On Fri, Oct 13, 2017 at 04:11:43PM +0530, Meghana Madhyastha wrote:
Rename tinydrm_of_find_backlight to backlight_get and move it
to linux/backlight.c so that it can be used by other drivers.
[apologies if this has been brought up in previous versions, I haven't been
following closely]
I don't think "backlight_get" is a good name for this function. How about
of_find_backlight_by_name (since there's already of_find_backlight_by_node)?
Signed-off-by: Meghana Madhyastha <meghana.madhyastha@xxxxxxxxx>
---
Changes in v13:
-Add backlight_put to backlight.h in this patch
drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 40 --------------------------
drivers/gpu/drm/tinydrm/mi0283qt.c | 3 +-
drivers/video/backlight/backlight.c | 37 ++++++++++++++++++++++++
include/drm/tinydrm/tinydrm-helpers.h | 2 --
include/linux/backlight.h | 19 ++++++++++++
5 files changed, 58 insertions(+), 43 deletions(-)
diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
index a42dee6..cb1a01a 100644
--- a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
@@ -236,46 +236,6 @@ void tinydrm_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
}
EXPORT_SYMBOL(tinydrm_xrgb8888_to_gray8);
-/**
- * tinydrm_of_find_backlight - Find backlight device in device-tree
- * @dev: Device
- *
- * This function looks for a DT node pointed to by a property named 'backlight'
- * and uses of_find_backlight_by_node() to get the backlight device.
- * Additionally if the brightness property is zero, it is set to
- * max_brightness.
- *
- * Returns:
- * NULL if there's no backlight property.
- * Error pointer -EPROBE_DEFER if the DT node is found, but no backlight device
- * is found.
- * If the backlight device is found, a pointer to the structure is returned.
- */
-struct backlight_device *tinydrm_of_find_backlight(struct device *dev)
-{
- struct backlight_device *backlight;
- struct device_node *np;
-
- np = of_parse_phandle(dev->of_node, "backlight", 0);
- if (!np)
- return NULL;
-
- backlight = of_find_backlight_by_node(np);
- of_node_put(np);
-
- if (!backlight)
- return ERR_PTR(-EPROBE_DEFER);
-
- if (!backlight->props.brightness) {
- backlight->props.brightness = backlight->props.max_brightness;
- DRM_DEBUG_KMS("Backlight brightness set to %d\n",
- backlight->props.brightness);
- }
-
- return backlight;
-}
-EXPORT_SYMBOL(tinydrm_of_find_backlight);
-
#if IS_ENABLED(CONFIG_SPI)
/**
diff --git a/drivers/gpu/drm/tinydrm/mi0283qt.c b/drivers/gpu/drm/tinydrm/mi0283qt.c
index 7fd2691..a932185 100644
--- a/drivers/gpu/drm/tinydrm/mi0283qt.c
+++ b/drivers/gpu/drm/tinydrm/mi0283qt.c
@@ -12,6 +12,7 @@
#include <drm/tinydrm/ili9341.h>
#include <drm/tinydrm/mipi-dbi.h>
#include <drm/tinydrm/tinydrm-helpers.h>
+#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
@@ -188,7 +189,7 @@ static int mi0283qt_probe(struct spi_device *spi)
if (IS_ERR(mipi->regulator))
return PTR_ERR(mipi->regulator);
- mipi->backlight = tinydrm_of_find_backlight(dev);
+ mipi->backlight = backlight_get(dev);
if (IS_ERR(mipi->backlight))
return PTR_ERR(mipi->backlight);
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 8049e76..c4e94d0 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -580,6 +580,43 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node)
EXPORT_SYMBOL(of_find_backlight_by_node);
#endif
+/**
+ * backlight_get - Get backlight device
+ * @dev: Device
+ *
+ * This function looks for a property named 'backlight' on the DT node
+ * connected to @dev and looks up the backlight device.
+ *
+ * Call backlight_put() to drop the reference on the backlight device.
+ *
+ * Returns:
+ * A pointer to the backlight device if found.
+ * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight
+ * device is found.
+ * NULL if there's no backlight property.
+ */
+struct backlight_device *backlight_get(struct device *dev)
+{
+ struct backlight_device *bd = NULL;
+ struct device_node *np;
+
+ if (!dev)
+ return NULL;
+
+ if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
I'm not really used to seeing IS_ENABLED(CONFIG_BLAH) inline. The common
patterns seems to be wrapping the actual implementation in #if
IS_ENABLED(CONFIG_BLAH) and then sticking a stub implementation in the #else.
I see below that you already have a stub if backlight is not enabled, so expand
that #if to include CONFIG_OF as well.
+ np = of_parse_phandle(dev->of_node, "backlight", 0);
+ if (np) {
+ bd = of_find_backlight_by_node(np);
+ of_node_put(np);
+ if (!bd)
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+ }
+
+ return bd;
+}
+EXPORT_SYMBOL(backlight_get);
+
static void __exit backlight_class_exit(void)
{
class_destroy(backlight_class);
diff --git a/include/drm/tinydrm/tinydrm-helpers.h b/include/drm/tinydrm/tinydrm-helpers.h
index f54fae0..0a4ddbc 100644
--- a/include/drm/tinydrm/tinydrm-helpers.h
+++ b/include/drm/tinydrm/tinydrm-helpers.h
@@ -46,8 +46,6 @@ void tinydrm_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
void tinydrm_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
struct drm_clip_rect *clip);
-struct backlight_device *tinydrm_of_find_backlight(struct device *dev);
-
size_t tinydrm_spi_max_transfer_size(struct spi_device *spi, size_t max_len);
bool tinydrm_spi_bpw_supported(struct spi_device *spi, u8 bpw);
int tinydrm_spi_transfer(struct spi_device *spi, u32 speed_hz,
diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index b88fabb..987a6d7 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -159,6 +159,16 @@ static inline int backlight_disable(struct backlight_device *bd)
return backlight_update_status(bd);
}
+/**
+ * backlight_put - Drop backlight reference
+ * @bd: the backlight device to put
+ */
+static inline void backlight_put(struct backlight_device *bd)
+{
+ if (bd)
+ put_device(&bd->dev);
+}
I'm not convinced this function needs to exist.
+
extern struct backlight_device *backlight_device_register(const char *name,
struct device *dev, void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props);
@@ -202,4 +212,13 @@ of_find_backlight_by_node(struct device_node *node)
}
#endif
+#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
+struct backlight_device *backlight_get(struct device *dev);
+#else
+static inline struct backlight_device *backlight_get(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
#endif
--
2.7.4
--
You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@xxxxxxxxxxxxxxxx.
To post to this group, send email to outreachy-kernel@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/e2ef05bf46438427d08c6a61fe5058156800db95.1507890285.git.meghana.madhyastha%40gmail.com.
For more options, visit https://groups.google.com/d/optout.
