Thread (10 messages) 10 messages, 4 authors, 2014-02-18

Re: [PATCH v4 1/5] clk: sunxi: Add support for PLL6 on the A31

From: Mike Turquette <hidden>
Date: 2014-02-05 14:51:57
Also in: linux-arm-kernel, linux-spi, lkml

Quoting Maxime Ripard (2014-02-05 05:05:03)
The A31 has a slightly different PLL6 clock. Add support for this new clock in
our driver.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Looks good to me.

Regards,
Mike
quoted hunk ↗ jump to hunk
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 drivers/clk/sunxi/clk-sunxi.c                     | 45 +++++++++++++++++++++++
 2 files changed, 46 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index c2cb762..954845c 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -11,6 +11,7 @@ Required properties:
        "allwinner,sun6i-a31-pll1-clk" - for the main PLL clock on A31
        "allwinner,sun4i-pll5-clk" - for the PLL5 clock
        "allwinner,sun4i-pll6-clk" - for the PLL6 clock
+       "allwinner,sun6i-a31-pll6-clk" - for the PLL6 clock on A31
        "allwinner,sun4i-cpu-clk" - for the CPU multiplexer clock
        "allwinner,sun4i-axi-clk" - for the AXI clock
        "allwinner,sun4i-axi-gates-clk" - for the AXI gates
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index abb6c5a..0c05c2d 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -249,7 +249,38 @@ static void sun4i_get_pll5_factors(u32 *freq, u32 parent_rate,
        *n = DIV_ROUND_UP(div, (*k+1));
 }
 
+/**
+ * sun6i_a31_get_pll6_factors() - calculates n, k factors for A31 PLL6
+ * PLL6 rate is calculated as follows
+ * rate = parent_rate * n * (k + 1) / 2
+ * parent_rate is always 24Mhz
+ */
+
+static void sun6i_a31_get_pll6_factors(u32 *freq, u32 parent_rate,
+                                      u8 *n, u8 *k, u8 *m, u8 *p)
+{
+       u8 div;
+
+       /*
+        * We always have 24MHz / 2, so we can just say that our
+        * parent clock is 12MHz.
+        */
+       parent_rate = parent_rate / 2;
+
+       /* Normalize value to a parent_rate multiple (24M / 2) */
+       div = *freq / parent_rate;
+       *freq = parent_rate * div;
+
+       /* we were called to round the frequency, we can now return */
+       if (n == NULL)
+               return;
+
+       *k = div / 32;
+       if (*k > 3)
+               *k = 3;
 
+       *n = DIV_ROUND_UP(div, (*k+1));
+}
 
 /**
  * sun4i_get_apb1_factors() - calculates m, p factors for APB1
@@ -416,6 +447,13 @@ static struct clk_factors_config sun4i_pll5_config = {
        .kwidth = 2,
 };
 
+static struct clk_factors_config sun6i_a31_pll6_config = {
+       .nshift = 8,
+       .nwidth = 5,
+       .kshift = 4,
+       .kwidth = 2,
+};
+
 static struct clk_factors_config sun4i_apb1_config = {
        .mshift = 0,
        .mwidth = 5,
@@ -457,6 +495,12 @@ static const struct factors_data sun4i_pll5_data __initconst = {
        .getter = sun4i_get_pll5_factors,
 };
 
+static const struct factors_data sun6i_a31_pll6_data __initconst = {
+       .enable = 31,
+       .table = &sun6i_a31_pll6_config,
+       .getter = sun6i_a31_get_pll6_factors,
+};
+
 static const struct factors_data sun4i_apb1_data __initconst = {
        .table = &sun4i_apb1_config,
        .getter = sun4i_get_apb1_factors,
@@ -972,6 +1016,7 @@ free_clkdata:
 static const struct of_device_id clk_factors_match[] __initconst = {
        {.compatible = "allwinner,sun4i-pll1-clk", .data = &sun4i_pll1_data,},
        {.compatible = "allwinner,sun6i-a31-pll1-clk", .data = &sun6i_a31_pll1_data,},
+       {.compatible = "allwinner,sun6i-a31-pll6-clk", .data = &sun6i_a31_pll6_data,},
        {.compatible = "allwinner,sun4i-apb1-clk", .data = &sun4i_apb1_data,},
        {.compatible = "allwinner,sun4i-mod0-clk", .data = &sun4i_mod0_data,},
        {.compatible = "allwinner,sun7i-a20-out-clk", .data = &sun7i_a20_out_data,},
-- 
1.8.4.2
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