1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
4  * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
5  */
6 
7 #define LOG_CATEGORY UCLASS_RAM
8 
9 #include <common.h>
10 #include <clk.h>
11 #include <dm.h>
12 #include <init.h>
13 #include <log.h>
14 #include <ram.h>
15 #include <asm/io.h>
16 #include <dm/device_compat.h>
17 #include <linux/bitops.h>
18 #include <linux/delay.h>
19 
20 #define MEM_MODE_MASK	GENMASK(2, 0)
21 #define SWP_FMC_OFFSET 10
22 #define SWP_FMC_MASK	GENMASK(SWP_FMC_OFFSET+1, SWP_FMC_OFFSET)
23 #define NOT_FOUND	0xff
24 
25 struct stm32_fmc_regs {
26 	/* 0x0 */
27 	u32 bcr1;	/* NOR/PSRAM Chip select control register 1 */
28 	u32 btr1;	/* SRAM/NOR-Flash Chip select timing register 1 */
29 	u32 bcr2;	/* NOR/PSRAM Chip select Control register 2 */
30 	u32 btr2;	/* SRAM/NOR-Flash Chip select timing register 2 */
31 	u32 bcr3;	/* NOR/PSRAMChip select Control register 3 */
32 	u32 btr3;	/* SRAM/NOR-Flash Chip select timing register 3 */
33 	u32 bcr4;	/* NOR/PSRAM Chip select Control register 4 */
34 	u32 btr4;	/* SRAM/NOR-Flash Chip select timing register 4 */
35 	u32 reserved1[24];
36 
37 	/* 0x80 */
38 	u32 pcr;	/* NAND Flash control register */
39 	u32 sr;		/* FIFO status and interrupt register */
40 	u32 pmem;	/* Common memory space timing register */
41 	u32 patt;	/* Attribute memory space timing registers  */
42 	u32 reserved2[1];
43 	u32 eccr;	/* ECC result registers */
44 	u32 reserved3[27];
45 
46 	/* 0x104 */
47 	u32 bwtr1;	/* SRAM/NOR-Flash write timing register 1 */
48 	u32 reserved4[1];
49 	u32 bwtr2;	/* SRAM/NOR-Flash write timing register 2 */
50 	u32 reserved5[1];
51 	u32 bwtr3;	/* SRAM/NOR-Flash write timing register 3 */
52 	u32 reserved6[1];
53 	u32 bwtr4;	/* SRAM/NOR-Flash write timing register 4 */
54 	u32 reserved7[8];
55 
56 	/* 0x140 */
57 	u32 sdcr1;	/* SDRAM Control register 1 */
58 	u32 sdcr2;	/* SDRAM Control register 2 */
59 	u32 sdtr1;	/* SDRAM Timing register 1 */
60 	u32 sdtr2;	/* SDRAM Timing register 2 */
61 	u32 sdcmr;	/* SDRAM Mode register */
62 	u32 sdrtr;	/* SDRAM Refresh timing register */
63 	u32 sdsr;	/* SDRAM Status register */
64 };
65 
66 /*
67  * NOR/PSRAM Control register BCR1
68  * FMC controller Enable, only availabe for H7
69  */
70 #define FMC_BCR1_FMCEN		BIT(31)
71 
72 /* Control register SDCR */
73 #define FMC_SDCR_RPIPE_SHIFT	13	/* RPIPE bit shift */
74 #define FMC_SDCR_RBURST_SHIFT	12	/* RBURST bit shift */
75 #define FMC_SDCR_SDCLK_SHIFT	10	/* SDRAM clock divisor shift */
76 #define FMC_SDCR_WP_SHIFT	9	/* Write protection shift */
77 #define FMC_SDCR_CAS_SHIFT	7	/* CAS latency shift */
78 #define FMC_SDCR_NB_SHIFT	6	/* Number of banks shift */
79 #define FMC_SDCR_MWID_SHIFT	4	/* Memory width shift */
80 #define FMC_SDCR_NR_SHIFT	2	/* Number of row address bits shift */
81 #define FMC_SDCR_NC_SHIFT	0	/* Number of col address bits shift */
82 
83 /* Timings register SDTR */
84 #define FMC_SDTR_TMRD_SHIFT	0	/* Load mode register to active */
85 #define FMC_SDTR_TXSR_SHIFT	4	/* Exit self-refresh time */
86 #define FMC_SDTR_TRAS_SHIFT	8	/* Self-refresh time */
87 #define FMC_SDTR_TRC_SHIFT	12	/* Row cycle delay */
88 #define FMC_SDTR_TWR_SHIFT	16	/* Recovery delay */
89 #define FMC_SDTR_TRP_SHIFT	20	/* Row precharge delay */
