Messages in this thread |  | | Subject | Re: [PATCH v5 3/3] media: i2c: imx274: Add IMX274 power on and off sequence | From | Sowjanya Komatineni <> | Date | Thu, 3 Sep 2020 09:25:44 -0700 |
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On 9/3/20 8:03 AM, Jacopo Mondi wrote: > Hello, > > On Tue, Sep 01, 2020 at 07:04:38PM -0700, Sowjanya Komatineni wrote: >> IMX274 has VANA analog 2.8V supply, VDIG digital core 1.8V supply, >> and VDDL digital io 1.2V supply which are optional based on camera >> module design. >> >> IMX274 also need external 24Mhz clock and is optional based on >> camera module design. >> >> This patch adds support for IMX274 power on and off to enable and >> disable these supplies and external clock. >> >> Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net> >> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> >> --- >> drivers/media/i2c/imx274.c | 134 ++++++++++++++++++++++++++++++++++++++++++++- >> 1 file changed, 131 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c >> index a4b9dfd..79bfac3c6 100644 >> --- a/drivers/media/i2c/imx274.c >> +++ b/drivers/media/i2c/imx274.c >> @@ -18,7 +18,9 @@ >> #include <linux/kernel.h> >> #include <linux/module.h> >> #include <linux/of_gpio.h> >> +#include <linux/pm_runtime.h> >> #include <linux/regmap.h> >> +#include <linux/regulator/consumer.h> >> #include <linux/slab.h> >> #include <linux/v4l2-mediabus.h> >> #include <linux/videodev2.h> >> @@ -131,6 +133,15 @@ >> #define IMX274_TABLE_WAIT_MS 0 >> #define IMX274_TABLE_END 1 >> >> +/* regulator supplies */ >> +static const char * const imx274_supply_names[] = { >> + "vddl", /* IF (1.2V) supply */ >> + "vdig", /* Digital Core (1.8V) supply */ >> + "vana", /* Analog (2.8V) supply */ >> +}; >> + >> +#define IMX274_NUM_SUPPLIES ARRAY_SIZE(imx274_supply_names) >> + >> /* >> * imx274 I2C operation related structure >> */ >> @@ -501,6 +512,8 @@ struct imx274_ctrls { >> * @frame_rate: V4L2 frame rate structure >> * @regmap: Pointer to regmap structure >> * @reset_gpio: Pointer to reset gpio >> + * @supplies: List of analog and digital supply regulators >> + * @inck: Pointer to sensor input clock >> * @lock: Mutex structure >> * @mode: Parameters for the selected readout mode >> */ >> @@ -514,6 +527,8 @@ struct stimx274 { >> struct v4l2_fract frame_interval; >> struct regmap *regmap; >> struct gpio_desc *reset_gpio; >> + struct regulator_bulk_data supplies[IMX274_NUM_SUPPLIES]; >> + struct clk *inck; >> struct mutex lock; /* mutex lock for operations */ >> const struct imx274_mode *mode; >> }; >> @@ -767,6 +782,75 @@ static void imx274_reset(struct stimx274 *priv, int rst) >> usleep_range(IMX274_RESET_DELAY1, IMX274_RESET_DELAY2); >> } >> >> +/* >> + * imx274_power_on - Function called to power on the sensor >> + * @imx274: Pointer to device structure >> + */ > Can I say this does not bring much value ? :) > Also the parameter name is wrong > >> +static int imx274_power_on(struct device *dev) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct v4l2_subdev *sd = i2c_get_clientdata(client); >> + struct stimx274 *imx274 = to_imx274(sd); >> + int ret; >> + >> + /* keep sensor in reset before power on */ >> + imx274_reset(imx274, 0); >> + >> + ret = clk_prepare_enable(imx274->inck); >> + if (ret) { >> + dev_err(&imx274->client->dev, >> + "Failed to enable input clock: %d\n", ret); >> + return ret; >> + } >> + >> + ret = regulator_bulk_enable(IMX274_NUM_SUPPLIES, imx274->supplies); >> + if (ret) { >> + dev_err(&imx274->client->dev, >> + "Failed to enable regulators: %d\n", ret); >> + goto fail_reg; >> + } >> + >> + usleep_range(1, 2); > usleep_range() allows you to provide an interval in which your timeout > can be coalesced with others. Giving a [1usec, 2usec] range kind of > defeat the purpose. And most than everything, does sleeping for 2usec > serve any real purpose ?
