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SubjectRe: [PATCH v2 1/2] nvmem: Add driver for OCOTP in Sunplus SP7021
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On 07/12/2021 08:53, Vincent Shih wrote:
> Add driver for OCOTP in Sunplus SP7021
>
> Signed-off-by: Vincent Shih <vincent.sunplus@gmail.com>
> ---
> Changes in v2:
> - Merge sunplus-ocotp.h and sunplus-ocotp0.c to sunplus-ocotp.c
> - Clean up codes.
>
> MAINTAINERS | 5 +
> drivers/nvmem/Kconfig | 12 ++
> drivers/nvmem/Makefile | 2 +
> drivers/nvmem/sunplus-ocotp.c | 268 ++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 287 insertions(+)
> create mode 100644 drivers/nvmem/sunplus-ocotp.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 80eebc1..0e6593a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17947,6 +17947,11 @@ L: netdev@vger.kernel.org
> S: Maintained
> F: drivers/net/ethernet/dlink/sundance.c
>
> +SUNPLUS OCOTP DRIVER
> +M: Vincent Shih <vincent.sunplus@gmail.com>
> +S: Maintained
> +F: drivers/nvmem/sunplus-ocotp.c
> +
> SUPERH
> M: Yoshinori Sato <ysato@users.sourceforge.jp>
> M: Rich Felker <dalias@libc.org>
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index da41461..fb053d6 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -300,4 +300,16 @@ config NVMEM_BRCM_NVRAM
> This driver provides support for Broadcom's NVRAM that can be accessed
> using I/O mapping.
>
> +config NVMEM_SUNPLUS_OCOTP
> + tristate "Sunplus SoC OTP support"
> + depends on SOC_SP7021

COMPILE_TEST ?

> + depends on HAS_IOMEM
> + help
> + This is a driver for the On-chip OTP controller (OCOTP) available
> + on Sunplus SoCs. It provids access to 128 bytes of one-time

s/provids/provides

> + programmable eFuse.
> +
> + This driver can also be built as a module. If so, the module
> + will be called nvmem-sunplus-ocotp.
> +
> endif
> diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
> index dcbbde3..0f14cd9 100644
> --- a/drivers/nvmem/Makefile
> +++ b/drivers/nvmem/Makefile
> @@ -61,3 +61,5 @@ obj-$(CONFIG_NVMEM_RMEM) += nvmem-rmem.o
> nvmem-rmem-y := rmem.o
> obj-$(CONFIG_NVMEM_BRCM_NVRAM) += nvmem_brcm_nvram.o
> nvmem_brcm_nvram-y := brcm_nvram.o
> +obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP) += nvmem_sunplus_ocotp.o
> +nvmem_sunplus_ocotp-y := sunplus-ocotp.o
> diff --git a/drivers/nvmem/sunplus-ocotp.c b/drivers/nvmem/sunplus-ocotp.c
> new file mode 100644
> index 0000000..2997b29
> --- /dev/null
> +++ b/drivers/nvmem/sunplus-ocotp.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * The OCOTP driver for Sunplus SP7021
> + *
> + * Copyright (C) 2019 Sunplus Technology Inc., All rights reseerved.

reserved ?

> + */
> +
> +#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_device.h>
> +#include <linux/platform_device.h>
> +
> +/*
> + * OTP memory
> + * Each bank contains 4 words (32 bits).
> + * Bank 0 starts at offset 0 from the base.
> + */
> +
> +#define OTP_WORDS_PER_BANK 4
> +#define OTP_WORD_SIZE sizeof(u32)
> +#define OTP_BIT_ADDR_OF_BANK (8 * OTP_WORD_SIZE * OTP_WORDS_PER_BANK)
> +#define QAC628_OTP_NUM_BANKS 8
> +#define QAC628_OTP_SIZE (QAC628_OTP_NUM_BANKS * OTP_WORDS_PER_BANK * OTP_WORD_SIZE)
> +#define OTP_READ_TIMEOUT 20000
> +
> +/* HB_GPIO */
> +#define ADDRESS_8_DATA 0x20
> +
> +/* OTP_RX */
> +#define OTP_CONTROL_2 0x48
> +#define OTP_RD_PERIOD GENMASK(15, 8)
> +#define OTP_RD_PERIOD_MASK ~GENMASK(15, 8)
> +#define ONE_CPU_CLOCK 0x1
> +#define SEL_BAK_KEY2 BIT(5)
> +#define SEL_BAK_KEY2_MASK ~BIT(5)
> +#define SW_TRIM_EN BIT(4)
> +#define SW_TRIM_EN_MASK ~BIT(4)
> +#define SEL_BAK_KEY BIT(3)
> +#define SEL_BAK_KEY_MASK ~BIT(3)
> +#define OTP_READ BIT(2)
> +#define OTP_LOAD_SECURE_DATA BIT(1)
> +#define OTP_LOAD_SECURE_DATA_MASK ~BIT(1)
> +#define OTP_DO_CRC BIT(0)
> +#define OTP_DO_CRC_MASK ~BIT(0)
> +#define OTP_STATUS 0x4c
> +#define OTP_READ_DONE BIT(4)
> +#define OTP_READ_DONE_MASK ~BIT(4)
> +#define OTP_LOAD_SECURE_DONE_MASK ~BIT(2)
> +#define OTP_READ_ADDRESS 0x50
> +
> +enum base_type {
> + HB_GPIO,
> + OTPRX,
> + BASEMAX,
> +};
> +
> +struct sp_otp_data_t {
> + struct device *dev;
> + void __iomem *base[BASEMAX];
> + struct clk *clk;
> + struct nvmem_config *config;

