Hi Peter, Am Donnerstag, den 27.10.2016, 15:01 +0200 schrieb Peter Senna Tschudin: > Add a driver that create a drm_bridge and a drm_connector for the LVDS > to DP++ display bridge of the GE B850v3. > > There are two physical bridges on the video signal pipeline: a > STDP4028(LVDS to DP) and a STDP2690(DP to DP++). The hardware and > firmware made it complicated for this binding to comprise two device > tree nodes, as the design goal is to configure both bridges based on > the LVDS signal, which leave the driver powerless to control the video > processing pipeline. The two bridges behaves as a single bridge, and > the driver is only needed for telling the host about EDID / HPD, and > for giving the host powers to ack interrupts. The video signal pipeline > is as follows: > > Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output > > Cc: Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx> > Cc: Martin Donnelly <martin.donnelly@xxxxxx> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > Cc: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx> > Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > Cc: Rob Herring <robh@xxxxxxxxxx> > Cc: Fabio Estevam <fabio.estevam@xxxxxxx> > CC: David Airlie <airlied@xxxxxxxx> > CC: Thierry Reding <treding@xxxxxxxxxx> > CC: Thierry Reding <thierry.reding@xxxxxxxxx> > CC: Archit Taneja <architt@xxxxxxxxxxxxxx> > Reviewed-by: Enric Balletbo <enric.balletbo@xxxxxxxxxxxxx> > Signed-off-by: Peter Senna Tschudin <peter.senna@xxxxxxxxxxxxx> > --- > Changes from V5: > - Reworked interrupt handler initialization > - Removed useless calls to: drm_connector_register(), > drm_helper_hpd_irq_event(), and drm_bridge_enable() > > Changes from V4: > - Renamed the i2c_driver.name from "ge,b850v3-lvds-dp" to "b850v3-lvds-dp" to > remove the comma from the driver name > > Changes from V3: > - 3/4 instead of 4/5 > - Tested on next-20160804 > > Changes from V2: > - Made it atomic to be applied on next-20160729 on top of Liu Ying changes > that made imx-ldb atomic > > Changes from V1: > - New commit message > - Removed 3 empty entry points > - Removed memory leak from ge_b850v3_lvds_dp_get_modes() > - Added a lock for mode setting > - Removed a few blank lines > - Changed the order at Makefile and Kconfig > > drivers/gpu/drm/bridge/Kconfig | 11 + > drivers/gpu/drm/bridge/Makefile | 1 + > drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c | 395 +++++++++++++++++++++++++++++ > 3 files changed, 407 insertions(+) > create mode 100644 drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c > > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig > index bd6acc8..1d02422 100644 > --- a/drivers/gpu/drm/bridge/Kconfig > +++ b/drivers/gpu/drm/bridge/Kconfig > @@ -39,6 +39,17 @@ config DRM_DW_HDMI_AHB_AUDIO > Designware HDMI block. This is used in conjunction with > the i.MX6 HDMI driver. > > +config DRM_GE_B850V3_LVDS_DP > + tristate "GE B850v3 LVDS to DP++ display bridge" > + depends on OF > + select DRM_KMS_HELPER > + select DRM_PANEL > + ---help--- > + This is a driver for the display bridge of > + GE B850v3 that convert dual channel LVDS > + to DP++. This is used with the i.MX6 imx-ldb > + driver. > + > config DRM_NXP_PTN3460 > tristate "NXP PTN3460 DP/LVDS bridge" > depends on OF > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile > index 97ed1a5..b6b44a5 100644 > --- a/drivers/gpu/drm/bridge/Makefile > +++ b/drivers/gpu/drm/bridge/Makefile > @@ -5,6 +5,7 @@ obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o > obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o > obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o > obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o > +obj-$(CONFIG_DRM_GE_B850V3_LVDS_DP) += ge_b850v3_lvds_dp.o > obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o > obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o > obj-$(CONFIG_DRM_SII902X) += sii902x.o > diff --git a/drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c b/drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c > new file mode 100644 > index 0000000..85875d8 > --- /dev/null > +++ b/drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c > @@ -0,0 +1,395 @@ > +/* > + * Driver for GE B850v3 DP display bridge > + > + * Copyright (c) 2016, Collabora Ltd. > + * Copyright (c) 2016, General Electric Company > + > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + > + * This driver creates a drm_bridge and a drm_connector for the LVDS to DP++ > + * display bridge of the GE B850v3. There are two physical bridges on the video > + * signal pipeline: a STDP4028(LVDS to DP) and a STDP2690(DP to DP++). However > + * the physical bridges are automatically configured by the input video signal, > + * and the driver has no access to the video processing pipeline. The driver is > + * only needed to read EDID from the STDP2690 and to handle HPD events from the > + * STDP4028. The driver communicates with both bridges over i2c. The video > + * signal pipeline is as follows: > + * > + * Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output > + * > + */ > + > +#include <linux/gpio.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <drm/drm_atomic.h> > +#include <drm/drm_atomic_helper.h> > +#include <drm/drm_crtc_helper.h> > +#include <drm/drm_edid.h> > +#include <drm/drmP.h> > + > +/* > + * 220Mhz is a limitation of the host, as the bridge is capable of up to > + * 330Mhz. See section 9.2.1.2.4 of the i.MX 6Dual/6Quad Applications > + * Processor Reference Manual for more information about the 220Mhz limit. > + * The imx-ldb driver will warn about clocks over 170Mhz, but it seem to work > + * fine. > + */ > +#define MAX_PIXEL_CLOCK 220000 That is a limitation of the IPU DI pixel clock rate if both DIs are active. If only a single DI is active, this limit is 264 MHz on i.MX6Q. The LDB pixel clock rate maximum is 170 MHz if only a single LDB channel is active. I currently see no way for the crtc and encoder code to have a say about maximum pixel clocks when pruning the mode list in .fill_modes. > + > +#define EDID_EXT_BLOCK_CNT 0x7E > + > +#define STDP4028_IRQ_OUT_CONF_REG 0x02 > +#define STDP4028_DPTX_IRQ_EN_REG 0x3C > +#define STDP4028_DPTX_IRQ_STS_REG 0x3D > +#define STDP4028_DPTX_STS_REG 0x3E > + > +#define STDP4028_DPTX_DP_IRQ_EN 0x1000 > + > +#define STDP4028_DPTX_HOTPLUG_IRQ_EN 0x0400 > +#define STDP4028_DPTX_LINK_CH_IRQ_EN 0x2000 > +#define STDP4028_DPTX_IRQ_CONFIG \ > + (STDP4028_DPTX_LINK_CH_IRQ_EN | STDP4028_DPTX_HOTPLUG_IRQ_EN) > + > +#define STDP4028_DPTX_HOTPLUG_STS 0x0200 > +#define STDP4028_DPTX_LINK_STS 0x1000 > +#define STDP4028_CON_STATE_CONNECTED \ > + (STDP4028_DPTX_HOTPLUG_STS | STDP4028_DPTX_LINK_STS) > + > +#define STDP4028_DPTX_HOTPLUG_CH_STS 0x0400 > +#define STDP4028_DPTX_LINK_CH_STS 0x2000 > +#define STDP4028_DPTX_IRQ_CLEAR \ > + (STDP4028_DPTX_LINK_CH_STS | STDP4028_DPTX_HOTPLUG_CH_STS) > + > +struct