diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-baytrail.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-baytrail.c | 40 |
1 files changed, 21 insertions, 19 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 5f1ff4cc5c34..7d7ae97476e2 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -17,27 +17,31 @@ #include <linux/acpi.h> #include <linux/i2c.h> #include <linux/interrupt.h> + #include <asm/iosf_mbi.h> + #include "i2c-designware-core.h" #define SEMAPHORE_TIMEOUT 100 #define PUNIT_SEMAPHORE 0x7 +#define PUNIT_SEMAPHORE_BIT BIT(0) +#define PUNIT_SEMAPHORE_ACQUIRE BIT(1) static unsigned long acquired; static int get_sem(struct device *dev, u32 *sem) { - u32 reg_val; + u32 data; int ret; ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ, PUNIT_SEMAPHORE, - ®_val); + &data); if (ret) { dev_err(dev, "iosf failed to read punit semaphore\n"); return ret; } - *sem = reg_val & 0x1; + *sem = data & PUNIT_SEMAPHORE_BIT; return 0; } @@ -52,27 +56,29 @@ static void reset_semaphore(struct device *dev) return; } - data = data & 0xfffffffe; + data &= ~PUNIT_SEMAPHORE_BIT; if (iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE, - PUNIT_SEMAPHORE, data)) + PUNIT_SEMAPHORE, data)) dev_err(dev, "iosf failed to reset punit semaphore during write\n"); } -int baytrail_i2c_acquire(struct dw_i2c_dev *dev) +static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) { - u32 sem = 0; + u32 sem; int ret; unsigned long start, end; + might_sleep(); + if (!dev || !dev->dev) return -ENODEV; - if (!dev->acquire_lock) + if (!dev->release_lock) return 0; - /* host driver writes 0x2 to side band semaphore register */ + /* host driver writes to side band semaphore register */ ret = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE, - PUNIT_SEMAPHORE, 0x2); + PUNIT_SEMAPHORE, PUNIT_SEMAPHORE_ACQUIRE); if (ret) { dev_err(dev->dev, "iosf punit semaphore request failed\n"); return ret; @@ -81,7 +87,7 @@ int baytrail_i2c_acquire(struct dw_i2c_dev *dev) /* host driver waits for bit 0 to be set in semaphore register */ start = jiffies; end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT); - while (!time_after(jiffies, end)) { + do { ret = get_sem(dev->dev, &sem); if (!ret && sem) { acquired = jiffies; @@ -91,14 +97,14 @@ int baytrail_i2c_acquire(struct dw_i2c_dev *dev) } usleep_range(1000, 2000); - } + } while (time_before(jiffies, end)); dev_err(dev->dev, "punit semaphore timed out, resetting\n"); reset_semaphore(dev->dev); ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ, - PUNIT_SEMAPHORE, &sem); - if (!ret) + PUNIT_SEMAPHORE, &sem); + if (ret) dev_err(dev->dev, "iosf failed to read punit semaphore\n"); else dev_err(dev->dev, "PUNIT SEM: %d\n", sem); @@ -107,9 +113,8 @@ int baytrail_i2c_acquire(struct dw_i2c_dev *dev) return -ETIMEDOUT; } -EXPORT_SYMBOL(baytrail_i2c_acquire); -void baytrail_i2c_release(struct dw_i2c_dev *dev) +static void baytrail_i2c_release(struct dw_i2c_dev *dev) { if (!dev || !dev->dev) return; @@ -121,7 +126,6 @@ void baytrail_i2c_release(struct dw_i2c_dev *dev) dev_dbg(dev->dev, "punit semaphore held for %ums\n", jiffies_to_msecs(jiffies - acquired)); } -EXPORT_SYMBOL(baytrail_i2c_release); int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) { @@ -137,7 +141,6 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) return 0; status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host); - if (ACPI_FAILURE(status)) return 0; @@ -153,7 +156,6 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) return 0; } -EXPORT_SYMBOL(i2c_dw_eval_lock_support); MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>"); MODULE_DESCRIPTION("Baytrail I2C Semaphore driver"); |