On Fri, 2015-07-31 at 13:00 +0200, Wolfram Sang wrote:
> On Tue, Jul 28, 2015 at 11:38:05AM +0800, Eddie Huang wrote:
> > From: Liguo Zhang
> >
> > Reset i2c dma engine in hw init function.
> > When occur i2c ack error, mtk_i2c_irq may is twice,
> > first is the ack error interrupt, then the complete interrupt,
> > so i2c->irq_stat need keep the two interrupt value, and only
> > call complete() for the complete interrupt.
> >
> > Signed-off-by: Liguo Zhang
> > Signed-off-by: Eddie Huang
>
> Looks to me this patch needs to be split up into one patch per issue?
OK, I can split
> And doesn't it kill the auto_restart functionality? Sascha?
No. restart_flag already set in mtk_i2c_do_transfer() function.It is not
necessary check restart_flag again in mtk_i2c_irq(). It is simpler to
just read status bit and write back to clear interrupt status.
Eddie
Thanks
>
> > ---
> > drivers/i2c/busses/i2c-mt65xx.c | 25 ++---
> > 1 file changed, 18 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-mt65xx.c
> > b/drivers/i2c/busses/i2c-mt65xx.c
> > index 9920eef..57d11b7 100644
> > --- a/drivers/i2c/busses/i2c-mt65xx.c
> > +++ b/drivers/i2c/busses/i2c-mt65xx.c
> > @@ -59,6 +59,7 @@
> > #define I2C_DMA_START_EN 0x0001
> > #define I2C_DMA_INT_FLAG_NONE 0x
> > #define I2C_DMA_CLR_FLAG 0x
> > +#define I2C_DMA_HARD_RST 0x0002
> >
> > #define I2C_DEFAULT_SPEED 10 /* hz */
> > #define MAX_FS_MODE_SPEED 40
> > @@ -81,6 +82,7 @@ enum DMA_REGS_OFFSET {
> > OFFSET_INT_FLAG = 0x0,
> > OFFSET_INT_EN = 0x04,
> > OFFSET_EN = 0x08,
> > + OFFSET_RST = 0x0c,
> > OFFSET_CON = 0x18,
> > OFFSET_TX_MEM_ADDR = 0x1c,
> > OFFSET_RX_MEM_ADDR = 0x20,
> > @@ -262,6 +264,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
> > I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
> > writew(control_reg, i2c->base + OFFSET_CONTROL);
> > writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
> > +
> > + writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
> > + udelay(50);
> > + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
> > }
> >
> > /*
> > @@ -550,16 +556,20 @@ err_exit:
> > static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
> > {
> > struct mtk_i2c *i2c = dev_id;
> > - u16 restart_flag = 0;
> > + u16 intr_stat = 0;
> >
> > - if (i2c->dev_comp->auto_restart)
> > - restart_flag = I2C_RS_TRANSFER;
> > + intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
> > + writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
> >
> > - i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
> > - writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
> > - | I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
> > + /*
> > +* when occurs i2c ack error, mtk_i2c_irq is called twice,
> > +* first is the ack error interrupt, then the complete interrupt,
> > +* i2c->irq_stat need keep the two interrupt value.
> > +*/
> > + i2c->irq_stat |= intr_stat;
> >
> > - complete(&i2c->msg_complete);
> > + if (i2c->irq_stat & I2C_TRANSAC_COMP)
> > + complete(&i2c->msg_complete);
> >
> > return IRQ_HANDLED;
> > }
> > @@ -729,3 +739,4 @@ module_platform_driver(mtk_i2c_driver);
> > MODULE_LICENSE("GPL v2");
> > MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
> > MODULE_AUTHOR("Xudong Chen ");
> > +MODULE_AUTHOR("Liguo Zhang ");
> > --
> > 1.7.9.5
> >
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