ge_b850v3_lvds_dp { > + struct drm_connector connector; > + struct drm_bridge bridge; > + struct i2c_client *ge_b850v3_lvds_dp_i2c; > + struct i2c_client *edid_i2c; > + struct edid *edid; > + struct mutex lock; > +}; > + > +static inline struct ge_b850v3_lvds_dp * > + bridge_to_ge_b850v3_lvds_dp(struct drm_bridge *bridge) > +{ > + return container_of(bridge, struct ge_b850v3_lvds_dp, bridge); > +} > + > +static inline struct ge_b850v3_lvds_dp * > + connector_to_ge_b850v3_lvds_dp(struct drm_connector *connector) > +{ > + return container_of(connector, struct ge_b850v3_lvds_dp, connector); > +} > + > +u8 *stdp2690_get_edid(struct i2c_client *client) > +{ > + struct i2c_adapter *adapter = client->adapter; > + unsigned char start = 0x00; > + unsigned int total_size; > + u8 *block = kmalloc(EDID_LENGTH, GFP_KERNEL); > + > + struct i2c_msg msgs[] = { > + { > + .addr = client->addr, > + .flags = 0, > + .len = 1, > + .buf = &start, > + }, { > + .addr = client->addr, > + .flags = I2C_M_RD, > + .len = EDID_LENGTH, > + .buf = block, > + } > + }; > + > + if (!block) > + return NULL; > + > + if (i2c_transfer(adapter, msgs, 2) != 2) { > + DRM_ERROR("Unable to read EDID.\n"); > + goto err; > + } > + > + if (!drm_edid_block_valid(block, 0, false, NULL)) { > + DRM_ERROR("Invalid EDID block\n"); > + goto err; > + } > + > + total_size = (block[EDID_EXT_BLOCK_CNT] + 1) * EDID_LENGTH; > + if (total_size > EDID_LENGTH) { > + kfree(block); > + block = kmalloc(total_size, GFP_KERNEL); > + if (!block) > + return NULL; > + > + /* Yes, read the entire buffer, and do not skip the first > + * EDID_LENGTH bytes. > + */ > + start = 0x00; > + msgs[1].len = total_size; > + msgs[1].buf = block; > + > + if (i2c_transfer(adapter, msgs, 2) != 2) { > + DRM_ERROR("Unable to read EDID extension blocks.\n"); > + goto err; > + } > + } > + > + return block; > + > +err: > + kfree(block); > + return NULL; > +} > + > +static int ge_b850v3_lvds_dp_get_modes(struct drm_connector *connector) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge; > + struct i2c_client *client; > + int num_modes = 0; > + > + ptn_bridge = connector_to_ge_b850v3_lvds_dp(connector); > + client = ptn_bridge->edid_i2c; > + > + mutex_lock(&ptn_bridge->lock); What does this lock protect? > + kfree(ptn_bridge->edid); > + ptn_bridge->edid = (struct edid *) stdp2690_get_edid(client); > + > + if (ptn_bridge->edid) { > + drm_mode_connector_update_edid_property(connector, > + ptn_bridge->edid); > + num_modes = drm_add_edid_modes(connector, ptn_bridge->edid); > + } > + > + mutex_unlock(&ptn_bridge->lock); > + > + return num_modes; > +} > + > + > +static enum drm_mode_status ge_b850v3_lvds_dp_mode_valid( > + struct drm_connector *connector, struct drm_display_mode *mode) > +{ > + if (mode->clock > MAX_PIXEL_CLOCK) { > + DRM_INFO("The pixel clock for the mode %s is too high, and not supported.", > + mode->name); > + return MODE_CLOCK_HIGH; > + } > + > + return MODE_OK; > +} > + > +static const struct > +drm_connector_helper_funcs ge_b850v3_lvds_dp_connector_helper_funcs = { > + .get_modes = ge_b850v3_lvds_dp_get_modes, > + .mode_valid = ge_b850v3_lvds_dp_mode_valid, > +}; > + > +static enum drm_connector_status ge_b850v3_lvds_dp_detect( > + struct drm_connector *connector, bool force) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge = > + connector_to_ge_b850v3_lvds_dp(connector); > + struct i2c_client *ge_b850v3_lvds_dp_i2c = > + ptn_bridge->ge_b850v3_lvds_dp_i2c; > + s32 link_state; > + > + link_state = i2c_smbus_read_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_STS_REG); > + > + if (link_state == STDP4028_CON_STATE_CONNECTED) > + return connector_status_connected; > + > + if (link_state == 0) > + return connector_status_disconnected; > + > + return connector_status_unknown; > +} > + > +static const struct drm_connector_funcs ge_b850v3_lvds_dp_connector_funcs = { > + .dpms = drm_atomic_helper_connector_dpms, > + .fill_modes = drm_helper_probe_single_connector_modes, > + .detect = ge_b850v3_lvds_dp_detect, > + .destroy = drm_connector_cleanup, > + .reset = drm_atomic_helper_connector_reset, > + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, > + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, > +}; > + > +static irqreturn_t ge_b850v3_lvds_dp_irq_handler(int irq, void *dev_id) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge = dev_id; > + struct i2c_client *ge_b850v3_lvds_dp_i2c > + = ptn_bridge->ge_b850v3_lvds_dp_i2c; > + > + mutex_lock(&ptn_bridge->lock); And what does this lock protect here? > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_STS_REG, STDP4028_DPTX_IRQ_CLEAR); > + > + mutex_unlock(&ptn_bridge->lock); > + > + if (ptn_bridge->connector.dev) > + drm_kms_helper_hotplug_event(ptn_bridge->connector.dev); > + > + return IRQ_HANDLED; > +} > + > +static int ge_b850v3_lvds_dp_attach(struct drm_bridge *bridge) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge > + = bridge_to_ge_b850v3_lvds_dp(bridge); > + struct drm_connector *connector = &ptn_bridge->connector; > + struct i2c_client *ge_b850v3_lvds_dp_i2c > + = ptn_bridge->ge_b850v3_lvds_dp_i2c; > + int ret; > + > + if (!bridge->encoder) { > + DRM_ERROR("Parent encoder object not found"); > + return -ENODEV; > + } > + > + connector->polled = DRM_CONNECTOR_POLL_HPD; > + > + drm_connector_helper_add(connector, > + &ge_b850v3_lvds_dp_connector_helper_funcs); > + > + ret = drm_connector_init(bridge->dev, connector, > + &ge_b850v3_lvds_dp_connector_funcs, > + DRM_MODE_CONNECTOR_DisplayPort); > + if (ret) { > + DRM_ERROR("Failed to initialize connector with drm\n"); > + return ret; > + } > + > + ret = drm_mode_connector_attach_encoder(connector, bridge->encoder); > + if (ret) > + return ret; > + > + /* Configures the bridge to re-enable interrupts after each ack. */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_IRQ_OUT_CONF_REG, STDP4028_DPTX_DP_IRQ_EN); > + > + /* Enable interrupts */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_EN_REG, STDP4028_DPTX_IRQ_CONFIG); > + > + return 0; > +} > + > +static const struct drm_bridge_funcs ge_b850v3_lvds_dp_funcs = { > + .attach = ge_b850v3_lvds_dp_attach, What about .detach? Should the interrupt be disabled? > +}; > + > +static int ge_b850v3_lvds_dp_probe(struct i2c_client *ge_b850v3_lvds_dp_i2c, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &ge_b850v3_lvds_dp_i2c->dev; > + struct ge_b850v3_lvds_dp *ptn_bridge; > + int ret; > + u32 edid_i2c_reg; > + > + ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); > + if (!ptn_bridge) > + return -ENOMEM; > + > + mutex_init(&ptn_bridge->lock); > + > + ptn_bridge->ge_b850v3_lvds_dp_i2c = ge_b850v3_lvds_dp_i2c; > + ptn_bridge->bridge.driver_private = ptn_bridge; > + i2c_set_clientdata(ge_b850v3_lvds_dp_i2c, ptn_bridge); > + > + ret = of_property_read_u32(dev->of_node, "edid-reg", &edid_i2c_reg); > + if (ret) { > + dev_err(dev, "edid-reg not specified, aborting...