// SPDX-License-Identifier: GPL-2.0+ /* * MIPI CSI-2 Receiver Subdev for Freescale i.MX6 SOC. * * Copyright (c) 2012-2017 Mentor Graphics Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include "imx-media.h" /* * there must be 5 pads: 1 input pad from sensor, and * the 4 virtual channel output pads */ #define CSI2_SINK_PAD 0 #define CSI2_NUM_SINK_PADS 1 #define CSI2_NUM_SRC_PADS 4 #define CSI2_NUM_PADS 5 /* * The default maximum bit-rate per lane in Mbps, if the * source subdev does not provide V4L2_CID_LINK_FREQ. */ #define CSI2_DEFAULT_MAX_MBPS 849 struct csi2_dev { struct device *dev; struct v4l2_subdev sd; struct media_pad pad[CSI2_NUM_PADS]; struct clk *dphy_clk; struct clk *pllref_clk; struct clk *pix_clk; /* what is this? */ void __iomem *base; struct v4l2_fwnode_bus_mipi_csi2 bus; /* lock to protect all members below */ struct mutex lock; struct v4l2_mbus_framefmt format_mbus; int stream_count; struct v4l2_subdev *src_sd; bool sink_linked[CSI2_NUM_SRC_PADS]; }; #define DEVICE_NAME "imx6-mipi-csi2" /* Register offsets */ #define CSI2_VERSION 0x000 #define CSI2_N_LANES 0x004 #define CSI2_PHY_SHUTDOWNZ 0x008 #define CSI2_DPHY_RSTZ 0x00c #define CSI2_RESETN 0x010 #define CSI2_PHY_STATE 0x014 #define PHY_STOPSTATEDATA_BIT 4 #define PHY_STOPSTATEDATA(n) BIT(PHY_STOPSTATEDATA_BIT + (n)) #define PHY_RXCLKACTIVEHS BIT(8) #define PHY_RXULPSCLKNOT BIT(9) #define PHY_STOPSTATECLK BIT(10) #define CSI2_DATA_IDS_1 0x018 #define CSI2_DATA_IDS_2 0x01c #define CSI2_ERR1 0x020 #define CSI2_ERR2 0x024 #define CSI2_MSK1 0x028 #define CSI2_MSK2 0x02c #define CSI2_PHY_TST_CTRL0 0x030 #define PHY_TESTCLR BIT(0) #define PHY_TESTCLK BIT(1) #define CSI2_PHY_TST_CTRL1 0x034 #define PHY_TESTEN BIT(16) /* * i.MX CSI2IPU Gasket registers follow. The CSI2IPU gasket is * not part of the MIPI CSI-2 core, but its registers fall in the * same register map range. */ #define CSI2IPU_GASKET 0xf00 #define CSI2IPU_YUV422_YUYV BIT(2) static inline struct csi2_dev *sd_to_dev(struct v4l2_subdev *sdev) { return container_of(sdev, struct csi2_dev, sd); } /* * The required sequence of MIPI CSI-2 startup as specified in the i.MX6 * reference manual is as follows: * * 1. Deassert presetn signal (global reset). * It's not clear what this "global reset" signal is (maybe APB * global reset), but in any case this step would be probably * be carried out during driver load in csi2_probe(). * * 2. Configure MIPI Camera Sensor to put all Tx lanes in LP-11 state. * This must be carried out by the MIPI sensor's s_power(ON) subdev * op. * * 3. D-PHY initialization. * 4. CSI2 Controller programming (Set N_LANES, deassert PHY_SHUTDOWNZ, * deassert PHY_RSTZ, deassert CSI2_RESETN). * 5. Read the PHY status register (PHY_STATE) to confirm that all data and * clock lanes of the D-PHY are in LP-11 state. * 6. Configure the MIPI Camera Sensor to start transmitting a clock on the * D-PHY clock lane. * 7. CSI2 Controller programming - Read the PHY status register (PHY_STATE) * to confirm that the D-PHY is receiving a clock on the D-PHY clock lane. * * All steps 3 through 7 are carried out by csi2_s_stream(ON) here. Step * 6 is accomplished by calling the source subdev's s_stream(ON) between * steps 