Re: [PATCH v4 03/20] mfd: adp5585: enable oscilator during probe
From: Lee Jones <lee@kernel.org>
Date: 2025-06-12 15:20:34
Also in:
linux-devicetree, linux-gpio, linux-pwm
On Thu, 12 Jun 2025, Nuno Sá wrote:
On Thu, 2025-06-12 at 15:20 +0100, Lee Jones wrote:quoted
On Wed, 21 May 2025, Nuno Sá via B4 Relay wrote:quoted
From: Nuno Sá <nuno.sa@analog.com> Make sure to enable the oscillator in the top device. This will allow to not control this in the child PWM device as that would not work with future support for keyboard matrix where the oscillator needs to be always enabled (and so cannot be disabled by disabling PWM). Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Nuno Sá <nuno.sa@analog.com> --- drivers/mfd/adp5585.c | 23 +++++++++++++++++++++++ drivers/pwm/pwm-adp5585.c | 5 ----- 2 files changed, 23 insertions(+), 5 deletions(-)diff --git a/drivers/mfd/adp5585.c b/drivers/mfd/adp5585.cindex 806867c56d6fb4ef1f461af26a424a3a05f46575..f3b74f7d6040413d066eb6dbaecfa3d5e6 ee06bd 100644--- a/drivers/mfd/adp5585.c +++ b/drivers/mfd/adp5585.c@@ -147,6 +147,13 @@ static int adp5585_add_devices(struct device *dev)return ret; } +static void adp5585_osc_disable(void *data) +{ + const struct adp5585_dev *adp5585 = data; + + regmap_write(adp5585->regmap, ADP5585_GENERAL_CFG, 0); +} + static int adp5585_i2c_probe(struct i2c_client *i2c) { const struct regmap_config *regmap_config;@@ -175,6 +182,22 @@ static int adp5585_i2c_probe(struct i2c_client *i2c)return dev_err_probe(&i2c->dev, -ENODEV, "Invalid device ID 0x%02x\n", id); + /* + * Enable the internal oscillator, as it's shared between multiple + * functions. + * + * As a future improvement, power consumption could possibly be + * decreased in some use cases by enabling and disabling the oscillator + * dynamically based on the needs of the child drivers.This is normal. What's stopping us from doing this from the offset?This is always needed when we have the input device registered. From my testing, we also need it for GPIOs configured as input. So basically the only reason this is not being done now is that it would not be trivial or really straightforward and honestly the series is already big enough :)
Agreed!
Laurent also agreed with this not being mandatory now so hopefully it's also fine with you.
If there is no explicit plan to do this in the future, you may as well remove the comment. TODOs have a tendency to rot after code is accepted. -- Lee Jones [李琼斯]