1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * LPDDR2-NVM MTD driver. This module provides read, write, erase, lock/unlock
4 * support for LPDDR2-NVM PCM memories
5 *
6 * Copyright © 2012 Micron Technology, Inc.
7 *
8 * Vincenzo Aliberti <vincenzo.aliberti@gmail.com>
9 * Domenico Manna <domenico.manna@gmail.com>
10 * Many thanks to Andrea Vigilante for initial enabling
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
14
15 #include <linux/init.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/mtd/map.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/partitions.h>
22 #include <linux/slab.h>
23 #include <linux/platform_device.h>
24 #include <linux/ioport.h>
25 #include <linux/err.h>
26
27 /* Parameters */
28 #define ERASE_BLOCKSIZE (0x00020000/2) /* in Word */
29 #define WRITE_BUFFSIZE (0x00000400/2) /* in Word */
30 #define OW_BASE_ADDRESS 0x00000000 /* OW offset */
31 #define BUS_WIDTH 0x00000020 /* x32 devices */
32
33 /* PFOW symbols address offset */
34 #define PFOW_QUERY_STRING_P (0x0000/2) /* in Word */
35 #define PFOW_QUERY_STRING_F (0x0002/2) /* in Word */
36 #define PFOW_QUERY_STRING_O (0x0004/2) /* in Word */
37 #define PFOW_QUERY_STRING_W (0x0006/2) /* in Word */
38
39 /* OW registers address */
40 #define CMD_CODE_OFS (0x0080/2) /* in Word */
41 #define CMD_DATA_OFS (0x0084/2) /* in Word */
42 #define CMD_ADD_L_OFS (0x0088/2) /* in Word */
43 #define CMD_ADD_H_OFS (0x008A/2) /* in Word */
44 #define MPR_L_OFS (0x0090/2) /* in Word */
45 #define MPR_H_OFS (0x0092/2) /* in Word */
46 #define CMD_EXEC_OFS (0x00C0/2) /* in Word */
47 #define STATUS_REG_OFS (0x00CC/2) /* in Word */
48 #define PRG_BUFFER_OFS (0x0010/2) /* in Word */
49
50 /* Datamask */
51 #define MR_CFGMASK 0x8000
52 #define SR_OK_DATAMASK 0x0080
53
54 /* LPDDR2-NVM Commands */
55 #define LPDDR2_NVM_LOCK 0x0061
56 #define LPDDR2_NVM_UNLOCK 0x0062
57 #define LPDDR2_NVM_SW_PROGRAM 0x0041
58 #define LPDDR2_NVM_SW_OVERWRITE 0x0042
59 #define LPDDR2_NVM_BUF_PROGRAM 0x00E9
60 #define LPDDR2_NVM_BUF_OVERWRITE 0x00EA
61 #define LPDDR2_NVM_ERASE 0x0020
62
63 /* LPDDR2-NVM Registers offset */
64 #define LPDDR2_MODE_REG_DATA 0x0040
65 #define LPDDR2_MODE_REG_CFG 0x0050
66
67 /*
68 * Internal Type Definitions
69 * pcm_int_data contains memory controller details:
70 * @reg_data : LPDDR2_MODE_REG_DATA register address after remapping
71 * @reg_cfg : LPDDR2_MODE_REG_CFG register address after remapping
72 * &bus_width: memory bus-width (eg: x16 2 Bytes, x32 4 Bytes)
73 */
74 struct pcm_int_data {
75 void __iomem *ctl_regs;
76 int bus_width;
77 };
78
79 static DEFINE_MUTEX(lpdd2_nvm_mutex);
80
81 /*
82 * Build a map_word starting from an u_long
83 */
build_map_word(u_long myword)84 static inline map_word build_map_word(u_long myword)
85 {
86 map_word val = { {0} };
87 val.x[0] = myword;
88 return val;
89 }
90
91 /*
92 * Build Mode Register Configuration DataMask based on device bus-width
93 */
build_mr_cfgmask(u_int bus_width)94 static inline u_int build_mr_cfgmask(u_int bus_width)
95 {
96 u_int val = MR_CFGMASK;
97
98 if (bus_width == 0x0004) /* x32 device */
99 val = val << 16;
100
101 return val;
102 }
103
104 /*
