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| author | Sifan Naeem <sifan.naeem@imgtec.com> | 2015-06-18 14:27:12 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-07-07 13:56:36 +0200 |
| commit | 93e3a9e9993ef018522b7005d97d8124b7e73385 (patch) | |
| tree | 49d514d05357faffd6c64e54757e59da536d06d3 | |
| parent | Linux 4.2-rc1 (diff) | |
| download | linux-93e3a9e9993ef018522b7005d97d8124b7e73385.tar.xz linux-93e3a9e9993ef018522b7005d97d8124b7e73385.zip | |
spi: img-spfi: check for max speed supported by the spfi block
Maximum speed supported by spfi is limited to 1/4 of the spfi clock.
But in some SoCs the maximum speed supported by the spfi block can
be limited to less than 1/4 of the spfi clock. In such cases we have
to define the limit in the device tree so that the driver can pick
it up.
Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-img-spfi.txt | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-img-spfi.c | 14 |
2 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-img-spfi.txt b/Documentation/devicetree/bindings/spi/spi-img-spfi.txt index e02fbf18c82c..494db6012d02 100644 --- a/Documentation/devicetree/bindings/spi/spi-img-spfi.txt +++ b/Documentation/devicetree/bindings/spi/spi-img-spfi.txt @@ -21,6 +21,7 @@ Required properties: Optional properties: - img,supports-quad-mode: Should be set if the interface supports quad mode SPI transfers. +- spfi-max-frequency: Maximum speed supported by the spfi block. Example: diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c index 788e2b176a4f..f31d792a4662 100644 --- a/drivers/spi/spi-img-spfi.c +++ b/drivers/spi/spi-img-spfi.c @@ -546,6 +546,7 @@ static int img_spfi_probe(struct platform_device *pdev) struct img_spfi *spfi; struct resource *res; int ret; + u32 max_speed_hz; master = spi_alloc_master(&pdev->dev, sizeof(*spfi)); if (!master) @@ -610,6 +611,19 @@ static int img_spfi_probe(struct platform_device *pdev) master->max_speed_hz = clk_get_rate(spfi->spfi_clk) / 4; master->min_speed_hz = clk_get_rate(spfi->spfi_clk) / 512; + /* + * Maximum speed supported by spfi is limited to the lower value + * between 1/4 of the SPFI clock or to "spfi-max-frequency" + * defined in the device tree. + * If no value is defined in the device tree assume the maximum + * speed supported to be 1/4 of the SPFI clock. + */ + if (!of_property_read_u32(spfi->dev->of_node, "spfi-max-frequency", + &max_speed_hz)) { + if (master->max_speed_hz > max_speed_hz) + master->max_speed_hz = max_speed_hz; + } + master->setup = img_spfi_setup; master->cleanup = img_spfi_cleanup; master->transfer_one = img_spfi_transfer_one; |