diff mbox

[2/3] nvmem: imx-ocotp: Add i.MX6 OCOTP driver

Message ID 1438693342-605-2-git-send-email-p.zabel@pengutronix.de (mailing list archive)
State New, archived
Headers show

Commit Message

Philipp Zabel Aug. 4, 2015, 1:02 p.m. UTC 
This driver handles the i.MX On-Chip OTP Controller found in
i.MX6Q/D, i.MX6S/DL, i.MX6SL, and i.MX6SX SoCs. Currently it
just returns the values stored in the shadow registers.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
This patch is based on the v9 "Add simple NVMEM Framework via regmap"
series which can be found here: https://lkml.org/lkml/2015/7/27/342
---
 drivers/nvmem/Kconfig     |  11 ++++
 drivers/nvmem/Makefile    |   2 +
 drivers/nvmem/imx-ocotp.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 168 insertions(+)
 create mode 100644 drivers/nvmem/imx-ocotp.c

Comments

Srinivas Kandagatla Aug. 6, 2015, 4:20 p.m. UTC | #1 
Few Nits..

On 04/08/15 14:02, Philipp Zabel wrote:
> This driver handles the i.MX On-Chip OTP Controller found in
> i.MX6Q/D, i.MX6S/DL, i.MX6SL, and i.MX6SX SoCs. Currently it
> just returns the values stored in the shadow registers.
>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> This patch is based on the v9 "Add simple NVMEM Framework via regmap"
> series which can be found here: https://lkml.org/lkml/2015/7/27/342
> ---
>   drivers/nvmem/Kconfig     |  11 ++++
>   drivers/nvmem/Makefile    |   2 +
>   drivers/nvmem/imx-ocotp.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 168 insertions(+)
>   create mode 100644 drivers/nvmem/imx-ocotp.c
>
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index 8db2978..0b33014 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -36,4 +36,15 @@ config NVMEM_SUNXI_SID
>   	  This driver can also be built as a module. If so, the module
>   	  will be called nvmem_sunxi_sid.
>
> +config NVMEM_IMX_OCOTP
> +	tristate "i.MX6 On-Chip OTP Controller support"
> +	depends on SOC_IMX6
> +	help
> +	  This is a driver for the On-Chip OTP Controller (OCOTP) available on
> +	  i.MX6 SoCs, providing access to 4 Kbits of one-time programmable
> +	  eFuses.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called nvmem-imx-ocotp.
> +
>   endif
> diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
> index 4328b93..b512d77 100644
> --- a/drivers/nvmem/Makefile
> +++ b/drivers/nvmem/Makefile
> @@ -10,3 +10,5 @@ obj-$(CONFIG_QCOM_QFPROM)	+= nvmem_qfprom.o
>   nvmem_qfprom-y			:= qfprom.o
>   obj-$(CONFIG_NVMEM_SUNXI_SID)	+= nvmem_sunxi_sid.o
>   nvmem_sunxi_sid-y		:= sunxi_sid.o
> +obj-$(CONFIG_NVMEM_IMX_OCOTP)	+= nvmem-imx-ocotp.o
> +nvmem-imx-ocotp-y		:= imx-ocotp.o
> diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
> new file mode 100644
> index 0000000..e918967
> --- /dev/null
> +++ b/drivers/nvmem/imx-ocotp.c
> @@ -0,0 +1,155 @@
> +/*
> + * i.MX6 OCOTP fusebox driver
> + *
> + * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
> + *
> + * Based on the barebox ocotp driver,
> + * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
> + *	Orex Computed Radiography
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include <linux/clk.h>
May be you can drop this?

BTW, who is taking care of the gated peripheral clock controlled for 
this driver?


> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/nvmem-provider.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +struct ocotp_priv {
> +	struct device *dev;
> +	void __iomem *base;
> +	unsigned int nregs;
> +};
> +
> +static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
> +			  void *val, size_t val_size)
> +{
> +	struct ocotp_priv *priv = context;
> +	unsigned int offset = *(u32 *)reg;
> +	unsigned int count;
> +	int i;
> +	u32 index;
> +
> +	index = offset >> 2;
> +	count = val_size >> 2;
> +
> +	if (count > (priv->nregs - index))
> +		count = priv->nregs - index;
> +
> +	for (i = index; i < (index + count); i++) {
> +		*(u32 *)val = readl(priv->base + 0x400 + i * 0x10);
> +		val += 4;
> +	}
> +
> +	return (i - index) * 4;
> +}
> +
> +static int imx_ocotp_write(void *context, const void *data, size_t count)
> +{
> +	/* Not implemented */
> +	return 0;
> +}
> +
> +static struct regmap_bus imx_ocotp_bus = {
> +	.read = imx_ocotp_read,
> +	.write = imx_ocotp_write,
> +	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
> +	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
> +};
> +
> +static bool imx_ocotp_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +	return false;
> +}
> +
> +static struct regmap_config imx_ocotp_regmap_config = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +	.writeable_reg = imx_ocotp_writeable_reg,
> +	.name = "imx-ocotp",
> +};
> +
> +static struct nvmem_config imx_ocotp_nvmem_config = {
> +	.name = "imx-ocotp",
> +	.read_only = true,
> +	.owner = THIS_MODULE,
> +};
> +
> +static const struct of_device_id imx_ocotp_dt_ids[] = {
> +	{ .compatible = "fsl,imx6q-ocotp",  (void *)128 },
> +	{ .compatible = "fsl,imx6sl-ocotp", (void *)32 },
> +	{ .compatible = "fsl,imx6sx-ocotp", (void *)128 },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
> +
> +static int imx_ocotp_probe(struct platform_device *pdev)
> +{
> +	const struct of_device_id *of_id;
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	struct regmap *regmap;
> +	struct ocotp_priv *priv;
> +	struct nvmem_device *nvmem;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	priv->base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(priv->base))
> +		return PTR_ERR(priv->base);
> +
> +	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;
> +
> +	regmap = devm_regmap_init(dev, &imx_ocotp_bus, priv,
> +				  &imx_ocotp_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(dev, "regmap init failed\n");
> +		return PTR_ERR(regmap);
> +	}
> +	imx_ocotp_nvmem_config.dev = dev;
> +	nvmem = nvmem_register(&imx_ocotp_nvmem_config);
> +	if (IS_ERR(nvmem))
> +		return PTR_ERR(nvmem);
> +
> +	platform_set_drvdata(pdev, nvmem);
> +
> +	return 0;
> +}
> +
> +static int imx_ocotp_remove(struct platform_device *pdev)
> +{
> +	struct nvmem_device *nvmem = platform_get_drvdata(pdev);
> +
> +	return nvmem_unregister(nvmem);
> +}
> +
> +static struct platform_driver imx_ocotp_driver = {
> +	.probe	= imx_ocotp_probe,
> +	.remove	= imx_ocotp_remove,
> +	.driver = {
> +		.name	= "imx_ocotp",
> +		.of_match_table = imx_ocotp_dt_ids,
> +	},
> +};
> +module_platform_driver(imx_ocotp_driver);
> +
> +MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
> +MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
> +MODULE_LICENSE("GPL");

GPL v2 ?

>
Philipp Zabel Aug. 6, 2015, 4:28 p.m. UTC | #2 
Hi Srinivas,

Am Donnerstag, den 06.08.2015, 17:20 +0100 schrieb Srinivas Kandagatla:
> Few Nits..
> 
> On 04/08/15 14:02, Philipp Zabel wrote:
> > +#include <linux/clk.h>
> May be you can drop this?

Yes, that's a left-over and can be removed.

> BTW, who is taking care of the gated peripheral clock controlled for 
> this driver?

Nobody. I had initially copied the code that actually senses the fuses,
but since this happens during power-on reset anyway (all values are
stored in shadow registers), I didn't see the point and dropped it for
now.
The shadow registers are clocked directly by the ungated ipg_root clock.

