2017-01-13 20:25 GMT+01:00 David Lechner [off-list ref]:

On 01/13/2017 06:37 AM, Bartosz Golaszewski wrote:

quoted

Add DT bindings for the TI DA850 AHCI SATA controller.

Signed-off-by: Bartosz Golaszewski <redacted>
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 .../devicetree/bindings/ata/ahci-da850.txt          | 21
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 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ata/ahci-da850.txt

diff --git a/Documentation/devicetree/bindings/ata/ahci-da850.txt

b/Documentation/devicetree/bindings/ata/ahci-da850.txt
new file mode 100644
index 0000000..d07c241

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+++ b/Documentation/devicetree/bindings/ata/ahci-da850.txt

@@ -0,0 +1,21 @@
+Device tree binding for the TI DA850 AHCI SATA Controller
+---------------------------------------------------------
+
+Required properties:
+  - compatible: must be "ti,da850-ahci"
+  - reg: physical base addresses and sizes of the controller's register

areas
+  - interrupts: interrupt specifier (refer to the interrupt binding)
+
+Optional properties:
+  - clocks: clock specifier (refer to the common clock binding)
+  - da850,clk_multiplier: the multiplier for the reference clock needed
+                          for 1.5GHz PLL output

A clock multiplier property seems redundant if you are specifying a clock.
It should be possible to get the rate from the clock to determine which
multiplier is needed.

I probably should have named it differently. This is not a multiplier
of a clock derived from PLL0 or PLL1. Instead it's a value set by
writing to the Port PHY Control Register (MPY bits) of the SATA
controller that configures the multiplier for the external low-jitter
clock. On the lcdk the signals (REFCLKP, REFCLKN) are provided by
CDCM61001 (SATA OSCILLATOR component on the schematics).

I'll find a better name and comment the property accordingly.

FYI: the da850 platform does not use the common clock framework, so I
don't specify the clock property on the sata node in the device tree.
Instead I add the clock lookup entry in patch [01/10]. This is
transparent for AHCI which can get the clock as usual by calling
clk_get() in ahci_platform_get_resources().

Thanks,
Bartosz Golaszewski