Change in flashrom[master]: pci2: add device enable/disable

[Luc Verhaegen (Code Review)]

Luc Verhaegen has uploaded this change for review. ( https://review.coreboot.org/29081

Change subject: pci2: add device enable/disable
......................................................................

pci2: add device enable/disable

Change-Id: I79bbc5c4b0f571df692e0992f43b46da7ab3bf01
Signed-off-by: Luc Verhaegen 
---
M pcidev.c
M programmer.h
2 files changed, 120 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/81/29081/1

diff --git a/pcidev.c b/pcidev.c
index da4e2a3..7680e78 100644
--- a/pcidev.c
+++ b/pcidev.c
@@ -420,6 +420,115 @@
 /*
  *
  */
+int
+flashrom_pci_device_enable(struct flashrom_pci_device *device)
+{
+	char filename[1024];
+	int fd, ret;
+	char enable;
+
+	if (device->enabled)
+		return 0;
+
+	snprintf(filename, sizeof(filename) - 1,
+		 "%senable", device->sysfs_path);
+
+	fd = open(filename, O_RDWR);
+	if (fd == -1) {
+		msg_perr("%s: failed to open %s: %s\n",
+			 __func__, filename, strerror(errno));
+		return errno;
+	}
+
+	ret = read(fd, &enable, 1);
+	if (ret != 1) {
+		close(fd);
+		msg_perr("%s: failed to read %s: %s\n",
+			 __func__, filename, strerror(errno));
+		return errno;
+	}
+
+	if (enable == '0') {
+		device->was_disabled = true;
+		ret = write(fd, "1", 1);
+		if (ret != 1) {
+			close(fd);
+			msg_perr("%s: failed to write %s: %s\n",
+				 __func__, filename, strerror(errno));
+			return errno;
+		}
+	} else if (enable != '1') {
+		close(fd);
+		msg_perr("%s: invalid value read from %s: %c\n",
+			 __func__, filename, enable);
+		return EINVAL;
+	}
+
+	close(fd);
+
+	device->enabled = true;
+
+	return 0;
+}
+
+/*
+ *
+ */
+int
+flashrom_pci_device_disable(struct flashrom_pci_device *device)
+{
+	char filename[1024];
+	int fd, ret;
+	char enable;
+
+	/* We do not want to disable the device if we did not enable it */
+	if (!device->enabled || !device->was_disabled)
+		return 0;
+
+	snprintf(filename, sizeof(filename) - 1,
+		 "%senable", device->sysfs_path);
+
+	fd = open(filename, O_RDWR);
+	if (fd == -1) {
+		msg_perr("%s: failed to open %s: %s\n",
+			 __func__, filename, strerror(errno));
+		return errno;
+	}
+
+	ret = read(fd, &enable, 1);
+	if (ret != 1) {
+		close(fd);
+		msg_perr("%s: failed to read %s: %s\n",
+			 __func__, filename, strerror(errno));
+		return errno;
+	}
+
+	if (enable == '1') {
+		ret = write(fd, "0", 1);
+		if (ret != 1) {
+			close(fd);
+			msg_perr("%s: failed to write %s: %s\n",
+				 __func__, filename, strerror(errno));
+			return errno;
+		}
+	} else if (enable != '0') {
+		close(fd);
+		msg_perr("%s: invalid value read from %s: %c\n",
+			 __func__, filename, enable);
+		return EINVAL;
+	}
+
+	close(fd);
+
+	device->enabled = false;
+
+	return 0;
+}
+
+
+/*
+ *
+ */
 static int
 flashrom_pci_device_shutdown(void *data)
 {
@@ -433,6 +542,8 @@

flashrom_pci_mmio_unmap(device);

+	flashrom_pci_device_disable(device);
+
    free(device->sysfs_path);
    device->sysfs_path = NULL;

@@ -533,6 +644,9 @@

register_shutdown(flashrom_pci_device_shutdown, device);

+	if (flashrom_pci_device_enable(device))
+		return NULL;
+
    return device;
 }

diff --git a/programmer.h b/programmer.h
index 1a7af7a..7ec4291 100644
--- a/programmer.h
+++ b/programmer.h
@@ -872,9 +872,15 @@
    size_t mmio_size;

const void *private; /* programmer specific hook */
+
+	/* housekeeping */
+	bool enabled;
+	bool was_disabled;
 };

struct flashrom_pci_device *flashrom_pci_init(const struct flashrom_pci_match *matches);
+int flashrom_pci_device_enable(struct flashrom_pci_device *device);
+int flashrom_pci_device_disable(struct flashrom_pci_device *device);
 int flashrom_pci_mmio_map(struct flashrom_pci_device *device, int bar);
 void flashrom_pci_mmio_unmap(struct flashrom_pci_device *device);