Messages in this thread | | | Subject | Re: [PATCH v2 2/2] clk: hi6220: initialize UART1 clock to 150MHz | From | Jorge Ramirez <> | Date | Thu, 7 Jul 2016 10:55:05 +0200 |
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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.
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