diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 471d06eb84345da49f9bbbae272949c5b3c58f64..f83f6b8892b5a6505fdaabe30dae48a43ed6dce7 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -90,6 +90,8 @@
#define TWSI_INT_CORE_EN BIT_ULL(6)
#define TWSI_INT_SDA_OVR BIT_ULL(8)
#define TWSI_INT_SCL_OVR BIT_ULL(9)
+#define TWSI_INT_SDA BIT_ULL(10)
+#define TWSI_INT_SCL BIT_ULL(11)
struct octeon_i2c {
wait_queue_head_t queue;
@@ -152,6 +154,17 @@ static u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg)
#define octeon_i2c_stat_read(i2c) \
octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT)
+/**
+ * octeon_i2c_read_int - read the TWSI_INT register
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns the value of the register.
+ */
+static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
+{
+ return __raw_readq(i2c->twsi_base + TWSI_INT);
+}
+
/**
* octeon_i2c_write_int - write the TWSI_INT register
* @i2c: The struct octeon_i2c
@@ -182,33 +195,6 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
octeon_i2c_write_int(i2c, 0);
}
-/**
- * octeon_i2c_unblock - unblock the bus
- * @i2c: The struct octeon_i2c
- *
- * If there was a reset while a device was driving 0 to bus, bus is blocked.
- * We toggle it free manually by some clock cycles and send a stop.
- */
-static void octeon_i2c_unblock(struct octeon_i2c *i2c)
-{
- int i;
-
- dev_dbg(i2c->dev, "%s\n", __func__);
-
- for (i = 0; i < 9; i++) {
- octeon_i2c_write_int(i2c, 0);
- udelay(5);
- octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
- udelay(5);
- }
- /* hand-crank a STOP */
- octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
- udelay(5);
- octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
- udelay(5);
- octeon_i2c_write_int(i2c, 0);
-}
-
/* interrupt service routine */
static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
{
@@ -371,6 +357,17 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
return -EIO;
}
+static int octeon_i2c_recovery(struct octeon_i2c *i2c)
+{
+ int ret;
+
+ ret = i2c_recover_bus(&i2c->adap);
+ if (ret)
+ /* recover failed, try hardware re-init */
+ ret = octeon_i2c_init_lowlevel(i2c);
+ return ret;
+}
+
/**
* octeon_i2c_start - send START to the bus
* @i2c: The struct octeon_i2c
@@ -379,34 +376,23 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
*/
static int octeon_i2c_start(struct octeon_i2c *i2c)
{
- int result;
- u8 data;
+ int ret;
+ u8 stat;
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
+ ret = octeon_i2c_wait(i2c);
+ if (ret)
+ goto error;
- result = octeon_i2c_wait(i2c);
- if (result) {
- if (octeon_i2c_stat_read(i2c) == STAT_IDLE) {
- /*
- * Controller refused to send start flag May
- * be a client is holding SDA low - let's try
- * to free it.
- */
- octeon_i2c_unblock(i2c);
- octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
- result = octeon_i2c_wait(i2c);
- }
- if (result)
- return result;
- }
-
- data = octeon_i2c_stat_read(i2c);
- if ((data != STAT_START) && (data != STAT_REP_START)) {
- dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);
- return -EIO;
- }
+ stat = octeon_i2c_stat_read(i2c);
+ if (stat == STAT_START || stat == STAT_REP_START)
+ /* START successful, bail out */
+ return 0;
- return 0;
+error:
+ /* START failed, try to recover */
+ ret = octeon_i2c_recovery(i2c);
+ return (ret) ? ret : -EAGAIN;
}
/* send STOP to the bus */
@@ -431,10 +417,6 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
{
int i, result;
- result = octeon_i2c_start(i2c);
- if (result)
- return result;
-
octeon_i2c_data_write(i2c, target << 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
@@ -479,10 +461,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
if (length < 1)
return -EINVAL;
- result = octeon_i2c_start(i2c);
- if (result)
- return result;
-
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
@@ -546,10 +524,10 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
for (i = 0; ret == 0 && i < num; i++) {
struct i2c_msg *pmsg = &msgs[i];
- dev_dbg(i2c->dev,
- "Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n",
- pmsg->flags & I2C_M_RD ? "read" : "write",
- pmsg->len, pmsg->addr, i + 1, num);
+ ret = octeon_i2c_start(i2c);
+ if (ret)
+ return ret;
+
if (pmsg->flags & I2C_M_RD)
ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
&pmsg->len, pmsg->flags & I2C_M_RECV_LEN);
@@ -562,6 +540,60 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
return (ret != 0) ? ret : num;
}
+static int octeon_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ u64 state;
+
+ state = octeon_i2c_read_int(i2c);
+ return state & TWSI_INT_SCL;
+}
+
+static void octeon_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
+}
+
+static int octeon_i2c_get_sda(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ u64 state;
+
+ state = octeon_i2c_read_int(i2c);
+ return state & TWSI_INT_SDA;
+}
+
+static void octeon_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ /*
+ * The stop resets the state machine, does not _transmit_ STOP unless
+ * engine was active.
+ */
+ octeon_i2c_stop(i2c);
+
+ octeon_i2c_write_int(i2c, 0);
+}
+
+static void octeon_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+
+ octeon_i2c_write_int(i2c, 0);
+}
+
+static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {
+ .recover_bus = i2c_generic_scl_recovery,
+ .get_scl = octeon_i2c_get_scl,
+ .set_scl = octeon_i2c_set_scl,
+ .get_sda = octeon_i2c_get_sda,
+ .prepare_recovery = octeon_i2c_prepare_recovery,
+ .unprepare_recovery = octeon_i2c_unprepare_recovery,
+};
+
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
@@ -642,6 +674,7 @@ static int octeon_i2c_probe(struct platform_device *pdev)
i2c->adap = octeon_i2c_ops;
i2c->adap.timeout = msecs_to_jiffies(2);
i2c->adap.retries = 5;
+ i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.dev.of_node = node;
i2c_set_adapdata(&i2c->adap, i2c);