Hi,
On Mon, Jan 10, 2011 at 08:12:15PM +0530, Anand Gadiyar wrote:
> The SMSC 3320 USB PHY on the OMAP4 Pandaboard needs a 19.2 MHz
> reference clock. This clock is provided from the OMAP4's fref_clk3
> pad.
>
> Recent changes to clock44xx_data.c made the clock framework aware
> of the existence of these fref_clk[i] lines. If the option
> CONFIG_OMAP_RESET_CLOCKS is enabled in the kernel, then the
> clock framework will turn these clocks off during bootup.
>
> Explicitly request and keep this clock enabled at init for the
> Pandaboard, so that the PHY receives this clock at all times.
>
> Reported-by: Ming Lei <tom.leiming@xxxxxxxxx>
> Signed-off-by: Anand Gadiyar <gadiyar@xxxxxx>
> Cc: Benoit Cousson <b-cousson@xxxxxx>
> Cc: Paul Walmsley <paul@xxxxxxxxx>
> Cc: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> Tony,
>
> The clock database changes were merged just before Christmas, so
> we did not detect this sooner. Would be nice to get this merged in
> the -rc series, so that we get EHCI and ethernet functional on the Panda.
>
> Ming Lei,
>
> Could you please test this and confirm it fixes the issue for you?
>
> - Anand
>
> arch/arm/mach-omap2/board-omap4panda.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> Index: linux-2.6/arch/arm/mach-omap2/board-omap4panda.c
> ===================================================================
> --- linux-2.6.orig/arch/arm/mach-omap2/board-omap4panda.c
> +++ linux-2.6/arch/arm/mach-omap2/board-omap4panda.c
> @@ -19,6 +19,7 @@
> #include <linux/kernel.h>
> #include <linux/init.h>
> #include <linux/platform_device.h>
> +#include <linux/clk.h>
> #include <linux/io.h>
> #include <linux/leds.h>
> #include <linux/gpio.h>
> @@ -95,7 +96,16 @@ static const struct ehci_hcd_omap_platfo
> static void __init omap4_ehci_init(void)
> {
> int ret;
> + struct clk *phy_ref_clk;
>
> + /* FREF_CLK3 provides the 19.2 MHz reference clock to the PHY */
> + phy_ref_clk = clk_get(NULL, "auxclk3_ck");
> + if (IS_ERR(phy_ref_clk)) {
> + pr_err("Cannot request auxclk3\n");
> + goto error1;
> + }
> + clk_set_rate(phy_ref_clk, 19200000);
> + clk_enable(phy_ref_clk);
shouldn't you be enabling a child of this clock which would be the PHY's
reference clock ? What about PM, are you keeping this clock on forever ?
Wouldn't it be better to, at least, pass down a function pointer to
driver so it uses during probe() (to enable clocks) and suspend/resume
??
--
balbi
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