Re: [PATCH v2 4/4] media: tc358746: add Toshiba TC358746 Parallel to CSI-2 bridge driver
From: Laurent Pinchart
Date: Mon Sep 19 2022 - 13:37:49 EST
Hi Marco,
On Mon, Sep 19, 2022 at 07:11:42PM +0200, Marco Felsch wrote:
> On 22-09-19, Laurent Pinchart wrote:
> > On Fri, Sep 16, 2022 at 03:45:35PM +0200, Marco Felsch wrote:
> > > Adding support for the TC358746 parallel <-> MIPI CSI bridge. This chip
> > > supports two operating modes:
> > > 1st) parallel-in -> mipi-csi out
> > > 2nd) mipi-csi in -> parallel out
> > >
> > > This patch only adds the support for the 1st mode.
> > >
> > > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> > > ---
> > > Changelog:
> > >
> > > v2:
> > > - use the correct CID_LINK_FREQ control to query the sensor_pclk_rate
> > > - remove now not needed tc358746_link_setup() and
> > > struct v4l2_ctrl sensor_pclk_ctrl
> > > - call v4l2_subdev_link_validate_default() during link validation
> > > - remove MEDIA_BUS_FMT_GBR888_1X24/YUV444 format support
> > > - use subdev active_state API
> > > - replace own .get_fmt with v4l2_subdev_get_fmt
> > > - remove unnecessary pad checks
> > > - restructure tc358746_get_format_by_code() if-case
> > > - move apply_dphy_config|apply_misc_config from resume intos s_stream
> > > - use goto in s_stream enable case
> > > - fix error handling in suspend/resume
> > > - split probe() into more sub-functions
> > > - use dev_dbg() for printing successful probe
> > >
> > > drivers/media/i2c/Kconfig | 17 +
> > > drivers/media/i2c/Makefile | 1 +
> > > drivers/media/i2c/tc358746.c | 1682 ++++++++++++++++++++++++++++++++++
> > > 3 files changed, 1700 insertions(+)
> > > create mode 100644 drivers/media/i2c/tc358746.c
> > >
> > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > > index 7806d4b81716..aefb9c9e0c08 100644
> > > --- a/drivers/media/i2c/Kconfig
> > > +++ b/drivers/media/i2c/Kconfig
> > > @@ -1272,6 +1272,23 @@ config VIDEO_TC358743_CEC
> > > When selected the tc358743 will support the optional
> > > HDMI CEC feature.
> > >
> > > +config VIDEO_TC358746
> > > + tristate "Toshiba TC358746 parallel-CSI2 bridge"
> > > + depends on VIDEO_DEV && I2C
> > > + select VIDEO_V4L2_SUBDEV_API
> > > + select MEDIA_CONTROLLER
> > > + select V4L2_FWNODE
> > > + select GENERIC_PHY_MIPI_DPHY
> > > + select REGMAP_I2C
> > > + select COMMON_CLK
> > > + help
> > > + Support for the Toshiba TC358746 parallel to MIPI CSI-2 bridge.
> > > + The bridge can work in both directions but currently only the
> > > + parallel-in / csi-out path is supported.
> > > +
> > > + To compile this driver as a module, choose M here: the
> > > + module will be called tc358746.
> > > +
> > > config VIDEO_TVP514X
> > > tristate "Texas Instruments TVP514x video decoder"
> > > depends on VIDEO_DEV && I2C
> > > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > > index 0a2933103dd9..d1096c2ab480 100644
> > > --- a/drivers/media/i2c/Makefile
> > > +++ b/drivers/media/i2c/Makefile
> > > @@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
> > > obj-$(CONFIG_VIDEO_SR030PC30) += sr030pc30.o
> > > obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
> > > obj-$(CONFIG_VIDEO_TC358743) += tc358743.o
> > > +obj-$(CONFIG_VIDEO_TC358746) += tc358746.o
> > > obj-$(CONFIG_VIDEO_TDA1997X) += tda1997x.o
> > > obj-$(CONFIG_VIDEO_TDA7432) += tda7432.o
> > > obj-$(CONFIG_VIDEO_TDA9840) += tda9840.o
> > > diff --git a/drivers/media/i2c/tc358746.c b/drivers/media/i2c/tc358746.c
> > > new file mode 100644
> > > index 000000000000..4f1a809b9fc3
> > > --- /dev/null
> > > +++ b/drivers/media/i2c/tc358746.c
> > > @@ -0,0 +1,1682 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * TC358746 - Parallel <-> CSI-2 Bridge
> > > + *
> > > + * Copyright 2022 Marco Felsch <kernel@xxxxxxxxxxxxxx>
> > > + *
> > > + * Notes:
> > > + * - Currently only 'Parallel-in -> CSI-out' mode is supported!
> > > + */
> > > +
> > > +#include <linux/bitfield.h>
> > > +#include <linux/clk.h>
> > > +#include <linux/clk-provider.h>
> > > +#include <linux/delay.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/module.h>
> > > +#include <linux/phy/phy-mipi-dphy.h>
> > > +#include <linux/property.h>
> > > +#include <linux/pm_runtime.h>
> > > +#include <linux/regmap.h>
> > > +#include <media/v4l2-ctrls.h>
> > > +#include <media/v4l2-device.h>
> > > +#include <media/v4l2-fwnode.h>
> > > +#include <media/v4l2-mc.h>
> > > +
> > > +/* 16-bit registers */
> > > +#define CHIPID_REG 0x0000
> > > +#define CHIPID GENMASK(15, 8)
> > > +
> > > +#define SYSCTL_REG 0x0002
> > > +#define SRESET BIT(0)
> > > +
> > > +#define CONFCTL_REG 0x0004
> > > +#define PDATAF_MASK GENMASK(9, 8)
> > > +#define PDATAF_MODE0 0
> > > +#define PDATAF_MODE1 1
> > > +#define PDATAF_MODE2 2
> > > +#define PDATAF(val) FIELD_PREP(PDATAF_MASK, (val))
> > > +#define PPEN BIT(6)
> > > +#define DATALANE_MASK GENMASK(1, 0)
> > > +
> > > +#define FIFOCTL_REG 0x0006
> > > +#define DATAFMT_REG 0x0008
> > > +#define PDFMT(val) FIELD_PREP(GENMASK(7, 4), (val))
> > > +
> > > +#define MCLKCTL_REG 0x000c
> > > +#define MCLK_HIGH_MASK GENMASK(15, 8)
> > > +#define MCLK_LOW_MASK GENMASK(7, 0)
> > > +#define MCLK_HIGH(val) FIELD_PREP(MCLK_HIGH_MASK, (val))
> > > +#define MCLK_LOW(val) FIELD_PREP(MCLK_LOW_MASK, (val))
> > > +
> > > +#define PLLCTL0_REG 0x0016
> > > +#define PLL_PRD_MASK GENMASK(15, 12)
> > > +#define PLL_PRD(val) FIELD_PREP(PLL_PRD_MASK, (val))
> > > +#define PLL_FBD_MASK GENMASK(8, 0)
> > > +#define PLL_FBD(val) FIELD_PREP(PLL_FBD_MASK, (val))
> > > +
> > > +#define PLLCTL1_REG 0x0018
> > > +#define PLL_FRS_MASK GENMASK(11, 10)
> > > +#define PLL_FRS(val) FIELD_PREP(PLL_FRS_MASK, (val))
> > > +#define CKEN BIT(4)
> > > +#define RESETB BIT(1)
> > > +#define PLL_EN BIT(0)
> > > +
> > > +#define CLKCTL_REG 0x0020
> > > +#define MCLKDIV_MASK GENMASK(3, 2)
> > > +#define MCLKDIV(val) FIELD_PREP(MCLKDIV_MASK, (val))
> > > +#define MCLKDIV_8 0
> > > +#define MCLKDIV_4 1
> > > +#define MCLKDIV_2 2
> > > +
> > > +#define WORDCNT_REG 0x0022
> > > +#define PP_MISC_REG 0x0032
> > > +#define FRMSTOP BIT(15)
> > > +#define RSTPTR BIT(14)
> > > +
> > > +/* 32-bit registers */
> > > +#define CLW_DPHYCONTTX_REG 0x0100
> > > +#define CLW_CNTRL_REG 0x0140
> > > +#define D0W_CNTRL_REG 0x0144
> > > +#define LANEDISABLE BIT(0)
> > > +
> > > +#define STARTCNTRL_REG 0x0204
> > > +#define START BIT(0)
> > > +
> > > +#define LINEINITCNT_REG 0x0210
> > > +#define LPTXTIMECNT_REG 0x0214
> > > +#define TCLK_HEADERCNT_REG 0x0218
> > > +#define TCLK_ZEROCNT(val) FIELD_PREP(GENMASK(15, 8), (val))
> > > +#define TCLK_PREPARECNT(val) FIELD_PREP(GENMASK(6, 0), (val))
> > > +
> > > +#define TCLK_TRAILCNT_REG 0x021C
> > > +#define THS_HEADERCNT_REG 0x0220
> > > +#define THS_ZEROCNT(val) FIELD_PREP(GENMASK(14, 8), (val))
> > > +#define THS_PREPARECNT(val) FIELD_PREP(GENMASK(6, 0), (val))
> > > +
> > > +#define TWAKEUP_REG 0x0224
> > > +#define TCLK_POSTCNT_REG 0x0228
> > > +#define THS_TRAILCNT_REG 0x022C
> > > +#define HSTXVREGEN_REG 0x0234
> > > +#define TXOPTIONCNTRL_REG 0x0238
> > > +#define CSI_CONTROL_REG 0x040C
> > > +#define CSI_MODE BIT(15)
> > > +#define TXHSMD BIT(7)
> > > +#define NOL(val) FIELD_PREP(GENMASK(2, 1), (val))
> > > +
> > > +#define CSI_CONFW_REG 0x0500
> > > +#define MODE(val) FIELD_PREP(GENMASK(31, 29), (val))
> > > +#define MODE_SET 0x5
> > > +#define ADDRESS(val) FIELD_PREP(GENMASK(28, 24), (val))
> > > +#define CSI_CONTROL_ADDRESS 0x3
> > > +#define DATA(val) FIELD_PREP(GENMASK(15, 0), (val))
> > > +
> > > +#define CSI_START_REG 0x0518
> > > +#define STRT BIT(0)
> > > +
> > > +static const struct v4l2_mbus_framefmt tc358746_def_fmt = {
> > > + .width = 640,
> > > + .height = 480,
> > > + .code = MEDIA_BUS_FMT_UYVY8_2X8,
> > > + .field = V4L2_FIELD_NONE,
> > > + .colorspace = V4L2_COLORSPACE_DEFAULT,
> > > + .ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT,
> > > + .quantization = V4L2_QUANTIZATION_DEFAULT,
> > > + .xfer_func = V4L2_XFER_FUNC_DEFAULT,
> > > +};
> > > +
> > > +static const char * const tc358746_supplies[] = {
> > > + "vddc", "vddio", "vddmipi"
> > > +};
> > > +
> > > +enum {
> > > + TC358746_SINK,
> > > + TC358746_SOURCE,
