Re: [PATCH v7 3/4] drivers: nvmem: Add Vybrid OCOTP support

From: maitysanchayan
Date: Mon Aug 10 2015 - 05:23:25 EST

Hello,

On 15-08-10 10:17:53, Srinivas Kandagatla wrote:
> Hi Sanchayan,
>
>
> Could you add Greg to the "to list" so that we can request him to pick
> this via his tree.

Will add Greg in cc with the next revision.

>
>
> Few nits, other than that driver looks good.
>
>
> On 06/08/15 16:27, Sanchayan Maity wrote:
> > The patch adds support for the On Chip One Time Programmable Peripheral
> > (OCOTP) on the Vybrid platform.
> >
> > Signed-off-by: Sanchayan Maity <maitysanchayan@xxxxxxxxx>
> > ---
> > drivers/nvmem/Kconfig | 10 ++
> > drivers/nvmem/Makefile | 2 +
> > drivers/nvmem/vf610-ocotp.c | 297 ++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 309 insertions(+)
> > create mode 100644 drivers/nvmem/vf610-ocotp.c
> >
> > diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> > index 0b33014..bfd0c02 100644
> > --- a/drivers/nvmem/Kconfig
> > +++ b/drivers/nvmem/Kconfig
> > @@ -47,4 +47,14 @@ config NVMEM_IMX_OCOTP
> > This driver can also be built as a module. If so, the module
> > will be called nvmem-imx-ocotp.
> >
> > +config NVMEM_VF610_OCOTP
> > + tristate "VF610_SoCs OCOTP support"
> > + depends on SOC_VF610
> You could also add COMPILE_TEST which will ensure that its compile checked.

Ok.

> > + help
> > + This is a driver for the 'OCOTP' peripheral available on Vybrid
> > + devices like VF5xx and VF6xx.
> > +
> > + This driver can also be built as a module. If so, the module will
> > + be called nvmem-vf610-ocotp.
> > +
> > endif
> > diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
> > index b512d77..8a1eea8 100644
> > --- a/drivers/nvmem/Makefile
> > +++ b/drivers/nvmem/Makefile
> > @@ -12,3 +12,5 @@ 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
> > +obj-$(CONFIG_NVMEM_VF610_OCOTP) += nvmem-vf610-ocotp.o
> > +nvmem-vf610-ocotp-y := vf610-ocotp.o
> > diff --git a/drivers/nvmem/vf610-ocotp.c b/drivers/nvmem/vf610-ocotp.c
> > new file mode 100644
> > index 0000000..25ee701
> > --- /dev/null
> > +++ b/drivers/nvmem/vf610-ocotp.c
> > @@ -0,0 +1,297 @@
> > +/*
> > + * Copyright (C) 2015 Toradex AG.
> > + *
> > + * Author: Sanchayan Maity <sanchayan.maity@xxxxxxxxxxx>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 and
> > + * only version 2 as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/delay.h>
> > +#include <linux/device.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/nvmem-provider.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> > +
> > +/* OCOTP Register Offsets */
> > +#define OCOTP_CTRL_REG 0x00
> > +#define OCOTP_CTRL_SET 0x04
> > +#define OCOTP_CTRL_CLR 0x08
> > +#define OCOTP_TIMING 0x10
> > +#define OCOTP_DATA 0x20
> > +#define OCOTP_READ_CTRL_REG 0x30
> > +#define OCOTP_READ_FUSE_DATA 0x40
> > +
> > +/* OCOTP Register bits and masks */
> > +#define OCOTP_CTRL_WR_UNLOCK 16
> > +#define OCOTP_CTRL_WR_UNLOCK_KEY 0x3E77
> > +#define OCOTP_CTRL_WR_UNLOCK_MASK 0xFFFF0000
> > +#define OCOTP_CTRL_ADDR 0
> > +#define OCOTP_CTRL_ADDR_MASK 0x7F
> > +#define OCOTP_CTRL_RELOAD_SHADOWS (0x1 << 10)
> > +#define OCOTP_CTRL_ERROR (0x1 << 9)
> > +#define OCOTP_CTRL_BUSY (0x1 << 8)
>
> we can use BIT and GENMASK variants here for most of the defines.

Ok.

