Re: [PATCH v5 3/4] media: platform: Add Renesas RZ/G2L MIPI CSI-2 receiver driver

From: Laurent Pinchart
Date: Mon Nov 21 2022 - 20:15:37 EST


Hi Prabhakar,

Thank you for the patch.

On Wed, Nov 02, 2022 at 12:43:28AM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Add MIPI CSI-2 receiver driver for Renesas RZ/G2L. The MIPI
> CSI-2 is part of the CRU module found on RZ/G2L family.
>
> Based on a patch in the BSP by Hien Huynh
> <hien.huynh.px@xxxxxxxxxxx>
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> v4 -> v5
> * Made sure to cleanup in s_stream error path
>
> v3 -> v4
> * Implemented post_streamoff callback
>
> v2 -> v3
> * Switched to runtime PM
> * Implemented pre_streamon callback in CSI driver
> * Got rid of rzg2l_csi2_cmn_rstb_deassert()/
> rzg2l_csi2_dphy_setting/rzg2l_csi2_mipi_link_setting() from CSI driver
> * Switched to for-loop instead of if block for getting CSI timings
> * Fixed rzg2l_csi2_set_format() as pointed by Laurent
> * Copied all colorspace-related fields received from userspace (colorspace,
> xfer_func, ycbcr_enc and quantization) in rzg2l_csi2_set_format.
> * Initialised pad in rzg2l_csi2_init_config()
> * Introduced RZG2L_CSI2_DEFAULT_WIDTH/HEIGHT/FMT macros
> * Dropped RZG2L_CSI2_SOURCE_VC0-RZG2L_CSI2_SOURCE_VC3 macros
>
> v1 -> v2
> * Sorted Kconfig select
> * Prefixed generic names for struct/variables with rzg2_csi2
> * Dropped unnecessary checks for remote source
> * Dropped exporting functions
> * Moved lane validation to probe
> * Split up rzg2l_csi2_dphy_setting() and rzg2l_csi2_mipi_link_setting()
> * Used rzg2l_csi2_write() wherever possible
> * Dropped stream_count/lock
> * Used active subdev state instead of manually storing format in driver
> * Implemented init_cfg/enum_frame_size/enum_mbus_code callbacks
> * Dropped check for bus_type of remote source
> * Switched to manually turn ON/OFF the clocks instead of pm_runtime so that
> the mipi/dhpy initialization happens as per the HW manual
> * Hardcoded VC0 usage for now as streams API is under development
>
> RFC v2 -> v1
> * Fixed initialization sequence of DPHY and link
> * Exported DPHY and link initialization functions so that the
> CRU core driver can initialize the CRU and CSI2 as per the HW manual.
>
> RFC v1 -> RFC v2
> * new patch (split up as new driver compared to v1)
> ---
> drivers/media/platform/renesas/Kconfig | 1 +
> drivers/media/platform/renesas/Makefile | 1 +
> .../media/platform/renesas/rzg2l-cru/Kconfig | 17 +
> .../media/platform/renesas/rzg2l-cru/Makefile | 3 +
> .../platform/renesas/rzg2l-cru/rzg2l-csi2.c | 885 ++++++++++++++++++
> 5 files changed, 907 insertions(+)
> create mode 100644 drivers/media/platform/renesas/rzg2l-cru/Kconfig
> create mode 100644 drivers/media/platform/renesas/rzg2l-cru/Makefile
> create mode 100644 drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
>
> diff --git a/drivers/media/platform/renesas/Kconfig b/drivers/media/platform/renesas/Kconfig
> index 9fd90672ea2d..ed788e991f74 100644
> --- a/drivers/media/platform/renesas/Kconfig
> +++ b/drivers/media/platform/renesas/Kconfig
> @@ -41,6 +41,7 @@ config VIDEO_SH_VOU
> Support for the Video Output Unit (VOU) on SuperH SoCs.
>
> source "drivers/media/platform/renesas/rcar-vin/Kconfig"
> +source "drivers/media/platform/renesas/rzg2l-cru/Kconfig"
>
> # Mem2mem drivers
>
> diff --git a/drivers/media/platform/renesas/Makefile b/drivers/media/platform/renesas/Makefile
> index 3ec226ef5fd2..55854e868887 100644
> --- a/drivers/media/platform/renesas/Makefile
> +++ b/drivers/media/platform/renesas/Makefile
> @@ -4,6 +4,7 @@
> #
>
> obj-y += rcar-vin/
> +obj-y += rzg2l-cru/
> obj-y += vsp1/
>
> obj-$(CONFIG_VIDEO_RCAR_DRIF) += rcar_drif.o
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/Kconfig b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> new file mode 100644
> index 000000000000..57c40bb499df
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/Kconfig
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +config VIDEO_RZG2L_CSI2
> + tristate "RZ/G2L MIPI CSI-2 Receiver"
> + depends on ARCH_RENESAS || COMPILE_TEST
> + depends on V4L_PLATFORM_DRIVERS
> + depends on VIDEO_DEV && OF
> + select MEDIA_CONTROLLER