Following delay recommendation from DS for power on sequence.
> > >> + imx274_reset(imx274, 1); >> + >> + return 0; >> + >> +fail_reg: >> + regulator_bulk_disable(IMX274_NUM_SUPPLIES, imx274->supplies); > regulator_bulk_enable() disables all the regulators that were enabled > before the one that failed, so I don't think you need this one here > >> + clk_disable_unprepare(imx274->inck); >> + return ret; >> +} >> + >> +/* >> + * imx274_power_off - Function called to power off the sensor >> + * @imx274: Pointer to device structure >> + */ > Same as the above one > >> +static int imx274_power_off(struct device *dev) >> +{ >> + struct i2c_client *client = to_i2c_client(dev); >> + struct v4l2_subdev *sd = i2c_get_clientdata(client); >> + struct stimx274 *imx274 = to_imx274(sd); >> + >> + imx274_reset(imx274, 0); >> + > Is reset before power-off necessary ?
Its recommended power off sequence as per data sheet.
Safe to keep sensor in reset before powering down one regulator at a time.
> >> + regulator_bulk_disable(IMX274_NUM_SUPPLIES, imx274->supplies); >> + >> + clk_disable_unprepare(imx274->inck); >> + >> + return 0; >> +} >> + >> +static int imx274_get_regulators(struct device *dev, struct stimx274 *imx274) > For symmetry with the regulators API I would call this > imx274_regulators_get(). Up to you :) > >> +{ >> + unsigned int i; >> + >> + for (i = 0; i < IMX274_NUM_SUPPLIES; i++) >> + imx274->supplies[i].supply = imx274_supply_names[i]; >> + >> + return devm_regulator_bulk_get(dev, IMX274_NUM_SUPPLIES, >> + imx274->supplies); > ^ not sure if it's my email > client but you might have a > wrong indent here > > Also, the regulators are optional in the bindings, how do the > regulators API cope with that ? I had a look around and they seems to > assume regulators are provided. I might be mistaken though
Yes these are optional regulators and based on feedback from sakari changed to use regulator_bulk_get() here.
regulator_bulk_get() uses NORMAL_GET and in case if supplies is not found it will use dummy regulator.
>> +} >> + >> /** >> * imx274_s_ctrl - This is used to set the imx274 V4L2 controls >> * @ctrl: V4L2 control to be set >> @@ -781,6 +865,9 @@ static int imx274_s_ctrl(struct v4l2_ctrl *ctrl) >> struct stimx274 *imx274 = to_imx274(sd); >> int ret = -EINVAL; >> >> + if (!pm_runtime_get_if_in_use(&imx274->client->dev)) >> + return 0; >> + > Right, but then you should call __v4l2_ctrl_handler_setup() in the > s_stream(1) call path to have controls updated (after > pm_runtime_get_sync() call for power on). I had a look at it seems > only exposure is updated.
Existing driver does v4l2_ctrl_handler_setup() in probe(). So, sensor power on happens prior to that in probe() and then powers down during idle.