5 and 7. */ static void csi2_enable(struct csi2_dev *csi2, bool enable) { if (enable) { writel(0x1, csi2->base + CSI2_PHY_SHUTDOWNZ); writel(0x1, csi2->base + CSI2_DPHY_RSTZ); writel(0x1, csi2->base + CSI2_RESETN); } else { writel(0x0, csi2->base + CSI2_PHY_SHUTDOWNZ); writel(0x0, csi2->base + CSI2_DPHY_RSTZ); writel(0x0, csi2->base + CSI2_RESETN); } } static void csi2_set_lanes(struct csi2_dev *csi2) { int lanes = csi2->bus.num_data_lanes; writel(lanes - 1, csi2->base + CSI2_N_LANES); } static void dw_mipi_csi2_phy_write(struct csi2_dev *csi2, u32 test_code, u32 test_data) { /* Clear PHY test interface */ writel(PHY_TESTCLR, csi2->base + CSI2_PHY_TST_CTRL0); writel(0x0, csi2->base + CSI2_PHY_TST_CTRL1); writel(0x0, csi2->base + CSI2_PHY_TST_CTRL0); /* Raise test interface strobe signal */ writel(PHY_TESTCLK, csi2->base + CSI2_PHY_TST_CTRL0); /* Configure address write on falling edge and lower strobe signal */ writel(PHY_TESTEN | test_code, csi2->base + CSI2_PHY_TST_CTRL1); writel(0x0, csi2->base + CSI2_PHY_TST_CTRL0); /* Configure data write on rising edge and raise strobe signal */ writel(test_data, csi2->base + CSI2_PHY_TST_CTRL1); writel(PHY_TESTCLK, csi2->base + CSI2_PHY_TST_CTRL0); /* Clear strobe signal */ writel(0x0, csi2->base + CSI2_PHY_TST_CTRL0); } /* * This table is based on the table documented at * https://community.nxp.com/docs/DOC-94312. It assumes * a 27MHz D-PHY pll reference clock. */ static const struct { u32 max_mbps; u32 hsfreqrange_sel; } hsfreq_map[] = { { 90, 0x00}, {100, 0x20}, {110, 0x40}, {125, 0x02}, {140, 0x22}, {150, 0x42}, {160, 0x04}, {180, 0x24}, {200, 0x44}, {210, 0x06}, {240, 0x26}, {250, 0x46}, {270, 0x08}, {300, 0x28}, {330, 0x48}, {360, 0x2a}, {400, 0x4a}, {450, 0x0c}, {500, 0x2c}, {550, 0x0e}, {600, 0x2e}, {650, 0x10}, {700, 0x30}, {750, 0x12}, {800, 0x32}, {850, 0x14}, {900, 0x34}, {950, 0x54}, {1000, 0x74}, }; static int max_mbps_to_hsfreqrange_sel(u32 max_mbps) { int i; for (i = 0; i < ARRAY_SIZE(hsfreq_map); i++) if (hsfreq_map[i].max_mbps > max_mbps) return hsfreq_map[i].hsfreqrange_sel; return -EINVAL; } static int csi2_dphy_init(struct csi2_dev *csi2) { struct v4l2_ctrl *ctrl; u32 mbps_per_lane; int sel; ctrl = v4l2_ctrl_find(csi2->src_sd->ctrl_handler, V4L2_CID_LINK_FREQ); if (!ctrl) mbps_per_lane = CSI2_DEFAULT_MAX_MBPS; else mbps_per_lane = DIV_ROUND_UP_ULL(2 * ctrl->qmenu_int[ctrl->val], USEC_PER_SEC); sel = max_mbps_to_hsfreqrange_sel(mbps_per_lane); if (sel < 0) return sel; dw_mipi_csi2_phy_write(csi2, 0x44, sel); return 0; } /* * Waits for ultra-low-power state on D-PHY clock lane. This is currently * unused and may not be needed at all, but keep around just in case. */ static int __maybe_unused csi2_dphy_wait_ulp(struct csi2_dev *csi2) { u32 reg; int ret; /* wait for ULP on clock lane */ ret = readl_poll_timeout(csi2->base + CSI2_PHY_STATE, reg, !