> + select RESET_CONTROLLER
> + select V4L2_FWNODE
> + select VIDEO_V4L2_SUBDEV_API
> + help
> + Support for Renesas RZ/G2L (and alike SoC's) MIPI CSI-2
> + Receiver driver.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called rzg2l-csi2.
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/Makefile b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> new file mode 100644
> index 000000000000..91ea97a944e6
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_VIDEO_RZG2L_CSI2) += rzg2l-csi2.o
> diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
> new file mode 100644
> index 000000000000..2ab9e8454a04
> --- /dev/null
> +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
> @@ -0,0 +1,885 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for Renesas RZ/G2L MIPI CSI-2 Receiver
> + *
> + * Copyright (C) 2022 Renesas Electronics Corp.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/sys_soc.h>
> +#include <linux/units.h>
> +
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mc.h>
> +#include <media/v4l2-subdev.h>
> +
> +/* LINK registers */
> +/* Module Configuration Register */
> +#define CSI2nMCG 0x0
> +#define CSI2nMCG_SDLN GENMASK(11, 8)
> +
> +/* Module Control Register 0 */
> +#define CSI2nMCT0 0x10
> +#define CSI2nMCT0_VDLN(x) ((x) << 0)
> +
> +/* Module Control Register 2 */
> +#define CSI2nMCT2 0x18
> +#define CSI2nMCT2_FRRSKW(x) ((x) << 16)
> +#define CSI2nMCT2_FRRCLK(x) ((x) << 0)
> +
> +/* Module Control Register 3 */
> +#define CSI2nMCT3 0x1c
> +#define CSI2nMCT3_RXEN BIT(0)
> +
> +/* Reset Control Register */
> +#define CSI2nRTCT 0x28
> +#define CSI2nRTCT_VSRST BIT(0)
> +
> +/* Reset Status Register */
> +#define CSI2nRTST 0x2c
> +#define CSI2nRTST_VSRSTS BIT(0)
> +
> +/* Receive Data Type Enable Low Register */
> +#define CSI2nDTEL 0x60
> +
> +/* Receive Data Type Enable High Register */
> +#define CSI2nDTEH 0x64
> +
> +/* DPHY registers */
> +/* D-PHY Control Register 0 */
> +#define CSIDPHYCTRL0 0x400
> +#define CSIDPHYCTRL0_EN_LDO1200 BIT(1)
> +#define CSIDPHYCTRL0_EN_BGR BIT(0)
> +
> +/* D-PHY Timing Register 0 */
> +#define CSIDPHYTIM0 0x404
> +#define CSIDPHYTIM0_TCLK_MISS(x) ((x) << 24)
> +#define CSIDPHYTIM0_T_INIT(x) ((x) << 0)
> +
> +/* D-PHY Timing Register 1 */
> +#define CSIDPHYTIM1 0x408
> +#define CSIDPHYTIM1_THS_PREPARE(x) ((x) << 24)
> +#define CSIDPHYTIM1_TCLK_PREPARE(x) ((x) << 16)
> +#define CSIDPHYTIM1_THS_SETTLE(x) ((x) << 8)
> +#define CSIDPHYTIM1_TCLK_SETTLE(x) ((x) << 0)
> +
> +/* D-PHY Skew Adjustment Function */
> +#define CSIDPHYSKW0 0x460
> +#define CSIDPHYSKW0_UTIL_DL0_SKW_ADJ(x) ((x) & 0x3)
> +#define CSIDPHYSKW0_UTIL_DL1_SKW_ADJ(x) (((x) & 0x3) << 4)
> +#define CSIDPHYSKW0_UTIL_DL2_SKW_ADJ(x) (((x) & 0x3) << 8)
> +#define CSIDPHYSKW0_UTIL_DL3_SKW_ADJ(x) (((x) & 0x3) << 12)
> +#define CSIDPHYSKW0_DEFAULT_SKW CSIDPHYSKW0_UTIL_DL0_SKW_ADJ(1) | \
> + CSIDPHYSKW0_UTIL_DL1_SKW_ADJ(1) | \
> + CSIDPHYSKW0_UTIL_DL2_SKW_ADJ(1) | \
> + CSIDPHYSKW0_UTIL_DL3_SKW_ADJ(1)
> +
> +#define VSRSTS_RETRIES 20
> +
> +#define RZG2L_CSI2_MIN_WIDTH 320
> +#define RZG2L_CSI2_MIN_HEIGHT 240
> +#define RZG2L_CSI2_MAX_WIDTH 2800
> +#define RZG2L_CSI2_MAX_HEIGHT 4095
> +
> +#define RZG2L_CSI2_DEFAULT_WIDTH RZG2L_CSI2_MIN_WIDTH
> +#define RZG2L_CSI2_DEFAULT_HEIGHT RZG2L_CSI2_MIN_HEIGHT
> +#define RZG2L_CSI2_DEFAULT_FMT MEDIA_BUS_FMT_UYVY8_1X16
> +
> +enum rzg2l_csi2_pads {
> + RZG2L_CSI2_SINK = 0,
> + RZG2L_CSI2_SOURCE,
> + NR_OF_RZG2L_CSI2_PAD,
> +};
> +
> +struct rzg2l_csi2 {
> + struct device *dev;
> + void __iomem *base;
> + struct reset_control *presetn;
> + struct reset_control *cmn_rstb;
> + struct clk *sysclk;
> + unsigned long vclk_rate;
> +
> + struct v4l2_subdev subdev;
> + struct media_pad pads[NR_OF_RZG2L_CSI2_PAD];
> +
> + struct v4l2_async_notifier notifier;
> + struct v4l2_subdev *remote_source;
> +
> + unsigned short lanes;
> + unsigned long hsfreq;
> +
> + bool dphy_enabled;
> +};
> +
> +struct rzg2l_csi2_timings {
> + u32 t_init;
> + u32 tclk_miss;
> + u32 tclk_settle;
> + u32 ths_settle;
> + u32 tclk_prepare;
> + u32 ths_prepare;
> + u32 max_hsfreq;
> +};
> +
> +static const struct rzg2l_csi2_timings rzg2l_csi2_global_timings[] = {
> + [0] = {

