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Commit 0a384290 authored by Kuninori Morimoto's avatar Kuninori Morimoto Committed by Simon Horman
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ARM: shmobile: r8a7740: add USB24 clock explain 



USBCKCR is controlling USB parent clock and divide rate.
This parent clock is used as a "usb24s" from other devices,
but the "divide rate" is not used.
Further, this clock itself is known as "usb24".
So, to set this clock is a little confusable.
This patch adds quick explain and sample settings for this clock.

Signed-off-by: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
parent 167443b1

arch/arm/mach-shmobile/clock-r8a7740.c

+16 −0
Original line number Diff line number Diff line
@@ -188,6 +188,22 @@ static struct clk pllc1_div2_clk = { 
};



/* USB clock */

/*

 * USBCKCR is controlling usb24 clock

 * bit[7] : parent clock

 * bit[6] : clock divide rate

 * And this bit[7] is used as a "usb24s" from other devices.

 * (Video clock / Sub clock / SPU clock)

 * You can controll this clock as a below.

 *

 * struct clk *usb24	= clk_get(dev,  "usb24");

 * struct clk *usb24s	= clk_get(NULL, "usb24s");

 * struct clk *system	= clk_get(NULL, "system_clk");

 * int rate = clk_get_rate(system);

 *

 * clk_set_parent(usb24s, system);  // for bit[7]

 * clk_set_rate(usb24, rate / 2);   // for bit[6]

 */

static struct clk *usb24s_parents[] = {

	[0] = &system_clk,

	[1] = &extal2_clk