--- /dev/null
+/*
+ * 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;
+
+static 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,
+ },
+};
+
+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,
+ },
+};
+
+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);
+
+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");
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff