[PATCH v3 13/56] drm/omap: dsi: introduce mipi_dsi_host

Tomi Valkeinen
2020-11-05T12:04:42Z

From: Sebastian Reichel <sebastian.reichel@collabora.com>

This moves from custom platform driver infrastructure to mipi_dsi_host
and mipi_dsi_device. Note, that this is a graduate step and the driver
only uses the devices types and transfer function, but not yet the new
device binding style or drm_panel.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
.../gpu/drm/omapdrm/displays/panel-dsi-cm.c | 121 +++++++++---------
drivers/gpu/drm/omapdrm/dss/dsi.c | 54 ++++++--
drivers/gpu/drm/omapdrm/dss/omapdss.h | 4 -
3 files changed, 103 insertions(+), 76 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
index ea76a89d1833..c3190223d192 100644
--- a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
+++ b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
@@ -14,7 +14,6 @@
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/module.h>
-#include <linux/platform_device.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
@@ -39,13 +38,13 @@
#define DCS_GET_ID3 0xdc

struct panel_drv_data {
+ struct mipi_dsi_device *dsi;
+
struct omap_dss_device dssdev;
struct omap_dss_device *src;

struct videomode vm;

- struct platform_device *pdev;
-
struct mutex lock;

struct backlight_device *bldev;
@@ -139,7 +138,7 @@ static void hw_guard_wait(struct panel_drv_data *ddata)

static int dsicm_dcs_read_1(struct panel_drv_data *ddata, u8 dcs_cmd, u8 *data)
{
- struct omap_dss_device *src = ddata->src;
+ struct mipi_dsi_device *dsi = ddata->dsi;
const struct mipi_dsi_msg msg = {
.channel = ddata->channel,
.type = MIPI_DSI_DCS_READ,
@@ -149,12 +148,12 @@ static int dsicm_dcs_read_1(struct panel_drv_data *ddata, u8 dcs_cmd, u8 *data)
.rx_buf = data
};

- return src->ops->dsi.transfer(src, &msg);
+ return dsi->host->ops->transfer(dsi->host, &msg);
}

static int dsicm_dcs_write_0(struct panel_drv_data *ddata, u8 dcs_cmd)
{
- struct omap_dss_device *src = ddata->src;
+ struct mipi_dsi_device *dsi = ddata->dsi;
const struct mipi_dsi_msg msg = {
.channel = ddata->channel,
.type = MIPI_DSI_DCS_SHORT_WRITE,
@@ -162,12 +161,12 @@ static int dsicm_dcs_write_0(struct panel_drv_data *ddata, u8 dcs_cmd)
.tx_len = 1,
};

- return src->ops->dsi.transfer(src, &msg);
+ return dsi->host->ops->transfer(dsi->host, &msg);
}

static int dsicm_dcs_write_1(struct panel_drv_data *ddata, u8 dcs_cmd, u8 param)
{
- struct omap_dss_device *src = ddata->src;
+ struct mipi_dsi_device *dsi = ddata->dsi;
const u8 buf[] = { dcs_cmd, param };
const struct mipi_dsi_msg msg = {
.channel = ddata->channel,
@@ -176,13 +175,13 @@ static int dsicm_dcs_write_1(struct panel_drv_data *ddata, u8 dcs_cmd, u8 param)
.tx_len = 2,
};

- return src->ops->dsi.transfer(src, &msg);
+ return dsi->host->ops->transfer(dsi->host, &msg);
}

static int dsicm_sleep_in(struct panel_drv_data *ddata)

{
- struct omap_dss_device *src = ddata->src;
+ struct mipi_dsi_device *dsi = ddata->dsi;
int r;
const u8 cmd = MIPI_DCS_ENTER_SLEEP_MODE;
const struct mipi_dsi_msg msg = {
@@ -194,7 +193,7 @@ static int dsicm_sleep_in(struct panel_drv_data *ddata)

hw_guard_wait(ddata);

- r = src->ops->dsi.transfer(src, &msg);
+ r = dsi->host->ops->transfer(dsi->host, &msg);
if (r)
return r;

