Re: [PATCH v8 06/18] media: qcom: camss: Add support for PHY API devices
From: Christopher Obbard
Date: Fri Feb 27 2026 - 17:05:08 EST
Hi Bryan,
On Wed, 2026-02-25 at 15:11 +0000, Bryan O'Donoghue wrote:
> Add the ability to use a PHY pointer which interacts with the standard PHY
> API.
>
> In the first instance the code will try to use the new PHY interface. If no
> PHYs are present in the DT then the legacy method will be attempted.
>
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Reviewed-by: Christopher Obbard <christopher.obbard@xxxxxxxxxx>
Tested-by: Christopher Obbard <christopher.obbard@xxxxxxxxxx>
> ---
> drivers/media/platform/qcom/camss/Kconfig | 1 +
> drivers/media/platform/qcom/camss/camss-csiphy.c | 185 +++++++++++++++++++++--
> drivers/media/platform/qcom/camss/camss-csiphy.h | 7 +
> drivers/media/platform/qcom/camss/camss.c | 72 +++++++--
> 4 files changed, 235 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/camss/Kconfig b/drivers/media/platform/qcom/camss/Kconfig
> index 4eda48cb1adf0..1edc5e5a1829e 100644
> --- a/drivers/media/platform/qcom/camss/Kconfig
> +++ b/drivers/media/platform/qcom/camss/Kconfig
> @@ -7,3 +7,4 @@ config VIDEO_QCOM_CAMSS
> select VIDEO_V4L2_SUBDEV_API
> select VIDEOBUF2_DMA_SG
> select V4L2_FWNODE
> + select PHY_QCOM_MIPI_CSI2
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.c b/drivers/media/platform/qcom/camss/camss-csiphy.c
> index 62623393f4144..59564284fd270 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.c
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.c
> @@ -7,12 +7,14 @@
> * Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
> * Copyright (C) 2016-2018 Linaro Ltd.
> */
> +#include <dt-bindings/phy/phy.h>
> #include <linux/clk.h>
> #include <linux/delay.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/of.h>
> +#include <linux/phy/phy.h>
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <media/media-entity.h>
> @@ -131,10 +133,10 @@ static u8 csiphy_get_bpp(const struct csiphy_format_info *formats,
> }
>
> /*
> - * csiphy_set_clock_rates - Calculate and set clock rates on CSIPHY module
> + * csiphy_set_clock_rates_legacy - Calculate and set clock rates on CSIPHY module
> * @csiphy: CSIPHY device
> */
> -static int csiphy_set_clock_rates(struct csiphy_device *csiphy)
> +static int csiphy_set_clock_rates_legacy(struct csiphy_device *csiphy)
> {
> struct device *dev = csiphy->camss->dev;
> s64 link_freq;
> @@ -200,7 +202,7 @@ static int csiphy_set_clock_rates(struct csiphy_device *csiphy)
> *
> * Return 0 on success or a negative error code otherwise
> */
> -static int csiphy_set_power(struct v4l2_subdev *sd, int on)
> +static int csiphy_set_power_legacy(struct v4l2_subdev *sd, int on)
> {
> struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
> struct device *dev = csiphy->camss->dev;
> @@ -219,7 +221,7 @@ static int csiphy_set_power(struct v4l2_subdev *sd, int on)
> return ret;
> }
>
> - ret = csiphy_set_clock_rates(csiphy);
> + ret = csiphy_set_clock_rates_legacy(csiphy);
> if (ret < 0) {
> regulator_bulk_disable(csiphy->num_supplies,
> csiphy->supplies);
> @@ -254,7 +256,7 @@ static int csiphy_set_power(struct v4l2_subdev *sd, int on)
> }
>
> /*
> - * csiphy_stream_on - Enable streaming on CSIPHY module
> + * csiphy_stream_on_legacy - Enable streaming on CSIPHY module
> * @csiphy: CSIPHY device
> *
> * Helper function to enable streaming on CSIPHY module.
