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author | Darrick J. Wong <djwong@us.ibm.com> | 2007-01-11 14:14:57 -0800 |
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committer | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2007-01-13 16:13:00 -0600 |
commit | acbf167d4ad8c27f9743a4b539d51ae9535bf21c (patch) | |
tree | e53f8330f60acaef42d74a745b3dd5131b424e49 /drivers/scsi/scsi_transport_sas.c | |
parent | b218a0d8e250e0ae8fd4d4e45bd66a588b380752 (diff) | |
download | kernel_samsung_espresso10-acbf167d4ad8c27f9743a4b539d51ae9535bf21c.zip kernel_samsung_espresso10-acbf167d4ad8c27f9743a4b539d51ae9535bf21c.tar.gz kernel_samsung_espresso10-acbf167d4ad8c27f9743a4b539d51ae9535bf21c.tar.bz2 |
[SCSI] libsas: Add a sysfs knob to enable/disable a phy
This patch lets a user arbitrarily enable or disable a phy via sysfs.
Potential applications include shutting down a phy to replace one
lane of wide port, and (more importantly) providing a method for the
libata SATL to control the phy.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/scsi_transport_sas.c')
-rw-r--r-- | drivers/scsi/scsi_transport_sas.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c index 5c0b75b..9e38c18 100644 --- a/drivers/scsi/scsi_transport_sas.c +++ b/drivers/scsi/scsi_transport_sas.c @@ -336,6 +336,51 @@ show_sas_device_type(struct class_device *cdev, char *buf) } static CLASS_DEVICE_ATTR(device_type, S_IRUGO, show_sas_device_type, NULL); +static ssize_t do_sas_phy_enable(struct class_device *cdev, + size_t count, int enable) +{ + struct sas_phy *phy = transport_class_to_phy(cdev); + struct Scsi_Host *shost = dev_to_shost(phy->dev.parent); + struct sas_internal *i = to_sas_internal(shost->transportt); + int error; + + error = i->f->phy_enable(phy, enable); + if (error) + return error; + phy->enabled = enable; + return count; +}; + +static ssize_t store_sas_phy_enable(struct class_device *cdev, + const char *buf, size_t count) +{ + if (count < 1) + return -EINVAL; + + switch (buf[0]) { + case '0': + do_sas_phy_enable(cdev, count, 0); + break; + case '1': + do_sas_phy_enable(cdev, count, 1); + break; + default: + return -EINVAL; + } + + return count; +} + +static ssize_t show_sas_phy_enable(struct class_device *cdev, char *buf) +{ + struct sas_phy *phy = transport_class_to_phy(cdev); + + return snprintf(buf, 20, "%d", phy->enabled); +} + +static CLASS_DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, show_sas_phy_enable, + store_sas_phy_enable); + static ssize_t do_sas_phy_reset(struct class_device *cdev, size_t count, int hard_reset) { @@ -435,6 +480,7 @@ struct sas_phy *sas_phy_alloc(struct device *parent, int number) return NULL; phy->number = number; + phy->enabled = 1; device_initialize(&phy->dev); phy->dev.parent = get_device(parent); @@ -1389,6 +1435,10 @@ static int sas_user_scan(struct Scsi_Host *shost, uint channel, SETUP_TEMPLATE_RW(phy_attrs, field, S_IRUGO | S_IWUSR, 1, \ !i->f->set_phy_speed, S_IRUGO) +#define SETUP_OPTIONAL_PHY_ATTRIBUTE_RW(field, func) \ + SETUP_TEMPLATE_RW(phy_attrs, field, S_IRUGO | S_IWUSR, 1, \ + !i->f->func, S_IRUGO) + #define SETUP_PORT_ATTRIBUTE(field) \ SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1) @@ -1479,6 +1529,7 @@ sas_attach_transport(struct sas_function_template *ft) SETUP_PHY_ATTRIBUTE(phy_reset_problem_count); SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(link_reset, phy_reset); SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(hard_reset, phy_reset); + SETUP_OPTIONAL_PHY_ATTRIBUTE_RW(enable, phy_enable); i->phy_attrs[count] = NULL; count = 0; |