90 #define FMC_SDTR_TRCD_SHIFT	24	/* Row-to-column delay */
91 
92 #define FMC_SDCMR_NRFS_SHIFT	5
93 
94 #define FMC_SDCMR_MODE_NORMAL		0
95 #define FMC_SDCMR_MODE_START_CLOCK	1
96 #define FMC_SDCMR_MODE_PRECHARGE	2
97 #define FMC_SDCMR_MODE_AUTOREFRESH	3
98 #define FMC_SDCMR_MODE_WRITE_MODE	4
99 #define FMC_SDCMR_MODE_SELFREFRESH	5
100 #define FMC_SDCMR_MODE_POWERDOWN	6
101 
102 #define FMC_SDCMR_BANK_1		BIT(4)
103 #define FMC_SDCMR_BANK_2		BIT(3)
104 
105 #define FMC_SDCMR_MODE_REGISTER_SHIFT	9
106 
107 #define FMC_SDSR_BUSY			BIT(5)
108 
109 #define FMC_BUSY_WAIT(regs)	do { \
110 		__asm__ __volatile__ ("dsb" : : : "memory"); \
111 		while (regs->sdsr & FMC_SDSR_BUSY) \
112 			; \
113 	} while (0)
114 
115 struct stm32_sdram_control {
116 	u8 no_columns;
117 	u8 no_rows;
118 	u8 memory_width;
119 	u8 no_banks;
120 	u8 cas_latency;
121 	u8 sdclk;
122 	u8 rd_burst;
123 	u8 rd_pipe_delay;
124 };
125 
126 struct stm32_sdram_timing {
127 	u8 tmrd;
128 	u8 txsr;
129 	u8 tras;
130 	u8 trc;
131 	u8 trp;
132 	u8 twr;
133 	u8 trcd;
134 };
135 enum stm32_fmc_bank {
136 	SDRAM_BANK1,
137 	SDRAM_BANK2,
138 	MAX_SDRAM_BANK,
139 };
140 
141 enum stm32_fmc_family {
142 	STM32F7_FMC,
143 	STM32H7_FMC,
144 };
145 
146 struct bank_params {
147 	struct stm32_sdram_control *sdram_control;
148 	struct stm32_sdram_timing *sdram_timing;
149 	u32 sdram_ref_count;
150 	enum stm32_fmc_bank target_bank;
151 };
152 
153 struct stm32_sdram_params {
154 	struct stm32_fmc_regs *base;
155 	u8 no_sdram_banks;
156 	struct bank_params bank_params[MAX_SDRAM_BANK];
157 	enum stm32_fmc_family family;
158 };
159 
160 #define SDRAM_MODE_BL_SHIFT	0
161 #define SDRAM_MODE_CAS_SHIFT	4
162 #define SDRAM_MODE_BL		0
163 
stm32_sdram_init(struct udevice * dev)164 int stm32_sdram_init(struct udevice *dev)
165 {
166 	struct stm32_sdram_params *params = dev_get_plat(dev);
167 	struct stm32_sdram_control *control;
168 	struct stm32_sdram_timing *timing;
169 	struct stm32_fmc_regs *regs = params->base;
170 	enum stm32_fmc_bank target_bank;
171 	u32 ctb; /* SDCMR register: Command Target Bank */
172 	u32 ref_count;
173 	u8 i;
174 
175 	/* disable the FMC controller */
176 	if (params->family == STM32H7_FMC)
177 		clrbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
178 
179 	for (i = 0; i < params->no_sdram_banks; i++) {
180 		control = params->bank_params[i].sdram_control;
181 		timing = params->bank_params[i].sdram_timing;
182 		target_bank = params->bank_params[i].target_bank;
183 		ref_count = params->bank_params[i].sdram_ref_count;
184 
185 		writel(control->sdclk << FMC_SDCR_SDCLK_SHIFT
186 			| control->cas_latency << FMC_SDCR_CAS_SHIFT
187 			| control->no_banks << FMC_SDCR_NB_SHIFT
188 			| control->memory_width << FMC_SDCR_MWID_SHIFT
189 			| control->no_rows << FMC_SDCR_NR_SHIFT
190 			| control->no_columns << FMC_SDCR_NC_SHIFT
191 			| control->rd_pipe_delay << FMC_SDCR_RPIPE_SHIFT
192 			| control->rd_burst << FMC_SDCR_RBURST_SHIFT,
193 			&regs->sdcr1);
194 
195 		if (target_bank == SDRAM_BANK2)
196 			writel(control->cas_latency << FMC_SDCR_CAS_SHIFT
197 				| control->no_banks << FMC_SDCR_NB_SHIFT
198 				| control->memory_width << FMC_SDCR_MWID_SHIFT
199 				| control->no_rows << FMC_SDCR_NR_SHIFT
200 				| control->no_columns << FMC_SDCR_NC_SHIFT,
