linux-kernel - Re: [PATCH 1/4] i2c: mediatek: Add apdma sync in i2c driver

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Date:   Thu, 23 Jul 2020 14:01:12 +0800
From:   Qii Wang <qii.wang@...iatek.com>
To:     Yingjoe Chen <yingjoe.chen@...iatek.com>
CC:     <wsa@...-dreams.de>, <qiangming.xia@...iatek.com>,
        <devicetree@...r.kernel.org>, <srv_heupstream@...iatek.com>,
        <leilk.liu@...iatek.com>, <linux-kernel@...r.kernel.org>,
        <robh+dt@...nel.org>, <linux-mediatek@...ts.infradead.org>,
        <linux-i2c@...r.kernel.org>, <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 1/4] i2c: mediatek: Add apdma sync in i2c driver

On Thu, 2020-07-23 at 09:29 +0800, Yingjoe Chen wrote:
> On Wed, 2020-07-22 at 20:31 +0800, Qii Wang wrote:
> > With the apdma remove hand-shake signal, it need to keep i2c and
> > apdma in sync manually.
> > 
> 
> Looks good to me,
> 
> Reviewed-by: Yingjoe Chen <yingjoe.chen@...iatek.com>
> 
> 
> Just a reminder, we have another patch 'i2c: mediatek: Add to support
> continuous mode' under review now. Please remember to update OFFSET_CON
> access code in that patch.
> 
> Joe.C
> 
> 

I and Qiangming are looking at whether the original multi-write code can
cover it, After confirming again, then we will decide whether it need to
send that patch. Thanks for your comments.

> 
> > Signed-off-by: Qii Wang <qii.wang@...iatek.com>
> > ---
> >  drivers/i2c/busses/i2c-mt65xx.c | 23 ++++++++++++++++++++---
> >  1 file changed, 20 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> > index deef69e..e6b984a 100644
> > --- a/drivers/i2c/busses/i2c-mt65xx.c
> > +++ b/drivers/i2c/busses/i2c-mt65xx.c
> > @@ -48,6 +48,9 @@
> >  
> >  #define I2C_DMA_CON_TX			0x0000
> >  #define I2C_DMA_CON_RX			0x0001
> > +#define I2C_DMA_ASYNC_MODE		0x0004
> > +#define I2C_DMA_SKIP_CONFIG		0x0010
> > +#define I2C_DMA_DIR_CHANGE		0x0200
> >  #define I2C_DMA_START_EN		0x0001
> >  #define I2C_DMA_INT_FLAG_NONE		0x0000
> >  #define I2C_DMA_CLR_FLAG		0x0000
> > @@ -205,6 +208,7 @@ struct mtk_i2c_compatible {
> >  	unsigned char timing_adjust: 1;
> >  	unsigned char dma_sync: 1;
> >  	unsigned char ltiming_adjust: 1;
> > +	unsigned char apdma_sync: 1;
> >  };
> >  
> >  struct mtk_i2c_ac_timing {
> > @@ -311,6 +315,7 @@ struct i2c_spec_values {
> >  	.timing_adjust = 1,
> >  	.dma_sync = 0,
> >  	.ltiming_adjust = 0,
> > +	.apdma_sync = 0,
> >  };
> >  
> >  static const struct mtk_i2c_compatible mt6577_compat = {
> > @@ -324,6 +329,7 @@ struct i2c_spec_values {
> >  	.timing_adjust = 0,
> >  	.dma_sync = 0,
> >  	.ltiming_adjust = 0,
> > +	.apdma_sync = 0,
> >  };
> >  
> >  static const struct mtk_i2c_compatible mt6589_compat = {
> > @@ -337,6 +343,7 @@ struct i2c_spec_values {
> >  	.timing_adjust = 0,
> >  	.dma_sync = 0,
> >  	.ltiming_adjust = 0,
> > +	.apdma_sync = 0,
> >  };
> >  
> >  static const struct mtk_i2c_compatible mt7622_compat = {
> > @@ -350,6 +357,7 @@ struct i2c_spec_values {
> >  	.timing_adjust = 0,
> >  	.dma_sync = 0,
> >  	.ltiming_adjust = 0,
> > +	.apdma_sync = 0,
> >  };
> >  
> >  static const struct mtk_i2c_compatible mt8173_compat = {
> > @@ -362,6 +370,7 @@ struct i2c_spec_values {
> >  	.timing_adjust = 0,
> >  	.dma_sync = 0,
> >  	.ltiming_adjust = 0,
> > +	.apdma_sync = 0,
> >  };
> >  
> >  static const struct mtk_i2c_compatible mt8183_compat = {
> > @@ -375,6 +384,7 @@ struct i2c_spec_values {
> >  	.timing_adjust = 1,
> >  	.dma_sync = 1,
> >  	.ltiming_adjust = 1,
> > +	.apdma_sync = 0,
> >  };
> >  
> >  static const struct of_device_id mtk_i2c_of_match[] = {
> > @@ -798,6 +808,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
> >  	u16 start_reg;
> >  	u16 control_reg;
> >  	u16 restart_flag = 0;
> > +	u16 dma_sync = 0;
> >  	u32 reg_4g_mode;
> >  	u8 *dma_rd_buf = NULL;
> >  	u8 *dma_wr_buf = NULL;
> > @@ -851,10 +862,16 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
> >  		mtk_i2c_writew(i2c, num, OFFSET_TRANSAC_LEN);
> >  	}
> >  
> > +	if (i2c->dev_comp->apdma_sync) {
> > +		dma_sync = I2C_DMA_SKIP_CONFIG | I2C_DMA_ASYNC_MODE;
> > +		if (i2c->op == I2C_MASTER_WRRD)
> > +			dma_sync |= I2C_DMA_DIR_CHANGE;
> > +	}
> > +
> >  	/* Prepare buffer data to start transfer */
> >  	if (i2c->op == I2C_MASTER_RD) {
> >  		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
> > -		writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);
> > +		writel(I2C_DMA_CON_RX | dma_sync, i2c->pdmabase + OFFSET_CON);
> >  
> >  		dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
> >  		if (!dma_rd_buf)
> > @@ -877,7 +894,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
> >  		writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
> >  	} else if (i2c->op == I2C_MASTER_WR) {
> >  		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
> > -		writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);
> > +		writel(I2C_DMA_CON_TX | dma_sync, i2c->pdmabase + OFFSET_CON);
> >  
> >  		dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
> >  		if (!dma_wr_buf)
> > @@ -900,7 +917,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
> >  		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
> >  	} else {
> >  		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
> > -		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);
> > +		writel(I2C_DMA_CLR_FLAG | dma_sync, i2c->pdmabase + OFFSET_CON);
> >  
> >  		dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
> >  		if (!dma_wr_buf)
> 
>