[U-Boot-Users] [PATCH] 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.
Signed-off-by: Timur Tabi timur@freescale.com ---
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(-)
diff --git a/cpu/mpc86xx/speed.c b/cpu/mpc86xx/speed.c index 7e884f8..da5b58b 100644 --- a/cpu/mpc86xx/speed.c +++ b/cpu/mpc86xx/speed.c @@ -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;

In message 1207325771-1374-1-git-send-email-timur@freescale.com 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 timur@freescale.com
Will this goin through the 86xx custodian repo, or should I pull this directly?
Best regards,
Wolfgang Denk

On Fri, 2008-04-18 at 06:14 +0200, Wolfgang Denk wrote:
In message 1207325771-1374-1-git-send-email-timur@freescale.com 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 timur@freescale.com
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

Wolfgang, I think you forgot this one.
Jon Loeliger wrote:
On Fri, 2008-04-18 at 06:14 +0200, Wolfgang Denk wrote:
In message 1207325771-1374-1-git-send-email-timur@freescale.com 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 timur@freescale.com
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

In message 4818CE68.3040901@freescale.com 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

In message 1207325771-1374-1-git-send-email-timur@freescale.com 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 timur@freescale.com
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(-)
Applied, thanks.
Best regards,
Wolfgang Denk
participants (3)
-
Jon Loeliger
-
Timur Tabi
-
Wolfgang Denk