[PATCH v4 06/23] drivers/fsi: Set up links for slave communication

From: Christopher Bostic
Date: Wed Mar 29 2017 - 13:48:52 EST


From: Chris Bostic <cbostic@xxxxxxxxxxxxxxxxxx>

Enable each link and send a break command, and try to detect a slave by
reading from the SMODE register.

Signed-off-by: Chris Bostic <cbostic@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/fsi/fsi-core.c | 37 +++++++++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 32698ed..6e1cfdf 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -157,12 +157,45 @@ static int fsi_master_write(struct fsi_master *master, int link,
return master->write(master, link, slave_id, addr, val, size);
}

+static int fsi_master_link_enable(struct fsi_master *master, int link)
+{
+ if (master->link_enable)
+ return master->link_enable(master, link);
+
+ return 0;
+}
+
+/*
+ * Issue a break command on this link
+ */
+static int fsi_master_break(struct fsi_master *master, int link)
+{
+ if (master->send_break)
+ return master->send_break(master, link);
+
+ return 0;
+}
+
static int fsi_master_scan(struct fsi_master *master)
{
- int link;
+ int link, rc;
+
+ for (link = 0; link < master->n_links; link++) {
+ rc = fsi_master_link_enable(master, link);
+ if (rc) {
+ dev_dbg(&master->dev,
+ "enable link %d failed: %d\n", link, rc);
+ continue;
+ }
+ rc = fsi_master_break(master, link);
+ if (rc) {
+ dev_dbg(&master->dev,
+ "break to link %d failed: %d\n", link, rc);
+ continue;
+ }

- for (link = 0; link < master->n_links; link++)
fsi_slave_init(master, link, 0);
+ }

return 0;
}
--
1.8.2.2