Re: [alsa-devel] [PATCH 06/10] mfd: Add core driver for AD242x A2B transceivers

Pierre-Louis Bossart
2019-12-17T19:16:04Z

> +config MFD_AD242X
> + bool "Analog Devices AD242x A2B support"
> + select MFD_CORE
> + select REGMAP_I2C
> + depends on I2C=y && OF

is there a specific reason why I2C needs to be built-in (as opposed to 'm')?

> +/* See Table 3-2 in the datasheet */

is the datasheet public? I thought it was only available under NDA.

> + master->sync_clk = devm_clk_get(dev, "sync");
> + if (IS_ERR(master->sync_clk)) {
> + ret = PTR_ERR(master->sync_clk);
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "failed to get sync clk: %d\n", ret);
> +
> + return ret;
> + }
> +
> + if (of_property_read_u32(dev->of_node, "clock-frequency",
> + &master->sync_clk_rate)) {
> + ret = clk_set_rate(master->sync_clk, master->sync_clk_rate);

shouldn't you check the rate before setting it?

> + if (ret < 0) {
> + dev_err(dev, "Cannot set sync clock rate: %d\n", ret);
> + return ret;
> + }
> + }
> +
> + master->sync_clk_rate = clk_get_rate(master->sync_clk);
> + if (master->sync_clk_rate != 44100 && master->sync_clk_rate != 48000) {
> + dev_err(dev, "SYNC clock rate %d is invalid\n",
> + master->sync_clk_rate);
> + return -EINVAL;
> + }

this is a bit odd, you set the rate in case there is a property but get
it anyways. the last block could be an else?

> +
> + ret = clk_prepare_enable(master->sync_clk);
> + if (ret < 0) {
> + dev_err(dev, "failed to enable sync clk: %d\n", ret);
> + return ret;
> + }
> +
> + /* Master node setup */
> +
> + ret = regmap_write(regmap, AD242X_CONTROL,
> + AD242X_CONTROL_MSTR | AD242X_CONTROL_SOFTRST);
> + if (ret < 0)
> + return ret;
> +
> + ret = ad242x_wait_for_irq(master, &master->run_completion, 10);

what is 10?

> +static int ad242x_master_remove(struct i2c_client *i2c)
> +{
> + struct ad242x_master *master = i2c_get_clientdata(i2c);
> +
> + if (master->sync_clk)
> + clk_disable_unprepare(master->sync_clk);

earlier you tested for IS_ERR(master->sync_clk)?

> + for (i = 0; i < 4; i++) {

what is 4? 4 hops?