@@ -242,7 +241,7 @@ static int dsicm_get_id(struct panel_drv_data *ddata, u8 *id1, u8 *id2, u8 *id3)
static int dsicm_set_update_window(struct panel_drv_data *ddata,
u16 x, u16 y, u16 w, u16 h)
{
- struct omap_dss_device *src = ddata->src;
+ struct mipi_dsi_device *dsi = ddata->dsi;
int r;
u16 x1 = x;
u16 x2 = x + w - 1;
@@ -279,11 +278,11 @@ static int dsicm_set_update_window(struct panel_drv_data *ddata,
.tx_len = 5,
};

- r = src->ops->dsi.transfer(src, &msgX);
+ r = dsi->host->ops->transfer(dsi->host, &msgX);
if (r)
return r;

- r = src->ops->dsi.transfer(src, &msgY);
+ r = dsi->host->ops->transfer(dsi->host, &msgY);
if (r)
return r;

@@ -326,7 +325,7 @@ static int dsicm_enter_ulps(struct panel_drv_data *ddata)
return 0;

err:
- dev_err(&ddata->pdev->dev, "enter ULPS failed");
+ dev_err(&ddata->dsi->dev, "enter ULPS failed");
dsicm_panel_reset(ddata);

ddata->ulps_enabled = false;
@@ -349,7 +348,7 @@ static int dsicm_exit_ulps(struct panel_drv_data *ddata)

r = _dsicm_enable_te(ddata, true);
if (r) {
- dev_err(&ddata->pdev->dev, "failed to re-enable TE");
+ dev_err(&ddata->dsi->dev, "failed to re-enable TE");
goto err2;
}

@@ -363,7 +362,7 @@ static int dsicm_exit_ulps(struct panel_drv_data *ddata)
return 0;

err2:
- dev_err(&ddata->pdev->dev, "failed to exit ULPS");
+ dev_err(&ddata->dsi->dev, "failed to exit ULPS");

r = dsicm_panel_reset(ddata);
if (!r) {
@@ -400,7 +399,7 @@ static int dsicm_bl_update_status(struct backlight_device *dev)
else
level = 0;

- dev_dbg(&ddata->pdev->dev, "update brightness to %d\n", level);
+ dev_dbg(&ddata->dsi->dev, "update brightness to %d\n", level);

mutex_lock(&ddata->lock);

@@ -637,7 +636,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata)
if (ddata->vpnl) {
r = regulator_enable(ddata->vpnl);
if (r) {
- dev_err(&ddata->pdev->dev,
+ dev_err(&ddata->dsi->dev,
"failed to enable VPNL: %d\n", r);
return r;
}
@@ -646,7 +645,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata)
if (ddata->vddi) {
r = regulator_enable(ddata->vddi);
if (r) {
- dev_err(&ddata->pdev->dev,
+ dev_err(&ddata->dsi->dev,
"failed to enable VDDI: %d\n", r);
goto err_vpnl;
}
@@ -654,7 +653,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata)

r = src->ops->dsi.set_config(src, &dsi_config);
if (r) {
- dev_err(&ddata->pdev->dev, "failed to configure DSI\n");
+ dev_err(&ddata->dsi->dev, "failed to configure DSI\n");
goto err_vddi;
}

@@ -701,7 +700,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata)
ddata->enabled = true;

if (!ddata->intro_printed) {
- dev_info(&ddata->pdev->dev, "panel revision %02x.%02x.%02x\n",
+ dev_info(&ddata->dsi->dev, "panel revision %02x.%02x.%02x\n",
id1, id2, id3);
ddata->intro_printed = true;
}
@@ -710,7 +709,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata)

return 0;
err:
- dev_err(&ddata->pdev->dev, "error while enabling panel, issuing HW reset\n");
+ dev_err(&ddata->dsi->dev, "error while enabling panel, issuing HW reset\n");

dsicm_hw_reset(ddata);

