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