totally redundant to store config in this stucture as you will never use
this after probe.

> +};
> +
> +struct sp_otp_vX_t {

does X needs to be caps?

> + int size;
> +};
> +
> +const struct sp_otp_vX_t sp_otp_v0 = {
> + .size = QAC628_OTP_SIZE,
> +};
> +
> +static int sp_otp_wait(void __iomem *reg_base)
> +{
> + int timeout = OTP_READ_TIMEOUT;
> + unsigned int status;
> +
> + do {
> + usleep_range(10);

Doesn't this take two arguments?

> + if (timeout-- == 0)
> + return -ETIMEDOUT;
> +
> + status = readl(reg_base + OTP_STATUS);
> + } while ((status & OTP_READ_DONE) != OTP_READ_DONE);
> +
> + return 0;
> +}
> +
> +static int sp_otp_read_real(struct sp_otp_data_t *otp, int addr, char *value)
> +{
> + unsigned int addr_data;
> + unsigned int byte_shift;
> + int ret = 0;

unnecessary initializatoin here.

> +
> + addr_data = addr % (OTP_WORD_SIZE * OTP_WORDS_PER_BANK);
> + addr_data = addr_data / OTP_WORD_SIZE;
> +
> + byte_shift = addr % (OTP_WORD_SIZE * OTP_WORDS_PER_BANK);
> + byte_shift = byte_shift % OTP_WORD_SIZE;
> +
> + addr = addr / (OTP_WORD_SIZE * OTP_WORDS_PER_BANK);
> + addr = addr * OTP_BIT_ADDR_OF_BANK;
> +
> + writel(readl(otp->base[OTPRX] + OTP_STATUS) & OTP_READ_DONE_MASK &
> + OTP_LOAD_SECURE_DONE_MASK, otp->base[OTPRX] + OTP_STATUS);
> + writel(addr, otp->base[OTPRX] + OTP_READ_ADDRESS);
> + writel(readl(otp->base[OTPRX] + OTP_CONTROL_2) | OTP_READ,
> + otp->base[OTPRX] + OTP_CONTROL_2);
> + writel(readl(otp->base[OTPRX] + OTP_CONTROL_2) & SEL_BAK_KEY2_MASK & SW_TRIM_EN_MASK
> + & SEL_BAK_KEY_MASK & OTP_LOAD_SECURE_DATA_MASK & OTP_DO_CRC_MASK,
> + otp->base[OTPRX] + OTP_CONTROL_2);
> + writel((readl(otp->base[OTPRX] + OTP_CONTROL_2) & OTP_RD_PERIOD_MASK) |
> + ((ONE_CPU_CLOCK * 0x1e) << 8), otp->base[OTPRX] + OTP_CONTROL_2);
> +
> + ret = sp_otp_wait(otp->base[OTPRX]);
> + if (ret < 0)
> + return ret;
> +
> + *value = (readl(otp->base[HB_GPIO] + ADDRESS_8_DATA + addr_data * OTP_WORD_SIZE)
> + >> (8 * byte_shift)) & 0xFF;
> +
> + return ret;
> +}
> +
> +static int sp_ocotp_read(void *priv, unsigned int offset, void *value, size_t bytes)
> +{
> + struct sp_otp_data_t *otp = priv;
> + unsigned int addr;
> + char *buf = value;
> + char val[4];
> + int ret;
> +
> + dev_dbg(otp->dev, "OTP read %u bytes at %u", bytes, offset);
> +
why do we need all these debug ?

> + if (offset >= QAC628_OTP_SIZE || bytes == 0 || ((offset + bytes) > QAC628_OTP_SIZE))
> + return -EINVAL;

Core should already do this sanity test, if not these checks belong to
nvmem core.

