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OMAP3 clock: correct module IDLEST bits: SSI; DSS; USBHOST; HSOTGUSB
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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>
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Paul Walmsley authored and paul committed Jul 25, 2009
1 parent 3dc2197 commit 3c82e22
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Showing 2 changed files with 185 additions and 18 deletions.
118 changes: 111 additions & 7 deletions arch/arm/mach-omap2/clock34xx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@
* OMAP3-specific clock framework functions
*
* Copyright (C) 2007-2008 Texas Instruments, Inc.
* Copyright (C) 2007-2008 Nokia Corporation
* Copyright (C) 2007-2009 Nokia Corporation
*
* Written by Paul Walmsley
* Testing and integration fixes by Jouni Högander
Expand Down Expand Up @@ -41,6 +41,37 @@

static const struct clkops clkops_noncore_dpll_ops;

static void omap3430es2_clk_ssi_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit);
static void omap3430es2_clk_hsotgusb_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit);
static void omap3430es2_clk_dss_usbhost_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit);

static const struct clkops clkops_omap3430es2_ssi_wait = {
.enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
.find_idlest = omap3430es2_clk_ssi_find_idlest,
.find_companion = omap2_clk_dflt_find_companion,
};

static const struct clkops clkops_omap3430es2_hsotgusb_wait = {
.enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
.find_idlest = omap3430es2_clk_hsotgusb_find_idlest,
.find_companion = omap2_clk_dflt_find_companion,
};

static const struct clkops clkops_omap3430es2_dss_usbhost_wait = {
.enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
.find_idlest = omap3430es2_clk_dss_usbhost_find_idlest,
.find_companion = omap2_clk_dflt_find_companion,
};

#include "clock34xx.h"

struct omap_clk {
Expand Down Expand Up @@ -157,10 +188,13 @@ static struct omap_clk omap34xx_clks[] = {
CLK(NULL, "fshostusb_fck", &fshostusb_fck, CK_3430ES1),
CLK(NULL, "core_12m_fck", &core_12m_fck, CK_343X),
CLK("omap_hdq.0", "fck", &hdq_fck, CK_343X),
CLK(NULL, "ssi_ssr_fck", &ssi_ssr_fck, CK_343X),
CLK(NULL, "ssi_sst_fck", &ssi_sst_fck, CK_343X),
CLK(NULL, "ssi_ssr_fck", &ssi_ssr_fck_3430es1, CK_3430ES1),
CLK(NULL, "ssi_ssr_fck", &ssi_ssr_fck_3430es2, CK_3430ES2),
CLK(NULL, "ssi_sst_fck", &ssi_sst_fck_3430es1, CK_3430ES1),
CLK(NULL, "ssi_sst_fck", &ssi_sst_fck_3430es2, CK_3430ES2),
CLK(NULL, "core_l3_ick", &core_l3_ick, CK_343X),
CLK("musb_hdrc", "ick", &hsotgusb_ick, CK_343X),
CLK("musb_hdrc", "ick", &hsotgusb_ick_3430es1, CK_3430ES1),
CLK("musb_hdrc", "ick", &hsotgusb_ick_3430es2, CK_3430ES2),
CLK(NULL, "sdrc_ick", &sdrc_ick, CK_343X),
CLK(NULL, "gpmc_fck", &gpmc_fck, CK_343X),
CLK(NULL, "security_l3_ick", &security_l3_ick, CK_343X),
Expand Down Expand Up @@ -193,18 +227,21 @@ static struct omap_clk omap34xx_clks[] = {
CLK(NULL, "mailboxes_ick", &mailboxes_ick, CK_343X),
CLK(NULL, "omapctrl_ick", &omapctrl_ick, CK_343X),
CLK(NULL, "ssi_l4_ick", &ssi_l4_ick, CK_343X),
CLK(NULL, "ssi_ick", &ssi_ick, CK_343X),
CLK(NULL, "ssi_ick", &ssi_ick_3430es1, CK_3430ES1),
CLK(NULL, "ssi_ick", &ssi_ick_3430es2, CK_3430ES2),
CLK(NULL, "usb_l4_ick", &usb_l4_ick, CK_3430ES1),
CLK(NULL, "security_l4_ick2", &security_l4_ick2, CK_343X),
CLK(NULL, "aes1_ick", &aes1_ick, CK_343X),
CLK("omap_rng", "ick", &rng_ick, CK_343X),
CLK(NULL, "sha11_ick", &sha11_ick, CK_343X),
CLK(NULL, "des1_ick", &des1_ick, CK_343X),
CLK("omapfb", "dss1_fck", &dss1_alwon_fck, CK_343X),
CLK("omapfb", "dss1_fck", &dss1_alwon_fck_3430es1, CK_3430ES1),
CLK("omapfb", "dss1_fck", &dss1_alwon_fck_3430es2, CK_3430ES2),
CLK("omapfb", "tv_fck", &dss_tv_fck, CK_343X),
CLK("omapfb", "video_fck", &dss_96m_fck, CK_343X),
CLK("omapfb", "dss2_fck", &dss2_alwon_fck, CK_343X),
CLK("omapfb", "ick", &dss_ick, CK_343X),
CLK("omapfb", "ick", &dss_ick_3430es1, CK_3430ES1),
CLK("omapfb", "ick", &dss_ick_3430es2, CK_3430ES2),
CLK(NULL, "cam_mclk", &cam_mclk, CK_343X),
CLK(NULL, "cam_ick", &cam_ick, CK_343X),
CLK(NULL, "csi2_96m_fck", &csi2_96m_fck, CK_343X),
Expand Down Expand Up @@ -300,6 +337,73 @@ static struct omap_clk omap34xx_clks[] = {
*/
#define SDRC_MPURATE_LOOPS 96

