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From: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
To: LFBDEV <linux-fbdev@vger.kernel.org>,
	Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	"Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Subject: [PATCH] fbdev: ssd1307fb: return proper error code if write command fails
Date: Wed, 14 Jan 2015 08:24:49 +0000	[thread overview]
Message-ID: <1421223889-9448-1-git-send-email-prabhakar.csengg@gmail.com> (raw)

this patch fixes ssd1307fb_ssd1306_init() function to return
proper error codes in case of failures.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
---
 drivers/video/fbdev/ssd1307fb.c | 54 ++++++++++++++++++++++++++++++-----------
 1 file changed, 40 insertions(+), 14 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index f4daa59..528ea16 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -320,7 +320,9 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
 
 	/* Set initial contrast */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x7f);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x7f);
 	if (ret < 0)
 		return ret;
 
@@ -336,63 +338,87 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
 
 	/* Set multiplex ratio value */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
-	ret = ret & ssd1307fb_write_cmd(par->client, par->height - 1);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, par->height - 1);
 	if (ret < 0)
 		return ret;
 
 	/* set display offset value */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
+	if (ret < 0)
+		return ret;
 	ret = ssd1307fb_write_cmd(par->client, 0x20);
 	if (ret < 0)
 		return ret;
 
 	/* Set clock frequency */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0xf0);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0xf0);
 	if (ret < 0)
 		return ret;
 
 	/* Set precharge period in number of ticks from the internal clock */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x22);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x22);
 	if (ret < 0)
 		return ret;
 
 	/* Set COM pins configuration */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x22);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x22);
 	if (ret < 0)
 		return ret;
 
 	/* Set VCOMH */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x49);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x49);
 	if (ret < 0)
 		return ret;
 
 	/* Turn on the DC-DC Charge Pump */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x14);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x14);
 	if (ret < 0)
 		return ret;
 
 	/* Switch to horizontal addressing mode */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
-	ret = ret & ssd1307fb_write_cmd(par->client,
-					SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client,
+				  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
 	if (ret < 0)
 		return ret;
 
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x0);
-	ret = ret & ssd1307fb_write_cmd(par->client, par->width - 1);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x0);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, par->width - 1);
 	if (ret < 0)
 		return ret;
 
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
-	ret = ret & ssd1307fb_write_cmd(par->client, 0x0);
-	ret = ret & ssd1307fb_write_cmd(par->client,
-					par->page_offset + (par->height / 8) - 1);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client, 0x0);
+	if (ret < 0)
+		return ret;
+	ret = ssd1307fb_write_cmd(par->client,
+				  par->page_offset + (par->height / 8) - 1);
 	if (ret < 0)
 		return ret;
 
-- 
1.9.1


             reply	other threads:[~2015-01-14  8:24 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-14  8:24 Lad, Prabhakar [this message]
2015-01-14 11:07 ` [PATCH] fbdev: ssd1307fb: return proper error code if write command fails Maxime Ripard

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