Re: [PATCH v2 4/7] media: ov5693: move hw cfg functions into ov5693_check_hwcfg
From: Daniel Scally
Date: Thu Jun 30 2022 - 06:27:18 EST
Hey
On 29/06/2022 09:16, Jacopo Mondi wrote:
> Hi Tommaso,
>
> On Mon, Jun 27, 2022 at 05:04:50PM +0200, Tommaso Merciai wrote:
>> Move hw configuration functions into ov5693_check_hwcfg. This is done to
>> separe the code that handle the hw cfg from probe in a clean way
> s/separe/separate/
>
> You also seem to change the logic of the clk handling, please mention
> this in the commit message, otherwise one could be fooled into
> thinking you're only moving code around with no functional changes...
>
>> Signed-off-by: Tommaso Merciai <tommaso.merciai@xxxxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/media/i2c/ov5693.c | 53 +++++++++++++++++++++++---------------
>> 1 file changed, 32 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/media/i2c/ov5693.c b/drivers/media/i2c/ov5693.c
>> index d2adc5513a21..d5a934ace597 100644
>> --- a/drivers/media/i2c/ov5693.c
>> +++ b/drivers/media/i2c/ov5693.c
>> @@ -1348,6 +1348,38 @@ static int ov5693_check_hwcfg(struct ov5693_device *ov5693)
>> struct fwnode_handle *endpoint;
>> unsigned int i;
>> int ret;
>> + u32 xvclk_rate;
> nit: move it up to maintain reverse-xmas-tree order (I know, it's an
> annoying comment, but since variables are already declared in this order..)
>
>> +
>> + ov5693->xvclk = devm_clk_get(ov5693->dev, "xvclk");
> Isn't this broken ?
>
> if you use ov5693->xvclk to identify the ACPI vs OF use case shouldn't
> you use the get_optionl() version ? Otherwise in the ACPI case you will have
> -ENOENT if there's not 'xvclk' property and bail out.
>
> Unless my understanding is wrong on ACPI we have "clock-frequency" and
> on OF "xvclk" with an "assigned-clock-rates",
>
> Dan you upstreamed this driver and I assume it was tested on ACPI ?
> Can you clarify how this worked for you, as it seems the original code
> wanted a mandatory "xvclk" ? Are there ACPI tables with an actual
> 'xvclk' property ?
Sorry - late answer, but when I wrote this although it's ostensibly for
an ACPI platform, it's actually only tested with the IPU3 platforms
which work in a _weird_ way. The fix we eventually came to was to create
through the int3472-discrete driver clocks and regulators through the
normal frameworks that a dt platform would expect to consume, so even
though the devices are enumerated through ACPI, the clock/regulator
parts really work more like a dt platform.
You're right that it needs to be get_optional() here, but with that
added I think this is fine - I tested it last night and it works ok for me.
>
>> + if (IS_ERR(ov5693->xvclk))
>> + return dev_err_probe(ov5693->dev, PTR_ERR(ov5693->xvclk),
>> + "failed to get xvclk: %ld\n",
>> + PTR_ERR(ov5693->xvclk));
>> +
>> + if (ov5693->xvclk) {
>> + xvclk_rate = clk_get_rate(ov5693->xvclk);
>> + } else {
>> + ret = fwnode_property_read_u32(fwnode, "clock-frequency",
>> + &xvclk_rate);
>> +
>> + if (ret) {
>> + dev_err(ov5693->dev, "can't get clock frequency");
>> + return ret;
>> + }
>> + }
>> +
>> + if (xvclk_rate != OV5693_XVCLK_FREQ)
>> + dev_warn(ov5693->dev, "Found clk freq %u, expected %u\n",
>> + xvclk_rate, OV5693_XVCLK_FREQ);
>> +
>> + ret = ov5693_configure_gpios(ov5693);
>> + if (ret)
>> + return ret;
>> +
>> + ret = ov5693_get_regulators(ov5693);
>> + if (ret)
>> + return dev_err_probe(ov5693->dev, ret,
>> + "Error fetching regulators\n");
>>
>> endpoint = fwnode_graph_get_next_endpoint(fwnode, NULL);
>> if (!endpoint)
>> @@ -1390,7 +1422,6 @@ static int ov5693_check_hwcfg(struct ov5693_device *ov5693)
>> static int ov5693_probe(struct i2c_client *client)
>> {
>> struct ov5693_device *ov5693;
>> - u32 xvclk_rate;
>> int ret = 0;
>>
>> ov5693 = devm_kzalloc(&client->dev, sizeof(*ov5693), GFP_KERNEL);
>> @@ -1408,26 +1439,6 @@ static int ov5693_probe(struct i2c_client *client)
>>
>> v4l2_i2c_subdev_init(&ov5693->sd, client, &ov5693_ops);
>>
>> - ov5693->xvclk = devm_clk_get(&client->dev, "xvclk");
>> - if (IS_ERR(ov5693->xvclk)) {
>> - dev_err(&client->dev, "Error getting clock\n");
>> - return PTR_ERR(ov5693->xvclk);
>> - }
>> -
>> - xvclk_rate = clk_get_rate(ov5693->xvclk);
>> - if (xvclk_rate != OV5693_XVCLK_FREQ)
>> - dev_warn(&client->dev, "Found clk freq %u, expected %u\n",
>> - xvclk_rate, OV5693_XVCLK_FREQ);
>> -
>> - ret = ov5693_configure_gpios(ov5693);
>> - if (ret)
>> - return ret;
>> -
>> - ret = ov5693_get_regulators(ov5693);
>> - if (ret)
>> - return dev_err_probe(&client->dev, ret,
>> - "Error fetching regulators\n");
>> -
>> ov5693->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>> ov5693->pad.flags = MEDIA_PAD_FL_SOURCE;
>> ov5693->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
>> --
>> 2.25.1
>>