xref: /openbmc/linux/drivers/mtd/nand/raw/cs553x_nand.c (revision 1edd0337)
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/partitions.h>
23 #include <linux/iopoll.h>
24 
25 #include <asm/msr.h>
26 
27 #define NR_CS553X_CONTROLLERS	4
28 
29 #define MSR_DIVIL_GLD_CAP	0x51400000	/* DIVIL capabilitiies */
30 #define CAP_CS5535		0x2df000ULL
31 #define CAP_CS5536		0x5df500ULL
32 
33 /* NAND Timing MSRs */
34 #define MSR_NANDF_DATA		0x5140001b	/* NAND Flash Data Timing MSR */
35 #define MSR_NANDF_CTL		0x5140001c	/* NAND Flash Control Timing */
36 #define MSR_NANDF_RSVD		0x5140001d	/* Reserved */
37 
38 /* NAND BAR MSRs */
39 #define MSR_DIVIL_LBAR_FLSH0	0x51400010	/* Flash Chip Select 0 */
40 #define MSR_DIVIL_LBAR_FLSH1	0x51400011	/* Flash Chip Select 1 */
41 #define MSR_DIVIL_LBAR_FLSH2	0x51400012	/* Flash Chip Select 2 */
42 #define MSR_DIVIL_LBAR_FLSH3	0x51400013	/* Flash Chip Select 3 */
43 	/* Each made up of... */
44 #define FLSH_LBAR_EN		(1ULL<<32)
45 #define FLSH_NOR_NAND		(1ULL<<33)	/* 1 for NAND */
46 #define FLSH_MEM_IO		(1ULL<<34)	/* 1 for MMIO */
47 	/* I/O BARs have BASE_ADDR in bits 15:4, IO_MASK in 47:36 */
48 	/* MMIO BARs have BASE_ADDR in bits 31:12, MEM_MASK in 63:44 */
49 
50 /* Pin function selection MSR (IDE vs. flash on the IDE pins) */
51 #define MSR_DIVIL_BALL_OPTS	0x51400015
52 #define PIN_OPT_IDE		(1<<0)	/* 0 for flash, 1 for IDE */
53 
54 /* Registers within the NAND flash controller BAR -- memory mapped */
55 #define MM_NAND_DATA		0x00	/* 0 to 0x7ff, in fact */
56 #define MM_NAND_CTL		0x800	/* Any even address 0x800-0x80e */
57 #define MM_NAND_IO		0x801	/* Any odd address 0x801-0x80f */
58 #define MM_NAND_STS		0x810
59 #define MM_NAND_ECC_LSB		0x811
60 #define MM_NAND_ECC_MSB		0x812
61 #define MM_NAND_ECC_COL		0x813
62 #define MM_NAND_LAC		0x814
63 #define MM_NAND_ECC_CTL		0x815
64 
65 /* Registers within the NAND flash controller BAR -- I/O mapped */
66 #define IO_NAND_DATA		0x00	/* 0 to 3, in fact */
67 #define IO_NAND_CTL		0x04
68 #define IO_NAND_IO		0x05
69 #define IO_NAND_STS		0x06
70 #define IO_NAND_ECC_CTL		0x08
71 #define IO_NAND_ECC_LSB		0x09
72 #define IO_NAND_ECC_MSB		0x0a
73 #define IO_NAND_ECC_COL		0x0b
74 #define IO_NAND_LAC		0x0c
75 
76 #define CS_NAND_CTL_DIST_EN	(1<<4)	/* Enable NAND Distract interrupt */
77 #define CS_NAND_CTL_RDY_INT_MASK	(1<<3)	/* Enable RDY/BUSY# interrupt */
78 #define CS_NAND_CTL_ALE		(1<<2)
79 #define CS_NAND_CTL_CLE		(1<<1)
80 #define CS_NAND_CTL_CE		(1<<0)	/* Keep low; 1 to reset */
81 
82 #define CS_NAND_STS_FLASH_RDY	(1<<3)
83 #define CS_NAND_CTLR_BUSY	(1<<2)
84 #define CS_NAND_CMD_COMP	(1<<1)
85 #define CS_NAND_DIST_ST		(1<<0)
86 
87 #define CS_NAND_ECC_PARITY	(1<<2)
88 #define CS_NAND_ECC_CLRECC	(1<<1)
89 #define CS_NAND_ECC_ENECC	(1<<0)
90 
91 struct cs553x_nand_controller {
92 	struct nand_controller base;
93 	struct nand_chip chip;
94 	void __iomem *mmio;
95 };
96 
97 static struct cs553x_nand_controller *
98 to_cs553x(struct nand_controller *controller)
99 {
