Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v2 2/2] clk: hi6220: initialize UART1 clock to 150MHz | From | Jorge Ramirez <> | Date | Thu, 7 Jul 2016 08:31:22 +0200 |
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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).
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