> @@ -262,7 +264,7 @@ static int csiphy_set_power(struct v4l2_subdev *sd, int on)
> *
> * Return 0 on success or a negative error code otherwise
> */
> -static int csiphy_stream_on(struct csiphy_device *csiphy)
> +static int csiphy_stream_on_legacy(struct csiphy_device *csiphy)
> {
> struct csiphy_config *cfg = &csiphy->cfg;
> s64 link_freq;
> @@ -306,11 +308,86 @@ static int csiphy_stream_on(struct csiphy_device *csiphy)
> *
> * Helper function to disable streaming on CSIPHY module
> */
> -static void csiphy_stream_off(struct csiphy_device *csiphy)
> +static void csiphy_stream_off_legacy(struct csiphy_device *csiphy)
> {
> csiphy->res->hw_ops->lanes_disable(csiphy, &csiphy->cfg);
> }
>
> +/*
> + * csiphy_stream_on - Enable streaming on CSIPHY module
> + * @csiphy: CSIPHY device
> + *
> + * Helper function to enable streaming on CSIPHY module.
> + * Main configuration of CSIPHY module is also done here.
> + *
> + * Return 0 on success or a negative error code otherwise
> + */
> +static int csiphy_stream_on(struct csiphy_device *csiphy)
> +{
> + u8 bpp = csiphy_get_bpp(csiphy->res->formats->formats, csiphy->res->formats->nformats,
> + csiphy->fmt[MSM_CSIPHY_PAD_SINK].code);
> + u8 num_lanes = csiphy->cfg.csi2->lane_cfg.num_data;
> + struct phy_configure_opts_mipi_dphy *dphy_cfg;
> + union phy_configure_opts dphy_opts = { 0 };
> + struct device *dev = csiphy->camss->dev;
> + s64 link_freq;
> + int ret;
> +
> + dphy_cfg = &dphy_opts.mipi_dphy;
> +
> + link_freq = camss_get_link_freq(&csiphy->subdev.entity, bpp, num_lanes);
> +
> + if (link_freq < 0) {
> + dev_err(dev,
> + "Cannot get CSI2 transmitter's link frequency\n");
> + return -EINVAL;
> + }
> +
> + phy_mipi_dphy_get_default_config_for_hsclk(link_freq, num_lanes, dphy_cfg);
> +
> + phy_set_mode(csiphy->phy, PHY_MODE_MIPI_DPHY);
> + ret = phy_configure(csiphy->phy, &dphy_opts);
> + if (ret) {
> + dev_err(dev, "failed to configure MIPI D-PHY\n");
> + goto error;
> + }
> +
> + return phy_power_on(csiphy->phy);
> +
> +error:
> + return ret;
> +}
> +
> +/*
> + * csiphy_stream_off - Disable streaming on CSIPHY module
> + * @csiphy: CSIPHY device
> + *
> + * Helper function to disable streaming on CSIPHY module
> + */
> +static void csiphy_stream_off(struct csiphy_device *csiphy)
> +{
> + phy_power_off(csiphy->phy);
> +}
> +
> +/*
> + * csiphy_set_stream - Enable/disable streaming on CSIPHY module
> + * @sd: CSIPHY V4L2 subdevice
> + * @enable: Requested streaming state
> + *
> + * Return 0 on success or a negative error code otherwise
> + */
> +static int csiphy_set_stream_legacy(struct v4l2_subdev *sd, int enable)
> +{
> + struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
> + int ret = 0;
> +
> + if (enable)
> + ret = csiphy_stream_on_legacy(csiphy);
> + else
> + csiphy_stream_off_legacy(csiphy);
> +
> + return ret;
> +}
>
> /*
> * csiphy_set_stream - Enable/disable streaming on CSIPHY module
> @@ -568,16 +645,16 @@ static bool csiphy_match_clock_name(const char *clock_name, const char *format,
> }
>
> /*
> - * msm_csiphy_subdev_init - Initialize CSIPHY device structure and resources
> + * msm_csiphy_subdev_init_legacy - Initialize CSIPHY device structure and resources
