summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-designware-core.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-core.c')
-rw-r--r--drivers/i2c/busses/i2c-designware-core.c196
1 files changed, 141 insertions, 55 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index c6922b806fb7..52a603a01ddd 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -42,6 +42,8 @@
#define DW_IC_SS_SCL_LCNT 0x18
#define DW_IC_FS_SCL_HCNT 0x1c
#define DW_IC_FS_SCL_LCNT 0x20
+#define DW_IC_HS_SCL_HCNT 0x24
+#define DW_IC_HS_SCL_LCNT 0x28
#define DW_IC_INTR_STAT 0x2c
#define DW_IC_INTR_MASK 0x30
#define DW_IC_RAW_INTR_STAT 0x34
@@ -89,12 +91,17 @@
DW_IC_INTR_TX_ABRT | \
DW_IC_INTR_STOP_DET)
-#define DW_IC_STATUS_ACTIVITY 0x1
+#define DW_IC_STATUS_ACTIVITY 0x1
+#define DW_IC_STATUS_TFE BIT(2)
+#define DW_IC_STATUS_MST_ACTIVITY BIT(5)
#define DW_IC_ERR_TX_ABRT 0x1
#define DW_IC_TAR_10BITADDR_MASTER BIT(12)
+#define DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH (BIT(2) | BIT(3))
+#define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK GENMASK(3, 2)
+
/*
* status codes
*/
@@ -252,10 +259,15 @@ static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
{
+ dw_writel(dev, enable, DW_IC_ENABLE);
+}
+
+static void __i2c_dw_enable_and_wait(struct dw_i2c_dev *dev, bool enable)
+{
int timeout = 100;
do {
- dw_writel(dev, enable, DW_IC_ENABLE);
+ __i2c_dw_enable(dev, enable);
if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
return;
@@ -282,6 +294,28 @@ static unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
return dev->get_clk_rate_khz(dev);
}
+static int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
+{
+ int ret;
+
+ if (!dev->acquire_lock)
+ return 0;
+
+ ret = dev->acquire_lock(dev);
+ if (!ret)
+ return 0;
+
+ dev_err(dev->dev, "couldn't acquire bus ownership\n");
+
+ return ret;
+}
+
+static void i2c_dw_release_lock(struct dw_i2c_dev *dev)
+{
+ if (dev->release_lock)
+ dev->release_lock(dev);
+}
+
/**
* i2c_dw_init() - initialize the designware i2c master hardware
* @dev: device private data
@@ -293,17 +327,13 @@ static unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
int i2c_dw_init(struct dw_i2c_dev *dev)
{
u32 hcnt, lcnt;
- u32 reg;
+ u32 reg, comp_param1;
u32 sda_falling_time, scl_falling_time;
int ret;
- if (dev->acquire_lock) {
- ret = dev->acquire_lock(dev);
- if (ret) {
- dev_err(dev->dev, "couldn't acquire bus ownership\n");
- return ret;
- }
- }
+ ret = i2c_dw_acquire_lock(dev);
+ if (ret)
+ return ret;
reg = dw_readl(dev, DW_IC_COMP_TYPE);
if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
@@ -315,13 +345,14 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
} else if (reg != DW_IC_COMP_TYPE_VALUE) {
dev_err(dev->dev, "Unknown Synopsys component type: "
"0x%08x\n", reg);
- if (dev->release_lock)
- dev->release_lock(dev);
+ i2c_dw_release_lock(dev);
return -ENODEV;
}
+ comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
+
/* Disable the adapter */
- __i2c_dw_enable(dev, false);
+ __i2c_dw_enable_and_wait(dev, false);
/* set standard and fast speed deviders for high/low periods */
@@ -347,8 +378,11 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
- /* Set SCL timing parameters for fast-mode */
- if (dev->fs_hcnt && dev->fs_lcnt) {
+ /* Set SCL timing parameters for fast-mode or fast-mode plus */
+ if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
+ hcnt = dev->fp_hcnt;
+ lcnt = dev->fp_lcnt;
+ } else if (dev->fs_hcnt && dev->fs_lcnt) {
hcnt = dev->fs_hcnt;
lcnt = dev->fs_lcnt;
} else {
@@ -366,6 +400,23 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+ if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
+ DW_IC_CON_SPEED_HIGH) {
+ if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
+ != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
+ dev_err(dev->dev, "High Speed not supported!\n");
+ dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
+ dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+ } else if (dev->hs_hcnt && dev->hs_lcnt) {
+ hcnt = dev->hs_hcnt;
+ lcnt = dev->hs_lcnt;
+ dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
+ dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
+ dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
+ hcnt, lcnt);
+ }
+ }
+
/* Configure SDA Hold Time if required */
if (dev->sda_hold_time) {
reg = dw_readl(dev, DW_IC_COMP_VERSION);
@@ -383,8 +434,8 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
/* configure the i2c master */
dw_writel(dev, dev->master_cfg , DW_IC_CON);
- if (dev->release_lock)
- dev->release_lock(dev);
+ i2c_dw_release_lock(dev);
+
return 0;
}
EXPORT_SYMBOL_GPL(i2c_dw_init);
@@ -411,27 +462,45 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
- u32 ic_con, ic_tar = 0;
+ u32 ic_tar = 0;
+ bool enabled;
- /* Disable the adapter */
- __i2c_dw_enable(dev, false);
+ enabled = dw_readl(dev, DW_IC_ENABLE_STATUS) & 1;
+
+ if (enabled) {
+ u32 ic_status;
+
+ /*
+ * Only disable adapter if ic_tar and ic_con can't be
+ * dynamically updated
+ */
+ ic_status = dw_readl(dev, DW_IC_STATUS);
+ if (!dev->dynamic_tar_update_enabled ||
+ (ic_status & DW_IC_STATUS_MST_ACTIVITY) ||
+ !(ic_status & DW_IC_STATUS_TFE)) {
+ __i2c_dw_enable_and_wait(dev, false);
+ enabled = false;
+ }
+ }
/* if the slave address is ten bit address, enable 10BITADDR */
- ic_con = dw_readl(dev, DW_IC_CON);
- if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
- ic_con |= DW_IC_CON_10BITADDR_MASTER;
+ if (dev->dynamic_tar_update_enabled) {
/*
* If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
- * mode has to be enabled via bit 12 of IC_TAR register.
- * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
- * detected from registers.
+ * mode has to be enabled via bit 12 of IC_TAR register,
+ * otherwise bit 4 of IC_CON is used.
*/
- ic_tar = DW_IC_TAR_10BITADDR_MASTER;
+ if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+ ic_tar = DW_IC_TAR_10BITADDR_MASTER;
} else {
- ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
- }
+ u32 ic_con = dw_readl(dev, DW_IC_CON);
- dw_writel(dev, ic_con, DW_IC_CON);
+ if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+ ic_con |= DW_IC_CON_10BITADDR_MASTER;
+ else
+ ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
+ dw_writel(dev, ic_con, DW_IC_CON);
+ }
/*
* Set the slave (target) address and enable 10-bit addressing mode
@@ -442,8 +511,8 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
/* enforce disabled interrupts (due to HW issues) */
i2c_dw_disable_int(dev);
- /* Enable the adapter */
- __i2c_dw_enable(dev, true);
+ if (!enabled)
+ __i2c_dw_enable(dev, true);
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
@@ -624,7 +693,8 @@ static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
}
/*
- * Prepare controller for a transaction and call i2c_dw_xfer_msg
+ * Prepare controller for a transaction and start transfer by calling
+ * i2c_dw_xfer_init()
*/
static int
i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
@@ -647,13 +717,9 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
dev->abort_source = 0;
dev->rx_outstanding = 0;
- if (dev->acquire_lock) {
- ret = dev->acquire_lock(dev);
- if (ret) {
- dev_err(dev->dev, "couldn't acquire bus ownership\n");
- goto done_nolock;
- }
- }
+ ret = i2c_dw_acquire_lock(dev);
+ if (ret)
+ goto done_nolock;
ret = i2c_dw_wait_bus_not_busy(dev);
if (ret < 0)
@@ -671,16 +737,6 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
goto done;
}
- /*
- * We must disable the adapter before returning and signaling the end
- * of the current transfer. Otherwise the hardware might continue
- * generating interrupts which in turn causes a race condition with
- * the following transfer. Needs some more investigation if the
- * additional interrupts are a hardware bug or this driver doesn't
- * handle them correctly yet.
- */
- __i2c_dw_enable(dev, false);
-
if (dev->msg_err) {
ret = dev->msg_err;
goto done;
@@ -700,8 +756,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
ret = -EIO;
done:
- if (dev->release_lock)
- dev->release_lock(dev);
+ i2c_dw_release_lock(dev);
done_nolock:
pm_runtime_mark_last_busy(dev->dev);
@@ -818,9 +873,19 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
*/
tx_aborted:
- if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
+ if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
+ || dev->msg_err) {
+ /*
+ * We must disable interruts before returning and signaling
+ * the end of the current transfer. Otherwise the hardware
+ * might continue generating interrupts for non-existent
+ * transfers.
+ */
+ i2c_dw_disable_int(dev);
+ dw_readl(dev, DW_IC_CLR_INTR);
+
complete(&dev->cmd_complete);
- else if (unlikely(dev->accessor_flags & ACCESS_INTR_MASK)) {
+ } else if (unlikely(dev->accessor_flags & ACCESS_INTR_MASK)) {
/* workaround to trigger pending interrupt */
stat = dw_readl(dev, DW_IC_INTR_MASK);
i2c_dw_disable_int(dev);
@@ -833,7 +898,7 @@ tx_aborted:
void i2c_dw_disable(struct dw_i2c_dev *dev)
{
/* Disable controller */
- __i2c_dw_enable(dev, false);
+ __i2c_dw_enable_and_wait(dev, false);
/* Disable all interupts */
dw_writel(dev, 0, DW_IC_INTR_MASK);
@@ -857,6 +922,7 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
int r;
+ u32 reg;
init_completion(&dev->cmd_complete);
@@ -864,6 +930,26 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
if (r)
return r;
+ r = i2c_dw_acquire_lock(dev);
+ if (r)
+ return r;
+
+ /*
+ * Test if dynamic TAR update is enabled in this controller by writing
+ * to IC_10BITADDR_MASTER field in IC_CON: when it is enabled this
+ * field is read-only so it should not succeed
+ */
+ reg = dw_readl(dev, DW_IC_CON);
+ dw_writel(dev, reg ^ DW_IC_CON_10BITADDR_MASTER, DW_IC_CON);
+
+ if ((dw_readl(dev, DW_IC_CON) & DW_IC_CON_10BITADDR_MASTER) ==
+ (reg & DW_IC_CON_10BITADDR_MASTER)) {
+ dev->dynamic_tar_update_enabled = true;
+ dev_dbg(dev->dev, "Dynamic TAR update enabled");
+ }
+
+ i2c_dw_release_lock(dev);
+
snprintf(adap->name, sizeof(adap->name),
"Synopsys DesignWare I2C adapter");
adap->retries = 3;
OpenPOWER on IntegriCloud