Re: [PATCH -next] xtensa: Fix build error due to missing include file

[Max Filippov]

On Sun, Jul 24, 2016 at 7:27 PM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> On 07/24/2016 08:18 AM, Rob Herring wrote:
>>
>> On Sun, Jul 24, 2016 at 9:20 AM, Max Filippov <jcmvbkbc@xxxxxxxxx> wrote:
>>>
>>> On Sun, Jul 24, 2016 at 9:00 AM, Guenter Roeck <linux@xxxxxxxxxxxx>
>>> wrote:
>>>>
>>>> On 07/23/2016 05:45 PM, Max Filippov wrote:
>>>>>
>>>>>
>>>>> On Sun, Jul 24, 2016 at 3:24 AM, Guenter Roeck <linux@xxxxxxxxxxxx>
>>>>> wrote:
>>>>>>
>>>>>>
>>>>>> Commit 69d99e6c0d621f ("xtensa: Remove unnecessary
>>>>>> of_platform_populate
>>>>>> with default match table") dropped various include files from
>>>>>> arch/xtensa/kernel/setup.c. This results in the following build error.
>>>>>>
>>>>>> arch/xtensa/kernel/setup.c: In function âxtensa_dt_io_areaâ:
>>>>>> arch/xtensa/kernel/setup.c:213:2: error:
>>>>>>           implicit declaration of function âof_read_ulongâ
>>>>>>
>>>>>> Fixes: 69d99e6c0d621f ("xtensa: Remove unnecessary
>>>>>> of_platform_populate
>>>>>> with default match table")
>>>>>> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
>>>>>> Cc: Rob Herring <robh@xxxxxxxxxx>
>>>>>> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>>>>>> ---
>>>>>> I would suggest to merge this patch into the commit causing the
>>>>>> problem
>>>>>> if possible.
>>>>>>
>>>>>>    arch/xtensa/kernel/setup.c | 1 +
>>>>>>    1 file changed, 1 insertion(+)
>>>>>
>>>>>
>>>>>
>>>>> Acked-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
>>>>>
>>>>
>>>> Heads up: xtensa images build after this patch, but the image that
>>>> previously failed to build (generic_kc705_defconfig) doesn't boot,
>>>> at least not with qemu. I don't know if this is caused by 69d99e6c0d621f
>>>> or by some other patch.
>>>
>>>
>>> It seems to be booting, but serial console is non-functional.
>>> With commit 69d99e6c0d621f ("xtensa: Remove unnecessary
>>> of_platform_populate
>>> with default match table") I see the following message during boot:
>>>
>>> [    6.375284] of_serial fd050020.serial: clk or clock-frequency not
>>> defined
>>>
>>> Reverting that commit fixes serial console for me.
>>> Any suggestions on what might go wrong?
>>
>>
>> Probably the init order changed somehow and deferred probe is not
>> supported correctly.
>>
>
> While the message is due to -EPROBE_DEFER (and there should really be no
> message
> in this case), I suspect that the underlying problem is that of_clk_init()
> is
> now called way too early, before the clock source is fully initialized.
> Specifically, the call now happens before the message "clocksource: Switched
> to clocksource ccount", which at least looks suspicious.
>
> If I move of_clk_init() back into xtensa_device_probe(), to be called as
> device_initcall(), everything is fine.

The problem is in the way the main clock on xtfpga platform is set up:
it is done by updating corresponding OF node's clock-frequency attribute
and that must happen before the of_clk_init call.
Looks like it's time to create a clock provider for xtfpga boards, something
like the one attached.

-- 
Thanks.
-- Max
From 8aa959869060cb5ffbc06c4c25cfb0e6d81bc8b4 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@xxxxxxxxx>
Date: Mon, 25 Jul 2016 10:58:10 +0300
Subject: [PATCH] xtensa: xtfpga: add clock provider

Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
---
 arch/xtensa/boot/dts/xtfpga.dtsi     | 11 ++++++-----
 arch/xtensa/platforms/xtfpga/setup.c | 32 ++++++++++++++++++++++++++++----
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/arch/xtensa/boot/dts/xtfpga.dtsi b/arch/xtensa/boot/dts/xtfpga.dtsi
index cd45f9c..b49b5d4 100644
--- a/arch/xtensa/boot/dts/xtfpga.dtsi
+++ b/arch/xtensa/boot/dts/xtfpga.dtsi
@@ -36,11 +36,6 @@
 	};
 
 	clocks {
-		osc: main-oscillator {
-			#clock-cells = <0>;
-			compatible = "fixed-clock";
-		};
-
 		clk54: clk54 {
 			#clock-cells = <0>;
 			compatible = "fixed-clock";
@@ -54,6 +49,12 @@
 		compatible = "simple-bus";
 		ranges = <0x00000000 0xf0000000 0x10000000>;
 
+		osc: main-oscillator {
+			reg = <0x0d020004 0x4>;
+			#clock-cells = <0>;
+			compatible = "cdns,xtfpga-clock";
+		};
+
 		serial0: serial@0d050020 {
 			device_type = "serial";
 			compatible = "ns16550a";
diff --git a/arch/xtensa/platforms/xtfpga/setup.c b/arch/xtensa/platforms/xtfpga/setup.c
index b509d1f..24f22e8 100644
--- a/arch/xtensa/platforms/xtfpga/setup.c
+++ b/arch/xtensa/platforms/xtfpga/setup.c
@@ -26,6 +26,8 @@
 #include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/of.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
 
 #include <asm/timex.h>
 #include <asm/processor.h>
@@ -135,14 +137,36 @@ static void __init update_local_mac(struct device_node *node)
 	of_update_property(node, newmac);
 }
 
+static void __init xtfpga_clk_setup(struct device_node *np)
+{
+	void __iomem *base = of_iomap(np, 0);
+	struct clk *clk;
+	u32 freq;
+
+	if (!base) {
+		pr_err("%s: invalid address\n", np->name);
+		return;
+	}
+
+	freq = __raw_readl(base);
+	clk = clk_register_fixed_rate(NULL, np->name, NULL, 0, freq);
+
+	if (IS_ERR(clk)) {
+		pr_err("%s: clk registration failed\n", np->name);
+		return;
+	}
+
+	if (of_clk_add_provider(np, of_clk_src_simple_get, clk)) {
+		pr_err("%s: clk provider registration failed\n", np->name);
+		return;
+	}
+}
+CLK_OF_DECLARE(xtfpga_clk, "cdns,xtfpga-clock", xtfpga_clk_setup);
+
 static int __init machine_setup(void)
 {
-	struct device_node *clock;
 	struct device_node *eth = NULL;
 
-	for_each_node_by_name(clock, "main-oscillator")
-		update_clock_frequency(clock);
-
 	if ((eth = of_find_compatible_node(eth, NULL, "opencores,ethoc")))
 		update_local_mac(eth);
 	return 0;
-- 
2.1.4