[PATCH v3 0/6] add device tree support for mxc rtc

[PATCH v3 0/6] add device tree support for mxc rtc

[Philippe Reynes]

This serie add the device tree support for the mxc rtc driver.
To do this, three steps are required :
- define two rtc clocks for imx31 and imx35
- enhance mxc rtc driver to use two clocks (rtc and ipg)
- add device tree support to mxc rtc driver

Changelog:
v3: (thanks Fabio Estevam)
- fix typo in imx35 clock comment
v2: (thanks Shawn Guo and Alexandre Belloni)
- add a second clock to imx35
- split the add of clock in a separate patches
- split the dt documentation in a separate patch

Philippe Reynes (6):
  imx31: add a second rtc clock
  imx35: define two clocks for rtc
  rtc: mxc: use a second rtc clock
  rtc: mxc: add support of device tree
  dt-binding: document the binding for mxc rtc
  apf27: dt: add support of internal rtc

 Documentation/devicetree/bindings/rtc/rtc-mxc.txt |   27 ++++++++++++
 arch/arm/boot/dts/imx27-apf27.dts                 |    4 ++
 arch/arm/boot/dts/imx27.dtsi                      |   10 +++++
 arch/arm/mach-imx/clk-imx31.c                     |    3 +-
 arch/arm/mach-imx/clk-imx35.c                     |    6 ++-
 drivers/rtc/rtc-mxc.c                             |   45 ++++++++++++++++-----
 6 files changed, 83 insertions(+), 12 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/rtc/rtc-mxc.txt

-- 
1.7.4.4

[PATCH v3 1/6] imx31: add a second rtc clock

[Philippe Reynes]

The mxc rtc driver needs two clock.
It was defined only one clock, so we
define the second clock.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
---
 arch/arm/mach-imx/clk-imx31.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-imx/clk-imx31.c b/arch/arm/mach-imx/clk-imx31.c
index 286ef42..480c54f 100644
--- a/arch/arm/mach-imx/clk-imx31.c
+++ b/arch/arm/mach-imx/clk-imx31.c
@@ -130,7 +130,8 @@ int __init mx31_clocks_init(unsigned long fref)
 	clk_register_clkdev(clk[cspi3_gate], NULL, "imx31-cspi.2");
 	clk_register_clkdev(clk[pwm_gate], "pwm", NULL);
 	clk_register_clkdev(clk[wdog_gate], NULL, "imx2-wdt.0");
-	clk_register_clkdev(clk[rtc_gate], NULL, "imx21-rtc");
+	clk_register_clkdev(clk[ckil], "rtc", "imx21-rtc");
+	clk_register_clkdev(clk[rtc_gate], "ipg", "imx21-rtc");
 	clk_register_clkdev(clk[epit1_gate], "epit", NULL);
 	clk_register_clkdev(clk[epit2_gate], "epit", NULL);
 	clk_register_clkdev(clk[nfc], NULL, "imx27-nand.0");
-- 
1.7.4.4

[PATCH v3 2/6] imx35: define two clocks for rtc

[Philippe Reynes]

The imx35 don't define clocks for rtc.
This patch add two clocks, as needed
by the mxc rtc driver.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
---
 arch/arm/mach-imx/clk-imx35.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-imx/clk-imx35.c b/arch/arm/mach-imx/clk-imx35.c
index a0d2b57..8c84eee 100644
--- a/arch/arm/mach-imx/clk-imx35.c
+++ b/arch/arm/mach-imx/clk-imx35.c
@@ -51,7 +51,7 @@ static const char *std_sel[] = {"ppll", "arm"};
 static const char *ipg_per_sel[] = {"ahb_per_div", "arm_per_div"};
 
 enum mx35_clks {
-	ckih, mpll, ppll, mpll_075, arm, hsp, hsp_div, hsp_sel, ahb, ipg,
+	ckih, ckil, mpll, ppll, mpll_075, arm, hsp, hsp_div, hsp_sel, ahb, ipg,
 	arm_per_div, ahb_per_div, ipg_per, uart_sel, uart_div, esdhc_sel,
 	esdhc1_div, esdhc2_div, esdhc3_div, spdif_sel, spdif_div_pre,
 	spdif_div_post, ssi_sel, ssi1_div_pre, ssi1_div_post, ssi2_div_pre,
@@ -89,6 +89,7 @@ int __init mx35_clocks_init(void)
 	}
 
 	clk[ckih] = imx_clk_fixed("ckih", 24000000);
+	clk[ckil] = imx_clk_fixed("ckih", 32768);
 	clk[mpll] = imx_clk_pllv1("mpll", "ckih", base + MX35_CCM_MPCTL);
 	clk[ppll] = imx_clk_pllv1("ppll", "ckih", base + MX35_CCM_PPCTL);
 
