diff options
| -rw-r--r-- | drivers/i2c/mxc_i2c.c | 82 |
1 files changed, 24 insertions, 58 deletions
diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c index 0b46c9c..d147dd5 100644 --- a/drivers/i2c/mxc_i2c.c +++ b/drivers/i2c/mxc_i2c.c @@ -33,6 +33,7 @@ #include <common.h> #include <asm/arch/clock.h> #include <asm/arch/imx-regs.h> +#include <asm/errno.h> #include <asm/io.h> #include <i2c.h> @@ -207,17 +208,21 @@ int i2c_imx_trx_complete(void) udelay(1); } - return 1; + return -ETIMEDOUT; } -/* - * Check if the transaction was ACKed - */ -int i2c_imx_acked(void) +static int tx_byte(struct mxc_i2c_regs *i2c_regs, u8 byte) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; + int ret; - return readb(&i2c_regs->i2sr) & I2SR_RX_NO_AK; + writeb(byte, &i2c_regs->i2dr); + ret = i2c_imx_trx_complete(); + if (ret < 0) + return ret; + ret = readb(&i2c_regs->i2sr); + if (ret & I2SR_RX_NO_AK) + return -ENODEV; + return 0; } /* @@ -271,30 +276,6 @@ void i2c_imx_stop(void) } /* - * Set chip address and access mode - * - * read = 1: READ access - * read = 0: WRITE access - */ -int i2c_imx_set_chip_addr(uchar chip, int read) -{ - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - int ret; - - writeb((chip << 1) | read, &i2c_regs->i2dr); - - ret = i2c_imx_trx_complete(); - if (ret) - return ret; - - ret = i2c_imx_acked(); - if (ret) - return ret; - - return ret; -} - -/* * Write register address */ int i2c_imx_set_reg_addr(uint addr, int alen) @@ -303,14 +284,8 @@ int i2c_imx_set_reg_addr(uint addr, int alen) int ret = 0; while (alen--) { - writeb((addr >> (alen * 8)) & 0xff, &i2c_regs->i2dr); - - ret = i2c_imx_trx_complete(); - if (ret) - break; - - ret = i2c_imx_acked(); - if (ret) + ret = tx_byte(i2c_regs, (addr >> (alen * 8)) & 0xff); + if (ret < 0) break; } @@ -322,18 +297,15 @@ int i2c_imx_set_reg_addr(uint addr, int alen) */ int i2c_probe(uchar chip) { + struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; int ret; ret = i2c_imx_start(); if (ret) return ret; - ret = i2c_imx_set_chip_addr(chip, 0); - if (ret) - return ret; - + ret = tx_byte(i2c_regs, chip << 1); i2c_imx_stop(); - return ret; } @@ -352,8 +324,8 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) return ret; /* write slave address */ - ret = i2c_imx_set_chip_addr(chip, 0); - if (ret) + ret = tx_byte(i2c_regs, chip << 1); + if (ret < 0) return ret; ret = i2c_imx_set_reg_addr(addr, alen); @@ -364,8 +336,8 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) temp |= I2CR_RSTA; writeb(temp, &i2c_regs->i2cr); - ret = i2c_imx_set_chip_addr(chip, 1); - if (ret) + ret = tx_byte(i2c_regs, (chip << 1) | 1); + if (ret < 0) return ret; /* setup bus to read data */ @@ -419,8 +391,8 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len) return ret; /* write slave address */ - ret = i2c_imx_set_chip_addr(chip, 0); - if (ret) + ret = tx_byte(i2c_regs, chip << 1); + if (ret < 0) return ret; ret = i2c_imx_set_reg_addr(addr, alen); @@ -428,14 +400,8 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len) return ret; for (i = 0; i < len; i++) { - writeb(buf[i], &i2c_regs->i2dr); - - ret = i2c_imx_trx_complete(); - if (ret) - return ret; - - ret = i2c_imx_acked(); - if (ret) + ret = tx_byte(i2c_regs, buf[i]); + if (ret < 0) return ret; } |