On Wed, 2017-08-30 at 14:17 +0800, Phil Reid wrote:
> From: Tim Sander <tim@xxxxxxxxxxxxxxx>
>
> This patch contains much input from Phil Reid and has been tested
> on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the
> SCL and SDA GPIO's. I am still a little unsure about the recover
> in the timeout case (i2c-designware-core.c:770) as i could not
> test this codepath.
> - if (abort_source & DW_IC_TX_ARB_LOST)
> + if (abort_source & DW_IC_TX_ARB_LOST) {
> + i2c_recover_bus(&dev->adapter);
> return -EAGAIN;
> - else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
> + } else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
else is redundant.
> return -EINVAL; /* wrong msgs[] data */
> else
Ditto.
> return -EIO;
> +static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> +{
> + struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> + struct i2c_adapter *adap = &dev->adapter;
> + struct gpio_desc *gpio;
> + int r;
> +
> + gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);
> + if (IS_ERR(gpio)) {
> + r = PTR_ERR(gpio);
> + if ((r == -ENOENT) || (r == -ENOENT))
Copy'n'paste typo?
> + return 0;
> + return r;
> + }
> + rinfo->scl_gpiod = gpio;
> +
> + gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
> + if (IS_ERR(gpio))
> + return PTR_ERR(gpio);
> + rinfo->sda_gpiod = gpio;
> +
> + rinfo->recover_bus = i2c_generic_scl_recovery;
> + rinfo->prepare_recovery = i2c_dw_prepare_recovery;
> + rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
> + adap->bus_recovery_info = rinfo;
> +
> + dev_info(dev->dev,
> + "adapter: %s running with gpio recovery mode! scl:%i
> sda:%i\n",
> + adap->name, !!rinfo->scl_gpiod, !!rinfo->sda_gpiod);
Instead of doing numbers, better just to list available descriptors,
e.g.
...("... %s scl\n", rinfo->sda_gpiod ? "sda,");
No need to explain that scl doesn't need any check here.
And I'm not sure why do you need adap->name here. Can you show an
example of output from your test platform?
> + if (!ret)
> + ret = i2c_dw_init_recovery_info(dev);
Better to
if (ret)
return ret;
return i2c...();
> +
> return ret;
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
