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
98static 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
110static 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
122static 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
128static 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
140static 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
153static 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
162static 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
170static 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
184static struct mtd_info *cs553x_mtd[4];
185
186static 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	new_mtd->name = kasprintf(GFP_KERNEL, "cs553x_nand_cs%d", cs);
241	if (!new_mtd->name) {
242		err = -ENOMEM;
243		goto out_ior;
244	}
245
246	/* Scan to find existence of the device */
247	if (nand_scan(new_mtd, 1)) {
248		err = -ENXIO;
249		goto out_free;
250	}
251
252	cs553x_mtd[cs] = new_mtd;
253	goto out;
254
255out_free:
256	kfree(new_mtd->name);
257out_ior:
258	iounmap(this->IO_ADDR_R);
259out_mtd:
260	kfree(new_mtd);
261out:
262	return err;
263}
264
265static int is_geode(void)
266{
267	/* These are the CPUs which will have a CS553[56] companion chip */
268	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
269	    boot_cpu_data.x86 == 5 &&
270	    boot_cpu_data.x86_model == 10)
271		return 1; /* Geode LX */
272
273	if ((boot_cpu_data.x86_vendor == X86_VENDOR_NSC ||
274	     boot_cpu_data.x86_vendor == X86_VENDOR_CYRIX) &&
275	    boot_cpu_data.x86 == 5 &&
276	    boot_cpu_data.x86_model == 5)
277		return 1; /* Geode GX (n��e GX2) */
278
279	return 0;
280}
281
282static int __init cs553x_init(void)
283{
284	int err = -ENXIO;
285	int i;
286	uint64_t val;
287
288	/* If the CPU isn't a Geode GX or LX, abort */
289	if (!is_geode())
290		return -ENXIO;
291
292	/* If it doesn't have the CS553[56], abort */
293	rdmsrl(MSR_DIVIL_GLD_CAP, val);
294	val &= ~0xFFULL;
295	if (val != CAP_CS5535 && val != CAP_CS5536)
296		return -ENXIO;
297
298	/* If it doesn't have the NAND controller enabled, abort */
299	rdmsrl(MSR_DIVIL_BALL_OPTS, val);
300	if (val & PIN_OPT_IDE) {
301		printk(KERN_INFO "CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS.\n");
302		return -ENXIO;
303	}
304
305	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
306		rdmsrl(MSR_DIVIL_LBAR_FLSH0 + i, val);
307
308		if ((val & (FLSH_LBAR_EN|FLSH_NOR_NAND)) == (FLSH_LBAR_EN|FLSH_NOR_NAND))
309			err = cs553x_init_one(i, !!(val & FLSH_MEM_IO), val & 0xFFFFFFFF);
310	}
311
312	/* Register all devices together here. This means we can easily hack it to
313	   do mtdconcat etc. if we want to. */
314	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
315		if (cs553x_mtd[i]) {
316			/* If any devices registered, return success. Else the last error. */
317			mtd_device_parse_register(cs553x_mtd[i], NULL, NULL,
318						  NULL, 0);
319			err = 0;
320		}
321	}
322
323	return err;
324}
325
326module_init(cs553x_init);
327
328static void __exit cs553x_cleanup(void)
329{
330	int i;
331
332	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
333		struct mtd_info *mtd = cs553x_mtd[i];
334		struct nand_chip *this;
335		void __iomem *mmio_base;
336
337		if (!mtd)
338			continue;
339
340		this = cs553x_mtd[i]->priv;
341		mmio_base = this->IO_ADDR_R;
342
343		/* Release resources, unregister device */
344		nand_release(cs553x_mtd[i]);
345		kfree(cs553x_mtd[i]->name);
346		cs553x_mtd[i] = NULL;
347
348		/* unmap physical address */
349		iounmap(mmio_base);
350
351		/* Free the MTD device structure */
352		kfree(mtd);
353	}
354}
355
356module_exit(cs553x_cleanup);
357
358MODULE_LICENSE("GPL");
359MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
360MODULE_DESCRIPTION("NAND controller driver for AMD CS5535/CS5536 companion chip");
361