Fix calculation of I2C clock for some 86xx chips
PATCH 1/1 Fix calculation of I2C clock for some 86xx chips
Some 86xx chips use CCB as the base clock for the I2C, and others used CCB/2. There is no pattern that can be used to determine which chips use which frequency, so the only way to determine is to look up the actual SOC designation and use the right value for that SOC.
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Yes, this is ugly and stupid, but the only alternative is to update each board configuration file with another CONFIG_ option. And yes, this does mean that as new 86xx variants are announced, cpu/mpc86xx/speed.c may need to be updated.
cpu/mpc86xx/speed.c | 14 +++++++++++++- 1 files changed, 13 insertions(+), 1 deletions(-)
cpu/mpc86xx/speed.c +13 -1
@@ -105,8 +105,20 @@ int get_clocks(void)get_sys_info (&sys_info); gd->cpu_clk = sys_info.freqProcessor; gd->bus_clk = sys_info.freqSystemBus; + +/* +* The base clock for I2C depends on the actual SOC. Unfortunately, +* there is no pattern that can be used to determine the frequency, so +* the only choice is to look up the actual SOC number and use the value +* for that SOC. This information is taken from application note +* AN2919. +*/ +#ifdef CONFIG_MPC8610 gd->i2c1_clk = sys_info.freqSystemBus; - gd->i2c2_clk = sys_info.freqSystemBus; +#else + gd->i2c1_clk = sys_info.freqSystemBus /2 ; +#endif + gd->i2c2_clk = gd->i2c1_clk;if (gd->cpu_clk !=0 )return 0 ;
Signature · 1 line
1.5.4
PATCH 1/1 Fix calculation of I2C clock for some 86xx chips
Quoted 6 lines · In message <[email protected]> you wrote:
Some 86xx chips use CCB as the base clock for the I2C, and others used CCB/2. There is no pattern that can be used to determine which chips use which frequency, so the only way to determine is to look up the actual SOC designation and use the right value for that SOC.
Signed-off-by Timur Tabi <[email protected]>
Will this goin through the 86xx custodian repo, or should I pull this directly?
Best regards,
Wolfgang Denk
Signature · 5 lines
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de "In the long run, every program becomes rococo, and then rubble." - Alan Perlis
PATCH 1/1 Fix calculation of I2C clock for some 86xx chips
Quoted 6 lines · Wolfgang Denk
Quoted 5 lines · In message <[email protected]> you wrote:
Some 86xx chips use CCB as the base clock for the I2C, and others used CCB/2. There is no pattern that can be used to determine which chips use which frequency, so the only way to determine is to look up the actual SOC designation and use the right value for that SOC.
Quoted 9 lines
Quoted 1 line
Signed-off-by Timur Tabi <[email protected]>Will this goin through the 86xx custodian repo, or should I pull this directly?
Best regards,
Wolfgang Denk
Please pick this up directly.
Thanks,
jdl
PATCH 1/1 Fix calculation of I2C clock for some 86xx chips
Wolfgang, I think you forgot this one.
Quoted 23 lines · Jon Loeliger
Quoted 6 lines · Wolfgang Denk
Quoted 5 lines · In message <[email protected]> you wrote:
Some 86xx chips use CCB as the base clock for the I2C, and others used CCB/2. There is no pattern that can be used to determine which chips use which frequency, so the only way to determine is to look up the actual SOC designation and use the right value for that SOC.
Quoted 8 lines
Quoted 1 line
Signed-off-by Timur Tabi <[email protected]>Will this goin through the 86xx custodian repo, or should I pull this directly?
Best regards,
Wolfgang Denk
Please pick this up directly.
Thanks,
jdl
Signature · 2 lines
Timur Tabi Linux kernel developer at Freescale
PATCH 1/1 Fix calculation of I2C clock for some 86xx chips
Quoted 1 line · In message <[email protected]> you wrote:
Wolfgang, I think you forgot this one.
Indeed. I missed that there were actually two very similar messages.
Thanks for pointing out.
Best regards,
Wolfgang Denk
Signature · 4 lines
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de "Don't think; let the machine do it for you!" - E. C. Berkeley
Wolfgang Denk
AppliedPATCH 1/1 Fix calculation of I2C clock for some 86xx chips
In reply to Timur TabiQuoted 8 lines · In message <[email protected]> you wrote:
Some 86xx chips use CCB as the base clock for the I2C, and others used CCB/2. There is no pattern that can be used to determine which chips use which frequency, so the only way to determine is to look up the actual SOC designation and use the right value for that SOC.
Signed-off-by Timur Tabi <[email protected]>---
Quoted 7 lines
Yes, this is ugly and stupid, but the only alternative is to update each board configuration file with another
CONFIG_option. And yes, this does mean that as new 86xx variants are announced,cpu/mpc86xx/speed.cmay need to be updated.cpu/mpc86xx/speed.c | 14 +++++++++++++- 1 files changed, 13 insertions(+), 1 deletions(-)
Applied, thanks.
Best regards,
Wolfgang Denk
Signature · 5 lines
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de An expert is a person who avoids the small errors while sweeping on to the grand fallacy.