/**
* omap3430es2_clk_ssi_find_idlest - return CM_IDLEST info for SSI
* @clk: struct clk * being enabled
* @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
* @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
*
* The OMAP3430ES2 SSI target CM_IDLEST bit is at a different shift
* from the CM_{I,F}CLKEN bit. Pass back the correct info via
* @idlest_reg and @idlest_bit. No return value.
*/
static void omap3430es2_clk_ssi_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit)
{
u32 r;

r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
*idlest_reg = (__force void __iomem *)r;
*idlest_bit = OMAP3430ES2_ST_SSI_IDLE_SHIFT;
}

/**
* omap3430es2_clk_dss_usbhost_find_idlest - CM_IDLEST info for DSS, USBHOST
* @clk: struct clk * being enabled
* @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
* @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
*
* Some OMAP modules on OMAP3 ES2+ chips have both initiator and
* target IDLEST bits. For our purposes, we are concerned with the
* target IDLEST bits, which exist at a different bit position than
* the *CLKEN bit position for these modules (DSS and USBHOST) (The
* default find_idlest code assumes that they are at the same
* position.) No return value.
*/
static void omap3430es2_clk_dss_usbhost_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit)
{
u32 r;

r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
*idlest_reg = (__force void __iomem *)r;
/* USBHOST_IDLE has same shift */
*idlest_bit = OMAP3430ES2_ST_DSS_IDLE_SHIFT;
}

/**
* omap3430es2_clk_hsotgusb_find_idlest - return CM_IDLEST info for HSOTGUSB
* @clk: struct clk * being enabled
* @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
* @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
*
* The OMAP3430ES2 HSOTGUSB target CM_IDLEST bit is at a different
* shift from the CM_{I,F}CLKEN bit. Pass back the correct info via
* @idlest_reg and @idlest_bit. No return value.
*/
static void omap3430es2_clk_hsotgusb_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit)
{
u32 r;

r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
*idlest_reg = (__force void __iomem *)r;
*idlest_bit = OMAP3430ES2_ST_HSOTGUSB_IDLE_SHIFT;
}

/**
* omap3_dpll_recalc - recalculate DPLL rate
* @clk: DPLL struct clk
Expand Down
85 changes: 74 additions & 11 deletions arch/arm/mach-omap2/clock34xx.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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,
};
Expand All @@ -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,
Expand Down Expand Up @@ -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,
Expand All @@ -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 */

Expand Down Expand Up @@ -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,
Expand All @@ -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,
Expand Down Expand Up @@ -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,
Expand All @@ -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 = {
Expand Down Expand Up @@ -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),
Expand All @@ -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),
Expand All @@ -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),
Expand Down

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