> > > + TC358746_NR_PADS
> > > +};
> > > +
> > > +struct tc358746 {
> > > + struct v4l2_subdev sd;
> > > + struct media_pad pads[TC358746_NR_PADS];
> > > + struct v4l2_async_notifier notifier;
> > > + struct v4l2_fwnode_endpoint csi_vep;
> > > +
> > > + struct v4l2_ctrl_handler ctrl_hdl;
> > > +
> > > + struct regmap *regmap;
> > > + struct clk *refclk;
> > > + struct gpio_desc *reset_gpio;
> > > + struct regulator_bulk_data supplies[ARRAY_SIZE(tc358746_supplies)];
> > > +
> > > + struct clk_hw mclk_hw;
> > > + unsigned long mclk_rate;
> > > + u8 mclk_prediv;
> > > + u16 mclk_postdiv;
> > > +
> > > + unsigned long pll_rate;
> > > + u8 pll_post_div;
> > > + u16 pll_pre_div;
> > > + u16 pll_mul;
> > > +
> > > +#define TC358746_VB_MAX_SIZE (511 * 32)
> > > +#define TC358746_VB_DEFAULT_SIZE (1 * 32)
> > > + unsigned int vb_size; /* Video buffer size in bits */
> > > +
> > > + struct phy_configure_opts_mipi_dphy dphy_cfg;
> > > +};
> > > +
> > > +static inline struct tc358746 *to_tc358746(struct v4l2_subdev *sd)
> > > +{
> > > + return container_of(sd, struct tc358746, sd);
> > > +}
> > > +
> > > +static inline struct tc358746 *clk_hw_to_tc358746(struct clk_hw *hw)
> > > +{
> > > + return container_of(hw, struct tc358746, mclk_hw);
> > > +}
> > > +
> > > +struct tc358746_format {
> > > + u32 code;
> > > + bool csi_format;
> > > + unsigned char bus_width;
> > > + unsigned char bpp;
> > > + /* Register values */
> > > + u8 pdformat; /* Peripheral Data Format */
> > > + u8 pdataf; /* Parallel Data Format Option */
> > > +};
> > > +
> > > +enum {
> > > + PDFORMAT_RAW8 = 0,
> > > + PDFORMAT_RAW10,
> > > + PDFORMAT_RAW12,
> > > + PDFORMAT_RGB888,
> > > + PDFORMAT_RGB666,
> > > + PDFORMAT_RGB565,
> > > + PDFORMAT_YUV422_8BIT,
> > > + /* RESERVED = 7 */
> > > + PDFORMAT_RAW14 = 8,
> > > + PDFORMAT_YUV422_10BIT,
> > > + PDFORMAT_YUV444,
> > > +};
> > > +
> > > +/* Check tc358746_src_mbus_code() if you add new formats */
> > > +static const struct tc358746_format tc358746_formats[] = {
> > > + {
> > > + .code = MEDIA_BUS_FMT_UYVY8_2X8,
> > > + .bus_width = 8,
> > > + .bpp = 16,
> > > + .pdformat = PDFORMAT_YUV422_8BIT,
> > > + .pdataf = PDATAF_MODE0,
> > > + }, {
> > > + .code = MEDIA_BUS_FMT_UYVY8_1X16,
> > > + .csi_format = true,
> > > + .bus_width = 16,
> > > + .bpp = 16,
> > > + .pdformat = PDFORMAT_YUV422_8BIT,
> > > + .pdataf = PDATAF_MODE1,
> > > + }, {
> > > + .code = MEDIA_BUS_FMT_YUYV8_1X16,
> > > + .csi_format = true,
> > > + .bus_width = 16,
> > > + .bpp = 16,
> > > + .pdformat = PDFORMAT_YUV422_8BIT,
> > > + .pdataf = PDATAF_MODE2,
> > > + }, {
> > > + .code = MEDIA_BUS_FMT_UYVY10_2X10,
> > > + .bus_width = 10,
> > > + .bpp = 20,
> > > + .pdformat = PDFORMAT_YUV422_10BIT,
> > > + .pdataf = PDATAF_MODE0, /* don't care */
> > > + }
> > > +};
> > > +
> > > +/* Get n-th format for pad */
> > > +static const struct tc358746_format *
> > > +tc358746_get_format_by_idx(unsigned int pad, unsigned int index)
> > > +{
> > > + unsigned int idx = 0;
> > > + unsigned int i;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > > + const struct tc358746_format *fmt = &tc358746_formats[i];
> > > +
> > > + if ((pad == TC358746_SOURCE && fmt->csi_format) ||
> > > + (pad == TC358746_SINK)) {
> > > + if (idx == index)
> > > + return fmt;
> > > + idx++;
> > > + }
> > > + }
> > > +
> > > + return ERR_PTR(-EINVAL);
> > > +}
> > > +
> > > +static const struct tc358746_format *
> > > +tc358746_get_format_by_code(unsigned int pad, u32 code)
> > > +{
> > > + unsigned int i;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(tc358746_formats); i++) {
> > > + const struct tc358746_format *fmt = &tc358746_formats[i];
> > > +
> > > + if (pad == TC358746_SINK && fmt->code == code)
> > > + return fmt;
> > > +
> > > + if (pad == TC358746_SOURCE && !fmt->csi_format)
> > > + continue;
> > > +
> > > + if (fmt->code == code)
> > > + return fmt;
> > > + }
> > > +
> > > + return ERR_PTR(-EINVAL);
> > > +}
> > > +
> > > +static u32 tc358746_src_mbus_code(u32 code)
> > > +{
> > > + switch (code) {
> > > + case MEDIA_BUS_FMT_UYVY8_2X8:
> > > + return MEDIA_BUS_FMT_UYVY8_1X16;
> > > + case MEDIA_BUS_FMT_UYVY10_2X10:
> > > + return MEDIA_BUS_FMT_UYVY10_1X20;
> > > + default:
> > > + return code;
> > > + }
> > > +}
> > > +
> > > +static bool tc358746_writeable_reg(struct device *dev, unsigned int reg)
> > > +{
> > > + switch (reg) {
> > > + case SYSCTL_REG ... CSI_START_REG:
> > > + return true;
> > > + default:
> > > + return false;
> > > + }
> > > +}
> > > +
> > > +static bool tc358746_readable_reg(struct device *dev, unsigned int reg)
> > > +{
> > > + switch (reg) {
> > > + case CHIPID_REG ... CSI_START_REG:
> > > + return true;
> > > + default:
> > > + return false;
> > > + }
> > > +}
> > > +
> > > +static const struct regmap_config tc358746_regmap_config = {
> > > + .name = "tc358746",
> > > + .reg_bits = 16,
> > > + .val_bits = 16,
> > > + .max_register = CSI_START_REG,
> > > + .writeable_reg = tc358746_writeable_reg,
> > > + .readable_reg = tc358746_readable_reg,
> > > + .reg_format_endian = REGMAP_ENDIAN_BIG,
> > > + .val_format_endian = REGMAP_ENDIAN_BIG,
> > > +};
> > > +
> > > +static int tc358746_write(struct tc358746 *tc358746, u32 reg, u32 val)
> > > +{
> > > + size_t count;
> > > +
> > > + /* 32-bit registers starting from CLW_DPHYCONTTX */
> > > + count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > +
> > > + return regmap_bulk_write(tc358746->regmap, reg, &val, count);
> > > +}
> > > +
> > > +static int tc358746_read(struct tc358746 *tc358746, u32 reg, u32 *val)
> > > +{
> > > + size_t count;
> > > +
> > > + /* 32-bit registers starting from CLW_DPHYCONTTX */
> > > + count = reg < CLW_DPHYCONTTX_REG ? 1 : 2;
> > > + *val = 0;
> > > +
> > > + return regmap_bulk_read(tc358746->regmap, reg, val, count);
> > > +}
> > > +
> > > +static int
> > > +tc358746_update_bits(struct tc358746 *tc358746, u32 reg, u32 mask, u32 val)
> > > +{
> > > + u32 tmp, orig;
> > > + int err;
> > > +
> > > + err = tc358746_read(tc358746, reg, &orig);
> > > + if (err)
> > > + return err;
> > > +
> > > + tmp = orig & ~mask;
> > > + tmp |= val & mask;
> > > +
> > > + return tc358746_write(tc358746, reg, tmp);
> > > +}
> > > +
> > > +static int tc358746_set_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > > +{
> > > + return tc358746_update_bits(tc358746, reg, bits, bits);
> > > +}
> > > +
> > > +static int tc358746_clear_bits(struct tc358746 *tc358746, u32 reg, u32 bits)
> > > +{
> > > + return tc358746_update_bits(tc358746, reg, bits, 0);
> > > +}
> > > +
> > > +static int tc358746_sw_reset(struct tc358746 *tc358746)
> > > +{
> > > + int err;
> > > +
> > > + err = tc358746_set_bits(tc358746, SYSCTL_REG, SRESET);
> > > + if (err)
> > > + return err;
> > > +
> > > + udelay(10);
> > > +
> > > + return tc358746_clear_bits(tc358746, SYSCTL_REG, SRESET);
> > > +}
> > > +
> > > +static int
> > > +tc358746_apply_pll_config(struct tc358746 *tc358746)
> > > +{
> > > + u8 post = tc358746->pll_post_div;
> > > + u16 pre = tc358746->pll_pre_div;
> > > + u16 mul = tc358746->pll_mul;
> > > + u32 val, mask;
> > > + int err;
> > > +
> > > + err = tc358746_read(tc358746, PLLCTL1_REG, &val);
> > > + if (err)
> > > + return err;
> > > +
> > > + /* Don't touch the PLL if running */
> > > + if (FIELD_GET(PLL_EN, val) == 1)
> > > + return 0;
> > > +
> > > + /* Pre-div and Multiplicator have a internal +1 logic */
> > > + val = PLL_PRD(pre - 1) | PLL_FBD(mul - 1);
> > > + mask = PLL_PRD_MASK | PLL_FBD_MASK;
> > > + err = tc358746_update_bits(tc358746, PLLCTL0_REG, mask, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = PLL_FRS(ilog2(post)) | RESETB | PLL_EN;
> > > + mask = PLL_FRS_MASK | RESETB | PLL_EN;
> > > + tc358746_update_bits(tc358746, PLLCTL1_REG, mask, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + udelay(1000);
> > > +
> > > + return tc358746_set_bits(tc358746, PLLCTL1_REG, CKEN);
> > > +}
> > > +
> > > +static int tc358746_apply_misc_config(struct tc358746 *tc358746)
> > > +{
> > > + struct v4l2_subdev *sd = &tc358746->sd;
> > > + struct v4l2_subdev_state *sink_state;
> > > + struct v4l2_mbus_framefmt *mbusfmt;
> >
> > This can be const.
