On 03/01/2014 12:37 AM, Tony Lindgren wrote:

* Christoph Fritz [off-list ref] [140214 06:24]:

quoted

Full device tree support for clock control, especially to set frequencies,
is not yet accomplished. Until then, configure the 24Mhz of sys_clkout2 to
feed an USB-Hub here.

Hmm would like to see Tero's comments on this, I wonder if we should
wait on this to avoid extra churn?

Well, the set I posted that adds default clock parenting / default rate 
support to DT hasn't actually moved forward, so you might want to take 
this in as is now if it should be rushed. The clk-enable part isn't done 
currently by anything anyway. Just wondering though, should you create 
some sort of driver for your usb-hub which would control these clocks?

-Tero

Regards,

Tony

quoted

Signed-off-by: Christoph Fritz <redacted>
---
  arch/arm/mach-omap2/pdata-quirks.c |   37 ++++++++++++++++++++++++++++++++++++
  1 file changed, 37 insertions(+)

diff --git a/arch/arm/mach-omap2/pdata-quirks.c b/arch/arm/mach-omap2/pdata-quirks.c
index 435a823..e36ac3f 100644
--- a/arch/arm/mach-omap2/pdata-quirks.c
+++ b/arch/arm/mach-omap2/pdata-quirks.c

@@ -172,6 +172,43 @@ static void __init am3517_evm_legacy_init(void)

  static void __init omap3_dbb056_legacy_init(void)
  {
+	struct clk *clkout2;
+	struct clk *cm96fck;
+
+	/* Reparent clkout2 to 96M_FCK */
+	pr_info("%s: Late Reparent clkout2 to 96M_FCK\n", __func__);
+	clkout2 = clk_get(NULL, "clkout2_src_ck");
+	if (clkout2 < 0) {
+		pr_err("a83x-quirk: couldn't get clkout2_src_ck\n");
+		return;
+	}
+	cm96fck = clk_get(NULL, "cm_96m_fck");
+	if (cm96fck < 0) {
+		pr_err("a83x-quirk: couldn't get cm_96m_fck\n");
+		return;
+	}
+	if (clk_set_parent(clkout2, cm96fck) < 0) {
+		pr_err("a83x-quirk: couldn't reparent clkout2_src_ck\n");
+		return;
+	}
+
+	/* Set clkout2 to 24MHz for internal usb hub*/
+	pr_info("%s: Set clkout2 to 24MHz for internal usb hub\n", __func__);
+	clkout2 = clk_get(NULL, "sys_clkout2");
+	if (clkout2 < 0) {
+		pr_err("%s: couldn't get sys_clkout2\n", __func__);
+		return;
+	}
+	if (clk_set_rate(clkout2, 24000000) < 0) {
+		pr_err("%s: couldn't set sys_clkout2 rate\n", __func__);
+		return;
+	}
+	if (clk_prepare_enable(clkout2) < 0) {
+		pr_err("%s: couldn't enable sys_clkout2\n", __func__);
+		return;
+	}
+
+	/* Initialize display */
  	omap3_dbb056_display_init_of();
  }
  #endif /* CONFIG_ARCH_OMAP3 */
--

1.7.10.4