You can drop [0]. Same below.

> + .max_hsfreq = 80,
> + .t_init = 79801,
> + .tclk_miss = 4,
> + .tclk_settle = 23,
> + .ths_settle = 31,
> + .tclk_prepare = 10,
> + .ths_prepare = 19,
> + },
> + [1] = {
> + .max_hsfreq = 125,
> + .t_init = 79801,
> + .tclk_miss = 4,
> + .tclk_settle = 23,
> + .ths_settle = 28,
> + .tclk_prepare = 10,
> + .ths_prepare = 19,
> + },
> + [2] = {
> + .max_hsfreq = 250,
> + .t_init = 79801,
> + .tclk_miss = 4,
> + .tclk_settle = 23,
> + .ths_settle = 22,
> + .tclk_prepare = 10,
> + .ths_prepare = 16,
> + },
> + [3] = {
> + .max_hsfreq = 360,
> + .t_init = 79801,
> + .tclk_miss = 4,
> + .tclk_settle = 18,
> + .ths_settle = 19,
> + .tclk_prepare = 10,
> + .ths_prepare = 10,
> + },
> + [4] = {
> + .max_hsfreq = 1500,
> + .t_init = 79801,
> + .tclk_miss = 4,
> + .tclk_settle = 18,
> + .ths_settle = 18,
> + .tclk_prepare = 10,
> + .ths_prepare = 10,
> + },
> +};
> +
> +struct rzg2l_csi2_format {
> + u32 code;
> + unsigned int datatype;
> + unsigned int bpp;
> +};
> +
> +static const struct rzg2l_csi2_format rzg2l_csi2_formats[] = {
> + { .code = MEDIA_BUS_FMT_UYVY8_1X16, .datatype = 0x1e, .bpp = 16 },
> +};
> +
> +static inline struct rzg2l_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
> +{
> + return container_of(sd, struct rzg2l_csi2, subdev);
> +}
> +
> +static const struct rzg2l_csi2_format *rzg2l_csi2_code_to_fmt(unsigned int code)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_formats); i++)
> + if (rzg2l_csi2_formats[i].code == code)
> + return &rzg2l_csi2_formats[i];
> +
> + return NULL;
> +}
> +
> +static inline struct rzg2l_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
> +{
> + return container_of(n, struct rzg2l_csi2, notifier);
> +}
> +
> +static u32 rzg2l_csi2_read(struct rzg2l_csi2 *csi2, unsigned int reg)
> +{
> + return ioread32(csi2->base + reg);
> +}
> +
> +static void rzg2l_csi2_write(struct rzg2l_csi2 *csi2, unsigned int reg,
> + u32 data)
> +{
> + iowrite32(data, csi2->base + reg);
> +}
> +
> +static void rzg2l_csi2_set(struct rzg2l_csi2 *csi2, unsigned int reg, u32 set)
> +{
> + rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) | set);
> +}
> +
> +static void rzg2l_csi2_clr(struct rzg2l_csi2 *csi2, unsigned int reg, u32 clr)
> +{
> + rzg2l_csi2_write(csi2, reg, rzg2l_csi2_read(csi2, reg) & ~clr);
> +}
> +
> +static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
> +{
> + struct v4l2_subdev *source = csi2->remote_source;
> + const struct rzg2l_csi2_format *format;
> + const struct v4l2_mbus_framefmt *fmt;
> + struct v4l2_subdev_state *state;
> + struct v4l2_ctrl *ctrl;
> + u64 mbps;
> +
> + /* Read the pixel rate control from remote. */
> + ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
> + if (!ctrl) {
> + dev_err(csi2->dev, "no pixel rate control in subdev %s\n",
> + source->name);
> + return -EINVAL;
> + }
> +
> + state = v4l2_subdev_lock_and_get_active_state(&csi2->subdev);
> + fmt = v4l2_subdev_get_pad_format(&csi2->subdev, state, RZG2L_CSI2_SINK);
> + format = rzg2l_csi2_code_to_fmt(fmt->code);
> + v4l2_subdev_unlock_state(state);
> +
> + /*
> + * Calculate hsfreq in Mbps
> + * hsfreq = (pixel_rate * bits_per_sample) / number_of_lanes
> + */
> + mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * format->bpp;
> + do_div(mbps, csi2->lanes * 1000000);
> +
> + return mbps;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * DPHY setting
> + */
> +
> +static int rzg2l_csi2_dphy_disable(struct rzg2l_csi2 *csi2)
> +{
> + int ret;
> +
> + /* Reset the CRU (D-PHY) */
> + ret = reset_control_assert(csi2->cmn_rstb);
> + if (ret)
> + return ret;
> +
> + /* Stop the D-PHY clock */
> + clk_disable_unprepare(csi2->sysclk);
> +
> + /* Cancel the EN_LDO1200 register setting */
> + rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> +
> + /* Cancel the EN_BGR register setting */
> + rzg2l_csi2_clr(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> +
> + csi2->dphy_enabled = false;
> +
> + return 0;
> +}
> +
> +static int rzg2l_csi2_dphy_enable(struct rzg2l_csi2 *csi2)
> +{
> + const struct rzg2l_csi2_timings *dphy_timing;
> + u32 dphytim0, dphytim1;
> + unsigned int i;
> + int mbps;
> + int ret;
> +
> + mbps = rzg2l_csi2_calc_mbps(csi2);
> + if (mbps < 0)
> + return mbps;
> +
> + csi2->hsfreq = mbps;
> +
> + /* Set DPHY timing parameters */
> + for (i = 0; i < ARRAY_SIZE(rzg2l_csi2_global_timings); ++i) {
> + dphy_timing = &rzg2l_csi2_global_timings[i];
> +
> + if (csi2->hsfreq <= dphy_timing->max_hsfreq)
> + break;
> + }
> +
> + if (i >= ARRAY_SIZE(rzg2l_csi2_global_timings))
> + return -EINVAL;
> +
> + /* Set D-PHY timing parameters */
> + dphytim0 = CSIDPHYTIM0_TCLK_MISS(dphy_timing->tclk_miss) |
> + CSIDPHYTIM0_T_INIT(dphy_timing->t_init);
> + dphytim1 = CSIDPHYTIM1_THS_PREPARE(dphy_timing->ths_prepare) |
> + CSIDPHYTIM1_TCLK_PREPARE(dphy_timing->tclk_prepare) |
> + CSIDPHYTIM1_THS_SETTLE(dphy_timing->ths_settle) |
> + CSIDPHYTIM1_TCLK_SETTLE(dphy_timing->tclk_settle);
> + rzg2l_csi2_write(csi2, CSIDPHYTIM0, dphytim0);
> + rzg2l_csi2_write(csi2, CSIDPHYTIM1, dphytim1);
> +
> + /* Enable D-PHY power control 0 */
> + rzg2l_csi2_write(csi2, CSIDPHYSKW0, CSIDPHYSKW0_DEFAULT_SKW);
> +
> + /* Set the EN_BGR bit */
> + rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_BGR);
> +
> + /* Delay 20us to be stable */
> + usleep_range(20, 40);
> +
> + /* Enable D-PHY power control 1 */
> + rzg2l_csi2_set(csi2, CSIDPHYCTRL0, CSIDPHYCTRL0_EN_LDO1200);
> +
> + /* Delay 10us to be stable */
> + usleep_range(10, 20);
> +
> + /* Start supplying the internal clock for the D-PHY block */
> + ret = clk_prepare_enable(csi2->sysclk);
> + if (ret)
> + rzg2l_csi2_dphy_disable(csi2);
> +
> + csi2->dphy_enabled = true;
> +
> + return ret;
> +}
> +
> +static int rzg2l_csi2_enable_reg_access(struct rzg2l_csi2 *csi2)
> +{
> + int ret;
> +
> + ret = reset_control_deassert(csi2->presetn);
> + if (ret < 0)
> + return ret;

Could this be done in the runtime PM resume handler ? Same for
reset_control_assert() in the runtime PM suspend handler.

