From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Brugger Subject: Re: [PATCH RESEND v6 3/6] i2c: mediatek: Add arb clock in i2c driver Date: Fri, 12 Apr 2019 20:41:51 +0200 Message-ID: <9a4fafcc-07aa-914a-c57e-ebe647650d35@gmail.com> References: <1554208560-14817-1-git-send-email-qii.wang@mediatek.com> <1554208560-14817-4-git-send-email-qii.wang@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1554208560-14817-4-git-send-email-qii.wang@mediatek.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Qii Wang , wsa@the-dreams.de Cc: devicetree@vger.kernel.org, srv_heupstream@mediatek.com, robh@kernel.org, leilk.liu@mediatek.com, xinping.qian@mediatek.com, linux-kernel@vger.kernel.org, liguo.zhang@mediatek.com, linux-mediatek@lists.infradead.org, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On 02/04/2019 14:35, Qii Wang wrote: > When two i2c controllers are internally connected to the same > GPIO pins, the arb clock is needed to ensure that the waveforms > do not interfere with each other. And we also need to enable > the interrupt to find arb lost, old i2c controllers also have > the bit. > > Signed-off-by: Qii Wang > Reviewed-by: Nicolas Boichat > --- > drivers/i2c/busses/i2c-mt65xx.c | 25 ++++++++++++++++++++++--- > 1 file changed, 22 insertions(+), 3 deletions(-) Looks good: Reviewed-by: Matthias Brugger > > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c > index be36018..1a7235e 100644 > --- a/drivers/i2c/busses/i2c-mt65xx.c > +++ b/drivers/i2c/busses/i2c-mt65xx.c > @@ -35,6 +35,7 @@ > #include > > #define I2C_RS_TRANSFER (1 << 4) > +#define I2C_ARB_LOST (1 << 3) > #define I2C_HS_NACKERR (1 << 2) > #define I2C_ACKERR (1 << 1) > #define I2C_TRANSAC_COMP (1 << 0) > @@ -181,6 +182,7 @@ struct mtk_i2c { > struct clk *clk_main; /* main clock for i2c bus */ > struct clk *clk_dma; /* DMA clock for i2c via DMA */ > struct clk *clk_pmic; /* PMIC clock for i2c from PMIC */ > + struct clk *clk_arb; /* Arbitrator clock for i2c */ > bool have_pmic; /* can use i2c pins from PMIC */ > bool use_push_pull; /* IO config push-pull mode */ > > @@ -299,8 +301,18 @@ static int mtk_i2c_clock_enable(struct mtk_i2c *i2c) > if (ret) > goto err_pmic; > } > + > + if (i2c->clk_arb) { > + ret = clk_prepare_enable(i2c->clk_arb); > + if (ret) > + goto err_arb; > + } > + > return 0; > > +err_arb: > + if (i2c->have_pmic) > + clk_disable_unprepare(i2c->clk_pmic); > err_pmic: > clk_disable_unprepare(i2c->clk_main); > err_main: > @@ -311,6 +323,9 @@ static int mtk_i2c_clock_enable(struct mtk_i2c *i2c) > > static void mtk_i2c_clock_disable(struct mtk_i2c *i2c) > { > + if (i2c->clk_arb) > + clk_disable_unprepare(i2c->clk_arb); > + > if (i2c->have_pmic) > clk_disable_unprepare(i2c->clk_pmic); > > @@ -519,13 +534,13 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, > > /* Clear interrupt status */ > mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR | > - I2C_TRANSAC_COMP, OFFSET_INTR_STAT); > + I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_STAT); > > mtk_i2c_writew(i2c, I2C_FIFO_ADDR_CLR, OFFSET_FIFO_ADDR_CLR); > > /* Enable interrupt */ > mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR | > - I2C_TRANSAC_COMP, OFFSET_INTR_MASK); > + I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_MASK); > > /* Set transfer and transaction len */ > if (i2c->op == I2C_MASTER_WRRD) { > @@ -659,7 +674,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, > > /* Clear interrupt mask */ > mtk_i2c_writew(i2c, ~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | > - I2C_TRANSAC_COMP), OFFSET_INTR_MASK); > + I2C_ARB_LOST | I2C_TRANSAC_COMP), OFFSET_INTR_MASK); > > if (i2c->op == I2C_MASTER_WR) { > dma_unmap_single(i2c->dev, wpaddr, > @@ -884,6 +899,10 @@ static int mtk_i2c_probe(struct platform_device *pdev) > return PTR_ERR(i2c->clk_dma); > } > > + i2c->clk_arb = devm_clk_get(&pdev->dev, "arb"); > + if (IS_ERR(i2c->clk_arb)) > + i2c->clk_arb = NULL; > + > clk = i2c->clk_main; > if (i2c->have_pmic) { > i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic"); >