> * @csiphy: CSIPHY device
> * @res: CSIPHY module resources table
> * @id: CSIPHY module id
> *
> * Return 0 on success or a negative error code otherwise
> */
> -int msm_csiphy_subdev_init(struct camss *camss,
> - struct csiphy_device *csiphy,
> - const struct camss_subdev_resources *res, u8 id)
> +int msm_csiphy_subdev_init_legacy(struct camss *camss,
> + struct csiphy_device *csiphy,
> + const struct camss_subdev_resources *res, u8 id)
> {
> struct device *dev = camss->dev;
> struct platform_device *pdev = to_platform_device(dev);
> @@ -705,6 +782,69 @@ int msm_csiphy_subdev_init(struct camss *camss,
> return ret;
> }
>
> +/*
> + * msm_csiphy_subdev_init - Initialize CSIPHY device structure and resources
> + * @csiphy: CSIPHY device
> + * @res: CSIPHY module resources table
> + * @id: CSIPHY module id
> + *
> + * Return 0 on success or a negative error code otherwise
> + */
> +int msm_csiphy_subdev_init(struct camss *camss,
> + struct csiphy_device *csiphy,
> + const struct camss_subdev_resources *res, u8 id)
> +{
> + struct device *dev = camss->dev;
> + struct of_phandle_args args;
> + u8 combo_mode;
> + int idx;
> + int ret;
> +
> + snprintf(csiphy->name, ARRAY_SIZE(csiphy->name), "csiphy%d", id);
> +
> + idx = of_property_match_string(dev->of_node, "phy-names", csiphy->name);
> + if (idx < 0) {
> + dev_err(dev, "%s not found\n", csiphy->name);
> + return idx;
> + }
> +
> + ret = of_parse_phandle_with_args(dev->of_node, "phys", "#phy-cells", idx, &args);
> + if (ret < 0) {
> + dev_err(dev, "unable to parse phys args %s\n", csiphy->name);
> + return ret;
> + }
> +
> + if (!of_device_is_available(args.np))
> + goto put_np;
> +
> + combo_mode = args.args[0];
> + if (combo_mode != PHY_TYPE_DPHY) {
> + dev_err(dev, "%s mode %d not supported\n", csiphy->name, combo_mode);
> + ret = -ENOTSUPP;
> + goto put_np;
> + }
> +
> + csiphy->phy = devm_phy_get(dev, csiphy->name);
> + if (IS_ERR(csiphy->phy)) {
> + ret = PTR_ERR(csiphy->phy);
> + goto put_np;
> + }
> +
> + csiphy->camss = camss;
> + csiphy->id = id;
> + csiphy->cfg.combo_mode = combo_mode;
> + csiphy->res = &res->csiphy;
> +
> + ret = phy_init(csiphy->phy);
> + if (ret)
> + dev_err(dev, "phy %s init fail %d\n", csiphy->name, ret);
> +
> +put_np:
> + of_node_put(args.np);
> +
> + return ret;
> +}
> +
> /*
> * csiphy_link_setup - Setup CSIPHY connections
> * @entity: Pointer to media entity structure
> @@ -739,8 +879,12 @@ static int csiphy_link_setup(struct media_entity *entity,
> return 0;
> }
>
> -static const struct v4l2_subdev_core_ops csiphy_core_ops = {
> - .s_power = csiphy_set_power,
> +static const struct v4l2_subdev_core_ops csiphy_core_ops_legacy = {
> + .s_power = csiphy_set_power_legacy,
> +};
> +
> +static const struct v4l2_subdev_video_ops csiphy_video_ops_legacy = {
> + .s_stream = csiphy_set_stream_legacy,
> };
>
> static const struct v4l2_subdev_video_ops csiphy_video_ops = {
> @@ -754,8 +898,13 @@ static const struct v4l2_subdev_pad_ops csiphy_pad_ops = {
> .set_fmt = csiphy_set_format,
> };
>
> +static const struct v4l2_subdev_ops csiphy_v4l2_ops_legacy = {
> + .core = &csiphy_core_ops_legacy,
