clk: samsung: Use cached clk_hws instead of __clk_lookup() calls

For the CPU clock registration two parent clocks are required, these
are now being passed as struct clk_hw pointers, rather than by the
global scope names. That allows us to avoid  __clk_lookup() calls
and simplifies a bit the CPU clock registration function.
While at it drop unneeded extern keyword in the function declaration.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://lore.kernel.org/r/20200826171529.23618-3-s.nawrocki@samsung.com
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

drivers/clk/samsung/clk-cpu.c

@@ -401,26 +401,34 @@ static int exynos5433_cpuclk_notifier_cb(struct notifier_block *nb,
 
 /* helper function to register a CPU clock */
 int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx,
-		unsigned int lookup_id, const char *name, const char *parent,
+		unsigned int lookup_id, const char *name,
-		const char *alt_parent, unsigned long offset,
+		const struct clk_hw *parent, const struct clk_hw *alt_parent,
-		const struct exynos_cpuclk_cfg_data *cfg,
+		unsigned long offset, const struct exynos_cpuclk_cfg_data *cfg,
 		unsigned long num_cfgs, unsigned long flags)
 {
 	struct exynos_cpuclk *cpuclk;
 	struct clk_init_data init;
-	struct clk *parent_clk;
+	const char *parent_name;
 	int ret = 0;
 
+	if (IS_ERR(parent) || IS_ERR(alt_parent)) {
+		pr_err("%s: invalid parent clock(s)\n", __func__);
+		return -EINVAL;
+	}
+
 	cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL);
 	if (!cpuclk)
 		return -ENOMEM;
 
+	parent_name = clk_hw_get_name(parent);
+
 	init.name = name;
 	init.flags = CLK_SET_RATE_PARENT;
-	init.parent_names = &parent;
+	init.parent_names = &parent_name;
 	init.num_parents = 1;
 	init.ops = &exynos_cpuclk_clk_ops;
 
+	cpuclk->alt_parent = alt_parent;
 	cpuclk->hw.init = &init;
 	cpuclk->ctrl_base = ctx->reg_base + offset;
 	cpuclk->lock = &ctx->lock;
@@ -430,23 +438,8 @@ 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_get_hw(__clk_lookup(alt_parent));
-	if (!cpuclk->alt_parent) {
-		pr_err("%s: could not lookup alternate parent %s\n",
-				__func__, alt_parent);
-		ret = -EINVAL;
-		goto free_cpuclk;
-	}
 
-	parent_clk = __clk_lookup(parent);
+	ret = clk_notifier_register(parent->clk, &cpuclk->clk_nb);
-	if (!parent_clk) {
-		pr_err("%s: could not lookup parent clock %s\n",
-				__func__, parent);
-		ret = -EINVAL;
-		goto free_cpuclk;
-	}
-
-	ret = clk_notifier_register(parent_clk, &cpuclk->clk_nb);
 	if (ret) {
 		pr_err("%s: failed to register clock notifier for %s\n",
 				__func__, name);
@@ -471,7 +464,7 @@ int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx,
 free_cpuclk_data:
 	kfree(cpuclk->cfg);
 unregister_clk_nb:
-	clk_notifier_unregister(parent_clk, &cpuclk->clk_nb);
+	clk_notifier_unregister(parent->clk, &cpuclk->clk_nb);
 free_cpuclk:
 	kfree(cpuclk);
 	return ret;

drivers/clk/samsung/clk-cpu.h

@@ -46,7 +46,7 @@ struct exynos_cpuclk_cfg_data {
  */
 struct exynos_cpuclk {
 	struct clk_hw				hw;
-	struct clk_hw				*alt_parent;
+	const struct clk_hw			*alt_parent;
 	void __iomem				*ctrl_base;
 	spinlock_t				*lock;
 	const struct exynos_cpuclk_cfg_data	*cfg;
@@ -62,9 +62,9 @@ struct exynos_cpuclk {
 #define CLK_CPU_HAS_E5433_REGS_LAYOUT	(1 << 2)
 };
 
-extern int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx,
+int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx,
 			unsigned int lookup_id, const char *name,
-			const char *parent, const char *alt_parent,
+			const struct clk_hw *parent, const struct clk_hw *alt_parent,
 			unsigned long offset,
 			const struct exynos_cpuclk_cfg_data *cfg,
 			unsigned long num_cfgs, unsigned long flags);

drivers/clk/samsung/clk-exynos3250.c

@@ -808,14 +808,16 @@ static const struct exynos_cpuclk_cfg_data e3250_armclk_d[] __initconst = {
 static void __init exynos3250_cmu_init(struct device_node *np)
 {
 	struct samsung_clk_provider *ctx;
+	struct clk_hw **hws;
 
 	ctx = samsung_cmu_register_one(np, &cmu_info);
 	if (!ctx)
 		return;
 
