xref: /openbmc/linux/drivers/mtd/nand/raw/cs553x_nand.c (revision 8bd1369b)
1 /*
2  * (C) 2005, 2006 Red Hat Inc.
3  *
4  * Author: David Woodhouse <dwmw2@infradead.org>
5  *	   Tom Sylla <tom.sylla@amd.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  *  Overview:
12  *   This is a device driver for the NAND flash controller found on
13  *   the AMD CS5535/CS5536 companion chipsets for the Geode processor.
14  *   mtd-id for command line partitioning is cs553x_nand_cs[0-3]
15  *   where 0-3 reflects the chip select for NAND.
16  *
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/slab.h>
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/delay.h>
24 #include <linux/mtd/mtd.h>
25 #include <linux/mtd/rawnand.h>
26 #include <linux/mtd/nand_ecc.h>
27 #include <linux/mtd/partitions.h>
28 
29 #include <asm/msr.h>
30 #include <asm/io.h>
31 
32 #define NR_CS553X_CONTROLLERS	4
33 
34 #define MSR_DIVIL_GLD_CAP	0x51400000	/* DIVIL capabilitiies */
35 #define CAP_CS5535		0x2df000ULL
36 #define CAP_CS5536		0x5df500ULL
37 
38 /* NAND Timing MSRs */
39 #define MSR_NANDF_DATA		0x5140001b	/* NAND Flash Data Timing MSR */
40 #define MSR_NANDF_CTL		0x5140001c	/* NAND Flash Control Timing */
41 #define MSR_NANDF_RSVD		0x5140001d	/* Reserved */
42 
43 /* NAND BAR MSRs */
44 #define MSR_DIVIL_LBAR_FLSH0	0x51400010	/* Flash Chip Select 0 */
45 #define MSR_DIVIL_LBAR_FLSH1	0x51400011	/* Flash Chip Select 1 */
46 #define MSR_DIVIL_LBAR_FLSH2	0x51400012	/* Flash Chip Select 2 */
47 #define MSR_DIVIL_LBAR_FLSH3	0x51400013	/* Flash Chip Select 3 */
48 	/* Each made up of... */
49 #define FLSH_LBAR_EN		(1ULL<<32)
50 #define FLSH_NOR_NAND		(1ULL<<33)	/* 1 for NAND */
51 #define FLSH_MEM_IO		(1ULL<<34)	/* 1 for MMIO */
52 	/* I/O BARs have BASE_ADDR in bits 15:4, IO_MASK in 47:36 */
53 	/* MMIO BARs have BASE_ADDR in bits 31:12, MEM_MASK in 63:44 */
54 
55 /* Pin function selection MSR (IDE vs. flash on the IDE pins) */
56 #define MSR_DIVIL_BALL_OPTS	0x51400015
57 #define PIN_OPT_IDE		(1<<0)	/* 0 for flash, 1 for IDE */
58 
59 /* Registers within the NAND flash controller BAR -- memory mapped */
60 #define MM_NAND_DATA		0x00	/* 0 to 0x7ff, in fact */
61 #define MM_NAND_CTL		0x800	/* Any even address 0x800-0x80e */
62 #define MM_NAND_IO		0x801	/* Any odd address 0x801-0x80f */
63 #define MM_NAND_STS		0x810
64 #define MM_NAND_ECC_LSB		0x811
65 #define MM_NAND_ECC_MSB		0x812
66 #define MM_NAND_ECC_COL		0x813
67 #define MM_NAND_LAC		0x814
68 #define MM_NAND_ECC_CTL		0x815
69 
70 /* Registers within the NAND flash controller BAR -- I/O mapped */
71 #define IO_NAND_DATA		0x00	/* 0 to 3, in fact */
72 #define IO_NAND_CTL		0x04
73 #define IO_NAND_IO		0x05
74 #define IO_NAND_STS		0x06
75 #define IO_NAND_ECC_CTL		0x08
76 #define IO_NAND_ECC_LSB		0x09
77 #define IO_NAND_ECC_MSB		0x0a
78 #define IO_NAND_ECC_COL		0x0b
79 #define IO_NAND_LAC		0x0c
80 
81 #define CS_NAND_CTL_DIST_EN	(1<<4)	/* Enable NAND Distract interrupt */
82 #define CS_NAND_CTL_RDY_INT_MASK	(1<<3)	/* Enable RDY/BUSY# interrupt */
83 #define CS_NAND_CTL_ALE		(1<<2)
84 #define CS_NAND_CTL_CLE		(1<<1)
85 #define CS_NAND_CTL_CE		(1<<0)	/* Keep low; 1 to reset */
86 
87 #define CS_NAND_STS_FLASH_RDY	(1<<3)
88 #define CS_NAND_CTLR_BUSY	(1<<2)
89 #define CS_NAND_CMD_COMP	(1<<1)
90 #define CS_NAND_DIST_ST		(1<<0)
91 
92 #define CS_NAND_ECC_PARITY	(1<<2)
93 #define CS_NAND_ECC_CLRECC	(1<<1)
94 #define CS_NAND_ECC_ENECC	(1<<0)
95 
96 static void cs553x_read_buf(struct mtd_info *mtd, u_char *buf, int len)
97 {
98 	struct nand_chip *this = mtd_to_nand(mtd);
99 
100 	while (unlikely(len > 0x800)) {
