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authorLiguo Zhang <liguo.zhang@mediatek.com>2015-12-15 10:22:26 +0300
committerWolfram Sang <wsa@the-dreams.de>2016-01-03 21:38:22 +0300
commit8378d01f60a95d9205c6da47cb0cd2a594f7e07f (patch)
treee1697e1f5732be4bb47263406cff8713cc0c7bef /drivers/i2c
parente8e712916ceade419ab52900917ed568c7b3ec26 (diff)
downloadlinux-8378d01f60a95d9205c6da47cb0cd2a594f7e07f.tar.xz
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 <liguo.zhang@mediatek.com> Reviewed-by: Eddie Huang <eddie.huang@mediatek.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-mt65xx.c21
1 files changed, 19 insertions, 2 deletions
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;
}