[PATCH v8 06/24] drivers/fsi: Set up links for slave communication
From: Christopher Bostic <hidden>
Date: 2017-06-06 21:09:32
Also in:
linux-devicetree, lkml
Subsystem:
fsi subsystem, the rest · Maintainers:
Eddie James, Linus Torvalds
Enable each link and send a break command, and try to detect a slave by reading from the SMODE register. Signed-off-by: Christopher Bostic <redacted> Signed-off-by: Joel Stanley <joel@jms.id.au> --- 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 1ec9790..235f17a 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c@@ -133,12 +133,45 @@ 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