Re: [PATCH v7 4/5] i2c: aspeed: added driver for Aspeed I2C

Brendan Higgins
2017-05-08T23:35:02Z

Sorry for the spam everyone, email client did not do what I expected it to do.

I would like to release another version this week or next week, and I
think that we are pretty closed to having something we can apply, but
before I do that, I want to get something resolved:

> +static int __aspeed_i2c_init(struct aspeed_i2c_bus *bus,
> + struct platform_device *pdev)
> +{
> + int ret;
> +
> + /* Disable everything. */
> + writel(0, bus->base + ASPEED_I2C_FUN_CTRL_REG);
> +
> + ret = __aspeed_i2c_init_clk(bus, pdev);
> + if (ret < 0)
> + return ret;
> +
> + /* Enable Master Mode */
> + writel(readl(bus->base + ASPEED_I2C_FUN_CTRL_REG) |
> + ASPEED_I2CD_MASTER_EN |
> + /* TODO: provide device tree option for multi-master mode. */

I am curious what everyone thinks about this. It seemed that, earlier
on, people did not like me disabling multi-master mode, but I think
that it would make bus recovery not work as well. Given that, I think
it makes the most sense to provide a device tree option either to
enable multi-master support or disable it. Thoughts?

> + ASPEED_I2CD_MULTI_MASTER_DIS,
> + bus->base + ASPEED_I2C_FUN_CTRL_REG);
> +
> + /* Set interrupt generation of I2C controller */
> + writel(ASPEED_I2CD_INTR_ALL, bus->base + ASPEED_I2C_INTR_CTRL_REG);
> +
> + return 0;
> +}