105 * Build Status Register OK DataMask based on device bus-width
106 */
build_sr_ok_datamask(u_int bus_width)107 static inline u_int build_sr_ok_datamask(u_int bus_width)
108 {
109 u_int val = SR_OK_DATAMASK;
110
111 if (bus_width == 0x0004) /* x32 device */
112 val = (val << 16)+val;
113
114 return val;
115 }
116
117 /*
118 * Evaluates Overlay Window Control Registers address
119 */
ow_reg_add(struct map_info * map,u_long offset)120 static inline u_long ow_reg_add(struct map_info *map, u_long offset)
121 {
122 u_long val = 0;
123 struct pcm_int_data *pcm_data = map->fldrv_priv;
124
125 val = map->pfow_base + offset*pcm_data->bus_width;
126
127 return val;
128 }
129
130 /*
131 * Enable lpddr2-nvm Overlay Window
132 * Overlay Window is a memory mapped area containing all LPDDR2-NVM registers
133 * used by device commands as well as uservisible resources like Device Status
134 * Register, Device ID, etc
135 */
ow_enable(struct map_info * map)136 static inline void ow_enable(struct map_info *map)
137 {
138 struct pcm_int_data *pcm_data = map->fldrv_priv;
139
140 writel_relaxed(build_mr_cfgmask(pcm_data->bus_width) | 0x18,
141 pcm_data->ctl_regs + LPDDR2_MODE_REG_CFG);
142 writel_relaxed(0x01, pcm_data->ctl_regs + LPDDR2_MODE_REG_DATA);
143 }
144
145 /*
146 * Disable lpddr2-nvm Overlay Window
147 * Overlay Window is a memory mapped area containing all LPDDR2-NVM registers
148 * used by device commands as well as uservisible resources like Device Status
149 * Register, Device ID, etc
150 */
ow_disable(struct map_info * map)151 static inline void ow_disable(struct map_info *map)
152 {
153 struct pcm_int_data *pcm_data = map->fldrv_priv;
154
155 writel_relaxed(build_mr_cfgmask(pcm_data->bus_width) | 0x18,
156 pcm_data->ctl_regs + LPDDR2_MODE_REG_CFG);
157 writel_relaxed(0x02, pcm_data->ctl_regs + LPDDR2_MODE_REG_DATA);
158 }
159
160 /*
161 * Execute lpddr2-nvm operations
162 */
lpddr2_nvm_do_op(struct map_info * map,u_long cmd_code,u_long cmd_data,u_long cmd_add,u_long cmd_mpr,u_char * buf)163 static int lpddr2_nvm_do_op(struct map_info *map, u_long cmd_code,
164 u_long cmd_data, u_long cmd_add, u_long cmd_mpr, u_char *buf)
165 {
166 map_word add_l = { {0} }, add_h = { {0} }, mpr_l = { {0} },
167 mpr_h = { {0} }, data_l = { {0} }, cmd = { {0} },
168 exec_cmd = { {0} }, sr;
169 map_word data_h = { {0} }; /* only for 2x x16 devices stacked */
170 u_long i, status_reg, prg_buff_ofs;
171 struct pcm_int_data *pcm_data = map->fldrv_priv;
172 u_int sr_ok_datamask = build_sr_ok_datamask(pcm_data->bus_width);
173
174 /* Builds low and high words for OW Control Registers */
175 add_l.x[0] = cmd_add & 0x0000FFFF;
176 add_h.x[0] = (cmd_add >> 16) & 0x0000FFFF;
177 mpr_l.x[0] = cmd_mpr & 0x0000FFFF;
178 mpr_h.x[0] = (cmd_mpr >> 16) & 0x0000FFFF;
179 cmd.x[0] = cmd_code & 0x0000FFFF;
180 exec_cmd.x[0] = 0x0001;
181 data_l.x[0] = cmd_data & 0x0000FFFF;
182 data_h.x[0] = (cmd_data >> 16) & 0x0000FFFF; /* only for 2x x16 */
183
184 /* Set Overlay Window Control Registers */
185 map_write(map, cmd, ow_reg_add(map, CMD_CODE_OFS));
186 map_write(map, data_l, ow_reg_add(map, CMD_DATA_OFS));
187 map_write(map, add_l, ow_reg_add(map, CMD_ADD_L_OFS));
188 map_write(map, add_h, ow_reg_add(map, CMD_ADD_H_OFS));
