Root/mips/nand.hhp

1#pypp 0
2// Iris: micro-kernel for a capability-based operating system.
3// mips/nand.hhp: NAND driver functions, split off to be used in two places.
4// The functions are not inline, so this file must be included exactly once per executable that needs it.
5// Copyright 2009 Bas Wijnen <wijnen@debian.org>
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 as published by
9// the Free Software Foundation, either version 3 of the License, or
10// (at your option) any later version.
11//
12// This program is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15// GNU General Public License for more details.
16//
17// You should have received a copy of the GNU General Public License
18// along with this program. If not, see <http://www.gnu.org/licenses/>.
19
20// The following defines are taken from mtd/nand.h in the Linux source.
21// Everything not in the nand datasheet is thrown out.
22
23//#define dbgl() debug ("%s:%d\n", __PRETTY_FUNCTION__, __LINE__)
24#define dbgl()
25
26// Standard NAND flash commands
27#define CMD_READ0 0
28#define CMD_READSTART 0x30
29
30#define CMD_READID 0x90
31
32#define CMD_RESET 0xff
33
34#define CMD_SEQIN 0x80
35#define CMD_PAGEPROG 0x10
36
37#define CMD_ERASE1 0x60
38#define CMD_ERASE2 0xd0
39
40#define CMD_RNDIN 0x85
41
42#define CMD_RNDOUT 5
43#define CMD_RNDOUTSTART 0xe0
44
45#define CMD_STATUS 0x70
46
47// Status bits
48#define STATUS_FAIL 0x01
49#define STATUS_READY 0x40
50#define STATUS_WRITABLE 0x80
51
52static volatile char *command
53static volatile char *address
54static volatile char *data
55
56static unsigned page_bits
57static unsigned redundant_bits
58static unsigned block_bits
59static unsigned size_bits
60static unsigned word_size
61static unsigned ecc_start
62
63static void unbusy ():
64    while !(gpio_get_port (2) & (1 << 30)):
65        DELAY ()
66
67static void addr (unsigned d):
68    unbusy ()
69    *address = d
70
71static void cmd (unsigned d):
72    unbusy ()
73    *command = d
74
75static void wdata (unsigned d):
76    unbusy ()
77    *data = d
78
79static unsigned rdata ():
80    unbusy ()
81    unsigned ret = *data
82    return ret
83
84static void reset ():
85    // Set up.
86    gpio_as_nand ()
87    gpio_as_gpio (2, 1 << 30)
88    gpio_as_input (2, 1 << 30)
89    gpio_enable_pull (2, 1 << 30)
90    EMC_NFCSR = EMC_NFCSR_NFE1 | EMC_NFCSR_NFCE1
91
92    // Reset nand.
93    cmd (CMD_RESET)
94
95    cmd (CMD_READID)
96    addr (0)
97    unsigned d = rdata ()
98    //unsigned maker = d
99    d = rdata ()
100    //unsigned device = d
101    d = rdata ()
102    //unsigned internal_chip_number = 1 << (d & 0x3)
103    //unsigned cell_type = 2 << ((d >> 2) & 0x3)
104    //unsigned simultaneously_programmed_pages = 1 << ((d >> 4) & 0x3)
105    //bool can_interleave_program_between_chips = d & 0x40
106    //bool can_cache_program = d & 0x80
107    d = rdata ()
108    page_bits = 10 + (d & 3)
109    debug ("page bits: %d\n", page_bits)
110    redundant_bits = (d & 4 ? 4 : 3)
111    debug ("redundant bits: %d\n", redundant_bits)
112    block_bits = 16 + ((d >> 4) & 3)
113    debug ("block bits: %d\n", block_bits)
114    word_size = (d & 0x40 ? 16 : 8)
115    debug ("word size: %d\n", word_size)
116    //unsigned serial_access_minimum = (d & 0x80 ? 25 : 50)
117    d = rdata ()
118    unsigned num_planes_bits = d >> 2 & 3
119    unsigned plane_bits = 26 + (d >> 4 & 7)
120    size_bits = plane_bits + num_planes_bits - 3
121    if page_bits == 11:
122        ecc_start = 6
123    else if page_bits == 12:
124        ecc_start = 12
125    else:
126        debug ("unknown nand type; assuming ecc offset to be 6. This is probably wrong!\n")
127        ecc_start = 6
128
129static bool read (unsigned a, char *buffer):
130    unsigned column = a & ((1 << page_bits) - 1)
131    unsigned row = a >> page_bits
132    //debug ("reading %x:", a)
133    // Read oob information first.
