2020-03-13 21:13:42

by Prabhakar Mahadev Lad

[permalink] [raw]
Subject: [PATCH v3 2/4] media: i2c: ov5645: Switch to assigned-clock-rates

This patch switches to assigned-clock-rates for specifying the clock rate.
The clk-conf.c internally handles setting the clock rate when
assigned-clock-rates is passed.

The driver now sets the clock frequency only if the deprecated property
clock-frequency is defined instead assigned-clock-rates, this is to avoid
breakage with existing DT binaries.

Signed-off-by: Lad Prabhakar <[email protected]>
---
drivers/media/i2c/ov5645.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
index a6c17d1..4fbabf3 100644
--- a/drivers/media/i2c/ov5645.c
+++ b/drivers/media/i2c/ov5645.c
@@ -1055,6 +1055,7 @@ static int ov5645_probe(struct i2c_client *client)
struct device_node *endpoint;
struct ov5645 *ov5645;
u8 chip_id_high, chip_id_low;
+ bool set_clk = false;
unsigned int i;
u32 xclk_freq;
int ret;
@@ -1094,12 +1095,18 @@ static int ov5645_probe(struct i2c_client *client)
return PTR_ERR(ov5645->xclk);
}

- ret = of_property_read_u32(dev->of_node, "clock-frequency", &xclk_freq);
- if (ret) {
- dev_err(dev, "could not get xclk frequency\n");
- return ret;
+ /* check if deprecated property clock-frequency is defined */
+ ret = of_property_read_u32(dev->of_node, "clock-frequency",
+ &xclk_freq);
+ if (!ret) {
+ ret = clk_set_rate(ov5645->xclk, xclk_freq);
+ if (ret) {
+ dev_err(dev, "could not set xclk frequency\n");
+ return ret;
+ }
}

+ xclk_freq = clk_get_rate(ov5645->xclk);
/* external clock must be 24MHz, allow 1% tolerance */
if (xclk_freq < 23760000 || xclk_freq > 24240000) {
dev_err(dev, "external clock frequency %u is not supported\n",
@@ -1107,12 +1114,6 @@ static int ov5645_probe(struct i2c_client *client)
return -EINVAL;
}

- ret = clk_set_rate(ov5645->xclk, xclk_freq);
- if (ret) {
- dev_err(dev, "could not set xclk frequency\n");
- return ret;
- }
-
for (i = 0; i < OV5645_NUM_SUPPLIES; i++)
ov5645->supplies[i].supply = ov5645_supply_name[i];

--
2.7.4


2020-03-13 21:17:45

by Laurent Pinchart

[permalink] [raw]
Subject: Re: [PATCH v3 2/4] media: i2c: ov5645: Switch to assigned-clock-rates

Hi Prabakhar,

Thank you for the patch.

On Fri, Mar 13, 2020 at 09:12:32PM +0000, Lad Prabhakar wrote:
> This patch switches to assigned-clock-rates for specifying the clock rate.
> The clk-conf.c internally handles setting the clock rate when
> assigned-clock-rates is passed.
>
> The driver now sets the clock frequency only if the deprecated property
> clock-frequency is defined instead assigned-clock-rates, this is to avoid
> breakage with existing DT binaries.
>
> Signed-off-by: Lad Prabhakar <[email protected]>
> ---
> drivers/media/i2c/ov5645.c | 21 +++++++++++----------
> 1 file changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> index a6c17d1..4fbabf3 100644
> --- a/drivers/media/i2c/ov5645.c
> +++ b/drivers/media/i2c/ov5645.c
> @@ -1055,6 +1055,7 @@ static int ov5645_probe(struct i2c_client *client)
> struct device_node *endpoint;
> struct ov5645 *ov5645;
> u8 chip_id_high, chip_id_low;
> + bool set_clk = false;

This isn't used.

> unsigned int i;
> u32 xclk_freq;
> int ret;
> @@ -1094,12 +1095,18 @@ static int ov5645_probe(struct i2c_client *client)
> return PTR_ERR(ov5645->xclk);
> }
>
> - ret = of_property_read_u32(dev->of_node, "clock-frequency", &xclk_freq);
> - if (ret) {
> - dev_err(dev, "could not get xclk frequency\n");
> - return ret;
> + /* check if deprecated property clock-frequency is defined */
> + ret = of_property_read_u32(dev->of_node, "clock-frequency",
> + &xclk_freq);
> + if (!ret) {
> + ret = clk_set_rate(ov5645->xclk, xclk_freq);
> + if (ret) {
> + dev_err(dev, "could not set xclk frequency\n");
> + return ret;
> + }
> }
>
> + xclk_freq = clk_get_rate(ov5645->xclk);

I would move this line below the comment.

