Hi Jacopo
Thanks for the review
On Fri, 2 Jun 2023 at 14:23, Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx> wrote:
>
> Hi Dave
>
> On Tue, May 30, 2023 at 06:29:48PM +0100, Dave Stevenson wrote:
> > Extends the driver to also support 2 data lanes.
> > Frame rates are obviously more restricted on 2 lanes, but some
> > hardware simply hasn't wired more up.
> >
> > Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> > ---
> > drivers/media/i2c/imx258.c | 211 ++++++++++++++++++++++++++++++++-----
> > 1 file changed, 187 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
> > index d40521f9a3c6..433dff7f1fa0 100644
> > --- a/drivers/media/i2c/imx258.c
> > +++ b/drivers/media/i2c/imx258.c
> > @@ -86,13 +86,17 @@ struct imx258_reg_list {
> > const struct imx258_reg *regs;
> > };
> >
> > +#define IMX258_LANE_CONFIGS 2
> > +#define IMX258_2_LANE_MODE 0
> > +#define IMX258_4_LANE_MODE 1
> > +
>
> nit: This might be better expressed as an enum...
Will do. It's always a toss up between the two.
> > /* Link frequency config */
> > struct imx258_link_freq_config {
> > u64 link_frequency;
> > u32 pixels_per_line;
> >
> > /* PLL registers for this link frequency */
> > - struct imx258_reg_list reg_list;
> > + struct imx258_reg_list reg_list[IMX258_LANE_CONFIGS];
> > };
> >
> > /* Mode : resolution and related config&values */
> > @@ -112,8 +116,30 @@ struct imx258_mode {
> > struct imx258_reg_list reg_list;
> > };
> >
> > -/* 4208x3120 needs 1267Mbps/lane, 4 lanes */
> > -static const struct imx258_reg mipi_1267mbps_19_2mhz[] = {
> > +/* 4208x3120 needs 1267Mbps/lane, 4 lanes. Use that rate on 2 lanes as well */
>
> I might be missing how the same link freq (and thus lane bandwidth)
> gives the same frame rate on 4 and 2 data lanes setup..
>
> I get a total bandwidth with default VTS and PPL for 10bpp mode at 30
> fps of
>
> vts * ppl * bpp * fps =
> 3152 * 5352 * 10 * 30 = 5060851200 bit/sec
>
> The resulting lane bandwidth for 4 lanes is
> 1.265.212.800 which ~= 1267 Mbps/lane you have above
> and results in a link frequency of
> 632606400 which matches your 634MHz/636MHz
>
> With 2 lanes either you double the bandwidth or you halve the frame
> rate. Seeing that now link_freq_to_pixel_rate() will give you a *2
> result in 4 lanes configuration, I presume full res mode runs at 15FPS
> on 2 lanes ? If that's the case, should you remove '30FPS' from the
> VTS default value defines ?
The comment here doesn't specify a frame rate, although admittedly it
is ambiguously worded.
I'll reword to:
4208x3120 @ 30fps needs 1267Mbps/lane when using 4 lanes.
To avoid further computation of clock settings, adopt the same per
lane data rate when using 2 lanes, thus allowing a maximum of 15fps.
> > +static const struct imx258_reg mipi_1267mbps_19_2mhz_2l[] = {
> > + { 0x0136, 0x13 },
> > + { 0x0137, 0x33 },
> > + { 0x0301, 0x0A },
> > + { 0x0303, 0x02 },
> > + { 0x0305, 0x03 },
> > + { 0x0306, 0x00 },
> > + { 0x0307, 0xC6 },
> > + { 0x0309, 0x0A },
> > + { 0x030B, 0x01 },
> > + { 0x030D, 0x02 },
> > + { 0x030E, 0x00 },
> > + { 0x030F, 0xD8 },
> > + { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x01 },
> > + { 0x0820, 0x09 },
> > + { 0x0821, 0xa6 },
> > + { 0x0822, 0x66 },
> > + { 0x0823, 0x66 },
> > +};
> > +
> > +static const struct imx258_reg mipi_1267mbps_19_2mhz_4l[] = {
> > { 0x0136, 0x13 },
> > { 0x0137, 0x33 },
> > { 0x0301, 0x05 },
> > @@ -127,16 +153,18 @@ static const struct imx258_reg mipi_1267mbps_19_2mhz[] = {
> > { 0x030E, 0x00 },
> > { 0x030F, 0xD8 },
> > { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x03 },
> > { 0x0820, 0x13 },
> > { 0x0821, 0x4C },
> > { 0x0822, 0xCC },
> > { 0x0823, 0xCC },
> > };
> >
> > -static const struct imx258_reg mipi_1272mbps_24mhz[] = {