189 map_write(map, mpr_l, ow_reg_add(map, MPR_L_OFS));
190 map_write(map, mpr_h, ow_reg_add(map, MPR_H_OFS));
191 if (pcm_data->bus_width == 0x0004) { /* 2x16 devices stacked */
192 map_write(map, cmd, ow_reg_add(map, CMD_CODE_OFS) + 2);
193 map_write(map, data_h, ow_reg_add(map, CMD_DATA_OFS) + 2);
194 map_write(map, add_l, ow_reg_add(map, CMD_ADD_L_OFS) + 2);
195 map_write(map, add_h, ow_reg_add(map, CMD_ADD_H_OFS) + 2);
196 map_write(map, mpr_l, ow_reg_add(map, MPR_L_OFS) + 2);
197 map_write(map, mpr_h, ow_reg_add(map, MPR_H_OFS) + 2);
198 }
199
200 /* Fill Program Buffer */
201 if ((cmd_code == LPDDR2_NVM_BUF_PROGRAM) ||
202 (cmd_code == LPDDR2_NVM_BUF_OVERWRITE)) {
203 prg_buff_ofs = (map_read(map,
204 ow_reg_add(map, PRG_BUFFER_OFS))).x[0];
205 for (i = 0; i < cmd_mpr; i++) {
206 map_write(map, build_map_word(buf[i]), map->pfow_base +
207 prg_buff_ofs + i);
208 }
209 }
210
211 /* Command Execute */
212 map_write(map, exec_cmd, ow_reg_add(map, CMD_EXEC_OFS));
213 if (pcm_data->bus_width == 0x0004) /* 2x16 devices stacked */
214 map_write(map, exec_cmd, ow_reg_add(map, CMD_EXEC_OFS) + 2);
215
216 /* Status Register Check */
217 do {
218 sr = map_read(map, ow_reg_add(map, STATUS_REG_OFS));
219 status_reg = sr.x[0];
220 if (pcm_data->bus_width == 0x0004) {/* 2x16 devices stacked */
221 sr = map_read(map, ow_reg_add(map,
222 STATUS_REG_OFS) + 2);
223 status_reg += sr.x[0] << 16;
224 }
225 } while ((status_reg & sr_ok_datamask) != sr_ok_datamask);
226
227 return (((status_reg & sr_ok_datamask) == sr_ok_datamask) ? 0 : -EIO);
228 }
229
230 /*
231 * Execute lpddr2-nvm operations @ block level
232 */
lpddr2_nvm_do_block_op(struct mtd_info * mtd,loff_t start_add,uint64_t len,u_char block_op)233 static int lpddr2_nvm_do_block_op(struct mtd_info *mtd, loff_t start_add,
234 uint64_t len, u_char block_op)
235 {
236 struct map_info *map = mtd->priv;
237 u_long add, end_add;
238 int ret = 0;
239
240 mutex_lock(&lpdd2_nvm_mutex);
241
242 ow_enable(map);
243
244 add = start_add;
245 end_add = add + len;
246
247 do {
248 ret = lpddr2_nvm_do_op(map, block_op, 0x00, add, add, NULL);
249 if (ret)
250 goto out;
251 add += mtd->erasesize;
252 } while (add < end_add);
253
254 out:
255 ow_disable(map);
256 mutex_unlock(&lpdd2_nvm_mutex);
257 return ret;
258 }
259
260 /*
261 * verify presence of PFOW string
262 */
lpddr2_nvm_pfow_present(struct map_info * map)263 static int lpddr2_nvm_pfow_present(struct map_info *map)
264 {
265 map_word pfow_val[4];
266 unsigned int found = 1;
267
268 mutex_lock(&lpdd2_nvm_mutex);
269
270 ow_enable(map);
271
272 /* Load string from array */
273 pfow_val[0] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_P));
274 pfow_val[1] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_F));
275 pfow_val[2] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_O));
276 pfow_val[3] = map_read(map, ow_reg_add(map, PFOW_QUERY_STRING_W));
277
278 /* Verify the string loaded vs expected */
279 if (!map_word_equal(map, build_map_word('P'), pfow_val[0]))
280 found = 0;
281 if (!map_word_equal(map, build_map_word('F'), pfow_val[1]))
282 found = 0;
283 if (!map_word_equal(map, build_map_word('O'), pfow_val[2]))
