linux-kernel - [PATCH 1/2] fb: backlight: HX8357: Make IM pins optionnal

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Date:	Fri, 21 Jun 2013 20:27:38 +0200
From:	Alexandre Belloni <alexandre.belloni@...e-electrons.com>
To:	linux-fbdev@...r.kernel.org,
	Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>
Cc:	jimwall@...om, brian@...stalfontz.com,
	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	linux-kernel@...r.kernel.org, Richard Purdie <rpurdie@...ys.net>,
	Florian Tobias Schandinat <FlorianSchandinat@....de>,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>
Subject: [PATCH 1/2] fb: backlight: HX8357: Make IM pins optionnal

From: Maxime Ripard <maxime.ripard@...e-electrons.com>

Signed-off-by: Alexandre Belloni <alexandre.belloni@...e-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@...e-electrons.com>
---
 drivers/video/backlight/hx8357.c | 53 +++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 22 deletions(-)

diff --git a/drivers/video/backlight/hx8357.c b/drivers/video/backlight/hx8357.c
index a0482b5..69f5672 100644
--- a/drivers/video/backlight/hx8357.c
+++ b/drivers/video/backlight/hx8357.c
@@ -76,6 +76,7 @@ struct hx8357_data {
 	unsigned		reset;
 	struct spi_device	*spi;
 	int			state;
+	u8			use_im_pins;
 };
 
 static u8 hx8357_seq_power[] = {
@@ -250,9 +251,11 @@ static int hx8357_lcd_init(struct lcd_device *lcdev)
 	 * Set the interface selection pins to SPI mode, with three
 	 * wires
 	 */
-	gpio_set_value_cansleep(lcd->im_pins[0], 1);
-	gpio_set_value_cansleep(lcd->im_pins[1], 0);
-	gpio_set_value_cansleep(lcd->im_pins[2], 1);
+	if (lcd->use_im_pins) {
+		gpio_set_value_cansleep(lcd->im_pins[0], 1);
+		gpio_set_value_cansleep(lcd->im_pins[1], 0);
+		gpio_set_value_cansleep(lcd->im_pins[2], 1);
+	}
 
 	/* Reset the screen */
 	gpio_set_value(lcd->reset, 1);
@@ -424,26 +427,32 @@ static int hx8357_probe(struct spi_device *spi)
 		return -EINVAL;
 	}
 
-	for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
-		lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
-						"im-gpios", i);
-		if (lcd->im_pins[i] == -EPROBE_DEFER) {
-			dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
-			return -EPROBE_DEFER;
-		}
-		if (!gpio_is_valid(lcd->im_pins[i])) {
-			dev_err(&spi->dev, "Missing dt property: im-gpios\n");
-			return -EINVAL;
+	if (of_find_property(spi->dev.of_node, "im-gpios", NULL)) {
+		lcd->use_im_pins = 1;
+
+		for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
+			lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
+							    "im-gpios", i);
+			if (lcd->im_pins[i] == -EPROBE_DEFER) {
+				dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
+				return -EPROBE_DEFER;
+			}
+			if (!gpio_is_valid(lcd->im_pins[i])) {
+				dev_err(&spi->dev, "Missing dt property: im-gpios\n");
+				return -EINVAL;
+			}
+
+			ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
+						    GPIOF_OUT_INIT_LOW,
+						    "im_pins");
+			if (ret) {
+				dev_err(&spi->dev, "failed to request gpio %d: %d\n",
+					lcd->im_pins[i], ret);
+				return -EINVAL;
+			}
 		}
-
-		ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
-					GPIOF_OUT_INIT_LOW, "im_pins");
-		if (ret) {
-			dev_err(&spi->dev, "failed to request gpio %d: %d\n",
-				lcd->im_pins[i], ret);
-			return -EINVAL;
-		}
-	}
+	} else
+		lcd->use_im_pins = 0;
 
 	lcdev = lcd_device_register("mxsfb", &spi->dev, lcd, &hx8357_ops);
 	if (IS_ERR(lcdev)) {
-- 
1.8.1.2

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