Quoting Tomasz Figa (2013-07-27 05:41:05)

Hi Mike,

On Tuesday 23 of July 2013 01:49:18 Tomasz Figa wrote:

quoted

Some platforms have read-only clock muxes that are preconfigured at
reset and cannot be changed at runtime. This patch extends mux clock
driver to allow handling such read-only muxes by adding new
CLK_MUX_READ_ONLY mux flag.

Signed-off-by: Tomasz Figa <redacted>
---
 drivers/clk/clk-mux.c        | 10 +++++++++-
 include/linux/clk-provider.h |  2 ++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 614444c..92f1a1b 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c

@@ -107,6 +107,11 @@ const struct clk_ops clk_mux_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_mux_ops);

+const struct clk_ops clk_mux_ro_ops = {
+     .get_parent = clk_mux_get_parent,
+};
+EXPORT_SYMBOL_GPL(clk_mux_ro_ops);
+
 struct clk *clk_register_mux_table(struct device *dev, const char

*name, const char **parent_names, u8 num_parents, unsigned long flags,
void __iomem *reg, u8 shift, u32 mask,

@@ -133,7 +138,10 @@ struct clk *clk_register_mux_table(struct device

*dev, const char *name, }

      init.name = name;
-     init.ops = &clk_mux_ops;
+     if (clk_mux_flags & CLK_MUX_READ_ONLY)
+             init.ops = &clk_mux_ro_ops;
+     else
+             init.ops = &clk_mux_ops;
      init.flags = flags | CLK_IS_BASIC;
      init.parent_names = parent_names;
      init.num_parents = num_parents;

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 1ec14a7..9487b96 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h

@@ -327,8 +327,10 @@ struct clk_mux {
 #define CLK_MUX_INDEX_ONE            BIT(0)
 #define CLK_MUX_INDEX_BIT            BIT(1)
 #define CLK_MUX_HIWORD_MASK          BIT(2)
+#define CLK_MUX_READ_ONLY    BIT(3) /* mux setting cannot be changed */

 extern const struct clk_ops clk_mux_ops;
+extern const struct clk_ops clk_mux_ro_ops;

 struct clk *clk_register_mux(struct device *dev, const char *name,
              const char **parent_names, u8 num_parents, unsigned long 

flags,

What do you think about this?

Looks good to me. This makes sense for OMAP's sys_clkin clock, probably
a common pattern.

Acked-by: Mike Turquette <redacted>

Best regards,
Tomasz