xref: /openbmc/linux/drivers/mtd/nand/raw/cs553x_nand.c (revision b8265621)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * (C) 2005, 2006 Red Hat Inc.
4  *
5  * Author: David Woodhouse <dwmw2@infradead.org>
6  *	   Tom Sylla <tom.sylla@amd.com>
7  *
8  *  Overview:
9  *   This is a device driver for the NAND flash controller found on
10  *   the AMD CS5535/CS5536 companion chipsets for the Geode processor.
11  *   mtd-id for command line partitioning is cs553x_nand_cs[0-3]
12  *   where 0-3 reflects the chip select for NAND.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/delay.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/rawnand.h>
22 #include <linux/mtd/nand_ecc.h>
23 #include <linux/mtd/partitions.h>
24 #include <linux/iopoll.h>
25 
26 #include <asm/msr.h>
27 
28 #define NR_CS553X_CONTROLLERS	4
29 
30 #define MSR_DIVIL_GLD_CAP	0x51400000	/* DIVIL capabilitiies */
31 #define CAP_CS5535		0x2df000ULL
32 #define CAP_CS5536		0x5df500ULL
33 
34 /* NAND Timing MSRs */
35 #define MSR_NANDF_DATA		0x5140001b	/* NAND Flash Data Timing MSR */
36 #define MSR_NANDF_CTL		0x5140001c	/* NAND Flash Control Timing */
37 #define MSR_NANDF_RSVD		0x5140001d	/* Reserved */
38 
39 /* NAND BAR MSRs */
40 #define MSR_DIVIL_LBAR_FLSH0	0x51400010	/* Flash Chip Select 0 */
41 #define MSR_DIVIL_LBAR_FLSH1	0x51400011	/* Flash Chip Select 1 */
42 #define MSR_DIVIL_LBAR_FLSH2	0x51400012	/* Flash Chip Select 2 */
43 #define MSR_DIVIL_LBAR_FLSH3	0x51400013	/* Flash Chip Select 3 */
44 	/* Each made up of... */
45 #define FLSH_LBAR_EN		(1ULL<<32)
46 #define FLSH_NOR_NAND		(1ULL<<33)	/* 1 for NAND */
47 #define FLSH_MEM_IO		(1ULL<<34)	/* 1 for MMIO */
48 	/* I/O BARs have BASE_ADDR in bits 15:4, IO_MASK in 47:36 */
49 	/* MMIO BARs have BASE_ADDR in bits 31:12, MEM_MASK in 63:44 */
50 
51 /* Pin function selection MSR (IDE vs. flash on the IDE pins) */
52 #define MSR_DIVIL_BALL_OPTS	0x51400015
53 #define PIN_OPT_IDE		(1<<0)	/* 0 for flash, 1 for IDE */
54 
55 /* Registers within the NAND flash controller BAR -- memory mapped */
56 #define MM_NAND_DATA		0x00	/* 0 to 0x7ff, in fact */
57 #define MM_NAND_CTL		0x800	/* Any even address 0x800-0x80e */
58 #define MM_NAND_IO		0x801	/* Any odd address 0x801-0x80f */
59 #define MM_NAND_STS		0x810
60 #define MM_NAND_ECC_LSB		0x811
61 #define MM_NAND_ECC_MSB		0x812
62 #define MM_NAND_ECC_COL		0x813
63 #define MM_NAND_LAC		0x814
64 #define MM_NAND_ECC_CTL		0x815
65 
66 /* Registers within the NAND flash controller BAR -- I/O mapped */
67 #define IO_NAND_DATA		0x00	/* 0 to 3, in fact */
68 #define IO_NAND_CTL		0x04
69 #define IO_NAND_IO		0x05
70 #define IO_NAND_STS		0x06
71 #define IO_NAND_ECC_CTL		0x08
72 #define IO_NAND_ECC_LSB		0x09
73 #define IO_NAND_ECC_MSB		0x0a
74 #define IO_NAND_ECC_COL		0x0b
75 #define IO_NAND_LAC		0x0c
76 
77 #define CS_NAND_CTL_DIST_EN	(1<<4)	/* Enable NAND Distract interrupt */
78 #define CS_NAND_CTL_RDY_INT_MASK	(1<<3)	/* Enable RDY/BUSY# interrupt */
79 #define CS_NAND_CTL_ALE		(1<<2)
80 #define CS_NAND_CTL_CLE		(1<<1)
81 #define CS_NAND_CTL_CE		(1<<0)	/* Keep low; 1 to reset */
82 
83 #define CS_NAND_STS_FLASH_RDY	(1<<3)