> > +
> > +#define OCOTP_TIMING_STROBE_READ 16
> > +#define OCOTP_TIMING_STROBE_READ_MASK 0x003F0000
> > +#define OCOTP_TIMING_RELAX 12
> > +#define OCOTP_TIMING_RELAX_MASK 0x0000F000
> > +#define OCOTP_TIMING_STROBE_PROG 0
> > +#define OCOTP_TIMING_STROBE_PROG_MASK 0x00000FFF
> > +
> > +#define OCOTP_READ_CTRL_READ_FUSE 0x1
> > +
> > +#define VF610_OCOTP_TIMEOUT 100000
> > +
> > +#define BF(value, field) (((value) << field) & field##_MASK)
> > +
> > +#define DEF_RELAX 20
> > +
> > +static const int base_to_fuse_addr_mappings[][2] = {
> > + {0x400, 0x00},
> > + {0x410, 0x01},
> > + {0x420, 0x02},
> > + {0x450, 0x05},
> > + {0x4F0, 0x0F},
> > + {0x600, 0x20},
> > + {0x610, 0x21},
> > + {0x620, 0x22},
> > + {0x630, 0x23},
> > + {0x640, 0x24},
> > + {0x650, 0x25},
> > + {0x660, 0x26},
> > + {0x670, 0x27},
> > + {0x6F0, 0x2F},
> > + {0x880, 0x38},
> > + {0x890, 0x39},
> > + {0x8A0, 0x3A},
> > + {0x8B0, 0x3B},
> > + {0x8C0, 0x3C},
> > + {0x8D0, 0x3D},
> > + {0x8E0, 0x3E},
> > + {0x8F0, 0x3F},
> > + {0xC80, 0x78},
> > + {0xC90, 0x79},
> > + {0xCA0, 0x7A},
> > + {0xCB0, 0x7B},
> > + {0xCC0, 0x7C},
> > + {0xCD0, 0x7D},
> > + {0xCE0, 0x7E},
> > + {0xCF0, 0x7F},
> > +};
> > +
> > +struct vf610_ocotp {
> > + void __iomem *base;
> > + struct clk *clk;
> > + struct device *dev;
> > + struct nvmem_device *nvmem;
> > + int timing;
> > +};
> > +
> > +static int vf610_ocotp_wait_busy(void __iomem *base)
> > +{
> > + int timeout = VF610_OCOTP_TIMEOUT;
> > +
> > + while ((readl(base) & OCOTP_CTRL_BUSY) && --timeout)
> > + udelay(10);
> > +
> > + if (!timeout) {
> > + writel(OCOTP_CTRL_ERROR, base + OCOTP_CTRL_CLR);
> > + return -ETIMEDOUT;
> > + }
> > +
> > + udelay(10);
> > +
> > + return 0;
> > +}
> > +
> > +static int vf610_ocotp_calculate_timing(struct vf610_ocotp *ocotp_dev)
> > +{
> > + u32 clk_rate;
> > + u32 relax, strobe_read, strobe_prog;
> > + u32 timing;
> > +
> > + clk_rate = clk_get_rate(ocotp_dev->clk);
> > +
> > + /* Refer section OTP read/write timing parameters in TRM */
> > + relax = clk_rate / (1000000000 / DEF_RELAX) - 1;
> > + strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1;
> > + strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1;
> > +
> > + timing = BF(relax, OCOTP_TIMING_RELAX);
> > + timing |= BF(strobe_read, OCOTP_TIMING_STROBE_READ);
> > + timing |= BF(strobe_prog, OCOTP_TIMING_STROBE_PROG);
> > +
> > + return timing;
> > +}
> > +
> > +static int vf610_get_fuse_address(int base_addr_offset)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(base_to_fuse_addr_mappings); i++) {
> > + if (base_to_fuse_addr_mappings[i][0] == base_addr_offset)
> > + return base_to_fuse_addr_mappings[i][1];
> > + }
> > +
> > + return -EINVAL;
> > +}
> > +
> > +static int vf610_ocotp_write(void *context, const void *data, size_t count)
> > +{
> > + return 0;
> > +}
> > +
> > +static int vf610_ocotp_read(void *context,
> > + const void *off, size_t reg_size,
> > + void *val, size_t val_size)
> Align it to the braces.

Ok.

