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Commit b02b9172 authored by Paul Walmsley's avatar Paul Walmsley Committed by Kevin Hilman
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ARM: OMAP3: PM: fix I/O wakeup and I/O chain clock control detection 

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@gmail.com> for reporting this problem
and doing some testing to help isolate the cause.  Thanks to Steve
Sakoman <sakoman@gmail.com> for catching a bug in the first version of
this patch.  Thanks to Russell King <linux@arm.linux.org.uk> for
comments.

Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
Cc: Dave Hylands <dhylands@gmail.com>
Cc: Steve Sakoman <sakoman@gmail.com>
Tested-by: default avatarSteve Sakoman <sakoman@gmail.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Signed-off-by: default avatarKevin Hilman <khilman@ti.com>
parent ff2f8e5f

arch/arm/mach-omap2/id.c

+4 −1
Original line number Diff line number Diff line
@@ -201,8 +201,11 @@ 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 (cpu_is_omap3630() || omap_rev() == OMAP3430_REV_ES3_1 ||

	    omap_rev() == OMAP3430_REV_ES3_1_2)

		omap_features |= OMAP3_HAS_IO_CHAIN_CTRL;



	omap_features |= OMAP3_HAS_SDRC;

arch/arm/mach-omap2/pm34xx.c

+22 −21
Original line number Diff line number Diff line
@@ -99,7 +99,6 @@ 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 */
@@ -109,19 +108,16 @@ static void omap3_enable_io_chain(void) 
		 OMAP3430_ST_IO_CHAIN_MASK)) {

		timeout++;

		if (timeout > 1000) {

				printk(KERN_ERR "Wake up daisy chain "

				       "activation failed.\n");

			pr_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);

}
@@ -375,6 +371,7 @@ 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);

		if (omap3_has_io_chain_ctrl())

			omap3_enable_io_chain();

	}
@@ -478,6 +475,7 @@ void omap_sram_idle(void) 
	     core_next_state < PWRDM_POWER_ON)) {

		omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,

					     PM_WKEN);

		if (omap3_has_io_chain_ctrl())

			omap3_disable_io_chain();

	}
@@ -871,6 +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

arch/arm/plat-omap/include/plat/cpu.h

+12 −5
Original line number Diff line number Diff line
@@ -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)	\

{							\