| Message ID | 20220711042838.213351-1-y.oudjana@protonmail.com |
|---|---|
| Headers | show |
| Series | media: i2c: ak7375: Add regulator management | expand |
On 11/07/2022 06:28, Yassine Oudjana wrote: > From: Yassine Oudjana <y.oudjana@protonmail.com> > > Convert DT bindings document for AKM AK7375 VCM to DT schema > format and add an example. > > Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com> > --- > .../devicetree/bindings/media/i2c/ak7375.txt | 8 ---- > .../devicetree/bindings/media/i2c/ak7375.yaml | 41 +++++++++++++++++++ > MAINTAINERS | 2 +- > 3 files changed, 42 insertions(+), 9 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.txt > create mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.yaml > > diff --git a/Documentation/devicetree/bindings/media/i2c/ak7375.txt b/Documentation/devicetree/bindings/media/i2c/ak7375.txt > deleted file mode 100644 > index aa3e24b41241..000000000000 > --- a/Documentation/devicetree/bindings/media/i2c/ak7375.txt > +++ /dev/null > @@ -1,8 +0,0 @@ > -Asahi Kasei Microdevices AK7375 voice coil lens driver > - > -AK7375 is a camera voice coil lens. > - > -Mandatory properties: > - > -- compatible: "asahi-kasei,ak7375" > -- reg: I2C slave address > diff --git a/Documentation/devicetree/bindings/media/i2c/ak7375.yaml b/Documentation/devicetree/bindings/media/i2c/ak7375.yaml > new file mode 100644 > index 000000000000..4fc216846ae7 > --- /dev/null > +++ b/Documentation/devicetree/bindings/media/i2c/ak7375.yaml > @@ -0,0 +1,41 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/media/i2c/ak7375.yaml# Include vendor prefix in the file name, so: asahi-kasei,ak7375.yaml Best regards, Krzysztof
Hi Yassine On Mon, Jul 11, 2022 at 06:08:53PM +0400, Yassine Oudjana wrote: > > On Mon, Jul 11 2022 at 15:34:23 +0200, Jacopo Mondi <jacopo@jmondi.org> > wrote: > > Hello Yassine > > > > On Mon, Jul 11, 2022 at 08:28:39AM +0400, Yassine Oudjana wrote: > > > From: Yassine Oudjana <y.oudjana@protonmail.com> > > > > > > Make the driver get needed regulators on probe and enable/disable > > > them on runtime PM callbacks. > > > > > > Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com> > > > --- > > > drivers/media/i2c/ak7375.c | 39 > > > ++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 39 insertions(+) > > > > > > diff --git a/drivers/media/i2c/ak7375.c b/drivers/media/i2c/ak7375.c > > > index 40b1a4aa846c..59d5cb00e3ba 100644 > > > --- a/drivers/media/i2c/ak7375.c > > > +++ b/drivers/media/i2c/ak7375.c > > > @@ -6,6 +6,7 @@ > > > #include <linux/i2c.h> > > > #include <linux/module.h> > > > #include <linux/pm_runtime.h> > > > +#include <linux/regulator/consumer.h> > > > #include <media/v4l2-ctrls.h> > > > #include <media/v4l2-device.h> > > > > > > @@ -23,17 +24,32 @@ > > > */ > > > #define AK7375_CTRL_STEPS 64 > > > #define AK7375_CTRL_DELAY_US 1000 > > > +/* > > > + * The vcm takes around 3 ms to power on and start taking > > > + * I2C messages. This value was found experimentally due to > > > + * lack of documentation. 2 ms is added as a safety margin. > > > + */ > > > +#define AK7375_POWER_DELAY_US 5000 > > > > > > #define AK7375_REG_POSITION 0x0 > > > #define AK7375_REG_CONT 0x2 > > > #define AK7375_MODE_ACTIVE 0x0 > > > #define AK7375_MODE_STANDBY 0x40 > > > > > > +static const char * const ak7375_supply_names[] = { > > > + "vdd", > > > + "vio", > > > +}; > > > + > > > +#define AK7375_NUM_SUPPLIES ARRAY_SIZE(ak7375_supply_names) > > > + > > > /* ak7375 device structure */ > > > struct ak7375_device { > > > struct v4l2_ctrl_handler ctrls_vcm; > > > struct v4l2_subdev sd; > > > struct v4l2_ctrl *focus; > > > + struct regulator_bulk_data supplies[AK7375_NUM_SUPPLIES]; > > > + > > > /* active or standby mode */ > > > bool active; > > > }; > > > @@ -132,6 +148,7 @@ static int ak7375_init_controls(struct > > > ak7375_device *dev_vcm) > > > static int ak7375_probe(struct i2c_client *client) > > > { > > > struct ak7375_device *ak7375_dev; > > > + int i; > > > > I would have moved this one down to maintain variable declaration > > in the in-famous reverse-xmas-tree ordering. Up to you. > > I'm used to declaring variables in the order of first use, > but I don't really mind it either way. I'll move it down. > > > > > > int ret; > > > > > > ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev), > > > @@ -139,6 +156,17 @@ static int ak7375_probe(struct