clk: samsung: Use clk_hw API for calling clk framework from clk notifiers

clk_notifier_register() documentation states, that the provided notifier
callbacks associated with the notifier must not re-enter into the clk
framework by calling any top-level clk APIs. Fix this by replacing
clk_get_rate() calls with clk_hw_get_rate(), which is safe in this
context.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <snawrocki@kernel.org>

drivers/clk/samsung/clk-cpu.c

@@ -152,7 +152,7 @@ static int exynos_cpuclk_pre_rate_change(struct clk_notifier_data *ndata,
 			struct exynos_cpuclk *cpuclk, void __iomem *base)
 {
 	const struct exynos_cpuclk_cfg_data *cfg_data = cpuclk->cfg;
-	unsigned long alt_prate = clk_get_rate(cpuclk->alt_parent);
+	unsigned long alt_prate = clk_hw_get_rate(cpuclk->alt_parent);
 	unsigned long alt_div = 0, alt_div_mask = DIV_MASK;
 	unsigned long div0, div1 = 0, mux_reg;
 	unsigned long flags;
@@ -280,7 +280,7 @@ static int exynos5433_cpuclk_pre_rate_change(struct clk_notifier_data *ndata,
 			struct exynos_cpuclk *cpuclk, void __iomem *base)
 {
 	const struct exynos_cpuclk_cfg_data *cfg_data = cpuclk->cfg;
-	unsigned long alt_prate = clk_get_rate(cpuclk->alt_parent);
+	unsigned long alt_prate = clk_hw_get_rate(cpuclk->alt_parent);
 	unsigned long alt_div = 0, alt_div_mask = DIV_MASK;
 	unsigned long div0, div1 = 0, mux_reg;
 	unsigned long flags;
@@ -432,7 +432,7 @@ int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx,
 	else
 		cpuclk->clk_nb.notifier_call = exynos_cpuclk_notifier_cb;
 
-	cpuclk->alt_parent = __clk_lookup(alt_parent);
+	cpuclk->alt_parent = __clk_get_hw(__clk_lookup(alt_parent));
 	if (!cpuclk->alt_parent) {
 		pr_err("%s: could not lookup alternate parent %s\n",
 				__func__, alt_parent);

drivers/clk/samsung/clk-cpu.h

@@ -49,7 +49,7 @@ struct exynos_cpuclk_cfg_data {
  */
 struct exynos_cpuclk {
 	struct clk_hw				hw;
-	struct clk				*alt_parent;
+	struct clk_hw				*alt_parent;
 	void __iomem				*ctrl_base;
 	spinlock_t				*lock;
 	const struct exynos_cpuclk_cfg_data	*cfg;