101 		memcpy_fromio(buf, this->IO_ADDR_R, 0x800);
102 		buf += 0x800;
103 		len -= 0x800;
104 	}
105 	memcpy_fromio(buf, this->IO_ADDR_R, len);
106 }
107 
108 static void cs553x_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
109 {
110 	struct nand_chip *this = mtd_to_nand(mtd);
111 
112 	while (unlikely(len > 0x800)) {
113 		memcpy_toio(this->IO_ADDR_R, buf, 0x800);
114 		buf += 0x800;
115 		len -= 0x800;
116 	}
117 	memcpy_toio(this->IO_ADDR_R, buf, len);
118 }
119 
120 static unsigned char cs553x_read_byte(struct mtd_info *mtd)
121 {
122 	struct nand_chip *this = mtd_to_nand(mtd);
123 	return readb(this->IO_ADDR_R);
124 }
125 
126 static void cs553x_write_byte(struct mtd_info *mtd, u_char byte)
127 {
128 	struct nand_chip *this = mtd_to_nand(mtd);
129 	int i = 100000;
130 
131 	while (i && readb(this->IO_ADDR_R + MM_NAND_STS) & CS_NAND_CTLR_BUSY) {
132 		udelay(1);
133 		i--;
134 	}
135 	writeb(byte, this->IO_ADDR_W + 0x801);
136 }
137 
138 static void cs553x_hwcontrol(struct mtd_info *mtd, int cmd,
139 			     unsigned int ctrl)
140 {
141 	struct nand_chip *this = mtd_to_nand(mtd);
142 	void __iomem *mmio_base = this->IO_ADDR_R;
143 	if (ctrl & NAND_CTRL_CHANGE) {
144 		unsigned char ctl = (ctrl & ~NAND_CTRL_CHANGE ) ^ 0x01;
145 		writeb(ctl, mmio_base + MM_NAND_CTL);
146 	}
147 	if (cmd != NAND_CMD_NONE)
148 		cs553x_write_byte(mtd, cmd);
149 }
150 
151 static int cs553x_device_ready(struct mtd_info *mtd)
152 {
153 	struct nand_chip *this = mtd_to_nand(mtd);
154 	void __iomem *mmio_base = this->IO_ADDR_R;
155 	unsigned char foo = readb(mmio_base + MM_NAND_STS);
156 
157 	return (foo & CS_NAND_STS_FLASH_RDY) && !(foo & CS_NAND_CTLR_BUSY);
158 }
159 
160 static void cs_enable_hwecc(struct mtd_info *mtd, int mode)
161 {
162 	struct nand_chip *this = mtd_to_nand(mtd);
163 	void __iomem *mmio_base = this->IO_ADDR_R;
164 
165 	writeb(0x07, mmio_base + MM_NAND_ECC_CTL);
166 }
167 
168 static int cs_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code)
169 {
170 	uint32_t ecc;
171 	struct nand_chip *this = mtd_to_nand(mtd);
172 	void __iomem *mmio_base = this->IO_ADDR_R;
173 
174 	ecc = readl(mmio_base + MM_NAND_STS);
175 
176 	ecc_code[1] = ecc >> 8;
177 	ecc_code[0] = ecc >> 16;
178 	ecc_code[2] = ecc >> 24;
179 	return 0;
180 }
181 
182 static struct mtd_info *cs553x_mtd[4];
183 
184 static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
185 {
186 	int err = 0;
187 	struct nand_chip *this;
188 	struct mtd_info *new_mtd;
189 
190 	pr_notice("Probing CS553x NAND controller CS#%d at %sIO 0x%08lx\n",
191 		  cs, mmio ? "MM" : "P", adr);
192 
193 	if (!mmio) {
194 		pr_notice("PIO mode not yet implemented for CS553X NAND controller\n");
195 		return -ENXIO;
196 	}
197 
198 	/* Allocate memory for MTD device structure and private data */
199 	this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
200 	if (!this) {
201 		err = -ENOMEM;
202 		goto out;
203 	}
204 
205 	new_mtd = nand_to_mtd(this);
206 
207 	/* Link the private data with the MTD structure */
208 	new_mtd->owner = THIS_MODULE;
209 
210 	/* map physical address */
211 	this->IO_ADDR_R = this->IO_ADDR_W = ioremap(adr, 4096);
212 	if (!this->IO_ADDR_R) {
213 		pr_warn("ioremap cs553x NAND @0x%08lx failed\n", adr);
214 		err = -EIO;
215 		goto out_mtd;
216 	}
217 
218 	this->cmd_ctrl = cs553x_hwcontrol;
219 	this->dev_ready = cs553x_device_ready;
220 	this->read_byte = cs553x_read_byte;
221 	this->read_buf = cs553x_read_buf;
222 	this->write_buf = cs553x_write_buf;
223 
224 	this->chip_delay = 0;
225 
226 	this->ecc.mode = NAND_ECC_HW;
