rockchip: clock: Add a function to find a clock by ID

The current approach of using uclass_get_device() is error-prone. Another
clock (for example a fixed-clock) may cause it to break. Add a function that
does a proper search.

Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 34 insertions, 2 deletions

diff --git a/arch/arm/include/asm/arch-rockchip/clock.h b/arch/arm/include/asm/arch-rockchip/clock.h
index 8a0376c..a9ea268 100644
--- a/arch/arm/include/asm/arch-rockchip/clock.h
+++ b/arch/arm/include/asm/arch-rockchip/clock.h
@@ -62,4 +62,16 @@ static inline u32 clk_get_divisor(ulong input_rate, uint output_rate)
  */
 void *rockchip_get_cru(void);
 
+/**
+ * rkclk_get_clk() - get a pointer to a given clock
+ *
+ * This is an internal function - use outside the clock subsystem indicates
+ * that work is needed!
+ *
+ * @clk_id:	Clock requested
+ * @devp:	Returns a pointer to that clock
+ * @return 0 if OK, -ve on error
+ */
+int rkclk_get_clk(enum rk_clk_id clk_id, struct udevice **devp);
+
 #endif
diff --git a/drivers/clk/clk_rk3288.c b/drivers/clk/clk_rk3288.c
index df5c38c..fdc5347 100644
--- a/drivers/clk/clk_rk3288.c
+++ b/drivers/clk/clk_rk3288.c
@@ -15,7 +15,9 @@
 #include <asm/arch/grf_rk3288.h>
 #include <asm/arch/hardware.h>
 #include <dt-bindings/clock/rk3288-cru.h>
+#include <dm/device-internal.h>
 #include <dm/lists.h>
+#include <dm/uclass-internal.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -139,6 +141,24 @@ static const struct pll_div apll_init_cfg = PLL_DIVISORS(APLL_HZ, 1, 1);
 static const struct pll_div gpll_init_cfg = PLL_DIVISORS(GPLL_HZ, 2, 2);
 static const struct pll_div cpll_init_cfg = PLL_DIVISORS(CPLL_HZ, 1, 2);
 
+int rkclk_get_clk(enum rk_clk_id clk_id, struct udevice **devp)
+{
+	struct udevice *dev;
+
+	for (uclass_find_first_device(UCLASS_CLK, &dev);
+	     dev;
+	     uclass_find_next_device(&dev)) {
+		struct rk3288_clk_plat *plat = dev_get_platdata(dev);
+
+		if (plat->clk_id == clk_id) {
+			*devp = dev;
+			return device_probe(dev);
+		}
+	}
+
+	return -ENODEV;
+}
+
 static int rkclk_set_pll(struct rk3288_cru *cru, enum rk_clk_id clk_id,
 			 const struct pll_div *div)
 {
@@ -515,7 +535,7 @@ static ulong rk3288_get_periph_rate(struct udevice *dev, int periph)
 	ulong new_rate, gclk_rate;
 	int ret;
 
-	ret = uclass_get_device(UCLASS_CLK, CLK_GENERAL, &gclk);
+	ret = rkclk_get_clk(CLK_GENERAL, &gclk);
 	if (ret)
 		return ret;
 	gclk_rate = clk_get_rate(gclk);
@@ -551,7 +571,7 @@ static ulong rk3288_set_periph_rate(struct udevice *dev, int periph, ulong rate)
 	ulong new_rate, gclk_rate;
 	int ret;
 
-	ret = uclass_get_device(UCLASS_CLK, CLK_GENERAL, &gclk);
+	ret = rkclk_get_clk(CLK_GENERAL, &gclk);
 	if (ret)
 		return ret;
 	gclk_rate = clk_get_rate(gclk);