diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-baytrail.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-baytrail.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index cf022226b693..650a700f215e 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -16,6 +16,7 @@ #include <linux/acpi.h> #include <linux/i2c.h> #include <linux/interrupt.h> +#include <linux/pm_qos.h> #include <asm/iosf_mbi.h> @@ -56,6 +57,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev) data &= ~PUNIT_SEMAPHORE_BIT; if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data)) dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); + + pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE); } static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) @@ -72,11 +75,18 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) if (!dev->release_lock) return 0; + /* + * Disallow the CPU to enter C6 or C7 state, entering these states + * requires the punit to talk to the pmic and if this happens while + * we're holding the semaphore, the SoC hangs. + */ + pm_qos_update_request(&dev->pm_qos, 0); + /* host driver writes to side band semaphore register */ ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, sem); if (ret) { dev_err(dev->dev, "iosf punit semaphore request failed\n"); - return ret; + goto out; } /* host driver waits for bit 0 to be set in semaphore register */ @@ -95,6 +105,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) } while (time_before(jiffies, end)); dev_err(dev->dev, "punit semaphore timed out, resetting\n"); +out: reset_semaphore(dev); ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &sem); @@ -121,7 +132,7 @@ static void baytrail_i2c_release(struct dw_i2c_dev *dev) jiffies_to_msecs(jiffies - acquired)); } -int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) +int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { acpi_status status; unsigned long long shared_host = 0; @@ -149,5 +160,14 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) dev->release_lock = baytrail_i2c_release; dev->pm_runtime_disabled = true; + pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY, + PM_QOS_DEFAULT_VALUE); + return 0; } + +void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) +{ + if (dev->acquire_lock) + pm_qos_remove_request(&dev->pm_qos); +} |