227 	this->ecc.size = 256;
228 	this->ecc.bytes = 3;
229 	this->ecc.hwctl  = cs_enable_hwecc;
230 	this->ecc.calculate = cs_calculate_ecc;
231 	this->ecc.correct  = nand_correct_data;
232 	this->ecc.strength = 1;
233 
234 	/* Enable the following for a flash based bad block table */
235 	this->bbt_options = NAND_BBT_USE_FLASH;
236 
237 	new_mtd->name = kasprintf(GFP_KERNEL, "cs553x_nand_cs%d", cs);
238 	if (!new_mtd->name) {
239 		err = -ENOMEM;
240 		goto out_ior;
241 	}
242 
243 	/* Scan to find existence of the device */
244 	err = nand_scan(new_mtd, 1);
245 	if (err)
246 		goto out_free;
247 
248 	cs553x_mtd[cs] = new_mtd;
249 	goto out;
250 
251 out_free:
252 	kfree(new_mtd->name);
253 out_ior:
254 	iounmap(this->IO_ADDR_R);
255 out_mtd:
256 	kfree(this);
257 out:
258 	return err;
259 }
260 
261 static int is_geode(void)
262 {
263 	/* These are the CPUs which will have a CS553[56] companion chip */
264 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
265 	    boot_cpu_data.x86 == 5 &&
266 	    boot_cpu_data.x86_model == 10)
267 		return 1; /* Geode LX */
268 
269 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_NSC ||
270 	     boot_cpu_data.x86_vendor == X86_VENDOR_CYRIX) &&
271 	    boot_cpu_data.x86 == 5 &&
272 	    boot_cpu_data.x86_model == 5)
273 		return 1; /* Geode GX (née GX2) */
274 
275 	return 0;
276 }
277 
278 static int __init cs553x_init(void)
279 {
280 	int err = -ENXIO;
281 	int i;
282 	uint64_t val;
283 
284 	/* If the CPU isn't a Geode GX or LX, abort */
285 	if (!is_geode())
286 		return -ENXIO;
287 
288 	/* If it doesn't have the CS553[56], abort */
289 	rdmsrl(MSR_DIVIL_GLD_CAP, val);
290 	val &= ~0xFFULL;
291 	if (val != CAP_CS5535 && val != CAP_CS5536)
292 		return -ENXIO;
293 
294 	/* If it doesn't have the NAND controller enabled, abort */
295 	rdmsrl(MSR_DIVIL_BALL_OPTS, val);
296 	if (val & PIN_OPT_IDE) {
297 		pr_info("CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS.\n");
298 		return -ENXIO;
299 	}
300 
301 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
302 		rdmsrl(MSR_DIVIL_LBAR_FLSH0 + i, val);
303 
304 		if ((val & (FLSH_LBAR_EN|FLSH_NOR_NAND)) == (FLSH_LBAR_EN|FLSH_NOR_NAND))
305 			err = cs553x_init_one(i, !!(val & FLSH_MEM_IO), val & 0xFFFFFFFF);
306 	}
307 
308 	/* Register all devices together here. This means we can easily hack it to
309 	   do mtdconcat etc. if we want to. */
310 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
311 		if (cs553x_mtd[i]) {
312 			/* If any devices registered, return success. Else the last error. */
313 			mtd_device_parse_register(cs553x_mtd[i], NULL, NULL,
314 						  NULL, 0);
315 			err = 0;
316 		}
317 	}
318 
319 	return err;
320 }
321 
322 module_init(cs553x_init);
323 
324 static void __exit cs553x_cleanup(void)
325 {
326 	int i;
327 
328 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
329 		struct mtd_info *mtd = cs553x_mtd[i];
330 		struct nand_chip *this;
331 		void __iomem *mmio_base;
332 
333 		if (!mtd)
334 			continue;
335 
336 		this = mtd_to_nand(mtd);
337 		mmio_base = this->IO_ADDR_R;
338 
339 		/* Release resources, unregister device */
340 		nand_release(mtd);
341 		kfree(mtd->name);
342 		cs553x_mtd[i] = NULL;
343 
344 		/* unmap physical address */
345 		iounmap(mmio_base);
346 
347 		/* Free the MTD device structure */
348 		kfree(this);
349 	}
350 }
351 
352 module_exit(cs553x_cleanup);
353 
354 MODULE_LICENSE("GPL");
355 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
356 MODULE_DESCRIPTION("NAND controller driver for AMD CS5535/CS5536 companion chip");
357