/* * i2c driver for Freescale mx31 * * (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de> * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ #include <common.h> #if defined(CONFIG_HARD_I2C) #include <asm/arch/mx31.h> #include <asm/arch/mx31-regs.h> #define IADR 0x00 #define IFDR 0x04 #define I2CR 0x08 #define I2SR 0x0c #define I2DR 0x10 #define I2CR_IEN (1 << 7) #define I2CR_IIEN (1 << 6) #define I2CR_MSTA (1 << 5) #define I2CR_MTX (1 << 4) #define I2CR_TX_NO_AK (1 << 3) #define I2CR_RSTA (1 << 2) #define I2SR_ICF (1 << 7) #define I2SR_IBB (1 << 5) #define I2SR_IIF (1 << 1) #define I2SR_RX_NO_AK (1 << 0) #ifdef CONFIG_SYS_I2C_MX31_PORT1 #define I2C_BASE 0x43f80000 #define I2C_CLK_OFFSET 26 #elif defined (CONFIG_SYS_I2C_MX31_PORT2) #define I2C_BASE 0x43f98000 #define I2C_CLK_OFFSET 28 #elif defined (CONFIG_SYS_I2C_MX31_PORT3) #define I2C_BASE 0x43f84000 #define I2C_CLK_OFFSET 30 #else #error "define CONFIG_SYS_I2C_MX31_PORTx to use the mx31 I2C driver" #endif #ifdef DEBUG #define DPRINTF(args...) printf(args) #else #define DPRINTF(args...) #endif static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144, 160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960, 1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840}; void i2c_init(int speed, int unused) { int freq = mx31_get_ipg_clk(); int i; /* start the required I2C clock */ __REG(CCM_CGR0) = __REG(CCM_CGR0) | (3 << I2C_CLK_OFFSET); for (i = 0; i < 0x1f; i++) if (freq / div[i] <= speed) break; DPRINTF("%s: speed: %d\n",__FUNCTION__, speed); __REG16(I2C_BASE + I2CR) = 0; /* Reset module */ __REG16(I2C_BASE + IFDR) = i; __REG16(I2C_BASE + I2CR) = I2CR_IEN; __REG16(I2C_BASE + I2SR) = 0; } static int wait_busy(void) { int timeout = 10000; while (!(__REG16(I2C_BASE + I2SR) & I2SR_IIF) && --timeout) udelay(1); __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */ return timeout; } static int tx_byte(u8 byte) { __REG16(I2C_BASE + I2DR) = byte; if (!wait_busy() || __REG16(I2C_BASE + I2SR) & I2SR_RX_NO_AK) return -1; return 0; } static int rx_byte(void) { if (!wait_busy()) return -1; return __REG16(I2C_BASE + I2DR); } int i2c_probe(uchar chip) { int ret; __REG16(I2C_BASE + I2CR) = 0; /* Reset module */ __REG16(I2C_BASE + I2CR) = I2CR_IEN; __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX; ret = tx_byte(chip << 1); __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MTX; return ret; } static int i2c_addr(uchar chip, uint addr, int alen) { __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */ __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX; if (tx_byte(chip << 1)) return -1; while (alen--) if (tx_byte((addr >> (alen * 8)) & 0xff)) return -1; return 0; } int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) { int timeout = 10000; int ret; DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",__FUNCTION__, chip, addr, alen, len); if (i2c_addr(chip, addr, alen)) { printf("i2c_addr failed\n"); return -1; } __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX | I2CR_RSTA; if (tx_byte(chip << 1 | 1)) return -1; __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | ((len == 1) ? I2CR_TX_NO_AK : 0); ret = __REG16(I2C_BASE + I2DR); while (len--) { if ((ret = rx_byte()) < 0) return -1; *buf++ = ret; if (len <= 1) __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_TX_NO_AK; } wait_busy(); __REG16(I2C_BASE + I2CR) = I2CR_IEN; while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout) udelay(1); return 0; } int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len) { int timeout = 10000; DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",__FUNCTION__, chip, addr, alen, len); if (i2c_addr(chip, addr, alen)) return -1; while (len--) if (tx_byte(*buf++)) return -1; __REG16(I2C_BASE + I2CR) = I2CR_IEN; while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout) udelay(1); return 0; } #endif /* CONFIG_HARD_I2C */