> > +static const struct imx258_reg mipi_1272mbps_24mhz_2l[] = {
> > { 0x0136, 0x18 },
> > { 0x0137, 0x00 },
> > - { 0x0301, 0x05 },
> > + { 0x0301, 0x0a },
> > { 0x0303, 0x02 },
> > { 0x0305, 0x04 },
> > { 0x0306, 0x00 },
> > @@ -147,13 +175,59 @@ static const struct imx258_reg mipi_1272mbps_24mhz[] = {
> > { 0x030E, 0x00 },
> > { 0x030F, 0xD8 },
> > { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x01 },
> > { 0x0820, 0x13 },
> > { 0x0821, 0x4C },
> > { 0x0822, 0xCC },
> > { 0x0823, 0xCC },
> > };
> >
> > -static const struct imx258_reg mipi_640mbps_19_2mhz[] = {
> > +static const struct imx258_reg mipi_1272mbps_24mhz_4l[] = {
> > + { 0x0136, 0x18 },
> > + { 0x0137, 0x00 },
> > + { 0x0301, 0x05 },
> > + { 0x0303, 0x02 },
> > + { 0x0305, 0x04 },
> > + { 0x0306, 0x00 },
> > + { 0x0307, 0xD4 },
> > + { 0x0309, 0x0A },
> > + { 0x030B, 0x01 },
> > + { 0x030D, 0x02 },
> > + { 0x030E, 0x00 },
> > + { 0x030F, 0xD8 },
> > + { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x03 },
> > + { 0x0820, 0x13 },
> > + { 0x0821, 0xE0 },
> > + { 0x0822, 0x00 },
> > + { 0x0823, 0x00 },
> > +};
> > +
> > +static const struct imx258_reg mipi_640mbps_19_2mhz_2l[] = {
> > + { 0x0136, 0x13 },
> > + { 0x0137, 0x33 },
> > + { 0x0301, 0x05 },
> > + { 0x0303, 0x02 },
> > + { 0x0305, 0x03 },
> > + { 0x0306, 0x00 },
> > + { 0x0307, 0x64 },
> > + { 0x0309, 0x0A },
> > + { 0x030B, 0x01 },
> > + { 0x030D, 0x02 },
> > + { 0x030E, 0x00 },
> > + { 0x030F, 0xD8 },
> > + { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x01 },
> > + { 0x0820, 0x05 },
> > + { 0x0821, 0x00 },
> > + { 0x0822, 0x00 },
> > + { 0x0823, 0x00 },
> > +};
> > +
> > +static const struct imx258_reg mipi_640mbps_19_2mhz_4l[] = {
> > { 0x0136, 0x13 },
> > { 0x0137, 0x33 },
> > { 0x0301, 0x05 },
> > @@ -167,13 +241,37 @@ static const struct imx258_reg mipi_640mbps_19_2mhz[] = {
> > { 0x030E, 0x00 },
> > { 0x030F, 0xD8 },
> > { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x03 },
> > { 0x0820, 0x0A },
> > { 0x0821, 0x00 },
> > { 0x0822, 0x00 },
> > { 0x0823, 0x00 },
> > };
> >
> > -static const struct imx258_reg mipi_642mbps_24mhz[] = {
> > +static const struct imx258_reg mipi_642mbps_24mhz_2l[] = {
> > + { 0x0136, 0x18 },
> > + { 0x0137, 0x00 },
> > + { 0x0301, 0x0A },
> > + { 0x0303, 0x02 },
> > + { 0x0305, 0x04 },
> > + { 0x0306, 0x00 },
> > + { 0x0307, 0x6B },
> > + { 0x0309, 0x0A },
> > + { 0x030B, 0x01 },
> > + { 0x030D, 0x02 },
> > + { 0x030E, 0x00 },
> > + { 0x030F, 0xD8 },
> > + { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x01 },
> > + { 0x0820, 0x0A },
> > + { 0x0821, 0x00 },
> > + { 0x0822, 0x00 },
> > + { 0x0823, 0x00 },
> > +};
> > +
> > +static const struct imx258_reg mipi_642mbps_24mhz_4l[] = {
> > { 0x0136, 0x18 },
> > { 0x0137, 0x00 },
> > { 0x0301, 0x05 },
> > @@ -187,6 +285,8 @@ static const struct imx258_reg mipi_642mbps_24mhz[] = {
> > { 0x030E, 0x00 },
> > { 0x030F, 0xD8 },
> > { 0x0310, 0x00 },
> > +
> > + { 0x0114, 0x03 },
> > { 0x0820, 0x0A },
> > { 0x0821, 0x00 },
> > { 0x0822, 0x00 },
> > @@ -241,7 +341,6 @@ static const struct imx258_reg mode_common_regs[] = {
> > { 0x5F05, 0xED },
> > { 0x0112, 0x0A },
> > { 0x0113, 0x0A },
> > - { 0x0114, 0x03 },
> > { 0x0342, 0x14 },
> > { 0x0343, 0xE8 },
> > { 0x0344, 0x00 },
> > @@ -360,11 +459,13 @@ enum {
> >
> > /*
> > * pixel_rate = link_freq * data-rate * nr_of_lanes / bits_per_sample
> > - * data rate => double data rate; number of lanes => 4; bits per pixel => 10
> > + * data rate => double data rate;
> > + * number of lanes => (configurable 2 or 4);
> > + * bits per pixel => 10
> > */
> > -static u64 link_freq_to_pixel_rate(u64 f)
> > +static u64 link_freq_to_pixel_rate(u64 f, unsigned int nlanes)
> > {
> > - f *= 2 * 4;