(reg & PHY_RXULPSCLKNOT), 0, 500000); if (ret) { v4l2_err(&csi2->sd, "ULP timeout, phy_state = 0x%08x\n", reg); return ret; } /* wait until no errors on bus */ ret = readl_poll_timeout(csi2->base + CSI2_ERR1, reg, reg == 0x0, 0, 500000); if (ret) { v4l2_err(&csi2->sd, "stable bus timeout, err1 = 0x%08x\n", reg); return ret; } return 0; } /* Waits for low-power LP-11 state on data and clock lanes. */ static int csi2_dphy_wait_stopstate(struct csi2_dev *csi2) { u32 mask, reg; int ret; mask = PHY_STOPSTATECLK | (((1 << csi2->bus.num_data_lanes) - 1) << PHY_STOPSTATEDATA_BIT); ret = readl_poll_timeout(csi2->base + CSI2_PHY_STATE, reg, (reg & mask) == mask, 0, 500000); if (ret) { v4l2_err(&csi2->sd, "LP-11 timeout, phy_state = 0x%08x\n", reg); return ret; } return 0; } /* Wait for active clock on the clock lane. */ static int csi2_dphy_wait_clock_lane(struct csi2_dev *csi2) { u32 reg; int ret; ret = readl_poll_timeout(csi2->base + CSI2_PHY_STATE, reg, (reg & PHY_RXCLKACTIVEHS), 0, 500000); if (ret) { v4l2_err(&csi2->sd, "clock lane timeout, phy_state = 0x%08x\n", reg); return ret; } return 0; } /* Setup the i.MX CSI2IPU Gasket */ static void csi2ipu_gasket_init(struct csi2_dev *csi2) { u32 reg = 0; switch (csi2->format_mbus.code) { case MEDIA_BUS_FMT_YUYV8_2X8: case MEDIA_BUS_FMT_YUYV8_1X16: reg = CSI2IPU_YUV422_YUYV; break; default: break; } writel(reg, csi2->base + CSI2IPU_GASKET); } static int csi2_start(struct csi2_dev *csi2) { int ret; ret = clk_prepare_enable(csi2->pix_clk); if (ret) return ret; /* setup the gasket */ csi2ipu_gasket_init(csi2); /* Step 3 */ ret = csi2_dphy_init(csi2); if (ret) goto err_disable_clk; /* Step 4 */ csi2_set_lanes(csi2); csi2_enable(csi2, true); /* Step 5 */ ret = csi2_dphy_wait_stopstate(csi2); if (ret) goto err_assert_reset; /* Step 6 */ ret = v4l2_subdev_call(csi2->src_sd, video, s_stream, 1); ret = (ret && ret != -ENOIOCTLCMD) ? ret : 0; if (ret) goto err_assert_reset; /* Step 7 */ ret = csi2_dphy_wait_clock_lane(csi2); if (ret) goto err_stop_upstream; return 0; err_stop_upstream: v4l2_subdev_call(csi2->src_sd, video, s_stream, 0); err_assert_reset: csi2_enable(csi2, false); err_disable_clk: clk_disable_unprepare(csi2->pix_clk); return ret; } static void csi2_stop(struct csi2_dev *csi2) { /* stop upstream */ v4l2_subdev_call(csi2->src_sd, video, s_stream, 0); csi2_enable(csi2, false); clk_disable_unprepare(csi2->pix_clk); } /* * V4L2 subdev operations. */ static int csi2_s_stream(struct v4l2_subdev *sd, int enable) { struct csi2_dev *csi2 = sd_to_dev(sd); int i, ret = 0; mutex_lock(&csi2->lock); if (!csi2->src_sd) { ret = -EPIPE; goto out; } for (i = 0; i < CSI2_NUM_SRC_PADS; i++) { if (csi2->sink_linked[i]) break; } if (i >= CSI2_NUM_SRC_PADS) { ret = -EPIPE; goto out; } /* * enable/disable streaming only if stream_count is * going from 0 to 1 / 1 to 0. */ if (csi2->stream_count != !enable) goto update_count; dev_dbg(csi2->dev, "stream %s\n", enable ? "ON" : "OFF"); if (enable) ret = csi2_start(csi2); else csi2_stop(csi2); if (ret) goto out; update_count: csi2->stream_count += enable ? 