>
> Sure
>
> > > + const struct tc358746_format *fmt;
> > > + struct device *dev = sd->dev;
> > > + u32 val;
> > > + int err;
> > > +
> > > + sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> > > + mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > > + v4l2_subdev_unlock_state(sink_state);
> >
> > You should keep the state locked until the end of this function,
> > otherwise the format could change.
>
> That couldn't be the case since this function is called during
> .s_stream(on) and my understanding was that it is not allowed to change
> the active format after calling .s_stream(on). But I can move it to the
> end.
You're right, my bad. I can't wait for the .enable_streams() and
.disable_streams() operations to replace .s_stream(), the state will
then be passed by the framework to the drivers, simplifying all this.
> > > + fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > > +
> > > + /* Self defined CSI user data type id's are not supported yet */
> > > + val = PDFMT(fmt->pdformat);
> > > + dev_dbg(dev, "DATAFMT: 0x%x\n", val);
> > > + err = tc358746_write(tc358746, DATAFMT_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = PDATAF(fmt->pdataf);
> > > + dev_dbg(dev, "CONFCTL[PDATAF]: 0x%x\n", fmt->pdataf);
> > > + err = tc358746_update_bits(tc358746, CONFCTL_REG, PDATAF_MASK, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746->vb_size / 32;
> > > + dev_dbg(dev, "FIFOCTL: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, FIFOCTL_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + /* Total number of bytes for each line/width */
> > > + val = mbusfmt->width * fmt->bpp / 8;
> > > + dev_dbg(dev, "WORDCNT: %u (0x%x)\n", val, val);
> > > + return tc358746_write(tc358746, WORDCNT_REG, val);
> > > +}
> > > +
> > > +#ifndef MHZ
> > > +#define MHZ (1000 * 1000)
> > > +#endif
> > > +
> > > +/* Use MHz as base so the div needs no u64 */
> > > +static u32 tc358746_cfg_to_cnt(unsigned int cfg_val,
> > > + unsigned int clk_mhz,
> > > + unsigned int time_base)
> > > +{
> > > + return DIV_ROUND_UP(cfg_val * clk_mhz, time_base);
> > > +}
> > > +
> > > +static u32 tc358746_ps_to_cnt(unsigned int cfg_val,
> > > + unsigned int clk_mhz)
> > > +{
> > > + return tc358746_cfg_to_cnt(cfg_val, clk_mhz, USEC_PER_SEC);
> > > +}
> > > +
> > > +static u32 tc358746_us_to_cnt(unsigned int cfg_val,
> > > + unsigned int clk_mhz)
> > > +{
> > > + return tc358746_cfg_to_cnt(cfg_val, clk_mhz, 1);
> > > +}
> > > +
> > > +static int tc358746_apply_dphy_config(struct tc358746 *tc358746)
> > > +{
> > > + struct phy_configure_opts_mipi_dphy *cfg = &tc358746->dphy_cfg;
> > > + bool non_cont_clk = !!(tc358746->csi_vep.bus.mipi_csi2.flags &
> > > + V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK);
> > > + struct device *dev = tc358746->sd.dev;
> > > + unsigned long hs_byte_clk, hf_clk;
> > > + u32 val, val2, lptxcnt;
> > > + int err;
> > > +
> > > + /* The hs_byte_clk is also called SYSCLK in the excel sheet */
> > > + hs_byte_clk = cfg->hs_clk_rate / 8;
> > > + hs_byte_clk /= MHZ;
> > > + hf_clk = hs_byte_clk / 2;
> > > +
> > > + val = tc358746_us_to_cnt(cfg->init, hf_clk) - 1;
> > > + dev_dbg(dev, "LINEINITCNT: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, LINEINITCNT_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746_ps_to_cnt(cfg->lpx, hs_byte_clk) - 1;
> > > + lptxcnt = val;
> > > + dev_dbg(dev, "LPTXTIMECNT: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, LPTXTIMECNT_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746_ps_to_cnt(cfg->clk_prepare, hs_byte_clk) - 1;
> > > + val2 = tc358746_ps_to_cnt(cfg->clk_zero, hs_byte_clk) - 1;
> > > + dev_dbg(dev, "TCLK_PREPARECNT: %u (0x%x)\n", val, val);
> > > + dev_dbg(dev, "TCLK_ZEROCNT: %u (0x%x)\n", val2, val2);
> > > + dev_dbg(dev, "TCLK_HEADERCNT: 0x%x\n",
> > > + (u32)(TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2)));
> > > + err = tc358746_write(tc358746, TCLK_HEADERCNT_REG,
> > > + TCLK_PREPARECNT(val) | TCLK_ZEROCNT(val2));
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746_ps_to_cnt(cfg->clk_trail, hs_byte_clk);
> > > + dev_dbg(dev, "TCLK_TRAILCNT: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, TCLK_TRAILCNT_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746_ps_to_cnt(cfg->hs_prepare, hs_byte_clk) - 1;
> > > + val2 = tc358746_ps_to_cnt(cfg->hs_zero, hs_byte_clk) - 1;
> > > + dev_dbg(dev, "THS_PREPARECNT: %u (0x%x)\n", val, val);
> > > + dev_dbg(dev, "THS_ZEROCNT: %u (0x%x)\n", val2, val2);
> > > + dev_dbg(dev, "THS_HEADERCNT: 0x%x\n",
> > > + (u32)(THS_PREPARECNT(val) | THS_ZEROCNT(val2)));
> > > + err = tc358746_write(tc358746, THS_HEADERCNT_REG,
> > > + THS_PREPARECNT(val) | THS_ZEROCNT(val2));
> > > + if (err)
> > > + return err;
> > > +
> > > + /* TWAKEUP > 1ms in lptxcnt steps */
> > > + val = tc358746_us_to_cnt(cfg->wakeup, hs_byte_clk);
> > > + val = val / (lptxcnt + 1) - 1;
> > > + dev_dbg(dev, "TWAKEUP: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, TWAKEUP_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746_ps_to_cnt(cfg->clk_post, hs_byte_clk);
> > > + dev_dbg(dev, "TCLK_POSTCNT: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, TCLK_POSTCNT_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + val = tc358746_ps_to_cnt(cfg->hs_trail, hs_byte_clk);
> > > + dev_dbg(dev, "THS_TRAILCNT: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, THS_TRAILCNT_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + dev_dbg(dev, "CONTCLKMODE: %u", non_cont_clk ? 0 : 1);
> > > + return tc358746_write(tc358746, TXOPTIONCNTRL_REG, non_cont_clk ? 0 : 1);
> > > +}
> > > +
> > > +#define MAX_DATA_LANES 4
> > > +
> > > +static int tc358746_enable_csi_lanes(struct tc358746 *tc358746, int enable)
> > > +{
> > > + unsigned int lanes = tc358746->dphy_cfg.lanes;
> > > + unsigned int lane;
> > > + u32 reg, val;
> > > + int err;
> > > +
> > > + err = tc358746_update_bits(tc358746, CONFCTL_REG, DATALANE_MASK,
> > > + lanes - 1);
> > > + if (err)
> > > + return err;
> > > +
> > > + /* Clock lane */
> > > + val = enable ? 0 : LANEDISABLE;
> > > + dev_dbg(tc358746->sd.dev, "CLW_CNTRL: 0x%x\n", val);
> > > + err = tc358746_write(tc358746, CLW_CNTRL_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + for (lane = 0; lane < MAX_DATA_LANES; lane++) {
> > > + /* Data lanes */
> > > + reg = D0W_CNTRL_REG + lane * 0x4;
> > > + val = (enable && lane < lanes) ? 0 : LANEDISABLE;
> > > +
> > > + dev_dbg(tc358746->sd.dev, "D%uW_CNTRL: 0x%x\n", lane, val);
> > > + err = tc358746_write(tc358746, reg, val);
> > > + if (err)
> > > + return err;
> > > + }
> > > +
> > > + val = 0;
> > > + if (enable) {
> > > + /* Clock lane */
> > > + val |= BIT(0);
> > > +
> > > + /* Data lanes */
> > > + for (lane = 1; lane <= lanes; lane++)
> > > + val |= BIT(lane);
> > > + }
> > > +
> > > + dev_dbg(tc358746->sd.dev, "HSTXVREGEN: 0x%x\n", val);
> > > + return tc358746_write(tc358746, HSTXVREGEN_REG, val);
> > > +}
> > > +
> > > +static int tc358746_enable_csi_module(struct tc358746 *tc358746, int enable)
> > > +{
> > > + unsigned int lanes = tc358746->dphy_cfg.lanes;
> > > + int err;
> > > +
> > > + /*
> > > + * START and STRT are only reseted/disabled by sw reset. This is
> > > + * required to put the lane state back into LP-11 state. The sw reset
> > > + * don't reset register values.
