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

+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?