+	hws = ctx->clk_data.hws;
 	exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
-			mout_core_p[0], mout_core_p[1], 0x14200,
+			hws[CLK_MOUT_APLL], hws[CLK_MOUT_MPLL_USER_C],
-			e3250_armclk_d, ARRAY_SIZE(e3250_armclk_d),
+			0x14200, e3250_armclk_d, ARRAY_SIZE(e3250_armclk_d),
 			CLK_CPU_HAS_DIV1);
 
 	exynos3_core_down_clock(ctx->reg_base);

drivers/clk/samsung/clk-exynos4.c

@@ -1233,6 +1233,8 @@ static void __init exynos4_clk_init(struct device_node *np,
 				    enum exynos4_soc soc)
 {
 	struct samsung_clk_provider *ctx;
+	struct clk_hw **hws;
+
 	exynos4_soc = soc;
 
 	reg_base = of_iomap(np, 0);
@@ -1240,6 +1242,7 @@ static void __init exynos4_clk_init(struct device_node *np,
 		panic("%s: failed to map registers\n", __func__);
 
 	ctx = samsung_clk_init(np, reg_base, CLK_NR_CLKS);
+	hws = ctx->clk_data.hws;
 
 	samsung_clk_of_register_fixed_ext(ctx, exynos4_fixed_rate_ext_clks,
 			ARRAY_SIZE(exynos4_fixed_rate_ext_clks),
@@ -1302,7 +1305,7 @@ static void __init exynos4_clk_init(struct device_node *np,
 			exynos4210_fixed_factor_clks,
 			ARRAY_SIZE(exynos4210_fixed_factor_clks));
 		exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
-			mout_core_p4210[0], mout_core_p4210[1], 0x14200,
+			hws[CLK_MOUT_APLL], hws[CLK_SCLK_MPLL], 0x14200,
 			e4210_armclk_d, ARRAY_SIZE(e4210_armclk_d),
 			CLK_CPU_NEEDS_DEBUG_ALT_DIV | CLK_CPU_HAS_DIV1);
 	} else {
@@ -1317,7 +1320,7 @@ static void __init exynos4_clk_init(struct device_node *np,
 			ARRAY_SIZE(exynos4x12_fixed_factor_clks));
 
 		exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
-			mout_core_p4x12[0], mout_core_p4x12[1], 0x14200,
+			hws[CLK_MOUT_APLL], hws[CLK_MOUT_MPLL_USER_C], 0x14200,
 			e4412_armclk_d, ARRAY_SIZE(e4412_armclk_d),
 			CLK_CPU_NEEDS_DEBUG_ALT_DIV | CLK_CPU_HAS_DIV1);
 	}

drivers/clk/samsung/clk-exynos5250.c

@@ -782,6 +782,7 @@ static void __init exynos5250_clk_init(struct device_node *np)
 {
 	struct samsung_clk_provider *ctx;
 	unsigned int tmp;
+	struct clk_hw **hws;
 
 	if (np) {
 		reg_base = of_iomap(np, 0);
@@ -792,6 +793,7 @@ static void __init exynos5250_clk_init(struct device_node *np)
 	}
 
 	ctx = samsung_clk_init(np, reg_base, CLK_NR_CLKS);
+	hws = ctx->clk_data.hws;
 
 	samsung_clk_of_register_fixed_ext(ctx, exynos5250_fixed_rate_ext_clks,
 			ARRAY_SIZE(exynos5250_fixed_rate_ext_clks),
@@ -821,7 +823,7 @@ static void __init exynos5250_clk_init(struct device_node *np)
 	samsung_clk_register_gate(ctx, exynos5250_gate_clks,
 			ARRAY_SIZE(exynos5250_gate_clks));
 	exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
-			mout_cpu_p[0], mout_cpu_p[1], 0x200,
+			hws[CLK_MOUT_APLL], hws[CLK_MOUT_MPLL], 0x200,
 			exynos5250_armclk_d, ARRAY_SIZE(exynos5250_armclk_d),
 			CLK_CPU_HAS_DIV1);
 

