[U-Boot] [PATCH 03/24] mxc_i2c: create tx_byte function

Marek Vasut
2012-06-22T16:58:21Z

Dear Troy Kisky,

> Use tx_byte function instead of having 3 copies
> of the code.
>
> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
> ---
> drivers/i2c/mxc_i2c.c | 72
> +++++++++++++++---------------------------------- 1 file changed, 21
> insertions(+), 51 deletions(-)
>
> diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
> index 0b46c9c..0fd508a 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;
> + unsigned 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;
> }
>
> @@ -322,13 +297,14 @@ 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);
> + ret = tx_byte(i2c_regs, chip << 1);
> if (ret)
> return ret;
>
> @@ -352,7 +328,7 @@ 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);
> + ret = tx_byte(i2c_regs, chip << 1);
> if (ret)
> return ret;
>
> @@ -364,7 +340,7 @@ 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);
> + ret = tx_byte(i2c_regs, (chip << 1) | 1);

Isn't this | 1 and | 0 stuff #define-d somewhere? I think there was
I2C_READ_SOMETHING in i2c.h and I2C_WRITE_SOMETHING...

> if (ret)
> return ret;
>

Otherwise
Acked-by: Marek Vasut <marex@denx.de>

Best regards,
Marek Vasut