[PATCH v2 09/12] clk: boston: Allow to get regmap from parent device

[Jiaxun Yang]

In upstream devicetree, clk_boston is a child of syscon node
and there is no "regmap" property for clk_boston node.

Try to check parent device first to look for syscon.

Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
v2: Move syscon_get_regmap to probe
---
 drivers/clk/clk_boston.c | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/clk_boston.c b/drivers/clk/clk_boston.c
index 030ff7cc58ec..1985bb0ec334 100644
--- a/drivers/clk/clk_boston.c
+++ b/drivers/clk/clk_boston.c
@@ -12,6 +12,7 @@
 #include <linux/printk.h>
 
 struct clk_boston {
+       struct udevice *syscon;
        struct regmap *regmap;
 };
 
@@ -58,23 +59,33 @@ const struct clk_ops clk_boston_ops = {
        .get_rate = clk_boston_get_rate,
 };
 
-static int clk_boston_of_to_plat(struct udevice *dev)
+static int clk_boston_probe(struct udevice *dev)
 {
        struct clk_boston *state = dev_get_plat(dev);
-       struct udevice *syscon;
-       int err;
 
-       err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
-                                          "regmap", &syscon);
-       if (err) {
-               pr_err("unable to find syscon device\n");
-               return err;
+       state->regmap = syscon_get_regmap(state->syscon);
+       if (IS_ERR(state->regmap)) {
+               pr_err("unable to find regmap\n");
+               return PTR_ERR(state->regmap);
        }
 
-       state->regmap = syscon_get_regmap(syscon);
-       if (!state->regmap) {
-               pr_err("unable to find regmap\n");
-               return -ENODEV;
+       return 0;
+}
+
+static int clk_boston_of_to_plat(struct udevice *dev)
+{
+       struct clk_boston *state = dev_get_plat(dev);
+       int err;
+
+       if (dev->parent && device_get_uclass_id(dev->parent) == UCLASS_SYSCON) {
+               state->syscon = dev->parent;
+       } else {
+               err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
+                                                  "regmap", &state->syscon);
+               if (err) {
+                       pr_err("unable to find syscon device\n");
+                       return err;
+               }
        }
 
        return 0;
@@ -92,6 +103,8 @@ U_BOOT_DRIVER(clk_boston) = {
        .id = UCLASS_CLK,
        .of_match = clk_boston_match,
        .of_to_plat = clk_boston_of_to_plat,
+       .probe = clk_boston_probe,
        .plat_auto      = sizeof(struct clk_boston),
        .ops = &clk_boston_ops,
+       .flags = DM_FLAG_PRE_RELOC,
 };

-- 
2.34.1