1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SPI NOR driver for NXP SPI Flash Interface (SPIFI)
4  *
5  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
6  *
7  * Based on Freescale QuadSPI driver:
8  * Copyright (C) 2013 Freescale Semiconductor, Inc.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/iopoll.h>
15 #include <linux/module.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/partitions.h>
18 #include <linux/mtd/spi-nor.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/platform_device.h>
22 #include <linux/spi/spi.h>
23 
24 /* NXP SPIFI registers, bits and macros */
25 #define SPIFI_CTRL				0x000
26 #define  SPIFI_CTRL_TIMEOUT(timeout)		(timeout)
27 #define  SPIFI_CTRL_CSHIGH(cshigh)		((cshigh) << 16)
28 #define  SPIFI_CTRL_MODE3			BIT(23)
29 #define  SPIFI_CTRL_DUAL			BIT(28)
30 #define  SPIFI_CTRL_FBCLK			BIT(30)
31 #define SPIFI_CMD				0x004
32 #define  SPIFI_CMD_DATALEN(dlen)		((dlen) & 0x3fff)
33 #define  SPIFI_CMD_DOUT				BIT(15)
34 #define  SPIFI_CMD_INTLEN(ilen)			((ilen) << 16)
35 #define  SPIFI_CMD_FIELDFORM(field)		((field) << 19)
36 #define  SPIFI_CMD_FIELDFORM_ALL_SERIAL		SPIFI_CMD_FIELDFORM(0x0)
37 #define  SPIFI_CMD_FIELDFORM_QUAD_DUAL_DATA	SPIFI_CMD_FIELDFORM(0x1)
38 #define  SPIFI_CMD_FRAMEFORM(frame)		((frame) << 21)
39 #define  SPIFI_CMD_FRAMEFORM_OPCODE_ONLY	SPIFI_CMD_FRAMEFORM(0x1)
40 #define  SPIFI_CMD_OPCODE(op)			((op) << 24)
41 #define SPIFI_ADDR				0x008
42 #define SPIFI_IDATA				0x00c
43 #define SPIFI_CLIMIT				0x010
44 #define SPIFI_DATA				0x014
45 #define SPIFI_MCMD				0x018
46 #define SPIFI_STAT				0x01c
47 #define  SPIFI_STAT_MCINIT			BIT(0)
48 #define  SPIFI_STAT_CMD				BIT(1)
49 #define  SPIFI_STAT_RESET			BIT(4)
50 
51 #define SPI_NOR_MAX_ID_LEN	6
52 
53 struct nxp_spifi {
54 	struct device *dev;
55 	struct clk *clk_spifi;
56 	struct clk *clk_reg;
57 	void __iomem *io_base;
58 	void __iomem *flash_base;
59 	struct spi_nor nor;
60 	bool memory_mode;
61 	u32 mcmd;
62 };
63 
64 static int nxp_spifi_wait_for_cmd(struct nxp_spifi *spifi)
65 {
66 	u8 stat;
67 	int ret;
68 
69 	ret = readb_poll_timeout(spifi->io_base + SPIFI_STAT, stat,
70 				 !(stat & SPIFI_STAT_CMD), 10, 30);
71 	if (ret)
72 		dev_warn(spifi->dev, "command timed out\n");
73 
74 	return ret;
75 }
76 
77 static int nxp_spifi_reset(struct nxp_spifi *spifi)
78 {
79 	u8 stat;
80 	int ret;
81 
82 	writel(SPIFI_STAT_RESET, spifi->io_base + SPIFI_STAT);
83 	ret = readb_poll_timeout(spifi->io_base + SPIFI_STAT, stat,
84 				 !(stat & SPIFI_STAT_RESET), 10, 30);
85 	if (ret)
86 		dev_warn(spifi->dev, "state reset timed out\n");
87 
88 	return ret;
89 }
90 
91 static int nxp_spifi_set_memory_mode_off(struct nxp_spifi *spifi)
92 {
93 	int ret;
94 
95 	if (!spifi->memory_mode)
96 		return 0;
97 
98 	ret = nxp_spifi_reset(spifi);
99 	if (ret)
100 		dev_err(spifi->dev, "unable to enter command mode\n");
101 	else
102 		spifi->memory_mode = false;
103 
104 	return ret;
105 }
106 
107 static int nxp_spifi_set_memory_mode_on(struct nxp_spifi *spifi)
108 {
109 	u8 stat;
110 	int ret;
111 
112 	if (spifi->memory_mode)
113 		return 0;
114 
115 	writel(spifi->mcmd, spifi->io_base + SPIFI_MCMD);
116 	ret = readb_poll_timeout(spifi->io_base + SPIFI_STAT, stat,
117 				 stat & SPIFI_STAT_MCINIT, 10, 30);
