Amid a broadly downbeat day on the market, shares of Apple (NASDAQ:AAPL) are getting clobbered, down 5.1% as of 2:30 p.m. EDT. That puts the Mac maker at fresh 52-week lows and prices not seen since December 2011.

The biggest contributor to the drop was audio codec supplier Cirrus Logic's (NASDAQ:CRUS) preliminary results, which hit the wire last night. The company said it expects last quarter's revenue come to about $206.9 million, falling shy of the $210.2 million consensus estimate.

In addition, Cirrus is recording a net inventory reserve of $23.3 million, which includes $20.7 million related to a "decreased forecast for a high volume product as the customer migrates to one of Cirrus Logic's newer components." With Apple being the company's biggest customer by far and iPhones being the highest-volume product that Cirrus supplies components for, there's little doubt as to where the weakness is coming from.

Inventory reserves are created ahead of inventory writedowns, so Cirrus is expecting to take a loss on some of its inventory. The reserve is a high-end accounting estimate that's used while the company calculates its figures more specifically. Cirrus expects its gross margin to get hit by more than 10% (because the inventory reserve is charged as part of cost of goods sold).

Investor sentiment over Apple's near-term prospects have soured over the past few months as the company enters a lull in its product cycles and consumers potentially delay purchases in anticipation. The implication is that iPhone shipments are weak, which is directly impacting Cirrus Logic's top line and will subsequently put a dent in Apple's as well, even though Cirrus acknowledges that there's a migration to newer products taking place.

Apple reports earnings next Tuesday, and Cirrus will follow suit with its own full results next Thursday. Investors won't have to wait long to get more clarity on how the two are faring.