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path: root/drivers/ata/libata-scsi.c
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Diffstat (limited to 'drivers/ata/libata-scsi.c')
-rw-r--r--drivers/ata/libata-scsi.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index f752eddc19ed..93bd36c19690 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -110,6 +110,74 @@ static struct scsi_transport_template ata_scsi_transport_template = {
};
+static const struct {
+ enum link_pm value;
+ const char *name;
+} link_pm_policy[] = {
+ { NOT_AVAILABLE, "max_performance" },
+ { MIN_POWER, "min_power" },
+ { MAX_PERFORMANCE, "max_performance" },
+ { MEDIUM_POWER, "medium_power" },
+};
+
+const char *ata_scsi_lpm_get(enum link_pm policy)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(link_pm_policy); i++)
+ if (link_pm_policy[i].value == policy)
+ return link_pm_policy[i].name;
+
+ return NULL;
+}
+
+static ssize_t ata_scsi_lpm_put(struct class_device *class_dev,
+ const char *buf, size_t count)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+ enum link_pm policy = 0;
+ int i;
+
+ /*
+ * we are skipping array location 0 on purpose - this
+ * is because a value of NOT_AVAILABLE is displayed
+ * to the user as max_performance, but when the user
+ * writes "max_performance", they actually want the
+ * value to match MAX_PERFORMANCE.
+ */
+ for (i = 1; i < ARRAY_SIZE(link_pm_policy); i++) {
+ const int len = strlen(link_pm_policy[i].name);
+ if (strncmp(link_pm_policy[i].name, buf, len) == 0 &&
+ buf[len] == '\n') {
+ policy = link_pm_policy[i].value;
+ break;
+ }
+ }
+ if (!policy)
+ return -EINVAL;
+
+ ata_lpm_schedule(ap, policy);
+ return count;
+}
+
+static ssize_t
+ata_scsi_lpm_show(struct class_device *class_dev, char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+ const char *policy =
+ ata_scsi_lpm_get(ap->pm_policy);
+
+ if (!policy)
+ return -EINVAL;
+
+ return snprintf(buf, 23, "%s\n", policy);
+}
+CLASS_DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
+ ata_scsi_lpm_show, ata_scsi_lpm_put);
+EXPORT_SYMBOL_GPL(class_device_attr_link_power_management_policy);
+
static void ata_scsi_invalid_field(struct scsi_cmnd *cmd,
void (*done)(struct scsi_cmnd *))
{