@@ -737,7 +736,7 @@ static void dsicm_power_off(struct panel_drv_data *ddata)
r = dsicm_sleep_in(ddata);

if (r) {
- dev_err(&ddata->pdev->dev,
+ dev_err(&ddata->dsi->dev,
"error disabling panel, issuing HW reset\n");
dsicm_hw_reset(ddata);
}
@@ -754,7 +753,7 @@ static void dsicm_power_off(struct panel_drv_data *ddata)

static int dsicm_panel_reset(struct panel_drv_data *ddata)
{
- dev_err(&ddata->pdev->dev, "performing LCD reset\n");
+ dev_err(&ddata->dsi->dev, "performing LCD reset\n");

dsicm_power_off(ddata);
dsicm_hw_reset(ddata);
@@ -765,7 +764,7 @@ static int dsicm_connect(struct omap_dss_device *src,
struct omap_dss_device *dst)
{
struct panel_drv_data *ddata = to_panel_data(dst);
- struct device *dev = &ddata->pdev->dev;
+ struct device *dev = &ddata->dsi->dev;
int r;

r = src->ops->dsi.request_vc(src, ddata->channel);
@@ -810,7 +809,7 @@ static void dsicm_enable(struct omap_dss_device *dssdev)

return;
err:
- dev_dbg(&ddata->pdev->dev, "enable failed (%d)\n", r);
+ dev_dbg(&ddata->dsi->dev, "enable failed (%d)\n", r);
mutex_unlock(&ddata->lock);
}

@@ -842,7 +841,7 @@ static void dsicm_framedone_cb(int err, void *data)
struct panel_drv_data *ddata = data;
struct omap_dss_device *src = ddata->src;

- dev_dbg(&ddata->pdev->dev, "framedone, err %d\n", err);
+ dev_dbg(&ddata->dsi->dev, "framedone, err %d\n", err);
src->ops->dsi.bus_unlock(src);
}

@@ -866,7 +865,7 @@ static irqreturn_t dsicm_te_isr(int irq, void *data)

return IRQ_HANDLED;
err:
- dev_err(&ddata->pdev->dev, "start update failed\n");
+ dev_err(&ddata->dsi->dev, "start update failed\n");
src->ops->dsi.bus_unlock(src);
return IRQ_HANDLED;
}
@@ -877,7 +876,7 @@ static void dsicm_te_timeout_work_callback(struct work_struct *work)
te_timeout_work.work);
struct omap_dss_device *src = ddata->src;

- dev_err(&ddata->pdev->dev, "TE not received for 250ms!\n");
+ dev_err(&ddata->dsi->dev, "TE not received for 250ms!\n");

atomic_set(&ddata->do_update, 0);
src->ops->dsi.bus_unlock(src);
@@ -890,7 +889,7 @@ static int dsicm_update(struct omap_dss_device *dssdev,
struct omap_dss_device *src = ddata->src;
int r;

- dev_dbg(&ddata->pdev->dev, "update %d, %d, %d x %d\n", x, y, w, h);
+ dev_dbg(&ddata->dsi->dev, "update %d, %d, %d x %d\n", x, y, w, h);

mutex_lock(&ddata->lock);
src->ops->dsi.bus_lock(src);
@@ -935,14 +934,14 @@ static int dsicm_sync(struct omap_dss_device *dssdev)
struct panel_drv_data *ddata = to_panel_data(dssdev);
struct omap_dss_device *src = ddata->src;

- dev_dbg(&ddata->pdev->dev, "sync\n");
+ dev_dbg(&ddata->dsi->dev, "sync\n");

mutex_lock(&ddata->lock);
src->ops->dsi.bus_lock(src);
src->ops->dsi.bus_unlock(src);
mutex_unlock(&ddata->lock);

- dev_dbg(&ddata->pdev->dev, "sync done\n");
+ dev_dbg(&ddata->dsi->dev, "sync done\n");

return 0;
}
@@ -1019,7 +1018,7 @@ static int dsicm_set_max_rx_packet_size(struct omap_dss_device *dssdev,
u16 size)
{
struct panel_drv_data *ddata = to_panel_data(dssdev);
- struct omap_dss_device *src = ddata->src;
+ struct mipi_dsi_device *dsi = ddata->dsi;

const u8 buf[] = {
size & 0xff,
@@ -1033,7 +1032,7 @@ static int dsicm_set_max_rx_packet_size(struct omap_dss_device *dssdev,
.tx_len = 2,
};

