hello
Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> 於 2021年12月9日 週四 下午11:50寫道：
>
>
>
> On 07/12/2021 08:53, Vincent Shih wrote:
> > Add driver for OCOTP in Sunplus SP7021
> >
> > Signed-off-by: Vincent Shih <vincent.sunplus@xxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxxxxxx
> > S: Maintained
> > F: drivers/net/ethernet/dlink/sundance.c
> >
> > +SUNPLUS OCOTP DRIVER
> > +M: Vincent Shih <vincent.sunplus@xxxxxxxxx>
> > +S: Maintained
> > +F: drivers/nvmem/sunplus-ocotp.c
> > +
> > SUPERH
> > M: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> > M: Rich Felker <dalias@xxxxxxxx>
> > 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 ?
>
Yes, I will add it.
> > + 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
>
Yes, I will modify it.
> > + 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 ?
>
Yes, I will modify it.
> > + */
> > +
> > +#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.
>
Yes, I will remove it.
> > +};
> > +
> > +struct sp_otp_vX_t {
>
> does X needs to be caps?
>
Yes, I will modify it.
> > + 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?
>
I will replace sp_otp_wait() with readl_poll_timeout().
> > + 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.
>
Yes, I will modify it.
> > +
> > + 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 ?
>
Yes, I will remove it.
> > + 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.
>
Yes, I will remove it.
> > +
> > + 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.
>
Yes, I will remove it.
>
> > +
> > + 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]);
>
Yes, I will modify it.
>
> > +
> > + 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,
>
Yes, I will modify it.
> > + 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?
>
The otp driver stores the mac address for the ethernet driver and
disconnect voltage for USB2 one.
Therefore, it must take priority over the other ones for the probe.
>
> > +
> > +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@xxxxxxxxx>");
> > +MODULE_DESCRIPTION("Sunplus On-Chip OTP driver");
> > +MODULE_LICENSE("GPL v2");
>
> Just GPL should be good here.
>
Yes, I will modify it.
> --srini
> > +
> >
Thanks for your review.