> > + f *= 2 * nlanes;
> > do_div(f, 10);
> >
> > return f;
> > @@ -394,15 +495,27 @@ static const struct imx258_link_freq_config link_freq_configs_19_2[] = {
> > [IMX258_LINK_FREQ_1267MBPS] = {
> > .pixels_per_line = IMX258_PPL_DEFAULT,
> > .reg_list = {
> > - .num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz),
> > - .regs = mipi_1267mbps_19_2mhz,
> > + [IMX258_2_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz_2l),
> > + .regs = mipi_1267mbps_19_2mhz_2l,
> > + },
> > + [IMX258_4_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz_4l),
> > + .regs = mipi_1267mbps_19_2mhz_4l,
> > + },
> > }
> > },
> > [IMX258_LINK_FREQ_640MBPS] = {
> > .pixels_per_line = IMX258_PPL_DEFAULT,
> > .reg_list = {
> > - .num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz),
> > - .regs = mipi_640mbps_19_2mhz,
> > + [IMX258_2_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz_2l),
> > + .regs = mipi_640mbps_19_2mhz_2l,
> > + },
> > + [IMX258_4_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz_4l),
> > + .regs = mipi_640mbps_19_2mhz_4l,
> > + },
> > }
> > },
> > };
> > @@ -411,15 +524,27 @@ static const struct imx258_link_freq_config link_freq_configs_24[] = {
> > [IMX258_LINK_FREQ_1267MBPS] = {
> > .pixels_per_line = IMX258_PPL_DEFAULT,
> > .reg_list = {
> > - .num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz),
> > - .regs = mipi_1272mbps_24mhz,
> > + [IMX258_2_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz_2l),
> > + .regs = mipi_1272mbps_24mhz_2l,
> > + },
> > + [IMX258_4_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz_4l),
> > + .regs = mipi_1272mbps_24mhz_4l,
> > + },
> > }
> > },
> > [IMX258_LINK_FREQ_640MBPS] = {
> > .pixels_per_line = IMX258_PPL_DEFAULT,
> > .reg_list = {
> > - .num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz),
> > - .regs = mipi_642mbps_24mhz,
> > + [IMX258_2_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz_2l),
> > + .regs = mipi_642mbps_24mhz_2l,
> > + },
> > + [IMX258_4_LANE_MODE] = {
> > + .num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz_4l),
> > + .regs = mipi_642mbps_24mhz_4l,
> > + },
> > }
> > },
> > };
> > @@ -478,6 +603,7 @@ struct imx258 {
> >
> > const struct imx258_link_freq_config *link_freq_configs;
> > const s64 *link_freq_menu_items;
> > + unsigned int nlanes;
> >
> > /*
> > * Mutex for serialized access:
> > @@ -787,7 +913,7 @@ static int imx258_set_pad_format(struct v4l2_subdev *sd,
> > __v4l2_ctrl_s_ctrl(imx258->link_freq, mode->link_freq_index);
> >
> > link_freq = imx258->link_freq_menu_items[mode->link_freq_index];
> > - pixel_rate = link_freq_to_pixel_rate(link_freq);
> > + pixel_rate = link_freq_to_pixel_rate(link_freq, imx258->nlanes);
> > __v4l2_ctrl_s_ctrl_int64(imx258->pixel_rate, pixel_rate);
> > /* Update limits and set FPS to default */
> > vblank_def = imx258->cur_mode->vts_def -
> > @@ -816,11 +942,13 @@ static int imx258_start_streaming(struct imx258 *imx258)
> > {
> > struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
> > const struct imx258_reg_list *reg_list;
> > + const struct imx258_link_freq_config *link_freq_cfg;
> > int ret, link_freq_index;
> >
> > /* Setup PLL */
> > link_freq_index = imx258->cur_mode->link_freq_index;
> > - reg_list = &imx258->link_freq_configs[link_freq_index].reg_list;
> > + link_freq_cfg = &imx258->link_freq_configs[link_freq_index];
> > + reg_list = &link_freq_cfg->reg_list[imx258->nlanes == 2 ? 0 : 1];
> > ret = imx258_write_regs(imx258, reg_list->regs, reg_list->num_of_regs);
> > if (ret) {
> > dev_err(&client->dev, "%s failed to set plls\n", __func__);
> > @@ -1074,9 +1202,11 @@ static int imx258_init_controls(struct imx258 *imx258)
> > vflip->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >
> > pixel_rate_max =
