diff options
Diffstat (limited to 'drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 407 |
1 files changed, 407 insertions, 0 deletions
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 000000000000..c9e6505cbd88 --- /dev/null +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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 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/i2c.h> +#include <linux/module.h> +#include <linux/of.h> + +#include <drm/drm_atomic.h> +#include <drm/drm_atomic_helper.h> +#include <drm/drm_bridge.h> +#include <drm/drm_edid.h> +#include <drm/drm_print.h> +#include <drm/drm_probe_helper.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; +}; + +static struct ge_b850v3_lvds *ge_b850v3_lvds_ptr; + +static int stdp2690_read_block(void *context, u8 *buf, unsigned int block, size_t len) +{ + struct i2c_client *client = context; + struct i2c_adapter *adapter = client->adapter; + unsigned char start = block * EDID_LENGTH; + + struct i2c_msg msgs[] = { + { + .addr = client->addr, + .flags = 0, + .len = 1, + .buf = &start, + }, { + .addr = client->addr, + .flags = I2C_M_RD, + .len = len, + .buf = buf, + } + }; + + if (i2c_transfer(adapter, msgs, 2) != 2) + return -1; + + return 0; +} + +static const struct drm_edid *ge_b850v3_lvds_edid_read(struct drm_bridge *bridge, + struct drm_connector *connector) +{ + struct i2c_client *client; + + client = ge_b850v3_lvds_ptr->stdp2690_i2c; + + return drm_edid_read_custom(connector, stdp2690_read_block, client); +} + +static int ge_b850v3_lvds_get_modes(struct drm_connector *connector) +{ + const struct drm_edid *drm_edid; + int num_modes; + + drm_edid = ge_b850v3_lvds_edid_read(&ge_b850v3_lvds_ptr->bridge, connector); + + drm_edid_connector_update(connector, drm_edid); + num_modes = drm_edid_connector_add_modes(connector); + drm_edid_free(drm_edid); + + return num_modes; +} + +static const struct +drm_connector_helper_funcs ge_b850v3_lvds_connector_helper_funcs = { + .get_modes = ge_b850v3_lvds_get_modes, +}; + +static enum drm_connector_status +ge_b850v3_lvds_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector) +{ + 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 enum drm_connector_status ge_b850v3_lvds_detect(struct drm_connector *connector, + bool force) +{ + return ge_b850v3_lvds_bridge_detect(&ge_b850v3_lvds_ptr->bridge, connector); +} + +static const struct drm_connector_funcs ge_b850v3_lvds_connector_funcs = { + .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 int ge_b850v3_lvds_create_connector(struct drm_bridge *bridge) +{ + struct drm_connector *connector = &ge_b850v3_lvds_ptr->connector; + int ret; + + 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; + } + + return drm_connector_attach_encoder(connector, bridge->encoder); +} + +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->bridge.dev) + drm_kms_helper_hotplug_event(ge_b850v3_lvds_ptr->bridge.dev); + + return IRQ_HANDLED; +} + +static int ge_b850v3_lvds_attach(struct drm_bridge *bridge, + struct drm_encoder *encoder, + enum drm_bridge_attach_flags flags) +{ + struct i2c_client *stdp4028_i2c + = ge_b850v3_lvds_ptr->stdp4028_i2c; + + /* 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); + + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) + return 0; + + return ge_b850v3_lvds_create_connector(bridge); +} + +static const struct drm_bridge_funcs ge_b850v3_lvds_funcs = { + .attach = ge_b850v3_lvds_attach, + .detect = ge_b850v3_lvds_bridge_detect, + .edid_read = ge_b850v3_lvds_edid_read, +}; + +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_drm_bridge_alloc(dev, struct ge_b850v3_lvds, bridge, + &ge_b850v3_lvds_funcs); + if (IS_ERR(ge_b850v3_lvds_ptr)) { + mutex_unlock(&ge_b850v3_lvds_dev_mutex); + return PTR_ERR(ge_b850v3_lvds_ptr); + } + +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 || + !ge_b850v3_lvds_ptr->stdp2690_i2c || + !ge_b850v3_lvds_ptr->stdp4028_i2c) + goto out; + + drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge); + + ge_b850v3_lvds_ptr = NULL; +out: + mutex_unlock(&ge_b850v3_lvds_dev_mutex); +} + +static int ge_b850v3_register(void) +{ + struct i2c_client *stdp4028_i2c = ge_b850v3_lvds_ptr->stdp4028_i2c; + struct device *dev = &stdp4028_i2c->dev; + + /* drm bridge initialization */ + ge_b850v3_lvds_ptr->bridge.ops = DRM_BRIDGE_OP_DETECT | + DRM_BRIDGE_OP_EDID; + ge_b850v3_lvds_ptr->bridge.type = DRM_MODE_CONNECTOR_DisplayPort; + ge_b850v3_lvds_ptr->bridge.of_node = dev->of_node; + drm_bridge_add(&ge_b850v3_lvds_ptr->bridge); + + /* 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_probe(struct i2c_client *stdp4028_i2c) +{ + struct device *dev = &stdp4028_i2c->dev; + int ret; + + ret = ge_b850v3_lvds_init(dev); + + if (ret) + return ret; + + ge_b850v3_lvds_ptr->stdp4028_i2c = stdp4028_i2c; + i2c_set_clientdata(stdp4028_i2c, ge_b850v3_lvds_ptr); + + /* Only register after both bridges are probed */ + if (!ge_b850v3_lvds_ptr->stdp2690_i2c) + return 0; + + return ge_b850v3_register(); +} + +static void stdp4028_ge_b850v3_fw_remove(struct i2c_client *stdp4028_i2c) +{ + ge_b850v3_lvds_remove(); +} + +static const struct i2c_device_id stdp4028_ge_b850v3_fw_i2c_table[] = { + { "stdp4028_ge_fw" }, + {} +}; +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, + }, +}; + +static int stdp2690_ge_b850v3_fw_probe(struct i2c_client *stdp2690_i2c) +{ + struct device *dev = &stdp2690_i2c->dev; + int ret; + + ret = ge_b850v3_lvds_init(dev); + + if (ret) + return ret; + + ge_b850v3_lvds_ptr->stdp2690_i2c = stdp2690_i2c; + i2c_set_clientdata(stdp2690_i2c, ge_b850v3_lvds_ptr); + + /* Only register after both bridges are probed */ + if (!ge_b850v3_lvds_ptr->stdp4028_i2c) + return 0; + + return ge_b850v3_register(); +} + +static void stdp2690_ge_b850v3_fw_remove(struct i2c_client *stdp2690_i2c) +{ + ge_b850v3_lvds_remove(); +} + +static const struct i2c_device_id stdp2690_ge_b850v3_fw_i2c_table[] = { + { "stdp2690_ge_fw" }, + {} +}; +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, + }, +}; + +static int __init stdpxxxx_ge_b850v3_init(void) +{ + int ret; + + ret = i2c_add_driver(&stdp4028_ge_b850v3_fw_driver); + if (ret) + return ret; + + ret = i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); + if (ret) + i2c_del_driver(&stdp4028_ge_b850v3_fw_driver); + + return ret; +} +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); + +MODULE_AUTHOR("Peter Senna Tschudin <peter.senna@collabora.com>"); +MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk>"); +MODULE_DESCRIPTION("GE LVDS to DP++ display bridge)"); +MODULE_LICENSE("GPL v2"); |