> From: Peng Fan
> Sent: Wednesday, May 8, 2019 10:56 AM
>
> This patch adds i.MX8 nvmem ocotp driver to access fuse via RPC to i.MX8
> system controller.
>
> Cc: Srinivas Kandagatla <srinivas.kandaga...@linaro.org>
> Cc: Shawn Guo <shawn...@kernel.org>
> Cc: Sascha Hauer <s.ha...@pengutronix.de>
> Cc: Pengutronix Kernel Team <ker...@pengutronix.de>
> Cc: Fabio Estevam <feste...@gmail.com>
> Cc: NXP Linux Team <linux-...@nxp.com>
> Cc: linux-arm-ker...@lists.infradead.org
> Signed-off-by: Peng Fan <peng....@nxp.com>
> ---
>
> V2:
> Add "scu" or "SCU", Add imx_sc_misc_otp_fuse_read, minor fixes
>
> drivers/nvmem/Kconfig | 7 ++
> drivers/nvmem/Makefile | 2 +
> drivers/nvmem/imx-ocotp-scu.c | 170
> ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 179 insertions(+)
> create mode 100644 drivers/nvmem/imx-ocotp-scu.c
>
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index
> 530d570724c9..79afe44195a1 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -36,6 +36,13 @@ 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_IMX_OCOTP_SCU
> + tristate "i.MX8 SCU On-Chip OTP Controller support"
> + depends on IMX_SCU
> + help
> + This is a driver for the SCU On-Chip OTP Controller (OCOTP)
> + available on i.MX8 SoCs.
> +
> config NVMEM_LPC18XX_EEPROM
> tristate "NXP LPC18XX EEPROM Memory Support"
> depends on ARCH_LPC18XX || COMPILE_TEST diff --git
> a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile index
> 2ece8ffffdda..30d653d34e57 100644
> --- a/drivers/nvmem/Makefile
> +++ b/drivers/nvmem/Makefile
> @@ -13,6 +13,8 @@ obj-$(CONFIG_NVMEM_IMX_IIM) +=
> nvmem-imx-iim.o
> nvmem-imx-iim-y := imx-iim.o
> obj-$(CONFIG_NVMEM_IMX_OCOTP) += nvmem-imx-ocotp.o
> nvmem-imx-ocotp-y := imx-ocotp.o
> +obj-$(CONFIG_NVMEM_IMX_OCOTP_SCU) += nvmem-imx-ocotp-scu.o
> +nvmem-imx-ocotp-scu-y := imx-ocotp-scu.o
> obj-$(CONFIG_NVMEM_LPC18XX_EEPROM) +=
> nvmem_lpc18xx_eeprom.o
> nvmem_lpc18xx_eeprom-y := lpc18xx_eeprom.o
> obj-$(CONFIG_NVMEM_LPC18XX_OTP) += nvmem_lpc18xx_otp.o
> diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
> new file mode 100644 index 000000000000..038e744c8588
> --- /dev/null
> +++ b/drivers/nvmem/imx-ocotp-scu.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * i.MX8 OCOTP fusebox driver
> + *
> + * Copyright 2019 NXP
> + *
> + * Peng Fan <peng....@nxp.com>
> + */
> +
> +#include <linux/firmware/imx/sci.h>
> +#include <linux/module.h>
> +#include <linux/nvmem-provider.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +enum ocotp_devtype {
> + IMX8QXP,
> +};
> +
> +struct ocotp_devtype_data {
> + int devtype;
> + int nregs;
> +};
> +
> +struct ocotp_priv {
> + struct device *dev;
> + const struct ocotp_devtype_data *data;
> + struct imx_sc_ipc *nvmem_ipc;
> +};
> +
> +struct imx_sc_msg_req_misc_fuse_read {
> + struct imx_sc_rpc_msg hdr;
> + u32 word;
> +} __packed;
> +
> +struct imx_sc_msg_resp_misc_fuse_read {
> + struct imx_sc_rpc_msg hdr;
> + u32 val;
> +} __packed;
> +
How about
struct imx_sc_msg_misc_fuse_read {
struct imx_sc_rpc_msg hdr;
union {
u32 word;
u32 val;
} data;
} __packed;
Then we can save one struct and convert.