@@ -240,6 +241,9 @@ int __init mx35_clocks_init(void)
 	clk_register_clkdev(clk[ipg], "ipg", "imx21-uart.1");
 	clk_register_clkdev(clk[uart3_gate], "per", "imx21-uart.2");
 	clk_register_clkdev(clk[ipg], "ipg", "imx21-uart.2");
+	/* i.mx35 has the i.mx21 type rtc */
+	clk_register_clkdev(clk[ckil], "rtc", "imx21-rtc");
+	clk_register_clkdev(clk[rtc_gate], "ipg", "imx21-rtc");
 	clk_register_clkdev(clk[usb_div], "per", "mxc-ehci.0");
 	clk_register_clkdev(clk[ipg], "ipg", "mxc-ehci.0");
 	clk_register_clkdev(clk[usbotg_gate], "ahb", "mxc-ehci.0");
-- 
1.7.4.4

[PATCH v3 3/6] rtc: mxc: use a second rtc clock

[Philippe Reynes]

The mxc RTC needs two clocks, one for the input
reference, and one for the IP. But this driver
was only using one clock (for the reference).
This patch add the second clock (for the IP).

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
---
 drivers/rtc/rtc-mxc.c |   26 +++++++++++++++++---------
 1 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index 09d422b..e916a91 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -79,7 +79,8 @@ struct rtc_plat_data {
 	struct rtc_device *rtc;
 	void __iomem *ioaddr;
 	int irq;
-	struct clk *clk;
+	struct clk *clk_rtc;
+	struct clk *clk_ipg;
 	struct rtc_time g_rtc_alarm;
 	enum imx_rtc_type devtype;
 };
@@ -373,17 +374,24 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 	if (IS_ERR(pdata->ioaddr))
 		return PTR_ERR(pdata->ioaddr);
 
-	pdata->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(pdata->clk)) {
-		dev_err(&pdev->dev, "unable to get clock!\n");
-		return PTR_ERR(pdata->clk);
+	pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(pdata->clk_ipg)) {
+		dev_err(&pdev->dev, "unable to get ipg clock!\n");
+		return PTR_ERR(pdata->clk_ipg);
 	}
 
-	ret = clk_prepare_enable(pdata->clk);
+	ret = clk_prepare_enable(pdata->clk_ipg);
 	if (ret)
 		return ret;
 
-	rate = clk_get_rate(pdata->clk);
+	pdata->clk_rtc = devm_clk_get(&pdev->dev, "rtc");
+	if (IS_ERR(pdata->clk_rtc)) {
+		dev_err(&pdev->dev, "unable to get rtc clock!\n");
+		ret = PTR_ERR(pdata->clk_rtc);
+		goto exit_put_clk;
+	}
+
+	rate = clk_get_rate(pdata->clk_rtc);
 
 	if (rate == 32768)
 		reg = RTC_INPUT_CLK_32768HZ;
@@ -432,7 +440,7 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 	return 0;
 
 exit_put_clk:
-	clk_disable_unprepare(pdata->clk);
+	clk_disable_unprepare(pdata->clk_ipg);
 
 	return ret;
 }
@@ -441,7 +449,7 @@ static int mxc_rtc_remove(struct platform_device *pdev)
 {
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	clk_disable_unprepare(pdata->clk);
+	clk_disable_unprepare(pdata->clk_ipg);
 
 	return 0;
 }
-- 
1.7.4.4

[PATCH v3 3/6] rtc: mxc: use a second rtc clock

[Alexandre Belloni]

Hi,

On 20/06/2015 at 19:12:37 +0200, Philippe Reynes wrote :
> -	rate = clk_get_rate(pdata->clk);
> +	pdata->clk_rtc = devm_clk_get(&pdev->dev, "rtc");
> +	if (IS_ERR(pdata->clk_rtc)) {
> +		dev_err(&pdev->dev, "unable to get rtc clock!\n");
> +		ret = PTR_ERR(pdata->clk_rtc);
> +		goto exit_put_clk;
> +	}
> +
> +	rate = clk_get_rate(pdata->clk_rtc);
>  

You have to prepare_enable() before using get_rate(). Else, it is not
guaranteed to work:
"clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
                This is only valid once the clock source has been enabled."
http://lxr.free-electrons.com/source/include/linux/clk.h#L269

It may work right now because the clock is enabled elsewhere. But that
may change at some point in time (we had the issue on at91).