> > > + */
> > > + if (!enable)
> > > + return tc358746_sw_reset(tc358746);
> > > +
> > > + err = tc358746_write(tc358746, STARTCNTRL_REG, START);
> > > + if (err)
> > > + return err;
> > > +
> > > + err = tc358746_write(tc358746, CSI_START_REG, STRT);
> > > + if (err)
> > > + return err;
> > > +
> > > + /* CSI_CONTROL_REG is only indirect accessible */
> > > + return tc358746_write(tc358746, CSI_CONFW_REG,
> > > + MODE(MODE_SET) |
> > > + ADDRESS(CSI_CONTROL_ADDRESS) |
> > > + DATA(CSI_MODE | TXHSMD | NOL(lanes - 1)));
> > > +}
> > > +
> > > +static int tc358746_enable_parallel_port(struct tc358746 *tc358746, int enable)
> > > +{
> > > + int err;
> > > +
> > > + if (enable) {
> > > + err = tc358746_write(tc358746, PP_MISC_REG, 0);
> > > + if (err)
> > > + return err;
> > > +
> > > + return tc358746_set_bits(tc358746, CONFCTL_REG, PPEN);
> > > + }
> > > +
> > > + err = tc358746_set_bits(tc358746, PP_MISC_REG, FRMSTOP);
> > > + if (err)
> > > + return err;
> > > +
> > > + err = tc358746_clear_bits(tc358746, CONFCTL_REG, PPEN);
> > > + if (err)
> > > + return err;
> > > +
> > > + return tc358746_set_bits(tc358746, PP_MISC_REG, RSTPTR);
> > > +}
> > > +
> > > +static inline struct v4l2_subdev *tc358746_get_remote_sd(struct media_pad *pad)
> > > +{
> > > + pad = media_pad_remote_pad_first(pad);
> > > + if (!pad)
> > > + return NULL;
> > > +
> > > + return media_entity_to_v4l2_subdev(pad->entity);
> > > +}
> > > +
> > > +static int tc358746_s_stream(struct v4l2_subdev *sd, int enable)
> > > +{
> > > + struct tc358746 *tc358746 = to_tc358746(sd);
> > > + struct v4l2_subdev *src;
> > > + int err;
> > > +
> > > + dev_dbg(sd->dev, "%sable\n", enable ? "en" : "dis");
> > > +
> > > + src = tc358746_get_remote_sd(&tc358746->pads[TC358746_SINK]);
> > > + if (!src)
> > > + return -EPIPE;
> > > +
> > > + if (enable) {
> > > + err = pm_runtime_resume_and_get(sd->dev);
> > > + if (err)
> > > + return err;
> > > +
> > > + err = tc358746_apply_dphy_config(tc358746);
> > > + if (err)
> > > + goto err_out;
> > > +
> > > + err = tc358746_apply_misc_config(tc358746);
> > > + if (err)
> > > + goto err_out;
> > > +
> > > + err = tc358746_enable_csi_lanes(tc358746, 1);
> > > + if (err)
> > > + goto err_out;
> > > +
> > > + err = tc358746_enable_csi_module(tc358746, 1);
> > > + if (err)
> > > + goto err_out;
> > > +
> > > + err = tc358746_enable_parallel_port(tc358746, 1);
> > > + if (err)
> > > + goto err_out;
> > > +
> > > + err = v4l2_subdev_call(src, video, s_stream, 1);
> > > + if (err)
> > > + goto err_out;
> > > +
> > > + return err;
> > > +
> > > +err_out:
> > > + pm_runtime_mark_last_busy(sd->dev);
> > > + pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > + return err;
> > > + }
> > > +
> > > + /*
> > > + * Lane disable trigger state change from LP-11 to LP-00
> > > + * therefore it must happen before the CSI modile is disabled.
> > > + */
> > > + err = tc358746_enable_csi_lanes(tc358746, 0);
> > > + if (err)
> > > + return err;
> > > +
> > > + err = tc358746_enable_csi_module(tc358746, 0);
> > > + if (err)
> > > + return err;
> > > +
> > > + err = tc358746_enable_parallel_port(tc358746, 0);
> > > + if (err)
> > > + return err;
> > > +
> > > + pm_runtime_mark_last_busy(sd->dev);
> > > + pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > + return v4l2_subdev_call(src, video, s_stream, 0);
> > > +}
> > > +
> > > +static int tc358746_init_cfg(struct v4l2_subdev *sd,
> > > + struct v4l2_subdev_state *state)
> > > +{
> > > + struct v4l2_mbus_framefmt *fmt;
> > > +
> > > + fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SINK);
> > > + *fmt = tc358746_def_fmt;
> > > +
> > > + fmt = v4l2_subdev_get_pad_format(sd, state, TC358746_SOURCE);
> > > + *fmt = tc358746_def_fmt;
> > > + fmt->code = tc358746_src_mbus_code(tc358746_def_fmt.code);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int tc358746_enum_mbus_code(struct v4l2_subdev *sd,
> > > + struct v4l2_subdev_state *sd_state,
> > > + struct v4l2_subdev_mbus_code_enum *code)
> > > +{
> > > + const struct tc358746_format *fmt;
> > > +
> > > + fmt = tc358746_get_format_by_idx(code->pad, code->index);
> > > + if (IS_ERR(fmt))
> > > + return PTR_ERR(fmt);
> > > +
> > > + code->code = fmt->code;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int tc358746_set_fmt(struct v4l2_subdev *sd,
> > > + struct v4l2_subdev_state *sd_state,
> > > + struct v4l2_subdev_format *format)
> > > +{
> > > + struct v4l2_mbus_framefmt *src_fmt, *sink_fmt;
> > > + const struct tc358746_format *fmt;
> > > +
> > > + /* Source follows the sink */
> > > + if (format->pad == TC358746_SOURCE)
> > > + return 0;
> >
> > You need to get the source pad format here and copy it to format,
> > otherwise userspace will think whatever format it has passed has been
> > accepted.
>
> That's right, I will change that. Thanks.
>
> > > + sink_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SINK);
> > > +
> > > + fmt = tc358746_get_format_by_code(format->pad, format->format.code);
> > > + if (IS_ERR(fmt))
> > > + fmt = tc358746_get_format_by_code(format->pad, tc358746_def_fmt.code);
> > > +
> > > + format->format.code = fmt->code;
> > > + format->format.field = V4L2_FIELD_NONE;
> > > +
> >
> > Is there no constraint at all on the width and height ?
>
> No there are no contraints, at least not listed in the datasheet I have.
>
> > I would expect zero width or height to be invalid for instance, and
> > the width to be required to be a multiple of 2 for YUV 4:2:2 formats.
>
> You just specify the wordcnt in bytes per line. The datasheet I have on
> my side don't say that it is forbidden to write zero to it. Regarding
> the alignment, the datasheet says nothing about it too. But sure it can
> be that this will fail. But shouldn't this fail on the sensor first?
That's a good point. I'm fine without checks here.
> Since this is just a bridge, no-cropping/selection/zoom supported, it
> just takes the input from the parallel interface. If someone
> misconfigured it on purpose the link-validation will fail in case of
> format missmatch. If the format has a wrong alignment, the sensor should
> fail first. But of course I could add a helper to check the alignment
> and to set some sane defaults.
>
> > > + dev_dbg(sd->dev, "Update format: %ux%u code:0x%x -> %ux%u code:0x%x",
> > > + sink_fmt->width, sink_fmt->height, sink_fmt->code,
> > > + format->format.width, format->format.height, format->format.code);
> > > +
> > > + *sink_fmt = format->format;
> > > +
> > > + src_fmt = v4l2_subdev_get_pad_format(sd, sd_state, TC358746_SOURCE);
> > > + *src_fmt = *sink_fmt;
> > > + src_fmt->code = tc358746_src_mbus_code(sink_fmt->code);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static unsigned long tc358746_find_pll_settings(struct tc358746 *tc358746,
> > > + unsigned long refclk,
> > > + unsigned long fout)
> > > +
> > > +{
> > > + struct device *dev = tc358746->sd.dev;
> > > + unsigned long best_freq = 0;
> > > + u32 min_delta = 0xffffffff;
> > > + u16 prediv_max = 17;
> > > + u16 prediv_min = 1;
> > > + u16 m_best, mul;
> > > + u16 p_best, p;
> > > + u8 postdiv;
> > > +
> > > + if (fout > 1000 * MHZ) {
> > > + dev_err(dev, "HS-Clock above 1 Ghz are not supported\n");
> > > + return 0;
> > > + } else if (fout >= 500 * MHZ)
> >
> > If one branch of an if uses curly braces, all should. You can work
> > around this by turning this else if into an if.
>
> Okay.