> >> dev_dbg(&imx274->client->dev, >> "%s : s_ctrl: %s, value: %d\n", __func__, >> ctrl->name, ctrl->val); >> @@ -811,6 +898,8 @@ static int imx274_s_ctrl(struct v4l2_ctrl *ctrl) >> break; >> } >> >> + pm_runtime_put(&imx274->client->dev); >> + >> return ret; >> } >> >> @@ -1327,6 +1416,13 @@ static int imx274_s_stream(struct v4l2_subdev *sd, int on) >> mutex_lock(&imx274->lock); >> >> if (on) { >> + ret = pm_runtime_get_sync(&imx274->client->dev); >> + if (ret < 0) { >> + pm_runtime_put_noidle(&imx274->client->dev); >> + mutex_unlock(&imx274->lock); >> + return ret; >> + } >> + >> /* load mode registers */ >> ret = imx274_mode_regs(imx274); >> if (ret) >> @@ -1362,6 +1458,7 @@ static int imx274_s_stream(struct v4l2_subdev *sd, int on) >> ret = imx274_write_table(imx274, imx274_stop); >> if (ret) >> goto fail; >> + pm_runtime_put(&imx274->client->dev); >> } >> >> mutex_unlock(&imx274->lock); >> @@ -1369,6 +1466,7 @@ static int imx274_s_stream(struct v4l2_subdev *sd, int on) >> return 0; >> >> fail: >> + pm_runtime_put(&imx274->client->dev); >> mutex_unlock(&imx274->lock); >> dev_err(&imx274->client->dev, "s_stream failed\n"); >> return ret; >> @@ -1834,6 +1932,14 @@ static int imx274_probe(struct i2c_client *client) >> >> mutex_init(&imx274->lock); >> >> + imx274->inck = devm_clk_get_optional(&client->dev, "inck"); > clk_get_optional() might return error. I would check this with IS_ERR > >> + ret = imx274_get_regulators(&client->dev, imx274); >> + if (ret) { >> + dev_err(&client->dev, >> + "Failed to get power regulators, err: %d\n", ret); >> + return ret; >> + } >> + >> /* initialize format */ >> imx274->mode = &imx274_modes[IMX274_DEFAULT_BINNING]; >> imx274->crop.width = IMX274_MAX_WIDTH; >> @@ -1881,15 +1987,23 @@ static int imx274_probe(struct i2c_client *client) >> goto err_me; >> } >> >> - /* pull sensor out of reset */ >> - imx274_reset(imx274, 1); >> + /* power on the sensor */ >> + ret = imx274_power_on(&client->dev); >> + if (ret < 0) { >> + dev_err(&client->dev, >> + "%s : imx274 power on failed\n", __func__); >> + goto err_me; >> + } > Doesn't pm_runtime_get calls the poweron function for you ? > > But anyway, I don't see the device being probed for, in example, > querying it's VID/PID for identification during the driver's probe > routine. Do you need to power on ?
existing driver does v4l2_ctrl handler setup and loads sensor default control values during probe.
So doing sensor power_on here prior to setup. Power off happens during idle.
> >> + >> + pm_runtime_set_active(&client->dev); >> + pm_runtime_enable(&client->dev); >> >> /* initialize controls */ >> ret = v4l2_ctrl_handler_init(&imx274->ctrls.handler, 4); >> if (ret < 0) { >> dev_err(&client->dev, >> "%s : ctrl handler init Failed\n", __func__); >> - goto err_me; >> + goto err_disable_rpm; >> } >> >> imx274->ctrls.handler.lock = &imx274->lock; >> @@ -1951,11 +2065,16 @@ static int imx274_probe(struct i2c_client *client) >> goto err_ctrls; >> } >> >> + pm_runtime_idle(&client->dev); >> + >> dev_info(&client->dev, "imx274 : imx274 probe success !\n"); >> return 0; >> >> err_ctrls: >> v4l2_ctrl_handler_free(&imx274->ctrls.handler); >> +err_disable_rpm: >> + pm_runtime_disable(&client->dev); >> + pm_runtime_set_suspended(&client->dev); >> err_me: >> media_entity_cleanup(&sd->entity); >> err_regmap: >> @@ -1973,14 +2092,23 @@ static int imx274_remove(struct i2c_client *client) >> >> v4l2_async_unregister_subdev(sd); >> v4l2_ctrl_handler_free(&imx274->ctrls.handler); >> + >> + pm_runtime_disable(&client->dev); >> + pm_runtime_set_suspended(&client->dev); >> + >> media_entity_cleanup(&sd->entity); >> mutex_destroy(&imx274->lock); >> return 0; >> } >> >> +static const struct dev_pm_ops imx274_pm_ops = { >> + SET_RUNTIME_PM_OPS(imx274_power_off, imx274_power_on, NULL) >> +}; >> + >> static struct i2c_driver imx274_i2c_driver = { >> .driver = { >> .name = DRIVER_NAME, >> + .pm = &imx274_pm_ops, >> .of_match_table = imx274_of_id_table, >> }, >> .probe_new = imx274_probe, >> -- >> 2.7.4 >>
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