Hi Rob
On 10/11/2016 12:59 AM, Rob Herring wrote:
On Mon, Oct 10, 2016 at 11:07 AM, Ritesh Harjani <riteshh@xxxxxxxxxxxxxx> wrote:
Hi Rob,
Thanks for review.
On 10/10/2016 6:27 PM, Rob Herring wrote:
On Wed, Oct 05, 2016 at 08:10:31PM +0530, Ritesh Harjani wrote:
This adds support for sdhc-msm controllers to get supported
clk-rates from DT. sdhci-msm would need it's own set_clock
ops to be implemented. For this, supported clk-rates needs
to be populated in sdhci_msm_pltfm_data.
Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/mmc/sdhci-msm.txt | 1 +
drivers/mmc/host/sdhci-msm.c | 48
++++++++++++++++++++++
2 files changed, 49 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
index 485483a..6a83b38 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -17,6 +17,7 @@ Required properties:
"iface" - Main peripheral bus clock (PCLK/HCLK - AHB Bus clock)
(required)
"core" - SDC MMC clock (MCLK) (required)
"bus" - SDCC bus voter clock (optional)
+- clk-rates: Array of supported GCC clock frequencies for sdhc, Units -
Hz.
Why can't some combination of assigned-clock-rates and querying the
clock provider for rates be used here?
From what I understood, assigned-clock-rates would only work for setting
some default clock rates for certain clocks by calling
of_clk_set_defaults.
Whereas the requirement here is -
That since SDHC msm directly controls the clk(core clock) at source, it's
sdhci-msm driver needs to know the supported clk-rates by the underlying
platform to configure the nearest floor value supported on this platform
(when the request arrives from the core layer to switch the clock).
Why does clk_round_rate not work for you? That will round down to the
nearest frequency supported.
clk_round_rate will round off to nearest supported "ceil" frequency.
But we require nearest rounded off "floor" frequency.
Hence the table of clk-rates is provided for sdhci-msm.
Minimally this would need unit suffix and either be made common or have
a vendor prefix.
Sure will this work in that case - "qcom-clk-rates"
"qcom,clk-rates", but I'm not yet convinced this is right.
Rob
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