- return src->ops->dsi.transfer(src, &msg);
+ return dsi->host->ops->transfer(dsi->host, &msg);
}

static int dsicm_memory_read(struct omap_dss_device *dssdev,
@@ -1041,6 +1040,7 @@ static int dsicm_memory_read(struct omap_dss_device *dssdev,
u16 x, u16 y, u16 w, u16 h)
{
struct panel_drv_data *ddata = to_panel_data(dssdev);
+ struct mipi_dsi_device *dsi = ddata->dsi;
struct omap_dss_device *src = ddata->src;
int r;
int first = 1;
@@ -1092,7 +1092,7 @@ static int dsicm_memory_read(struct omap_dss_device *dssdev,
};
first = 0;

- r = src->ops->dsi.transfer(src, &msg);
+ r = dsi->host->ops->transfer(dsi->host, &msg);
if (r < 0) {
dev_err(dssdev->dev, "read error\n");
goto err3;
@@ -1101,12 +1101,12 @@ static int dsicm_memory_read(struct omap_dss_device *dssdev,
buf_used += r;

if (r < plen) {
- dev_err(&ddata->pdev->dev, "short read\n");
+ dev_err(&ddata->dsi->dev, "short read\n");
break;
}

if (signal_pending(current)) {
- dev_err(&ddata->pdev->dev, "signal pending, "
+ dev_err(&ddata->dsi->dev, "signal pending, "
"aborting memory read\n");
r = -ERESTARTSYS;
goto err3;
@@ -1200,28 +1200,28 @@ static const struct omap_dss_driver dsicm_dss_driver = {
.memory_read = dsicm_memory_read,
};

-static int dsicm_probe_of(struct platform_device *pdev)
+static int dsicm_probe_of(struct mipi_dsi_device *dsi)
{
- struct device_node *node = pdev->dev.of_node;
+ struct device_node *node = dsi->dev.of_node;
struct backlight_device *backlight;
- struct panel_drv_data *ddata = platform_get_drvdata(pdev);
+ struct panel_drv_data *ddata = mipi_dsi_get_drvdata(dsi);
struct display_timing timing;
int err;

ddata->channel = TCH;

- ddata->reset_gpio = devm_gpiod_get(&pdev->dev, "reset", GPIOD_OUT_LOW);
+ ddata->reset_gpio = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(ddata->reset_gpio)) {
err = PTR_ERR(ddata->reset_gpio);
- dev_err(&pdev->dev, "reset gpio request failed: %d", err);
+ dev_err(&dsi->dev, "reset gpio request failed: %d", err);
return err;
}

- ddata->ext_te_gpio = devm_gpiod_get_optional(&pdev->dev, "te",
+ ddata->ext_te_gpio = devm_gpiod_get_optional(&dsi->dev, "te",
GPIOD_IN);
if (IS_ERR(ddata->ext_te_gpio)) {
err = PTR_ERR(ddata->ext_te_gpio);
- dev_err(&pdev->dev, "TE gpio request failed: %d", err);
+ dev_err(&dsi->dev, "TE gpio request failed: %d", err);
return err;
}

@@ -1232,7 +1232,7 @@ static int dsicm_probe_of(struct platform_device *pdev)
ddata->vm.pixelclock =
ddata->vm.hactive * ddata->vm.vactive * 60;
} else {
- dev_warn(&pdev->dev,
+ dev_warn(&dsi->dev,
"failed to get video timing, using defaults\n");
}

@@ -1242,7 +1242,7 @@ static int dsicm_probe_of(struct platform_device *pdev)
ddata->height_mm = 0;
of_property_read_u32(node, "height-mm", &ddata->height_mm);

