[M] Change in flashrom[master]: linux_mtd.c: Factor out detection phases from setup func

[Edward O'Callaghan (Code Review)]

Attention is currently required from: Nikolai Artemiev.

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/73495 )

Change subject: linux_mtd.c: Factor out detection phases from setup func
......................................................................

linux_mtd.c: Factor out detection phases from setup func

The setup phase function is performing detection logic,
move this to a earlier phase in the init sequence such
that it can be used seperately.

Change-Id: I15915b71e1a030548c5f082cde78c42ece28bb37
Signed-off-by: Edward O'Callaghan 
---
M linux_mtd.c
1 file changed, 70 insertions(+), 59 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/95/73495/1

diff --git a/linux_mtd.c b/linux_mtd.c
index b3be72a..708e340 100644
--- a/linux_mtd.c
+++ b/linux_mtd.c
@@ -443,57 +443,6 @@
    .wp_get_ranges	= linux_mtd_wp_get_available_ranges,
 };

-/* Returns 0 if setup is successful, non-zero to indicate error */
-static int linux_mtd_setup(int dev_num, struct linux_mtd_data *data)
-{
-	char sysfs_path[32];
-	int ret = 1;
-
-	/* Start by checking /sys/class/mtd/mtdN/type which should be "nor" for NOR flash */
-	if (snprintf(sysfs_path, sizeof(sysfs_path), "%s/mtd%d/", LINUX_MTD_SYSFS_ROOT, dev_num) < 0)
-		goto linux_mtd_setup_exit;
-
-	char buf[4] = { 0 };
-	if (read_sysfs_string(sysfs_path, "type", buf, sizeof(buf)))
-		return 1;
-
-	if (strcmp(buf, "nor")) {
-		msg_perr("MTD device %d type is not "nor"\n", dev_num);
-		goto linux_mtd_setup_exit;
-	}
-
-	/* sysfs shows the correct device type, see if corresponding device node exists */
-	char dev_path[32];
-	struct stat s;
-	snprintf(dev_path, sizeof(dev_path), "%s/mtd%d", LINUX_DEV_ROOT, dev_num);
-	errno = 0;
-	if (stat(dev_path, &s) < 0) {
-		msg_pdbg("Cannot stat "%s": %s\n", dev_path, strerror(errno));
-		goto linux_mtd_setup_exit;
-	}
-
-	/* so far so good, get more info from other files in this dir */
-	if (snprintf(sysfs_path, sizeof(sysfs_path), "%s/mtd%d/", LINUX_MTD_SYSFS_ROOT, dev_num) < 0)
-		goto linux_mtd_setup_exit;
-	if (get_mtd_info(sysfs_path, data))
-		goto linux_mtd_setup_exit;
-
-	/* open file stream and go! */
-	if ((data->dev_fp = fopen(dev_path, "r+")) == NULL) {
-		msg_perr("Cannot open file stream for %s\n", dev_path);
-		goto linux_mtd_setup_exit;
-	}
-	ret = setvbuf(data->dev_fp, NULL, _IONBF, 0);
-	if (ret)
-		msg_pwarn("Failed to set MTD device to unbuffered: %d\n", ret);
-
-	msg_pinfo("Opened %s successfully\n", dev_path);
-
-	ret = 0;
-linux_mtd_setup_exit:
-	return ret;
-}
-
 static int get_params(const struct programmer_cfg *cfg, int *dev_num)
 {
    char *param_str = extract_programmer_param_str(cfg, "dev");
@@ -516,17 +465,18 @@
    return 0;
 }

-static int check_sysfs_devnum_path(int dev_num)
+static int detect_spinor_in_sysfs(int dev_num, char *dev_path, size_t dp_len)
 {
+	/* Start by checking /sys/class/mtd/mtdN/type which should be "nor" for NOR flash */
+	char sysfs_path[32];
+	if (snprintf(sysfs_path, sizeof(sysfs_path), "%s/mtd%d", LINUX_MTD_SYSFS_ROOT, dev_num) < 0)
+		return -1;
+
    /*
     * If user specified the MTD device number then error out if it doesn't
     * appear to exist. Otherwise assume the error is benign and print a
     * debug message. Bail out in either case.
     */
-	char sysfs_path[32];
-	if (snprintf(sysfs_path, sizeof(sysfs_path), "%s/mtd%d", LINUX_MTD_SYSFS_ROOT, dev_num) < 0)
-		return -1;
-
    struct stat s;
    if (stat(sysfs_path, &s) < 0) {
    	if (dev_num)
@@ -535,17 +485,64 @@
    		msg_pdbg("%s does not exist\n", sysfs_path);
    	return -1;
    }
+
+	/* Check sysfs shows the correct device type. */
+	char buf[4] = { 0 };
+	if (read_sysfs_string(sysfs_path, "type", buf, sizeof(buf)))
+		return -1;
+
+	if (strcmp(buf, "nor")) {
+		msg_perr("MTD device %d type is not "nor"\n", dev_num);
+		return -1;
+	}
+
+	/* Check if the corresponding device node exists. */
+	snprintf(dev_path, dp_len, "%s/mtd%d", LINUX_DEV_ROOT, dev_num);
+	errno = 0;
+	if (stat(dev_path, &s) < 0) {
+		msg_pdbg("Cannot stat "%s": %s\n", dev_path, strerror(errno));
+		return -1;
+	}
+
    return 0;
 }

+/* Returns 0 if setup is successful, non-zero to indicate error */
+static int linux_mtd_setup(int dev_num, const char *dev_path, struct linux_mtd_data *data)
+{
+	char sysfs_path[32];
+	int ret = 1;
+
+	/* Get more info from other files in the sysfs_path dir. */
+	if (snprintf(sysfs_path, sizeof(sysfs_path), "%s/mtd%d/", LINUX_MTD_SYSFS_ROOT, dev_num) < 0)
+		goto linux_mtd_setup_exit;
+	if (get_mtd_info(sysfs_path, data))
+		goto linux_mtd_setup_exit;
+
+	/* open file stream and go! */
+	if ((data->dev_fp = fopen(dev_path, "r+")) == NULL) {
+		msg_perr("Cannot open file stream for %s\n", dev_path);
+		goto linux_mtd_setup_exit;
+	}
+	ret = setvbuf(data->dev_fp, NULL, _IONBF, 0);
+	if (ret)
+		msg_pwarn("Failed to set MTD device to unbuffered: %d\n", ret);
+
+	msg_pinfo("Opened %s successfully\n", dev_path);
+
+	ret = 0;
+linux_mtd_setup_exit:
+	return ret;
+}
+
 static int linux_mtd_init(const struct programmer_cfg *cfg)
 {
    int dev_num;
-
    if (get_params(cfg, &dev_num) < 0)
    	return 1;

-	if (check_sysfs_devnum_path(dev_num) < 0)
+	char dev_path[32];
+	if (detect_spinor_in_sysfs(dev_num, dev_path, sizeof(dev_path)) < 0)
    	return 1;

struct linux_mtd_data *data = calloc(1, sizeof(*data));
@@ -555,7 +552,7 @@
    }

/* Get MTD info and store it in `data` */
-	if (linux_mtd_setup(dev_num, data)) {
+	if (linux_mtd_setup(dev_num, dev_path, data)) {
    	free(data);
    	return 1;
    }