100 	return container_of(controller, struct cs553x_nand_controller, base);
101 }
102 
103 static int cs553x_write_ctrl_byte(struct cs553x_nand_controller *cs553x,
104 				  u32 ctl, u8 data)
105 {
106 	u8 status;
107 
108 	writeb(ctl, cs553x->mmio + MM_NAND_CTL);
109 	writeb(data, cs553x->mmio + MM_NAND_IO);
110 	return readb_poll_timeout_atomic(cs553x->mmio + MM_NAND_STS, status,
111 					!(status & CS_NAND_CTLR_BUSY), 1,
112 					100000);
113 }
114 
115 static void cs553x_data_in(struct cs553x_nand_controller *cs553x, void *buf,
116 			   unsigned int len)
117 {
118 	writeb(0, cs553x->mmio + MM_NAND_CTL);
119 	while (unlikely(len > 0x800)) {
120 		memcpy_fromio(buf, cs553x->mmio, 0x800);
121 		buf += 0x800;
122 		len -= 0x800;
123 	}
124 	memcpy_fromio(buf, cs553x->mmio, len);
125 }
126 
127 static void cs553x_data_out(struct cs553x_nand_controller *cs553x,
128 			    const void *buf, unsigned int len)
129 {
130 	writeb(0, cs553x->mmio + MM_NAND_CTL);
131 	while (unlikely(len > 0x800)) {
132 		memcpy_toio(cs553x->mmio, buf, 0x800);
133 		buf += 0x800;
134 		len -= 0x800;
135 	}
136 	memcpy_toio(cs553x->mmio, buf, len);
137 }
138 
139 static int cs553x_wait_ready(struct cs553x_nand_controller *cs553x,
140 			     unsigned int timeout_ms)
141 {
142 	u8 mask = CS_NAND_CTLR_BUSY | CS_NAND_STS_FLASH_RDY;
143 	u8 status;
144 
145 	return readb_poll_timeout(cs553x->mmio + MM_NAND_STS, status,
146 				  (status & mask) == CS_NAND_STS_FLASH_RDY, 100,
147 				  timeout_ms * 1000);
148 }
149 
150 static int cs553x_exec_instr(struct cs553x_nand_controller *cs553x,
151 			     const struct nand_op_instr *instr)
152 {
153 	unsigned int i;
154 	int ret = 0;
155 
156 	switch (instr->type) {
157 	case NAND_OP_CMD_INSTR:
158 		ret = cs553x_write_ctrl_byte(cs553x, CS_NAND_CTL_CLE,
159 					     instr->ctx.cmd.opcode);
160 		break;
161 
162 	case NAND_OP_ADDR_INSTR:
163 		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
164 			ret = cs553x_write_ctrl_byte(cs553x, CS_NAND_CTL_ALE,
165 						     instr->ctx.addr.addrs[i]);
166 			if (ret)
167 				break;
168 		}
169 		break;
170 
171 	case NAND_OP_DATA_IN_INSTR:
172 		cs553x_data_in(cs553x, instr->ctx.data.buf.in,
173 			       instr->ctx.data.len);
174 		break;
175 
176 	case NAND_OP_DATA_OUT_INSTR:
177 		cs553x_data_out(cs553x, instr->ctx.data.buf.out,
178 				instr->ctx.data.len);
179 		break;
180 
181 	case NAND_OP_WAITRDY_INSTR:
182 		ret = cs553x_wait_ready(cs553x, instr->ctx.waitrdy.timeout_ms);
183 		break;
184 	}
185 
186 	if (instr->delay_ns)
187 		ndelay(instr->delay_ns);
188 
189 	return ret;
190 }
191 
192 static int cs553x_exec_op(struct nand_chip *this,
193 			  const struct nand_operation *op,
194 			  bool check_only)
195 {
196 	struct cs553x_nand_controller *cs553x = to_cs553x(this->controller);
197 	unsigned int i;
198 	int ret;
199 
200 	if (check_only)
201 		return true;
202 
203 	/* De-assert the CE pin */
204 	writeb(0, cs553x->mmio + MM_NAND_CTL);
205 	for (i = 0; i < op->ninstrs; i++) {
206 		ret = cs553x_exec_instr(cs553x, &op->instrs[i]);
