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ARM: i.MX5 Allow DT clock providers

PATCH Superseded Martin Fuzzey 2 participants 2 messages Apr 12, 2013

Subsystems (3)
Arm (32-bit) Arm sub-architectures Arm i.MX and Layerscape

v1 of 4 Superseded Latest is v4 →

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Martin Fuzzey

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#0 lore raw

PATCH 1/1 ARM: i.MX5 Allow DT clock providers

Currently clock providers defined in the DT are not registered on i.MX5 platforms since of_clk_init() is not called.

This is not a problem for the SOC's own clocks, which are registered in code, but prevents the DT being used to define clocks for external hardware.

Fix this by calling of_clk_init() and actually using the DT to obtain the 4 SOC fixed clocks.
These are already defined in the DT but were previously just used to manually obtain the rate.

Fall back to the old scheme for non DT platforms.

Signed-off-by Martin Fuzzey <[email protected]>
---
 arch/arm/mach-imx/clk-imx51-imx53.c |   75 +++++++++++++++++++----------------
 1 files changed, 41 insertions(+), 34 deletions(-)
arch/arm/mach-imx/clk-imx51-imx53.c +41 -34
index 3228b4e..342c8b3 100644
@@ -117,17 +117,52 @@ enum imx5_clks {
 static struct clk *clk[clk_max];
 static struct clk_onecell_data clk_data;
 
+
+static struct clk * __init mx5_obtain_fixed_clock_from_dt(const char *name)
+{
+#ifdef CONFIG_OF
+	char compatible[20];
+	struct of_phandle_args phandle = {0};
+	struct clk *clk = NULL;
+
+	scnprintf(compatible, sizeof(compatible), "fsl,imx-%s", name);
+	phandle.np = of_find_compatible_node(NULL, NULL, compatible);
+	if (phandle.np) {
+		clk = of_clk_get_from_provider(&phandle);
+		of_node_put(phandle.np);
+	}
+	return clk;
+#else
+	return NULL;
+#endif
+}
+
+static struct clk * __init mx5_obtain_fixed_clock(
+			const char *name, unsigned long rate)
+{
+	struct clk *clk;
+
+	clk = mx5_obtain_fixed_clock_from_dt(name);
+	if (IS_ERR_OR_NULL(clk))
+		clk = imx_clk_fixed(name, rate);
+	return clk;
+}
+
 static void __init mx5_clocks_common_init(unsigned long rate_ckil,
 		unsigned long rate_osc, unsigned long rate_ckih1,
 		unsigned long rate_ckih2)
 {
 	int i;
 
+#ifdef CONFIG_OF
+	of_clk_init(NULL);
+#endif
+
 	clk[dummy] = imx_clk_fixed("dummy", 0);
-	clk[ckil] = imx_clk_fixed("ckil", rate_ckil);
-	clk[osc] = imx_clk_fixed("osc", rate_osc);
-	clk[ckih1] = imx_clk_fixed("ckih1", rate_ckih1);
-	clk[ckih2] = imx_clk_fixed("ckih2", rate_ckih2);
+	clk[ckil] = mx5_obtain_fixed_clock("ckil", rate_ckil);
+	clk[osc] = mx5_obtain_fixed_clock("osc", rate_osc);
+	clk[ckih1] = mx5_obtain_fixed_clock("ckih1", rate_ckih1);
+	clk[ckih2] = mx5_obtain_fixed_clock("ckih2", rate_ckih2);
 
 	clk[lp_apm] = imx_clk_mux("lp_apm", MXC_CCM_CCSR, 9, 1,
 				lp_apm_sel, ARRAY_SIZE(lp_apm_sel));

@@ -540,41 +575,13 @@ int __init mx53_clocks_init(unsigned long rate_ckil, unsigned long rate_osc,
 }
 