i2c_client > > > *client) > > > if (!ak7375_dev) > > > return -ENOMEM; > > > > > > + for (i = 0; i < AK7375_NUM_SUPPLIES; i++) > > > + ak7375_dev->supplies[i].supply = ak7375_supply_names[i]; > > > + > > > + ret = devm_regulator_bulk_get(&client->dev, AK7375_NUM_SUPPLIES, > > > + ak7375_dev->supplies); > > > + if (ret) { > > > + dev_err(&client->dev, "Failed to get regulators: %pe", > > > + ERR_PTR(ret)); > > > + return ret; > > > + } > > > + > > > v4l2_i2c_subdev_init(&ak7375_dev->sd, client, &ak7375_ops); > > > ak7375_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; > > > ak7375_dev->sd.internal_ops = &ak7375_int_ops; > > > @@ -210,6 +238,10 @@ static int __maybe_unused > > > ak7375_vcm_suspend(struct device *dev) > > > if (ret) > > > dev_err(dev, "%s I2C failure: %d\n", __func__, ret); > > > > > > + ret = regulator_bulk_disable(AK7375_NUM_SUPPLIES, > > > ak7375_dev->supplies); > > > + if (ret) > > > + return ret; > > > + > > > ak7375_dev->active = false; > > > > > > return 0; > > > @@ -230,6 +262,13 @@ static int __maybe_unused > > > ak7375_vcm_resume(struct device *dev) > > > if (ak7375_dev->active) > > > return 0; > > > > > > + ret = regulator_bulk_enable(AK7375_NUM_SUPPLIES, > > > ak7375_dev->supplies); > > > + if (ret) > > > + return ret; > > > + > > > + /* Wait for vcm to become ready */ > > > + usleep_range(AK7375_POWER_DELAY_US, AK7375_POWER_DELAY_US + 10); > > > + > > > > Isn't 10usec a very small delay to be given to usleep_range() for a > > delay of at least 3msec ? Also assuming 5msec just to be safe seems a > > little arbitrary. Adding 2 milliseconds in the wakeup path introduces > > a non-negligible delay. > > I must admit that I didn't give it too much thought. I just > did it similar to the other delay used in this driver > (AK7375_CTRL_DELAY_US). As for adding 2ms, I don't know what > the worst case wake-up time is since I don't have a datasheet > on hand, so I just wanted to stay safe. Also, this driver Oh sorry, I missed in the comment the value was found experimentally an it's not documented.. > doesn't really recover if it fails to resume (which is what > used to happen before adding a delay). Rounding up to 5ms > felt good enough. > > > > > It's likely a detail, but according to > > Documentation/timers/timers-howto.rst > > > > Since usleep_range is built on top of hrtimers, the > > wakeup will be very precise (ish), thus a simple > > usleep function would likely introduce a large number > > of undesired interrupts. > > > > With the introduction of a range, the scheduler is > > free to coalesce your wakeup with any other wakeup > > that may have happened for other reasons, or at the > > worst case, fire an interrupt for your upper bound. > > > > The larger a range you supply, the greater a chance > > that you will not trigger an interrupt; this should > > be balanced with what is an acceptable upper bound on > > delay / performance for your specific code path. Exact > > tolerances here are very situation specific, thus it > > is left to the caller to determine a reasonable range. > > > > If you have a min of 3msec I would try with a range of (3000, 3500). > > What do you think ? > > Seems good. I haven't yet had it fail to power on within 3ms of > turning on regulators so I guess there is no reason to worry about it. > Ok then :) There's anyway a comment that says the value comes from practical experience, so if anything bad happens, it's easy to track it down to that Thanks j > > > > > > ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT, > > > AK7375_MODE_ACTIVE, 1); > > > if (ret) { > > > -- > > > 2.37.0 > > > > Thanks for the review, > Yassine > >
From: Yassine Oudjana <y.oudjana@protonmail.com> This series adds needed regulator management for the AK7375 VCM. A DT schema conversion is made before adding new properties. Yassine Oudjana (3): media: dt-bindings: ak7375: Convert to DT schema media: dt-bindings: ak7375: Add supplies media: i2c: ak7375: Add regulator management .../devicetree/bindings/media/i2c/ak7375.txt | 8 --- .../devicetree/bindings/media/i2c/ak7375.yaml | 52 +++++++++++++++++++ MAINTAINERS | 2 +- drivers/media/i2c/ak7375.c | 39 ++++++++++++++ 4 files changed, 92 insertions(+), 9 deletions(-) delete mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.txt create mode 100644 Documentation/devicetree/bindings/media/i2c/ak7375.yaml