207 		if (ret)
208 			break;
209 	}
210 
211 	/* Re-assert the CE pin. */
212 	writeb(CS_NAND_CTL_CE, cs553x->mmio + MM_NAND_CTL);
213 
214 	return ret;
215 }
216 
217 static void cs_enable_hwecc(struct nand_chip *this, int mode)
218 {
219 	struct cs553x_nand_controller *cs553x = to_cs553x(this->controller);
220 
221 	writeb(0x07, cs553x->mmio + MM_NAND_ECC_CTL);
222 }
223 
224 static int cs_calculate_ecc(struct nand_chip *this, const u_char *dat,
225 			    u_char *ecc_code)
226 {
227 	struct cs553x_nand_controller *cs553x = to_cs553x(this->controller);
228 	uint32_t ecc;
229 
230 	ecc = readl(cs553x->mmio + MM_NAND_STS);
231 
232 	ecc_code[1] = ecc >> 8;
233 	ecc_code[0] = ecc >> 16;
234 	ecc_code[2] = ecc >> 24;
235 	return 0;
236 }
237 
238 static struct cs553x_nand_controller *controllers[4];
239 
240 static int cs553x_attach_chip(struct nand_chip *chip)
241 {
242 	if (chip->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST)
243 		return 0;
244 
245 	chip->ecc.size = 256;
246 	chip->ecc.bytes = 3;
247 	chip->ecc.hwctl  = cs_enable_hwecc;
248 	chip->ecc.calculate = cs_calculate_ecc;
249 	chip->ecc.correct  = rawnand_sw_hamming_correct;
250 	chip->ecc.strength = 1;
251 
252 	return 0;
253 }
254 
255 static const struct nand_controller_ops cs553x_nand_controller_ops = {
256 	.exec_op = cs553x_exec_op,
257 	.attach_chip = cs553x_attach_chip,
258 };
259 
260 static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
261 {
262 	struct cs553x_nand_controller *controller;
263 	int err = 0;
264 	struct nand_chip *this;
265 	struct mtd_info *new_mtd;
266 
267 	pr_notice("Probing CS553x NAND controller CS#%d at %sIO 0x%08lx\n",
268 		  cs, mmio ? "MM" : "P", adr);
269 
270 	if (!mmio) {
271 		pr_notice("PIO mode not yet implemented for CS553X NAND controller\n");
272 		return -ENXIO;
273 	}
274 
275 	/* Allocate memory for MTD device structure and private data */
276 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
277 	if (!controller) {
278 		err = -ENOMEM;
279 		goto out;
280 	}
281 
282 	this = &controller->chip;
283 	nand_controller_init(&controller->base);
284 	controller->base.ops = &cs553x_nand_controller_ops;
285 	this->controller = &controller->base;
286 	new_mtd = nand_to_mtd(this);
287 
288 	/* Link the private data with the MTD structure */
289 	new_mtd->owner = THIS_MODULE;
290 
291 	/* map physical address */
292 	controller->mmio = ioremap(adr, 4096);
293 	if (!controller->mmio) {
294 		pr_warn("ioremap cs553x NAND @0x%08lx failed\n", adr);
295 		err = -EIO;
296 		goto out_mtd;
297 	}
298 
299 	/* Enable the following for a flash based bad block table */
300 	this->bbt_options = NAND_BBT_USE_FLASH;
301 
302 	new_mtd->name = kasprintf(GFP_KERNEL, "cs553x_nand_cs%d", cs);
303 	if (!new_mtd->name) {
304 		err = -ENOMEM;
305 		goto out_ior;
306 	}
307 
308 	/* Scan to find existence of the device */
309 	err = nand_scan(this, 1);
310 	if (err)
311 		goto out_free;
312 
313 	controllers[cs] = controller;
314 	goto out;
