Hi Archit, Thank you for the review!
On Wed, Mar 01, 2017 at 09:38:48AM +0530, Archit Taneja wrote: > > > On 02/28/2017 07:58 PM, Peter Senna Tschudin wrote: > > The video processing pipeline on the second output on the GE B850v3: > > > > Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output > > > > Each bridge has a dedicated flash containing firmware for supporting the > > custom design. The result is that in this design neither the STDP4028 > > nor the STDP2690 behave as the stock bridges would. The compatible > > strings include the suffix "-ge-b850v3-fw" to make it clear that the > > driver is for the bridges with the firmware which is specific for the GE > > B850v3. > > > > The driver is powerless to control the video processing pipeline, as the > > two bridges behaves as a single one. The driver is only needed for > > telling the host about EDID / HPD, and for giving the host powers to ack > > interrupts. > > > > This driver adds one i2c_device for each bridge, but only one > > drm_bridge. This design allows the creation of a functional connector > > that is capable of reading EDID from the STDP2690 while handling > > interrupts on the STDP4028. > > > > Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com> > > Cc: Martyn Welch <martyn.we...@collabora.co.uk> > > Cc: Martin Donnelly <martin.donne...@ge.com> > > Cc: Daniel Vetter <daniel.vet...@ffwll.ch> > > Cc: Enric Balletbo i Serra <enric.balle...@collabora.com> > > Cc: Philipp Zabel <p.za...@pengutronix.de> > > Cc: Rob Herring <r...@kernel.org> > > Cc: Fabio Estevam <fabio.este...@nxp.com> > > Cc: David Airlie <airl...@linux.ie> > > Cc: Thierry Reding <tred...@nvidia.com> > > Cc: Thierry Reding <thierry.red...@gmail.com> > > Cc: Archit Taneja <arch...@codeaurora.org> > > Cc: Enric Balletbo <enric.balle...@collabora.com> > > Signed-off-by: Peter Senna Tschudin <peter.se...@collabora.com> > > --- > > Changes from V1: > > - Updated copyright year > > - Fixed blank line issues > > - Updated ge_b850v3_lvds_remove() to not rely on ge_b850v3_lvds_ptr->edid > > and > > added a comment to explain the test. > > - Fixed checkpatch strict warnings about continuation lines. In one case > > fixing the warning would cause the continuation line to be over 80 chars > > and > > that strict warning remains. > > > > drivers/gpu/drm/bridge/Kconfig | 11 + > > drivers/gpu/drm/bridge/Makefile | 1 + > > .../drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 411 > > +++++++++++++++++++++ > > 3 files changed, 423 insertions(+) > > create mode 100644 drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > > > > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig > > index eb8688e..4a937f1 100644 > > --- a/drivers/gpu/drm/bridge/Kconfig > > +++ b/drivers/gpu/drm/bridge/Kconfig > > @@ -48,6 +48,17 @@ config DRM_DW_HDMI_I2S_AUDIO > > Support the I2S Audio interface which is part of the Synopsis > > Designware HDMI block. > > > > +config DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW > > + tristate "MegaChips stdp4028-ge-b850v3-fw and stdp2690-ge-b850v3-fw" > > + depends on OF > > + select DRM_KMS_HELPER > > + select DRM_PANEL > > + ---help--- > > + This is a driver for the display bridges of > > + GE B850v3 that convert dual channel LVDS > > + to DP++. This is used with the i.MX6 imx-ldb > > + driver. You are likely to say N here. > > + > > 