284 found = 0;
285 if (!map_word_equal(map, build_map_word('W'), pfow_val[3]))
286 found = 0;
287
288 ow_disable(map);
289
290 mutex_unlock(&lpdd2_nvm_mutex);
291
292 return found;
293 }
294
295 /*
296 * lpddr2_nvm driver read method
297 */
lpddr2_nvm_read(struct mtd_info * mtd,loff_t start_add,size_t len,size_t * retlen,u_char * buf)298 static int lpddr2_nvm_read(struct mtd_info *mtd, loff_t start_add,
299 size_t len, size_t *retlen, u_char *buf)
300 {
301 struct map_info *map = mtd->priv;
302
303 mutex_lock(&lpdd2_nvm_mutex);
304
305 *retlen = len;
306
307 map_copy_from(map, buf, start_add, *retlen);
308
309 mutex_unlock(&lpdd2_nvm_mutex);
310 return 0;
311 }
312
313 /*
314 * lpddr2_nvm driver write method
315 */
lpddr2_nvm_write(struct mtd_info * mtd,loff_t start_add,size_t len,size_t * retlen,const u_char * buf)316 static int lpddr2_nvm_write(struct mtd_info *mtd, loff_t start_add,
317 size_t len, size_t *retlen, const u_char *buf)
318 {
319 struct map_info *map = mtd->priv;
320 struct pcm_int_data *pcm_data = map->fldrv_priv;
321 u_long add, current_len, tot_len, target_len, my_data;
322 u_char *write_buf = (u_char *)buf;
323 int ret = 0;
324
325 mutex_lock(&lpdd2_nvm_mutex);
326
327 ow_enable(map);
328
329 /* Set start value for the variables */
330 add = start_add;
331 target_len = len;
332 tot_len = 0;
333
334 while (tot_len < target_len) {
335 if (!(IS_ALIGNED(add, mtd->writesize))) { /* do sw program */
336 my_data = write_buf[tot_len];
337 my_data += (write_buf[tot_len+1]) << 8;
338 if (pcm_data->bus_width == 0x0004) {/* 2x16 devices */
339 my_data += (write_buf[tot_len+2]) << 16;
340 my_data += (write_buf[tot_len+3]) << 24;
341 }
342 ret = lpddr2_nvm_do_op(map, LPDDR2_NVM_SW_OVERWRITE,
343 my_data, add, 0x00, NULL);
344 if (ret)
345 goto out;
346
347 add += pcm_data->bus_width;
348 tot_len += pcm_data->bus_width;
349 } else { /* do buffer program */
350 current_len = min(target_len - tot_len,
351 (u_long) mtd->writesize);
352 ret = lpddr2_nvm_do_op(map, LPDDR2_NVM_BUF_OVERWRITE,
353 0x00, add, current_len, write_buf + tot_len);
354 if (ret)
355 goto out;
356
357 add += current_len;
358 tot_len += current_len;
359 }
360 }
361
362 out:
363 *retlen = tot_len;
364 ow_disable(map);
365 mutex_unlock(&lpdd2_nvm_mutex);
366 return ret;
367 }
368
369 /*
370 * lpddr2_nvm driver erase method
371 */
lpddr2_nvm_erase(struct mtd_info * mtd,struct erase_info * instr)372 static int lpddr2_nvm_erase(struct mtd_info *mtd, struct erase_info *instr)
373 {
374 return lpddr2_nvm_do_block_op(mtd, instr->addr, instr->len,
375 LPDDR2_NVM_ERASE);
376 }
377
378 /*
379 * lpddr2_nvm driver unlock method
380 */
lpddr2_nvm_unlock(struct mtd_info * mtd,loff_t start_add,uint64_t len)381 static int lpddr2_nvm_unlock(struct mtd_info *mtd, loff_t start_add,
382 uint64_t len)
383 {
384 return lpddr2_nvm_do_block_op(mtd, start_add, len, LPDDR2_NVM_UNLOCK);
385 }
386
387 /*
388 * lpddr2_nvm driver lock method
389 */
lpddr2_nvm_lock(struct mtd_info * mtd,loff_t start_add,uint64_t len)390 static int lpddr2_nvm_lock(struct mtd_info *mtd, loff_t start_add,
391 uint64_t len)
392 {
393 return lpddr2_nvm_do_block_op(mtd, start_add, len, LPDDR2_NVM_LOCK);