315 
316 out_free:
317 	kfree(new_mtd->name);
318 out_ior:
319 	iounmap(controller->mmio);
320 out_mtd:
321 	kfree(controller);
322 out:
323 	return err;
324 }
325 
326 static int is_geode(void)
327 {
328 	/* These are the CPUs which will have a CS553[56] companion chip */
329 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
330 	    boot_cpu_data.x86 == 5 &&
331 	    boot_cpu_data.x86_model == 10)
332 		return 1; /* Geode LX */
333 
334 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_NSC ||
335 	     boot_cpu_data.x86_vendor == X86_VENDOR_CYRIX) &&
336 	    boot_cpu_data.x86 == 5 &&
337 	    boot_cpu_data.x86_model == 5)
338 		return 1; /* Geode GX (née GX2) */
339 
340 	return 0;
341 }
342 
343 static int __init cs553x_init(void)
344 {
345 	int err = -ENXIO;
346 	int i;
347 	uint64_t val;
348 
349 	/* If the CPU isn't a Geode GX or LX, abort */
350 	if (!is_geode())
351 		return -ENXIO;
352 
353 	/* If it doesn't have the CS553[56], abort */
354 	rdmsrl(MSR_DIVIL_GLD_CAP, val);
355 	val &= ~0xFFULL;
356 	if (val != CAP_CS5535 && val != CAP_CS5536)
357 		return -ENXIO;
358 
359 	/* If it doesn't have the NAND controller enabled, abort */
360 	rdmsrl(MSR_DIVIL_BALL_OPTS, val);
361 	if (val & PIN_OPT_IDE) {
362 		pr_info("CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS.\n");
363 		return -ENXIO;
364 	}
365 
366 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
367 		rdmsrl(MSR_DIVIL_LBAR_FLSH0 + i, val);
368 
369 		if ((val & (FLSH_LBAR_EN|FLSH_NOR_NAND)) == (FLSH_LBAR_EN|FLSH_NOR_NAND))
370 			err = cs553x_init_one(i, !!(val & FLSH_MEM_IO), val & 0xFFFFFFFF);
371 	}
372 
373 	/* Register all devices together here. This means we can easily hack it to
374 	   do mtdconcat etc. if we want to. */
375 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
376 		if (controllers[i]) {
377 			/* If any devices registered, return success. Else the last error. */
378 			mtd_device_register(nand_to_mtd(&controllers[i]->chip),
379 					    NULL, 0);
380 			err = 0;
381 		}
382 	}
383 
384 	return err;
385 }
386 
387 module_init(cs553x_init);
388 
389 static void __exit cs553x_cleanup(void)
390 {
391 	int i;
392 
393 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
394 		struct cs553x_nand_controller *controller = controllers[i];
395 		struct nand_chip *this = &controller->chip;
396 		struct mtd_info *mtd = nand_to_mtd(this);
397 		int ret;
398 
399 		if (!mtd)
400 			continue;
401 
402 		/* Release resources, unregister device */
403 		ret = mtd_device_unregister(mtd);
404 		WARN_ON(ret);
405 		nand_cleanup(this);
406 		kfree(mtd->name);
407 		controllers[i] = NULL;
408 
409 		/* unmap physical address */
410 		iounmap(controller->mmio);
411 
412 		/* Free the MTD device structure */
413 		kfree(controller);
414 	}
415 }
416 
417 module_exit(cs553x_cleanup);
418 
419 MODULE_LICENSE("GPL");
420 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
421 MODULE_DESCRIPTION("NAND controller driver for AMD CS5535/CS5536 companion chip");
422