[U-Boot] [PATCH v2 2/4] imx: mx6: add get_cpu_temp_grade to obtain cpu temperature grade from OTP

[Nikolay Dimitrov]

On 05/14/2015 08:11 AM, Tim Harvey wrote:
> The MX6 has a temperature grade defined by OCOTP_MEM0[7:6] which is at 0x480
> in the Fusemap Description Table in the reference manual. Return this value
> as well as min/max temperature based on the value.
>
> Note that the IMX6SDLRM and the IMX6SXRM do not indicate this in the
> their Fusemap Description Table however Freescale has confirmed that these
> eFUSE bits match the description within the IMX6DQRM and that they will
> be added to the next revision of the respective reference manuals.
>
> This has been tested with IMX6 Automative and Industrial parts.
>
> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> ---
> v2:
>   - split out adding get_cpu_temp_grade to its own patch
>   - added note about support of MX6SDL and MX6SX
>
> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> ---
>   arch/arm/cpu/armv7/mx6/soc.c              | 38 +++++++++++++++++++++++++++++++
>   arch/arm/include/asm/arch-mx6/sys_proto.h |  1 +
>   include/imx_thermal.h                     |  6 +++++
>   3 files changed, 45 insertions(+)
>
> diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
> index 71fa1fb..6f501ac 100644
> --- a/arch/arm/cpu/armv7/mx6/soc.c
> +++ b/arch/arm/cpu/armv7/mx6/soc.c
> @@ -124,6 +124,44 @@ u32 get_cpu_speed_grade_hz(void)
>   	return 0;
>   }
>
> +/*
> + * OCOTP_MEM0[7:6] (see Fusemap Description Table offset 0x480)
> + * defines a 2-bit Temperature Grade
> + *
> + * return temperature grade and min/max temperature in celcius
> + */
> +#define OCOTP_MEM0_TEMP_SHIFT          6
> +
> +u32 get_cpu_temp_grade(int *minc, int *maxc)
> +{
> +	struct ocotp_regs *ocotp = (struct ocotp_regs *)OCOTP_BASE_ADDR;
> +	struct fuse_bank *bank = &ocotp->bank[1];
> +	struct fuse_bank1_regs *fuse =
> +		(struct fuse_bank1_regs *)bank->fuse_regs;
> +	uint32_t val;
> +
> +	val = readl(&fuse->mem0);
> +	val >>= OCOTP_MEM0_TEMP_SHIFT;
> +	val &= 0x3;
> +
> +	if (minc && maxc) {
> +		if (val == TEMP_AUTOMOTIVE) {
> +			*minc = -40;
> +			*maxc = 125;
> +		} else if (val == TEMP_INDUSTRIAL) {
> +			*minc = -40;
> +			*maxc = 105;
> +		} else if (val == TEMP_EXTCOMMERCIAL) {
> +			*minc = -20;
> +			*maxc = 105;
> +		} else {
> +			*minc = 0;
> +			*maxc = 95;
> +		}
> +	}
> +	return val;
> +}
> +
>   #ifdef CONFIG_REVISION_TAG
>   u32 __weak get_board_rev(void)
>   {
> diff --git a/arch/arm/include/asm/arch-mx6/sys_proto.h b/arch/arm/include/asm/arch-mx6/sys_proto.h
> index a2cd0a9..c583291 100644
> --- a/arch/arm/include/asm/arch-mx6/sys_proto.h
> +++ b/arch/arm/include/asm/arch-mx6/sys_proto.h
> @@ -17,6 +17,7 @@
>   u32 get_nr_cpus(void);
>   u32 get_cpu_rev(void);
>   u32 get_cpu_speed_grade_hz(void);
> +u32 get_cpu_temp_grade(int *minc, int *maxc);
>
>   /* returns MXC_CPU_ value */
>   #define cpu_type(rev) (((rev) >> 12)&0xff)
> diff --git a/include/imx_thermal.h b/include/imx_thermal.h
> index be13652..8ce333c 100644
> --- a/include/imx_thermal.h
> +++ b/include/imx_thermal.h
> @@ -8,6 +8,12 @@
>   #ifndef _IMX_THERMAL_H_
>   #define _IMX_THERMAL_H_
>
> +/* CPU Temperature Grades */
> +#define TEMP_COMMERCIAL         0
> +#define TEMP_EXTCOMMERCIAL      1
> +#define TEMP_INDUSTRIAL         2
> +#define TEMP_AUTOMOTIVE         3
> +
>   struct imx_thermal_plat {
>   	void *regs;
>   	int fuse_bank;
>

Tested-by: Nikolay Dimitrov <picmaster at mail.bg>

Regards,
Nikolay