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

From: [email-masked] (Srinivas Kandagatla)
Date: Thu, 06 Aug 2015 17:20:17 +0100

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 <[email-masked]>
> ---
> 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 <[email-masked]>
> + *
> + * Based on the barebox ocotp driver,
> + * Copyright (c) 2010 Baruch Siach <[email-masked]>,
> + *	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 <[email-masked]>");
> +MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
> +MODULE_LICENSE("GPL");

GPL v2 ?