1 files changed, 58 insertions, 25 deletions

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 1590ad0a8081..1749a0f5a9fa 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>
 
@@ -23,19 +24,29 @@
 
 #define SEMAPHORE_TIMEOUT	100
 #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 int get_sem(struct device *dev, u32 *sem)
+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, PUNIT_SEMAPHORE, &data);
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data);
 	if (ret) {
-		dev_err(dev, "iosf failed to read punit semaphore\n");
+		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
 		return ret;
 	}
 
@@ -44,22 +55,22 @@ static int get_sem(struct device *dev, u32 *sem)
 	return 0;
 }
 
-static void reset_semaphore(struct device *dev)
+static void reset_semaphore(struct dw_i2c_dev *dev)
 {
-	u32 data;
+	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");
 
-	if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data)) {
-		dev_err(dev, "iosf failed to reset punit semaphore during read\n");
-		return;
-	}
+	pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
 
-	data &= ~PUNIT_SEMAPHORE_BIT;
-	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data))
-		dev_err(dev, "iosf failed to reset punit semaphore during write\n");
+	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 = get_sem_addr(dev);
 	u32 sem = PUNIT_SEMAPHORE_ACQUIRE;
 	int ret;
 	unsigned long start, end;
@@ -72,18 +83,29 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	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);
+
 	/* host driver writes to side band semaphore register */
-	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, sem);
+	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");
-		return ret;
+		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->dev, &sem);
+		ret = get_sem(dev, &sem);
 		if (!ret && sem) {
 			acquired = jiffies;
 			dev_dbg(dev->dev, "punit semaphore acquired after %ums\n",
@@ -95,9 +117,10 @@ 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");
-	reset_semaphore(dev->dev);
+out:
+	reset_semaphore(dev);
 
-	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &sem);
+	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
@@ -116,12 +139,12 @@ static void baytrail_i2c_release(struct dw_i2c_dev *dev)
 	if (!dev->acquire_lock)
 		return;
 
-	reset_semaphore(dev->dev);
+	reset_semaphore(dev);
 	dev_dbg(dev->dev, "punit semaphore held for %ums\n",
 		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;
@@ -138,15 +161,25 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
 	if (ACPI_FAILURE(status))
 		return 0;
 
-	if (shared_host) {
-		dev_info(dev->dev, "I2C bus managed by PUNIT\n");
-		dev->acquire_lock = baytrail_i2c_acquire;
-		dev->release_lock = baytrail_i2c_release;
-		dev->pm_runtime_disabled = true;
-	}
+	if (!shared_host)
+		return 0;
 
 	if (!iosf_mbi_available())
 		return -EPROBE_DEFER;
 
+	dev_info(dev->dev, "I2C bus managed by PUNIT\n");
+	dev->acquire_lock = baytrail_i2c_acquire;
+	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);
+}