> +
> + ret = pm_runtime_resume_and_get(csi2->dev);
> + if (ret)
> + reset_control_assert(csi2->presetn);
> +
> + return ret;
> +}
> +
> +static void rzg2l_csi2_disable_reg_access(struct rzg2l_csi2 *csi2)
> +{
> + pm_runtime_put_sync(csi2->dev);
> + reset_control_assert(csi2->presetn);
> +}
> +
> +static int rzg2l_csi2_dphy_setting(struct v4l2_subdev *sd, bool on)
> +{
> + struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> + int ret;
> +
> + ret = rzg2l_csi2_enable_reg_access(csi2);
> + if (ret < 0)
> + return ret;
> +
> + if (on)
> + ret = rzg2l_csi2_dphy_enable(csi2);
> + else
> + ret = rzg2l_csi2_dphy_disable(csi2);
> +
> + rzg2l_csi2_disable_reg_access(csi2);
> +
> + return ret;
> +}
> +
> +static void rzg2l_csi2_mipi_link_enable(struct rzg2l_csi2 *csi2)
> +{
> + unsigned long vclk_rate = csi2->vclk_rate / HZ_PER_MHZ;
> + u32 frrskw, frrclk, frrskw_coeff, frrclk_coeff;
> +
> + /* Select data lanes */
> + rzg2l_csi2_write(csi2, CSI2nMCT0, CSI2nMCT0_VDLN(csi2->lanes));
> +
> + frrskw_coeff = 3 * vclk_rate * 8;
> + frrclk_coeff = frrskw_coeff / 2;
> + frrskw = DIV_ROUND_UP(frrskw_coeff, csi2->hsfreq);
> + frrclk = DIV_ROUND_UP(frrclk_coeff, csi2->hsfreq);
> + rzg2l_csi2_write(csi2, CSI2nMCT2, CSI2nMCT2_FRRSKW(frrskw) |
> + CSI2nMCT2_FRRCLK(frrclk));
> +
> + /*
> + * Select data type.
> + * FS, FE, LS, LE, Generic Short Packet Codes 1 to 8,
> + * Generic Long Packet Data Types 1 to 4 YUV422 8-bit,
> + * RGB565, RGB888, RAW8 to RAW20, User-defined 8-bit
> + * data types 1 to 8
> + */
> + rzg2l_csi2_write(csi2, CSI2nDTEL, 0xf778ff0f);
> + rzg2l_csi2_write(csi2, CSI2nDTEH, 0x00ffff1f);
> +
> + /* Enable LINK reception */
> + rzg2l_csi2_write(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> +}
> +
> +static void rzg2l_csi2_mipi_link_disable(struct rzg2l_csi2 *csi2)
> +{
> + unsigned int timeout = VSRSTS_RETRIES;
> +
> + /* Stop LINK reception */
> + rzg2l_csi2_clr(csi2, CSI2nMCT3, CSI2nMCT3_RXEN);
> +
> + /* Request a software reset of the LINK Video Pixel Interface */
> + rzg2l_csi2_write(csi2, CSI2nRTCT, CSI2nRTCT_VSRST);
> +
> + /* Make sure CSI2nRTST.VSRSTS bit is cleared */
> + while (timeout--) {
> + if (!(rzg2l_csi2_read(csi2, CSI2nRTST) & CSI2nRTST_VSRSTS))
> + break;
> + usleep_range(100, 200);
> + };
> +
> + if (!timeout)
> + dev_err(csi2->dev, "Clearing CSI2nRTST.VSRSTS timed out\n");
> +}
> +
> +static int rzg2l_csi2_mipi_link_setting(struct v4l2_subdev *sd, bool on)
> +{
> + struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> + int ret;
> +
> + ret = rzg2l_csi2_enable_reg_access(csi2);
> + if (ret < 0)
> + return ret;
> +
> + if (on)
> + rzg2l_csi2_mipi_link_enable(csi2);
> + else
> + rzg2l_csi2_mipi_link_disable(csi2);
> +
> + rzg2l_csi2_disable_reg_access(csi2);

This doesn't seem right. Runtime PM isn't just about register access.
You need to call pm_runtime_resume_and_get() at the beginning of
rzg2l_csi2_s_stream() when enabling, and pm_runtime_put_sync() at the
end of rzg2l_csi2_s_stream() when disabling (+ error paths for the
enable case).

> +
> + return 0;
> +}
> +
> +static int rzg2l_csi2_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> + struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> + int s_stream_ret = 0;
> + int ret;
> +
> + if (enable) {
> + int ret;
> +
> + ret = rzg2l_csi2_mipi_link_setting(sd, 1);
> + if (ret)
> + return ret;
> +
> + ret = reset_control_deassert(csi2->cmn_rstb);
> + if (ret)
> + goto err_mipi_link_disable;
> + }
> +
> + ret = v4l2_subdev_call(csi2->remote_source, video, s_stream, enable);
> + if (ret) {
> + s_stream_ret = ret;
> + dev_err(csi2->dev, "s_stream failed on remote source\n");

With
https://lore.kernel.org/linux-media/20221026065123.595777-1-sakari.ailus@xxxxxxxxxxxxxxx/
I think you can drop this error message.