drivers/clk/samsung/clk-exynos5420.c

@@ -1574,6 +1574,7 @@ static void __init exynos5x_clk_init(struct device_node *np,
 	exynos5x_soc = soc;
 
 	ctx = samsung_clk_init(np, reg_base, CLK_NR_CLKS);
+	hws = ctx->clk_data.hws;
 
 	samsung_clk_of_register_fixed_ext(ctx, exynos5x_fixed_rate_ext_clks,
 			ARRAY_SIZE(exynos5x_fixed_rate_ext_clks),
@@ -1625,15 +1626,15 @@ static void __init exynos5x_clk_init(struct device_node *np,
 
 	if (soc == EXYNOS5420) {
 		exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
-			mout_cpu_p[0], mout_cpu_p[1], 0x200,
+			hws[CLK_MOUT_APLL], hws[CLK_MOUT_MSPLL_CPU], 0x200,
 			exynos5420_eglclk_d, ARRAY_SIZE(exynos5420_eglclk_d), 0);
 	} else {
 		exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk",
-			mout_cpu_p[0], mout_cpu_p[1], 0x200,
+			hws[CLK_MOUT_APLL], hws[CLK_MOUT_MSPLL_CPU], 0x200,
 			exynos5800_eglclk_d, ARRAY_SIZE(exynos5800_eglclk_d), 0);
 	}
 	exynos_register_cpu_clock(ctx, CLK_KFC_CLK, "kfcclk",
-		mout_kfc_p[0], mout_kfc_p[1], 0x28200,
+		hws[CLK_MOUT_KPLL], hws[CLK_MOUT_MSPLL_KFC],  0x28200,
 		exynos5420_kfcclk_d, ARRAY_SIZE(exynos5420_kfcclk_d), 0);
 
 	samsung_clk_extended_sleep_init(reg_base,
@@ -1651,7 +1652,6 @@ static void __init exynos5x_clk_init(struct device_node *np,
 				     exynos5x_subcmus);
 	}
 
-	hws = ctx->clk_data.hws;
 	/*
 	 * Keep top part of G3D clock path enabled permanently to ensure
 	 * that the internal busses get their clock regardless of the

drivers/clk/samsung/clk-exynos5433.c

@@ -3679,6 +3679,7 @@ static void __init exynos5433_cmu_apollo_init(struct device_node *np)
 {
 	void __iomem *reg_base;
 	struct samsung_clk_provider *ctx;
+	struct clk_hw **hws;
 
 	reg_base = of_iomap(np, 0);
 	if (!reg_base) {
@@ -3701,8 +3702,10 @@ static void __init exynos5433_cmu_apollo_init(struct device_node *np)
 	samsung_clk_register_gate(ctx, apollo_gate_clks,
 				  ARRAY_SIZE(apollo_gate_clks));
 
+	hws = ctx->clk_data.hws;
+
 	exynos_register_cpu_clock(ctx, CLK_SCLK_APOLLO, "apolloclk",
-		mout_apollo_p[0], mout_apollo_p[1], 0x200,
+		hws[CLK_MOUT_APOLLO_PLL], hws[CLK_MOUT_BUS_PLL_APOLLO_USER], 0x200,
 		exynos5433_apolloclk_d, ARRAY_SIZE(exynos5433_apolloclk_d),
 		CLK_CPU_HAS_E5433_REGS_LAYOUT);
 
@@ -3933,6 +3936,7 @@ static void __init exynos5433_cmu_atlas_init(struct device_node *np)
 {
 	void __iomem *reg_base;
 	struct samsung_clk_provider *ctx;
+	struct clk_hw **hws;
 
 	reg_base = of_iomap(np, 0);
 	if (!reg_base) {
@@ -3955,8 +3959,10 @@ static void __init exynos5433_cmu_atlas_init(struct device_node *np)
 	samsung_clk_register_gate(ctx, atlas_gate_clks,
 				  ARRAY_SIZE(atlas_gate_clks));
 
+	hws = ctx->clk_data.hws;
+
 	exynos_register_cpu_clock(ctx, CLK_SCLK_ATLAS, "atlasclk",
-		mout_atlas_p[0], mout_atlas_p[1], 0x200,
+		hws[CLK_MOUT_ATLAS_PLL], hws[CLK_MOUT_BUS_PLL_ATLAS_USER], 0x200,
 		exynos5433_atlasclk_d, ARRAY_SIZE(exynos5433_atlasclk_d),
 		CLK_CPU_HAS_E5433_REGS_LAYOUT);