diff options
| -rw-r--r-- | drivers/i2c/designware_i2c.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index c6a2072..3616e21 100644 --- a/drivers/i2c/designware_i2c.c +++ b/drivers/i2c/designware_i2c.c @@ -18,6 +18,12 @@ #include <dm/device_compat.h> #include <linux/err.h> +/* + * This assigned unique hex value is constant and is derived from the two ASCII + * letters 'DW' followed by a 16-bit unsigned number + */ +#define DW_I2C_COMP_TYPE 0x44570140 + #ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable) { @@ -766,6 +772,17 @@ int designware_i2c_ofdata_to_platdata(struct udevice *bus) int designware_i2c_probe(struct udevice *bus) { struct dw_i2c *priv = dev_get_priv(bus); + uint comp_type; + + comp_type = readl(&priv->regs->comp_type); + if (comp_type != DW_I2C_COMP_TYPE) { + log_err("I2C bus %s has unknown type %#x\n", bus->name, + comp_type); + return -ENXIO; + } + + log_info("I2C bus %s version %#x\n", bus->name, + readl(&priv->regs->comp_version)); return __dw_i2c_init(priv->regs, 0, 0); } |