1 : -1; if (csi2->stream_count < 0) csi2->stream_count = 0; out: mutex_unlock(&csi2->lock); return ret; } static int csi2_link_setup(struct media_entity *entity, const struct media_pad *local, const struct media_pad *remote, u32 flags) { struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity); struct csi2_dev *csi2 = sd_to_dev(sd); struct v4l2_subdev *remote_sd; int ret = 0; dev_dbg(csi2->dev, "link setup %s -> %s", remote->entity->name, local->entity->name); remote_sd = media_entity_to_v4l2_subdev(remote->entity); mutex_lock(&csi2->lock); if (local->flags & MEDIA_PAD_FL_SOURCE) { if (flags & MEDIA_LNK_FL_ENABLED) { if (csi2->sink_linked[local->index - 1]) { ret = -EBUSY; goto out; } csi2->sink_linked[local->index - 1] = true; } else { csi2->sink_linked[local->index - 1] = false; } } else { if (flags & MEDIA_LNK_FL_ENABLED) { if (csi2->src_sd) { ret = -EBUSY; goto out; } csi2->src_sd = remote_sd; } else { csi2->src_sd = NULL; } } out: mutex_unlock(&csi2->lock); return ret; } static struct v4l2_mbus_framefmt * __csi2_get_fmt(struct csi2_dev *csi2, struct v4l2_subdev_pad_config *cfg, unsigned int pad, enum v4l2_subdev_format_whence which) { if (which == V4L2_SUBDEV_FORMAT_TRY) return v4l2_subdev_get_try_format(&csi2->sd, cfg, pad); else return &csi2->format_mbus; } static int csi2_get_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_pad_config *cfg, struct v4l2_subdev_format *sdformat) { struct csi2_dev *csi2 = sd_to_dev(sd); struct v4l2_mbus_framefmt *fmt; mutex_lock(&csi2->lock); fmt = __csi2_get_fmt(csi2, cfg, sdformat->pad, sdformat->which); sdformat->format = *fmt; mutex_unlock(&csi2->lock); return 0; } static int csi2_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_pad_config *cfg, struct v4l2_subdev_format *sdformat) { struct csi2_dev *csi2 = sd_to_dev(sd); struct v4l2_mbus_framefmt *fmt; int ret = 0; if (sdformat->pad >= CSI2_NUM_PADS) return -EINVAL; mutex_lock(&csi2->lock); if (csi2->stream_count > 0) { ret = -EBUSY; goto out; } /* Output pads mirror active input pad, no limits on input pads */ if (sdformat->pad != CSI2_SINK_PAD) sdformat->format = csi2->format_mbus; fmt = __csi2_get_fmt(csi2, cfg, sdformat->pad, sdformat->which); *fmt = sdformat->format; out: mutex_unlock(&csi2->lock); return ret; } /* * retrieve our pads parsed from the OF graph by the media device */ static int csi2_registered(struct v4l2_subdev *sd) { struct csi2_dev *csi2 = sd_to_dev(sd); int i, ret; for (i = 0; i < CSI2_NUM_PADS; i++) { csi2->pad[i].flags = (i == CSI2_SINK_PAD) ? MEDIA_PAD_FL_SINK : MEDIA_PAD_FL_SOURCE; } /* set a default mbus format */ ret = imx_media_init_mbus_fmt(&csi2->format_mbus, 640, 480, 0, V4L2_FIELD_NONE, NULL); if (ret) return ret; return media_entity_pads_init(&sd->entity, CSI2_NUM_PADS, csi2->pad); } static const struct media_entity_operations csi2_entity_ops = { .link_setup = csi2_link_setup, .link_validate = v4l2_subdev_link_validate, }; static const struct v4l2_subdev_video_ops csi2_video_ops = { .s_stream = csi2_s_stream, }; static const struct v4l2_subdev_pad_ops csi2_pad_ops = { .init_cfg = imx_media_init_cfg, .get_fmt = csi2_get_fmt, .set_fmt = csi2_set_fmt, }; static const struct v4l2_subdev_ops csi2_subdev_ops = { .video = &csi2_video_ops, .pad = &csi2_pad_ops, }; static const struct v4l2_subdev_internal_ops csi2_internal_ops = { .registered = csi2_registered, }; static int csi2_parse_endpoint(struct device *dev, struct v4l2_fwnode_endpoint *vep, struct v4l2_async_subdev *asd) { struct v4l2_subdev *sd = dev_get_drvdata(dev); struct csi2_dev *csi2 = sd_to_dev(sd); if (!fwnode_device_is_available(asd->match.fwnode)) { v4l2_err(&csi2->sd, "remote is not available\n"); return -EINVAL; } if (vep->bus_type != V4L2_MBUS_CSI2_DPHY) { v4l2_err(&csi2->sd, "invalid bus type, must be MIPI CSI2\n"); return -EINVAL; } csi2->bus = vep->bus.mipi_csi2; dev_dbg(csi2->dev, "data lanes: %d\n", csi2->bus.num_data_lanes); dev_dbg(csi2->dev, "flags: 0x%08x\n", csi2->bus.flags); return 0; } static int csi2_probe(struct platform_device *pdev) { unsigned int sink_port = 0; struct csi2_dev *csi2; struct resource *res; int ret; csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL); if (!csi2) return -ENOMEM; csi2->dev = &pdev->dev; v4l2_subdev_init(&csi2->sd, &csi2_subdev_ops); v4l2_set_subdevdata(&csi2->sd, &pdev->dev); csi2->sd.internal_ops = &csi2_internal_ops; csi2->sd.entity.ops = &csi2_entity_ops; csi2->sd.dev = &pdev->dev; csi2->sd.owner = THIS_MODULE; csi2->sd.flags = V4L2_SUBDEV_FL_HAS_DEVNODE; strscpy(csi2->sd.name, DEVICE_NAME, sizeof(csi2->sd.name)); csi2->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE; csi2->sd.grp_id = IMX_MEDIA_GRP_ID_CSI2; csi2->pllref_clk = devm_clk_get(&pdev->dev, "ref"); if (IS_ERR(csi2->pllref_clk)) { v4l2_err(&csi2->sd, "failed to get pll reference clock\n"); ret = PTR_ERR(csi2->pllref_clk); return ret; } csi2->dphy_clk = devm_clk_get(&pdev->dev, "dphy"); if (IS_ERR(csi2->dphy_clk)) { v4l2_err(&csi2->sd, "failed to get dphy clock\n"); ret = PTR_ERR(csi2->dphy_clk); return ret; } csi2->pix_clk = devm_clk_get(&pdev->dev, "pix"); if (IS_ERR(csi2->pix_clk)) { v4l2_err(&csi2->sd, "failed to get pixel clock\n"); ret = PTR_ERR(csi2->pix_clk); return ret; } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { v4l2_err(&csi2->sd, "failed to get platform resources\n"); return -ENODEV; } csi2->base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE); if (!csi2->base) return -ENOMEM; mutex_init(&csi2->lock); ret = clk_prepare_enable(csi2->pllref_clk); if (ret) { v4l2_err(&csi2->sd, "failed to enable pllref_clk\n"); goto rmmutex; } ret = clk_prepare_enable(csi2->dphy_clk); if (ret) { v4l2_err(&csi2->sd, "failed to enable dphy_clk\n"); goto pllref_off; } platform_set_drvdata(pdev, &csi2->sd); ret = v4l2_async_register_fwnode_subdev( &csi2->sd, sizeof(struct v4l2_async_subdev), &sink_port, 1, csi2_parse_endpoint); if (ret) goto dphy_off; return 0; dphy_off: clk_disable_unprepare(csi2->dphy_clk); pllref_off: clk_disable_unprepare(csi2->pllref_clk); rmmutex: mutex_destroy(&csi2->lock); return ret; } static int csi2_remove(struct platform_device *pdev) { struct v4l2_subdev *sd = platform_get_drvdata(pdev); struct csi2_dev *csi2 = sd_to_dev(sd); v4l2_async_unregister_subdev(sd); clk_disable_unprepare(csi2->dphy_clk); clk_disable_unprepare(csi2->pllref_clk); mutex_destroy(&csi2->lock); media_entity_cleanup(&sd->entity); return 0; } static const struct of_device_id csi2_dt_ids[] = { { .compatible = "fsl,imx6-mipi-csi2", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, csi2_dt_ids); static struct platform_driver csi2_driver = { .driver = { .name = DEVICE_NAME, .of_match_table = csi2_dt_ids, }, .probe = csi2_probe, .remove = csi2_remove, }; module_platform_driver(csi2_driver); MODULE_DESCRIPTION("i.MX5/6 MIPI CSI-2 Receiver driver"); MODULE_AUTHOR("Steve Longerbeam "); MODULE_LICENSE("GPL");