> > - link_freq_to_pixel_rate(imx258->link_freq_menu_items[0]);
> > + link_freq_to_pixel_rate(imx258->link_freq_menu_items[0],
> > + imx258->nlanes);
> > pixel_rate_min =
> > - link_freq_to_pixel_rate(imx258->link_freq_menu_items[1]);
> > + link_freq_to_pixel_rate(imx258->link_freq_menu_items[1],
> > + imx258->nlanes);
> > /* By default, PIXEL_RATE is read only */
> > imx258->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops,
> > V4L2_CID_PIXEL_RATE,
> > @@ -1174,6 +1304,10 @@ static int imx258_get_regulators(struct imx258 *imx258,
> > static int imx258_probe(struct i2c_client *client)
> > {
> > struct imx258 *imx258;
> > + struct fwnode_handle *endpoint;
> > + struct v4l2_fwnode_endpoint ep = {
> > + .bus_type = V4L2_MBUS_CSI2_DPHY
> > + };
> > int ret;
> > u32 val = 0;
> >
> > @@ -1216,13 +1350,38 @@ static int imx258_probe(struct i2c_client *client)
> > return -EINVAL;
> > }
> >
> > + endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev), NULL);
> > + if (!endpoint) {
> > + dev_err(&client->dev, "Endpoint node not found\n");
> > + return -EINVAL;
> > + }
> > +
> > + ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);
> > + fwnode_handle_put(endpoint);
> > + if (ret == -ENXIO) {
>
> Doesn't the core warns you already ? Anywy, doesn't hurt I suppose
It looks to me like it's a pr_debug, so not apparently.
https://elixir.bootlin.com/linux/latest/source/drivers/media/v4l2-core/v4l2-fwnode.c#L443
There's no real need to differentiate why it failed here, so I'll
combine the two error cases and include the error code.
> > + dev_err(&client->dev, "Unsupported bus type, should be CSI2\n");
> > + goto error_endpoint_poweron;
> > + } else if (ret) {
> > + dev_err(&client->dev, "Parsing endpoint node failed\n");
> > + goto error_endpoint_poweron;
>
> It's a pretty peculiar name :) Why not 'error_endpoint_free' ?
It's been a while since I originally wrote this. Probably because it's
called if either the endpoint parsing fails, or if power_on fails.
I'll rename it as you suggest.
> Anyway, if parsing fails, I don't think you need to v4l2_fwnode_endpoint_free()
> as the core should take care of doing so.
Yes, it looks like it does, so I can just return here.
I still need the error path should the number of lanes be invalid, or
imx258_power_on fails, just not here.
> > + }
> > +
> > + /* Get number of data lanes */
> > + imx258->nlanes = ep.bus.mipi_csi2.num_data_lanes;
> > + if (imx258->nlanes != 2 && imx258->nlanes != 4) {
> > + dev_err(&client->dev, "Invalid data lanes: %u\n",
> > + imx258->nlanes);
> > + ret = -EINVAL;
> > + goto error_endpoint_poweron;
> > + }
> > +
> > /* Initialize subdev */
> > v4l2_i2c_subdev_init(&imx258->sd, client, &imx258_subdev_ops);
> >
> > /* Will be powered off via pm_runtime_idle */
> > ret = imx258_power_on(&client->dev);
> > if (ret)
> > - return ret;
> > + goto error_endpoint_poweron;
> >
> > /* Check module identity */
> > ret = imx258_identify_module(imx258);
> > @@ -1255,6 +1414,7 @@ static int imx258_probe(struct i2c_client *client)
> > pm_runtime_set_active(&client->dev);
> > pm_runtime_enable(&client->dev);
> > pm_runtime_idle(&client->dev);
> > + v4l2_fwnode_endpoint_free(&endpoint);
>
> Do you need to free in _remove() too ?
This is the success path at the end of _probe. We don't need the
endpoint after this, and it's a local to this function, therefore
cleaning up here.
As noted earlier, this should be:
v4l2_fwnode_endpoint_free(&ep);
Thanks
Dave
> >
> > return 0;
> >
> > @@ -1267,6 +1427,9 @@ static int imx258_probe(struct i2c_client *client)
> > error_identify:
> > imx258_power_off(&client->dev);
> >
> > +error_endpoint_poweron:
> > + v4l2_fwnode_endpoint_free(&ep);
> > +
> > return ret;
> > }
> >
> > --
> > 2.25.1
> >