> + }
> +
> + if (enable && ret)
> + goto err_assert_rstb;
> +
> + if (!enable) {
> + ret = rzg2l_csi2_dphy_setting(sd, 0);
> + if (ret && !s_stream_ret)
> + s_stream_ret = ret;
> + ret = rzg2l_csi2_mipi_link_setting(sd, 0);
> + if (ret && !s_stream_ret)
> + s_stream_ret = ret;
> + }
> +
> + return s_stream_ret;
> +
> +err_assert_rstb:
> + reset_control_assert(csi2->cmn_rstb);
> +err_mipi_link_disable:
> + rzg2l_csi2_mipi_link_setting(sd, 0);
> + return ret;
> +}
> +
> +static int rzg2l_csi2_pre_streamon(struct v4l2_subdev *sd, u32 flags)
> +{
> + return rzg2l_csi2_dphy_setting(sd, 1);
> +}
> +
> +static int rzg2l_csi2_post_streamoff(struct v4l2_subdev *sd)
> +{
> + struct rzg2l_csi2 *csi2 = sd_to_csi2(sd);
> +
> + /*
> + * In ideal case D-PHY will be disabled in s_stream(0) callback
> + * as mentioned the HW manual. The below will only happen when
> + * pre_streamon succeeds and further down the line s_stream(1)
> + * fails so we need to undo things in post_streamoff.
> + */
> + if (csi2->dphy_enabled)
> + return rzg2l_csi2_dphy_setting(sd, 0);
> +
> + return 0;
> +}
> +
> +static int rzg2l_csi2_set_format(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state,
> + struct v4l2_subdev_format *fmt)
> +{
> + struct v4l2_mbus_framefmt *src_format;
> + struct v4l2_mbus_framefmt *sink_format;
> +
> + if (fmt->pad != RZG2L_CSI2_SINK && fmt->pad != RZG2L_CSI2_SOURCE)
> + return -EINVAL;

You can drop this check as the set_format wrapper validates the pad
value already.

> +
> + sink_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SINK);
> + src_format = v4l2_subdev_get_pad_format(sd, state, RZG2L_CSI2_SOURCE);

As the CSI-2 receiver can't modify the format on the output,
set_format() on the source pad must not modify the format. Just add

if (fmt->pad == RZG2L_CSI2_SOURCE) {
fmt->format = *src_format;
return 0;
}

here.

