BUG: Staging: fbtft: Switch to the gpio descriptor interface

[Phil Reid]

G'day Nishad,

I'm just wondering if the commit
c440eee1a7a1d0f "Staging: fbtft: Switch to the gpio descriptor interface"
was tested on anything.

I've had to apply the following patch to get my display functioning again.

in particular the devm_gpiod_get_index using dev->driver->name for the gpio lookup seems
wrong.

Also I've had to invert the polarity of the reset-gpios in the DT file for the display to function.

this code:
	gpiod_set_value_cansleep(par->gpio.reset, 0);
	usleep_range(20, 40);
	gpiod_set_value_cansleep(par->gpio.reset, 1);

could be read as deasserting the reset line and then asserting it.
So I've had to specify and active high reset line in the DT.

Regards
Phil





diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index 9b07bad..6fe7cb5 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -79,18 +79,16 @@ static int fbtft_request_one_gpio(struct fbtft_par *par,
  	struct device_node *node = dev->of_node;
  	int ret = 0;

-	if (of_find_property(node, name, NULL)) {
-		*gpiop = devm_gpiod_get_index(dev, dev->driver->name, index,
-					      GPIOD_OUT_HIGH);
-		if (IS_ERR(*gpiop)) {
-			ret = PTR_ERR(*gpiop);
-			dev_err(dev,
-				"Failed to request %s GPIO:%d\n", name, ret);
-			return ret;
-		}
-		fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO\n",
-			      __func__, name);
+	*gpiop = devm_gpiod_get_index_optional(dev, name, index,
+				      GPIOD_OUT_HIGH);
+	if (IS_ERR(*gpiop)) {
+		ret = PTR_ERR(*gpiop);
+		dev_err(dev,
+			"Failed to request %s GPIO: (%d)\n", name, ret);
+		return ret;
  	}
+	fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO\n",
+		      __func__, name);

  	return ret;
  }
@@ -103,34 +101,34 @@ static int fbtft_request_gpios_dt(struct fbtft_par *par)
  	if (!par->info->device->of_node)
  		return -EINVAL;

-	ret = fbtft_request_one_gpio(par, "reset-gpios", 0, &par->gpio.reset);
+	ret = fbtft_request_one_gpio(par, "reset", 0, &par->gpio.reset);
  	if (ret)
  		return ret;
-	ret = fbtft_request_one_gpio(par, "dc-gpios", 0, &par->gpio.dc);
+	ret = fbtft_request_one_gpio(par, "dc", 0, &par->gpio.dc);
  	if (ret)
  		return ret;
-	ret = fbtft_request_one_gpio(par, "rd-gpios", 0, &par->gpio.rd);
+	ret = fbtft_request_one_gpio(par, "rd", 0, &par->gpio.rd);
  	if (ret)
  		return ret;
-	ret = fbtft_request_one_gpio(par, "wr-gpios", 0, &par->gpio.wr);
+	ret = fbtft_request_one_gpio(par, "wr", 0, &par->gpio.wr);
  	if (ret)
  		return ret;
-	ret = fbtft_request_one_gpio(par, "cs-gpios", 0, &par->gpio.cs);
+	ret = fbtft_request_one_gpio(par, "cs", 0, &par->gpio.cs);
  	if (ret)
  		return ret;
-	ret = fbtft_request_one_gpio(par, "latch-gpios", 0, &par->gpio.latch);
+	ret = fbtft_request_one_gpio(par, "latch", 0, &par->gpio.latch);
  	if (ret)
  		return ret;
  	for (i = 0; i < 16; i++) {
-		ret = fbtft_request_one_gpio(par, "db-gpios", i,
+		ret = fbtft_request_one_gpio(par, "db", i,
  					     &par->gpio.db[i]);
  		if (ret)
  			return ret;
-		ret = fbtft_request_one_gpio(par, "led-gpios", i,
+		ret = fbtft_request_one_gpio(par, "led", i,
  					     &par->gpio.led[i]);
  		if (ret)
  			return ret;
-		ret = fbtft_request_one_gpio(par, "aux-gpios", i,
+		ret = fbtft_request_one_gpio(par, "aux", i,
  					     &par->gpio.aux[i]);
  		if (ret)
  			return ret;