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 2e83a785..af0b7cc 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_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o > > +obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += > > megachips-stdpxxxx-ge-b850v3-fw.o > > obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o > > obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o > > obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o > > diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > > b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > > new file mode 100644 > > index 0000000..6f82a44 > > --- /dev/null > > +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c > > @@ -0,0 +1,411 @@ > > +/* > > + * Driver for MegaChips STDP4028 with GE B850v3 firmware (LVDS-DP) > > + * Driver for MegaChips STDP2690 with GE B850v3 firmware (DP-DP++) > > + > > + * Copyright (c) 2017, Collabora Ltd. > > + * Copyright (c) 2017, 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++). 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> > > + > > +#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) > > + > > +static DEFINE_MUTEX(ge_b850v3_lvds_dev_mutex); > > + > > +struct ge_b850v3_lvds { > > + struct drm_connector connector; > > + struct drm_bridge bridge; > > + struct i2c_client *stdp4028_i2c; > > + struct i2c_client *stdp2690_i2c; > > + struct edid *edid; > > +}; > > + > > +static struct ge_b850v3_lvds *ge_b850v3_lvds_ptr; > > + > > +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 data\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; > > + } > > + if (!drm_edid_block_valid(block, 1, false, NULL)) { > > + DRM_ERROR("Invalid EDID data\n"); > > + goto err; > > + } > > + } > > + > > + return block; > > + > > +err: > > + kfree(block); > > + return NULL; > > +} > > + > > +static int ge_b850v3_lvds_get_modes(struct drm_connector *connector) > > +{ > > + struct i2c_client *client; > > + int num_modes = 0; > > + > > + client = ge_b850v3_lvds_ptr->stdp2690_i2c; > > + > > + kfree(ge_b850v3_lvds_ptr->edid); > > + ge_b850v3_lvds_ptr->edid = (struct edid *)stdp2690_get_edid(client); > > + > > + if (ge_b850v3_lvds_ptr->edid) { > > + drm_mode_connector_update_edid_property(connector, > > + ge_b850v3_lvds_ptr->edid); > > + num_modes = drm_add_edid_modes(connector, > > + ge_b850v3_lvds_ptr->edid); > > + } > > + > > + return num_modes; > > +} > > + > > +static enum drm_mode_status ge_b850v3_lvds_mode_valid( > > + struct drm_connector *connector, struct drm_display_mode *mode) > > +{ > > + return MODE_OK; > > +} > > + > > +static const struct > > +drm_connector_helper_funcs ge_b850v3_lvds_connector_helper_funcs = { > > + .get_modes = ge_b850v3_lvds_get_modes, > > + .mode_valid = ge_b850v3_lvds_mode_valid, > > +}; > > + > > +static enum drm_connector_status ge_b850v3_lvds_detect( > > + struct drm_connector *connector, bool force) > > +{ > > + struct i2c_client *stdp4028_i2c = > > + ge_b850v3_lvds_ptr->stdp4028_i2c; > > + s32 link_state; > > + > > + link_state = i2c_smbus_read_word_data(stdp4028_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_connector_funcs = { > > + .dpms = drm_atomic_helper_connector_dpms, > > + .fill_modes = drm_helper_probe_single_connector_modes, > > + .detect = ge_b850v3_lvds_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_irq_handler(int