[...]
> > +MODULE_LICENSE("GPL");
> 
> GPL v2 ?

Will do.

thanks
Philipp
Srinivas Kandagatla Aug. 6, 2015, 7:36 p.m. UTC | #3 
Hi Philipp,

Could you add Greg KH in the CC, for next merge window, we can request 
Greg to take this driver via his tree.

Once the comments are fixed you can add my

Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On 06/08/15 17:28, Philipp Zabel wrote:
> Hi Srinivas,
>
> Am Donnerstag, den 06.08.2015, 17:20 +0100 schrieb Srinivas Kandagatla:
>> Few Nits..
>>
>> On 04/08/15 14:02, Philipp Zabel wrote:
>>> +#include <linux/clk.h>
>> May be you can drop this?
>
> Yes, that's a left-over and can be removed.
>
>> BTW, who is taking care of the gated peripheral clock controlled for
>> this driver?
>
> Nobody. I had initially copied the code that actually senses the fuses,
> but since this happens during power-on reset anyway (all values are
> stored in shadow registers), I didn't see the point and dropped it for
> now.
> The shadow registers are clocked directly by the ungated ipg_root clock.

So, are you planning to drop the clocks property from the bindings too?

--srini



>
> [...]
>>> +MODULE_LICENSE("GPL");
>>
>> GPL v2 ?
>
> Will do.
>
> thanks
> Philipp
>
Philipp Zabel Aug. 7, 2015, 7:46 a.m. UTC | #4 
Am Donnerstag, den 06.08.2015, 20:36 +0100 schrieb Srinivas Kandagatla:
> Hi Philipp,
> 
> Could you add Greg KH in the CC, for next merge window, we can request 
> Greg to take this driver via his tree.
> 
> Once the comments are fixed you can add my
> 
> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
> On 06/08/15 17:28, Philipp Zabel wrote:
> > Hi Srinivas,
> >
> > Am Donnerstag, den 06.08.2015, 17:20 +0100 schrieb Srinivas Kandagatla:
> >> Few Nits..
> >>
> >> On 04/08/15 14:02, Philipp Zabel wrote:
> >>> +#include <linux/clk.h>
> >> May be you can drop this?
> >
> > Yes, that's a left-over and can be removed.
> >
> >> BTW, who is taking care of the gated peripheral clock controlled for
> >> this driver?
> >
> > Nobody. I had initially copied the code that actually senses the fuses,
> > but since this happens during power-on reset anyway (all values are
> > stored in shadow registers), I didn't see the point and dropped it for
> > now.
> > The shadow registers are clocked directly by the ungated ipg_root clock.
> 
> So, are you planning to drop the clocks property from the bindings too?

The gated clock input exists and is needed for the full functionality of
the device (writing and re-sensing fuses). It should be in the device
tree even if the linux driver doesn't implement writing.

regards
Philipp
Srinivas Kandagatla Aug. 7, 2015, 9:11 a.m. UTC | #5 
On 07/08/15 08:46, Philipp Zabel wrote:
>>> Nobody. I had initially copied the code that actually senses the fuses,
>>> > >but since this happens during power-on reset anyway (all values are
>>> > >stored in shadow registers), I didn't see the point and dropped it for
>>> > >now.
>>> > >The shadow registers are clocked directly by the ungated ipg_root clock.
>> >
>> >So, are you planning to drop the clocks property from the bindings too?
> The gated clock input exists and is needed for the full functionality of
> the device (writing and re-sensing fuses).
Thanks for clarification.

--srini
  It should be in the device
> tree even if the linux driver doesn't implement writing.
>
> regards
> Philipp
>
diff mbox

Patch

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 8db2978..0b33014 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -36,4 +36,15 @@  config NVMEM_SUNXI_SID
 	  This driver can also be built as a module. If so, the module
 	  will be called nvmem_sunxi_sid.
 
