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Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/…
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…kernel/git/wsa/linux

Pull i2c fix from Wolfram Sang:
 "I2C has a revert to fix a regression"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Revert "i2c: designware: detect when dynamic tar update is possible"
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Linus Torvalds committed Feb 17, 2017
2 parents 6adfd6a + 12688dc commit 444a034
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Showing 2 changed files with 11 additions and 35 deletions.
45 changes: 11 additions & 34 deletions drivers/i2c/busses/i2c-designware-core.c
Original file line number Diff line number Diff line change
Expand Up @@ -475,30 +475,28 @@ 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_tar = 0;
u32 ic_con, ic_tar = 0;

/* Disable the adapter */
__i2c_dw_enable_and_wait(dev, false);

/* if the slave address is ten bit address, enable 10BITADDR */
if (dev->dynamic_tar_update_enabled) {
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 I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
* mode has to be enabled via bit 12 of IC_TAR register,
* otherwise bit 4 of IC_CON is used.
* 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.
*/
if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
ic_tar = DW_IC_TAR_10BITADDR_MASTER;
ic_tar = DW_IC_TAR_10BITADDR_MASTER;
} else {
u32 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;
else
ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
dw_writel(dev, ic_con, DW_IC_CON);
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
* if applicable.
Expand Down Expand Up @@ -963,34 +961,13 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
int r;
u32 reg;

init_completion(&dev->cmd_complete);

r = i2c_dw_init(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;
Expand Down
1 change: 0 additions & 1 deletion drivers/i2c/busses/i2c-designware-core.h
Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,6 @@ struct dw_i2c_dev {
int (*acquire_lock)(struct dw_i2c_dev *dev);
void (*release_lock)(struct dw_i2c_dev *dev);
bool pm_runtime_disabled;
bool dynamic_tar_update_enabled;
};

#define ACCESS_SWAP 0x00000001
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