Re: [PATCH V3 2/4] nvmem: imx: add i.MX8 nvmem driver

From: Srinivas Kandagatla
Date: Tue May 21 2019 - 04:35:22 EST




On 15/05/2019 08:53, Peng Fan wrote:
This patch adds i.MX8 nvmem ocotp driver to access fuse via
RPC to i.MX8 system controller.

Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
Cc: Fabio Estevam <festevam@xxxxxxxxx>
Cc: NXP Linux Team <linux-imx@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>

I don't see any dt-binding patches in my list. May be you forgot to add me in CC.

Can You please make sure that you add me to the cc of the dt-bindings patch so that I can take the driver and dt-bindings together via nvmem tree.
I will not be able to apply any driver patches without dt-bindings.

Thanks,
srini
---

V3:
Use imx_sc_msg_misc_fuse_read for req/resp
Drop uneccessary check
Drop the unnecessary type conversion
Minor fixes according to v2 comments

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 | 161 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 170 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..d9dc482ecb2f
--- /dev/null
+++ b/drivers/nvmem/imx-ocotp-scu.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * i.MX8 OCOTP fusebox driver
+ *
+ * Copyright 2019 NXP
+ *
+ * Peng Fan <peng.fan@xxxxxxx>
+ */
+
+#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_misc_fuse_read {
+ struct imx_sc_rpc_msg hdr;
+ u32 word;
+} __packed;
+
+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_misc_fuse_read msg;
+ struct imx_sc_rpc_msg *hdr = &msg.hdr;
+ int ret;
+
+ hdr->ver = IMX_SC_RPC_VERSION;
+ hdr->svc = IMX_SC_RPC_SVC_MISC;
+ hdr->func = IMX_SC_MISC_FUNC_OTP_FUSE_READ;
+ hdr->size = 2;
+
+ msg.word = word;
+
+ ret = imx_scu_call_rpc(ipc, &msg, true);
+ if (ret)
+ return ret;
+
+ *val = msg.word;
+
+ 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)) {
+ *buf++ = 0;
+ continue;
+ }
+ }
+
+ ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
+ if (ret) {
+ kfree(p);
+ return ret;
+ }
+ buf++;
+ }
+
+ memcpy(val, (u8 *)p + offset % 4, bytes);
+
+ 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.fan@xxxxxxx>");
+MODULE_DESCRIPTION("i.MX8 SCU OCOTP fuse box driver");
+MODULE_LICENSE("GPL v2");