>
> > > + postdiv = 1;
> > > + else if (fout >= 250 * MHZ)
> > > + postdiv = 2;
> > > + else if (fout >= 125 * MHZ)
> > > + postdiv = 4;
> > > + else
> > > + postdiv = 8;
> > > +
> > > + for (p = prediv_min; p <= prediv_max; p++) {
> > > + unsigned long delta, fin;
> > > + u64 tmp;
> > > +
> > > + fin = DIV_ROUND_CLOSEST(refclk, p);
> > > + if (fin < 4 * MHZ || fin > 40 * MHZ)
> > > + continue;
> > > +
> > > + tmp = fout * p * postdiv;
> > > + do_div(tmp, fin);
> > > + mul = tmp;
> > > + if (mul > 511)
> > > + continue;
> > > +
> > > + tmp = mul * fin;
> > > + do_div(tmp, p * postdiv);
> > > +
> > > + delta = abs(fout - tmp);
> > > + if (delta < min_delta) {
> > > + p_best = p;
> > > + m_best = mul;
> > > + min_delta = delta;
> > > + best_freq = tmp;
> > > + };
> > > +
> > > + if (delta == 0)
> > > + break;
> > > + };
> > > +
> > > + if (!best_freq) {
> > > + dev_err(dev, "Failed find PLL frequency\n");
> > > + return 0;
> > > + }
> > > +
> > > + tc358746->pll_post_div = postdiv;
> > > + tc358746->pll_pre_div = p_best;
> > > + tc358746->pll_mul = m_best;
> > > +
> > > + if (best_freq != fout)
> > > + dev_warn(dev, "Request PLL freq:%lu, found PLL freq:%lu\n",
> > > + fout, best_freq);
> > > +
> > > + dev_dbg(dev, "Found PLL settings: freq:%lu prediv:%u multi:%u postdiv:%u\n",
> > > + best_freq, p_best, m_best, postdiv);
> > > +
> > > + return best_freq;
> > > +}
> > > +
> > > +#define TC358746_PRECISION 10
> > > +
> > > +static int
> > > +tc358746_link_validate(struct v4l2_subdev *sd, struct media_link *link,
> > > + struct v4l2_subdev_format *source_fmt,
> > > + struct v4l2_subdev_format *sink_fmt)
> > > +{
> > > + struct tc358746 *tc358746 = to_tc358746(sd);
> > > + unsigned long csi_bitrate, sensor_bitrate;
> > > + struct v4l2_subdev_state *sink_state;
> > > + struct v4l2_mbus_framefmt *mbusfmt;
> > > + const struct tc358746_format *fmt;
> > > + unsigned int fifo_sz, tmp, n;
> > > + struct v4l2_subdev *sensor;
> > > + s64 sensor_pclk_rate;
> > > + int err;
> > > +
> > > + err = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
> > > + if (err)
> > > + return err;
> > > +
> > > + sink_state = v4l2_subdev_lock_and_get_active_state(sd);
> >
> > This makes me thinkg we should pass the state to this function. Not
> > something that needs to be addressed in this patch of course.
>
> Passing the state? My understanding of *_get_active_state() is to get
> the active state or do you want to add a new function like
> *_get_state(active)?
I meant passing the state to the .link_validate() handler.
> > > + mbusfmt = v4l2_subdev_get_pad_format(sd, sink_state, TC358746_SINK);
> > > + v4l2_subdev_unlock_state(sink_state);
> >
> > I'd release the lock at the end of the function, to make sure the format
> > won't change during validation. This is also a race condition in the
> > subdev core and should be fixed there, I'd be fine if you ignored it
> > here for now.
>
> I can change this but for my understanding. Why is it even possible to
> change the state that late? We are going to enable the stream real
> soon after the validation is done.
Due to bugs in the framework :-) I plan to address that by locking all
states when constructing the pipelines, which will remove the need to
lock them in individual drivers.
> > > +
> > > + /* Check the FIFO settings */
> > > + fmt = tc358746_get_format_by_code(TC358746_SINK, mbusfmt->code);
> > > + if (IS_ERR(fmt))
> > > + return PTR_ERR(fmt);
> >
> > Can this happen if the format has been validate at set_fmt time ?
>
> Of course not, I will drop the IS_ERR().
>
> > > +
> > > + sensor = media_entity_to_v4l2_subdev(link->source->entity);
> > > + sensor_pclk_rate = v4l2_get_link_freq(sensor->ctrl_handler, 0, 0);
> >
> > Shouldn't you set the last two arguments to non-zero values, to support
> > sources that only implement the V4L2_CID_PIXEL_RATE control ?
>
> Nope, I don't wanna support PIXEL_RATE right now. This can be changed
> later I think.
Would it be hard to support it already, given that the
v4l2_get_link_freq() should make it easier ? That would avoid having to
come back to this code later.
> > I'd also name the variable source_link_freq, as it may not be a sensor,
> > and it's a link frequency, not a pixel clock rate.
>
> In parallel case (which is the only supported right now) the pclk is the
> link_freq. but I can change it of course.
I read "pclk" as "pixel clock". That makes me think of
V4L2_CID_PIXEL_RATE, which indicates the number of pixels per second.
With YUV 4:2:2 2X8 media bus formats, the link frequency will be twice
the pixel rate.
> > > + if (sensor_pclk_rate <= 0) {
> > > + dev_err(tc358746->sd.dev,
> > > + "Failed to query or invalid sensor link frequency\n");
> > > + /* Return -EINVAL in case of sensor_pclk_rate is 0 */
> > > + return sensor_pclk_rate ? : -EINVAL;
> > > + }
> > > + sensor_bitrate = sensor_pclk_rate * fmt->bus_width;
> > > +
> > > + csi_bitrate = tc358746->dphy_cfg.lanes * tc358746->pll_rate;
> > > +
> > > + dev_dbg(tc358746->sd.dev,
> > > + "Fifo settings params: sensor-bitrate:%lu csi-bitrate:%lu",
> > > + sensor_bitrate, csi_bitrate);
> > > +
> > > + /* Avoid possible FIFO overflows */
> > > + if (csi_bitrate < sensor_bitrate) {
> > > + dev_err(sd->dev,
> > > + "Link validation failed csi-bitrate:%lu < sensor-bitrate:%lu\n",
> > > + csi_bitrate, sensor_bitrate);
> >
> > As this can be triggered by userspace, I'd make it a dev_dbg().
>
> So you would rather fail silently without printing the reason? Is there
> a common kernel agreement when to use dev_err() or info() or dbg()?
It's not completely silent :-) The idea is that an error condition that
can be triggered by unpriviledged userspace shouldn't be able to flood
the kernel log. dev_dbg() will still allow debugging.
> > > + return -EINVAL;
> > > + }
> > > +
> > > + /* Best case */
> > > + if (csi_bitrate == sensor_bitrate) {
> > > + tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > > + goto out;
> > > + }
> > > +
> > > + /*
> > > + * Avoid possible FIFO underflow in case of
> > > + * csi_bitrate > sensor_bitrate. For such case the chip has a internal
> > > + * fifo which can be used to delay the line output.
> > > + *
> > > + * Fifo size calculation:
> > > + *
> > > + * fifo-sz, image-width - in bits
> > > + * sbr - sensor_bitrate in bits/s
> > > + * csir - csi_bitrate in bits/s
> > > + *
> > > + * 1 1 1
> > > + * image-width * --- + fifo-sz --- >= ---- * image-width
> > > + * sbr sbr csir
> >
> > Given that csir > sbr, 1/csir < 1 sbr, so this will always be true,
> > even with fifo-sz set to 0. Am I missing something ?
>
> Nope, that is right. Didn't checked that while I was coding it.
>
> > > + *
> > > + * fifo-sz >= abs(sbr/csir * image-width - image-width)
> > > + * `-----´
> > > + * n
> >
> > The n variable doesn't store sbr/csir but csir/sbr (multiplied by a
> > precision factor). And do I understand correctly that, as sbr < csir,
> > this would be equal to the following ?
> >
> > * fifo-sz >= image-width - sbr/csir * image-width
>
> Exactly, my above comment and the below code is a bit of, you're right
> but the calc is still correct:
>
> (mbusfmt->width * precision) (mbusfmt->width * precision)
> tmp = ---------------------------- = ----------------------------
> n csi_bitrate
> --------------
> sensor_bitrate
>
> `---------------------------´
> sbr/csir * image-width
>
> maybe I should comment it like:
>
> > * fifo-sz >= abs(sbr/csir * image-width - image-width)
> > *
> > * with n = 1/(sbr/csir) = csir/sbr
> > *
> > * fifo-sz >= abs(image-width / n - image-width)
> > *
> > * or
> > *
> > * fifo-sz >= image-width - image-width / n
>
> > > + *
> > > + */
> > > +
> > > + sensor_bitrate /= TC358746_PRECISION;
> > > + n = csi_bitrate / sensor_bitrate;
> > > + tmp = (mbusfmt->width * TC358746_PRECISION) / n;
> > > + fifo_sz = mbusfmt->width - tmp;
> > > + fifo_sz *= fmt->bpp;
> > > + tc358746->vb_size = round_up(fifo_sz, 32);
> > > +
> > > +out:
> > > + dev_dbg(tc358746->sd.dev,
> > > + "Found FIFO size[bits]:%u -> aligned to size[bits]:%u\n",
> > > + fifo_sz, tc358746->vb_size);
> > > +
> > > + return tc358746->vb_size > TC358746_VB_MAX_SIZE ? -EINVAL : 0;
> > > +}
> > > +
> > > +static int tc358746_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad,
> > > + struct v4l2_mbus_config *config)
> > > +{
> > > + struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > + if (pad != TC358746_SOURCE)
> > > + return -EINVAL;
> > > +
> > > + config->type = V4L2_MBUS_CSI2_DPHY;
> > > + config->bus.mipi_csi2 = tc358746->csi_vep.bus.mipi_csi2;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +int __maybe_unused
> >
> > As reported by the buildbot, this should be static. Same for s_register.
>
> Yes.