84 #define CS_NAND_CTLR_BUSY	(1<<2)
85 #define CS_NAND_CMD_COMP	(1<<1)
86 #define CS_NAND_DIST_ST		(1<<0)
87 
88 #define CS_NAND_ECC_PARITY	(1<<2)
89 #define CS_NAND_ECC_CLRECC	(1<<1)
90 #define CS_NAND_ECC_ENECC	(1<<0)
91 
92 struct cs553x_nand_controller {
93 	struct nand_controller base;
94 	struct nand_chip chip;
95 	void __iomem *mmio;
96 };
97 
98 static struct cs553x_nand_controller *
99 to_cs553x(struct nand_controller *controller)
100 {
101 	return container_of(controller, struct cs553x_nand_controller, base);
102 }
103 
104 static int cs553x_write_ctrl_byte(struct cs553x_nand_controller *cs553x,
105 				  u32 ctl, u8 data)
106 {
107 	u8 status;
108 	int ret;
109 
110 	writeb(ctl, cs553x->mmio + MM_NAND_CTL);
111 	writeb(data, cs553x->mmio + MM_NAND_IO);
112 	ret = readb_poll_timeout_atomic(cs553x->mmio + MM_NAND_STS, status,
113 					!(status & CS_NAND_CTLR_BUSY), 1,
114 					100000);
115 	if (ret)
116 		return ret;
117 
118 	return 0;
119 }
120 
121 static void cs553x_data_in(struct cs553x_nand_controller *cs553x, void *buf,
122 			   unsigned int len)
123 {
124 	writeb(0, cs553x->mmio + MM_NAND_CTL);
125 	while (unlikely(len > 0x800)) {
126 		memcpy_fromio(buf, cs553x->mmio, 0x800);
127 		buf += 0x800;
128 		len -= 0x800;
129 	}
130 	memcpy_fromio(buf, cs553x->mmio, len);
131 }
132 
133 static void cs553x_data_out(struct cs553x_nand_controller *cs553x,
134 			    const void *buf, unsigned int len)
135 {
136 	writeb(0, cs553x->mmio + MM_NAND_CTL);
137 	while (unlikely(len > 0x800)) {
138 		memcpy_toio(cs553x->mmio, buf, 0x800);
139 		buf += 0x800;
140 		len -= 0x800;
141 	}
142 	memcpy_toio(cs553x->mmio, buf, len);
143 }
144 
145 static int cs553x_wait_ready(struct cs553x_nand_controller *cs553x,
146 			     unsigned int timeout_ms)
147 {
148 	u8 mask = CS_NAND_CTLR_BUSY | CS_NAND_STS_FLASH_RDY;
149 	u8 status;
150 
151 	return readb_poll_timeout(cs553x->mmio + MM_NAND_STS, status,
152 				  (status & mask) == CS_NAND_STS_FLASH_RDY, 100,
153 				  timeout_ms * 1000);
154 }
155 
156 static int cs553x_exec_instr(struct cs553x_nand_controller *cs553x,
157 			     const struct nand_op_instr *instr)
158 {
159 	unsigned int i;
160 	int ret = 0;
161 
162 	switch (instr->type) {
163 	case NAND_OP_CMD_INSTR:
164 		ret = cs553x_write_ctrl_byte(cs553x, CS_NAND_CTL_CLE,
165 					     instr->ctx.cmd.opcode);
166 		break;
167 
168 	case NAND_OP_ADDR_INSTR:
169 		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
170 			ret = cs553x_write_ctrl_byte(cs553x, CS_NAND_CTL_ALE,
171 						     instr->ctx.addr.addrs[i]);
172 			if (ret)
173 				break;
174 		}
175 		break;
176 
177 	case NAND_OP_DATA_IN_INSTR:
178 		cs553x_data_in(cs553x, instr->ctx.data.buf.in,
179 			       instr->ctx.data.len);
180 		break;
181 
182 	case NAND_OP_DATA_OUT_INSTR:
183 		cs553x_data_out(cs553x, instr->ctx.data.buf.out,
184 				instr->ctx.data.len);
185 		break;
186 
187 	case NAND_OP_WAITRDY_INSTR:
188 		ret = cs553x_wait_ready(cs553x, instr->ctx.waitrdy.timeout_ms);
189 		break;
190 	}
191 
192 	if (instr->delay_ns)
193 		ndelay(instr->delay_ns);
194 
195 	return ret;
196 }
197 
