[PATCH V2 1/2] nvmem: imx: scu: support hole region check

[PATCH V2 1/2] nvmem: imx: scu: support hole region check

[Peng Fan]

From: Peng Fan <peng.fan@nxp.com>

Introduce HOLE/ECC_REGION flag and in_hole helper to ease the check
of hole region. The ECC_REGION is also introduced here which is
preparing for programming support. ECC_REGION could only be programmed
once, so need take care.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---

V2:
 Rebased on latest linux-next

 drivers/nvmem/imx-ocotp-scu.c | 47 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 42 insertions(+), 5 deletions(-)

diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
index 61a17f943f47..030e27ba4dfb 100644
--- a/drivers/nvmem/imx-ocotp-scu.c
+++ b/drivers/nvmem/imx-ocotp-scu.c
@@ -19,9 +19,20 @@ enum ocotp_devtype {
 	IMX8QM,
 };
 
+#define ECC_REGION	BIT(0)
+#define HOLE_REGION	BIT(1)
+
+struct ocotp_region {
+	u32 start;
+	u32 end;
+	u32 flag;
+};
+
 struct ocotp_devtype_data {
 	int devtype;
 	int nregs;
+	u32 num_region;
+	struct ocotp_region region[];
 };
 
 struct ocotp_priv {
@@ -38,13 +49,41 @@ struct imx_sc_msg_misc_fuse_read {
 static struct ocotp_devtype_data imx8qxp_data = {
 	.devtype = IMX8QXP,
 	.nregs = 800,
+	.num_region = 3,
+	.region = {
+		{0x10, 0x10f, ECC_REGION},
+		{0x110, 0x21F, HOLE_REGION},
+		{0x220, 0x31F, ECC_REGION},
+	},
 };
 
 static struct ocotp_devtype_data imx8qm_data = {
 	.devtype = IMX8QM,
 	.nregs = 800,
+	.num_region = 2,
+	.region = {
+		{0x10, 0x10f, ECC_REGION},
+		{0x1a0, 0x1ff, ECC_REGION},
+	},
 };
 
+static bool in_hole(void *context, u32 index)
+{
+	struct ocotp_priv *priv = context;
+	const struct ocotp_devtype_data *data = priv->data;
+	int i;
+
+	for (i = 0; i < data->num_region; i++) {
+		if (data->region[i].flag & HOLE_REGION) {
+			if ((index >= data->region[i].start) &&
+			    (index <= data->region[i].end))
+				return true;
+		}
+	}
+
+	return false;
+}
+
 static int imx_sc_misc_otp_fuse_read(struct imx_sc_ipc *ipc, u32 word,
 				     u32 *val)
 {
@@ -91,11 +130,9 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
 	buf = p;
 
 	for (i = index; i < (index + count); i++) {
-		if (priv->data->devtype == IMX8QXP) {
-			if ((i > 271) && (i < 544)) {
-				*buf++ = 0;
-				continue;
-			}
+		if (in_hole(context, i)) {
+			*buf++ = 0;
+			continue;
 		}
 
 		ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
-- 
2.16.4

[PATCH V2 2/2] nvmem: imx: scu: support write

[Peng Fan]

From: Peng Fan <peng.fan@nxp.com>

The fuse programming from non-secure world is blocked, so we could
only use Arm Trusted Firmware SIP call to let ATF program fuse.

Because there is ECC region that could only be programmed once,
so add a heler in_ecc to check the ecc region.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---

V2:
 Rebased on Latest linux-next

 drivers/nvmem/imx-ocotp-scu.c | 73 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 72 insertions(+), 1 deletion(-)

diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
index 030e27ba4dfb..03f1ab23ad51 100644
--- a/drivers/nvmem/imx-ocotp-scu.c
+++ b/drivers/nvmem/imx-ocotp-scu.c
@@ -7,6 +7,7 @@
  * Peng Fan <peng.fan@nxp.com>
  */
 
+#include <linux/arm-smccc.h>
 #include <linux/firmware/imx/sci.h>
 #include <linux/module.h>
 #include <linux/nvmem-provider.h>
@@ -14,6 +15,9 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+#define IMX_SIP_OTP			0xC200000A
+#define IMX_SIP_OTP_WRITE		0x2
+
 enum ocotp_devtype {
 	IMX8QXP,
 	IMX8QM,
@@ -46,6 +50,8 @@ struct imx_sc_msg_misc_fuse_read {
 	u32 word;
 } __packed;
 
+static DEFINE_MUTEX(scu_ocotp_mutex);
+
 static struct ocotp_devtype_data imx8qxp_data = {
 	.devtype = IMX8QXP,
 	.nregs = 800,
@@ -84,6 +90,23 @@ static bool in_hole(void *context, u32 index)
 	return false;
 }
 
+static bool in_ecc(void *context, u32 index)
+{
+	struct ocotp_priv *priv = context;
+	const struct ocotp_devtype_data *data = priv->data;
+	int i;
+
+	for (i = 0; i < data->num_region; i++) {
+		if (data->region[i].flag & ECC_REGION) {
+			if ((index >= data->region[i].start) &&
+			    (index <= data->region[i].end))
+				return true;
+		}
+	}
+
+	return false;
+}
+
 static int imx_sc_misc_otp_fuse_read(struct imx_sc_ipc *ipc, u32 word,
 				     u32 *val)
 {
@@ -127,6 +150,8 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
 	if (!p)
 		return -ENOMEM;
 
+	mutex_lock(&scu_ocotp_mutex);
+
 	buf = p;
 
 	for (i = index; i < (index + count); i++) {
@@ -137,6 +162,7 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
 