>
> > > +tc358746_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
> > > +{
> > > + struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > + /* 32-bit registers starting from CLW_DPHYCONTTX */
> > > + reg->size = reg->reg < CLW_DPHYCONTTX_REG ? 2 : 4;
> > > +
> > > + if (pm_runtime_resume_and_get(sd->dev)) {
> > > + dev_err(sd->dev, "Failed to resume the device\n");
> > > + return 0;
> > > + }
> >
> > Is there a point in powering the hardware on here if it's off, in order
> > to read a register that will have been reset due to the power cycle ?
> > pm_runtime_get_if_in_use() seems better. Same in .s_register().
>
> You're right, I will change that.
>
> > > + tc358746_read(tc358746, reg->reg, (u32 *)®->val);
> > > +
> > > + pm_runtime_mark_last_busy(sd->dev);
> > > + pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +int __maybe_unused
> > > +tc358746_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
> > > +{
> > > + struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > + if (pm_runtime_resume_and_get(sd->dev)) {
> > > + dev_err(sd->dev, "Failed to resume the device\n");
> > > + return 0;
> > > + }
> > > +
> > > + tc358746_write(tc358746, (u32)reg->reg, (u32)reg->val);
> > > +
> > > + pm_runtime_mark_last_busy(sd->dev);
> > > + pm_runtime_put_sync_autosuspend(sd->dev);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static const struct v4l2_subdev_core_ops tc358746_core_ops = {
> > > +#ifdef CONFIG_VIDEO_ADV_DEBUG
> > > + .g_register = tc358746_g_register,
> > > + .s_register = tc358746_s_register,
> > > +#endif
> > > +};
> > > +
> > > +static const struct v4l2_subdev_video_ops tc358746_video_ops = {
> > > + .s_stream = tc358746_s_stream,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_pad_ops tc358746_pad_ops = {
> > > + .init_cfg = tc358746_init_cfg,
> > > + .enum_mbus_code = tc358746_enum_mbus_code,
> > > + .set_fmt = tc358746_set_fmt,
> > > + .get_fmt = v4l2_subdev_get_fmt,
> > > + .link_validate = tc358746_link_validate,
> > > + .get_mbus_config = tc358746_get_mbus_config,
> > > +};
> > > +
> > > +static const struct v4l2_subdev_ops tc358746_ops = {
> > > + .core = &tc358746_core_ops,
> > > + .video = &tc358746_video_ops,
> > > + .pad = &tc358746_pad_ops,
> > > +};
> > > +
> > > +static const struct media_entity_operations tc358746_entity_ops = {
> > > + .get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> > > + .link_validate = v4l2_subdev_link_validate,
> > > +};
> > > +
> > > +static int tc358746_mclk_enable(struct clk_hw *hw)
> > > +{
> > > + struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > + unsigned int div;
> > > + u32 val;
> > > + int err;
> > > +
> > > + div = tc358746->mclk_postdiv / 2;
> > > + val = MCLK_HIGH(div - 1) | MCLK_LOW(div - 1);
> > > + dev_dbg(tc358746->sd.dev, "MCLKCTL: %u (0x%x)\n", val, val);
> > > + err = tc358746_write(tc358746, MCLKCTL_REG, val);
> > > + if (err)
> > > + return err;
> > > +
> > > + if (tc358746->mclk_prediv == 8)
> > > + val = MCLKDIV(MCLKDIV_8);
> > > + else if (tc358746->mclk_prediv == 4)
> > > + val = MCLKDIV(MCLKDIV_4);
> > > + else
> > > + val = MCLKDIV(MCLKDIV_2);
> > > +
> > > + dev_dbg(tc358746->sd.dev, "CLKCTL[MCLKDIV]: %u (0x%x)\n", val, val);
> > > + return tc358746_update_bits(tc358746, CLKCTL_REG, MCLKDIV_MASK, val);
> > > +}
> > > +
> > > +static void tc358746_mclk_disable(struct clk_hw *hw)
> > > +{
> > > + struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > + tc358746_write(tc358746, MCLKCTL_REG, 0);
> > > +}
> > > +
> > > +static long
> > > +tc358746_find_mclk_settings(struct tc358746 *tc358746, unsigned long mclk_rate)
> > > +{
> > > + unsigned long pll_rate = tc358746->pll_rate;
> > > + const unsigned char prediv[] = { 2, 4, 8 };
> > > + unsigned int mclk_prediv, mclk_postdiv;
> > > + struct device *dev = tc358746->sd.dev;
> > > + unsigned int postdiv, mclkdiv;
> > > + unsigned long best_mclk_rate;
> > > + unsigned int i;
> > > +
> > > + /*
> > > + * MCLK-Div
> > > + * -------------------´`---------------------
> > > + * ´ `
> > > + * +-------------+ +------------------------+
> > > + * | MCLK-PreDiv | | MCLK-PostDiv |
> > > + * PLL --> | (2/4/8) | --> | (mclk_low + mclk_high) | --> MCLK
> > > + * +-------------+ +------------------------+
> > > + *
> > > + * The register value of mclk_low/high is mclk_low/high+1, i.e.:
> > > + * mclk_low/high = 1 --> 2 MCLK-Ref Counts
> > > + * mclk_low/high = 255 --> 256 MCLK-Ref Counts == max.
> > > + * If mclk_low and mclk_high are 0 then MCLK is disabled.
> > > + *
> > > + * Keep it simple and support 50/50 duty cycles only for now,
> > > + * so the calc will be:
> > > + *
> > > + * MCLK = PLL / (MCLK-PreDiv * 2 * MCLK-PostDiv)
> > > + */
> > > +
> > > + if (mclk_rate == tc358746->mclk_rate)
> > > + return mclk_rate;
> > > +
> > > + /* Highest possible rate */
> > > + mclkdiv = pll_rate / mclk_rate;
> > > + if (mclkdiv <= 8) {
> > > + mclk_prediv = 2;
> > > + mclk_postdiv = 4;
> > > + best_mclk_rate = pll_rate / (2 * 4);
> > > + goto out;
> > > + }
> > > +
> > > + /* First check the prediv */
> > > + for (i = 0; i < ARRAY_SIZE(prediv); i++) {
> > > + postdiv = mclkdiv / prediv[i];
> > > +
> > > + if (postdiv % 2)
> > > + continue;
> > > +
> > > + if (postdiv >= 4 && postdiv <= 512) {
> > > + mclk_prediv = prediv[i];
> > > + mclk_postdiv = postdiv;
> > > + best_mclk_rate = pll_rate / (prediv[i] * postdiv);
> > > + goto out;
> > > + }
> > > + }
> > > +
> > > + /* No suitable prediv found, so try to adjust the postdiv */
> > > + for (postdiv = 4; postdiv <= 512; postdiv += 2) {
> > > + unsigned int pre;
> > > +
> > > + pre = mclkdiv / postdiv;
> > > + if (pre == 2 || pre == 4 || pre == 8) {
> > > + mclk_prediv = pre;
> > > + mclk_postdiv = postdiv;
> > > + best_mclk_rate = pll_rate / (pre * postdiv);
> > > + goto out;
> > > + }
> > > + }
> > > +
> > > + /* The MCLK <-> PLL gap is to high -> use largest possible div */
> > > + mclk_prediv = 8;
> > > + mclk_postdiv = 512;
> > > + best_mclk_rate = pll_rate / (8 * 512);
> > > +
> > > +out:
> > > + tc358746->mclk_prediv = mclk_prediv;
> > > + tc358746->mclk_postdiv = mclk_postdiv;
> > > + tc358746->mclk_rate = best_mclk_rate;
> > > +
> > > + if (best_mclk_rate != mclk_rate)
> > > + dev_warn(dev, "Request MCLK freq:%lu, found MCLK freq:%lu\n",
> > > + mclk_rate, best_mclk_rate);
> > > +
> > > + dev_dbg(dev, "Found MCLK settings: freq:%lu prediv:%u postdiv:%u\n",
> > > + best_mclk_rate, mclk_prediv, mclk_postdiv);
> > > +
> > > + return best_mclk_rate;
> > > +}
> > > +
> > > +unsigned long tc358746_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> > > +{
> > > + struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > + unsigned int prediv, postdiv;
> > > + u32 val;
> > > + int err;
> > > +
> > > + err = tc358746_read(tc358746, MCLKCTL_REG, &val);
> > > + if (err)
> > > + return 0;
> > > +
> > > + postdiv = FIELD_GET(MCLK_LOW_MASK, val) + 1;
> > > + postdiv += FIELD_GET(MCLK_HIGH_MASK, val) + 1;
> > > +
> > > + err = tc358746_read(tc358746, CLKCTL_REG, &val);
> > > + if (err)
> > > + return 0;
> > > +
> > > + prediv = FIELD_GET(MCLKDIV_MASK, val);
> > > + if (prediv == MCLKDIV_8)
> > > + prediv = 8;
> > > + else if (prediv == MCLKDIV_4)
> > > + prediv = 4;
> > > + else
> > > + prediv = 2;
> > > +
> > > + return tc358746->pll_rate / (prediv * postdiv);
> > > +}
> > > +
> > > +static long tc358746_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
> > > + unsigned long *parent_rate)
> > > +{
> > > + struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > + *parent_rate = tc358746->pll_rate;
> > > +
> > > + return tc358746_find_mclk_settings(tc358746, rate);
> > > +}
> > > +
> > > +static int tc358746_mclk_set_rate(struct clk_hw *hw, unsigned long rate,
> > > + unsigned long parent_rate)
> > > +{
> > > + struct tc358746 *tc358746 = clk_hw_to_tc358746(hw);
> > > +
> > > + tc358746_find_mclk_settings(tc358746, rate);
> > > +
> > > + return tc358746_mclk_enable(hw);
> > > +}
> > > +
> > > +static const struct clk_ops tc358746_mclk_ops = {
> > > + .enable = tc358746_mclk_enable,
> > > + .disable = tc358746_mclk_disable,
> > > + .recalc_rate = tc358746_recalc_rate,
> > > + .round_rate = tc358746_mclk_round_rate,
> > > + .set_rate = tc358746_mclk_set_rate,
> > > +};
> > > +
> > > +static int
> > > +tc358746_init_subdev(struct tc358746 *tc358746, struct i2c_client *client)
> > > +{
> > > + struct v4l2_subdev *sd;
> > > + int err;
> > > +
> > > + sd = &tc358746->sd;
> >
> > You could initialize the variable when declaring it.
