298 			      bank_params->target_bank);
299 			return -EINVAL;
300 		}
301 
302 		debug("Find bank %s %u\n", bank_name, bank_params->target_bank);
303 
304 		params->bank_params[bank].sdram_control =
305 			(struct stm32_sdram_control *)
306 			 ofnode_read_u8_array_ptr(bank_node,
307 						  "st,sdram-control",
308 						  sizeof(struct stm32_sdram_control));
309 
310 		if (!params->bank_params[bank].sdram_control) {
311 			pr_err("st,sdram-control not found for %s",
312 			      ofnode_get_name(bank_node));
313 			return -EINVAL;
314 		}
315 
316 
317 		params->bank_params[bank].sdram_timing =
318 			(struct stm32_sdram_timing *)
319 			 ofnode_read_u8_array_ptr(bank_node,
320 						  "st,sdram-timing",
321 						  sizeof(struct stm32_sdram_timing));
322 
323 		if (!params->bank_params[bank].sdram_timing) {
324 			pr_err("st,sdram-timing not found for %s",
325 			      ofnode_get_name(bank_node));
326 			return -EINVAL;
327 		}
328 
329 
330 		bank_params->sdram_ref_count = ofnode_read_u32_default(bank_node,
331 						"st,sdram-refcount", 8196);
332 		bank++;
333 	}
334 
335 	params->no_sdram_banks = bank;
336 	debug("%s, no of banks = %d\n", __func__, params->no_sdram_banks);
337 
338 	return 0;
339 }
340 
341 static int stm32_fmc_probe(struct udevice *dev)
342 {
343 	struct stm32_sdram_params *params = dev_get_platdata(dev);
344 	int ret;
345 	fdt_addr_t addr;
346 
347 	addr = dev_read_addr(dev);
348 	if (addr == FDT_ADDR_T_NONE)
349 		return -EINVAL;
350 
351 	params->base = (struct stm32_fmc_regs *)addr;
352 	params->family = dev_get_driver_data(dev);
353 
354 #ifdef CONFIG_CLK
355 	struct clk clk;
356 
357 	ret = clk_get_by_index(dev, 0, &clk);
358 	if (ret < 0)
359 		return ret;
360 
361 	ret = clk_enable(&clk);
362 
363 	if (ret) {
364 		dev_err(dev, "failed to enable clock\n");
365 		return ret;
366 	}
367 #endif
368 	ret = stm32_sdram_init(dev);
369 	if (ret)
370 		return ret;
371 
372 	return 0;
373 }
374 
375 static int stm32_fmc_get_info(struct udevice *dev, struct ram_info *info)
376 {
377 	return 0;
378 }
379 
380 static struct ram_ops stm32_fmc_ops = {
381 	.get_info = stm32_fmc_get_info,
382 };
383 
384 static const struct udevice_id stm32_fmc_ids[] = {
385 	{ .compatible = "st,stm32-fmc", .data = STM32F7_FMC },
386 	{ .compatible = "st,stm32h7-fmc", .data = STM32H7_FMC },
387 	{ }
388 };
389 
390 U_BOOT_DRIVER(stm32_fmc) = {
391 	.name = "stm32_fmc",
392 	.id = UCLASS_RAM,
393 	.of_match = stm32_fmc_ids,
394 	.ops = &stm32_fmc_ops,
395 	.ofdata_to_platdata = stm32_fmc_ofdata_to_platdata,
396 	.probe = stm32_fmc_probe,
397 	.platdata_auto_alloc_size = sizeof(struct stm32_sdram_params),
398 };
399