rockchip: i2c: fix >32 byte reads

The hw can read up to 32 bytes at a time. If we need
more than one chunk, we have to enter the plain RX mode.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
This commit is contained in:
Wadim Egorov 2017-08-03 13:48:11 +02:00 committed by Philipp Tomsich
parent 313bbcf0ea
commit 5deaa53028

View file

@ -164,6 +164,7 @@ static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
uint rxdata;
uint i, j;
int err;
bool snd_chunk = false;
debug("rk_i2c_read: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
chip, reg, r_len, b_len);
@ -184,15 +185,26 @@ static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
while (bytes_remain_len) {
if (bytes_remain_len > RK_I2C_FIFO_SIZE) {
con = I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TRX);
con = I2C_CON_EN;
bytes_xferred = 32;
} else {
con = I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TRX) |
I2C_CON_LASTACK;
/*
* The hw can read up to 32 bytes at a time. If we need
* more than one chunk, send an ACK after the last byte.
*/
con = I2C_CON_EN | I2C_CON_LASTACK;
bytes_xferred = bytes_remain_len;
}
words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
/*
* make sure we are in plain RX mode if we read a second chunk
*/
if (snd_chunk)
con |= I2C_CON_MOD(I2C_MODE_RX);
else
con |= I2C_CON_MOD(I2C_MODE_TRX);
writel(con, &regs->con);
writel(bytes_xferred, &regs->mrxcnt);
writel(I2C_MBRFIEN | I2C_NAKRCVIEN, &regs->ien);
@ -227,6 +239,7 @@ static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
}
bytes_remain_len -= bytes_xferred;
snd_chunk = true;
debug("I2C Read bytes_remain_len %d\n", bytes_remain_len);
}