Re: [PATCH 2/2] clk: hi6220: initialize UART1 clock to 150MHz

From: Jorge Ramirez
Date: Tue Jun 28 2016 - 07:58:00 EST


On 06/28/2016 12:31 PM, Guodong Xu wrote:
From: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@xxxxxxxxxx>

Early at boot, during the sys_clk initialization, make sure UART1 uses
the higher frequency clock.

This enables support for higher baud rates (up to 3Mbps) required to
support faster bluetooth transfers.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@xxxxxxxxxx>
Signed-off-by: Guodong Xu <guodong.xu@xxxxxxxxxx>
---
drivers/clk/hisilicon/clk-hi6220.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/hisilicon/clk-hi6220.c b/drivers/clk/hisilicon/clk-hi6220.c
index a36ffcb..55bd9bb 100644
--- a/drivers/clk/hisilicon/clk-hi6220.c
+++ b/drivers/clk/hisilicon/clk-hi6220.c
@@ -11,6 +11,7 @@
*/
#include <linux/kernel.h>
+#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/io.h>
@@ -70,10 +71,10 @@ static struct hisi_gate_clock hi6220_separated_gate_clks_ao[] __initdata = {
{ HI6220_UART0_PCLK, "uart0_pclk", "clk_tcxo", CLK_SET_RATE_PARENT|CLK_IGNORE_UNUSED, 0x630, 24, 0, },
};
+static struct hisi_clock_data *clk_data_ao;
+
static void __init hi6220_clk_ao_init(struct device_node *np)
{
- struct hisi_clock_data *clk_data_ao;
-
clk_data_ao = hisi_clk_init(np, HI6220_AO_NR_CLKS);
if (!clk_data_ao)
return;
@@ -192,6 +193,13 @@ 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_data_ao)
+ return;
+
+ /* enable high speed clock on UART1 mux */
+ clk_set_parent(clk_data->clk_data.clks[HI6220_UART1_SRC],
+ clk_data_ao->clk_data.clks[HI6220_150M]);
}
CLK_OF_DECLARE(hi6220_clk_sys, "hisilicon,hi6220-sysctrl", hi6220_clk_sys_init);

please bear with me on this. it does need rework.