437 lines
11 KiB
C
437 lines
11 KiB
C
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/*
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* Driver for MegaChips STDP4028 with GE B850v3 firmware (LVDS-DP)
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* Driver for MegaChips STDP2690 with GE B850v3 firmware (DP-DP++)
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* Copyright (c) 2017, Collabora Ltd.
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* Copyright (c) 2017, General Electric Company
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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* This driver creates a drm_bridge and a drm_connector for the LVDS to DP++
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* display bridge of the GE B850v3. There are two physical bridges on the video
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* signal pipeline: a STDP4028(LVDS to DP) and a STDP2690(DP to DP++). The
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* physical bridges are automatically configured by the input video signal, and
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* the driver has no access to the video processing pipeline. The driver is
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* only needed to read EDID from the STDP2690 and to handle HPD events from the
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* STDP4028. The driver communicates with both bridges over i2c. The video
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* signal pipeline is as follows:
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*
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* Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output
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*
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*/
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <drm/drm_atomic.h>
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#include <drm/drm_atomic_helper.h>
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#include <drm/drm_crtc_helper.h>
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#include <drm/drm_edid.h>
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#include <drm/drmP.h>
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#define EDID_EXT_BLOCK_CNT 0x7E
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#define STDP4028_IRQ_OUT_CONF_REG 0x02
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#define STDP4028_DPTX_IRQ_EN_REG 0x3C
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#define STDP4028_DPTX_IRQ_STS_REG 0x3D
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#define STDP4028_DPTX_STS_REG 0x3E
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#define STDP4028_DPTX_DP_IRQ_EN 0x1000
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#define STDP4028_DPTX_HOTPLUG_IRQ_EN 0x0400
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#define STDP4028_DPTX_LINK_CH_IRQ_EN 0x2000
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#define STDP4028_DPTX_IRQ_CONFIG \
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(STDP4028_DPTX_LINK_CH_IRQ_EN | STDP4028_DPTX_HOTPLUG_IRQ_EN)
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#define STDP4028_DPTX_HOTPLUG_STS 0x0200
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#define STDP4028_DPTX_LINK_STS 0x1000
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#define STDP4028_CON_STATE_CONNECTED \
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(STDP4028_DPTX_HOTPLUG_STS | STDP4028_DPTX_LINK_STS)
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#define STDP4028_DPTX_HOTPLUG_CH_STS 0x0400
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#define STDP4028_DPTX_LINK_CH_STS 0x2000
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#define STDP4028_DPTX_IRQ_CLEAR \
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(STDP4028_DPTX_LINK_CH_STS | STDP4028_DPTX_HOTPLUG_CH_STS)
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static DEFINE_MUTEX(ge_b850v3_lvds_dev_mutex);
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struct ge_b850v3_lvds {
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struct drm_connector connector;
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struct drm_bridge bridge;
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struct i2c_client *stdp4028_i2c;
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struct i2c_client *stdp2690_i2c;
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struct edid *edid;
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};
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static struct ge_b850v3_lvds *ge_b850v3_lvds_ptr;
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static u8 *stdp2690_get_edid(struct i2c_client *client)
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{
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struct i2c_adapter *adapter = client->adapter;
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unsigned char start = 0x00;
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unsigned int total_size;
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u8 *block = kmalloc(EDID_LENGTH, GFP_KERNEL);
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = &start,
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}, {
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = EDID_LENGTH,
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.buf = block,
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}
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};
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if (!block)
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return NULL;
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if (i2c_transfer(adapter, msgs, 2) != 2) {
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DRM_ERROR("Unable to read EDID.\n");
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goto err;
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}
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if (!drm_edid_block_valid(block, 0, false, NULL)) {
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DRM_ERROR("Invalid EDID data\n");
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goto err;
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}
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total_size = (block[EDID_EXT_BLOCK_CNT] + 1) * EDID_LENGTH;
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if (total_size > EDID_LENGTH) {
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kfree(block);
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block = kmalloc(total_size, GFP_KERNEL);
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if (!block)
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return NULL;
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/* Yes, read the entire buffer, and do not skip the first
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* EDID_LENGTH bytes.
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*/
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start = 0x00;
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msgs[1].len = total_size;
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msgs[1].buf = block;
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if (i2c_transfer(adapter, msgs, 2) != 2) {
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DRM_ERROR("Unable to read EDID extension blocks.\n");
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goto err;
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}
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if (!drm_edid_block_valid(block, 1, false, NULL)) {
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DRM_ERROR("Invalid EDID data\n");
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goto err;
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}
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}
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return block;
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err:
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kfree(block);
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return NULL;
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}
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static int ge_b850v3_lvds_get_modes(struct drm_connector *connector)
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{
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struct i2c_client *client;
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int num_modes = 0;
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client = ge_b850v3_lvds_ptr->stdp2690_i2c;
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kfree(ge_b850v3_lvds_ptr->edid);
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ge_b850v3_lvds_ptr->edid = (struct edid *)stdp2690_get_edid(client);
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if (ge_b850v3_lvds_ptr->edid) {
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drm_connector_update_edid_property(connector,
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ge_b850v3_lvds_ptr->edid);
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num_modes = drm_add_edid_modes(connector,
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ge_b850v3_lvds_ptr->edid);
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}
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return num_modes;
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}
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static enum drm_mode_status ge_b850v3_lvds_mode_valid(
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struct drm_connector *connector, struct drm_display_mode *mode)
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{
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return MODE_OK;
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}
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static const struct
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drm_connector_helper_funcs ge_b850v3_lvds_connector_helper_funcs = {
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.get_modes = ge_b850v3_lvds_get_modes,
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.mode_valid = ge_b850v3_lvds_mode_valid,
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};
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static enum drm_connector_status ge_b850v3_lvds_detect(
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struct drm_connector *connector, bool force)
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{
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struct i2c_client *stdp4028_i2c =
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ge_b850v3_lvds_ptr->stdp4028_i2c;
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s32 link_state;
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link_state = i2c_smbus_read_word_data(stdp4028_i2c,
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STDP4028_DPTX_STS_REG);
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if (link_state == STDP4028_CON_STATE_CONNECTED)
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return connector_status_connected;
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if (link_state == 0)
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return connector_status_disconnected;
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return connector_status_unknown;
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}
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static const struct drm_connector_funcs ge_b850v3_lvds_connector_funcs = {
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.fill_modes = drm_helper_probe_single_connector_modes,
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.detect = ge_b850v3_lvds_detect,
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.destroy = drm_connector_cleanup,
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.reset = drm_atomic_helper_connector_reset,
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.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
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.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
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};
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static irqreturn_t ge_b850v3_lvds_irq_handler(int irq, void *dev_id)
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{
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struct i2c_client *stdp4028_i2c
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= ge_b850v3_lvds_ptr->stdp4028_i2c;
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i2c_smbus_write_word_data(stdp4028_i2c,
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STDP4028_DPTX_IRQ_STS_REG,
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STDP4028_DPTX_IRQ_CLEAR);
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if (ge_b850v3_lvds_ptr->connector.dev)
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drm_kms_helper_hotplug_event(ge_b850v3_lvds_ptr->connector.dev);
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return IRQ_HANDLED;
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}
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static int ge_b850v3_lvds_attach(struct drm_bridge *bridge)
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{
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struct drm_connector *connector = &ge_b850v3_lvds_ptr->connector;
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struct i2c_client *stdp4028_i2c
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= ge_b850v3_lvds_ptr->stdp4028_i2c;
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int ret;
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if (!bridge->encoder) {
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DRM_ERROR("Parent encoder object not found");
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return -ENODEV;
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}
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connector->polled = DRM_CONNECTOR_POLL_HPD;
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drm_connector_helper_add(connector,
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&ge_b850v3_lvds_connector_helper_funcs);
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ret = drm_connector_init(bridge->dev, connector,
