[PATCH v4 3/5] backlight: lm3533: Support initialization from Device Tree

From: Bjorn Andersson
Date: Mon Dec 26 2016 - 21:12:00 EST


From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>

Implement support for initialization of the lm3533 backlight from Device
Tree.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

This patch only depends on the acceptance of the DT binding (doesn't have to be
merged together with the mfd patch).

Changes since v3:
- Moved backlight DT parsing from mfd driver
- Gave driver its own compatible

drivers/video/backlight/lm3533_bl.c | 98 +++++++++++++++++++++++++++++++++++--
1 file changed, 95 insertions(+), 3 deletions(-)

diff --git a/drivers/video/backlight/lm3533_bl.c b/drivers/video/backlight/lm3533_bl.c
index 0e2337f367b6..2f132199e604 100644
--- a/drivers/video/backlight/lm3533_bl.c
+++ b/drivers/video/backlight/lm3533_bl.c
@@ -22,6 +22,7 @@


#define LM3533_HVCTRLBANK_COUNT 2
+#define LM3533_BL_DEFAULT_BRIGHTNESS 200
#define LM3533_BL_MAX_BRIGHTNESS 255

#define LM3533_REG_CTRLBANK_AB_BCONF 0x1a
@@ -269,6 +270,86 @@ static int lm3533_bl_setup(struct lm3533_bl *bl,
return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
}

+static int lm3533_of_parse_pwm_zones(struct device_node *node)
+{
+ const char *propname = "ti,pwm-zones";
+ u32 zones[5];
+ int count;
+ int ret;
+ int i;
+
+ count = of_property_count_u32_elems(node, propname);
+ if (count == -EINVAL)
+ return 0;
+ if (count <= 0)
+ return count;
+ if (count >= ARRAY_SIZE(zones))
+ return -EINVAL;
+
+ ret = of_property_read_u32_array(node, propname, zones, count);
+ if (ret < 0)
+ return ret;
+
+ /* Enable pwm input, and enable the selected zones */
+ ret = BIT(0);
+ for (i = 0; i < count; i++)
+ ret |= BIT(zones[i] + 1);
+
+ return ret;
+}
+
+static struct lm3533_bl_platform_data *lm3533_bl_of_parse(struct device *dev,
+ int *id)
+{
+ struct lm3533_bl_platform_data *bl_pdata;
+ struct device_node *node = dev->of_node;
+ int ret;
+ u32 reg;
+ u32 val;
+
+ bl_pdata = devm_kzalloc(dev, sizeof(*bl_pdata), GFP_KERNEL);
+ if (!bl_pdata)
+ return NULL;
+
+ ret = of_property_read_u32(node, "reg", &reg);
+ if (ret < 0) {
+ dev_err(dev, "invalid reg property\n");
+ return NULL;
+ }
+ *id = reg;
+
+ ret = of_property_read_string(node, "label",
+ (const char **)&bl_pdata->name);
+ if (ret < 0) {
+ dev_err(dev, "unable to parse label\n");
+ return NULL;
+ }
+
+ ret = of_property_read_u32(node, "led-max-microamp", &val);
+ if (ret < 0) {
+ dev_err(dev, "unable to parse led-max-microamp\n");
+ return NULL;
+ }
+ bl_pdata->max_current = val;
+
+ val = LM3533_BL_DEFAULT_BRIGHTNESS;
+ ret = of_property_read_u32(node, "default-brightness", &val);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(dev, "unable to parse default-brightness\n");
+ return NULL;
+ }
+ bl_pdata->default_brightness = val;
+
+ ret = lm3533_of_parse_pwm_zones(node);
+ if (ret < 0) {
+ dev_err(dev, "failed to parse ti,pwm-zones\n");
+ return NULL;
+ }
+ bl_pdata->pwm = ret;
+
+ return bl_pdata;
+}
+
static int lm3533_bl_probe(struct platform_device *pdev)
{
struct lm3533 *lm3533;
@@ -277,6 +358,7 @@ static int lm3533_bl_probe(struct platform_device *pdev)
struct backlight_device *bd;
struct backlight_properties props;
int ret;
+ int id;

dev_dbg(&pdev->dev, "%s\n", __func__);

@@ -284,14 +366,17 @@ static int lm3533_bl_probe(struct platform_device *pdev)
if (!lm3533)
return -EINVAL;

+ id = pdev->id;
pdata = dev_get_platdata(&pdev->dev);
+ if (!pdata)
+ pdata = lm3533_bl_of_parse(&pdev->dev, &id);
if (!pdata) {
dev_err(&pdev->dev, "no platform data\n");
return -EINVAL;
}

- if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
- dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
+ if (id < 0 || id >= LM3533_HVCTRLBANK_COUNT) {
+ dev_err(&pdev->dev, "illegal backlight id %d\n", id);
return -EINVAL;
}

@@ -300,7 +385,7 @@ static int lm3533_bl_probe(struct platform_device *pdev)
return -ENOMEM;

bl->lm3533 = lm3533;
- bl->id = pdev->id;
+ bl->id = id;

bl->cb.lm3533 = lm3533;
bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
@@ -394,10 +479,17 @@ static void lm3533_bl_shutdown(struct platform_device *pdev)
lm3533_ctrlbank_disable(&bl->cb);
}

+static const struct of_device_id lm3533_bl_of_match[] = {
+ { .compatible = "ti,lm3533-backlight", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, lm3533_bl_of_match);
+
static struct platform_driver lm3533_bl_driver = {
.driver = {
.name = "lm3533-backlight",
.pm = &lm3533_bl_pm_ops,
+ .of_match_table = lm3533_bl_of_match,
},
.probe = lm3533_bl_probe,
.remove = lm3533_bl_remove,
--
2.11.0