198 static int cs553x_exec_op(struct nand_chip *this,
199 			  const struct nand_operation *op,
200 			  bool check_only)
201 {
202 	struct cs553x_nand_controller *cs553x = to_cs553x(this->controller);
203 	unsigned int i;
204 	int ret;
205 
206 	if (check_only)
207 		return true;
208 
209 	/* De-assert the CE pin */
210 	writeb(0, cs553x->mmio + MM_NAND_CTL);
211 	for (i = 0; i < op->ninstrs; i++) {
212 		ret = cs553x_exec_instr(cs553x, &op->instrs[i]);
213 		if (ret)
214 			break;
215 	}
216 
217 	/* Re-assert the CE pin. */
218 	writeb(CS_NAND_CTL_CE, cs553x->mmio + MM_NAND_CTL);
219 
220 	return ret;
221 }
222 
223 static void cs_enable_hwecc(struct nand_chip *this, int mode)
224 {
225 	struct cs553x_nand_controller *cs553x = to_cs553x(this->controller);
226 
227 	writeb(0x07, cs553x->mmio + MM_NAND_ECC_CTL);
228 }
229 
230 static int cs_calculate_ecc(struct nand_chip *this, const u_char *dat,
231 			    u_char *ecc_code)
232 {
233 	struct cs553x_nand_controller *cs553x = to_cs553x(this->controller);
234 	uint32_t ecc;
235 
236 	ecc = readl(cs553x->mmio + MM_NAND_STS);
237 
238 	ecc_code[1] = ecc >> 8;
239 	ecc_code[0] = ecc >> 16;
240 	ecc_code[2] = ecc >> 24;
241 	return 0;
242 }
243 
244 static struct cs553x_nand_controller *controllers[4];
245 
246 static const struct nand_controller_ops cs553x_nand_controller_ops = {
247 	.exec_op = cs553x_exec_op,
248 };
249 
250 static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
251 {
252 	struct cs553x_nand_controller *controller;
253 	int err = 0;
254 	struct nand_chip *this;
255 	struct mtd_info *new_mtd;
256 
257 	pr_notice("Probing CS553x NAND controller CS#%d at %sIO 0x%08lx\n",
258 		  cs, mmio ? "MM" : "P", adr);
259 
260 	if (!mmio) {
261 		pr_notice("PIO mode not yet implemented for CS553X NAND controller\n");
262 		return -ENXIO;
263 	}
264 
265 	/* Allocate memory for MTD device structure and private data */
266 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
267 	if (!controller) {
268 		err = -ENOMEM;
269 		goto out;
270 	}
271 
272 	this = &controller->chip;
273 	nand_controller_init(&controller->base);
274 	controller->base.ops = &cs553x_nand_controller_ops;
275 	this->controller = &controller->base;
276 	new_mtd = nand_to_mtd(this);
277 
278 	/* Link the private data with the MTD structure */
279 	new_mtd->owner = THIS_MODULE;
280 
281 	/* map physical address */
282 	controller->mmio = ioremap(adr, 4096);
283 	if (!controller->mmio) {
284 		pr_warn("ioremap cs553x NAND @0x%08lx failed\n", adr);
285 		err = -EIO;
286 		goto out_mtd;
287 	}
288 
289 	this->ecc.mode = NAND_ECC_HW;
290 	this->ecc.size = 256;
291 	this->ecc.bytes = 3;
292 	this->ecc.hwctl  = cs_enable_hwecc;
293 	this->ecc.calculate = cs_calculate_ecc;
294 	this->ecc.correct  = nand_correct_data;
295 	this->ecc.strength = 1;
296 
297 	/* Enable the following for a flash based bad block table */
298 	this->bbt_options = NAND_BBT_USE_FLASH;
299 
300 	new_mtd->name = kasprintf(GFP_KERNEL, "cs553x_nand_cs%d", cs);
301 	if (!new_mtd->name) {
302 		err = -ENOMEM;
303 		goto out_ior;
304 	}
305 
306 	/* Scan to find existence of the device */