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&ge_b850v3_lvds_connector_funcs,
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DRM_MODE_CONNECTOR_DisplayPort);
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if (ret) {
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DRM_ERROR("Failed to initialize connector with drm\n");
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return ret;
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}
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ret = drm_connector_attach_encoder(connector, bridge->encoder);
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if (ret)
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return ret;
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/* Configures the bridge to re-enable interrupts after each ack. */
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i2c_smbus_write_word_data(stdp4028_i2c,
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STDP4028_IRQ_OUT_CONF_REG,
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STDP4028_DPTX_DP_IRQ_EN);
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/* Enable interrupts */
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i2c_smbus_write_word_data(stdp4028_i2c,
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STDP4028_DPTX_IRQ_EN_REG,
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STDP4028_DPTX_IRQ_CONFIG);
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return 0;
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}
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static const struct drm_bridge_funcs ge_b850v3_lvds_funcs = {
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.attach = ge_b850v3_lvds_attach,
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};
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static int ge_b850v3_lvds_init(struct device *dev)
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{
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mutex_lock(&ge_b850v3_lvds_dev_mutex);
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if (ge_b850v3_lvds_ptr)
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goto success;
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ge_b850v3_lvds_ptr = devm_kzalloc(dev,
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sizeof(*ge_b850v3_lvds_ptr),
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GFP_KERNEL);
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if (!ge_b850v3_lvds_ptr) {
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mutex_unlock(&ge_b850v3_lvds_dev_mutex);
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return -ENOMEM;
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}
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success:
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mutex_unlock(&ge_b850v3_lvds_dev_mutex);
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return 0;
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}
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static void ge_b850v3_lvds_remove(void)
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{
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mutex_lock(&ge_b850v3_lvds_dev_mutex);
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/*
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* This check is to avoid both the drivers
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* removing the bridge in their remove() function
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*/
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if (!ge_b850v3_lvds_ptr)
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goto out;
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drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge);
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kfree(ge_b850v3_lvds_ptr->edid);
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ge_b850v3_lvds_ptr = NULL;
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out:
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mutex_unlock(&ge_b850v3_lvds_dev_mutex);
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}
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static int stdp4028_ge_b850v3_fw_probe(struct i2c_client *stdp4028_i2c,
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const struct i2c_device_id *id)
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{
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struct device *dev = &stdp4028_i2c->dev;
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int ret;
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ret = ge_b850v3_lvds_init(dev);
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if (ret)
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return ret;
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ge_b850v3_lvds_ptr->stdp4028_i2c = stdp4028_i2c;
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i2c_set_clientdata(stdp4028_i2c, ge_b850v3_lvds_ptr);
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/* drm bridge initialization */
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ge_b850v3_lvds_ptr->bridge.funcs = &ge_b850v3_lvds_funcs;
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ge_b850v3_lvds_ptr->bridge.of_node = dev->of_node;
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drm_bridge_add(&ge_b850v3_lvds_ptr->bridge);
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/* Clear pending interrupts since power up. */
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i2c_smbus_write_word_data(stdp4028_i2c,
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STDP4028_DPTX_IRQ_STS_REG,
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STDP4028_DPTX_IRQ_CLEAR);
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if (!stdp4028_i2c->irq)
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return 0;
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return devm_request_threaded_irq(&stdp4028_i2c->dev,
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stdp4028_i2c->irq, NULL,
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ge_b850v3_lvds_irq_handler,
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IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
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"ge-b850v3-lvds-dp", ge_b850v3_lvds_ptr);
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}
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static int stdp4028_ge_b850v3_fw_remove(struct i2c_client *stdp4028_i2c)
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{
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ge_b850v3_lvds_remove();
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return 0;
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}
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static const struct i2c_device_id stdp4028_ge_b850v3_fw_i2c_table[] = {
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{"stdp4028_ge_fw", 0},
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{},
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};
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MODULE_DEVICE_TABLE(i2c, stdp4028_ge_b850v3_fw_i2c_table);
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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;
|
||
|
|
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);
|
||
|
|
|
||
|
|
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");
|