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

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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: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
This commit is contained in:
Fabio Aiuto 2021-09-16 09:12:55 +02:00 committed by Chanwoo Choi
parent 3177308a94
commit 968bd3f038
2 changed files with 30 additions and 3 deletions
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2
drivers/extcon/Kconfig
View File

@ -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

31
drivers/extcon/extcon-axp288.c
View File

@ -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 @@ no_vbus:
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);