MIPS: ath79: make specifying the reference clock in DT optional

It can be autodetected for many SoCs using the strapping options.
If the clock is specified in DT, the autodetected value is ignored
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org

arch/mips/ath79/clock.c

@@ -80,6 +80,18 @@ static struct clk * __init ath79_set_ff_clk(int type, const char *parent,
 	return clk;
 }
 
+static unsigned long __init ath79_setup_ref_clk(unsigned long rate)
+{
+	struct clk *clk = clks[ATH79_CLK_REF];
+
+	if (clk)
+		rate = clk_get_rate(clk);
+	else
+		clk = ath79_set_clk(ATH79_CLK_REF, rate);
+
+	return rate;
+}
+
 static void __init ar71xx_clocks_init(void __iomem *pll_base)
 {
 	unsigned long ref_rate;
@@ -90,7 +102,7 @@ static void __init ar71xx_clocks_init(void __iomem *pll_base)
 	u32 freq;
 	u32 div;
 
-	ref_rate = AR71XX_BASE_FREQ;
+	ref_rate = ath79_setup_ref_clk(AR71XX_BASE_FREQ);
 
 	pll = __raw_readl(pll_base + AR71XX_PLL_REG_CPU_CONFIG);
 
@@ -106,16 +118,17 @@ static void __init ar71xx_clocks_init(void __iomem *pll_base)
 	div = (((pll >> AR71XX_AHB_DIV_SHIFT) & AR71XX_AHB_DIV_MASK) + 1) * 2;
 	ahb_rate = cpu_rate / div;
 
-	ath79_set_clk(ATH79_CLK_REF, ref_rate);
 	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
 	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
 	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
 }
 
-static void __init ar724x_clk_init(struct clk *ref_clk, void __iomem *pll_base)
+static void __init ar724x_clocks_init(void __iomem *pll_base)
 {
-	u32 pll;
 	u32 mult, div, ddr_div, ahb_div;
+	u32 pll;
+
+	ath79_setup_ref_clk(AR71XX_BASE_FREQ);
 
 	pll = __raw_readl(pll_base + AR724X_PLL_REG_CPU_CONFIG);
 
@@ -130,17 +143,9 @@ static void __init ar724x_clk_init(struct clk *ref_clk, void __iomem *pll_base)
 	ath79_set_ff_clk(ATH79_CLK_AHB, "ref", mult, div * ahb_div);
 }
 
-static void __init ar724x_clocks_init(void __iomem *pll_base)
-{
-	struct clk *ref_clk;
-
-	ref_clk = ath79_set_clk(ATH79_CLK_REF, AR724X_BASE_FREQ);
-
-	ar724x_clk_init(ref_clk, pll_base);
-}
-
-static void __init ar9330_clk_init(struct clk *ref_clk, void __iomem *pll_base)
+static void __init ar933x_clocks_init(void __iomem *pll_base)
 {
+	unsigned long ref_rate;
 	u32 clock_ctrl;
 	u32 ref_div;
 	u32 ninit_mul;
@@ -149,6 +154,15 @@ static void __init ar9330_clk_init(struct clk *ref_clk, void __iomem *pll_base)
 	u32 cpu_div;
 	u32 ddr_div;
 	u32 ahb_div;
+	u32 t;
+
+	t = ath79_reset_rr(AR933X_RESET_REG_BOOTSTRAP);
+	if (t & AR933X_BOOTSTRAP_REF_CLK_40)
+		ref_rate = (40 * 1000 * 1000);
+	else
+		ref_rate = (25 * 1000 * 1000);
+
+	ath79_setup_ref_clk(ref_rate);
 
 	clock_ctrl = __raw_readl(pll_base + AR933X_PLL_CLOCK_CTRL_REG);
 	if (clock_ctrl & AR933X_PLL_CLOCK_CTRL_BYPASS) {
@@ -197,23 +211,6 @@ static void __init ar9330_clk_init(struct clk *ref_clk, void __iomem *pll_base)
 			 ref_div * out_div * ahb_div);
 }
 
-static void __init ar933x_clocks_init(void __iomem *pll_base)
-{
-	struct clk *ref_clk;
-	unsigned long ref_rate;
-	u32 t;
-
-	t = ath79_reset_rr(AR933X_RESET_REG_BOOTSTRAP);
-	if (t & AR933X_BOOTSTRAP_REF_CLK_40)
-		ref_rate = (40 * 1000 * 1000);
-	else
-		ref_rate = (25 * 1000 * 1000);
-
-	ref_clk = ath79_set_clk(ATH79_CLK_REF, ref_rate);
-
-	ar9330_clk_init(ref_clk, ath79_pll_base);
-}
-
 static u32 __init ar934x_get_pll_freq(u32 ref, u32 ref_div, u32 nint, u32 nfrac,
 				      u32 frac, u32 out_div)
 {
@@ -253,6 +250,8 @@ static void __init ar934x_clocks_init(void __iomem *pll_base)
 	else
 		ref_rate = 25 * 1000 * 1000;
 