- ddata->vpnl = devm_regulator_get_optional(&pdev->dev, "vpnl");
+ ddata->vpnl = devm_regulator_get_optional(&dsi->dev, "vpnl");
if (IS_ERR(ddata->vpnl)) {
err = PTR_ERR(ddata->vpnl);
if (err == -EPROBE_DEFER)
@@ -1250,7 +1250,7 @@ static int dsicm_probe_of(struct platform_device *pdev)
ddata->vpnl = NULL;
}

- ddata->vddi = devm_regulator_get_optional(&pdev->dev, "vddi");
+ ddata->vddi = devm_regulator_get_optional(&dsi->dev, "vddi");
if (IS_ERR(ddata->vddi)) {
err = PTR_ERR(ddata->vddi);
if (err == -EPROBE_DEFER)
@@ -1258,7 +1258,7 @@ static int dsicm_probe_of(struct platform_device *pdev)
ddata->vddi = NULL;
}

- backlight = devm_of_find_backlight(&pdev->dev);
+ backlight = devm_of_find_backlight(&dsi->dev);
if (IS_ERR(backlight))
return PTR_ERR(backlight);

@@ -1273,11 +1273,11 @@ static int dsicm_probe_of(struct platform_device *pdev)
return 0;
}

-static int dsicm_probe(struct platform_device *pdev)
+static int dsicm_probe(struct mipi_dsi_device *dsi)
{
struct panel_drv_data *ddata;
struct backlight_device *bldev = NULL;
- struct device *dev = &pdev->dev;
+ struct device *dev = &dsi->dev;
struct omap_dss_device *dssdev;
int r;

@@ -1287,14 +1287,14 @@ static int dsicm_probe(struct platform_device *pdev)
if (!ddata)
return -ENOMEM;

- platform_set_drvdata(pdev, ddata);
- ddata->pdev = pdev;
+ mipi_dsi_set_drvdata(dsi, ddata);
+ ddata->dsi = dsi;

ddata->vm.hactive = 864;
ddata->vm.vactive = 480;
ddata->vm.pixelclock = 864 * 480 * 60;

- r = dsicm_probe_of(pdev);
+ r = dsicm_probe_of(dsi);
if (r)
return r;

@@ -1376,12 +1376,12 @@ static int dsicm_probe(struct platform_device *pdev)
return r;
}

-static int __exit dsicm_remove(struct platform_device *pdev)
+static int __exit dsicm_remove(struct mipi_dsi_device *dsi)
{
- struct panel_drv_data *ddata = platform_get_drvdata(pdev);
+ struct panel_drv_data *ddata = mipi_dsi_get_drvdata(dsi);
struct omap_dss_device *dssdev = &ddata->dssdev;

- dev_dbg(&pdev->dev, "remove\n");
+ dev_dbg(&dsi->dev, "remove\n");

omapdss_device_unregister(dssdev);

@@ -1389,7 +1389,7 @@ static int __exit dsicm_remove(struct platform_device *pdev)
dsicm_disable(dssdev);
omapdss_device_disconnect(ddata->src, dssdev);

- sysfs_remove_group(&pdev->dev.kobj, &dsicm_attr_group);
+ sysfs_remove_group(&dsi->dev.kobj, &dsicm_attr_group);

if (ddata->extbldev)
put_device(&ddata->extbldev->dev);
@@ -1410,7 +1410,7 @@ static const struct of_device_id dsicm_of_match[] = {

MODULE_DEVICE_TABLE(of, dsicm_of_match);

-static struct platform_driver dsicm_driver = {
+static struct mipi_dsi_driver dsicm_driver = {
.probe = dsicm_probe,
.remove = __exit_p(dsicm_remove),
.driver = {
@@ -1419,8 +1419,7 @@ static struct platform_driver dsicm_driver = {
.suppress_bind_attrs = true,
},
};
-
-module_platform_driver(dsicm_driver);
+module_mipi_dsi_driver(dsicm_driver);

MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
MODULE_DESCRIPTION("Generic DSI Command Mode Panel Driver");
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index 6fa7833e32ad..d1187a8af37f 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -334,6 +334,8 @@ struct dsi_data {
struct regmap *syscon;
struct dss_device *dss;

