xref: /openbmc/linux/drivers/mtd/nand/raw/cs553x_nand.c (revision 3213486f)
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 nand_chip *this, u_char *buf, int len)
97 {
98 	while (unlikely(len > 0x800)) {
99 		memcpy_fromio(buf, this->legacy.IO_ADDR_R, 0x800);
100 		buf += 0x800;
101 		len -= 0x800;
102 	}
103 	memcpy_fromio(buf, this->legacy.IO_ADDR_R, len);
104 }
105 
106 static void cs553x_write_buf(struct nand_chip *this, const u_char *buf, int len)
107 {
108 	while (unlikely(len > 0x800)) {
109 		memcpy_toio(this->legacy.IO_ADDR_R, buf, 0x800);
110 		buf += 0x800;
111 		len -= 0x800;
112 	}
113 	memcpy_toio(this->legacy.IO_ADDR_R, buf, len);
114 }
115 
116 static unsigned char cs553x_read_byte(struct nand_chip *this)
117 {
118 	return readb(this->legacy.IO_ADDR_R);
119 }
120 
121 static void cs553x_write_byte(struct nand_chip *this, u_char byte)
122 {
123 	int i = 100000;
124 
125 	while (i && readb(this->legacy.IO_ADDR_R + MM_NAND_STS) & CS_NAND_CTLR_BUSY) {
126 		udelay(1);
127 		i--;
128 	}
129 	writeb(byte, this->legacy.IO_ADDR_W + 0x801);
130 }
131 
132 static void cs553x_hwcontrol(struct nand_chip *this, int cmd,
133 			     unsigned int ctrl)
134 {
135 	void __iomem *mmio_base = this->legacy.IO_ADDR_R;
136 	if (ctrl & NAND_CTRL_CHANGE) {
137 		unsigned char ctl = (ctrl & ~NAND_CTRL_CHANGE ) ^ 0x01;
138 		writeb(ctl, mmio_base + MM_NAND_CTL);
139 	}
140 	if (cmd != NAND_CMD_NONE)
141 		cs553x_write_byte(this, cmd);
142 }
143 
144 static int cs553x_device_ready(struct nand_chip *this)
145 {
146 	void __iomem *mmio_base = this->legacy.IO_ADDR_R;
147 	unsigned char foo = readb(mmio_base + MM_NAND_STS);
148 
149 	return (foo & CS_NAND_STS_FLASH_RDY) && !(foo & CS_NAND_CTLR_BUSY);
150 }
151 
152 static void cs_enable_hwecc(struct nand_chip *this, int mode)
153 {
154 	void __iomem *mmio_base = this->legacy.IO_ADDR_R;
155 
156 	writeb(0x07, mmio_base + MM_NAND_ECC_CTL);
157 }
158 
159 static int cs_calculate_ecc(struct nand_chip *this, const u_char *dat,
160 			    u_char *ecc_code)
161 {
162 	uint32_t ecc;
163 	void __iomem *mmio_base = this->legacy.IO_ADDR_R;
164 
165 	ecc = readl(mmio_base + MM_NAND_STS);
166 
167 	ecc_code[1] = ecc >> 8;
168 	ecc_code[0] = ecc >> 16;
169 	ecc_code[2] = ecc >> 24;
170 	return 0;
171 }
172 
173 static struct mtd_info *cs553x_mtd[4];
174 
175 static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
176 {
177 	int err = 0;
178 	struct nand_chip *this;
179 	struct mtd_info *new_mtd;
180 
181 	pr_notice("Probing CS553x NAND controller CS#%d at %sIO 0x%08lx\n",
182 		  cs, mmio ? "MM" : "P", adr);
183 
184 	if (!mmio) {
185 		pr_notice("PIO mode not yet implemented for CS553X NAND controller\n");
186 		return -ENXIO;
187 	}
188 
189 	/* Allocate memory for MTD device structure and private data */
190 	this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
191 	if (!this) {
192 		err = -ENOMEM;
193 		goto out;
194 	}
195 
196 	new_mtd = nand_to_mtd(this);
197 
198 	/* Link the private data with the MTD structure */
199 	new_mtd->owner = THIS_MODULE;
200 
201 	/* map physical address */
202 	this->legacy.IO_ADDR_R = this->legacy.IO_ADDR_W = ioremap(adr, 4096);
203 	if (!this->legacy.IO_ADDR_R) {
204 		pr_warn("ioremap cs553x NAND @0x%08lx failed\n", adr);
205 		err = -EIO;
206 		goto out_mtd;
207 	}
208 
209 	this->legacy.cmd_ctrl = cs553x_hwcontrol;
210 	this->legacy.dev_ready = cs553x_device_ready;
211 	this->legacy.read_byte = cs553x_read_byte;
212 	this->legacy.read_buf = cs553x_read_buf;
213 	this->legacy.write_buf = cs553x_write_buf;
214 
215 	this->legacy.chip_delay = 0;
