Commit 968bd3f0 authored by Fabio Aiuto's avatar Fabio Aiuto Committed by Chanwoo Choi
Browse files

extcon: extcon-axp288: Use P-Unit semaphore lock for register accesses 



use low level P-Unit semaphore lock for axp288 register
accesses directly and for more than one access a time,
to reduce the number of times this semaphore is locked
and released which is an expensive operation.

i2c-bus to the XPower is shared between the kernel and the
SoCs P-Unit. The P-Unit has a semaphore wich the kernel must
lock for axp288 register accesses. When the P-Unit semaphore
is locked CPU and GPU power states cannot change or the system
will freeze.

The P-Unit semaphore lock is already managed inside the regmap
access logic, but for each access the semaphore is locked and
released. So use directly iosf_mbi_(un)block_punit_i2c_access(),
we are safe in doing so because nested calls to the same
semaphore are turned to nops.

Suggested-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Tested-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarFabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
parent 3177308a

drivers/extcon/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ config EXTCON_ADC_JACK 


config EXTCON_AXP288

	tristate "X-Power AXP288 EXTCON support"

	depends on MFD_AXP20X && USB_SUPPORT && X86 && ACPI

	depends on MFD_AXP20X && USB_SUPPORT && X86 && ACPI && IOSF_MBI

	select USB_ROLE_SWITCH

	help

	  Say Y here to enable support for USB peripheral detection

drivers/extcon/extcon-axp288.c

+29 −2
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 


#include <asm/cpu_device_id.h>

#include <asm/intel-family.h>

#include <asm/iosf_mbi.h>



/* Power source status register */

#define PS_STAT_VBUS_TRIGGER		BIT(0)
@@ -215,6 +216,10 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info) 
	unsigned int cable = info->previous_cable;

	bool vbus_attach = false;



	ret = iosf_mbi_block_punit_i2c_access();

	if (ret < 0)

		return ret;



	vbus_attach = axp288_get_vbus_attach(info);

	if (!vbus_attach)

		goto no_vbus;
@@ -253,6 +258,8 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info) 
	}



no_vbus:

	iosf_mbi_unblock_punit_i2c_access();



	extcon_set_state_sync(info->edev, info->previous_cable, false);

	if (info->previous_cable == EXTCON_CHG_USB_SDP)

		extcon_set_state_sync(info->edev, EXTCON_USB, false);
@@ -275,6 +282,8 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info) 
	return 0;



dev_det_ret:

	iosf_mbi_unblock_punit_i2c_access();



	if (ret < 0)

		dev_err(info->dev, "failed to detect BC Mod\n");
@@ -305,13 +314,23 @@ static irqreturn_t axp288_extcon_isr(int irq, void *data) 
	return IRQ_HANDLED;

}



static void axp288_extcon_enable(struct axp288_extcon_info *info)

static int axp288_extcon_enable(struct axp288_extcon_info *info)

{

	int ret = 0;



	ret = iosf_mbi_block_punit_i2c_access();

	if (ret < 0)

		return ret;



	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,

						BC_GLOBAL_RUN, 0);

	/* Enable the charger detection logic */

	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,

					BC_GLOBAL_RUN, BC_GLOBAL_RUN);



	iosf_mbi_unblock_punit_i2c_access();



	return ret;

}



static void axp288_put_role_sw(void *data)
@@ -384,10 +403,16 @@ static int axp288_extcon_probe(struct platform_device *pdev) 
		}

	}



	ret = iosf_mbi_block_punit_i2c_access();

	if (ret < 0)

		return ret;



	info->vbus_attach = axp288_get_vbus_attach(info);



	axp288_extcon_log_rsi(info);



	iosf_mbi_unblock_punit_i2c_access();



	/* Initialize extcon device */

	info->edev = devm_extcon_dev_allocate(&pdev->dev,

					      axp288_extcon_cables);
@@ -441,7 +466,9 @@ static int axp288_extcon_probe(struct platform_device *pdev) 
	}



	/* Start charger cable type detection */

	axp288_extcon_enable(info);

	ret = axp288_extcon_enable(info);

	if (ret < 0)

		return ret;



	device_init_wakeup(dev, true);

	platform_set_drvdata(pdev, info);