Commit dc43f46a authored May 31, 2017 by Charles Keepax Committed by Mark Brown Jun 06, 2017

ASoC: cs35l35: Add additional delay for reset

Very fast systems may violate the minimum constraints for time the reset
line needs to remain low, or communicate with the device too soon after
releasing the reset. Fix this by adding some delays in to allow the chip
to properly reset, also factor out the reset into a function as it is
likely it will be re-used in later additions to the driver.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Paul Handrigan <Paul.Handrigan@cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 2ea659a9

sound/soc/codecs/cs35l35.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -162,6 +162,14 @@ static bool cs35l35_precious_register(struct device *dev, unsigned int reg)
		}
		}

		static void cs35l35_reset(struct cs35l35_private *cs35l35)
		{
		gpiod_set_value_cansleep(cs35l35->reset_gpio, 0);
		usleep_range(2000, 2100);
		gpiod_set_value_cansleep(cs35l35->reset_gpio, 1);
		usleep_range(1000, 1100);
		}

		static int cs35l35_wait_for_pdn(struct cs35l35_private *cs35l35)
		{
		int ret;
		@@ -1454,7 +1462,7 @@ static int cs35l35_i2c_probe(struct i2c_client *i2c_client,
		}
		}

		gpiod_set_value_cansleep(cs35l35->reset_gpio, 1);
		cs35l35_reset(cs35l35);

		init_completion(&cs35l35->pdn_done);