OMAP3 clock: correct module IDLEST bits: SSI; DSS; USBHOST; HSOTGUSB
Fix two bugs in the OMAP3 clock tree pertaining to the SSI, DSS,
USBHOST, and HSOTGUSB devices. These devices are both interconnect
initiators and targets. Without this patch, clk_enable()s on clocks for
these modules can be very high latency (potentially up to ~200
milliseconds) and message such as the following are generated:
Clock usbhost_48m_fck didn't enable in 100000 tries
Two bugs are fixed by this patch. First, OMAP hardware only supports
target CM_IDLEST register bits on ES2+ chips and beyond. ES1 chips
should not wait for these clocks to enable. So, split the appropriate
clocks into ES1 and ES2+ variants, so that kernels running on ES1
devices won't try to wait.
Second, the current heuristic in omap2_clk_dflt_find_idlest() will
fail for these clocks. It assumes that the CM_IDLEST bit to wait upon
is the same as the CM_*CLKEN bit, which is false[1]. Fix by
implementing custom clkops .find_idlest function pointers for the
appropriate clocks that return the correct slave IDLEST bit shift.
This was originally fixed in the linux-omap kernel during 2.6.29 in a
slightly different manner[2][3].
In the medium-term future, all of the module IDLEST code will
eventually be moved to the omap_hwmod code.
Problem reported by Jarkko Nikula <jhnikula@gmail.com>:
http://marc.info/?l=linux-omap&m=124306184903679&w=2
...
1. See for example 34xx TRM Revision P Table 4-213 and 4-217 (for the
DSS case).
2. http://www.spinics.net/lists/linux-omap/msg05512.html et seq.
3. http://lkml.indiana.edu/hypermail/linux/kernel/0901.3/01498.html
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Jarkko Nikula <jhnikula@gmail.com>
diff --git a/arch/arm/mach-omap2/clock34xx.h b/arch/arm/mach-omap2/clock34xx.h
index e433aec..57cc272 100644
--- a/arch/arm/mach-omap2/clock34xx.h
+++ b/arch/arm/mach-omap2/clock34xx.h
@@ -1568,7 +1568,7 @@
{ .parent = NULL }
};
-static struct clk ssi_ssr_fck = {
+static struct clk ssi_ssr_fck_3430es1 = {
.name = "ssi_ssr_fck",
.ops = &clkops_omap2_dflt,
.init = &omap2_init_clksel_parent,
@@ -1581,10 +1581,31 @@
.recalc = &omap2_clksel_recalc,
};
-static struct clk ssi_sst_fck = {
+static struct clk ssi_ssr_fck_3430es2 = {
+ .name = "ssi_ssr_fck",
+ .ops = &clkops_omap3430es2_ssi_wait,
+ .init = &omap2_init_clksel_parent,
+ .enable_reg = OMAP_CM_REGADDR(CORE_MOD, CM_FCLKEN1),
+ .enable_bit = OMAP3430_EN_SSI_SHIFT,
+ .clksel_reg = OMAP_CM_REGADDR(CORE_MOD, CM_CLKSEL),
+ .clksel_mask = OMAP3430_CLKSEL_SSI_MASK,
+ .clksel = ssi_ssr_clksel,
+ .clkdm_name = "core_l4_clkdm",
+ .recalc = &omap2_clksel_recalc,
+};
+
+static struct clk ssi_sst_fck_3430es1 = {
.name = "ssi_sst_fck",
.ops = &clkops_null,
- .parent = &ssi_ssr_fck,
+ .parent = &ssi_ssr_fck_3430es1,
+ .fixed_div = 2,
+ .recalc = &omap2_fixed_divisor_recalc,
+};
+
+static struct clk ssi_sst_fck_3430es2 = {
+ .name = "ssi_sst_fck",
+ .ops = &clkops_null,
+ .parent = &ssi_ssr_fck_3430es2,
.fixed_div = 2,
.recalc = &omap2_fixed_divisor_recalc,
};
@@ -1606,9 +1627,19 @@
.recalc = &followparent_recalc,
};
-static struct clk hsotgusb_ick = {
+static struct clk hsotgusb_ick_3430es1 = {
.name = "hsotgusb_ick",
- .ops = &clkops_omap2_dflt_wait,
+ .ops = &clkops_omap2_dflt,
+ .parent = &core_l3_ick,
+ .enable_reg = OMAP_CM_REGADDR(CORE_MOD, CM_ICLKEN1),
+ .enable_bit = OMAP3430_EN_HSOTGUSB_SHIFT,
+ .clkdm_name = "core_l3_clkdm",
+ .recalc = &followparent_recalc,
+};
+
+static struct clk hsotgusb_ick_3430es2 = {
+ .name = "hsotgusb_ick",
+ .ops = &clkops_omap3430es2_hsotgusb_wait,
.parent = &core_l3_ick,
.enable_reg = OMAP_CM_REGADDR(CORE_MOD, CM_ICLKEN1),
.enable_bit = OMAP3430_EN_HSOTGUSB_SHIFT,
@@ -1947,7 +1978,7 @@
.recalc = &followparent_recalc,
};
-static struct clk ssi_ick = {
+static struct clk ssi_ick_3430es1 = {
.name = "ssi_ick",
.ops = &clkops_omap2_dflt,
.parent = &ssi_l4_ick,
@@ -1957,6 +1988,16 @@
.recalc = &followparent_recalc,
};
+static struct clk ssi_ick_3430es2 = {
+ .name = "ssi_ick",
+ .ops = &clkops_omap3430es2_ssi_wait,
+ .parent = &ssi_l4_ick,
+ .enable_reg = OMAP_CM_REGADDR(CORE_MOD, CM_ICLKEN1),
+ .enable_bit = OMAP3430_EN_SSI_SHIFT,
+ .clkdm_name = "core_l4_clkdm",
+ .recalc = &followparent_recalc,
+};
+
/* REVISIT: Technically the TRM claims that this is CORE_CLK based,
* but l4_ick makes more sense to me */
@@ -2024,7 +2065,7 @@
};
/* DSS */
-static struct clk dss1_alwon_fck = {
+static struct clk dss1_alwon_fck_3430es1 = {
.name = "dss1_alwon_fck",
.ops = &clkops_omap2_dflt,
.parent = &dpll4_m4x2_ck,
@@ -2034,6 +2075,16 @@
.recalc = &followparent_recalc,
};
+static struct clk dss1_alwon_fck_3430es2 = {
+ .name = "dss1_alwon_fck",
+ .ops = &clkops_omap3430es2_dss_usbhost_wait,
+ .parent = &dpll4_m4x2_ck,
+ .enable_reg = OMAP_CM_REGADDR(OMAP3430_DSS_MOD, CM_FCLKEN),
+ .enable_bit = OMAP3430_EN_DSS1_SHIFT,
+ .clkdm_name = "dss_clkdm",
+ .recalc = &followparent_recalc,
+};
+
static struct clk dss_tv_fck = {
.name = "dss_tv_fck",
.ops = &clkops_omap2_dflt,
@@ -2067,7 +2118,7 @@
.recalc = &followparent_recalc,
};
-static struct clk dss_ick = {
+static struct clk dss_ick_3430es1 = {
/* Handles both L3 and L4 clocks */
.name = "dss_ick",
.ops = &clkops_omap2_dflt,
@@ -2079,6 +2130,18 @@
.recalc = &followparent_recalc,
};
+static struct clk dss_ick_3430es2 = {
+ /* Handles both L3 and L4 clocks */
+ .name = "dss_ick",
+ .ops = &clkops_omap3430es2_dss_usbhost_wait,
+ .parent = &l4_ick,
+ .init = &omap2_init_clk_clkdm,
+ .enable_reg = OMAP_CM_REGADDR(OMAP3430_DSS_MOD, CM_ICLKEN),
+ .enable_bit = OMAP3430_CM_ICLKEN_DSS_EN_DSS_SHIFT,
+ .clkdm_name = "dss_clkdm",
+ .recalc = &followparent_recalc,
+};
+
/* CAM */
static struct clk cam_mclk = {
@@ -2118,7 +2181,7 @@
static struct clk usbhost_120m_fck = {
.name = "usbhost_120m_fck",
- .ops = &clkops_omap2_dflt_wait,
+ .ops = &clkops_omap2_dflt,
.parent = &dpll5_m2_ck,
.init = &omap2_init_clk_clkdm,
.enable_reg = OMAP_CM_REGADDR(OMAP3430ES2_USBHOST_MOD, CM_FCLKEN),
@@ -2129,7 +2192,7 @@
static struct clk usbhost_48m_fck = {
.name = "usbhost_48m_fck",
- .ops = &clkops_omap2_dflt_wait,
+ .ops = &clkops_omap3430es2_dss_usbhost_wait,
.parent = &omap_48m_fck,
.init = &omap2_init_clk_clkdm,
.enable_reg = OMAP_CM_REGADDR(OMAP3430ES2_USBHOST_MOD, CM_FCLKEN),
@@ -2141,7 +2204,7 @@
static struct clk usbhost_ick = {
/* Handles both L3 and L4 clocks */
.name = "usbhost_ick",
- .ops = &clkops_omap2_dflt_wait,
+ .ops = &clkops_omap3430es2_dss_usbhost_wait,
.parent = &l4_ick,
.init = &omap2_init_clk_clkdm,
.enable_reg = OMAP_CM_REGADDR(OMAP3430ES2_USBHOST_MOD, CM_ICLKEN),