>
> Yes.
>
> > > + v4l2_i2c_subdev_init(sd, client, &tc358746_ops);
> > > + sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > > + sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> > > + sd->entity.ops = &tc358746_entity_ops;
> > > +
> > > + tc358746->pads[TC358746_SINK].flags = MEDIA_PAD_FL_SINK;
> > > + tc358746->pads[TC358746_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > > + err = media_entity_pads_init(&sd->entity, TC358746_NR_PADS,
> > > + tc358746->pads);
> > > + if (err)
> > > + return err;
> > > +
> > > + err = v4l2_subdev_init_finalize(sd);
> > > + if (err)
> > > + media_entity_cleanup(&sd->entity);
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static int
> > > +tc358746_init_output_port(struct tc358746 *tc358746, unsigned long refclk)
> > > +{
> > > + struct device *dev = tc358746->sd.dev;
> > > + struct v4l2_fwnode_endpoint *vep;
> > > + unsigned long csi_link_rate;
> > > + struct fwnode_handle *ep;
> > > + unsigned char csi_lanes;
> > > + int err;
> > > +
> > > + ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), TC358746_SOURCE,
> > > + 0, 0);
> > > + if (!ep) {
> > > + dev_err(dev, "Missing endpoint node\n");
> > > + return -EINVAL;
> > > + }
> > > +
> > > + /* Currently we only support 'parallel in' -> 'csi out' */
> > > + vep = &tc358746->csi_vep;
> > > + vep->bus_type = V4L2_MBUS_CSI2_DPHY;
> > > + err = v4l2_fwnode_endpoint_alloc_parse(ep, vep);
> > > + fwnode_handle_put(ep);
> > > + if (err) {
> > > + dev_err(dev, "Failed to parse source endpoint\n");
> > > + return err;
> > > + }
> > > +
> > > + csi_lanes = vep->bus.mipi_csi2.num_data_lanes;
> > > + if (csi_lanes == 0 || csi_lanes > 4 ||
> > > + vep->nr_of_link_frequencies == 0) {
> > > + dev_err(dev, "error: Invalid CSI-2 settings\n");
> > > + err = -EINVAL;
> > > + goto err;
> > > + }
> > > +
> > > + /* TODO: Add support to handle multiple link frequencies */
> > > + csi_link_rate = (unsigned long)vep->link_frequencies[0];
> > > + tc358746->pll_rate = tc358746_find_pll_settings(tc358746, refclk,
> > > + csi_link_rate * 2);
> > > + if (!tc358746->pll_rate) {
> > > + err = -EINVAL;
> > > + goto err;
> > > + }
> > > +
> > > + err = phy_mipi_dphy_get_default_config_for_hsclk(tc358746->pll_rate,
> > > + csi_lanes, &tc358746->dphy_cfg);
> > > + if (err)
> > > + goto err;
> > > +
> > > + tc358746->vb_size = TC358746_VB_DEFAULT_SIZE;
> > > +
> > > + return 0;
> > > +
> > > +err:
> > > + v4l2_fwnode_endpoint_free(vep);
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static int tc358746_init_hw(struct tc358746 *tc358746)
> > > +{
> > > + struct device *dev = tc358746->sd.dev;
> > > + unsigned int chipid;
> > > + u32 val;
> > > + int err;
> > > +
> > > + err = pm_runtime_resume_and_get(dev);
> > > + if (err < 0) {
> > > + dev_err(dev, "Failed to resume the device\n");
> > > + return err;
> > > + }
> > > +
> > > + /* Ensure that CSI interface is put into LP-11 state */
> > > + err = tc358746_sw_reset(tc358746);
> > > + if (err) {
> > > + pm_runtime_put_noidle(dev);
> >
> > Don't you need a regular put (possibly with autosuspend) here ?
> > Otherwise a reset failure will decrement the runtime PM use count but
> > leave the decide powered.
>
> The runtime_disable() will be called within the probe(). Please see
> the error path there for tc358746_init_hw().
Those are two different things, I don't think pm_runtime_disable() will
power the device off.
> > > + dev_err(dev, "Failed to reset the device\n");
> > > + return err;
> > > + }
> > > +
> > > + err = tc358746_read(tc358746, CHIPID_REG, &val);
> > > + pm_runtime_mark_last_busy(dev);
> > > + pm_runtime_put_sync_autosuspend(dev);
> > > + if (err) {
> > > + dev_err(dev, "Failed to read chipid\n");
> >
> > How about moving the read failure message to tc358746_read() ? It's
> > useful to get error messages for all failures, not just this one. Or do
> > we get a message from regmap already ? If we do, then we could just drop
> > this.
>
> I don't see any code within regmap. I will move it to tc358746_read()
> and tc358746_write() helpers.
>
> > > + return -ENODEV;
> > > + }
> > > +
> > > + chipid = FIELD_GET(CHIPID, val);
> > > + if (chipid != 0x44) {
> > > + dev_err(dev, "Invalid chipid 0x%02x\n", chipid);
> > > + return -ENODEV;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int tc358746_setup_mclk_provider(struct tc358746 *tc358746)
> >
> > I'd move this right after tc358746_mclk_ops as they're related.
>
> Okay.
>
> > > +{
> > > + struct clk_init_data mclk_initdata = { };
> > > + struct device *dev = tc358746->sd.dev;
> > > + const char *mclk_name;
> > > + int err;
> > > +
> > > + /* MCLK clk provider support is optional */
> > > + if (!device_property_present(dev, "#clock-cells"))
> > > + return 0;
> > > +
> > > + /* Init to highest possibel MCLK */
> > > + tc358746->mclk_postdiv = 512;
> > > + tc358746->mclk_prediv = 8;
> > > +
> > > + mclk_name = "tc358746-mclk";
> > > + device_property_read_string(dev, "clock-output-names",
> > > + &mclk_name);
> >
> > This holds on a single line.
>
> Sure.
>
> > > +
> > > + mclk_initdata.name = mclk_name;
> > > + mclk_initdata.ops = &tc358746_mclk_ops;
> > > + tc358746->mclk_hw.init = &mclk_initdata;
> > > +
> > > + err = devm_clk_hw_register(dev, &tc358746->mclk_hw);
> > > + if (err) {
> > > + dev_err(dev, "Failed to register mclk provider\n");
> > > + return err;
> > > + }
> > > +
> > > + err = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
> > > + &tc358746->mclk_hw);
> > > + if (err)
> > > + dev_err(dev, "Failed to add mclk provider\n");
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static int tc358746_init_controls(struct tc358746 *tc358746)
> > > +{
> > > + u64 *link_frequencies = tc358746->csi_vep.link_frequencies;
> > > + struct v4l2_ctrl *ctrl;
> > > + int err;
> > > +
> > > + err = v4l2_ctrl_handler_init(&tc358746->ctrl_hdl, 1);
> > > + if (err)
> > > + return err;
> > > +
> > > + ctrl = v4l2_ctrl_new_int_menu(&tc358746->ctrl_hdl, NULL,
> > > + V4L2_CID_LINK_FREQ, 0, 0,
> >
> > Shouldn't the max argument be set to the number of items minus 1 ?
>
> Right now I would keep it that way since the driver only supports one
> link-frequencies setting. So the ctrl don't let the userspace assume
> that there are more than one link-frequency.
Good point. Can you add a short comment above the call to explain this ?
> > > + link_frequencies);
> > > + if (ctrl)
> > > + ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > > +
> > > + tc358746->sd.ctrl_handler = &tc358746->ctrl_hdl;
> > > + if (tc358746->ctrl_hdl.error)
> > > + return tc358746->ctrl_hdl.error;
> >
> > You need to call v4l2_ctrl_handler_free() in the failure paths.
>
> Arg.. you're right.
>
> > > +
> > > + return v4l2_ctrl_handler_setup(&tc358746->ctrl_hdl);
> >
> > This can be skipped I think, as the only supported control is read-only.
>
> Yes, you're right.
>
> > > +}
> > > +
> > > +static int tc358746_notify_bound(struct v4l2_async_notifier *notifier,
> > > + struct v4l2_subdev *sd,
> > > + struct v4l2_async_subdev *asd)
> > > +{
> > > + struct tc358746 *tc358746 =
> > > + container_of(notifier, struct tc358746, notifier);
> > > + struct media_pad *sink = &tc358746->pads[TC358746_SINK];
> > > +
> > > + return v4l2_create_fwnode_links_to_pad(sd, sink, MEDIA_LNK_FL_ENABLED);
> >
> > I'd make the link immutable too, as only one source subdev is supported.
>
> Yes, I can do that.
>
> > > +}
> > > +
> > > +static const struct v4l2_async_notifier_operations tc358746_notify_ops = {
> > > + .bound = tc358746_notify_bound,
> > > +};
> > > +
> > > +static int tc358746_async_register(struct tc358746 *tc358746)
> > > +{
> > > + struct v4l2_fwnode_endpoint vep = {
> > > + .bus_type = V4L2_MBUS_PARALLEL,
> > > + };
> > > + struct v4l2_async_subdev *asd;
> > > + struct fwnode_handle *ep;
> > > + int err;
> > > +
> > > + ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(tc358746->sd.dev),
> > > + TC358746_SINK, 0, 0);
> > > + if (!ep)
> > > + return -ENOTCONN;
> > > +
> > > + err = v4l2_fwnode_endpoint_parse(ep, &vep);
> > > + if (err) {
> > > + fwnode_handle_put(ep);
> > > + return err;
> > > + }
> > > +
> > > + v4l2_async_nf_init(&tc358746->notifier);
> > > + asd = v4l2_async_nf_add_fwnode_remote(&tc358746->notifier, ep,
> > > + struct v4l2_async_subdev);
> > > + if (IS_ERR(asd)) {
> > > + fwnode_handle_put(ep);
> >
> > You can move this before the error check and drop the next one.