\n"); > + return -ENODEV; > + } > + > + ptn_bridge->edid_i2c = devm_kzalloc(dev, > + sizeof(struct i2c_client), GFP_KERNEL); > + Superfluous empty line, but ... > + if (!ptn_bridge->edid_i2c) > + return -ENOMEM; > + > + memcpy(ptn_bridge->edid_i2c, ge_b850v3_lvds_dp_i2c, > + sizeof(struct i2c_client)); > + > + ptn_bridge->edid_i2c->addr = (unsigned short) edid_i2c_reg; ... this looks to me like you should use i2c_new_dummy, or rather i2c_new_secondary_device instead. For the latter you'd have to change the bindings to use reg and reg-names properties instead of the custom edid-reg property. > + > + ptn_bridge->bridge.funcs = &ge_b850v3_lvds_dp_funcs; > + ptn_bridge->bridge.of_node = dev->of_node; > + ret = drm_bridge_add(&ptn_bridge->bridge); > + if (ret) { > + DRM_ERROR("Failed to add bridge\n"); > + return ret; > + } Just as a note, this currently can not fail. It's just a list_add_tail under a mutex lock. If it would fail though, it'd be nice to also print the error code. > + > + /* Clear pending interrupts since power up. */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_STS_REG, STDP4028_DPTX_IRQ_CLEAR); > + > + if (ge_b850v3_lvds_dp_i2c->irq) { > + ret = devm_request_threaded_irq(&ge_b850v3_lvds_dp_i2c->dev, > + ge_b850v3_lvds_dp_i2c->irq, NULL, > + ge_b850v3_lvds_dp_irq_handler, > + IRQF_TRIGGER_HIGH | IRQF_ONESHOT, > + "ge-b850v3-lvds-dp", ptn_bridge); > + if (ret) > + return ret; > + } > + > + return 0; Maybe a matter of taste, but this could be changed to: /* If no interrupt has to be requested, we're done here */ if (!ge_b850v3_lvds_dp_i2c->irq) return 0; return devm_request_threaded_irq(&ge_b850v3_lvds_dp_i2c->dev, ge_b850v3_lvds_dp_i2c->irq, NULL, ge_b850v3_lvds_dp_irq_handler, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "ge-b850v3-lvds-dp", ptn_bridge); or, as we know ret to be 0 after the call to drm_bridge_add: if (ge_b850v3_lvds_dp_i2c->irq) { ret = devm_request_threaded_irq(&ge_b850v3_lvds_dp_i2c->dev, ge_b850v3_lvds_dp_i2c->irq, NULL, ge_b850v3_lvds_dp_irq_handler, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "ge-b850v3-lvds-dp", ptn_bridge); } return ret; > +} > + > +static int ge_b850v3_lvds_dp_remove(struct i2c_client *ge_b850v3_lvds_dp_i2c) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge = > + i2c_get_clientdata(ge_b850v3_lvds_dp_i2c); > + > + drm_bridge_remove(&ptn_bridge->bridge); > + > + kfree(ptn_bridge->edid); > + > + return 0; > +} > + > +static const struct i2c_device_id ge_b850v3_lvds_dp_i2c_table[] = { > + {"b850v3-lvds-dp", 0}, > + {}, > +}; > +MODULE_DEVICE_TABLE(i2c, ge_b850v3_lvds_dp_i2c_table); > + > +static const struct of_device_id ge_b850v3_lvds_dp_match[] = { > + { .compatible = "ge,b850v3-lvds-dp" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, ge_b850v3_lvds_dp_match); > + > +static struct i2c_driver ge_b850v3_lvds_dp_driver = { > + .id_table = ge_b850v3_lvds_dp_i2c_table, > + .probe = ge_b850v3_lvds_dp_probe, > + .remove = ge_b850v3_lvds_dp_remove, > + .driver = { > + .name = "b850v3-lvds-dp", > + .of_match_table = ge_b850v3_lvds_dp_match, > + }, > +}; > +module_i2c_driver(ge_b850v3_lvds_dp_driver); > + > +MODULE_AUTHOR("Peter Senna Tschudin <peter.senna@xxxxxxxxxxxxx>"); > +MODULE_AUTHOR("Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("GE LVDS to DP++ display bridge)"); > +MODULE_LICENSE("GPL v2"); regards Philipp -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