> + .video = &csiphy_video_ops_legacy,
> + .pad = &csiphy_pad_ops,
> +};
> +
> static const struct v4l2_subdev_ops csiphy_v4l2_ops = {
> - .core = &csiphy_core_ops,
> .video = &csiphy_video_ops,
> .pad = &csiphy_pad_ops,
> };
> @@ -784,7 +933,11 @@ int msm_csiphy_register_entity(struct csiphy_device *csiphy,
> struct device *dev = csiphy->camss->dev;
> int ret;
>
> - v4l2_subdev_init(sd, &csiphy_v4l2_ops);
> + if (IS_ERR(csiphy->phy))
> + v4l2_subdev_init(sd, &csiphy_v4l2_ops_legacy);
> + else
> + v4l2_subdev_init(sd, &csiphy_v4l2_ops);
> +
> sd->internal_ops = &csiphy_v4l2_internal_ops;
> sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> snprintf(sd->name, ARRAY_SIZE(sd->name), "%s%d",
> @@ -823,6 +976,8 @@ int msm_csiphy_register_entity(struct csiphy_device *csiphy,
> */
> void msm_csiphy_unregister_entity(struct csiphy_device *csiphy)
> {
> + if (!IS_ERR(csiphy->phy))
> + phy_exit(csiphy->phy);
> v4l2_device_unregister_subdev(&csiphy->subdev);
> media_entity_cleanup(&csiphy->subdev.entity);
> }
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h
> index 2d5054819df7f..25b803c06e8bf 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.h
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
> @@ -12,6 +12,7 @@
>
> #include <linux/clk.h>
> #include <linux/interrupt.h>
> +#include <linux/phy/phy.h>
> #include <media/media-entity.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-mediabus.h>
> @@ -95,6 +96,7 @@ struct csiphy_device_regs {
>
> struct csiphy_device {
> struct camss *camss;
> + struct phy *phy;
> u8 id;
> struct v4l2_subdev subdev;
> struct media_pad pads[MSM_CSIPHY_PADS_NUM];
> @@ -102,6 +104,7 @@ struct csiphy_device {
> void __iomem *base_clk_mux;
> u32 irq;
> char irq_name[30];
> + char name[16];
> struct camss_clock *clock;
> bool *rate_set;
> int nclocks;
> @@ -116,6 +119,10 @@ struct csiphy_device {
>
> struct camss_subdev_resources;
>
> +int msm_csiphy_subdev_init_legacy(struct camss *camss,
> + struct csiphy_device *csiphy,
> + const struct camss_subdev_resources *res, u8 id);
> +
> int msm_csiphy_subdev_init(struct camss *camss,
> struct csiphy_device *csiphy,
> const struct camss_subdev_resources *res, u8 id);
> diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
> index 5fb5ad87e1671..b1737b5d52160 100644
> --- a/drivers/media/platform/qcom/camss/camss.c
> +++ b/drivers/media/platform/qcom/camss/camss.c
> @@ -4450,14 +4450,35 @@ static int camss_parse_endpoint_node(struct device *dev,
> static int camss_parse_ports(struct camss *camss)
> {
> struct device *dev = camss->dev;
> + const struct camss_resources *res = camss->res;
> struct fwnode_handle *fwnode = dev_fwnode(dev), *ep;
> int ret;
>
> fwnode_graph_for_each_endpoint(fwnode, ep) {
> struct camss_async_subdev *csd;
> + struct fwnode_handle *remote;
> +
> + if (!fwnode_device_is_available(ep))
> + continue;
> +
> + if (res->legacy_phy) {
> + csd = v4l2_async_nf_add_fwnode_remote(&camss->notifier, ep,
> + typeof(*csd));
> + } else {
> + /*
> + * For non-legacy PHY, the CSIPHY is a separate device.
> + * Register the remote endpoint (CSIPHY's endpoint) as
> + * the async subdev, not the remote port parent.
