From e2e95e5e25421fbef499e21bf94a5339701f9a99 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Thu, 10 Jun 2021 14:00:00 +0200 Subject: [PATCH] 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 Cc: Jagan Teki Cc: Patrick Delaunay --- drivers/spi/spi-uclass.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) 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);