drivers/fsi: Implement slave initialisation

Implement fsi_slave_init: if we can read a chip ID, create fsi_slave
devices and register with the driver core.

Includes changes from Christopher Bostic <cbostic@linux.vnet.ibm.com>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index 04c1a0efa7a7b12ec5733755727654cdf56dd8e7..e1006c6808a7e74dca4a6342e397ccc3ff41975f 100644 (file)
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -6,6 +6,7 @@ menu "FSI support"
 
 config FSI
        tristate "FSI support"
+       select CRC4
        ---help---
          FSI - the FRU Support Interface - is a simple bus for low-level
          access to POWER-based hardware.

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 235f17a6d89e8b81d1d8be3614c28135ffffc004..9d9adc17072c39d33ea503df562668c8a35d9679 100644 (file)
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -13,13 +13,17 @@
  * GNU General Public License for more details.
  */
 
+#include <linux/crc4.h>
 #include <linux/device.h>
 #include <linux/fsi.h>
 #include <linux/idr.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 
 #include "fsi-master.h"
 
+#define FSI_SLAVE_SIZE_23b             0x800000
+
 static DEFINE_IDA(master_ida);
 
 struct fsi_slave {
@@ -90,11 +94,70 @@ static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
                        addr, val, size);
 }
 
+static void fsi_slave_release(struct device *dev)
+{
+       struct fsi_slave *slave = to_fsi_slave(dev);
+
+       kfree(slave);
+}
+
 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 {
-       /* todo: initialise slave device, perform engine scan */
+       struct fsi_slave *slave;
+       uint32_t chip_id;
+       uint8_t crc;
+       int rc;
+
+       /* Currently, we only support single slaves on a link, and use the
+        * full 23-bit address range
+        */
+       if (id != 0)
+               return -EINVAL;
+
+       rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id));
+       if (rc) {
+               dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
+                               link, id, rc);
+               return -ENODEV;
+       }
+       chip_id = be32_to_cpu(chip_id);
+
+       crc = crc4(0, chip_id, 32);
+       if (crc) {
+               dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n",
+                               link, id);
+               return -EIO;
+       }
+
+       dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
+                       chip_id, master->idx, link, id);
+
+       /* We can communicate with a slave; create the slave device and
+        * register.
+        */
+       slave = kzalloc(sizeof(*slave), GFP_KERNEL);
+       if (!slave)
+               return -ENOMEM;
+
+       slave->master = master;
+       slave->dev.parent = &master->dev;
+       slave->dev.release = fsi_slave_release;
+       slave->link = link;
+       slave->id = id;
+       slave->size = FSI_SLAVE_SIZE_23b;
+
+       dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
+       rc = device_register(&slave->dev);
+       if (rc < 0) {
+               dev_warn(&master->dev, "failed to create slave device: %d\n",
+                               rc);
+               put_device(&slave->dev);
+               return rc;
+       }
+
+       /* todo: perform engine scan */
 
-       return -ENODEV;
+       return rc;
 }
 
 /* FSI master support */