>
> Sure, thanks.
>
> > > + return PTR_ERR(asd);
> >
> > Shouldn't v4l2_async_nf_cleanup() be called here ?
>
> Yep.
>
> > > + }
> > > +
> > > + fwnode_handle_put(ep);
> > > +
> > > + tc358746->notifier.ops = &tc358746_notify_ops;
> > > +
> > > + err = v4l2_async_subdev_nf_register(&tc358746->sd, &tc358746->notifier);
> > > + if (err) {
> > > + v4l2_async_nf_cleanup(&tc358746->notifier);
> > > + return err;
> > > + }
> > > +
> > > + tc358746->sd.fwnode = fwnode_graph_get_endpoint_by_id(
> > > + dev_fwnode(tc358746->sd.dev), TC358746_SOURCE, 0, 0);
> >
> > Where is this reference dropped ?
>
> That's a good question, should it be dropped upon the notify callback or
> does the v4l2-subdev use the fwnode elsewhere? I introduced this to get
> rid of the message: "considering updating the driver..".
I think it needs to be dropped in .remove() (and in probe error paths,
as needed).
> > > +
> > > + err = v4l2_async_register_subdev(&tc358746->sd);
> > > + if (err) {
> > > + v4l2_async_nf_unregister(&tc358746->notifier);
> > > + v4l2_async_nf_cleanup(&tc358746->notifier);
> > > + }
> > > +
> > > + return err;
> >
> > return 0;
>
> This would drop possible errors from async_register, but I changed the
> function completely, so I will return 0 :)
I had misread the code, I thought there was a return err in the error
condition, my bad.
> > > +}
> > > +
> > > +static int tc358746_probe(struct i2c_client *client)
> > > +{
> > > + struct device *dev = &client->dev;
> > > + struct tc358746 *tc358746;
> > > + unsigned long refclk;
> > > + unsigned int i;
> > > + int err;
> > > +
> > > + tc358746 = devm_kzalloc(&client->dev, sizeof(*tc358746), GFP_KERNEL);
> > > + if (!tc358746)
> > > + return -ENOMEM;
> > > +
> > > + tc358746->regmap = devm_regmap_init_i2c(client, &tc358746_regmap_config);
> > > + if (IS_ERR(tc358746->regmap))
> > > + return dev_err_probe(dev, PTR_ERR(tc358746->regmap),
> > > + "Failed to init regmap\n");
> > > +
> > > + tc358746->refclk = devm_clk_get(dev, "refclk");
> > > + if (IS_ERR(tc358746->refclk))
> > > + return dev_err_probe(dev, PTR_ERR(tc358746->refclk),
> > > + "Failed to get refclk\n");
> > > +
> > > + err = clk_prepare_enable(tc358746->refclk);
> > > + if (err)
> > > + return dev_err_probe(dev, err,
> > > + "Failed to enable refclk\n");
> > > +
> > > + refclk = clk_get_rate(tc358746->refclk);
> > > + clk_disable_unprepare(tc358746->refclk);
> > > +
> > > + if (refclk < 6 * MHZ || refclk > 40 * MHZ)
> > > + return dev_err_probe(dev, -EINVAL, "Invalid refclk range\n");
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(tc358746_supplies); i++)
> > > + tc358746->supplies[i].supply = tc358746_supplies[i];
> > > +
> > > + err = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc358746_supplies),
> > > + tc358746->supplies);
> > > + if (err)
> > > + return dev_err_probe(dev, err, "Failed to get supplies\n");
> > > +
> > > + tc358746->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > > + GPIOD_OUT_HIGH);
> > > + if (IS_ERR(tc358746->reset_gpio))
> > > + return dev_err_probe(dev, PTR_ERR(tc358746->reset_gpio),
> > > + "Failed to get reset-gpios\n");
> > > +
> > > + err = tc358746_init_subdev(tc358746, client);
> > > + if (err)
> > > + return dev_err_probe(dev, err, "Failed to init subdev\n");
> > > +
> > > + err = tc358746_init_output_port(tc358746, refclk);
> > > + if (err)
> > > + goto err_subdev;
> > > +
> > > + /*
> > > + * Keep this order since we need the output port link-frequencies
> > > + * information.
> > > + */
> > > + err = tc358746_init_controls(tc358746);
> > > + if (err)
> > > + goto err_fwnode;
> > > +
> > > + dev_set_drvdata(dev, tc358746);
> > > + pm_runtime_set_autosuspend_delay(dev, 200);
> >
> > 200ms may be a bit short for a complete stop/restart cycle. How about
> > 1s ?
>
> Isn't it the time upon which the pm-fw will put the device into stop? I
> can increase it of course, but I don't see any improvements for it.
The idea is that autosuspend is helpful to avoid an expensive
power-off/power-on cycle when stopping video capture, reconfiguring the
source (and the pipeline) and restarting capture. Depending on the
source, 200ms may be a bit short.
> Thanks again for the detailed review :)
>
> Regards,
> Marco
>
> > > + pm_runtime_use_autosuspend(dev);
> > > + pm_runtime_enable(dev);
> > > +
> > > + err = tc358746_init_hw(tc358746);
> > > + if (err)
> > > + goto err_pm;
> > > +
> > > + err = tc358746_setup_mclk_provider(tc358746);
> > > + if (err)
> > > + goto err_pm;
> > > +
> > > + err = tc358746_async_register(tc358746);
> > > + if (err < 0)
> > > + goto err_pm;
> > > +
> > > + dev_dbg(dev, "%s found @ 0x%x (%s)\n", client->name,
> > > + client->addr, client->adapter->name);
> > > +
> > > + return 0;
> > > +
> > > +err_pm:
> > > + pm_runtime_disable(dev);
> > > + pm_runtime_set_suspended(dev);
> > > + pm_runtime_dont_use_autosuspend(dev);
> > > + v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > +err_fwnode:
> > > + v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > > +err_subdev:
> > > + v4l2_subdev_cleanup(&tc358746->sd);
> > > + media_entity_cleanup(&tc358746->sd.entity);
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static int tc358746_remove(struct i2c_client *client)
> > > +{
> > > + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > > + struct tc358746 *tc358746 = to_tc358746(sd);
> > > +
> > > + v4l2_subdev_cleanup(sd);
> > > + v4l2_ctrl_handler_free(&tc358746->ctrl_hdl);
> > > + v4l2_fwnode_endpoint_free(&tc358746->csi_vep);
> > > + v4l2_async_nf_unregister(&tc358746->notifier);
> > > + v4l2_async_nf_cleanup(&tc358746->notifier);
> > > + v4l2_async_unregister_subdev(sd);
> > > + media_entity_cleanup(&sd->entity);
> > > +
> > > + pm_runtime_disable(sd->dev);
> > > + pm_runtime_set_suspended(sd->dev);
> > > + pm_runtime_dont_use_autosuspend(sd->dev);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int tc358746_suspend(struct device *dev)
> > > +{
> > > + struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > > + int err;
> > > +
> > > + clk_disable_unprepare(tc358746->refclk);
> > > +
> > > + err = regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > > + tc358746->supplies);
> > > + if (err)
> > > + clk_prepare_enable(tc358746->refclk);
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static int tc358746_resume(struct device *dev)
> > > +{
> > > + struct tc358746 *tc358746 = dev_get_drvdata(dev);
> > > + int err;
> > > +
> > > + gpiod_set_value(tc358746->reset_gpio, 1);
> > > +
> > > + err = regulator_bulk_enable(ARRAY_SIZE(tc358746_supplies),
> > > + tc358746->supplies);
> > > + if (err)
> > > + return err;
> > > +
> > > + /* min. 200ns */
> > > + usleep_range(10, 20);
> > > +
> > > + gpiod_set_value(tc358746->reset_gpio, 0);
> > > +
> > > + err = clk_prepare_enable(tc358746->refclk);
> > > + if (err)
> > > + goto err;
> > > +
> > > + /* min. 700us ... 1ms */
> > > + usleep_range(1000, 1500);
> > > +
> > > + /*
> > > + * Enable the PLL here since it can be called by the clk-framework or by
> > > + * the .s_stream() callback. So this is the common place for both.
> > > + */
> > > + err = tc358746_apply_pll_config(tc358746);
> > > + if (err)
> > > + goto err_clk;
> > > +
> > > + return 0;
> > > +
> > > +err_clk:
> > > + clk_disable_unprepare(tc358746->refclk);
> > > +err:
> > > + regulator_bulk_disable(ARRAY_SIZE(tc358746_supplies),
> > > + tc358746->supplies);
> > > + return err;
> > > +}
> > > +
> > > +DEFINE_RUNTIME_DEV_PM_OPS(tc358746_pm_ops, tc358746_suspend,
> > > + tc358746_resume, NULL);
> > > +
> > > +static const struct of_device_id __maybe_unused tc358746_of_match[] = {
> > > + { .compatible = "toshiba,tc358746" },
> > > + { },
> > > +};
> > > +MODULE_DEVICE_TABLE(of, tc358746_of_match);
> > > +
> > > +static struct i2c_driver tc358746_driver = {
> > > + .driver = {
> > > + .name = "tc358746",
> > > + .pm = pm_ptr(&tc358746_pm_ops),
> > > + .of_match_table = tc358746_of_match,
> > > + },
> > > + .probe_new = tc358746_probe,
> > > + .remove = tc358746_remove,
> > > +};
> > > +
> > > +module_i2c_driver(tc358746_driver);
> > > +
> > > +MODULE_DESCRIPTION("Toshiba TC358746 Parallel to CSI-2 bridge driver");
> > > +MODULE_AUTHOR("Marco Felsch <kernel@xxxxxxxxxxxxxx>");
> > > +MODULE_LICENSE("GPL");
--
Regards,
Laurent Pinchart