[RFC v2 1/5] drm/dsi: Refactor device creation

From: Archit Taneja
Date: Tue Oct 06 2015 - 05:26:22 EST


Simplify the mipi dsi device creation process. device_initialize and
device_add don't need to be called separately when creating
mipi_dsi_device's. Use device_register instead to simplify things.

Create a helper function mipi_dsi_device_new which takes in struct
mipi_dsi_device_info and mipi_dsi_host. It clubs the functions
mipi_dsi_device_alloc and mipi_dsi_device_add into one.

mipi_dsi_device_info acts as a template to populate the dsi device
information. This is populated by of_mipi_dsi_device_add and passed to
mipi_dsi_device_new.

Later on, we'll provide mipi_dsi_device_new as a standalone way to create
a dsi device not available via DT.

The new device creation process tries to closely follow what's been done
in i2c_new_device in i2c-core.

Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_mipi_dsi.c | 61 +++++++++++++++++-------------------------
include/drm/drm_mipi_dsi.h | 15 +++++++++++
2 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 2d5ca8ee..245ecfe 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -102,9 +102,18 @@ static const struct device_type mipi_dsi_device_type = {
.release = mipi_dsi_dev_release,
};

-static struct mipi_dsi_device *mipi_dsi_device_alloc(struct mipi_dsi_host *host)
+struct mipi_dsi_device *mipi_dsi_device_new(struct mipi_dsi_host *host,
+ struct mipi_dsi_device_info *info)
{
struct mipi_dsi_device *dsi;
+ struct device *dev = host->dev;
+ int r;
+
+ if (info->reg > 3) {
+ dev_err(dev, "device node has invalid reg property: %u\n",
+ info->reg);
+ return ERR_PTR(-EINVAL);
+ }

dsi = kzalloc(sizeof(*dsi), GFP_KERNEL);
if (!dsi)
@@ -114,26 +123,27 @@ static struct mipi_dsi_device *mipi_dsi_device_alloc(struct mipi_dsi_host *host)
dsi->dev.bus = &mipi_dsi_bus_type;
dsi->dev.parent = host->dev;
dsi->dev.type = &mipi_dsi_device_type;
+ dsi->dev.of_node = info->node;
+ dsi->channel = info->reg;

- device_initialize(&dsi->dev);
-
- return dsi;
-}
-
-static int mipi_dsi_device_add(struct mipi_dsi_device *dsi)
-{
- struct mipi_dsi_host *host = dsi->host;
+ dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev), info->reg);

- dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev), dsi->channel);
+ r = device_register(&dsi->dev);
+ if (r) {
+ dev_err(dev, "failed to register device: %d\n", r);
+ kfree(dsi);
+ return ERR_PTR(r);
+ }

- return device_add(&dsi->dev);
+ return dsi;
}
+EXPORT_SYMBOL(mipi_dsi_device_new);

static struct mipi_dsi_device *
of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
{
- struct mipi_dsi_device *dsi;
struct device *dev = host->dev;
+ struct mipi_dsi_device_info info = { };
int ret;
u32 reg;

@@ -144,31 +154,10 @@ of_mipi_dsi_device_add(struct mipi_dsi_host *host, struct device_node *node)
return ERR_PTR(-EINVAL);
}

- if (reg > 3) {
- dev_err(dev, "device node %s has invalid reg property: %u\n",
- node->full_name, reg);
- return ERR_PTR(-EINVAL);
- }
-
- dsi = mipi_dsi_device_alloc(host);
- if (IS_ERR(dsi)) {
- dev_err(dev, "failed to allocate DSI device %s: %ld\n",
- node->full_name, PTR_ERR(dsi));
- return dsi;
- }
-
- dsi->dev.of_node = of_node_get(node);
- dsi->channel = reg;
+ info.reg = reg;
+ info.node = of_node_get(node);

- ret = mipi_dsi_device_add(dsi);
- if (ret) {
- dev_err(dev, "failed to add DSI device %s: %d\n",
- node->full_name, ret);
- kfree(dsi);
- return ERR_PTR(ret);
- }
-
- return dsi;
+ return mipi_dsi_device_new(host, &info);
}

int mipi_dsi_host_register(struct mipi_dsi_host *host)
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index f1d8d0d..90f4f3c 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -140,6 +140,19 @@ enum mipi_dsi_pixel_format {
};

/**
+ * struct mipi_dsi_device_info - template for creating a mipi_dsi_device
+ * @reg: DSI virtual channel assigned to peripheral
+ * @node: pointer to OF device node
+ *
+ * This is populated and passed to mipi_dsi_device_new to create a new
+ * DSI device
+ */
+struct mipi_dsi_device_info {
+ u32 reg;
+ struct device_node *node;
+};
+
+/**
* struct mipi_dsi_device - DSI peripheral device
* @host: DSI host for this peripheral
* @dev: driver model device node for this peripheral
@@ -174,6 +187,8 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
size_t num_params, void *data, size_t size);

+struct mipi_dsi_device *mipi_dsi_device_new(struct mipi_dsi_host *host,
+ struct mipi_dsi_device_info *info);
/**
* enum mipi_dsi_dcs_tear_mode - Tearing Effect Output Line mode
* @MIPI_DSI_DCS_TEAR_MODE_VBLANK: the TE output line consists of V-Blanking
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/