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Message-ID: <4e7e3080857b5822011734776de7456787dda546.camel@gmail.com>
Subject: Re: [PATCH v4 2/2] iio: frequency: adf4350: add clk provider
From: Nuno =?ISO-8859-1?Q?S=E1?= <noname.nuno@gmail.com>
To: Antoniu Miclaus <antoniu.miclaus@analog.com>, Lars-Peter Clausen
	 <lars@metafoo.de>, Michael Hennerich <Michael.Hennerich@analog.com>, 
 Jonathan Cameron
	 <jic23@kernel.org>, Rob Herring <robh@kernel.org>, Krzysztof Kozlowski
	 <krzk+dt@kernel.org>, Conor Dooley <conor+dt@kernel.org>, 
	linux-iio@vger.kernel.org, devicetree@vger.kernel.org, 
	linux-kernel@vger.kernel.org
Date: Fri, 14 Jun 2024 17:23:37 +0200
In-Reply-To: <20240612130232.7692-2-antoniu.miclaus@analog.com>
References: <20240612130232.7692-1-antoniu.miclaus@analog.com>
	 <20240612130232.7692-2-antoniu.miclaus@analog.com>
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On Wed, 2024-06-12 at 16:02 +0300, Antoniu Miclaus wrote:
> Add clk provider feature for the adf4350.
>=20
> Even though the driver was sent as an IIO driver in most cases the
> device is actually seen as a clock provider.
>=20
> This patch aims to cover actual usecases requested by users in order to
> completely control the output frequencies from userspace.
>=20
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
> changes in v4:
> =C2=A0- rename macro to `to_adf4350_state`
> =C2=A0- do not expose ADF4350_FREQ and ADF4350_FREQ_REFIN if driver is us=
ed as clk
> =C2=A0=C2=A0 provider.
> =C2=A0- initialize flags with CLK_SET_RATE_PARENT
> =C2=A0drivers/iio/frequency/adf4350.c | 134 +++++++++++++++++++++++++++++=
++-
> =C2=A01 file changed, 133 insertions(+), 1 deletion(-)
>=20
> diff --git a/drivers/iio/frequency/adf4350.c b/drivers/iio/frequency/adf4=
350.c
> index 4abf80f75ef5..8309ddfca9af 100644
> --- a/drivers/iio/frequency/adf4350.c
> +++ b/drivers/iio/frequency/adf4350.c
> @@ -19,6 +19,7 @@
> =C2=A0#include <linux/gpio/consumer.h>
> =C2=A0#include <asm/div64.h>
> =C2=A0#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> =C2=A0
> =C2=A0#include <linux/iio/iio.h>
> =C2=A0#include <linux/iio/sysfs.h>
> @@ -36,6 +37,9 @@ struct adf4350_state {
> =C2=A0	struct gpio_desc		*lock_detect_gpiod;
> =C2=A0	struct adf4350_platform_data	*pdata;
> =C2=A0	struct clk			*clk;
> +	struct clk			*clkout;
> +	const char			*clk_out_name;
> +	struct clk_hw			hw;
> =C2=A0	unsigned long			clkin;
> =C2=A0	unsigned long			chspc; /* Channel Spacing */
> =C2=A0	unsigned long			fpfd; /* Phase Frequency Detector */
> @@ -61,6 +65,8 @@ struct adf4350_state {
> =C2=A0	__be32				val __aligned(IIO_DMA_MINALIGN);
> =C2=A0};
> =C2=A0
> +#define to_adf4350_state(_hw) container_of(_hw, struct adf4350_state, hw=
)
> +
> =C2=A0static struct adf4350_platform_data default_pdata =3D {
> =C2=A0	.channel_spacing =3D 10000,
> =C2=A0	.r2_user_settings =3D ADF4350_REG2_PD_POLARITY_POS |
> @@ -370,6 +376,12 @@ static const struct iio_chan_spec_ext_info adf4350_e=
xt_info[]
> =3D {
> =C2=A0	{ },
> =C2=A0};
> =C2=A0
> +static const struct iio_chan_spec_ext_info adf4350_clk_ext_info[] =3D {
> +	_ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
> +	_ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
> +	{ },

Do we really need powerdown? Dunno :). I would expect one of unprepare/disa=
ble to
take care of that. Moreover, imagine userspace powers down the device while=
 an in
kernel consumer was using it? Not cool right ehhe?

Even the frequency_resolution is arguable as that is also a DT property but=
 to keep
consistency why not? That one I can live with...

Also note that you're still not including the clock maintainers in the loop=
.

- Nuno S=C3=A1