> +
> + if (!rzg2l_csi2_code_to_fmt(fmt->format.code))
> + sink_format->code = rzg2l_csi2_formats[0].code;
> + else
> + sink_format->code = fmt->format.code;
> +
> + sink_format->field = V4L2_FIELD_NONE;
> + sink_format->colorspace = fmt->format.colorspace;
> + sink_format->xfer_func = fmt->format.xfer_func;
> + sink_format->ycbcr_enc = fmt->format.ycbcr_enc;
> + sink_format->quantization = fmt->format.quantization;
> + sink_format->width = clamp_t(u32, fmt->format.width,
> + RZG2L_CSI2_MIN_WIDTH, RZG2L_CSI2_MAX_WIDTH);
> + sink_format->height = clamp_t(u32, fmt->format.height,
> + RZG2L_CSI2_MIN_HEIGHT, RZG2L_CSI2_MAX_HEIGHT);
> + fmt->format = *sink_format;
> +
> + /* propagate format to source pad */
> + *src_format = *sink_format;
> +
> + return 0;
> +}
> +
> +static int rzg2l_csi2_init_config(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state)
> +{
> + struct v4l2_subdev_format fmt = { .pad = RZG2L_CSI2_SINK, };
> +
> + fmt.format.width = RZG2L_CSI2_DEFAULT_WIDTH;
> + fmt.format.height = RZG2L_CSI2_DEFAULT_HEIGHT;
> + fmt.format.field = V4L2_FIELD_NONE;
> + fmt.format.code = RZG2L_CSI2_DEFAULT_FMT;
> + fmt.format.colorspace = V4L2_COLORSPACE_SRGB;
> + fmt.format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> + fmt.format.quantization = V4L2_QUANTIZATION_DEFAULT;
> + fmt.format.xfer_func = V4L2_XFER_FUNC_DEFAULT;
> +
> + return rzg2l_csi2_set_format(sd, sd_state, &fmt);
> +}
> +
> +static int rzg2l_csi2_enum_mbus_code(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_mbus_code_enum *code)
> +{
> + if (code->index >= ARRAY_SIZE(rzg2l_csi2_formats))
> + return -EINVAL;
> +
> + code->code = rzg2l_csi2_formats[code->index].code;
> +
> + return 0;
> +}
> +
> +static int rzg2l_csi2_enum_frame_size(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *sd_state,
> + struct v4l2_subdev_frame_size_enum *fse)
> +{
> + if (fse->index != 0)
> + return -EINVAL;
> +
> + fse->min_width = RZG2L_CSI2_MIN_WIDTH;
> + fse->min_height = RZG2L_CSI2_MIN_HEIGHT;
> + fse->max_width = RZG2L_CSI2_MAX_WIDTH;
> + fse->max_height = RZG2L_CSI2_MAX_HEIGHT;
> +
> + return 0;
> +}
> +
> +static const struct v4l2_subdev_video_ops rzg2l_csi2_video_ops = {
> + .s_stream = rzg2l_csi2_s_stream,
> + .pre_streamon = rzg2l_csi2_pre_streamon,
> + .post_streamoff = rzg2l_csi2_post_streamoff,
> +};
> +
> +static const struct v4l2_subdev_pad_ops rzg2l_csi2_pad_ops = {
> + .enum_mbus_code = rzg2l_csi2_enum_mbus_code,
> + .init_cfg = rzg2l_csi2_init_config,
> + .enum_frame_size = rzg2l_csi2_enum_frame_size,
> + .set_fmt = rzg2l_csi2_set_format,
> + .get_fmt = v4l2_subdev_get_fmt,
> +};
> +
> +static const struct v4l2_subdev_ops rzg2l_csi2_subdev_ops = {
> + .video = &rzg2l_csi2_video_ops,
> + .pad = &rzg2l_csi2_pad_ops,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Async handling and registration of subdevices and links.
> + */
> +
> +static int rzg2l_csi2_notify_bound(struct v4l2_async_notifier *notifier,
> + struct v4l2_subdev *subdev,
> + struct v4l2_async_subdev *asd)
> +{
> + struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> +
> + csi2->remote_source = subdev;
> +
> + dev_dbg(csi2->dev, "Bound subdev: %s pad\n", subdev->name);
> +
> + return media_create_pad_link(&subdev->entity, RZG2L_CSI2_SINK,
> + &csi2->subdev.entity, 0,
> + MEDIA_LNK_FL_ENABLED |
> + MEDIA_LNK_FL_IMMUTABLE);
> +}
> +
> +static void rzg2l_csi2_notify_unbind(struct v4l2_async_notifier *notifier,
> + struct v4l2_subdev *subdev,
