diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-common.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-common.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index 48914dfc8ce8..d1c93acabfcf 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -94,6 +94,40 @@ void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset) } } +/** + * i2c_dw_set_reg_access() - Set register access flags + * @dev: device private data + * + * Autodetects needed register access mode and sets access flags accordingly. + * This must be called before doing any other register access. + */ +int i2c_dw_set_reg_access(struct dw_i2c_dev *dev) +{ + u32 reg; + int ret; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + + reg = dw_readl(dev, DW_IC_COMP_TYPE); + i2c_dw_release_lock(dev); + + if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) { + /* Configure register endianess access */ + dev->flags |= ACCESS_SWAP; + } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) { + /* Configure register access mode 16bit */ + dev->flags |= ACCESS_16BIT; + } else if (reg != DW_IC_COMP_TYPE_VALUE) { + dev_err(dev->dev, + "Unknown Synopsys component type: 0x%08x\n", reg); + return -ENODEV; + } + + return 0; +} + u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset) { /* |