diff options
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/i2c-designware-baytrail.c | 125 |
1 files changed, 2 insertions, 123 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index a2a275cfc1f6..b2ba4de4e204 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -3,139 +3,23 @@ * Intel BayTrail PMIC I2C bus semaphore implementaion * Copyright (c) 2014, Intel Corporation. */ -#include <linux/delay.h> #include <linux/device.h> #include <linux/acpi.h> #include <linux/i2c.h> #include <linux/interrupt.h> -#include <linux/pm_qos.h> #include <asm/iosf_mbi.h> #include "i2c-designware-core.h" -#define SEMAPHORE_TIMEOUT 500 -#define PUNIT_SEMAPHORE 0x7 -#define PUNIT_SEMAPHORE_CHT 0x10e -#define PUNIT_SEMAPHORE_BIT BIT(0) -#define PUNIT_SEMAPHORE_ACQUIRE BIT(1) - -static unsigned long acquired; - -static u32 get_sem_addr(struct dw_i2c_dev *dev) -{ - if (dev->flags & MODEL_CHERRYTRAIL) - return PUNIT_SEMAPHORE_CHT; - else - return PUNIT_SEMAPHORE; -} - -static int get_sem(struct dw_i2c_dev *dev, u32 *sem) -{ - u32 addr = get_sem_addr(dev); - u32 data; - int ret; - - ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data); - if (ret) { - dev_err(dev->dev, "iosf failed to read punit semaphore\n"); - return ret; - } - - *sem = data & PUNIT_SEMAPHORE_BIT; - - return 0; -} - -static void reset_semaphore(struct dw_i2c_dev *dev) -{ - if (iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, get_sem_addr(dev), - 0, PUNIT_SEMAPHORE_BIT)) - dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); - - pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE); - - iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_END, - NULL); - iosf_mbi_punit_release(); -} - static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) { - u32 addr; - u32 sem = PUNIT_SEMAPHORE_ACQUIRE; - int ret; - unsigned long start, end; - - might_sleep(); - - if (!dev || !dev->dev) - return -ENODEV; - - if (!dev->release_lock) - return 0; - - iosf_mbi_punit_acquire(); - iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_BEGIN, - NULL); - - /* - * 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); - - addr = get_sem_addr(dev); - - /* host driver writes to side band semaphore register */ - ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, sem); - if (ret) { - dev_err(dev->dev, "iosf punit semaphore request failed\n"); - goto out; - } - - /* host driver waits for bit 0 to be set in semaphore register */ - start = jiffies; - end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT); - do { - ret = get_sem(dev, &sem); - if (!ret && sem) { - acquired = jiffies; - dev_dbg(dev->dev, "punit semaphore acquired after %ums\n", - jiffies_to_msecs(jiffies - start)); - return 0; - } - - usleep_range(1000, 2000); - } 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, addr, &sem); - if (ret) - dev_err(dev->dev, "iosf failed to read punit semaphore\n"); - else - dev_err(dev->dev, "PUNIT SEM: %d\n", sem); - - WARN_ON(1); - - return -ETIMEDOUT; + return iosf_mbi_block_punit_i2c_access(); } static void baytrail_i2c_release(struct dw_i2c_dev *dev) { - if (!dev || !dev->dev) - return; - - if (!dev->acquire_lock) - return; - - reset_semaphore(dev); - dev_dbg(dev->dev, "punit semaphore held for %ums\n", - jiffies_to_msecs(jiffies - acquired)); + iosf_mbi_unblock_punit_i2c_access(); } int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) @@ -166,14 +50,9 @@ int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) dev->release_lock = baytrail_i2c_release; dev->pm_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); } |