+config NVMEM_IMX_OCOTP
+	tristate "i.MX6 On-Chip OTP Controller support"
+	depends on SOC_IMX6
+	help
+	  This is a driver for the On-Chip OTP Controller (OCOTP) available on
+	  i.MX6 SoCs, providing access to 4 Kbits of one-time programmable
+	  eFuses.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nvmem-imx-ocotp.
+
 endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 4328b93..b512d77 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -10,3 +10,5 @@  obj-$(CONFIG_QCOM_QFPROM)	+= nvmem_qfprom.o
 nvmem_qfprom-y			:= qfprom.o
 obj-$(CONFIG_NVMEM_SUNXI_SID)	+= nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y		:= sunxi_sid.o
+obj-$(CONFIG_NVMEM_IMX_OCOTP)	+= nvmem-imx-ocotp.o
+nvmem-imx-ocotp-y		:= imx-ocotp.o
diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
new file mode 100644
index 0000000..e918967
--- /dev/null
+++ b/drivers/nvmem/imx-ocotp.c
@@ -0,0 +1,155 @@ 
+/*
+ * i.MX6 OCOTP fusebox driver
+ *
+ * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
+ *
+ * Based on the barebox ocotp driver,
+ * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
+ *	Orex Computed Radiography
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+struct ocotp_priv {
+	struct device *dev;
+	void __iomem *base;
+	unsigned int nregs;
+};
+
+static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
+			  void *val, size_t val_size)
+{
+	struct ocotp_priv *priv = context;
+	unsigned int offset = *(u32 *)reg;
+	unsigned int count;
+	int i;
+	u32 index;
+
+	index = offset >> 2;
+	count = val_size >> 2;
+
+	if (count > (priv->nregs - index))
+		count = priv->nregs - index;
+
+	for (i = index; i < (index + count); i++) {
+		*(u32 *)val = readl(priv->base + 0x400 + i * 0x10);
+		val += 4;
+	}
+
+	return (i - index) * 4;
+}
+
+static int imx_ocotp_write(void *context, const void *data, size_t count)
+{
+	/* Not implemented */
+	return 0;
+}
+
+static struct regmap_bus imx_ocotp_bus = {
+	.read = imx_ocotp_read,
+	.write = imx_ocotp_write,
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static bool imx_ocotp_writeable_reg(struct device *dev, unsigned int reg)
+{
+	return false;
+}
+
+static struct regmap_config imx_ocotp_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.writeable_reg = imx_ocotp_writeable_reg,
+	.name = "imx-ocotp",
+};
+
+static struct nvmem_config imx_ocotp_nvmem_config = {
+	.name = "imx-ocotp",
+	.read_only = true,
+	.owner = THIS_MODULE,
+};
+
+static const struct of_device_id imx_ocotp_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-ocotp",  (void *)128 },
+	{ .compatible = "fsl,imx6sl-ocotp", (void *)32 },
+	{ .compatible = "fsl,imx6sx-ocotp", (void *)128 },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
+
+static int imx_ocotp_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct regmap *regmap;
+	struct ocotp_priv *priv;
+	struct nvmem_device *nvmem;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	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;
+
+	regmap = devm_regmap_init(dev, &imx_ocotp_bus, priv,
+				  &imx_ocotp_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "regmap init failed\n");
+		return PTR_ERR(regmap);
+	}
+	imx_ocotp_nvmem_config.dev = dev;
+	nvmem = nvmem_register(&imx_ocotp_nvmem_config);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
+
+	platform_set_drvdata(pdev, nvmem);
+
+	return 0;
+}
+
+static int imx_ocotp_remove(struct platform_device *pdev)
+{
+	struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+	return nvmem_unregister(nvmem);
+}
+
+static struct platform_driver imx_ocotp_driver = {
+	.probe	= imx_ocotp_probe,
+	.remove	= imx_ocotp_remove,
+	.driver = {
+		.name	= "imx_ocotp",
+		.of_match_table = imx_ocotp_dt_ids,
+	},
+};
+module_platform_driver(imx_ocotp_driver);
+
+MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
+MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
+MODULE_LICENSE("GPL");