[PATCH v5] I2C: add CSR SiRFprimaII on-chip I2C controllers driver

Wolfram Sang w.sang at pengutronix.de
Mon Feb 6 17:47:14 EST 2012


> > Thanks for your contribution! Is there a free datasheet for this controller
> > available?
> 
> sorry. not available to public yet.

:( Can you cite what "SIRFSOC_I2C_NACK" does?
> 
> >> +struct sirfsoc_i2c {
> >> +     void __iomem *base;
> >> +     struct clk *clk;
> >> +     unsigned long speed;    /* I2C SCL frequency */
> >> +     int irq;
> >
> > Do you really need those two?
> 
> irq can be deleted. speed is not really needed if you don't like.

It is not about "like". It is not needed, or?

> >> +static void i2c_sirfsoc_queue_cmd(struct sirfsoc_i2c *siic)
> >> +{
> >> +     u32 regval;
> >> +     int i = 0;
> >> +
> >> +     if (siic->msg_read) {
> >> +             while (((siic->finished_len + i) < siic->msg_len)
> >> +                     && (siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) {
> >
> > Either use a different indentation for the above line or add a newline below.
> > It is hard to see where the while() ends and the code block starts.
> 
> i just want to make sure what you want is:
> 
>              while (((siic->finished_len + i) < siic->msg_len)
>                      &&(siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)
>                      ) {
> ?
> or something else?

I thought of (which is simpler IMO):

>              while (((siic->finished_len + i) < siic->msg_len)
>                      &&(siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) {
>
>                      regval = SIRFSOC_I2C_READ | SIRFSOC_I2C_CMD_RP(0);


The other solution would be (not sure if it fits the line length):

> >> +             while (((siic->finished_len + i) < siic->msg_len)
> >> +   	                  && (siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) {
> >> +                     regval = SIRFSOC_I2C_READ | SIRFSOC_I2C_CMD_RP(0);

The idea is to make it easier (visually) what is the while-condition and where
is the code of the while-block. I thought that was difficult in original version.

> >> +static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
> >> +{
> >> +     u32 regval = readl(siic->base + SIRFSOC_I2C_CTRL);
> >> +     int timeout = (msg->len + 1) * 50;
> >
> > That looks broken. What is 50 here?
> 
> just multiple of xfer bytes for defining a timeout. i might have a comment here.

That probably won't help. I'd think you want a *_to_jiffies() here to define a
proper timeout value in usecs/msecs?

> >> +     siic->irq = platform_get_irq(pdev, 0);
> >> +     if (siic->irq < 0) {
> >> +             err = -EINVAL;
> >> +             goto out;
> >> +     }
> >
> > return the error code here?
> 
> out lable will free resources and return error code.

Sorry, I meant the error code you received which is in siic->irq.

Regards,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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