[PATCH v1 2/3] spi: kirkwood: prevent configuring speed exceeding max controller freq

[Stefan Roese]

From: Marcin Wojtas <mw at semihalf.com>

This patch adds a limitation in the kirkwood_spi driver
set_speed hook, which prevents setting too high transfer
speed.

Signed-off-by: Marcin Wojtas <mw at semihalf.com>
Reviewed-by: Kostya Porotchkin <kostap at marvell.com>
Tested-by: Kostya Porotchkin <kostap at marvell.com>
Signed-off-by: Stefan Roese <sr at denx.de>
---

 drivers/spi/kirkwood_spi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/spi/kirkwood_spi.c b/drivers/spi/kirkwood_spi.c
index 3dc62f351a06..063ed5f35a3a 100644
--- a/drivers/spi/kirkwood_spi.c
+++ b/drivers/spi/kirkwood_spi.c
@@ -110,10 +110,17 @@ static int _spi_xfer(struct kwspi_registers *reg, unsigned int bitlen,
 static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
 {
 	struct mvebu_spi_plat *plat = dev_get_plat(bus);
+	struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
 	struct kwspi_registers *reg = plat->spireg;
 	u32 data, divider;
 	unsigned int spr, sppr;
 
+	if (hz > spi->max_hz) {
+		debug("%s: limit speed to the max_hz of the bus %d\n",
+		      __func__, spi->max_hz);
+		hz = spi->max_hz;
+	}
+
 	/*
 	 * Calculate spi clock prescaller using max_hz.
 	 * SPPR is SPI Baud Rate Pre-selection, it holds bits 5 and 7:6 in
-- 
2.31.1