[RFC PATCH] clk: mvebu: armada-xp: Support for MSYS SoC

[chris.packham@alliedtelesis.co.nz (Chris Packham)]

The MSYS SoCs are a range of packet processors with integrated CPUs based
on armada-xp. One difference is that the TCLK frequency is fixed at 200MHz
as opposed to the fixed 250MHz used on armada-xp. The clock-gating options
are a subset of what's available on the armada-xp so this code should be
compatible.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
Hi,

This patch is enough to get the uart clock dividers correct so I get some
output. As far as I've been able to tell there is no way of dynamically
detecting the TCLK frequency.

The core clock frequency and ratio calculations are probably not correct but
for these CPU inside a packet processor systems I'm not sure how much that
actually matter since these systems aren't likely to do any kind of dynamic
frequency scaling.

Thansk,
Chris

 drivers/clk/mvebu/armada-xp.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/mvebu/armada-xp.c b/drivers/clk/mvebu/armada-xp.c
index b309431..9f852f8 100644
--- a/drivers/clk/mvebu/armada-xp.c
+++ b/drivers/clk/mvebu/armada-xp.c
@@ -52,6 +52,12 @@ static u32 __init axp_get_tclk_freq(void __iomem *sar)
 	return 250000000;
 }
 
+/* MSYS TCLK frequency is fixed to 200MHz */
+static u32 __init msys_get_tclk_freq(void __iomem *sar)
+{
+	return 200000000;
+}
+
 static const u32 axp_cpu_freqs[] __initconst = {
 	1000000000,
 	1066000000,
@@ -158,6 +164,14 @@ static const struct coreclk_soc_desc axp_coreclks = {
 	.num_ratios = ARRAY_SIZE(axp_coreclk_ratios),
 };
 
+static const struct coreclk_soc_desc msys_coreclks = {
+	.get_tclk_freq = msys_get_tclk_freq,
+	.get_cpu_freq = axp_get_cpu_freq,
+	.get_clk_ratio = axp_get_clk_ratio,
+	.ratios = axp_coreclk_ratios,
+	.num_ratios = ARRAY_SIZE(axp_coreclk_ratios),
+};
+
 /*
  * Clock Gating Control
  */
@@ -200,9 +214,13 @@ static void __init axp_clk_init(struct device_node *np)
 	struct device_node *cgnp =
 		of_find_compatible_node(NULL, NULL, "marvell,armada-xp-gating-clock");
 
-	mvebu_coreclk_setup(np, &axp_coreclks);
+	if (of_device_is_compatible(np, "marvell,msys-core-clock"))
+		mvebu_coreclk_setup(np, &msys_coreclks);
+	else
+		mvebu_coreclk_setup(np, &axp_coreclks);
 
 	if (cgnp)
 		mvebu_clk_gating_setup(cgnp, axp_gating_desc);
 }
 CLK_OF_DECLARE(axp_clk, "marvell,armada-xp-core-clock", axp_clk_init);
+CLK_OF_DECLARE(msys_clk, "marvell,msys-core-clock", axp_clk_init);
-- 
2.2.0.rc0