Messages in this thread Patch in this message | | | Date | Thu, 14 Jul 2022 17:56:29 +0400 | From | Yassine Oudjana <> | Subject | Re: [PATCH v2 3/3] media: i2c: ak7375: Add regulator management |
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On Mon, Jul 11 2022 at 19:31:23 +0200, Jacopo Mondi <jacopo@jmondi.org> wrote: > Hi Yassine, > > On Mon, Jul 11, 2022 at 06:40:39PM +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> >> --- >> Changes since v1: >> - Reorganize variable declaration >> - Change the power-on delay range to 3000-3500 microseconds. >> >> 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..c2b2542a0056 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. >> + */ >> +#define AK7375_POWER_DELAY_US 3000 >> >> #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; >> }; >> @@ -133,12 +149,24 @@ static int ak7375_probe(struct i2c_client >> *client) >> { >> struct ak7375_device *ak7375_dev; >> int ret; >> + int i; >> >> ak7375_dev = devm_kzalloc(&client->dev, sizeof(*ak7375_dev), >> GFP_KERNEL); >> 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)); > > Why are you using %pe here ? Your return value is not a pointer
In order to have it print a symbolic error name instead of a value with CONFIG_SYMBOLIC_ERRNAME=y. There is no format code for an error integer (or at least I couldn't find one mentioned anywhere in the docs), so instead I use %pe then wrap `ret` in ERR_PTR().
> (Also, missing \n at the end of the string)
That wasn't intentional. I'll fix it.
> > From Documentation/core-api/printk-formats.rst: > %pe -ENOSPC > > For printing error pointers (i.e. a pointer for which IS_ERR() is > true) > as a symbolic error name. Error values for which no symbolic name is > known are printed in decimal, while a non-ERR_PTR passed as the > argument to %pe gets treated as ordinary %p. > >> + 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 + 500); >> + >> ret = ak7375_i2c_write(ak7375_dev, AK7375_REG_CONT, >> AK7375_MODE_ACTIVE, 1); >> if (ret) { >> -- >> 2.37.0 >>
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