118 	if (ret)
119 		dev_err(spifi->dev, "unable to enter memory mode\n");
120 	else
121 		spifi->memory_mode = true;
122 
123 	return ret;
124 }
125 
126 static int nxp_spifi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
127 			      size_t len)
128 {
129 	struct nxp_spifi *spifi = nor->priv;
130 	u32 cmd;
131 	int ret;
132 
133 	ret = nxp_spifi_set_memory_mode_off(spifi);
134 	if (ret)
135 		return ret;
136 
137 	cmd = SPIFI_CMD_DATALEN(len) |
138 	      SPIFI_CMD_OPCODE(opcode) |
139 	      SPIFI_CMD_FIELDFORM_ALL_SERIAL |
140 	      SPIFI_CMD_FRAMEFORM_OPCODE_ONLY;
141 	writel(cmd, spifi->io_base + SPIFI_CMD);
142 
143 	while (len--)
144 		*buf++ = readb(spifi->io_base + SPIFI_DATA);
145 
146 	return nxp_spifi_wait_for_cmd(spifi);
147 }
148 
149 static int nxp_spifi_write_reg(struct spi_nor *nor, u8 opcode, const u8 *buf,
150 			       size_t len)
151 {
152 	struct nxp_spifi *spifi = nor->priv;
153 	u32 cmd;
154 	int ret;
155 
156 	ret = nxp_spifi_set_memory_mode_off(spifi);
157 	if (ret)
158 		return ret;
159 
160 	cmd = SPIFI_CMD_DOUT |
161 	      SPIFI_CMD_DATALEN(len) |
162 	      SPIFI_CMD_OPCODE(opcode) |
163 	      SPIFI_CMD_FIELDFORM_ALL_SERIAL |
164 	      SPIFI_CMD_FRAMEFORM_OPCODE_ONLY;
165 	writel(cmd, spifi->io_base + SPIFI_CMD);
166 
167 	while (len--)
168 		writeb(*buf++, spifi->io_base + SPIFI_DATA);
169 
170 	return nxp_spifi_wait_for_cmd(spifi);
171 }
172 
173 static ssize_t nxp_spifi_read(struct spi_nor *nor, loff_t from, size_t len,
174 			      u_char *buf)
175 {
176 	struct nxp_spifi *spifi = nor->priv;
177 	int ret;
178 
179 	ret = nxp_spifi_set_memory_mode_on(spifi);
180 	if (ret)
181 		return ret;
182 
183 	memcpy_fromio(buf, spifi->flash_base + from, len);
184 
185 	return len;
186 }
187 
188 static ssize_t nxp_spifi_write(struct spi_nor *nor, loff_t to, size_t len,
189 			       const u_char *buf)
190 {
191 	struct nxp_spifi *spifi = nor->priv;
192 	u32 cmd;
193 	int ret;
194 	size_t i;
195 
196 	ret = nxp_spifi_set_memory_mode_off(spifi);
197 	if (ret)
198 		return ret;
199 
200 	writel(to, spifi->io_base + SPIFI_ADDR);
201 
202 	cmd = SPIFI_CMD_DOUT |
203 	      SPIFI_CMD_DATALEN(len) |
204 	      SPIFI_CMD_FIELDFORM_ALL_SERIAL |
205 	      SPIFI_CMD_OPCODE(nor->program_opcode) |
206 	      SPIFI_CMD_FRAMEFORM(spifi->nor.addr_width + 1);
207 	writel(cmd, spifi->io_base + SPIFI_CMD);
208 
209 	for (i = 0; i < len; i++)
210 		writeb(buf[i], spifi->io_base + SPIFI_DATA);
211 
212 	ret = nxp_spifi_wait_for_cmd(spifi);
213 	if (ret)
214 		return ret;
215 
216 	return len;
217 }
218 
219 static int nxp_spifi_erase(struct spi_nor *nor, loff_t offs)
220 {
221 	struct nxp_spifi *spifi = nor->priv;
222 	u32 cmd;
223 	int ret;
224 
225 	ret = nxp_spifi_set_memory_mode_off(spifi);
226 	if (ret)
227 		return ret;
228 
229 	writel(offs, spifi->io_base + SPIFI_ADDR);
230 
231 	cmd = SPIFI_CMD_FIELDFORM_ALL_SERIAL |
232 	      SPIFI_CMD_OPCODE(nor->erase_opcode) |
233 	      SPIFI_CMD_FRAMEFORM(spifi->nor.addr_width + 1);
234 	writel(cmd, spifi->io_base + SPIFI_CMD);
235 
236 	return nxp_spifi_wait_for_cmd(spifi);
237 }
238 
239 static int nxp_spifi_setup_memory_cmd(struct nxp_spifi *spifi)
240 {
241 	switch (spifi->nor.read_proto) {
242 	case SNOR_PROTO_1_1_1:
243 		spifi->mcmd = SPIFI_CMD_FIELDFORM_ALL_SERIAL;
244 		break;
245 	case SNOR_PROTO_1_1_2:
246 	case SNOR_PROTO_1_1_4:
247 		spifi->mcmd = SPIFI_CMD_FIELDFORM_QUAD_DUAL_DATA;
248 		break;
249 	default:
250 		dev_err(spifi->dev, "unsupported SPI read mode\n");
251 		return -EINVAL;
252 	}
253 
254 	/* Memory mode supports address length between 1 and 4 */
255 	if (spifi->nor.addr_width < 1 || spifi->nor.addr_width > 4)
256 		return -EINVAL;
257 
258 	spifi->mcmd |= SPIFI_CMD_OPCODE(spifi->nor.read_opcode) |
259 		       SPIFI_CMD_INTLEN(spifi->nor.read_dummy / 8) |
260 		       SPIFI_CMD_FRAMEFORM(spifi->nor.addr_width + 1);
261 
262 	return 0;
263 }
264 
265 static void nxp_spifi_dummy_id_read(struct spi_nor *nor)
266 {
267 	u8 id[SPI_NOR_MAX_ID_LEN];
268 	nor->controller_ops->read_reg(nor, SPINOR_OP_RDID, id,
269 				      SPI_NOR_MAX_ID_LEN);
270 }
271 
272 static const struct spi_nor_controller_ops nxp_spifi_controller_ops = {
273 	.read_reg  = nxp_spifi_read_reg,
274 	.write_reg = nxp_spifi_write_reg,
275 	.read  = nxp_spifi_read,
276 	.write = nxp_spifi_write,
277 	.erase = nxp_spifi_erase,
278 };
279 
280 static int nxp_spifi_setup_flash(struct nxp_spifi *spifi,
281 				 struct device_node *np)
282 {
283 	struct spi_nor_hwcaps hwcaps = {
284 		.mask = SNOR_HWCAPS_READ |
285 			SNOR_HWCAPS_READ_FAST |
286 			SNOR_HWCAPS_PP,
287 	};
288 	u32 ctrl, property;
289 	u16 mode = 0;
290 	int ret;
291 
292 	if (!of_property_read_u32(np, "spi-rx-bus-width", &property)) {
293 		switch (property) {
294 		case 1:
295 			break;
296 		case 2:
297 			mode |= SPI_RX_DUAL;
298 			break;
299 		case 4:
300 			mode |= SPI_RX_QUAD;
301 			break;
302 		default:
303 			dev_err(spifi->dev, "unsupported rx-bus-width\n");
304 			return -EINVAL;
305 		}
306 	}
307 
308 	if (of_find_property(np, "spi-cpha", NULL))
309 		mode |= SPI_CPHA;
310 
311 	if (of_find_property(np, "spi-cpol", NULL))
312 		mode |= SPI_CPOL;
313 
314 	/* Setup control register defaults */
315 	ctrl = SPIFI_CTRL_TIMEOUT(1000) |
316 	       SPIFI_CTRL_CSHIGH(15) |
317 	       SPIFI_CTRL_FBCLK;
318 
319 	if (mode & SPI_RX_DUAL) {
320 		ctrl |= SPIFI_CTRL_DUAL;
321 		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
322 	} else if (mode & SPI_RX_QUAD) {
323 		ctrl &= ~SPIFI_CTRL_DUAL;
324 		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
325 	} else {
326 		ctrl |= SPIFI_CTRL_DUAL;
327 	}
328 
329 	switch (mode & SPI_MODE_X_MASK) {
330 	case SPI_MODE_0:
331 		ctrl &= ~SPIFI_CTRL_MODE3;
332 		break;
333 	case SPI_MODE_3:
334 		ctrl |= SPIFI_CTRL_MODE3;
335 		break;
336 	default:
337 		dev_err(spifi->dev, "only mode 0 and 3 supported\n");
338 		return -EINVAL;
339 	}
340 
341 	writel(ctrl, spifi->io_base + SPIFI_CTRL);
342 
343 	spifi->nor.dev   = spifi->dev;
344 	spi_nor_set_flash_node(&spifi->nor, np);
345 	spifi->nor.priv  = spifi;
346 	spifi->nor.controller_ops = &nxp_spifi_controller_ops;
347 
348 	/*
349 	 * The first read on a hard reset isn't reliable so do a
350 	 * dummy read of the id before calling spi_nor_scan().
351 	 * The reason for this problem is unknown.
352 	 *
353 	 * The official NXP spifilib uses more or less the same
354 	 * workaround that is applied here by reading the device
355 	 * id multiple times.
