3 * Gleb Natapov <gnatapov@mrv.com>
4 * Some bits are taken from linux driver writen by adrian@humboldt.co.uk
6 * Hardware I2C driver for MPC107 PCI bridge.
8 * See file CREDITS for list of people who contributed to this
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of
14 * the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
31 #ifdef CONFIG_HARD_I2C
34 #define TIMEOUT (CFG_HZ/4)
36 #define I2C_Addr ((unsigned *)(CFG_EUMB_ADDR + 0x3000))
38 #define I2CADR &I2C_Addr[0]
39 #define I2CFDR &I2C_Addr[1]
40 #define I2CCCR &I2C_Addr[2]
41 #define I2CCSR &I2C_Addr[3]
42 #define I2CCDR &I2C_Addr[4]
44 #define MPC107_CCR_MEN 0x80
45 #define MPC107_CCR_MIEN 0x40
46 #define MPC107_CCR_MSTA 0x20
47 #define MPC107_CCR_MTX 0x10
48 #define MPC107_CCR_TXAK 0x08
49 #define MPC107_CCR_RSTA 0x04
51 #define MPC107_CSR_MCF 0x80
52 #define MPC107_CSR_MAAS 0x40
53 #define MPC107_CSR_MBB 0x20
54 #define MPC107_CSR_MAL 0x10
55 #define MPC107_CSR_SRW 0x04
56 #define MPC107_CSR_MIF 0x02
57 #define MPC107_CSR_RXAK 0x01
62 /* taken from linux include/asm-ppc/io.h */
63 inline unsigned in_le32 (volatile unsigned *addr)
67 __asm__ __volatile__ ("lwbrx %0,0,%1;\n"
69 "isync":"=r" (ret): "r" (addr), "m" (*addr));
73 inline void out_le32 (volatile unsigned *addr, int val)
75 __asm__ __volatile__ ("stwbrx %1,0,%2; eieio":"=m" (*addr):"r" (val),
79 #define writel(val, addr) out_le32(addr, val)
80 #define readl(addr) in_le32(addr)
82 void i2c_init (int speed, int slaveadd)
84 /* stop I2C controller */
87 writel (0x1020, I2CFDR);
88 /* write slave address */
89 writel (slaveadd, I2CADR);
90 /* clear status register */
92 /* start I2C controller */
93 writel (MPC107_CCR_MEN, I2CCCR);
98 static __inline__ int i2c_wait4bus (void)
100 ulong timeval = get_timer (0);
102 while (readl (I2CCSR) & MPC107_CSR_MBB)
103 if (get_timer (timeval) > TIMEOUT)
109 static __inline__ int i2c_wait (int write)
112 ulong timeval = get_timer (0);
115 csr = readl (I2CCSR);
117 if (!(csr & MPC107_CSR_MIF))
120 writel (0x0, I2CCSR);
122 if (csr & MPC107_CSR_MAL) {
124 printf ("i2c_wait: MAL\n");
129 if (!(csr & MPC107_CSR_MCF)) {
131 printf ("i2c_wait: unfinished\n");
136 if (write == I2C_WRITE && (csr & MPC107_CSR_RXAK)) {
138 printf ("i2c_wait: No RXACK\n");
144 } while (get_timer (timeval) < TIMEOUT);
147 printf ("i2c_wait: timed out\n");
152 static __inline__ int i2c_write_addr (u8 dev, u8 dir, int rsta)
154 writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX |
155 (rsta ? MPC107_CCR_RSTA : 0), I2CCCR);
157 writel ((dev << 1) | dir, I2CCDR);
159 if (i2c_wait (I2C_WRITE) < 0)
165 static __inline__ int __i2c_write (u8 * data, int length)
169 writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX, I2CCCR);
171 for (i = 0; i < length; i++) {
172 writel (data[i], I2CCDR);
174 if (i2c_wait (I2C_WRITE) < 0)
181 static __inline__ int __i2c_read (u8 * data, int length)
185 writel (MPC107_CCR_MEN | MPC107_CCR_MSTA |
186 ((length == 1) ? MPC107_CCR_TXAK : 0), I2CCCR);
191 for (i = 0; i < length; i++) {
192 if (i2c_wait (I2C_READ) < 0)
195 /* Generate ack on last next to last byte */
197 writel (MPC107_CCR_MEN | MPC107_CCR_MSTA |
198 MPC107_CCR_TXAK, I2CCCR);
200 /* Generate stop on last byte */
202 writel (MPC107_CCR_MEN | MPC107_CCR_TXAK, I2CCCR);
204 data[i] = readl (I2CCDR);
210 int i2c_read (u8 dev, uint addr, int alen, u8 * data, int length)
213 u8 *a = (u8 *) & addr;
215 if (i2c_wait4bus () < 0)
218 if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
221 if (__i2c_write (&a[4 - alen], alen) != alen)
224 if (i2c_write_addr (dev, I2C_READ, 1) == 0)
227 i = __i2c_read (data, length);
230 writel (MPC107_CCR_MEN, I2CCCR);
232 return !(i == length);
235 int i2c_write (u8 dev, uint addr, int alen, u8 * data, int length)
238 u8 *a = (u8 *) & addr;
240 if (i2c_wait4bus () < 0)
243 if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
246 if (__i2c_write (&a[4 - alen], alen) != alen)
249 i = __i2c_write (data, length);
252 writel (MPC107_CCR_MEN, I2CCCR);
254 return !(i == length);
257 int i2c_probe (uchar chip)
262 * Try to read the first location of the chip. The underlying
263 * driver doesn't appear to support sending just the chip address
264 * and looking for an <ACK> back.
267 return i2c_read (chip, 0, 1, (uchar *) &tmp, 1);
270 uchar i2c_reg_read (uchar i2c_addr, uchar reg)
274 i2c_read (i2c_addr, reg, 1, buf, 1);
279 void i2c_reg_write (uchar i2c_addr, uchar reg, uchar val)
281 i2c_write (i2c_addr, reg, 1, &val, 1);
284 #endif /* CONFIG_HARD_I2C */