[PATCH] ARM: OMAP3: PM: fix I/O wakeup and I/O chain clock control detection
Paul Walmsley
paul at pwsan.com
Thu Oct 6 15:11:38 EDT 2011
The way that we detect which OMAP3 chips support I/O wakeup and
software I/O chain clock control is broken.
Currently, I/O wakeup is marked as present for all OMAP3 SoCs other
than the AM3505/3517. The TI81xx family of SoCs are at present
considered to be OMAP3 SoCs, but don't support I/O wakeup. To resolve
this, convert the existing blacklist approach to an explicit,
whitelist support, in which only SoCs which are known to support I/O
wakeup are listed. (At present, this only includes OMAP34xx,
OMAP3503, OMAP3515, OMAP3525, OMAP3530, and OMAP36xx.)
Also, the current code incorrectly detects the presence of a
software-controllable I/O chain clock on several chips that don't
support it. This results in writes to reserved bitfields, unnecessary
delays, and console messages on kernels running on those chips:
http://www.spinics.net/lists/linux-omap/msg58735.html
Convert this test to a feature test with a chip-by-chip whitelist.
Thanks to Dave Hylands <dhylands at gmail.com> for reporting this problem
and doing some testing to help isolate the cause.
Signed-off-by: Paul Walmsley <paul at pwsan.com>
Cc: Kevin Hilman <khilman at ti.com>
Cc: Dave Hylands <dhylands at gmail.com>
Cc: Steve Sakoman <sakoman at gmail.com>
---
arch/arm/mach-omap2/id.c | 6 +++-
arch/arm/mach-omap2/pm34xx.c | 44 +++++++++++++++++---------------
arch/arm/plat-omap/include/plat/cpu.h | 17 +++++++++---
3 files changed, 40 insertions(+), 27 deletions(-)
diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
index 37efb86..eb1b8e4 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -201,8 +201,12 @@ static void __init omap3_check_features(void)
OMAP3_CHECK_FEATURE(status, ISP);
if (cpu_is_omap3630())
omap_features |= OMAP3_HAS_192MHZ_CLK;
- if (!cpu_is_omap3505() && !cpu_is_omap3517())
+ if (cpu_is_omap3430() || cpu_is_omap3630())
omap_features |= OMAP3_HAS_IO_WAKEUP;
+ if ((omap_rev() == OMAP3430_REV_ES3_1 &&
+ omap_rev() == OMAP3430_REV_ES3_1_2) ||
+ cpu_is_omap3630())
+ omap_features |= OMAP3_HAS_IO_CHAIN_CTRL;
omap_features |= OMAP3_HAS_SDRC;
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 7255d9b..a6156bd 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -99,31 +99,28 @@ static void omap3_enable_io_chain(void)
{
int timeout = 0;
- if (omap_rev() >= OMAP3430_REV_ES3_1) {
- omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
- PM_WKEN);
- /* Do a readback to assure write has been done */
- omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
-
- while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN) &
- OMAP3430_ST_IO_CHAIN_MASK)) {
- timeout++;
- if (timeout > 1000) {
- printk(KERN_ERR "Wake up daisy chain "
- "activation failed.\n");
- return;
- }
- omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK,
- WKUP_MOD, PM_WKEN);
+ omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+ PM_WKEN);
+ /* Do a readback to assure write has been done */
+ omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
+
+ while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN) &
+ OMAP3430_ST_IO_CHAIN_MASK)) {
+ timeout++;
+ if (timeout > 1000) {
+ printk(KERN_ERR "Wake up daisy chain "
+ "activation failed.\n");
+ return;
}
+ omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK,
+ WKUP_MOD, PM_WKEN);
}
}
static void omap3_disable_io_chain(void)
{
- if (omap_rev() >= OMAP3430_REV_ES3_1)
- omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
- PM_WKEN);
+ omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+ PM_WKEN);
}
static void omap3_core_save_context(void)
@@ -376,7 +373,8 @@ void omap_sram_idle(void)
(per_next_state < PWRDM_POWER_ON ||
core_next_state < PWRDM_POWER_ON)) {
omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD, PM_WKEN);
- omap3_enable_io_chain();
+ if (omap3_has_io_chain_ctrl())
+ omap3_enable_io_chain();
}
/* Block console output in case it is on one of the OMAP UARTs */
@@ -475,7 +473,8 @@ console_still_active:
core_next_state < PWRDM_POWER_ON)) {
omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
PM_WKEN);
- omap3_disable_io_chain();
+ if (omap3_has_io_chain_ctrl())
+ omap3_disable_io_chain();
}
pwrdm_post_transition();
@@ -870,6 +869,9 @@ static int __init omap3_pm_init(void)
if (!cpu_is_omap34xx())
return -ENODEV;
+ if (!omap3_has_io_chain_ctrl())
+ pr_warning("PM: no software I/O chain control; some wakeups may be lost\n");
+
pm_errata_configure();
/* XXX prcm_setup_regs needs to be before enabling hw
diff --git a/arch/arm/plat-omap/include/plat/cpu.h b/arch/arm/plat-omap/include/plat/cpu.h
index 67b3d75..3a280aa 100644
--- a/arch/arm/plat-omap/include/plat/cpu.h
+++ b/arch/arm/plat-omap/include/plat/cpu.h
@@ -477,6 +477,13 @@ void omap2_check_revision(void);
/*
* Runtime detection of OMAP3 features
+ *
+ * OMAP3_HAS_IO_CHAIN_CTRL: Some later members of the OMAP3 chip
+ * family have OS-level control over the I/O chain clock. This is
+ * to avoid a window during which wakeups could potentially be lost
+ * during powerdomain transitions. If this bit is set, it
+ * indicates that the chip does support OS-level control of this
+ * feature.
*/
extern u32 omap_features;
@@ -488,9 +495,10 @@ extern u32 omap_features;
#define OMAP3_HAS_192MHZ_CLK BIT(5)
#define OMAP3_HAS_IO_WAKEUP BIT(6)
#define OMAP3_HAS_SDRC BIT(7)
-#define OMAP4_HAS_MPU_1GHZ BIT(8)
-#define OMAP4_HAS_MPU_1_2GHZ BIT(9)
-#define OMAP4_HAS_MPU_1_5GHZ BIT(10)
+#define OMAP3_HAS_IO_CHAIN_CTRL BIT(8)
+#define OMAP4_HAS_MPU_1GHZ BIT(9)
+#define OMAP4_HAS_MPU_1_2GHZ BIT(10)
+#define OMAP4_HAS_MPU_1_5GHZ BIT(11)
#define OMAP3_HAS_FEATURE(feat,flag) \
@@ -507,12 +515,11 @@ OMAP3_HAS_FEATURE(isp, ISP)
OMAP3_HAS_FEATURE(192mhz_clk, 192MHZ_CLK)
OMAP3_HAS_FEATURE(io_wakeup, IO_WAKEUP)
OMAP3_HAS_FEATURE(sdrc, SDRC)
+OMAP3_HAS_FEATURE(io_chain_ctrl, IO_CHAIN_CTRL)
/*
* Runtime detection of OMAP4 features
*/
-extern u32 omap_features;
-
#define OMAP4_HAS_FEATURE(feat, flag) \
static inline unsigned int omap4_has_ ##feat(void) \
{ \
--
1.7.6.3
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