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
 	pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL2_REG);
 	if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
 		out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
@@ -339,7 +338,6 @@ static void __init ar934x_clocks_init(void __iomem *pll_base)
 	else
 		ahb_rate = cpu_pll / (postdiv + 1);
 
-	ath79_set_clk(ATH79_CLK_REF, ref_rate);
 	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
 	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
 	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
@@ -363,6 +361,8 @@ static void __init qca953x_clocks_init(void __iomem *pll_base)
 	else
 		ref_rate = 25 * 1000 * 1000;
 
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
 	pll = __raw_readl(pll_base + QCA953X_PLL_CPU_CONFIG_REG);
 	out_div = (pll >> QCA953X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
 		  QCA953X_PLL_CPU_CONFIG_OUTDIV_MASK;
@@ -423,7 +423,6 @@ static void __init qca953x_clocks_init(void __iomem *pll_base)
 	else
 		ahb_rate = cpu_pll / (postdiv + 1);
 
-	ath79_set_clk(ATH79_CLK_REF, ref_rate);
 	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
 	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
 	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
@@ -445,6 +444,8 @@ static void __init qca955x_clocks_init(void __iomem *pll_base)
 	else
 		ref_rate = 25 * 1000 * 1000;
 
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
 	pll = __raw_readl(pll_base + QCA955X_PLL_CPU_CONFIG_REG);
 	out_div = (pll >> QCA955X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
 		  QCA955X_PLL_CPU_CONFIG_OUTDIV_MASK;
@@ -505,7 +506,6 @@ static void __init qca955x_clocks_init(void __iomem *pll_base)
 	else
 		ahb_rate = cpu_pll / (postdiv + 1);
 
-	ath79_set_clk(ATH79_CLK_REF, ref_rate);
 	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
 	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
 	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
@@ -537,6 +537,8 @@ static void __init qca956x_clocks_init(void __iomem *pll_base)
 	else
 		ref_rate = 25 * 1000 * 1000;
 
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
 	pll = __raw_readl(pll_base + QCA956X_PLL_CPU_CONFIG_REG);
 	out_div = (pll >> QCA956X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
 		  QCA956X_PLL_CPU_CONFIG_OUTDIV_MASK;
@@ -606,7 +608,6 @@ static void __init qca956x_clocks_init(void __iomem *pll_base)
 	else
 		ahb_rate = cpu_pll / (postdiv + 1);
 
-	ath79_set_clk(ATH79_CLK_REF, ref_rate);
 	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
 	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
 	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
@@ -682,10 +683,8 @@ static void __init ath79_clocks_init_dt_ng(struct device_node *np)
 	void __iomem *pll_base;
 
 	ref_clk = of_clk_get(np, 0);
-	if (IS_ERR(ref_clk)) {
-		pr_err("%pOF: of_clk_get failed\n", np);
-		goto err;
-	}
+	if (!IS_ERR(ref_clk))
+		clks[ATH79_CLK_REF] = ref_clk;
 
 	pll_base = of_iomap(np, 0);
 	if (!pll_base) {
@@ -694,9 +693,9 @@ static void __init ath79_clocks_init_dt_ng(struct device_node *np)
 	}
 
 	if (of_device_is_compatible(np, "qca,ar9130-pll"))
-		ar724x_clk_init(ref_clk, pll_base);
+		ar724x_clocks_init(pll_base);
 	else if (of_device_is_compatible(np, "qca,ar9330-pll"))
-		ar9330_clk_init(ref_clk, pll_base);
+		ar933x_clocks_init(pll_base);
 	else {
 		pr_err("%pOF: could not find any appropriate clk_init()\n", np);
 		goto err_iounmap;
@@ -714,9 +713,6 @@ static void __init ath79_clocks_init_dt_ng(struct device_node *np)
 
 err_clk:
 	clk_put(ref_clk);
-
-err:
-	return;
 }
 CLK_OF_DECLARE(ar9130_clk, "qca,ar9130-pll", ath79_clocks_init_dt_ng);
 CLK_OF_DECLARE(ar9330_clk, "qca,ar9330-pll", ath79_clocks_init_dt_ng);