On 11/11/2016 02:48 PM, Laurent Pinchart wrote:
> Hi Hans,
>
> On Friday 11 Nov 2016 14:21:22 Hans Verkuil wrote:
>> On 11/09/2016 04:44 PM, Ramesh Shanmugasundaram wrote:
>>> This patch adds driver support for MAX2175 chip. This is Maxim
>>> Integrated's RF to Bits tuner front end chip designed for software-defined
>>> radio solutions. This driver exposes the tuner as a sub-device instance
>>> with standard and custom controls to configure the device.
>>>
>>> Signed-off-by: Ramesh Shanmugasundaram
>>> <ramesh.shanmugasundaram@xxxxxxxxxxxxxx> ---
>>>
>>> .../devicetree/bindings/media/i2c/max2175.txt | 61 +
>>> drivers/media/i2c/Kconfig | 4 +
>>> drivers/media/i2c/Makefile | 2 +
>>> drivers/media/i2c/max2175/Kconfig | 8 +
>>> drivers/media/i2c/max2175/Makefile | 4 +
>>> drivers/media/i2c/max2175/max2175.c | 1558 +++++++++++++++
>>> drivers/media/i2c/max2175/max2175.h | 108 ++
>>> 7 files changed, 1745 insertions(+)
>>> create mode 100644
>>> Documentation/devicetree/bindings/media/i2c/max2175.txt
>>> create mode 100644 drivers/media/i2c/max2175/Kconfig
>>> create mode 100644 drivers/media/i2c/max2175/Makefile
>>> create mode 100644 drivers/media/i2c/max2175/max2175.c
>>> create mode 100644 drivers/media/i2c/max2175/max2175.h
>>
>> <snip>
>>
>>> diff --git a/drivers/media/i2c/max2175/max2175.c
>>> b/drivers/media/i2c/max2175/max2175.c new file mode 100644
>>> index 0000000..ec45b52
>>> --- /dev/null
>>> +++ b/drivers/media/i2c/max2175/max2175.c
>>> @@ -0,0 +1,1558 @@
>>
>> <snip>
>>
>>> +/* Read/Write bit(s) on top of regmap */
>>> +static int max2175_read(struct max2175 *ctx, u8 idx, u8 *val)
>>> +{
>>> + u32 regval;
>>> + int ret = regmap_read(ctx->regmap, idx, ®val);
>>> +
>>> + if (ret)
>>> + v4l2_err(ctx->client, "read ret(%d): idx 0x%02x\n", ret, idx);
>
> By the way, I think I've seen a proposal to get rid of v4l2_err() in favour of
> dev_err(), was I dreaming or should this patch use dev_err() already ?
I haven't seen anything, but I may have missed it. I haven't been on top of the
mailinglist lately. I'm fine with both.
>
>>> +
>>> + *val = regval;
>>
>> Does regmap_read initialize regval even if it returns an error? If not,
>> then I would initialize regval to 0 to prevent *val being uninitialized.
>
> Better than that the error should be propagated to the caller and handled.
>
>>> + return ret;
>>> +}
>
> [snip]
>
>>> +static int max2175_band_from_freq(u32 freq)
>>> +{
>>> + if (freq >= 144000 && freq <= 26100000)
>>> + return MAX2175_BAND_AM;
>>> + else if (freq >= 65000000 && freq <= 108000000)
>>> + return MAX2175_BAND_FM;
>>> + else
>>
>> No need for these 'else' keywords.
>
> Indeed by in my opinion they improve readability :-)
>
>>> + return MAX2175_BAND_VHF;
>>> +}
>
> [snip]
>
>>> +static const struct v4l2_ctrl_config max2175_na_rx_mode = {
>>> + .ops = &max2175_ctrl_ops,
>>> + .id = V4L2_CID_MAX2175_RX_MODE,
>>> + .name = "RX MODE",
>>> + .type = V4L2_CTRL_TYPE_MENU,
>>> + .max = ARRAY_SIZE(max2175_ctrl_na_rx_modes) - 1,
>>> + .def = 0,
>>> + .qmenu = max2175_ctrl_na_rx_modes,
>>> +};
>>
>> Please document all these controls better. This is part of the public API,
>> so you need to give more information what this means exactly.
>
> Should that go to Documentation/media/v4l-drivers/ ? If so "[PATCH v4 3/4]
> v4l: Add Renesas R-Car FDP1 Driver" can be used as an example.
I think that's the preferred place going forward. But a comment should be
added here pointing to that file so there is a better chance of keeping
the doc and code in sync.
>
> [snip]
>
Hans
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