implement bus recovery methods for i2c-omap
so we can recover from situations where SCL/SDA
are stuck low.
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
rebased on 4.1-rc2, switched over to generic i2c recover mechanism,
retested on am437x sk and beaglebone black.
drivers/i2c/busses/i2c-omap.c | 69 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 65 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 0e894193accf..dcf559ac92c5 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -481,10 +481,8 @@ static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
timeout = jiffies + OMAP_I2C_TIMEOUT;
while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
- if (time_after(jiffies, timeout)) {
- dev_warn(dev->dev, "timeout waiting for bus ready\n");
- return -ETIMEDOUT;
- }
+ if (time_after(jiffies, timeout))
+ return i2c_recover_bus(&dev->adapter);
msleep(1);
}
@@ -1209,6 +1207,68 @@ MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
#define OMAP_I2C_SCHEME_0 0
#define OMAP_I2C_SCHEME_1 1
+static int omap_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+ return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
+}
+
+static int omap_i2c_get_sda(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+ return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
+}
+
+static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+ if (val)
+ reg |= OMAP_I2C_SYSTEST_SCL_O;
+ else
+ reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+ omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+ reg |= OMAP_I2C_SYSTEST_ST_EN;
+ omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+ reg &= ~OMAP_I2C_SYSTEST_ST_EN;
+ omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
+ .get_scl = omap_i2c_get_scl,
+ .get_sda = omap_i2c_get_sda,
+ .set_scl = omap_i2c_set_scl,
+ .prepare_recovery = omap_i2c_prepare_recovery,
+ .unprepare_recovery = omap_i2c_unprepare_recovery,
+ .recover_bus = i2c_generic_scl_recovery,
+};
+
static int
omap_i2c_probe(struct platform_device *pdev)
{
@@ -1358,6 +1418,7 @@ omap_i2c_probe(struct platform_device *pdev)
adap->algo = &omap_i2c_algo;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
+ adap->bus_recovery_info = &omap_i2c_bus_recovery_info;
/* i2c device drivers may be active on return from add_adapter() */
adap->nr = pdev->id;
--
2.4.0.rc3
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