| Message ID | 1467189955-21694-2-git-send-email-guodong.xu@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 07/06/2016 11:43 PM, Michael Turquette wrote: > Quoting Guodong Xu (2016-06-29 01:45:55) >> >From: Jorge Ramirez-Ortiz<jorge.ramirez-ortiz@linaro.org> >> > >> >Early at boot, during the sys_clk initialization, make sure UART1 uses >> >the higher frequency clock, 150MHz. >> > >> >This enables support for higher baud rates (up to 3Mbps) in UART1, which >> >is required by faster bluetooth transfers. >> > >> >v2: use clk_set_rate() to propergate clock settings. >> > >> >Signed-off-by: Jorge Ramirez-Ortiz<jorge.ramirez-ortiz@linaro.org> >> >Signed-off-by: Guodong Xu<guodong.xu@linaro.org> >> >--- >> > drivers/clk/hisilicon/clk-hi6220.c | 4 ++++ >> > 1 file changed, 4 insertions(+) >> > >> >diff --git a/drivers/clk/hisilicon/clk-hi6220.c b/drivers/clk/hisilicon/clk-hi6220.c >> >index a36ffcb..631c56f 100644 >> >--- a/drivers/clk/hisilicon/clk-hi6220.c >> >+++ b/drivers/clk/hisilicon/clk-hi6220.c >> >@@ -12,6 +12,7 @@ >> > >> > #include <linux/kernel.h> >> > #include <linux/clk-provider.h> >> >+#include <linux/clk.h> >> > #include <linux/clkdev.h> >> > #include <linux/io.h> >> > #include <linux/of.h> >> >@@ -192,6 +193,9 @@ static void __init hi6220_clk_sys_init(struct device_node *np) >> > >> > hi6220_clk_register_divider(hi6220_div_clks_sys, >> > ARRAY_SIZE(hi6220_div_clks_sys), clk_data); >> >+ >> >+ if (clk_set_rate(clk_data->clk_data.clks[HI6220_UART1_SRC], 150000000)) >> >+ pr_err("failed to set uart1 clock rate\n"); > Why doesn't the UART driver call clk_get and then clk_set_rate on this > clock? Why do it in the clk provider driver? yes that was my initial choice as well; in the end I opted to do it in the clock driver because of it being a value that will not have to ever change for the SoC and - maybe more importantly- because of not having a DT property available for the primecell pl011 uart where to specify the value (so I thought this was a less intrusive implementation).
On 07/07/2016 08:31 AM, Jorge Ramirez wrote: > On 07/06/2016 11:43 PM, Michael Turquette wrote: >> Quoting Guodong Xu (2016-06-29 01:45:55) >>> >From: Jorge Ramirez-Ortiz<jorge.ramirez-ortiz@linaro.org> >>> > >>> >Early at boot, during the sys_clk initialization, make sure UART1 uses >>> >the higher frequency clock, 150MHz. >>> > >>> >This enables support for higher baud rates (up to 3Mbps) in UART1, >>> which >>> >is required by faster bluetooth transfers. >>> > >>> >v2: use clk_set_rate() to propergate clock settings. >>> > >>> >Signed-off-by: Jorge Ramirez-Ortiz<jorge.ramirez-ortiz@linaro.org> >>> >Signed-off-by: Guodong Xu<guodong.xu@linaro.org> >>> >--- >>> > drivers/clk/hisilicon/clk-hi6220.c | 4 ++++ >>> > 1 file changed, 4 insertions(+) >>> > >>> >diff --git a/drivers/clk/hisilicon/clk-hi6220.c >>> b/drivers/clk/hisilicon/clk-hi6220.c >>> >index a36ffcb..631c56f 100644 >>> >--- a/drivers/clk/hisilicon/clk-hi6220.c >>> >+++ b/drivers/clk/hisilicon/clk-hi6220.c >>> >@@ -12,6 +12,7 @@ >>> > > #include <linux/kernel.h> >>> > #include <linux/clk-provider.h> >>> >+#include <linux/clk.h> >>> > #include <linux/clkdev.h> >>> > #include <linux/io.h> >>> > #include <linux/of.h> >>> >@@ -192,6 +193,9 @@ static void __init hi6220_clk_sys_init(struct >>> device_node *np) >>> > > hi6220_clk_register_divider(hi6220_div_clks_sys, >>> > ARRAY_SIZE(hi6220_div_clks_sys), clk_data); >>> >+ >>> >+ if (clk_set_rate(clk_data->clk_data.clks[HI6220_UART1_SRC], >>> 150000000)) >>> >+ pr_err("failed to set uart1 clock rate\n"); >> Why doesn't the UART driver call clk_get and then clk_set_rate on this >> clock? Why do it in the clk provider driver? > > yes that was my initial choice as well; in the end I opted to do it in > the clock driver because of it being a value that will not have to > ever change for the SoC and - maybe more importantly- because of not > having a DT property available for the primecell pl011 uart where to > specify the value (so I thought this was a less intrusive > implementation). > > I have v3 ready (changes done in amba-pl011.c and devicetree/bindings) please let me know if I should send those instead.
