Re: [PATCH] ARM: mxs: Add serial number support for i.MX23, i.MX28 SoCs

From: Shawn Guo
Date: Mon Nov 16 2020 - 03:10:54 EST


On Wed, Nov 11, 2020 at 08:18:59AM +0300, Ivan Zaentsev wrote:
> i.MX23 and i.MX28 SoCs unique identifiers are factory-programmed
> in On-Chip OTP memory. i.MX28's 64-bit unique id is in
> HW_OCOTP_OPS2:HW_OCOTP_OPS3 (see MCIMX28 Ref. Man., sec. 20.4.22-23).
>
> i.MX23 provides 32-bit long unique id in HW_OCOTP_OPS3.
> Though not clearly documented, there is a clue in sec. 35.9.3.
>
> The unique id is reported in /sys/devices/soc0/serial_number
> and in /proc/cpuinfo
>
> Signed-off-by: Ivan Zaentsev <ivan.zaentsev@xxxxxxxxxxxxx>
> Suggested-by: Evgeny Boger <boger@xxxxxxxxxxxxxx>
> ---
> arch/arm/mach-mxs/mach-mxs.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/arch/arm/mach-mxs/mach-mxs.c b/arch/arm/mach-mxs/mach-mxs.c
> index c109f47e9cbc..af96368cc16a 100644
> --- a/arch/arm/mach-mxs/mach-mxs.c
> +++ b/arch/arm/mach-mxs/mach-mxs.c
> @@ -23,6 +23,7 @@
> #include <asm/mach/map.h>
> #include <asm/mach/time.h>
> #include <asm/system_misc.h>
> +#include <asm/system_info.h>

Can we move it above <asm/system_misc.h> to get them alphabetically
sorted?

>
> #include "pm.h"
>
> @@ -51,6 +52,9 @@
> #define MXS_CLR_ADDR 0x8
> #define MXS_TOG_ADDR 0xc
>
> +#define HW_OCOTP_OPS2 19 /* offset 0x150 */
> +#define HW_OCOTP_OPS3 20 /* offset 0x160 */

Use tabs instead of spaces for indent.

> +
> static u32 chipid;
> static u32 socid;
>
> @@ -379,6 +383,8 @@ static void __init mxs_machine_init(void)
> struct device *parent;
> struct soc_device *soc_dev;
> struct soc_device_attribute *soc_dev_attr;
> + u64 soc_uid = 0;
> + const u32 *ocotp = mxs_get_ocotp();
> int ret;
>
> soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
> @@ -394,8 +400,22 @@ static void __init mxs_machine_init(void)
> soc_dev_attr->soc_id = mxs_get_soc_id();
> soc_dev_attr->revision = mxs_get_revision();
>
> + if (socid == HW_DIGCTL_CHIPID_MX23) {
> + soc_uid = system_serial_low = ocotp[HW_OCOTP_OPS3];
> + } else if (socid == HW_DIGCTL_CHIPID_MX28) {
> + soc_uid = system_serial_high = ocotp[HW_OCOTP_OPS2];
> + soc_uid <<= 32;
> + system_serial_low = ocotp[HW_OCOTP_OPS3];
> + soc_uid |= system_serial_low;
> + }
> +
> + if (soc_uid)
> + soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);
> +
> soc_dev = soc_device_register(soc_dev_attr);
> +

Unnecessary newline.

Shawn

> if (IS_ERR(soc_dev)) {
> + kfree(soc_dev_attr->serial_number);
> kfree(soc_dev_attr->revision);
> kfree(soc_dev_attr);
> return;
> --
> 2.25.1
>