> + struct v4l2_async_subdev *asd)
> +{
> + struct rzg2l_csi2 *csi2 = notifier_to_csi2(notifier);
> +
> + csi2->remote_source = NULL;
> +
> + dev_dbg(csi2->dev, "Unbind subdev %s\n", subdev->name);
> +}
> +
> +static const struct v4l2_async_notifier_operations rzg2l_csi2_notify_ops = {
> + .bound = rzg2l_csi2_notify_bound,
> + .unbind = rzg2l_csi2_notify_unbind,
> +};
> +
> +static int rzg2l_csi2_parse_v4l2(struct rzg2l_csi2 *csi2,
> + struct v4l2_fwnode_endpoint *vep)
> +{
> + /* Only port 0 endpoint 0 is valid. */
> + if (vep->base.port || vep->base.id)
> + return -ENOTCONN;
> +
> + csi2->lanes = vep->bus.mipi_csi2.num_data_lanes;
> +
> + return 0;
> +}
> +
> +static int rzg2l_csi2_parse_dt(struct rzg2l_csi2 *csi2)
> +{
> + struct v4l2_fwnode_endpoint v4l2_ep = {
> + .bus_type = V4L2_MBUS_CSI2_DPHY
> + };
> + struct v4l2_async_subdev *asd;
> + struct fwnode_handle *fwnode;
> + struct fwnode_handle *ep;
> + int ret;
> +
> + ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi2->dev), 0, 0, 0);
> + if (!ep) {
> + dev_err(csi2->dev, "Not connected to subdevice\n");
> + return -EINVAL;
> + }
> +
> + ret = v4l2_fwnode_endpoint_parse(ep, &v4l2_ep);
> + if (ret) {
> + dev_err(csi2->dev, "Could not parse v4l2 endpoint\n");
> + fwnode_handle_put(ep);
> + return -EINVAL;
> + }
> +
> + ret = rzg2l_csi2_parse_v4l2(csi2, &v4l2_ep);
> + if (ret) {
> + fwnode_handle_put(ep);
> + return ret;
> + }
> +
> + fwnode = fwnode_graph_get_remote_endpoint(ep);
> + fwnode_handle_put(ep);
> +
> + v4l2_async_nf_init(&csi2->notifier);
> + csi2->notifier.ops = &rzg2l_csi2_notify_ops;
> +
> + asd = v4l2_async_nf_add_fwnode(&csi2->notifier, fwnode,
> + struct v4l2_async_subdev);
> + fwnode_handle_put(fwnode);
> + if (IS_ERR(asd))
> + return PTR_ERR(asd);
> +
> + ret = v4l2_async_subdev_nf_register(&csi2->subdev, &csi2->notifier);
> + if (ret)
> + v4l2_async_nf_cleanup(&csi2->notifier);
> +
> + return ret;
> +}
> +
> +static int rzg2l_validate_csi2_lanes(struct rzg2l_csi2 *csi2)
> +{
> + int ret = 0;
> + int lanes;
> +
> + if (csi2->lanes != 1 && csi2->lanes != 2 && csi2->lanes != 4) {
> + dev_err(csi2->dev, "Unsupported number of data-lanes: %u\n",
> + csi2->lanes);
> + return -EINVAL;
> + }
> +
> + ret = rzg2l_csi2_enable_reg_access(csi2);
> + if (ret < 0)
> + return ret;
> +
> + /* Checking the maximum lanes support for CSI-2 module */
> + lanes = (rzg2l_csi2_read(csi2, CSI2nMCG) & CSI2nMCG_SDLN) >> 8;
> + if (lanes < csi2->lanes) {
> + dev_err(csi2->dev,
> + "Failed to support %d data lanes\n", csi2->lanes);
> + ret = -EINVAL;
> + }
> +
> + rzg2l_csi2_disable_reg_access(csi2);
> +
> + return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Platform Device Driver.
> + */
> +
> +static const struct media_entity_operations rzg2l_csi2_entity_ops = {
> + .link_validate = v4l2_subdev_link_validate,
> +};
> +
> +static int rzg2l_csi2_probe(struct platform_device *pdev)
> +{
> + struct rzg2l_csi2 *csi2;
> + struct clk *vclk;
> + int ret;
> +
> + csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
> + if (!csi2)
> + return -ENOMEM;
> +
> + csi2->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(csi2->base))
> + return PTR_ERR(csi2->base);
> +
> + csi2->cmn_rstb = devm_reset_control_get_exclusive(&pdev->dev, "cmn-rstb");
> + if (IS_ERR(csi2->cmn_rstb))
> + return dev_err_probe(&pdev->dev, PTR_ERR(csi2->cmn_rstb),
> + "Failed to get cpg cmn-rstb\n");
> +
> + csi2->presetn = devm_reset_control_get_shared(&pdev->dev, "presetn");