 		ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
 		if (ret) {
+			mutex_unlock(&scu_ocotp_mutex);
 			kfree(p);
 			return ret;
 		}
@@ -145,18 +171,63 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
 
 	memcpy(val, (u8 *)p + offset % 4, bytes);
 
+	mutex_unlock(&scu_ocotp_mutex);
+
 	kfree(p);
 
 	return 0;
 }
 
+static int imx_scu_ocotp_write(void *context, unsigned int offset,
+			       void *val, size_t bytes)
+{
+	struct ocotp_priv *priv = context;
+	struct arm_smccc_res res;
+	u32 *buf = val;
+	u32 tmp;
+	u32 index;
+	int ret;
+
+	/* allow only writing one complete OTP word at a time */
+	if ((bytes != 4) || (offset % 4))
+		return -EINVAL;
+
+	index = offset >> 2;
+
+	if (in_hole(context, index))
+		return -EINVAL;
+
+	if (in_ecc(context, index)) {
+		pr_warn("ECC region, only program once\n");
+		mutex_lock(&scu_ocotp_mutex);
+		ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, index, &tmp);
+		mutex_unlock(&scu_ocotp_mutex);
+		if (ret)
+			return ret;
+		if (tmp) {
+			pr_warn("ECC region, already has value: %x\n", tmp);
+			return -EIO;
+		}
+	}
+
+	mutex_lock(&scu_ocotp_mutex);
+
+	arm_smccc_smc(IMX_SIP_OTP, IMX_SIP_OTP_WRITE, index, *buf,
+		      0, 0, 0, 0, &res);
+
+	mutex_unlock(&scu_ocotp_mutex);
+
+	return res.a0;
+}
+
 static struct nvmem_config imx_scu_ocotp_nvmem_config = {
 	.name = "imx-scu-ocotp",
-	.read_only = true,
+	.read_only = false,
 	.word_size = 4,
 	.stride = 1,
 	.owner = THIS_MODULE,
 	.reg_read = imx_scu_ocotp_read,
+	.reg_write = imx_scu_ocotp_write,
 };
 
 static const struct of_device_id imx_scu_ocotp_dt_ids[] = {
-- 
2.16.4

Re: [PATCH V2 1/2] nvmem: imx: scu: support hole region check

[Srinivas Kandagatla]

On 27/09/2019 03:23, Peng Fan wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> Introduce HOLE/ECC_REGION flag and in_hole helper to ease the check
> of hole region. The ECC_REGION is also introduced here which is
> preparing for programming support. ECC_REGION could only be programmed
> once, so need take care.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
> 
> V2:
>   Rebased on latest linux-next
> 
>   drivers/nvmem/imx-ocotp-scu.c | 47 ++++++++++++++++++++++++++++++++++++++-----
>   1 file changed, 42 insertions(+), 5 deletions(-)

thanks, applied both.

--srini
> 
> diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
> index 61a17f943f47..030e27ba4dfb 100644
> --- a/drivers/nvmem/imx-ocotp-scu.c
> +++ b/drivers/nvmem/imx-ocotp-scu.c
> @@ -19,9 +19,20 @@ enum ocotp_devtype {
>   	IMX8QM,
>   };
>   
> +#define ECC_REGION	BIT(0)
> +#define HOLE_REGION	BIT(1)
> +
> +struct ocotp_region {
> +	u32 start;
> +	u32 end;
> +	u32 flag;
> +};
> +
>   struct ocotp_devtype_data {
>   	int devtype;
>   	int nregs;
> +	u32 num_region;
> +	struct ocotp_region region[];
>   };
>   
>   struct ocotp_priv {
> @@ -38,13 +49,41 @@ struct imx_sc_msg_misc_fuse_read {
>   static struct ocotp_devtype_data imx8qxp_data = {
>   	.devtype = IMX8QXP,
>   	.nregs = 800,
> +	.num_region = 3,
> +	.region = {
> +		{0x10, 0x10f, ECC_REGION},
> +		{0x110, 0x21F, HOLE_REGION},
> +		{0x220, 0x31F, ECC_REGION},
> +	},
>   };
>   
>   static struct ocotp_devtype_data imx8qm_data = {
>   	.devtype = IMX8QM,
>   	.nregs = 800,
> +	.num_region = 2,
> +	.region = {
> +		{0x10, 0x10f, ECC_REGION},
> +		{0x1a0, 0x1ff, ECC_REGION},
> +	},
>   };
>   
> +static bool in_hole(void *context, u32 index)
> +{
> +	struct ocotp_priv *priv = context;
> +	const struct ocotp_devtype_data *data = priv->data;
> +	int i;
> +
> +	for (i = 0; i < data->num_region; i++) {
> +		if (data->region[i].flag & HOLE_REGION) {
> +			if ((index >= data->region[i].start) &&
> +			    (index <= data->region[i].end))
> +				return true;
> +		}
> +	}
> +
> +	return false;
> +}
> +
>   static int imx_sc_misc_otp_fuse_read(struct imx_sc_ipc *ipc, u32 word,
>   				     u32 *val)
>   {
> @@ -91,11 +130,9 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
>   	buf = p;
>   
>   	for (i = index; i < (index + count); i++) {
> -		if (priv->data->devtype == IMX8QXP) {
> -			if ((i > 271) && (i < 544)) {
> -				*buf++ = 0;
> -				continue;
> -			}
> +		if (in_hole(context, i)) {
> +			*buf++ = 0;
> +			continue;
>   		}
>   
>   		ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
>