irq, void *dev_id) > > +{ > > + struct i2c_client *stdp4028_i2c > > + = ge_b850v3_lvds_ptr->stdp4028_i2c; > > + > > + i2c_smbus_write_word_data(stdp4028_i2c, > > + STDP4028_DPTX_IRQ_STS_REG, > > + STDP4028_DPTX_IRQ_CLEAR); > > + > > + if (ge_b850v3_lvds_ptr->connector.dev) > > + drm_kms_helper_hotplug_event(ge_b850v3_lvds_ptr->connector.dev); > > + > > + return IRQ_HANDLED; > > +} > > + > > +static int ge_b850v3_lvds_attach(struct drm_bridge *bridge) > > +{ > > + struct drm_connector *connector = &ge_b850v3_lvds_ptr->connector; > > + struct i2c_client *stdp4028_i2c > > + = ge_b850v3_lvds_ptr->stdp4028_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_connector_helper_funcs); > > + > > + ret = drm_connector_init(bridge->dev, connector, > > + &ge_b850v3_lvds_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(stdp4028_i2c, > > + STDP4028_IRQ_OUT_CONF_REG, > > + STDP4028_DPTX_DP_IRQ_EN); > > + > > + /* Enable interrupts */ > > + i2c_smbus_write_word_data(stdp4028_i2c, > > + STDP4028_DPTX_IRQ_EN_REG, > > + STDP4028_DPTX_IRQ_CONFIG); > > + > > + return 0; > > +} > > + > > +static const struct drm_bridge_funcs ge_b850v3_lvds_funcs = { > > + .attach = ge_b850v3_lvds_attach, > > +}; > > + > > +static int ge_b850v3_lvds_init(struct device *dev) > > +{ > > + mutex_lock(&ge_b850v3_lvds_dev_mutex); > > + > > + if (ge_b850v3_lvds_ptr) > > + goto success; > > + > > + ge_b850v3_lvds_ptr = devm_kzalloc(dev, > > + sizeof(*ge_b850v3_lvds_ptr), > > + GFP_KERNEL); > > + > > + if (!ge_b850v3_lvds_ptr) { > > + mutex_unlock(&ge_b850v3_lvds_dev_mutex); > > + return -ENOMEM; > > + } > > + > > + ge_b850v3_lvds_ptr->bridge.funcs = &ge_b850v3_lvds_funcs; > > + ge_b850v3_lvds_ptr->bridge.of_node = dev->of_node; > > + drm_bridge_add(&ge_b850v3_lvds_ptr->bridge); > > + > > +success: > > + mutex_unlock(&ge_b850v3_lvds_dev_mutex); > > + return 0; > > +} > > + > > +static void ge_b850v3_lvds_remove(void) > > +{ > > + mutex_lock(&ge_b850v3_lvds_dev_mutex); > > + /* > > + * This check is to avoid both the drivers > > + * removing the bridge in their remove() function > > + */ > > + if (!ge_b850v3_lvds_ptr) > > + goto out; > > + > > + drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge); > > + > > + kfree(ge_b850v3_lvds_ptr->edid); > > + > > + ge_b850v3_lvds_ptr = NULL; > > +out: > > + mutex_unlock(&ge_b850v3_lvds_dev_mutex); > > +} > > + > > +static int stdp4028_ge_b850v3_fw_probe(struct i2c_client *stdp4028_i2c, > > + const struct i2c_device_id *id) > > +{ > > + struct device *dev = &stdp4028_i2c->dev; > > + > > + ge_b850v3_lvds_init(dev); > > + > > + ge_b850v3_lvds_ptr->stdp4028_i2c = stdp4028_i2c; > > + i2c_set_clientdata(stdp4028_i2c, ge_b850v3_lvds_ptr); > > + > > + /* Clear pending interrupts since power up. */ > > + i2c_smbus_write_word_data(stdp4028_i2c, > > + STDP4028_DPTX_IRQ_STS_REG, > > + STDP4028_DPTX_IRQ_CLEAR); > > + > > + if (!stdp4028_i2c->irq) > > + return 0; > > + > > + return devm_request_threaded_irq(&stdp4028_i2c->dev, > > + stdp4028_i2c->irq, NULL, > > + ge_b850v3_lvds_irq_handler, > > + IRQF_TRIGGER_HIGH | IRQF_ONESHOT, > > + "ge-b850v3-lvds-dp", ge_b850v3_lvds_ptr); > > +} > > + > > +static int stdp4028_ge_b850v3_fw_remove(struct i2c_client *stdp4028_i2c) > > +{ > > + ge_b850v3_lvds_remove(); > > + > > + return 0; > > +} > > + > > +static const struct i2c_device_id