134    char error[12]
135    // Spare space (starts at 1 << page_bits)
136    // 0: unused
137    // 2: detect valid data (at least 1 byte == 0 means valid)
138    // 5: unused
139    // 6: 9-byte ecc of 1st 512 bytes
140    // 15: 9-byte ecc of 2nd 512 bytes
141    // 24: 9-byte ecc of 3rd 512 bytes
142    // 33: 9-byte ecc of 4th 512 bytes
143    // 42: unused
144    // 64: end of space
145
146    // For 2 GB nand:
147    // 0-11: unused/bad block markers
148    // 12-89: 8 times 9-byte ecc
149    // 90-127: unused
150    // 128: end of space
151    unsigned col = (1 << page_bits) + ecc_start + 9 * (column >> 9)
152    cmd (CMD_READ0)
153    addr (col)
154    addr (col >> 8)
155    addr (row)
156    addr (row >> 8)
157    addr (row >> 16)
158    cmd (CMD_READSTART)
159    //debug ("parity data:")
160    bool parity_all_ff = true
161    for unsigned t = 0; t < 9; ++t:
162        error[t] = rdata ()
163        if parity_all_ff && (error[t] & 0xff) != 0xff:
164            parity_all_ff = false
165        //debug (" %x", error[t] & 0xff)
166    //debug ("\n")
167    cmd (CMD_RNDOUT)
168    addr (column)
169    addr (column >> 8)
170    cmd (CMD_RNDOUTSTART)
171    EMC_NFINTS = 0
172    EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_DECODING | EMC_NFECR_ERST
173    bool all_ff = true
174    for unsigned t = 0; t < 0x200; ++t:
175        buffer[t] = rdata ()
176        if all_ff && (buffer[t] & 0xff) != 0xff:
177            all_ff = false
178    if !all_ff || !parity_all_ff:
179        for unsigned t = 0; t < 9; ++t:
180            ((volatile char *)&EMC_NFPAR (0))[t] = error[t]
181        EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_DECODING | EMC_NFECR_PRDY
182        while !(EMC_NFINTS & EMC_NFINTS_DECF):
183            DELAY ()
184        unsigned ints = EMC_NFINTS
185        if ints & EMC_NFINTS_UNCOR:
186            debug ("uncorrectable error in nand at %x\n", a)
187            return false
188        unsigned errs = (ints & EMC_NFINTS_ERRCNT_MASK) >> EMC_NFINTS_ERRCNT_BIT
189        for unsigned i = 0; i < errs; ++i:
190            unsigned err = EMC_NFERR (i)
191            unsigned index = (err >> 16) - 1
192            unsigned mask = err & 0x1ff
193            unsigned bit = index * 9
194            unsigned offset= bit & 7
195            unsigned byte = bit / 8
196            debug ("correcting %x on %x+%d\n", mask, byte, offset)
197            unsigned data = buffer[byte] | buffer[byte + 1] << 8
198            data ^= mask << offset
199            buffer[byte] = data
200            buffer[byte + 1] = data >> 8
201    #if 0
202    for unsigned i = 0; i < 0x10; ++i:
203        if (buffer[i] & 0xff) < 0x10:
204            debug (" 0")
205        else:
206            debug (" ")
207        debug ("%x", buffer[i] & 0xff)
208    debug ("\n")
209    #endif
210    return true
211
212static void write (unsigned a, char *buffer):
213    unsigned row = a >> page_bits
214    //debug ("writing: %x/%x\n", a, row)
215    cmd (CMD_SEQIN)
216    addr (0)
217    addr (0)
218    addr (row)
219    addr (row >> 8)
220    addr (row >> 16)
221    char ecc[8][12]
222    for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
223        bool all_ff = true
224        EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_ENCODING | EMC_NFECR_ERST
225        //debug ("writing data from %x\n", (unsigned)buffer + i * 0x200)
226        for unsigned j = 0; j < 0x200; ++j:
227            wdata (buffer[i * 0x200 + j])
228            if all_ff && (buffer[i * 0x200 + j] & 0xff) != 0xff:
229                all_ff = false
230        if !all_ff:
231            while !(EMC_NFINTS & EMC_NFINTS_ENCF):
232                DELAY ()
