From 8378d01f60a95d9205c6da47cb0cd2a594f7e07f Mon Sep 17 00:00:00 2001 From: Liguo Zhang Date: Tue, 15 Dec 2015 15:22:26 +0800 Subject: i2c: mediatek: fix i2c multi transfer issue in high speed mode For mt8173 platform with auto restart support, when doing i2c multi transfer in high speed, we should ignore the first restart irq after the master code, otherwise the first transfer will be discarded. Signed-off-by: Liguo Zhang Reviewed-by: Eddie Huang Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-mt65xx.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index dc4aac64ac2e..aec8e6ce38a4 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -155,6 +155,7 @@ struct mtk_i2c { u16 timing_reg; u16 high_speed_reg; unsigned char auto_restart; + bool ignore_restart_irq; const struct mtk_i2c_compatible *dev_comp; }; @@ -539,6 +540,14 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap, } } + if (i2c->auto_restart && num >= 2 && i2c->speed_hz > MAX_FS_MODE_SPEED) + /* ignore the first restart irq after the master code, + * otherwise the first transfer will be discarded. + */ + i2c->ignore_restart_irq = true; + else + i2c->ignore_restart_irq = false; + while (left_num--) { if (!msgs->buf) { dev_dbg(i2c->dev, "data buffer is NULL.\n"); @@ -592,8 +601,16 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id) * i2c->irq_stat need keep the two interrupt value. */ i2c->irq_stat |= intr_stat; - if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag)) - complete(&i2c->msg_complete); + + if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) { + i2c->ignore_restart_irq = false; + i2c->irq_stat = 0; + writew(I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG | I2C_TRANSAC_START, + i2c->base + OFFSET_START); + } else { + if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag)) + complete(&i2c->msg_complete); + } return IRQ_HANDLED; } -- cgit