stdp4028_ge_b850v3_fw_i2c_table[] = { > > + {"stdp4028_ge_fw", 0}, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(i2c, stdp4028_ge_b850v3_fw_i2c_table); > > + > > +static const struct of_device_id stdp4028_ge_b850v3_fw_match[] = { > > + { .compatible = "megachips,stdp4028-ge-b850v3-fw" }, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(of, stdp4028_ge_b850v3_fw_match); > > + > > +static struct i2c_driver stdp4028_ge_b850v3_fw_driver = { > > + .id_table = stdp4028_ge_b850v3_fw_i2c_table, > > + .probe = stdp4028_ge_b850v3_fw_probe, > > + .remove = stdp4028_ge_b850v3_fw_remove, > > + .driver = { > > + .name = "stdp4028-ge-b850v3-fw", > > + .of_match_table = stdp4028_ge_b850v3_fw_match, > > + }, > > +}; > > +module_i2c_driver(stdp4028_ge_b850v3_fw_driver); > > + > > +static int stdp2690_ge_b850v3_fw_probe(struct i2c_client *stdp2690_i2c, > > + const struct i2c_device_id *id) > > +{ > > + struct device *dev = &stdp2690_i2c->dev; > > + > > + ge_b850v3_lvds_init(dev); > > + > > + ge_b850v3_lvds_ptr->stdp2690_i2c = stdp2690_i2c; > > + i2c_set_clientdata(stdp2690_i2c, ge_b850v3_lvds_ptr); > > + > > + return 0; > > +} > > + > > +static int stdp2690_ge_b850v3_fw_remove(struct i2c_client *stdp2690_i2c) > > +{ > > + ge_b850v3_lvds_remove(); > > + > > + return 0; > > +} > > + > > +static const struct i2c_device_id stdp2690_ge_b850v3_fw_i2c_table[] = { > > + {"stdp2690_ge_fw", 0}, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(i2c, stdp2690_ge_b850v3_fw_i2c_table); > > + > > +static const struct of_device_id stdp2690_ge_b850v3_fw_match[] = { > > + { .compatible = "megachips,stdp2690-ge-b850v3-fw" }, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(of, stdp2690_ge_b850v3_fw_match); > > + > > +static struct i2c_driver stdp2690_ge_b850v3_fw_driver = { > > + .id_table = stdp2690_ge_b850v3_fw_i2c_table, > > + .probe = stdp2690_ge_b850v3_fw_probe, > > + .remove = stdp2690_ge_b850v3_fw_remove, > > + .driver = { > > + .name = "stdp2690-ge-b850v3-fw", > > + .of_match_table = stdp2690_ge_b850v3_fw_match, > > + }, > > +}; > > +module_i2c_driver(stdp2690_ge_b850v3_fw_driver); > > Didn't catch this in the last series, but there can only be one > module_init call per module. This breaks compilation when the > driver is built as a module. Unfortunately yes. Got loads of errors when trying to compile as a module. > > You could do something like: > > static int __init stdpxxxx_ge_b850v3_init(void) > { > int ret; > > ret = i2c_add_driver(&stdp4028_ge_b850v3_fw_driver); > if (ret) > return ret; > > return i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); > } > module_init(stdpxxxx_ge_b850v3_init); > > static void __exit stdpxxxx_ge_b850v3_exit(void) > { > i2c_del_driver(&stdp2690_ge_b850v3_fw_driver); > i2c_del_driver(&stdp4028_ge_b850v3_fw_driver); > } > module_exit(stdpxxxx_ge_b850v3_exit); Thank you! I was wondering if merging ge_b850v3_lvds_init() with stdpxxxx_ge_b850v3_init() and ge_b850v3_lvds_remove() with stdpxxxx_ge_b850v3_exit() make sense as it can probably eliminate the need for the mutex. > > Thanks, > Archit > > > + > > +MODULE_AUTHOR("Peter Senna Tschudin <peter.se...@collabora.com>"); > > +MODULE_AUTHOR("Martyn Welch <martyn.we...@collabora.co.uk>"); > > +MODULE_DESCRIPTION("GE LVDS to DP++ display bridge)"); > > +MODULE_LICENSE("GPL v2"); > > > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project