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH v3 4/6] rtc: mxc: add support of device tree

[Philippe Reynes]

Add device tree support for the mxc rtc driver.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
---
 drivers/rtc/rtc-mxc.c |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index e916a91..befe2c2 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -16,6 +16,8 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #define RTC_INPUT_CLK_32768HZ	(0x00 << 5)
 #define RTC_INPUT_CLK_32000HZ	(0x01 << 5)
@@ -98,6 +100,15 @@ static struct platform_device_id imx_rtc_devtype[] = {
 };
 MODULE_DEVICE_TABLE(platform, imx_rtc_devtype);
 
+#ifdef CONFIG_OF
+static const struct of_device_id imx_rtc_dt_ids[] = {
+	{ .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC },
+	{ .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC },
+	{}
+};
+MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids);
+#endif
+
 static inline int is_imx1_rtc(struct rtc_plat_data *data)
 {
 	return data->devtype == IMX1_RTC;
@@ -362,12 +373,17 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 	u32 reg;
 	unsigned long rate;
 	int ret;
+	const struct of_device_id *of_id;
 
 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
 
-	pdata->devtype = pdev->id_entry->driver_data;
+	of_id = of_match_device(imx_rtc_dt_ids, &pdev->dev);
+	if (of_id)
+		pdata->devtype = (enum imx_rtc_type)of_id->data;
+	else
+		pdata->devtype = pdev->id_entry->driver_data;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
@@ -481,6 +497,7 @@ static SIMPLE_DEV_PM_OPS(mxc_rtc_pm_ops, mxc_rtc_suspend, mxc_rtc_resume);
 static struct platform_driver mxc_rtc_driver = {
 	.driver = {
 		   .name	= "mxc_rtc",
+		   .of_match_table = of_match_ptr(imx_rtc_dt_ids),
 		   .pm		= &mxc_rtc_pm_ops,
 	},
 	.id_table = imx_rtc_devtype,
-- 
1.7.4.4

[PATCH v3 4/6] rtc: mxc: add support of device tree

[Alexandre Belloni]

On 20/06/2015 at 19:12:38 +0200, Philippe Reynes wrote :
> Add device tree support for the mxc rtc driver.
> 
> Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH v3 5/6] dt-binding: document the binding for mxc rtc

[Philippe Reynes]

This adds documentation of device tree bindings for the
mxc rtc.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: devicetree at vger.kernel.org
Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
---
 Documentation/devicetree/bindings/rtc/rtc-mxc.txt |   27 +++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/rtc/rtc-mxc.txt

diff --git a/Documentation/devicetree/bindings/rtc/rtc-mxc.txt b/Documentation/devicetree/bindings/rtc/rtc-mxc.txt
new file mode 100644
index 0000000..5505493
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-mxc.txt
@@ -0,0 +1,27 @@
+* Real Time Clock of the i.MX SoCs
+
+RTC controller for the i.MX SoCs
+
+Required properties:
+- compatible: Should be "fsl,imx1-rtc" or "fsl,imx21-rtc".
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- interrupts: IRQ line for the RTC.
+- clocks: should contain two entries:
+  * one for the input reference
+  * one for the the SoC RTC
+- clock-names: should contain:
+  * "rtc" for the input reference clock
+  * "ipg" for the SoC RTC clock
+
+Example:
+
+rtc at 10007000 {
+	compatible = "fsl,imx21-rtc";
+	reg = <0x10007000 0x1000>;
+	interrupts = <22>;
+	clocks = <&clks IMX27_CLK_CKIL>,
+	       	 <&clks IMX27_CLK_RTC_IPG_GATE>;
+	clock-names = "rtc, "ipg";
+	status = "disabled";
+};
-- 
1.7.4.4

[PATCH v3 5/6] dt-binding: document the binding for mxc rtc

[Rob Herring]

On Sat, Jun 20, 2015 at 12:12 PM, Philippe Reynes <tremyfr@gmail.com> wrote:
> This adds documentation of device tree bindings for the
> mxc rtc.

Perhaps don't further propagate the long dead MXC name and use "imx"
everywhere. What the Linux driver is called doesn't matter here.

> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Pawel Moll <pawel.moll@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
> Cc: Kumar Gala <galak@codeaurora.org>
> Cc: devicetree at vger.kernel.org
> Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
> ---
>  Documentation/devicetree/bindings/rtc/rtc-mxc.txt |   27 +++++++++++++++++++++
>  1 files changed, 27 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/rtc/rtc-mxc.txt
>
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-mxc.txt b/Documentation/devicetree/bindings/rtc/rtc-mxc.txt
> new file mode 100644
> index 0000000..5505493
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/rtc-mxc.txt
> @@ -0,0 +1,27 @@
> +* Real Time Clock of the i.MX SoCs
> +
> +RTC controller for the i.MX SoCs
> +
> +Required properties:
> +- compatible: Should be "fsl,imx1-rtc" or "fsl,imx21-rtc".

What about newer versions with the secure functionality. IIRC, that
was in MX31 and later.

> +- reg: physical base address of the controller and length of memory mapped
> +  region.
> +- interrupts: IRQ line for the RTC.
> +- clocks: should contain two entries:
> +  * one for the input reference
> +  * one for the the SoC RTC
> +- clock-names: should contain:
> +  * "rtc" for the input reference clock
> +  * "ipg" for the SoC RTC clock
> +
> +Example:
> +
> +rtc at 10007000 {
> +       compatible = "fsl,imx21-rtc";
> +       reg = <0x10007000 0x1000>;
> +       interrupts = <22>;
> +       clocks = <&clks IMX27_CLK_CKIL>,
> +                <&clks IMX27_CLK_RTC_IPG_GATE>;
> +       clock-names = "rtc, "ipg";
> +       status = "disabled";
> +};
> --
> 1.7.4.4
>

[PATCH v3 5/6] dt-binding: document the binding for mxc rtc

[Alexandre Belloni]

On 22/06/2015 at 08:59:06 -0500, Rob Herring wrote :
> What about newer versions with the secure functionality. IIRC, that
> was in MX31 and later.
> 

Aren't those covered by the snvs driver?


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH v3 6/6] apf27: dt: add support of internal rtc

[Philippe Reynes]

Enable the internal mxc rtc driver on apf27.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
---
 arch/arm/boot/dts/imx27-apf27.dts |    4 ++++
 arch/arm/boot/dts/imx27.dtsi      |   10 ++++++++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/arch/arm/boot/dts/imx27-apf27.dts b/arch/arm/boot/dts/imx27-apf27.dts
index 73aae4f..590d37a 100644
--- a/arch/arm/boot/dts/imx27-apf27.dts
+++ b/arch/arm/boot/dts/imx27-apf27.dts
@@ -122,3 +122,7 @@
 		reg = <0x800000 0xf800000>;
 	};
 };
+
+&rtc {
+	status = "okay";
+};
diff --git a/arch/arm/boot/dts/imx27.dtsi b/arch/arm/boot/dts/imx27.dtsi
index bc215e4..57fda6c 100644
--- a/arch/arm/boot/dts/imx27.dtsi
+++ b/arch/arm/boot/dts/imx27.dtsi
@@ -144,6 +144,16 @@
 				clock-names = "ipg", "per";
 			};
 
+			rtc: rtc at 10007000 {
+				compatible = "fsl,imx21-rtc";
+				reg = <0x10007000 0x1000>;
+				interrupts = <22>;
+				clocks = <&clks IMX27_CLK_CKIL>,
+					 <&clks IMX27_CLK_RTC_IPG_GATE>;
+				clock-names = "rtc", "ipg";
+				status = "disabled";
+			};
+
 			kpp: kpp at 10008000 {
 				compatible = "fsl,imx27-kpp", "fsl,imx21-kpp";
 				reg = <0x10008000 0x1000>;
-- 
1.7.4.4

[PATCH v3 6/6] apf27: dt: add support of internal rtc

[Alexandre Belloni]

On 20/06/2015 at 19:12:40 +0200, Philippe Reynes wrote :
> Enable the internal mxc rtc driver on apf27.
> 
> Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
> ---
>  arch/arm/boot/dts/imx27-apf27.dts |    4 ++++
>  arch/arm/boot/dts/imx27.dtsi      |   10 ++++++++++
>  2 files changed, 14 insertions(+), 0 deletions(-)
> 

I'm not the one taking the patch but I usually separate the addition in
the dtsi from the use in the dts in different patches. But it is up to
Shawn to share his preference.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com