216 
217 	this->ecc.mode = NAND_ECC_HW;
218 	this->ecc.size = 256;
219 	this->ecc.bytes = 3;
220 	this->ecc.hwctl  = cs_enable_hwecc;
221 	this->ecc.calculate = cs_calculate_ecc;
222 	this->ecc.correct  = nand_correct_data;
223 	this->ecc.strength = 1;
224 
225 	/* Enable the following for a flash based bad block table */
226 	this->bbt_options = NAND_BBT_USE_FLASH;
227 
228 	new_mtd->name = kasprintf(GFP_KERNEL, "cs553x_nand_cs%d", cs);
229 	if (!new_mtd->name) {
230 		err = -ENOMEM;
231 		goto out_ior;
232 	}
233 
234 	/* Scan to find existence of the device */
235 	err = nand_scan(this, 1);
236 	if (err)
237 		goto out_free;
238 
239 	cs553x_mtd[cs] = new_mtd;
240 	goto out;
241 
242 out_free:
243 	kfree(new_mtd->name);
244 out_ior:
245 	iounmap(this->legacy.IO_ADDR_R);
246 out_mtd:
247 	kfree(this);
248 out:
249 	return err;
250 }
251 
252 static int is_geode(void)
253 {
254 	/* These are the CPUs which will have a CS553[56] companion chip */
255 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
256 	    boot_cpu_data.x86 == 5 &&
257 	    boot_cpu_data.x86_model == 10)
258 		return 1; /* Geode LX */
259 
260 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_NSC ||
261 	     boot_cpu_data.x86_vendor == X86_VENDOR_CYRIX) &&
262 	    boot_cpu_data.x86 == 5 &&
263 	    boot_cpu_data.x86_model == 5)
264 		return 1; /* Geode GX (née GX2) */
265 
266 	return 0;
267 }
268 
269 static int __init cs553x_init(void)
270 {
271 	int err = -ENXIO;
272 	int i;
273 	uint64_t val;
274 
275 	/* If the CPU isn't a Geode GX or LX, abort */
276 	if (!is_geode())
277 		return -ENXIO;
278 
279 	/* If it doesn't have the CS553[56], abort */
280 	rdmsrl(MSR_DIVIL_GLD_CAP, val);
281 	val &= ~0xFFULL;
282 	if (val != CAP_CS5535 && val != CAP_CS5536)
283 		return -ENXIO;
284 
285 	/* If it doesn't have the NAND controller enabled, abort */
286 	rdmsrl(MSR_DIVIL_BALL_OPTS, val);
287 	if (val & PIN_OPT_IDE) {
288 		pr_info("CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS.\n");
289 		return -ENXIO;
290 	}
291 
292 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
293 		rdmsrl(MSR_DIVIL_LBAR_FLSH0 + i, val);
294 
295 		if ((val & (FLSH_LBAR_EN|FLSH_NOR_NAND)) == (FLSH_LBAR_EN|FLSH_NOR_NAND))
296 			err = cs553x_init_one(i, !!(val & FLSH_MEM_IO), val & 0xFFFFFFFF);
297 	}
298 
299 	/* Register all devices together here. This means we can easily hack it to
300 	   do mtdconcat etc. if we want to. */
301 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
302 		if (cs553x_mtd[i]) {
303 			/* If any devices registered, return success. Else the last error. */
304 			mtd_device_register(cs553x_mtd[i], NULL, 0);
305 			err = 0;
306 		}
307 	}
308 
309 	return err;
310 }
311 
312 module_init(cs553x_init);
313 
314 static void __exit cs553x_cleanup(void)
315 {
316 	int i;
317 
318 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
319 		struct mtd_info *mtd = cs553x_mtd[i];
320 		struct nand_chip *this;
321 		void __iomem *mmio_base;
322 
323 		if (!mtd)
324 			continue;
325 
326 		this = mtd_to_nand(mtd);
327 		mmio_base = this->legacy.IO_ADDR_R;
328 
329 		/* Release resources, unregister device */
330 		nand_release(this);
331 		kfree(mtd->name);
332 		cs553x_mtd[i] = NULL;
333 
334 		/* unmap physical address */
335 		iounmap(mmio_base);
336 
337 		/* Free the MTD device structure */
338 		kfree(this);
339 	}
340 }
341 
342 module_exit(cs553x_cleanup);
343 
344 MODULE_LICENSE("GPL");
345 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
346 MODULE_DESCRIPTION("NAND controller driver for AMD CS5535/CS5536 companion chip");
347