2015-05-15 15:20 GMT+02:00 Stefano Babic sbabic@denx.de:
Hi Christian,
On 15/05/2015 09:53, Christian Gmeiner wrote:
Hi
2015-05-14 7:08 GMT+02:00 Tim Harvey tharvey@gateworks.com:
The IMX6 has four different speed grades determined by eFUSE SPEED_GRADING indicated by OCOTP_CFG3[17:16] which is at 0x440 in the Fusemap Description Table. Return this frequency so that it can be used elsewhere.
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.
These have been tested with IMX6 Quad/Solo/Dual-light 800Mhz and 1GHz grades.
Signed-off-by: Tim Harvey tharvey@gateworks.com
arch/arm/cpu/armv7/mx6/soc.c | 41 +++++++++++++++++++++++++++++++ arch/arm/include/asm/arch-mx6/sys_proto.h | 1 + 2 files changed, 42 insertions(+)
diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c index dd34138..71fa1fb 100644 --- a/arch/arm/cpu/armv7/mx6/soc.c +++ b/arch/arm/cpu/armv7/mx6/soc.c @@ -83,6 +83,47 @@ u32 get_cpu_rev(void) return (type << 12) | (reg + 0x10); }
+/*
- OCOTP_CFG3[17:16] (see Fusemap Description Table offset 0x440)
- defines a 2-bit SPEED_GRADING
- */
+#define OCOTP_CFG3_SPEED_SHIFT 16 +#define OCOTP_CFG3_SPEED_800MHZ 0 +#define OCOTP_CFG3_SPEED_850MHZ 1 +#define OCOTP_CFG3_SPEED_1GHZ 2 +#define OCOTP_CFG3_SPEED_1P2GHZ 3
Note: 0x3 is defined as reserved (IMX6DQRM Rev 2, 06/2014).
That means that the manual is buggy, if the SOC returns exactly this value ;-)
yep :)
+u32 get_cpu_speed_grade_hz(void) +{
struct ocotp_regs *ocotp = (struct ocotp_regs *)OCOTP_BASE_ADDR;struct fuse_bank *bank = &ocotp->bank[0];struct fuse_bank0_regs *fuse =(struct fuse_bank0_regs *)bank->fuse_regs;uint32_t val;val = readl(&fuse->cfg3);val >>= OCOTP_CFG3_SPEED_SHIFT;val &= 0x3;switch (val) {/* Valid for IMX6DQ */case OCOTP_CFG3_SPEED_1P2GHZ:if (is_cpu_type(MXC_CPU_MX6Q) || is_cpu_type(MXC_CPU_MX6D))return 1200000000;/* Valid for IMX6SX/IMX6SDL/IMX6DQ */case OCOTP_CFG3_SPEED_1GHZ:return 996000000;/* Valid for IMX6DQ */case OCOTP_CFG3_SPEED_850MHZ:if (is_cpu_type(MXC_CPU_MX6Q) || is_cpu_type(MXC_CPU_MX6D))return 852000000;/* Valid for IMX6SX/IMX6SDL/IMX6DQ */case OCOTP_CFG3_SPEED_800MHZ:return 792000000;}return 0;Do we really need the ifs inside the cases? The speed grading fuse value is read only and we must simply life with the value we read back. So I would drop the is_cpu_type(..) thing.
Function does not returns the value of the fuse, else it should returns val. The value is parsed for consistency, and if it is not, 0 means a failure. IMHO this interpretation is correct - I would agree with you only if the return value would be the read value, but it is not.
If all mx6 variants use the same otp register/values, then the ifs are _NOT_ needed. I hope that later testings/doc updates/etc proofs it and we can get rid of the superfluous ifs.
If they are different then I can life with it.
greets -- Christian Gmeiner, MSc