clk: qoriq: Separate root input clock for core PLLs on ls1012a

ls1012a has separate input root clocks for core PLLs versus the
platform PLL, with the latter described as sysclk in the hw docs.
If a second input clock, named "coreclk", is present, this clock will be
used for the core PLLs.
Signed-off-by: NScott Wood <oss@buserror.net>
Signed-off-by: NTang Yuantian <andy.tang@nxp.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

drivers/clk/clk-qoriq.c

@@ -87,7 +87,7 @@ struct clockgen {
 	struct device_node *node;
 	void __iomem *regs;
 	struct clockgen_chipinfo info; /* mutable copy */
-	struct clk *sysclk;
+	struct clk *sysclk, *coreclk;
 	struct clockgen_pll pll[6];
 	struct clk *cmux[NUM_CMUX];
 	struct clk *hwaccel[NUM_HWACCEL];
@@ -904,7 +904,12 @@ static void __init create_muxes(struct clockgen *cg)
 
 static void __init clockgen_init(struct device_node *np);
 
-/* Legacy nodes may get probed before the parent clockgen node */
+/*
+ * Legacy nodes may get probed before the parent clockgen node.
+ * It is assumed that device trees with legacy nodes will not
+ * contain a "clocks" property -- otherwise the input clocks may
+ * not be initialized at this point.
+ */
 static void __init legacy_init_clockgen(struct device_node *np)
 {
 	if (!clockgen.node)
@@ -945,18 +950,13 @@ static struct clk __init
 	return clk_register_fixed_rate(NULL, name, NULL, 0, rate);
 }
 
-static struct clk *sysclk_from_parent(const char *name)
+static struct clk __init *input_clock(const char *name, struct clk *clk)
 {
-	struct clk *clk;
-	const char *parent_name;
-
-	clk = of_clk_get(clockgen.node, 0);
-	if (IS_ERR(clk))
-		return clk;
+	const char *input_name;
 
 	/* Register the input clock under the desired name. */
-	parent_name = __clk_get_name(clk);
-	clk = clk_register_fixed_factor(NULL, name, parent_name,
+	input_name = __clk_get_name(clk);
+	clk = clk_register_fixed_factor(NULL, name, input_name,
 					0, 1, 1);
 	if (IS_ERR(clk))
 		pr_err("%s: Couldn't register %s: %ld\n", __func__, name,
@@ -965,6 +965,29 @@ static struct clk *sysclk_from_parent(const char *name)
 	return clk;
 }
 
+static struct clk __init *input_clock_by_name(const char *name,
+					      const char *dtname)
+{
+	struct clk *clk;
+
+	clk = of_clk_get_by_name(clockgen.node, dtname);
+	if (IS_ERR(clk))
+		return clk;
+
+	return input_clock(name, clk);
+}
+
+static struct clk __init *input_clock_by_index(const char *name, int idx)
+{
+	struct clk *clk;
+
+	clk = of_clk_get(clockgen.node, 0);
+	if (IS_ERR(clk))
+		return clk;
+
+	return input_clock(name, clk);
+}
+
 static struct clk * __init create_sysclk(const char *name)
 {
 	struct device_node *sysclk;
@@ -974,7 +997,11 @@ static struct clk * __init create_sysclk(const char *name)
 	if (!IS_ERR(clk))
 		return clk;
 
-	clk = sysclk_from_parent(name);
+	clk = input_clock_by_name(name, "sysclk");
+	if (!IS_ERR(clk))
+		return clk;
+
+	clk = input_clock_by_index(name, 0);
 	if (!IS_ERR(clk))
 		return clk;
 
@@ -985,7 +1012,27 @@ static struct clk * __init create_sysclk(const char *name)
 			return clk;
 	}
 
-	pr_err("%s: No input clock\n", __func__);
+	pr_err("%s: No input sysclk\n", __func__);
+	return NULL;
+}
+
+static struct clk * __init create_coreclk(const char *name)
+{
+	struct clk *clk;
+
+	clk = input_clock_by_name(name, "coreclk");
+	if (!IS_ERR(clk))
+		return clk;
+
+	/*
+	 * This indicates a mix of legacy nodes with the new coreclk
+	 * mechanism, which should never happen.  If this error occurs,
+	 * don't use the wrong input clock just because coreclk isn't
+	 * ready yet.
+	 */
+	if (WARN_ON(PTR_ERR(clk) == -EPROBE_DEFER))
+		return clk;
+
 	return NULL;
 }
 
@@ -1008,11 +1055,19 @@ static void __init create_one_pll(struct clockgen *cg, int idx)
 	u32 __iomem *reg;
 	u32 mult;
 	struct clockgen_pll *pll = &cg->pll[idx];
+	const char *input = "cg-sysclk";
 	int i;
 
 	if (!(cg->info.pll_mask & (1 << idx)))
 		return;
 
+	if (cg->coreclk && idx != PLATFORM_PLL) {
+		if (IS_ERR(cg->coreclk))
+			return;
+
+		input = "cg-coreclk";
+	}
+
 	if (cg->info.flags & CG_VER3) {
 		switch (idx) {
 		case PLATFORM_PLL:
@@ -1063,7 +1118,7 @@ static void __init create_one_pll(struct clockgen *cg, int idx)
 			 "cg-pll%d-div%d", idx, i + 1);
 
 		clk = clk_register_fixed_factor(NULL,
-				pll->div[i].name, "cg-sysclk", 0, mult, i + 1);
+				pll->div[i].name, input, 0, mult, i + 1);
 		if (IS_ERR(clk)) {
 			pr_err("%s: %s: register failed %ld\n",
 			       __func__, pll->div[i].name, PTR_ERR(clk));
@@ -1200,6 +1255,13 @@ static struct clk *clockgen_clk_get(struct of_phandle_args *clkspec, void *data)
 			goto bad_args;
 		clk = pll->div[idx].clk;
 		break;
+	case 5:
+		if (idx != 0)
+			goto bad_args;
+		clk = cg->coreclk;
+		if (IS_ERR(clk))
+			clk = NULL;
+		break;
 	default:
 		goto bad_args;
 	}
@@ -1311,6 +1373,7 @@ static void __init clockgen_init(struct device_node *np)
 		clockgen.info.flags |= CG_CMUX_GE_PLAT;
 
 	clockgen.sysclk = create_sysclk("cg-sysclk");
+	clockgen.coreclk = create_coreclk("cg-coreclk");
 	create_plls(&clockgen);
 	create_muxes(&clockgen);