> +
> + ret = clk_enable(otp->clk);
> + if (ret)
> + return ret;
> +
> + *buf = 0;
> + for (addr = offset; addr < (offset + bytes); addr++) {
> + ret = sp_otp_read_real(otp, addr, val);
> + if (ret < 0) {
> + dev_err(otp->dev, "OTP read fail:%d at %d", ret, addr);
> + goto disable_clk;
> + }
> +
> + *buf++ = *val;
> + }
> +
> +disable_clk:
> + clk_disable(otp->clk);
> + dev_dbg(otp->dev, "OTP read complete");
> +
> + return ret;
> +}
> +
> +static struct nvmem_config sp_ocotp_nvmem_config = {
> + .name = "sp-ocotp",
> + .read_only = true,
> + .word_size = 1,
> + .size = QAC628_OTP_SIZE,
> + .stride = 1,
> + .reg_read = sp_ocotp_read,
> + .owner = THIS_MODULE,
> +};
> +
> +static int sp_ocotp_probe(struct platform_device *pdev)
> +{
> + const struct of_device_id *match;
> + const struct sp_otp_vX_t *sp_otp_vX;
> + struct device *dev = &pdev->dev;
> + struct nvmem_device *nvmem;
> + struct sp_otp_data_t *otp;
> + struct resource *res;
> + int ret;
> +

<---
> + match = of_match_device(dev->driver->of_match_table, dev);
> + if (match && match->data)
> + sp_otp_vX = match->data;
> + else
> + dev_err(dev, "OTP vX does not match");
--->

This looks like dead code, variable is set but not used anywhere.
Error case is ignored.


> +
> + otp = devm_kzalloc(dev, sizeof(*otp), GFP_KERNEL);
> + if (!otp)
> + return -ENOMEM;
> +
> + otp->dev = dev;
> + otp->config = &sp_ocotp_nvmem_config;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hb_gpio");
> + otp->base[HB_GPIO] = devm_ioremap_resource(dev, res);
> + if (IS_ERR(otp->base[HB_GPIO]))
> + return dev_err_probe(&pdev->dev, PTR_ERR(otp->base[HB_GPIO]),
> + "hb_gpio devm_ioremap_resource fail\n");

printing error here is totally redundant.

you could just do

if (IS_ERR(otp->base[HB_GPIO]))
return PTR_ERR(otp->base[HB_GPIO]);


> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otprx");
> + otp->base[OTPRX] = devm_ioremap_resource(dev, res);
> + if (IS_ERR(otp->base[OTPRX]))
> + return dev_err_probe(&pdev->dev, PTR_ERR(otp->base[OTPRX]),
> + "otprx devm_ioremap_resource fail\n");
> +
same here,

> + otp->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(otp->clk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(otp->clk),
> + "devm_clk_get fail\n");
> +
> + ret = clk_prepare(otp->clk);
> + if (ret < 0) {
> + dev_err(dev, "failed to prepare clk: %d\n", ret);
> + return ret;
> + }
> +
> + sp_ocotp_nvmem_config.priv = otp;
> + sp_ocotp_nvmem_config.dev = dev;
> +
> + nvmem = devm_nvmem_register(dev, &sp_ocotp_nvmem_config);
> + if (IS_ERR(nvmem))
> + return dev_err_probe(&pdev->dev, PTR_ERR(nvmem),
> + "register nvmem device fail\n");
> +
> + platform_set_drvdata(pdev, nvmem);
> +
> + dev_dbg(dev, "banks:%d x wpb:%d x wsize:%d = %d",
> + QAC628_OTP_NUM_BANKS, OTP_WORDS_PER_BANK,
> + OTP_WORD_SIZE, QAC628_OTP_SIZE);
> +
> + dev_info(dev, "by Sunplus (C) 2020");
> +
> + return 0;
> +}
> +
> +static const struct of_device_id sp_ocotp_dt_ids[] = {
> + { .compatible = "sunplus,sp7021-ocotp", .data = &sp_otp_v0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, sp_ocotp_dt_ids);
> +
> +static struct platform_driver sp_otp_driver = {
> + .probe = sp_ocotp_probe,
> + .driver = {
> + .name = "sunplus,sp7021-ocotp",
> + .of_match_table = sp_ocotp_dt_ids,
> + }
> +};
> +
> +static int __init sp_otp0_drv_new(void)
> +{
> + return platform_driver_register(&sp_otp_driver);
> +}
> +subsys_initcall(sp_otp0_drv_new);

Why this needs to be subsys_initcall() why can't it be module_init?


> +
> +static void __exit sp_otp0_drv_del(void)
> +{
> + platform_driver_unregister(&sp_otp_driver);
> +}
> +module_exit(sp_otp0_drv_del);
> +
> +MODULE_AUTHOR("Vincent Shih <vincent.sunplus@gmail.com>");
> +MODULE_DESCRIPTION("Sunplus On-Chip OTP driver");
> +MODULE_LICENSE("GPL v2");

Just GPL should be good here.

--srini
> +
>

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