201 				&regs->sdcr2);
202 
203 		writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
204 			| timing->trp << FMC_SDTR_TRP_SHIFT
205 			| timing->twr << FMC_SDTR_TWR_SHIFT
206 			| timing->trc << FMC_SDTR_TRC_SHIFT
207 			| timing->tras << FMC_SDTR_TRAS_SHIFT
208 			| timing->txsr << FMC_SDTR_TXSR_SHIFT
209 			| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
210 			&regs->sdtr1);
211 
212 		if (target_bank == SDRAM_BANK2)
213 			writel(timing->trcd << FMC_SDTR_TRCD_SHIFT
214 				| timing->trp << FMC_SDTR_TRP_SHIFT
215 				| timing->twr << FMC_SDTR_TWR_SHIFT
216 				| timing->trc << FMC_SDTR_TRC_SHIFT
217 				| timing->tras << FMC_SDTR_TRAS_SHIFT
218 				| timing->txsr << FMC_SDTR_TXSR_SHIFT
219 				| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
220 				&regs->sdtr2);
221 
222 		if (target_bank == SDRAM_BANK1)
223 			ctb = FMC_SDCMR_BANK_1;
224 		else
225 			ctb = FMC_SDCMR_BANK_2;
226 
227 		writel(ctb | FMC_SDCMR_MODE_START_CLOCK, &regs->sdcmr);
228 		udelay(200);	/* 200 us delay, page 10, "Power-Up" */
229 		FMC_BUSY_WAIT(regs);
230 
231 		writel(ctb | FMC_SDCMR_MODE_PRECHARGE, &regs->sdcmr);
232 		udelay(100);
233 		FMC_BUSY_WAIT(regs);
234 
235 		writel((ctb | FMC_SDCMR_MODE_AUTOREFRESH | 7 << FMC_SDCMR_NRFS_SHIFT),
236 		       &regs->sdcmr);
237 		udelay(100);
238 		FMC_BUSY_WAIT(regs);
239 
240 		writel(ctb | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
241 		       | control->cas_latency << SDRAM_MODE_CAS_SHIFT)
242 		       << FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE,
243 		       &regs->sdcmr);
244 		udelay(100);
245 		FMC_BUSY_WAIT(regs);
246 
247 		writel(ctb | FMC_SDCMR_MODE_NORMAL, &regs->sdcmr);
248 		FMC_BUSY_WAIT(regs);
249 
250 		/* Refresh timer */
251 		writel(ref_count << 1, &regs->sdrtr);
252 	}
253 
254 	/* enable the FMC controller */
255 	if (params->family == STM32H7_FMC)
256 		setbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
257 
258 	return 0;
259 }
260 
stm32_fmc_of_to_plat(struct udevice * dev)261 static int stm32_fmc_of_to_plat(struct udevice *dev)
262 {
263 	struct stm32_sdram_params *params = dev_get_plat(dev);
264 	struct bank_params *bank_params;
265 	struct ofnode_phandle_args args;
266 	u32 *syscfg_base;
267 	u32 mem_remap;
268 	u32 swp_fmc;
269 	ofnode bank_node;
270 	char *bank_name;
271 	u8 bank = 0;
272 	int ret;
273 
274 	ret = dev_read_phandle_with_args(dev, "st,syscfg", NULL, 0, 0,
275 						 &args);
276 	if (ret) {
277 		dev_dbg(dev, "can't find syscon device (%d)\n", ret);
278 	} else {
279 		syscfg_base = (u32 *)ofnode_get_addr(args.node);
280 
281 		mem_remap = dev_read_u32_default(dev, "st,mem_remap", NOT_FOUND);
282 		if (mem_remap != NOT_FOUND) {
283 			/* set memory mapping selection */
284 			clrsetbits_le32(syscfg_base, MEM_MODE_MASK, mem_remap);
285 		} else {
286 			dev_dbg(dev, "cannot find st,mem_remap property\n");
287 		}
288 
289 		swp_fmc = dev_read_u32_default(dev, "st,swp_fmc", NOT_FOUND);
290 		if (swp_fmc != NOT_FOUND) {
291 			/* set fmc swapping selection */
292 			clrsetbits_le32(syscfg_base, SWP_FMC_MASK, swp_fmc << SWP_FMC_OFFSET);
293 		} else {
294 			dev_dbg(dev, "cannot find st,swp_fmc property\n");
295 		}
296 
297 		dev_dbg(dev, "syscfg %x = %x\n", (u32)syscfg_base, *syscfg_base);
298 	}
299 