 #ifdef CONFIG_OF
-static void __init clk_get_freq_dt(unsigned long *ckil, unsigned long *osc,
-				   unsigned long *ckih1, unsigned long *ckih2)
-{
-	struct device_node *np;
-
-	/* retrieve the freqency of fixed clocks from device tree */
-	for_each_compatible_node(np, NULL, "fixed-clock") {
-		u32 rate;
-		if (of_property_read_u32(np, "clock-frequency", &rate))
-			continue;
-
-		if (of_device_is_compatible(np, "fsl,imx-ckil"))
-			*ckil = rate;
-		else if (of_device_is_compatible(np, "fsl,imx-osc"))
-			*osc = rate;
-		else if (of_device_is_compatible(np, "fsl,imx-ckih1"))
-			*ckih1 = rate;
-		else if (of_device_is_compatible(np, "fsl,imx-ckih2"))
-			*ckih2 = rate;
-	}
-}
-
 int __init mx51_clocks_init_dt(void)
 {
-	unsigned long ckil, osc, ckih1, ckih2;
-
-	clk_get_freq_dt(&ckil, &osc, &ckih1, &ckih2);
-	return mx51_clocks_init(ckil, osc, ckih1, ckih2);
+	return mx51_clocks_init(0, 0, 0, 0);
 }
 
 int __init mx53_clocks_init_dt(void)
 {
-	unsigned long ckil, osc, ckih1, ckih2;
-
-	clk_get_freq_dt(&ckil, &osc, &ckih1, &ckih2);
-	return mx53_clocks_init(ckil, osc, ckih1, ckih2);
+	return mx53_clocks_init(0, 0, 0, 0);
 }
 #endif
maintainer
#1 lore raw

PATCH 1/1 ARM: i.MX5 Allow DT clock providers

Quoted 26 lines · Martin Fuzzey

Currently clock providers defined in the DT are not registered on i.MX5 platforms since of_clk_init() is not called.

This is not a problem for the SOC's own clocks, which are registered in code, but prevents the DT being used to define clocks for external hardware.

Fix this by calling of_clk_init() and actually using the DT to obtain the 4 SOC fixed clocks.
These are already defined in the DT but were previously just used to manually obtain the rate.

Fall back to the old scheme for non DT platforms.

Signed-off-by Martin Fuzzey <[email protected]>
---
 arch/arm/mach-imx/clk-imx51-imx53.c |   75 +++++++++++++++++++----------------
 1 files changed, 41 insertions(+), 34 deletions(-)
arch/arm/mach-imx/clk-imx51-imx53.c +0 -0
index 3228b4e..342c8b3 100644
@@ -117,17 +117,52 @@ enum imx5_clks {
 static struct clk *clk[clk_max];
 static struct clk_onecell_data clk_data;

arch/arm/mach-imx/clk-imx51-imx53.c enum imx5_clks { · line 128

Quoted 10 lines
arch/arm/mach-imx/clk-imx51-imx53.c +9 -0
 
+
+static struct clk * __init mx5_obtain_fixed_clock_from_dt(const char *name)
+{
+#ifdef CONFIG_OF
+	char compatible[20];
+	struct of_phandle_args phandle = {0};
+	struct clk *clk = NULL;
+
+	scnprintf(compatible, sizeof(compatible), "fsl,imx-%s", name);

Can we use kasprintf here? Not that it makes a big difference currently, but it always looks a bit awkward to depend on a maximum string length.

Quoted 8 lines
arch/arm/mach-imx/clk-imx51-imx53.c +8 -0
+	phandle.np = of_find_compatible_node(NULL, NULL, compatible);
+	if (phandle.np) {
+		clk = of_clk_get_from_provider(&phandle);
+		of_node_put(phandle.np);
+	}
+	return clk;
+#else
+	return NULL;

arch/arm/mach-imx/clk-imx51-imx53.c enum imx5_clks { · line 146

Quoted 10 lines
arch/arm/mach-imx/clk-imx51-imx53.c +10 -0
+#endif
+}
+
+static struct clk * __init mx5_obtain_fixed_clock(
+			const char *name, unsigned long rate)
+{
+	struct clk *clk;
+
+	clk = mx5_obtain_fixed_clock_from_dt(name);
+	if (IS_ERR_OR_NULL(clk))

You shouldn't use IS_ERR_OR_NULL. Instead you could return ERR_PTR(-ENODEV) for !CONFIG_OF. Another option would be to inline the code from mx5_obtain_fixed_clock_from_dt here.

arch/arm/mach-imx/clk-imx51-imx53.c enum imx5_clks { · line 150

Quoted 4 lines
arch/arm/mach-imx/clk-imx51-imx53.c +4 -0
+		clk = imx_clk_fixed(name, rate);
+	return clk;
+}
+

Sascha

Signature · 4 lines
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