Is this really a shared reset control, or do you use the shared API only
to enable reference counting of the reset controller ?

> + if (IS_ERR(csi2->presetn))
> + return dev_err_probe(&pdev->dev, PTR_ERR(csi2->presetn),
> + "Failed to get cpg presetn\n");
> +
> + csi2->sysclk = devm_clk_get(&pdev->dev, "system");
> + if (IS_ERR(csi2->sysclk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(csi2->sysclk),
> + "Failed to get system clk\n");
> +
> + vclk = clk_get(&pdev->dev, "video");
> + if (IS_ERR(vclk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(vclk),
> + "Failed to get video clock\n");
> + csi2->vclk_rate = clk_get_rate(vclk);
> + clk_put(vclk);
> +
> + csi2->dev = &pdev->dev;
> +
> + platform_set_drvdata(pdev, csi2);
> +
> + ret = rzg2l_csi2_parse_dt(csi2);
> + if (ret)
> + return ret;
> +
> + pm_runtime_enable(&pdev->dev);
> +
> + ret = rzg2l_validate_csi2_lanes(csi2);
> + if (ret)
> + goto error_pm;
> +
> + csi2->subdev.dev = &pdev->dev;
> + v4l2_subdev_init(&csi2->subdev, &rzg2l_csi2_subdev_ops);
> + v4l2_set_subdevdata(&csi2->subdev, &pdev->dev);
> + snprintf(csi2->subdev.name, sizeof(csi2->subdev.name),
> + "csi-%s", dev_name(&pdev->dev));
> + csi2->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> + csi2->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> + csi2->subdev.entity.ops = &rzg2l_csi2_entity_ops;
> +
> + csi2->pads[RZG2L_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
> + /*
> + * TODO: RZ/G2L CSI2 supports 4 virtual channels, as virtual
> + * channels should be implemented by streams API which is under
> + * development lets hardcode to VC0 for now.
> + */
> + csi2->pads[RZG2L_CSI2_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> + ret = media_entity_pads_init(&csi2->subdev.entity, 2, csi2->pads);
> + if (ret)
> + goto error_pm;
> +
> + ret = v4l2_subdev_init_finalize(&csi2->subdev);
> + if (ret < 0)
> + goto error_async;
> +
> + ret = v4l2_async_register_subdev(&csi2->subdev);
> + if (ret < 0)
> + goto error_subdev;
> +
> + return 0;
> +
> +error_subdev:
> + v4l2_subdev_cleanup(&csi2->subdev);
> +error_async:
> + v4l2_async_nf_unregister(&csi2->notifier);
> + v4l2_async_nf_cleanup(&csi2->notifier);
> + media_entity_cleanup(&csi2->subdev.entity);
> +error_pm:
> + pm_runtime_disable(&pdev->dev);
> +
> + return ret;
> +}
> +
> +static int rzg2l_csi2_remove(struct platform_device *pdev)
> +{
> + struct rzg2l_csi2 *csi2 = platform_get_drvdata(pdev);
> +
> + v4l2_async_nf_unregister(&csi2->notifier);
> + v4l2_async_nf_cleanup(&csi2->notifier);
> + v4l2_async_unregister_subdev(&csi2->subdev);
> + v4l2_subdev_cleanup(&csi2->subdev);
> + media_entity_cleanup(&csi2->subdev.entity);
> + pm_runtime_disable(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id rzg2l_csi2_of_table[] = {
> + { .compatible = "renesas,rzg2l-csi2", },
> + { /* sentinel */ }
> +};
> +
> +static struct platform_driver rzg2l_csi2_pdrv = {
> + .remove = rzg2l_csi2_remove,
> + .probe = rzg2l_csi2_probe,
> + .driver = {
> + .name = "rzg2l-csi2",
> + .of_match_table = rzg2l_csi2_of_table,
> + },
> +};
> +
> +module_platform_driver(rzg2l_csi2_pdrv);
> +
> +MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Renesas RZ/G2L MIPI CSI2 receiver driver");
> +MODULE_LICENSE("GPL");

--
Regards,

Laurent Pinchart