fsi: Add support for device-tree provided chip IDs

They get retrieved from the device-tree and exposed
as an attribute in sysfs

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index e9f8813b75e6e4cdd977b7aba4caf6c07cd542ad..eab6c5c4990edff9392e4a1ad752116a03afae6c 100644 (file)
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -80,6 +80,7 @@ struct fsi_slave {
        struct fsi_master       *master;
        int                     id;
        int                     link;
+       int                     chip_id;
        uint32_t                size;   /* size of slave address space */
        u8                      t_send_delay;
        u8                      t_echo_delay;
@@ -717,6 +718,17 @@ static ssize_t slave_send_echo_store(struct device *dev,
 static DEVICE_ATTR(send_echo_delays, 0600,
                   slave_send_echo_show, slave_send_echo_store);
 
+static ssize_t chip_id_show(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+       struct fsi_slave *slave = to_fsi_slave(dev);
+
+       return sprintf(buf, "%d\n", slave->chip_id);
+}
+
+static DEVICE_ATTR_RO(chip_id);
+
 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 {
        uint32_t chip_id;
@@ -780,6 +792,14 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
        slave->t_send_delay = 16;
        slave->t_echo_delay = 16;
 
+       /* Get chip ID if any */
+       slave->chip_id = -1;
+       if (slave->dev.of_node) {
+               uint32_t prop;
+               if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop))
+                       slave->chip_id = prop;
+
+       }
        rc = fsi_slave_set_smode(slave);
        if (rc) {
                dev_warn(&master->dev,
@@ -814,6 +834,10 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
        if (rc)
                dev_warn(&slave->dev, "failed to create delay attr: %d\n", rc);
 
+       rc = device_create_file(&slave->dev, &dev_attr_chip_id);
+       if (rc)
+               dev_warn(&slave->dev, "failed to create chip id: %d\n", rc);
+
        rc = fsi_slave_scan(slave);
        if (rc)
                dev_dbg(&master->dev, "failed during slave scan with: %d\n",