> > +{
> > + struct vf610_ocotp *ocotp = context;
> > + unsigned int offset = *(u32 *)off;
> > + u32 reg, *buf = val;
> > + int fuse_addr;
> > + int ret;
> > +
> > + while (val_size > 0) {
> > + fuse_addr = vf610_get_fuse_address(offset);
> > + if (fuse_addr > 0) {
> > + writel(ocotp->timing, ocotp->base + OCOTP_TIMING);
> > + ret = vf610_ocotp_wait_busy(ocotp->base + OCOTP_CTRL_REG);
> > + if (ret)
> > + return ret;
> > +
> > + reg = readl(ocotp->base + OCOTP_CTRL_REG);
> > + reg &= ~OCOTP_CTRL_ADDR_MASK;
> > + reg &= ~OCOTP_CTRL_WR_UNLOCK_MASK;
> > + reg |= BF(fuse_addr, OCOTP_CTRL_ADDR);
> > + writel(reg, ocotp->base + OCOTP_CTRL_REG);
> > +
> > + writel(OCOTP_READ_CTRL_READ_FUSE,
> > + ocotp->base + OCOTP_READ_CTRL_REG);
> > + ret = vf610_ocotp_wait_busy(ocotp->base + OCOTP_CTRL_REG);
> > + if (ret)
> > + return ret;
> > +
> > + if (readl(ocotp->base) & OCOTP_CTRL_ERROR) {
> > + dev_dbg(ocotp->dev, "Error reading from fuse address %x\n",
> > + fuse_addr);
> > + writel(OCOTP_CTRL_ERROR, ocotp->base + OCOTP_CTRL_CLR);
> > + }
> > +
> > + /*
> > + * In case of error, we do not abort and expect to read
> > + * 0xBADABADA as mentioned by the TRM. We just read this
> > + * value and return.
> > + */
> > + *buf = readl(ocotp->base + OCOTP_READ_FUSE_DATA);
> > + } else {
> > + *buf = 0;
> > + }
> > +
> > + buf++;
> > + val_size--;
> > + offset += reg_size;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static struct regmap_bus vf610_ocotp_bus = {
> > + .read = vf610_ocotp_read,
> > + .write = vf610_ocotp_write,
> > + .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
> > + .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
> > +};
> > +
> > +static struct regmap_config ocotp_regmap_config = {
> > + .reg_bits = 32,
> > + .val_bits = 32,
> > + .reg_stride = 4,
> > + .max_register = 0xCF0,
> Cant we get this info from the resource_size() ?

Yes we can. I will change to that.

Thanks for the review.

- Sanchayan.

> > +};
> > +
> > +static struct nvmem_config ocotp_config = {
> > + .name = "ocotp",
> > + .owner = THIS_MODULE,
> > +};
> > +
> > +static const struct of_device_id ocotp_of_match[] = {
> > + { .compatible = "fsl,vf610-ocotp", },
> > + {/* sentinel */},
> > +};
> > +MODULE_DEVICE_TABLE(of, ocotp_of_match);
> > +
> > +static int vf610_ocotp_remove(struct platform_device *pdev)
> > +{
> > + struct vf610_ocotp *ocotp_dev = platform_get_drvdata(pdev);
> > +
> > + return nvmem_unregister(ocotp_dev->nvmem);
> > +}
> > +
> > +static int vf610_ocotp_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct resource *res;
> > + struct regmap *regmap;
> > + struct vf610_ocotp *ocotp_dev;
> > +
> > + ocotp_dev = devm_kzalloc(&pdev->dev,
> > + sizeof(struct vf610_ocotp), GFP_KERNEL);
> > + if (!ocotp_dev)
> > + return -ENOMEM;
> > +
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + ocotp_dev->base = devm_ioremap_resource(dev, res);
> > + if (IS_ERR(ocotp_dev->base))
> > + return PTR_ERR(ocotp_dev->base);
> > +
> > + ocotp_dev->clk = devm_clk_get(dev, "ocotp");
> > + if (IS_ERR(ocotp_dev->clk)) {
> > + dev_err(dev, "failed getting clock, err = %ld\n",
> > + PTR_ERR(ocotp_dev->clk));
> > + return PTR_ERR(ocotp_dev->clk);
> > + }
> > +
> > + regmap = devm_regmap_init(dev,
> > + &vf610_ocotp_bus, ocotp_dev, &ocotp_regmap_config);
> > + if (IS_ERR(regmap)) {
> > + dev_err(dev, "regmap init failed\n");
> > + return PTR_ERR(regmap);
> > + }
> > + ocotp_config.dev = dev;
> > +
> > + ocotp_dev->nvmem = nvmem_register(&ocotp_config);
> > + if (IS_ERR(ocotp_dev->nvmem))
> > + return PTR_ERR(ocotp_dev->nvmem);
> > +
> > + ocotp_dev->dev = dev;
> > + platform_set_drvdata(pdev, ocotp_dev);
> > +
> > + ocotp_dev->timing = vf610_ocotp_calculate_timing(ocotp_dev);
> > +
> > + return 0;
> > +}
> > +
> > +static struct platform_driver vf610_ocotp_driver = {
> > + .probe = vf610_ocotp_probe,
> > + .remove = vf610_ocotp_remove,
> > + .driver = {
> > + .name = "vf610-ocotp",
> > + .of_match_table = ocotp_of_match,
> > + },
> > +};
> > +module_platform_driver(vf610_ocotp_driver);
> > +MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@xxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("Vybrid OCOTP driver");
> > +MODULE_LICENSE("GPL v2");
> >
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