On 07/08/2016 03:48 AM, Michael Turquette wrote: > Quoting Jorge Ramirez (2016-07-07 01:55:05) >> On 07/07/2016 08:31 AM, Jorge Ramirez wrote: >>> On 07/06/2016 11:43 PM, Michael Turquette wrote: >>>> Quoting Guodong Xu (2016-06-29 01:45:55) >>>>>> From: Jorge Ramirez-Ortiz<jorge.ramirez-ortiz@linaro.org> >>>>>> >>>>>> Early at boot, during the sys_clk initialization, make sure UART1 uses >>>>>> the higher frequency clock, 150MHz. >>>>>> >>>>>> This enables support for higher baud rates (up to 3Mbps) in UART1, >>>>> which >>>>>> is required by faster bluetooth transfers. >>>>>> >>>>>> v2: use clk_set_rate() to propergate clock settings. >>>>>> >>>>>> Signed-off-by: Jorge Ramirez-Ortiz<jorge.ramirez-ortiz@linaro.org> >>>>>> Signed-off-by: Guodong Xu<guodong.xu@linaro.org> >>>>>> --- >>>>>> drivers/clk/hisilicon/clk-hi6220.c | 4 ++++ >>>>>> 1 file changed, 4 insertions(+) >>>>>> >>>>>> diff --git a/drivers/clk/hisilicon/clk-hi6220.c >>>>> b/drivers/clk/hisilicon/clk-hi6220.c >>>>>> index a36ffcb..631c56f 100644 >>>>>> --- a/drivers/clk/hisilicon/clk-hi6220.c >>>>>> +++ b/drivers/clk/hisilicon/clk-hi6220.c >>>>>> @@ -12,6 +12,7 @@ >>>>>> > #include <linux/kernel.h> >>>>>> #include <linux/clk-provider.h> >>>>>> +#include <linux/clk.h> >>>>>> #include <linux/clkdev.h> >>>>>> #include <linux/io.h> >>>>>> #include <linux/of.h> >>>>>> @@ -192,6 +193,9 @@ static void __init hi6220_clk_sys_init(struct >>>>> device_node *np) >>>>>> > hi6220_clk_register_divider(hi6220_div_clks_sys, >>>>>> ARRAY_SIZE(hi6220_div_clks_sys), clk_data); >>>>>> + >>>>>> + if (clk_set_rate(clk_data->clk_data.clks[HI6220_UART1_SRC], >>>>> 150000000)) >>>>>> + pr_err("failed to set uart1 clock rate\n"); >>>> Why doesn't the UART driver call clk_get and then clk_set_rate on this >>>> clock? Why do it in the clk provider driver? >>> yes that was my initial choice as well; in the end I opted to do it in >>> the clock driver because of it being a value that will not have to >>> ever change for the SoC and - maybe more importantly- because of not >>> having a DT property available for the primecell pl011 uart where to >>> specify the value (so I thought this was a less intrusive >>> implementation). >>> >>> >> I have v3 ready (changes done in amba-pl011.c and devicetree/bindings) >> please let me know if I should send those instead. > Yes, please do. Are you using the clock-assigned-rates property? oops (was using clock-frequency), yes it is now. thanks will send it shortly.
diff --git a/drivers/clk/hisilicon/clk-hi6220.c b/drivers/clk/hisilicon/clk-hi6220.c index a36ffcb..631c56f 100644 --- a/drivers/clk/hisilicon/clk-hi6220.c +++ b/drivers/clk/hisilicon/clk-hi6220.c @@ -12,6 +12,7 @@ #include <linux/kernel.h> #include <linux/clk-provider.h> +#include <linux/clk.h> #include <linux/clkdev.h> #include <linux/io.h> #include <linux/of.h> @@ -192,6 +193,9 @@ static void __init hi6220_clk_sys_init(struct device_node *np) hi6220_clk_register_divider(hi6220_div_clks_sys, ARRAY_SIZE(hi6220_div_clks_sys), clk_data); + + if (clk_set_rate(clk_data->clk_data.clks[HI6220_UART1_SRC], 150000000)) + pr_err("failed to set uart1 clock rate\n"); } CLK_OF_DECLARE(hi6220_clk_sys, "hisilicon,hi6220-sysctrl", hi6220_clk_sys_init);