On Tue, Aug 23, 2016 at 4:55 PM, Maxime Ripard
[off-list ref] wrote:

On Mon, Aug 15, 2016 at 04:13:12PM +0800, Chen-Yu Tsai wrote:

quoted

Some clocks on the A31 have fixed pre-dividers on multiple parents.
Add support for them.

Signed-off-by: Chen-Yu Tsai <redacted>
---
Changes since v1:

  - Add field for number of fixed pre-dividers.
---
 drivers/clk/sunxi-ng/ccu-sun8i-h3.c |  9 +++++----
 drivers/clk/sunxi-ng/ccu_mux.c      |  6 ++++--
 drivers/clk/sunxi-ng/ccu_mux.h      | 11 +++++++----
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
index 9af359544110..a01298881991 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c

@@ -184,15 +184,16 @@ static SUNXI_CCU_MP_WITH_MUX(apb2_clk, "apb2", apb2_parents, 0x058,
                           0);

 static const char * const ahb2_parents[] = { "ahb1" , "pll-periph0" };
+static const struct ccu_mux_fixed_prediv ahb2_fixed_predivs[] = {
+     { .index = 1, .div = 2 },
+     { },
+};
 static struct ccu_mux ahb2_clk = {
      .mux            = {
              .shift  = 0,
              .width  = 1,

-             .fixed_prediv   = {
-                     .index  = 1,
-                     .div    = 2,
-             },
+             .fixed_predivs  = ahb2_fixed_predivs,
      },

      .common         = {

diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
index 68b32f168a74..7b17e0c26b01 100644
--- a/drivers/clk/sunxi-ng/ccu_mux.c
+++ b/drivers/clk/sunxi-ng/ccu_mux.c

@@ -20,6 +20,7 @@ void ccu_mux_helper_adjust_parent_for_prediv(struct ccu_common *common,
 {
      u16 prediv = 1;
      u32 reg;
+     int i;

      if (!((common->features & CCU_FEATURE_FIXED_PREDIV) ||
            (common->features & CCU_FEATURE_VARIABLE_PREDIV)))

@@ -32,8 +33,9 @@ void ccu_mux_helper_adjust_parent_for_prediv(struct ccu_common *common,
      }

      if (common->features & CCU_FEATURE_FIXED_PREDIV)
-             if (parent_index == cm->fixed_prediv.index)
-                     prediv = cm->fixed_prediv.div;
+             for (i = 0; i < cm->n_predivs; i++)
+                     if (parent_index == cm->fixed_predivs[i].index)
+                             prediv = cm->fixed_predivs[i].div;

      if (common->features & CCU_FEATURE_VARIABLE_PREDIV)
              if (parent_index == cm->variable_prediv.index) {

diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
index f0078de78712..5308b41da22a 100644
--- a/drivers/clk/sunxi-ng/ccu_mux.h
+++ b/drivers/clk/sunxi-ng/ccu_mux.h

@@ -5,15 +5,18 @@

 #include "ccu_common.h"

+struct ccu_mux_fixed_prediv {
+     u8      index;
+     u16     div;
+};
+
 struct ccu_mux_internal {
      u8              shift;
      u8              width;
      const u8        *table;

-     struct {
-             u8      index;
-             u16     div;
-     } fixed_prediv;
+     const struct ccu_mux_fixed_prediv       *fixed_predivs;
+     u8              n_predivs;

I don't think you're using it anywhere (at least you don't define it
in ahb2_clk, and the extra item in the array will introduce an
off-by-one error.

The truth is I forgot to update the change in ccu-sun8i-h3.c
It is used correctly in the subsequent a31 patch. Sorry.

I'm not sure what you mean by the off-by-one error though. IIRC
we initialize the structure using named fields.


ChenYu

Thanks!
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com