[PATCH 1/3] clk: mux: Add regmap support for simple mux

2015-05-29 8:40 GMT+02:00 Sascha Hauer [off-list ref]:

On Thu, May 28, 2015 at 08:41:46PM +0200, Matthias Brugger wrote:

quoted

Some devices like SoCs from Mediatek need to use the clock muxes
through a regmap interface.
This patch adds regmap support for simple the simple multiplexer
clock code.

Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
---
 drivers/clk/clk-mux.c        | 103 ++++++++++++++++++++++++++++++++++++++-----
 include/linux/clk-provider.h |  40 +++++++++++++++++
 2 files changed, 132 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 1fa2a8d..c7c692a 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c

@@ -29,6 +29,26 @@

 #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)

+static void clk_mux_writel(struct clk_mux *mux, u32 val)
+{
+     if (mux->flags && CLK_MUX_USE_REGMAP)
+             regmap_write(mux->regmap, mux->offset, val);
+     else
+             clk_writel(val, mux->reg);
+}
+
+static u32 clk_mux_readl(struct clk_mux *mux)
+{
+     u32 val;
+
+     if (mux->flags && CLK_MUX_USE_REGMAP)
+             regmap_read(mux->regmap, mux->offset, &val);
+     else
+             val = clk_readl(mux->reg);
+
+     return val;
+}
+
 static u8 clk_mux_get_parent(struct clk_hw *hw)
 {
      struct clk_mux *mux = to_clk_mux(hw);

@@ -42,7 +62,10 @@ static u8 clk_mux_get_parent(struct clk_hw *hw)
       * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
       * val = 0x4 really means "bit 2, index starts at bit 0"
       */
-     val = clk_readl(mux->reg) >> mux->shift;
+
+     val = clk_mux_readl(mux);
+
+     val >>= mux->shift;
      val &= mux->mask;

      if (mux->table) {

@@ -89,11 +112,11 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
      if (mux->flags & CLK_MUX_HIWORD_MASK) {
              val = mux->mask << (mux->shift + 16);
      } else {
-             val = clk_readl(mux->reg);
+             val = clk_mux_readl(mux);
              val &= ~(mux->mask << mux->shift);
      }
      val |= index << mux->shift;
-     clk_writel(val, mux->reg);
+     clk_mux_writel(mux, val);

With regmap the register lock is inside the regmap, you must hold it
during read/modify/write operations which means you have to use
regmap_update_bits rather than regmap_read followed by regmap_write.

Fixed in next version.
Thanks for reviewing.

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