clk: imx: Pass CCM udevice into clk_register_composite()

Pass the clock controller udevice into clk_register_composite(),
so it can be passed further to any registered composite clocks
and used for look up of parent clock referenced in DT "clocks"
and "clock-names" properties by phandle and name pair.

Use the clock controller udevice in imx8m_clk_mux_set_parent()
to perform accurate look up of parent clock referenced in the
CCM driver by name. If the clock name that is being looked up
matches one of the names listed in the clock controller DT node
"clock-names" array property, then the offset of the name is
looked up in the "clocks" DT property and the phandle at that
offset is resolved to the parent clock udevice. The test to
determine whether a particular driver instance registered with
clock uclass matches the parent clock is done by comparing the
OF nodes of the clock registered with clock uclass and parent
clock resolved from the phandle.

Example:

drivers/clk/imx/clk-imx8mm.c:
static const char * const imx8mm_a53_sels[] = {"osc_24m", "arm_pll_out", ...
                                      _____________|
arch/arm/dts/imx8mm.dtsi:            |
clk: clock-controller@30380000 {     v
        clock-names = "osc_32k", "osc_24m", ...
	                           |
				   v
        clocks = <&osc_32k>, <&osc_24m>, ...
};          _______________________|
...        |
/ {        v
        osc_24m: clock-osc-24m {
                compatible = "fixed-clock";
...
};

Signed-off-by: Marek Vasut <marex@denx.de>
Reported-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Tested-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Adam Ford <aford173@gmail.com> # imx8mp-beacon

diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
index 9e3b51917673ff9e6464b831c1651fce4382340d..207224b13208d3f69db85cd348bb688efb9f1541 100644 (file)
--- a/drivers/clk/clk-composite.c
+++ b/drivers/clk/clk-composite.c
@@ -155,6 +155,8 @@ struct clk *clk_register_composite(struct udevice *dev, const char *name,
                goto err;
        }
 
+       composite->dev = dev;
+
        if (composite->mux)
                composite->mux->dev = clk->dev;
        if (composite->rate)

diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
index 14c5b92939ccf080774fdb3188e699a8db1b8b17..e1a3c0af308baf8a0c128e7fe9dbba6255a46eac 100644 (file)
--- a/drivers/clk/imx/clk-composite-8m.c
+++ b/drivers/clk/imx/clk-composite-8m.c
@@ -116,14 +116,42 @@ static const struct clk_ops imx8m_clk_composite_divider_ops = {
        .set_rate = imx8m_clk_composite_divider_set_rate,
 };
 
+static int imx8m_clk_mux_fetch_parent_index(struct udevice *cdev, struct clk *clk, struct clk *parent)
+{
+       struct clk_mux *mux = to_clk_mux(clk);
+       struct clk cclk;
+       int ret;
+       int i;
+
+       if (!parent)
+               return -EINVAL;
+
+       for (i = 0; i < mux->num_parents; i++) {
+               ret = clk_get_by_name(cdev, mux->parent_names[i], &cclk);
+               if (!ret && ofnode_equal(dev_ofnode(parent->dev), dev_ofnode(cclk.dev)))
+                       return i;
+
+               if (!strcmp(parent->dev->name, mux->parent_names[i]))
+                       return i;
+               if (!strcmp(parent->dev->name,
+                           clk_resolve_parent_clk(clk->dev,
+                                                  mux->parent_names[i])))
+                       return i;
+       }
+
+       return -EINVAL;
+}
+
+
 static int imx8m_clk_mux_set_parent(struct clk *clk, struct clk *parent)
 {
        struct clk_mux *mux = to_clk_mux(clk);
+       struct clk_composite *composite = (struct clk_composite *)clk->data;
        int index;
        u32 val;
        u32 reg;
 
-       index = clk_mux_fetch_parent_index(clk, parent);
+       index = imx8m_clk_mux_fetch_parent_index(composite->dev, clk, parent);
        if (index < 0) {
                log_err("Could not fetch index\n");
                return index;

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 5ea2171492e1f5d0234da07ed2d68c03cbb08c5e..267757939e0e98f9a804d0332ad7d329be763076 100644 (file)
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -219,6 +219,8 @@ struct clk_composite {
        const struct clk_ops    *mux_ops;
        const struct clk_ops    *rate_ops;
        const struct clk_ops    *gate_ops;
+
+       struct udevice *dev;
 };
 
 #define to_clk_composite(_clk) container_of(_clk, struct clk_composite, clk)