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authorMarek Vasut <marex@denx.de>2021-06-10 14:00:00 +0200
committerTom Rini <trini@konsulko.com>2021-06-29 21:03:40 -0400
commit5da3de6afa46086f88084d622fb5923e57976bc0 (patch)
tree37f3999a4a45294d1d274e5d6a71d8aca4727c4f
parent8fba49bc8efb5ab5ee63666c0ab6cf2130fd3059 (diff)
downloadu-boot-WIP/spi-speed-change.zip
u-boot-WIP/spi-speed-change.tar.gz
u-boot-WIP/spi-speed-change.tar.bz2
spi: Update speed/mode on changeWIP/spi-speed-change
The spi_get_bus_and_cs() may be called on the same bus and chipselect with different frequency or mode. This is valid usecase, but the code fails to notify the controller of such a configuration change. Call spi_set_speed_mode() in case bus frequency or bus mode changed to let the controller update the configuration. The problem can easily be triggered using the sspi command: => sspi 0:0@1000 => sspi 0:0@2000 Without this patch, both transfers happen at 1000 Hz. With this patch, the later transfer happens correctly at 2000 Hz. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Jagan Teki <jagan@amarulasolutions.com> Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
-rw-r--r--drivers/spi/spi-uclass.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index ee30110..d867b27 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -391,6 +391,8 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
} else if (ret) {
dev_err(bus, "Invalid chip select %d:%d (err=%d)\n", busnum, cs, ret);
return ret;
+ } else if (dev) {
+ plat = dev_get_parent_plat(dev);
}
if (!device_active(dev)) {
@@ -416,12 +418,22 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
goto err;
}
+ /* In case bus frequency or mode changed, update it. */
+ if ((speed && bus_data->speed && bus_data->speed != speed) ||
+ (plat && plat->mode != mode)) {
+ ret = spi_set_speed_mode(bus, speed, mode);
+ if (ret)
+ goto err_speed_mode;
+ }
+
*busp = bus;
*devp = slave;
log_debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
return 0;
+err_speed_mode:
+ spi_release_bus(slave);
err:
log_debug("%s: Error path, created=%d, device '%s'\n", __func__,
created, dev->name);