> +static struct ocotp_devtype_data imx8qxp_data = {
> + .devtype = IMX8QXP,
> + .nregs = 800,
> +};
> +
> +static int imx_sc_misc_otp_fuse_read(struct imx_sc_ipc *ipc, u32 word,
> + u32 *val)
> +{
> + struct imx_sc_msg_req_misc_fuse_read msg;
> + struct imx_sc_msg_resp_misc_fuse_read *resp;
> + struct imx_sc_rpc_msg *hdr = &msg.hdr;
> + int ret;
> +
> + hdr->ver = IMX_SC_RPC_VERSION;
> + hdr->svc = (uint8_t)IMX_SC_RPC_SVC_MISC;
> + hdr->func = (uint8_t)IMX_SC_MISC_FUNC_OTP_FUSE_READ;
Pls drop the unnecessary type conversion.
> + hdr->size = 2;
> +
> + msg.word = word;
> +
> + ret = imx_scu_call_rpc(ipc, &msg, true);
> + if (ret)
> + return ret;
> +
> + resp = (struct imx_sc_msg_resp_misc_fuse_read *)&msg;
> + if (val != NULL)
Drop this unnecessary check
> + *val = resp->val;
> +
> + return 0;
> +}
> +
> +static int imx_scu_ocotp_read(void *context, unsigned int offset,
> + void *val, size_t bytes)
> +{
> + struct ocotp_priv *priv = context;
> + u32 count, index, num_bytes;
> + u32 *buf;
> + void *p;
> + int i, ret;
> +
> + index = offset >> 2;
> + num_bytes = round_up((offset % 4) + bytes, 4);
> + count = num_bytes >> 2;
> +
> + if (count > (priv->data->nregs - index))
> + count = priv->data->nregs - index;
> +
> + p = kzalloc(num_bytes, GFP_KERNEL);
> + if (!p)
> + return -ENOMEM;
> +
> + buf = p;
> +
> + for (i = index; i < (index + count); i++) {
> + if (priv->data->devtype == IMX8QXP) {
> + if ((i > 271) && (i < 544)) {
> + *(u32 *)buf = 0;
Still need convert?
> + buf += 4;
I'm not sure this is right
Shouldn't it be buf++ ?
> + continue;
> + }
> + }
> +
> + ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
> + if (ret) {
> + kfree(p);
> + return ret;
> + }
> + buf++;
> + }
> +
> + memcpy(val, p + offset % 4, bytes);
Is there a build warning?
I wonder a more safe way maybe:
memcpy(val, (u8 *)p + offset % 4, byptes);
Regards
Dong Aisheng
> +
> + kfree(p);
> +
> + return 0;
> +}
> +
> +static struct nvmem_config imx_scu_ocotp_nvmem_config = {
> + .name = "imx-scu-ocotp",
> + .read_only = true,
> + .word_size = 4,
> + .stride = 1,
> + .owner = THIS_MODULE,
> + .reg_read = imx_scu_ocotp_read,
> +};
> +
> +static const struct of_device_id imx_scu_ocotp_dt_ids[] = {
> + { .compatible = "fsl,imx8qxp-scu-ocotp", (void *)&imx8qxp_data },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, imx_scu_ocotp_dt_ids);
> +
> +static int imx_scu_ocotp_probe(struct platform_device *pdev) {
> + struct device *dev = &pdev->dev;
> + struct ocotp_priv *priv;
> + struct nvmem_device *nvmem;
> + int ret;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + ret = imx_scu_get_handle(&priv->nvmem_ipc);
> + if (ret)
> + return ret;
> +
> + priv->data = of_device_get_match_data(dev);
> + priv->dev = dev;
> + imx_scu_ocotp_nvmem_config.size = 4 * priv->data->nregs;
> + imx_scu_ocotp_nvmem_config.dev = dev;
> + imx_scu_ocotp_nvmem_config.priv = priv;
> + nvmem = devm_nvmem_register(dev, &imx_scu_ocotp_nvmem_config);
> +
> + return PTR_ERR_OR_ZERO(nvmem);
> +}
> +
> +static struct platform_driver imx_scu_ocotp_driver = {
> + .probe = imx_scu_ocotp_probe,
> + .driver = {
> + .name = "imx_scu_ocotp",
> + .of_match_table = imx_scu_ocotp_dt_ids,
> + },
> +};
> +module_platform_driver(imx_scu_ocotp_driver);
> +
> +MODULE_AUTHOR("Peng Fan <peng....@nxp.com>");
> +MODULE_DESCRIPTION("i.MX8 SCU OCOTP fuse box driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.16.4
