[PATCH v2] ARM: OMAP4: hwmod data: make 'ocp2scp_usb_phy_phy_48m" as the main clock

Paul Walmsley
2013-04-10T19:41:41Z

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From: Kishon Vijay Abraham I <kishon@ti.com>

Commit 92702df3570e ("ARM: OMAP4: PM: fix PM regression introduced by recent
clock cleanup") makes the 'ocp2scp_usb_phy_phy_48m' as optional
functional clock causing regression in MUSB. But this 48MHz clock is a
mandatory clock for usb phy attached to ocp2scp and hence made as the main
clock for ocp2scp.

Cc: Keerthy <j-keerthy@ti.com>
Cc: Benoît Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
[paul@pwsan.com: add comment to the hwmod data to try to prevent any
future mistakes here]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
---

Nothing further received from Kishon per the request:

http://marc.info/?l=linux-omap&m=136554118302342&w=2

Since the deadline for v3.9-rc fixes is quite close, have added the
comment myself, and have confirmed that this patch does not cause
additional PM regressions on 4460 Panda-ES in the tests here.

arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
index 9e05765..eaba9dc 100644
--- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
@@ -2714,16 +2714,22 @@ static struct omap_ocp2scp_dev ocp2scp_dev_attr[] = {
{ }
};

-static struct omap_hwmod_opt_clk ocp2scp_usb_phy_opt_clks[] = {
- { .role = "48mhz", .clk = "ocp2scp_usb_phy_phy_48m" },
-};
-
/* ocp2scp_usb_phy */
static struct omap_hwmod omap44xx_ocp2scp_usb_phy_hwmod = {
.name = "ocp2scp_usb_phy",
.class = &omap44xx_ocp2scp_hwmod_class,
.clkdm_name = "l3_init_clkdm",
- .main_clk = "func_48m_fclk",
+ /*
+ * ocp2scp_usb_phy_phy_48m is provided by the OMAP4 PRCM IP
+ * block as an "optional clock," and normally should never be
+ * specified as the main_clk for an OMAP IP block. However it
+ * turns out that this clock is actually the main clock for
+ * the ocp2scp_usb_phy IP block:
+ * http://lists.infradead.org/pipermail/linux-arm-kernel/2012-September/119943.html
+ * So listing ocp2scp_usb_phy_phy_48m as a main_clk here seems
+ * to be the best workaround.
+ */
+ .main_clk = "ocp2scp_usb_phy_phy_48m",
.prcm = {
.omap4 = {
.clkctrl_offs = OMAP4_CM_L3INIT_USBPHYOCP2SCP_CLKCTRL_OFFSET,
@@ -2732,8 +2738,6 @@ static struct omap_hwmod omap44xx_ocp2scp_usb_phy_hwmod = {
},
},
.dev_attr = ocp2scp_dev_attr,
- .opt_clks = ocp2scp_usb_phy_opt_clks,
- .opt_clks_cnt = ARRAY_SIZE(ocp2scp_usb_phy_opt_clks),
};

/*
--
1.7.10.4