2 * i2c driver for Freescale mx31
4 * (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
28 #if defined(CONFIG_HARD_I2C)
30 #if defined(CONFIG_MX31)
31 #include <asm/arch/mx31.h>
32 #include <asm/arch/mx31-regs.h>
34 #include <asm/arch/imx-regs.h>
35 #include <asm/arch/clock.h>
44 #define I2CR_IEN (1 << 7)
45 #define I2CR_IIEN (1 << 6)
46 #define I2CR_MSTA (1 << 5)
47 #define I2CR_MTX (1 << 4)
48 #define I2CR_TX_NO_AK (1 << 3)
49 #define I2CR_RSTA (1 << 2)
51 #define I2SR_ICF (1 << 7)
52 #define I2SR_IBB (1 << 5)
53 #define I2SR_IIF (1 << 1)
54 #define I2SR_RX_NO_AK (1 << 0)
56 #if defined(CONFIG_SYS_I2C_MX31_PORT1)
57 #define I2C_BASE 0x43f80000
58 #define I2C_CLK_OFFSET 26
59 #elif defined (CONFIG_SYS_I2C_MX31_PORT2)
60 #define I2C_BASE 0x43f98000
61 #define I2C_CLK_OFFSET 28
62 #elif defined (CONFIG_SYS_I2C_MX31_PORT3)
63 #define I2C_BASE 0x43f84000
64 #define I2C_CLK_OFFSET 30
65 #elif defined(CONFIG_SYS_I2C_MX53_PORT1)
66 #define I2C_BASE I2C1_BASE_ADDR
67 #elif defined(CONFIG_SYS_I2C_MX53_PORT2)
68 #define I2C_BASE I2C2_BASE_ADDR
69 #elif defined(CONFIG_SYS_I2C_MX35_PORT1)
70 #define I2C_BASE I2C_BASE_ADDR
72 #error "define CONFIG_SYS_I2C_MX<Processor>_PORTx to use the mx I2C driver"
76 #define DPRINTF(args...) printf(args)
78 #define DPRINTF(args...)
81 static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144,
82 160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960,
83 1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840};
85 static inline void i2c_reset(void)
87 writew(0, I2C_BASE + I2CR); /* Reset module */
88 writew(0, I2C_BASE + I2SR);
89 writew(I2CR_IEN, I2C_BASE + I2CR);
92 void i2c_init(int speed, int unused)
97 #if defined(CONFIG_MX31)
98 struct clock_control_regs *sc_regs =
99 (struct clock_control_regs *)CCM_BASE;
101 freq = mx31_get_ipg_clk();
102 /* start the required I2C clock */
103 writel(readl(&sc_regs->cgr0) | (3 << I2C_CLK_OFFSET),
106 freq = mxc_get_clock(MXC_IPG_PERCLK);
109 for (i = 0; i < 0x1f; i++)
110 if (freq / div[i] <= speed)
113 debug("%s: speed: %d\n", __func__, speed);
115 writew(i, I2C_BASE + IFDR);
119 static int wait_busy(void)
123 while (!(readw(I2C_BASE + I2SR) & I2SR_IIF) && --timeout)
125 writew(0, I2C_BASE + I2SR); /* clear interrupt */
130 static int tx_byte(u8 byte)
132 writew(byte, I2C_BASE + I2DR);
134 if (!wait_busy() || readw(I2C_BASE + I2SR) & I2SR_RX_NO_AK)
139 static int rx_byte(void)
144 return readw(I2C_BASE + I2DR);
147 int i2c_probe(uchar chip)
151 writew(0, I2C_BASE + I2CR); /* Reset module */
152 writew(I2CR_IEN, I2C_BASE + I2CR);
154 writew(I2CR_IEN | I2CR_MSTA | I2CR_MTX, I2C_BASE + I2CR);
155 ret = tx_byte(chip << 1);
156 writew(I2CR_IEN | I2CR_MTX, I2C_BASE + I2CR);
161 static int i2c_addr(uchar chip, uint addr, int alen)
163 writew(0, I2C_BASE + I2SR);
164 writew(I2CR_IEN | I2CR_MSTA | I2CR_MTX, I2C_BASE + I2CR);
166 if (tx_byte(chip << 1))
170 if (tx_byte((addr >> (alen * 8)) & 0xff))
175 int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
180 debug("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",
181 __func__, chip, addr, alen, len);
183 if (i2c_addr(chip, addr, alen)) {
184 printf("i2c_addr failed\n");
188 writew(I2CR_IEN | I2CR_MSTA | I2CR_MTX | I2CR_RSTA, I2C_BASE + I2CR);
190 if (tx_byte(chip << 1 | 1))
193 writew(I2CR_IEN | I2CR_MSTA |
194 ((len == 1) ? I2CR_TX_NO_AK : 0),
197 ret = readw(I2C_BASE + I2DR);
200 if ((ret = rx_byte()) < 0)
204 writew(I2CR_IEN | I2CR_MSTA |
211 writew(I2CR_IEN, I2C_BASE + I2CR);
213 while (readw(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
219 int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
221 int timeout = I2C_MAX_TIMEOUT;
222 debug("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",
223 __func__, chip, addr, alen, len);
225 if (i2c_addr(chip, addr, alen))
232 writew(I2CR_IEN, I2C_BASE + I2CR);
234 while (readw(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
240 #endif /* CONFIG_HARD_I2C */