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author | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2014-05-09 10:47:05 +0200 |
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committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2014-05-09 11:50:14 +0200 |
commit | d2a3e911390f9fc4d8c0ee4b3c7fc75f4fd3fd19 (patch) | |
tree | d71aae6d706d1f3b01da5f944e247abe308feea0 /drivers/i2c/fsl_i2c.c | |
parent | 7904b70885f3c589c239f6ac978f299a6744557f (diff) | |
parent | 173d294b94cfec10063a5be40934d6d8fb7981ce (diff) | |
download | u-boot-imx-d2a3e911390f9fc4d8c0ee4b3c7fc75f4fd3fd19.zip u-boot-imx-d2a3e911390f9fc4d8c0ee4b3c7fc75f4fd3fd19.tar.gz u-boot-imx-d2a3e911390f9fc4d8c0ee4b3c7fc75f4fd3fd19.tar.bz2 |
Merge branch 'u-boot/master'
Conflicts:
drivers/net/Makefile
(trivial merge)
Diffstat (limited to 'drivers/i2c/fsl_i2c.c')
-rw-r--r-- | drivers/i2c/fsl_i2c.c | 41 |
1 files changed, 34 insertions, 7 deletions
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c index 291ad94..aa159f8 100644 --- a/drivers/i2c/fsl_i2c.c +++ b/drivers/i2c/fsl_i2c.c @@ -423,18 +423,45 @@ fsl_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr, int alen, u8 *data, struct fsl_i2c *device = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; int i = -1; /* signal error */ u8 *a = (u8*)&addr; + int len = alen * -1; if (i2c_wait4bus(adap) < 0) return -1; - if ((!length || alen > 0) - && i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0 - && __i2c_write(adap, &a[4 - alen], alen) == alen) - i = 0; /* No error so far */ + /* To handle the need of I2C devices that require to write few bytes + * (more than 4 bytes of address as in the case of else part) + * of data before reading, Negative equivalent of length(bytes to write) + * is passed, but used the +ve part of len for writing data + */ + if (alen < 0) { + /* Generate a START and send the Address and + * the Tx Bytes to the slave. + * "START: Address: Write bytes data[len]" + * IF part supports writing any number of bytes in contrast + * to the else part, which supports writing address offset + * of upto 4 bytes only. + * bytes that need to be written are passed in + * "data", which will eventually keep the data READ, + * after writing the len bytes out of it + */ + if (i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0) + i = __i2c_write(adap, data, len); + + if (i != len) + return -1; - if (length && - i2c_write_addr(adap, dev, I2C_READ_BIT, alen ? 1 : 0) != 0) - i = __i2c_read(adap, data, length); + if (length && i2c_write_addr(adap, dev, I2C_READ_BIT, 1) != 0) + i = __i2c_read(adap, data, length); + } else { + if ((!length || alen > 0) && + i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0 && + __i2c_write(adap, &a[4 - alen], alen) == alen) + i = 0; /* No error so far */ + + if (length && + i2c_write_addr(adap, dev, I2C_READ_BIT, alen ? 1 : 0) != 0) + i = __i2c_read(adap, data, length); + } writeb(I2C_CR_MEN, &device->cr); |