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>

1 files changed, 74 insertions, 11 deletions

diff --git a/arch/arm/mach-omap2/clock34xx.h b/arch/arm/mach-omap2/clock34xx.h
index e433aec4efd..57cc2725b92 100644
--- a/arch/arm/mach-omap2/clock34xx.h
+++ b/arch/arm/mach-omap2/clock34xx.h
@@ -1568,7 +1568,7 @@ static const struct clksel ssi_ssr_clksel[] = {
 	{ .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 @@ static struct clk ssi_ssr_fck = {
 	.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 @@ static struct clk core_l3_ick = {
 	.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 @@ static struct clk ssi_l4_ick = {
 	.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 @@ static struct clk ssi_ick = {
 	.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 @@ static struct clk des1_ick = {
 };
 
 /* 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 @@ static struct clk dss1_alwon_fck = {
 	.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 @@ static struct clk dss2_alwon_fck = {
 	.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 @@ static struct clk dss_ick = {
 	.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 csi2_96m_fck = {
 
 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_120m_fck = {
 
 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_48m_fck = {
 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),