300 	dev_for_each_subnode(bank_node, dev) {
301 		/* extract the bank index from DT */
302 		bank_name = (char *)ofnode_get_name(bank_node);
303 		strsep(&bank_name, "@");
304 		if (!bank_name) {
305 			pr_err("missing sdram bank index");
306 			return -EINVAL;
307 		}
308 
309 		bank_params = &params->bank_params[bank];
310 		strict_strtoul(bank_name, 10,
311 			       (long unsigned int *)&bank_params->target_bank);
312 
313 		if (bank_params->target_bank >= MAX_SDRAM_BANK) {
314 			pr_err("Found bank %d , but only bank 0 and 1 are supported",
315 			      bank_params->target_bank);
316 			return -EINVAL;
317 		}
318 
319 		debug("Find bank %s %u\n", bank_name, bank_params->target_bank);
320 
321 		params->bank_params[bank].sdram_control =
322 			(struct stm32_sdram_control *)
323 			 ofnode_read_u8_array_ptr(bank_node,
324 						  "st,sdram-control",
325 						  sizeof(struct stm32_sdram_control));
326 
327 		if (!params->bank_params[bank].sdram_control) {
328 			pr_err("st,sdram-control not found for %s",
329 			      ofnode_get_name(bank_node));
330 			return -EINVAL;
331 		}
332 
333 
334 		params->bank_params[bank].sdram_timing =
335 			(struct stm32_sdram_timing *)
336 			 ofnode_read_u8_array_ptr(bank_node,
337 						  "st,sdram-timing",
338 						  sizeof(struct stm32_sdram_timing));
339 
340 		if (!params->bank_params[bank].sdram_timing) {
341 			pr_err("st,sdram-timing not found for %s",
342 			      ofnode_get_name(bank_node));
343 			return -EINVAL;
344 		}
345 
346 
347 		bank_params->sdram_ref_count = ofnode_read_u32_default(bank_node,
348 						"st,sdram-refcount", 8196);
349 		bank++;
350 	}
351 
352 	params->no_sdram_banks = bank;
353 	dev_dbg(dev, "no of banks = %d\n", params->no_sdram_banks);
354 
355 	return 0;
356 }
357 
stm32_fmc_probe(struct udevice * dev)358 static int stm32_fmc_probe(struct udevice *dev)
359 {
360 	struct stm32_sdram_params *params = dev_get_plat(dev);
361 	int ret;
362 	fdt_addr_t addr;
363 
364 	addr = dev_read_addr(dev);
365 	if (addr == FDT_ADDR_T_NONE)
366 		return -EINVAL;
367 
368 	params->base = (struct stm32_fmc_regs *)addr;
369 	params->family = dev_get_driver_data(dev);
370 
371 #ifdef CONFIG_CLK
372 	struct clk clk;
373 
374 	ret = clk_get_by_index(dev, 0, &clk);
375 	if (ret < 0)
376 		return ret;
377 
378 	ret = clk_enable(&clk);
379 
380 	if (ret) {
381 		dev_err(dev, "failed to enable clock\n");
382 		return ret;
383 	}
384 #endif
385 	ret = stm32_sdram_init(dev);
386 	if (ret)
387 		return ret;
388 
389 	return 0;
390 }
391 
stm32_fmc_get_info(struct udevice * dev,struct ram_info * info)392 static int stm32_fmc_get_info(struct udevice *dev, struct ram_info *info)
393 {
394 	return 0;
395 }
396 
397 static struct ram_ops stm32_fmc_ops = {
398 	.get_info = stm32_fmc_get_info,
399 };
400 
401 static const struct udevice_id stm32_fmc_ids[] = {
402 	{ .compatible = "st,stm32-fmc", .data = STM32F7_FMC },
403 	{ .compatible = "st,stm32h7-fmc", .data = STM32H7_FMC },
404 	{ }
405 };
406 
407 U_BOOT_DRIVER(stm32_fmc) = {
408 	.name = "stm32_fmc",
409 	.id = UCLASS_RAM,
410 	.of_match = stm32_fmc_ids,
411 	.ops = &stm32_fmc_ops,
412 	.of_to_plat = stm32_fmc_of_to_plat,
413 	.probe = stm32_fmc_probe,
414 	.plat_auto	= sizeof(struct stm32_sdram_params),
415 };
416