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path: root/drivers/i2c/busses/i2c-designware-baytrail.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-designware-baytrail.c')
-rw-r--r--drivers/i2c/busses/i2c-designware-baytrail.c83
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);
+}