233            for unsigned t = 0; t < 9; ++t:
234                ecc[i][t] = ((volatile char *)&EMC_NFPAR (0))[t]
235            //debug ("parity for %x:", i * 0x200 + a)
236            //for unsigned t = 0; t < 9; ++t:
237                //debug (" %x", ecc[i][t] & 0xff)
238            //kdebug ("\n")
239        else:
240            for unsigned t = 0; t < 9; ++t:
241                ecc[i][t] = 0xff
242    // Spare space (starts at 1 << page_bits)
243    // 0: unused
244    // 2: detect valid data (at least 1 byte == 0 means valid)
245    // 5: unused
246    // 6: 9-byte ecc of 1st 512 bytes
247    // 15: 9-byte ecc of 2nd 512 bytes
248    // 24: 9-byte ecc of 3rd 512 bytes
249    // 33: 9-byte ecc of 4th 512 bytes
250    // 42: unused
251    // 64: end of space
252
253    // For 2 GB nand:
254    // 0-11: unused/bad block markers
255    // 12-89: 8 times 9-byte ecc
256    // 90-127: unused
257    // 128: end of space
258    for unsigned i = 0; i < ecc_start; ++i:
259        wdata (i == 4 ? 0 : 0xff)
260    for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
261        for unsigned j = 0; j < 9; ++j:
262            wdata (ecc[i][j])
263    cmd (CMD_PAGEPROG)
264    // Wait at least 100 ns.
265    DELAY ()
266    cmd (CMD_READ0)
267    addr (0)
268    addr (0)
269    addr (row)
270    addr (row >> 8)
271    addr (row >> 16)
272    cmd (CMD_READSTART)
273    for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
274        EMC_NFINTS = 0
275        EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_DECODING | EMC_NFECR_ERST
276        for unsigned t = 0; t < 0x200; ++t:
277            unsigned r = rdata () & 0xff
278            if r != (buffer[i * 0x200 + t] & 0xff):
279                debug ("program error at %x: %x != %x\n", i * 0x200 + t, buffer[i * 0x200 + t] & 0xff, r)
280        for unsigned t = 0; t < 9; ++t:
281            ((volatile char *)&EMC_NFPAR (0))[t] = ecc[i][t]
282        EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_DECODING | EMC_NFECR_PRDY
283        while !(EMC_NFINTS & EMC_NFINTS_DECF):
284            DELAY ()
285        unsigned ints = EMC_NFINTS
286        if ints & EMC_NFINTS_UNCOR:
287            debug ("uncorrectable error during verify\n")
288            continue
289        unsigned errs = (ints & EMC_NFINTS_ERRCNT_MASK) >> EMC_NFINTS_ERRCNT_BIT
290        for unsigned i = 0; i < errs; ++i:
291            unsigned err = EMC_NFERR (i)
292            unsigned index = (err >> 16) - 1
293            unsigned mask = err & 0x1ff
294            unsigned bit = index * 9
295            unsigned offset= bit & 7
296            unsigned byte = bit / 8
297            debug ("error detected by parity: %x on %x+%d\n", mask, byte, offset)
298    for unsigned i = 0; i < ecc_start; ++i:
299        if rdata () != (i == 4 ? 0 : 0xff):
300            debug ("incorrect extra data at byte %d\n", i)
301    for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
302        for unsigned j = 0; j < 9; ++j:
303            unsigned r = rdata () & 0xff
304            if r != (ecc[i][j] & 0xff):
305                debug ("ecc doesn't match: %x != %x\n", r, ecc[i][j] & 0xff)
306    //debug ("nand program %x:", a)
307    #if 0
308    for unsigned i = 0; i < 0x10; ++i:
309        if (buffer[i] & 0xff) < 0x10:
310            debug (" 0")
311        else:
312            debug (" ")
313        debug ("%x", buffer[i] & 0xff)
314    debug ("\n")
315    #endif
316
317static void erase (unsigned a):
318    unsigned row = a >> page_bits
319    cmd (CMD_ERASE1)
320    addr (row)
321    addr (row >> 8)
322    addr (row >> 16)
323    cmd (CMD_ERASE2)
324    //debug ("nand erase %d done\n", a)
325

Archive Download this file

Branches:
master



interactive