diff options
| author | Marek Vasut <marex@denx.de> | 2021-06-10 14:00:00 +0200 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2021-06-30 08:06:30 -0400 |
| commit | e2e95e5e25421fbef499e21bf94a5339701f9a99 (patch) | |
| tree | 73a4d5a38a19c321a867ae6466dc6b5c689bada7 /drivers/spi | |
| parent | 605cbcb0a43cef8f987a736d0f5991a9db314562 (diff) | |
spi: Update speed/mode on 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>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-uclass.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c index ee30110b56..d867b27806 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); |