From:   Thomas Zimmermann <tzimmermann@suse.de>
To:     deller@gmx.de, paulus@samba.org, benh@kernel.crashing.org,
        linux@armlinux.org.uk, pjones@redhat.com, timur@kernel.org,
        adaplas@gmail.com, s.hauer@pengutronix.de, shawnguo@kernel.org,
        mbroemme@libmpq.org, thomas@winischhofer.net,
        James.Bottomley@HansenPartnership.com, spock@gentoo.org,
        sudipm.mukherjee@gmail.com, teddy.wang@siliconmotion.com,
        geert+renesas@glider.be, corbet@lwn.net
Cc:     linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org,
        Thomas Zimmermann <tzimmermann@suse.de>
Subject: [PATCH 29/99] fbdev/grvga: Parse option string with struct option_iter
Date:   Mon,  6 Mar 2023 16:59:06 +0100
Message-Id: <20230306160016.4459-30-tzimmermann@suse.de>
In-Reply-To: <20230306160016.4459-1-tzimmermann@suse.de>
References: <20230306160016.4459-1-tzimmermann@suse.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Use struct option_iter to walk over the individual options in the
driver's option string. Replaces the hand-written strsep() loop with
a clean interface. The helpers for struct option_iter handle empty
option strings and empty options transparently. The struct's _init
and _release functions duplicate and release the option string's
memory buffer as needed.

Done in preparation of constifying the option string.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/grvga.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/video/fbdev/grvga.c b/drivers/video/fbdev/grvga.c
index bb4baec2eccc..f803dc37c891 100644
--- a/drivers/video/fbdev/grvga.c
+++ b/drivers/video/fbdev/grvga.c
@@ -10,6 +10,7 @@
  * Contributors: Kristoffer Glembo <kristoffer@gaisler.com>
  */
 
+#include <linux/cmdline.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/of_platform.h>
@@ -334,6 +335,8 @@ static int grvga_probe(struct platform_device *dev)
 	unsigned long grvga_mem_size = 0;
 	struct grvga_par *par = NULL;
 	char *options = NULL, *mode_opt = NULL;
+	struct option_iter iter;
+	const char *this_opt;
 
 	info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
 	if (!info)
@@ -353,15 +356,13 @@ static int grvga_probe(struct platform_device *dev)
 	if (!options || !*options)
 		options =  "640x480-8@60";
 
-	while (1) {
-		char *this_opt = strsep(&options, ",");
-
-		if (!this_opt)
-			break;
+	option_iter_init(&iter, options);
 
+	while (option_iter_next(&iter, this_opt)) {
 		if (!strncmp(this_opt, "custom", 6)) {
 			if (grvga_parse_custom(this_opt, &info->var) < 0) {
 				dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
+				option_iter_release(&iter);
 				retval = -EINVAL;
 				goto free_fb;
 			}
@@ -385,6 +386,8 @@ static int grvga_probe(struct platform_device *dev)
 		}
 	}
 
+	option_iter_release(&iter);
+
 	par = info->par;
 	info->fbops = &grvga_ops;
 	info->fix = grvga_fix;
-- 
2.39.2