Reviewed-by: Laurent Pinchart <[email protected]>

> /* external clock must be 24MHz, allow 1% tolerance */
> if (xclk_freq < 23760000 || xclk_freq > 24240000) {
> dev_err(dev, "external clock frequency %u is not supported\n",
> @@ -1107,12 +1114,6 @@ static int ov5645_probe(struct i2c_client *client)
> return -EINVAL;
> }
>
> - ret = clk_set_rate(ov5645->xclk, xclk_freq);
> - if (ret) {
> - dev_err(dev, "could not set xclk frequency\n");
> - return ret;
> - }
> -
> for (i = 0; i < OV5645_NUM_SUPPLIES; i++)
> ov5645->supplies[i].supply = ov5645_supply_name[i];
>

--
Regards,

Laurent Pinchart

2020-03-13 21:22:36

by Prabhakar Mahadev Lad

[permalink] [raw]
Subject: RE: [PATCH v3 2/4] media: i2c: ov5645: Switch to assigned-clock-rates

Hi Laurent,

Thank you for the quick review.

> -----Original Message-----
> From: Laurent Pinchart <[email protected]>
> Sent: 13 March 2020 21:17
> To: Prabhakar Mahadev Lad <[email protected]>
> Cc: Mauro Carvalho Chehab <[email protected]>; Shawn Guo
> <[email protected]>; Sascha Hauer <[email protected]>;
> Pengutronix Kernel Team <[email protected]>; Rob Herring
> <[email protected]>; Mark Rutland <[email protected]>; Sakari
> Ailus <[email protected]>; NXP Linux Team <[email protected]>;
> Magnus Damm <[email protected]>; Ezequiel Garcia
> <[email protected]>; Geert Uytterhoeven <[email protected]>;
> [email protected]; [email protected]; linux-renesas-
> [email protected]; Fabio Estevam <[email protected]>; linux-
> [email protected]; [email protected]
> Subject: Re: [PATCH v3 2/4] media: i2c: ov5645: Switch to assigned-clock-
> rates
>
> Hi Prabakhar,
>
> Thank you for the patch.
>
> On Fri, Mar 13, 2020 at 09:12:32PM +0000, Lad Prabhakar wrote:
> > This patch switches to assigned-clock-rates for specifying the clock rate.
> > The clk-conf.c internally handles setting the clock rate when
> > assigned-clock-rates is passed.
> >
> > The driver now sets the clock frequency only if the deprecated
> > property clock-frequency is defined instead assigned-clock-rates, this
> > is to avoid breakage with existing DT binaries.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-
> [email protected]>
> > ---
> > drivers/media/i2c/ov5645.c | 21 +++++++++++----------
> > 1 file changed, 11 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> > index a6c17d1..4fbabf3 100644
> > --- a/drivers/media/i2c/ov5645.c
> > +++ b/drivers/media/i2c/ov5645.c
> > @@ -1055,6 +1055,7 @@ static int ov5645_probe(struct i2c_client *client)
> > struct device_node *endpoint;
> > struct ov5645 *ov5645;
> > u8 chip_id_high, chip_id_low;
> > +bool set_clk = false;
>
> This isn't used.
>
Argh! missed it.

> > unsigned int i;
> > u32 xclk_freq;
> > int ret;
> > @@ -1094,12 +1095,18 @@ static int ov5645_probe(struct i2c_client
> *client)
> > return PTR_ERR(ov5645->xclk);
> > }
> >
> > -ret = of_property_read_u32(dev->of_node, "clock-frequency",
> &xclk_freq);
> > -if (ret) {
> > -dev_err(dev, "could not get xclk frequency\n");
> > -return ret;
> > +/* check if deprecated property clock-frequency is defined */
> > +ret = of_property_read_u32(dev->of_node, "clock-frequency",
> > + &xclk_freq);
> > +if (!ret) {
> > +ret = clk_set_rate(ov5645->xclk, xclk_freq);
> > +if (ret) {
> > +dev_err(dev, "could not set xclk frequency\n");
> > +return ret;
> > +}
> > }
> >
> > +xclk_freq = clk_get_rate(ov5645->xclk);
>
> I would move this line below the comment.
>
Sure will do that.

Cheers,
--Prabhakar

> Reviewed-by: Laurent Pinchart <[email protected]>
>
> > /* external clock must be 24MHz, allow 1% tolerance */
> > if (xclk_freq < 23760000 || xclk_freq > 24240000) {
> > dev_err(dev, "external clock frequency %u is not
> supported\n", @@
> > -1107,12 +1114,6 @@ static int ov5645_probe(struct i2c_client *client)
> > return -EINVAL;
> > }
> >
> > -ret = clk_set_rate(ov5645->xclk, xclk_freq);
> > -if (ret) {
> > -dev_err(dev, "could not set xclk frequency\n");
> > -return ret;
> > -}
> > -
> > for (i = 0; i < OV5645_NUM_SUPPLIES; i++)
> > ov5645->supplies[i].supply = ov5645_supply_name[i];
> >
>
> --
> Regards,
>
> Laurent Pinchart


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