307 	err = nand_scan(this, 1);
308 	if (err)
309 		goto out_free;
310 
311 	controllers[cs] = controller;
312 	goto out;
313 
314 out_free:
315 	kfree(new_mtd->name);
316 out_ior:
317 	iounmap(controller->mmio);
318 out_mtd:
319 	kfree(controller);
320 out:
321 	return err;
322 }
323 
324 static int is_geode(void)
325 {
326 	/* These are the CPUs which will have a CS553[56] companion chip */
327 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
328 	    boot_cpu_data.x86 == 5 &&
329 	    boot_cpu_data.x86_model == 10)
330 		return 1; /* Geode LX */
331 
332 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_NSC ||
333 	     boot_cpu_data.x86_vendor == X86_VENDOR_CYRIX) &&
334 	    boot_cpu_data.x86 == 5 &&
335 	    boot_cpu_data.x86_model == 5)
336 		return 1; /* Geode GX (née GX2) */
337 
338 	return 0;
339 }
340 
341 static int __init cs553x_init(void)
342 {
343 	int err = -ENXIO;
344 	int i;
345 	uint64_t val;
346 
347 	/* If the CPU isn't a Geode GX or LX, abort */
348 	if (!is_geode())
349 		return -ENXIO;
350 
351 	/* If it doesn't have the CS553[56], abort */
352 	rdmsrl(MSR_DIVIL_GLD_CAP, val);
353 	val &= ~0xFFULL;
354 	if (val != CAP_CS5535 && val != CAP_CS5536)
355 		return -ENXIO;
356 
357 	/* If it doesn't have the NAND controller enabled, abort */
358 	rdmsrl(MSR_DIVIL_BALL_OPTS, val);
359 	if (val & PIN_OPT_IDE) {
360 		pr_info("CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS.\n");
361 		return -ENXIO;
362 	}
363 
364 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
365 		rdmsrl(MSR_DIVIL_LBAR_FLSH0 + i, val);
366 
367 		if ((val & (FLSH_LBAR_EN|FLSH_NOR_NAND)) == (FLSH_LBAR_EN|FLSH_NOR_NAND))
368 			err = cs553x_init_one(i, !!(val & FLSH_MEM_IO), val & 0xFFFFFFFF);
369 	}
370 
371 	/* Register all devices together here. This means we can easily hack it to
372 	   do mtdconcat etc. if we want to. */
373 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
374 		if (controllers[i]) {
375 			/* If any devices registered, return success. Else the last error. */
376 			mtd_device_register(nand_to_mtd(&controllers[i]->chip),
377 					    NULL, 0);
378 			err = 0;
379 		}
380 	}
381 
382 	return err;
383 }
384 
385 module_init(cs553x_init);
386 
387 static void __exit cs553x_cleanup(void)
388 {
389 	int i;
390 
391 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
392 		struct cs553x_nand_controller *controller = controllers[i];
393 		struct nand_chip *this = &controller->chip;
394 		struct mtd_info *mtd = nand_to_mtd(this);
395 		int ret;
396 
397 		if (!mtd)
398 			continue;
399 
400 		/* Release resources, unregister device */
401 		ret = mtd_device_unregister(mtd);
402 		WARN_ON(ret);
403 		nand_cleanup(this);
404 		kfree(mtd->name);
405 		controllers[i] = NULL;
406 
407 		/* unmap physical address */
408 		iounmap(controller->mmio);
409 
410 		/* Free the MTD device structure */
411 		kfree(controller);
412 	}
413 }
414 
415 module_exit(cs553x_cleanup);
416 
417 MODULE_LICENSE("GPL");
418 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
419 MODULE_DESCRIPTION("NAND controller driver for AMD CS5535/CS5536 companion chip");
420