[PATCH v2 100/101] staging/sm750fb: Parse option string with struct option_iter

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

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.

v2:
	* move string handling into separate patches

Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
 drivers/staging/sm750fb/sm750.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c
index f0dbf7535ca8..0e3712fcf0e0 100644
--- a/drivers/staging/sm750fb/sm750.c
+++ b/drivers/staging/sm750fb/sm750.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/aperture.h>
+#include <linux/cmdline.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/errno.h>
@@ -867,8 +868,9 @@ static int lynxfb_set_fbinfo(struct fb_info *info, int index)
 }
 
 /*	chip specific g_option configuration routine */
-static void sm750fb_setup(struct sm750_dev *sm750_dev, char *src)
+static void sm750fb_setup(struct sm750_dev *sm750_dev, const char *src)
 {
+	struct option_iter iter;
 	char *opt;
 	int swap;
 
@@ -889,7 +891,9 @@ static void sm750fb_setup(struct sm750_dev *sm750_dev, char *src)
 		goto NO_PARAM;
 	}
 
-	while ((opt = strsep(&src, ":")) != NULL && *opt != 0) {
+	option_iter_init(&iter, src);
+
+	while (option_iter_next(&iter, &opt)) {
 		dev_info(&sm750_dev->pdev->dev, "opt=%s\n", opt);
 		dev_info(&sm750_dev->pdev->dev, "src=%s\n", src);
 
@@ -924,6 +928,8 @@ static void sm750fb_setup(struct sm750_dev *sm750_dev, char *src)
 		}
 	}
 
+	option_iter_release(&iter);
+
 NO_PARAM:
 	if (sm750_dev->revid != SM750LE_REVISION_ID) {
 		if (sm750_dev->fb_count > 1) {
@@ -1095,9 +1101,10 @@ static void lynxfb_pci_remove(struct pci_dev *pdev)
 	iounmap(sm750_dev->pvMem);
 }
 
-static int __init lynxfb_setup(char *options)
+static int __init lynxfb_setup(const char *options)
 {
 	size_t len;
+	struct option_iter iter;
 	char *opt, *outbuf;
 
 	if (!options || !*options) {
@@ -1113,16 +1120,9 @@ static int __init lynxfb_setup(char *options)
 		return -ENOMEM;
 	g_settings = outbuf;
 
-	/*
-	 * Notes:
-	 * char * strsep(char **s,const char * ct);
-	 * @s: the string to be searched
-	 * @ct :the characters to search for
-	 *
-	 * strsep() updates @options to pointer after the first found token
-	 * it also returns the pointer ahead the token.
-	 */
-	while ((opt = strsep(&options, ":")) != NULL) {
+	option_iter_init(&iter, options);
+
+	while (option_iter_next(&iter, &opt)) {
 		/* options that mean for any lynx chips are configured here */
 		if (!strncmp(opt, "noaccel", strlen("noaccel"))) {
 			g_noaccel = 1;
@@ -1139,6 +1139,8 @@ static int __init lynxfb_setup(char *options)
 		}
 	}
 
+	option_iter_release(&iter);
+
 	/* misc g_settings are transport to chip specific routines */
 	pr_info("parameter left for chip specific analysis:%s\n", g_settings);
 	return 0;
-- 
2.39.2