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,
27 #if defined(CONFIG_HARD_I2C)
29 #if defined(CONFIG_MX31)
30 #include <asm/arch/mx31.h>
31 #include <asm/arch/mx31-regs.h>
34 #if defined(CONFIG_MX53)
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
70 #error "define CONFIG_SYS_I2C_MXxx_PORTx to use the I2C driver"
74 #define DPRINTF(args...) printf(args)
76 #define DPRINTF(args...)
79 static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144,
80 160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960,
81 1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840};
83 void i2c_init(int speed, int unused)
88 #if defined(CONFIG_MX31)
89 freq = mx31_get_ipg_clk();
90 /* start the required I2C clock */
91 __REG(CCM_CGR0) = __REG(CCM_CGR0) | (3 << I2C_CLK_OFFSET);
93 freq = mxc_get_clock(MXC_IPG_PERCLK);
96 for (i = 0; i < 0x1f; i++)
97 if (freq / div[i] <= speed)
100 DPRINTF("%s: speed: %d\n",__FUNCTION__, speed);
102 __REG16(I2C_BASE + I2CR) = 0; /* Reset module */
103 __REG16(I2C_BASE + IFDR) = i;
104 __REG16(I2C_BASE + I2CR) = I2CR_IEN;
105 __REG16(I2C_BASE + I2SR) = 0;
108 static int wait_busy(void)
112 while (!(__REG16(I2C_BASE + I2SR) & I2SR_IIF) && --timeout)
114 __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
119 static int tx_byte(u8 byte)
121 __REG16(I2C_BASE + I2DR) = byte;
123 if (!wait_busy() || __REG16(I2C_BASE + I2SR) & I2SR_RX_NO_AK)
128 static int rx_byte(void)
133 return __REG16(I2C_BASE + I2DR);
136 int i2c_probe(uchar chip)
140 __REG16(I2C_BASE + I2CR) = 0; /* Reset module */
141 __REG16(I2C_BASE + I2CR) = I2CR_IEN;
143 __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX;
144 ret = tx_byte(chip << 1);
145 __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MTX;
150 static int i2c_addr(uchar chip, uint addr, int alen)
152 __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
153 __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX;
155 if (tx_byte(chip << 1))
159 if (tx_byte((addr >> (alen * 8)) & 0xff))
164 int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
169 DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",__FUNCTION__, chip, addr, alen, len);
171 if (i2c_addr(chip, addr, alen)) {
172 printf("i2c_addr failed\n");
176 __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX | I2CR_RSTA;
178 if (tx_byte(chip << 1 | 1))
181 __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | ((len == 1) ? I2CR_TX_NO_AK : 0);
183 ret = __REG16(I2C_BASE + I2DR);
186 if ((ret = rx_byte()) < 0)
190 __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_TX_NO_AK;
195 __REG16(I2C_BASE + I2CR) = I2CR_IEN;
197 while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
203 int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
206 DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",__FUNCTION__, chip, addr, alen, len);
208 if (i2c_addr(chip, addr, alen))
215 __REG16(I2C_BASE + I2CR) = I2CR_IEN;
217 while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
223 #endif /* CONFIG_HARD_I2C */