Re: [PATCH 04/12] I2C re-init for every cmd

[Kevin Hilman <khilman@deeprootsystems.com>]

jouni.hogander@nokia.com (Högander Jouni) writes:

> "ext chandra shekhar" <x0044955@ti.com> writes:
>
>> agreed..but i guess it will not compile for 2430 and prev. platforms.
>> omap3_i2c_save_context and restore definition is under macro
>> while call is not. let me know if i am missing something.
>>
>> also is SYSC register restore needed??
>
> Here is the second version. Does it look any better to you?
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 3778735..0a11621 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -147,6 +147,12 @@ struct omap_i2c_dev {
>         unsigned                b_hw:1;         /* bad h/w fixes */
>         unsigned                idle:1;
>         u16                     iestate;        /* Saved interrupt register */
> +#ifdef CONFIG_ARCH_OMAP34XX
> +       u16                     pscstate;
> +       u16                     scllstate;
> +       u16                     sclhstate;
> +       u16                     bufstate;
> +#endif
>  };
>  
>  static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
> @@ -209,16 +215,21 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
>         if (dev->iclk != NULL)
>                 clk_enable(dev->iclk);
>         clk_enable(dev->fclk);
> +
> +#ifdef CONFIG_ARCH_OMAP34XX
> +       omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
> +       omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
> +       omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
> +       omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
> +#endif

The above should also be inside an if cpu_is_omap34xx() block so
it works correctly on multi-omap kernels.

Kevin

>         dev->idle = 0;
> -       if (dev->iestate)
> -               omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
> +       omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
>  }
>  
>  static void omap_i2c_idle(struct omap_i2c_dev *dev)
>  {
>         u16 iv;
>  
> -       dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
>         omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
>         if (dev->rev1)
>                 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
> @@ -238,7 +249,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
>  
>  static int omap_i2c_init(struct omap_i2c_dev *dev)
>  {
> -       u16 psc = 0, scll = 0, sclh = 0;
> +       u16 psc = 0, scll = 0, sclh = 0, buf = 0;
>         u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
>         unsigned long fclk_rate = 12000000;
>         unsigned long timeout;
> @@ -327,23 +338,30 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
>         omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
>         omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
>  
> -       if (dev->fifo_size)
> -               /* Note: setup required fifo size - 1 */
> -               omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG,
> -                                       (dev->fifo_size - 1) << 8 | /* RTRSH */
> -                                       OMAP_I2C_BUF_RXFIF_CLR |
> -                                       (dev->fifo_size - 1) | /* XTRSH */
> -                                       OMAP_I2C_BUF_TXFIF_CLR);
> +       if (dev->fifo_size) {
> +               /* Note: setup required fifo size - 1. RTRSH and XTRSH */
> +               buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
> +                       (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
> +               omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
> +       }
>  
>         /* Take the I2C module out of reset: */
>         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
>  
>         /* Enable interrupts */
> -       omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
> -                       (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
> +       dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
>                         OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
>                         OMAP_I2C_IE_AL)  | ((dev->fifo_size) ?
> -                               (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0));
> +                                           (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
> +       omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
> +
> +#ifdef CONFIG_ARCH_OMAP34XX
> +       dev->pscstate = psc;
> +       dev->scllstate = scll;
> +       dev->sclhstate = sclh;
> +       dev->bufstate = buf;
> +#endif
> +
>         return 0;
>  }
>  
> @@ -496,8 +514,6 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>  
>         omap_i2c_unidle(dev);
>  
> -       omap_i2c_init(dev);
> -
>         if ((r = omap_i2c_wait_for_bb(dev)) < 0)
>                 goto out;
>
> -- 
> Jouni Högander
>
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