356 	 */
357 	nxp_spifi_dummy_id_read(&spifi->nor);
358 
359 	ret = spi_nor_scan(&spifi->nor, NULL, &hwcaps);
360 	if (ret) {
361 		dev_err(spifi->dev, "device scan failed\n");
362 		return ret;
363 	}
364 
365 	ret = nxp_spifi_setup_memory_cmd(spifi);
366 	if (ret) {
367 		dev_err(spifi->dev, "memory command setup failed\n");
368 		return ret;
369 	}
370 
371 	ret = mtd_device_register(&spifi->nor.mtd, NULL, 0);
372 	if (ret) {
373 		dev_err(spifi->dev, "mtd device parse failed\n");
374 		return ret;
375 	}
376 
377 	return 0;
378 }
379 
380 static int nxp_spifi_probe(struct platform_device *pdev)
381 {
382 	struct device_node *flash_np;
383 	struct nxp_spifi *spifi;
384 	int ret;
385 
386 	spifi = devm_kzalloc(&pdev->dev, sizeof(*spifi), GFP_KERNEL);
387 	if (!spifi)
388 		return -ENOMEM;
389 
390 	spifi->io_base = devm_platform_ioremap_resource_byname(pdev, "spifi");
391 	if (IS_ERR(spifi->io_base))
392 		return PTR_ERR(spifi->io_base);
393 
394 	spifi->flash_base = devm_platform_ioremap_resource_byname(pdev, "flash");
395 	if (IS_ERR(spifi->flash_base))
396 		return PTR_ERR(spifi->flash_base);
397 
398 	spifi->clk_spifi = devm_clk_get(&pdev->dev, "spifi");
399 	if (IS_ERR(spifi->clk_spifi)) {
400 		dev_err(&pdev->dev, "spifi clock not found\n");
401 		return PTR_ERR(spifi->clk_spifi);
402 	}
403 
404 	spifi->clk_reg = devm_clk_get(&pdev->dev, "reg");
405 	if (IS_ERR(spifi->clk_reg)) {
406 		dev_err(&pdev->dev, "reg clock not found\n");
407 		return PTR_ERR(spifi->clk_reg);
408 	}
409 
410 	ret = clk_prepare_enable(spifi->clk_reg);
411 	if (ret) {
412 		dev_err(&pdev->dev, "unable to enable reg clock\n");
413 		return ret;
414 	}
415 
416 	ret = clk_prepare_enable(spifi->clk_spifi);
417 	if (ret) {
418 		dev_err(&pdev->dev, "unable to enable spifi clock\n");
419 		goto dis_clk_reg;
420 	}
421 
422 	spifi->dev = &pdev->dev;
423 	platform_set_drvdata(pdev, spifi);
424 
425 	/* Initialize and reset device */
426 	nxp_spifi_reset(spifi);
427 	writel(0, spifi->io_base + SPIFI_IDATA);
428 	writel(0, spifi->io_base + SPIFI_MCMD);
429 	nxp_spifi_reset(spifi);
430 
431 	flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
432 	if (!flash_np) {
433 		dev_err(&pdev->dev, "no SPI flash device to configure\n");
434 		ret = -ENODEV;
435 		goto dis_clks;
436 	}
437 
438 	ret = nxp_spifi_setup_flash(spifi, flash_np);
439 	of_node_put(flash_np);
440 	if (ret) {
441 		dev_err(&pdev->dev, "unable to setup flash chip\n");
442 		goto dis_clks;
443 	}
444 
445 	return 0;
446 
447 dis_clks:
448 	clk_disable_unprepare(spifi->clk_spifi);
449 dis_clk_reg:
450 	clk_disable_unprepare(spifi->clk_reg);
451 	return ret;
452 }
453 
454 static int nxp_spifi_remove(struct platform_device *pdev)
455 {
456 	struct nxp_spifi *spifi = platform_get_drvdata(pdev);
457 
458 	mtd_device_unregister(&spifi->nor.mtd);
459 	clk_disable_unprepare(spifi->clk_spifi);
460 	clk_disable_unprepare(spifi->clk_reg);
461 
462 	return 0;
463 }
464 
465 static const struct of_device_id nxp_spifi_match[] = {
466 	{.compatible = "nxp,lpc1773-spifi"},
467 	{ /* sentinel */ }
468 };
469 MODULE_DEVICE_TABLE(of, nxp_spifi_match);
470 
471 static struct platform_driver nxp_spifi_driver = {
472 	.probe	= nxp_spifi_probe,
473 	.remove	= nxp_spifi_remove,
474 	.driver	= {
475 		.name = "nxp-spifi",
476 		.of_match_table = nxp_spifi_match,
477 	},
478 };
479 module_platform_driver(nxp_spifi_driver);
480 
481 MODULE_DESCRIPTION("NXP SPI Flash Interface driver");
482 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
483 MODULE_LICENSE("GPL v2");
484