> + */
> + remote = fwnode_graph_get_remote_endpoint(ep);
> + if (!remote)
> + continue;
> +
> + csd = v4l2_async_nf_add_fwnode(&camss->notifier, remote,
> + struct camss_async_subdev);
> + fwnode_handle_put(remote);
> + }
>
> - csd = v4l2_async_nf_add_fwnode_remote(&camss->notifier, ep,
> - typeof(*csd));
> if (IS_ERR(csd)) {
> ret = PTR_ERR(csd);
> goto err_cleanup;
> @@ -4489,15 +4510,26 @@ static int camss_init_subdevices(struct camss *camss)
> unsigned int i;
> int ret;
>
> - for (i = 0; i < camss->res->csiphy_num; i++) {
> - ret = msm_csiphy_subdev_init(camss, &camss->csiphy[i],
> - &res->csiphy_res[i],
> - res->csiphy_res[i].csiphy.id);
> - if (ret < 0) {
> - dev_err(camss->dev,
> - "Failed to init csiphy%d sub-device: %d\n",
> - i, ret);
> - return ret;
> + if (!res->legacy_phy) {
> + for (i = 0; i < camss->res->csiphy_num; i++) {
> + ret = msm_csiphy_subdev_init(camss, &camss->csiphy[i],
> + &res->csiphy_res[i],
> + res->csiphy_res[i].csiphy.id);
> + if (ret < 0)
> + return ret;
> + }
> + } else {
> + for (i = 0; i < camss->res->csiphy_num; i++) {
> + ret = msm_csiphy_subdev_init_legacy(camss, &camss->csiphy[i],
> + &res->csiphy_res[i],
> + res->csiphy_res[i].csiphy.id);
> + if (ret < 0) {
> + dev_err(camss->dev,
> + "Failed to init csiphy%d sub-device: %d\n",
> + i, ret);
> + return ret;
> + }
> + camss->csiphy[i].phy = ERR_PTR(-ENODEV);
> }
> }
>
> @@ -4574,6 +4606,9 @@ static int camss_link_entities(struct camss *camss)
>
> for (i = 0; i < camss->res->csiphy_num; i++) {
> for (j = 0; j < camss->res->csid_num; j++) {
> + if (!camss->csiphy[i].phy)
> + continue;
> +
> ret = media_create_pad_link(&camss->csiphy[i].subdev.entity,
> MSM_CSIPHY_PAD_SRC,
> &camss->csid[j].subdev.entity,
> @@ -4683,6 +4718,9 @@ static int camss_register_entities(struct camss *camss)
> int ret;
>
> for (i = 0; i < camss->res->csiphy_num; i++) {
> + if (!camss->csiphy[i].phy)
> + continue;
> +
> ret = msm_csiphy_register_entity(&camss->csiphy[i],
> &camss->v4l2_dev);
> if (ret < 0) {
> @@ -4738,8 +4776,10 @@ static int camss_register_entities(struct camss *camss)
>
> i = camss->res->csiphy_num;
> err_reg_csiphy:
> - for (i--; i >= 0; i--)
> - msm_csiphy_unregister_entity(&camss->csiphy[i]);
> + for (i--; i >= 0; i--) {
> + if (camss->csiphy[i].phy)
> + msm_csiphy_unregister_entity(&camss->csiphy[i]);
> + }
>
> return ret;
> }
> @@ -4754,8 +4794,10 @@ static void camss_unregister_entities(struct camss *camss)
> {
> unsigned int i;
>
> - for (i = 0; i < camss->res->csiphy_num; i++)
> - msm_csiphy_unregister_entity(&camss->csiphy[i]);
> + for (i = 0; i < camss->res->csiphy_num; i++) {
> + if (camss->csiphy[i].phy)
> + msm_csiphy_unregister_entity(&camss->csiphy[i]);
> + }
>
> for (i = 0; i < camss->res->csid_num; i++)
> msm_csid_unregister_entity(&camss->csid[i]);