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i2c: omap: implement bus recovery 

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@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Felipe Balbi 2015-05-06 11:50:27 -05:00 committed by Wolfram Sang
parent e9a02a3d89
commit 9dcb0e7b99
1 changed files with 65 additions and 4 deletions
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69
drivers/i2c/busses/i2c-omap.c
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@ -482,10 +482,8 @@ 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);
}
@ -1210,6 +1208,68 @@ 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)
{
@ -1359,6 +1419,7 @@ 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;