394 }
395
396 static const struct mtd_info lpddr2_nvm_mtd_info = {
397 .type = MTD_RAM,
398 .writesize = 1,
399 .flags = (MTD_CAP_NVRAM | MTD_POWERUP_LOCK),
400 ._read = lpddr2_nvm_read,
401 ._write = lpddr2_nvm_write,
402 ._erase = lpddr2_nvm_erase,
403 ._unlock = lpddr2_nvm_unlock,
404 ._lock = lpddr2_nvm_lock,
405 };
406
407 /*
408 * lpddr2_nvm driver probe method
409 */
lpddr2_nvm_probe(struct platform_device * pdev)410 static int lpddr2_nvm_probe(struct platform_device *pdev)
411 {
412 struct map_info *map;
413 struct mtd_info *mtd;
414 struct resource *add_range;
415 struct pcm_int_data *pcm_data;
416
417 /* Allocate memory control_regs data structures */
418 pcm_data = devm_kzalloc(&pdev->dev, sizeof(*pcm_data), GFP_KERNEL);
419 if (!pcm_data)
420 return -ENOMEM;
421
422 pcm_data->bus_width = BUS_WIDTH;
423
424 /* Allocate memory for map_info & mtd_info data structures */
425 map = devm_kzalloc(&pdev->dev, sizeof(*map), GFP_KERNEL);
426 if (!map)
427 return -ENOMEM;
428
429 mtd = devm_kzalloc(&pdev->dev, sizeof(*mtd), GFP_KERNEL);
430 if (!mtd)
431 return -ENOMEM;
432
433 /* lpddr2_nvm address range */
434 add_range = platform_get_resource(pdev, IORESOURCE_MEM, 0);
435 if (!add_range)
436 return -ENODEV;
437
438 /* Populate map_info data structure */
439 *map = (struct map_info) {
440 .virt = devm_ioremap_resource(&pdev->dev, add_range),
441 .name = pdev->dev.init_name,
442 .phys = add_range->start,
443 .size = resource_size(add_range),
444 .bankwidth = pcm_data->bus_width / 2,
445 .pfow_base = OW_BASE_ADDRESS,
446 .fldrv_priv = pcm_data,
447 };
448
449 if (IS_ERR(map->virt))
450 return PTR_ERR(map->virt);
451
452 simple_map_init(map); /* fill with default methods */
453
454 pcm_data->ctl_regs = devm_platform_ioremap_resource(pdev, 1);
455 if (IS_ERR(pcm_data->ctl_regs))
456 return PTR_ERR(pcm_data->ctl_regs);
457
458 /* Populate mtd_info data structure */
459 *mtd = lpddr2_nvm_mtd_info;
460 mtd->dev.parent = &pdev->dev;
461 mtd->name = pdev->dev.init_name;
462 mtd->priv = map;
463 mtd->size = resource_size(add_range);
464 mtd->erasesize = ERASE_BLOCKSIZE * pcm_data->bus_width;
465 mtd->writebufsize = WRITE_BUFFSIZE * pcm_data->bus_width;
466
467 /* Verify the presence of the device looking for PFOW string */
468 if (!lpddr2_nvm_pfow_present(map)) {
469 pr_err("device not recognized\n");
470 return -EINVAL;
471 }
472 /* Parse partitions and register the MTD device */
473 return mtd_device_register(mtd, NULL, 0);
474 }
475
476 /*
477 * lpddr2_nvm driver remove method
478 */
lpddr2_nvm_remove(struct platform_device * pdev)479 static void lpddr2_nvm_remove(struct platform_device *pdev)
480 {
481 WARN_ON(mtd_device_unregister(dev_get_drvdata(&pdev->dev)));
482 }
483
484 /* Initialize platform_driver data structure for lpddr2_nvm */
485 static struct platform_driver lpddr2_nvm_drv = {
486 .driver = {
487 .name = "lpddr2_nvm",
488 },
489 .probe = lpddr2_nvm_probe,
490 .remove = lpddr2_nvm_remove,
491 };
492
493 module_platform_driver(lpddr2_nvm_drv);
494 MODULE_LICENSE("GPL");
495 MODULE_AUTHOR("Vincenzo Aliberti <vincenzo.aliberti@gmail.com>");
496 MODULE_DESCRIPTION("MTD driver for LPDDR2-NVM PCM memories");
497