[PATCH 1/3] arm: dts: imx6qdl: add clocks property for ocotp node

[PATCH 1/3] arm: dts: imx6qdl: add clocks property for ocotp node

[Peng Fan]

Add clocks property for ocotp node.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
---
 arch/arm/boot/dts/imx6qdl.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index b42822a..6b2ef6c 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -1100,6 +1100,7 @@
 			ocotp: ocotp@021bc000 {
 				compatible = "fsl,imx6q-ocotp", "syscon";
 				reg = <0x021bc000 0x4000>;
+				clocks = <&clks IMX6QDL_CLK_IIM>;
 			};
 
 			tzasc@021d0000 { /* TZASC1 */
-- 
1.8.4.5

[PATCH 2/3] arm: dts: imx6sl: add clocks property for ocotp node

[Peng Fan]

Add clocks property for ocotp node.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
---
 arch/arm/boot/dts/imx6sl.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/imx6sl.dtsi b/arch/arm/boot/dts/imx6sl.dtsi
index d12b250..b37da94 100644
--- a/arch/arm/boot/dts/imx6sl.dtsi
+++ b/arch/arm/boot/dts/imx6sl.dtsi
@@ -853,6 +853,7 @@
 			ocotp: ocotp@021bc000 {
 				compatible = "fsl,imx6sl-ocotp", "syscon";
 				reg = <0x021bc000 0x4000>;
+				clocks = <&clks IMX6SL_CLK_OCOTP>;
 			};
 
 			audmux: audmux@021d8000 {
-- 
1.8.4.5

[PATCH 3/3] nvmem: imx-ocotp: handling clock

[Peng Fan]

Before access ocotp nvmem area, the clock should be enabled.
Or, `hexdump nvmem` will hang the system. So, use such flow:
"
  1. clock_enable_prepare
  2. read nvmem ocotp area
  3. clock_disable_unprepare
"

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Shawn Guo <shawnguo@kernel.org>
---
 drivers/nvmem/imx-ocotp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
index d7796eb..55095c0 100644
--- a/drivers/nvmem/imx-ocotp.c
+++ b/drivers/nvmem/imx-ocotp.c
@@ -15,6 +15,7 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
+#include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -27,6 +28,7 @@
 
 struct ocotp_priv {
 	struct device *dev;
+	struct clk *clk;
 	void __iomem *base;
 	unsigned int nregs;
 };
@@ -46,11 +48,15 @@ static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
 	if (count > (priv->nregs - index))
 		count = priv->nregs - index;
 
+	clk_prepare_enable(priv->clk);
+
 	for (i = index; i < (index + count); i++) {
 		*(u32 *)val = readl(priv->base + 0x400 + i * 0x10);
 		val += 4;
 	}
 
+	clk_disable_unprepare(priv->clk);
+
 	return 0;
 }
 
@@ -112,6 +118,10 @@ static int imx_ocotp_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->base))
 		return PTR_ERR(priv->base);
 
+	priv->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk))
+		return PTR_ERR(priv->clk);
+
 	of_id = of_match_device(imx_ocotp_dt_ids, dev);
 	priv->nregs = (unsigned int)of_id->data;
 	imx_ocotp_regmap_config.max_register = 4 * priv->nregs - 4;
-- 
1.8.4.5

Re: [PATCH 3/3] nvmem: imx-ocotp: handling clock

[Fabio Estevam]

Hi Peng,

On Tue, Apr 19, 2016 at 5:33 AM, Peng Fan <van.freenix-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> @@ -46,11 +48,15 @@ static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
>         if (count > (priv->nregs - index))
>                 count = priv->nregs - index;
>
> +       clk_prepare_enable(priv->clk);

clk_prepare_enable() may fail, so you should better check its return
value and propagate it in the case of error.
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Re: [PATCH 3/3] nvmem: imx-ocotp: handling clock

[Peng Fan]

Hi Fabio,
On Tue, Apr 19, 2016 at 07:42:17AM -0300, Fabio Estevam wrote:
>Hi Peng,
>
>On Tue, Apr 19, 2016 at 5:33 AM, Peng Fan <van.freenix@gmail.com> wrote:
>
>> @@ -46,11 +48,15 @@ static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
>>         if (count > (priv->nregs - index))
>>                 count = priv->nregs - index;
>>
>> +       clk_prepare_enable(priv->clk);
>
>clk_prepare_enable() may fail, so you should better check its return
>value and propagate it in the case of error.

Thanks for correcting me. Will fix it in V2.

Thanks,
Peng

--