+ struct mipi_dsi_host host;
+
struct dispc_clock_info user_dispc_cinfo;
struct dss_pll_clock_info user_dsi_cinfo;

@@ -432,6 +434,11 @@ static inline struct dsi_data *to_dsi_data(struct omap_dss_device *dssdev)
return dev_get_drvdata(dssdev->dev);
}

+static inline struct dsi_data *host_to_omap(struct mipi_dsi_host *host)
+{
+ return container_of(host, struct dsi_data, host);
+}
+
static inline void dsi_write_reg(struct dsi_data *dsi,
const struct dsi_reg idx, u32 val)
{
@@ -4711,9 +4718,12 @@ static void dsi_release_vc(struct omap_dss_device *dssdev, int channel)
}
}

-static ssize_t omap_dsi_transfer(struct omap_dss_device *dssdev,
- const struct mipi_dsi_msg *msg)
+static ssize_t omap_dsi_host_transfer(struct mipi_dsi_host *host,
+ const struct mipi_dsi_msg *msg)
{
+ struct dsi_data *dsi = host_to_omap(host);
+ struct omap_dss_device *dssdev = &dsi->output;
+
switch (msg->type) {
case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
@@ -4787,11 +4797,30 @@ static const struct omap_dss_device_ops dsi_ops = {

.request_vc = dsi_request_vc,
.release_vc = dsi_release_vc,
-
- .transfer = omap_dsi_transfer,
},
};

+static int omap_dsi_host_attach(struct mipi_dsi_host *host,
+ struct mipi_dsi_device *dsi)
+{
+ /* TODO: convert driver from custom binding method to this one */
+ return 0;
+}
+
+static int omap_dsi_host_detach(struct mipi_dsi_host *host,
+ struct mipi_dsi_device *dsi)
+{
+ /* TODO: convert driver from custom binding method to this one */
+ return 0;
+}
+
+static const struct mipi_dsi_host_ops omap_dsi_host_ops = {
+ .attach = omap_dsi_host_attach,
+ .detach = omap_dsi_host_detach,
+ .transfer = omap_dsi_host_transfer,
+};
+
+
/* -----------------------------------------------------------------------------
* PLL
*/
@@ -5260,15 +5289,18 @@ static int dsi_probe(struct platform_device *pdev)
dsi->num_lanes_supported = 3;
}

- r = of_platform_populate(dev->of_node, NULL, NULL, dev);
- if (r) {
- DSSERR("Failed to populate DSI child devices: %d\n", r);
+ dsi->host.ops = &omap_dsi_host_ops;
+ dsi->host.dev = &pdev->dev;
+
+ r = mipi_dsi_host_register(&dsi->host);
+ if (r < 0) {
+ dev_err(&pdev->dev, "failed to register DSI host: %d\n", r);
goto err_pm_disable;
}

r = dsi_init_output(dsi);
if (r)
- goto err_of_depopulate;
+ goto err_dsi_host_unregister;

r = dsi_probe_of(dsi);
if (r) {
@@ -5284,8 +5316,8 @@ static int dsi_probe(struct platform_device *pdev)

err_uninit_output:
dsi_uninit_output(dsi);
-err_of_depopulate:
- of_platform_depopulate(dev);
+err_dsi_host_unregister:
+ mipi_dsi_host_unregister(&dsi->host);
err_pm_disable:
pm_runtime_disable(dev);
return r;
@@ -5299,7 +5331,7 @@ static int dsi_remove(struct platform_device *pdev)

dsi_uninit_output(dsi);

- of_platform_depopulate(&pdev->dev);
+ mipi_dsi_host_unregister(&dsi->host);

pm_runtime_disable(&pdev->dev);

diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index 40e1ce9e256e..8cd2c800922e 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -304,10 +304,6 @@ struct omapdss_dsi_ops {

int (*request_vc)(struct omap_dss_device *dssdev, int channel);
void (*release_vc)(struct omap_dss_device *dssdev, int channel);
-
- /* data transfer */
- ssize_t (*transfer)(struct omap_dss_device *dssdev,
- const struct mipi_dsi_msg *msg);
};

struct omap_dss_device_ops {