| Message ID | 20241125135243.1612098-1-carlos.song@nxp.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: imx: support DMA defer probing | expand |
> -----Original Message----- > From: Frank Li <frank.li@nxp.com> > Sent: Tuesday, November 26, 2024 1:17 AM > To: Carlos Song <carlos.song@nxp.com> > Cc: o.rempel@pengutronix.de; kernel@pengutronix.de; andi.shyti@kernel.org; > shawnguo@kernel.org; s.hauer@pengutronix.de; festevam@gmail.com; > linux-i2c@vger.kernel.org; imx@lists.linux.dev; > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] i2c: imx: support DMA defer probing > > On Mon, Nov 25, 2024 at 09:52:43PM +0800, carlos.song@nxp.com wrote: > > From: Carlos Song <carlos.song@nxp.com> > > > > Return -EPROBE_DEFER when dma_request_slave_channel() because DMA > > driver have not ready yet. > > wrap at 75 char. > Will fix it at V2. > > > > Move i2c_imx_dma_request() before registering I2C adapter to avoid > > infinite loop of .probe() calls to the same driver, see "e8c220fac415 > > Revert "i2c: imx: improve the error handling in i2c_imx_dma_request()"" > > and "Documentation/driver-api/driver-model/driver.rst". > > > > Use CPU mode to avoid stuck registering i2c adapter when DMA resources > > are unavailable. > > > > Signed-off-by: Carlos Song <carlos.song@nxp.com> > > Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> > > --- > > drivers/i2c/busses/i2c-imx.c | 21 +++++++++++++-------- > > 1 file changed, 13 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-imx.c > > b/drivers/i2c/busses/i2c-imx.c index 5ed4cb61e262..ee7070ee9e6e 100644 > > --- a/drivers/i2c/busses/i2c-imx.c > > +++ b/drivers/i2c/busses/i2c-imx.c > > @@ -397,17 +397,16 @@ static void i2c_imx_reset_regs(struct > > imx_i2c_struct *i2c_imx) } > > > > /* Functions for DMA support */ > > -static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, > > - dma_addr_t phy_addr) > > +static int i2c_imx_dma_request(struct device *dev, dma_addr_t > > +phy_addr) > > { > > Not sure why you change "struct imx_i2c_struct *i2c_imx" to "struct device > *dev" > Yes, you are right. I really made the redundant fixes. I just need to using this change. ... /* Functions for DMA support */ -static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, dma_addr_t phy_addr) - struct device *dev = &i2c_imx->adapter.dev; + struct device *dev = i2c_imx->adapter.dev.parent; ... I will send V2 and fix this. > > + struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev); > > struct imx_i2c_dma *dma; > > struct dma_slave_config dma_sconfig; > > - struct device *dev = &i2c_imx->adapter.dev; > > int ret; > > > > dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL); > > if (!dma) > > - return; > > + return -ENOMEM; > > > > dma->chan_tx = dma_request_chan(dev, "tx"); > > if (IS_ERR(dma->chan_tx)) { > > @@ -452,7 +451,7 @@ static void i2c_imx_dma_request(struct > imx_i2c_struct *i2c_imx, > > dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n", > > dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); > > > > - return; > > + return 0; > > > > fail_rx: > > dma_release_channel(dma->chan_rx); > > @@ -460,6 +459,8 @@ static void i2c_imx_dma_request(struct > imx_i2c_struct *i2c_imx, > > dma_release_channel(dma->chan_tx); > > fail_al: > > devm_kfree(dev, dma); > > + > > + return ret; > > } > > > > static void i2c_imx_dma_callback(void *arg) @@ -1803,6 +1804,13 @@ > > static int i2c_imx_probe(struct platform_device *pdev) > > if (ret == -EPROBE_DEFER) > > goto clk_notifier_unregister; > > > > + /* Init DMA config if supported */ > > + ret = i2c_imx_dma_request(&pdev->dev, phy_addr); > > + if (ret == -EPROBE_DEFER) { > > + dev_err(&pdev->dev, "DMA not ready, go defer probe!\n"); > > + goto clk_notifier_unregister; > > + } > > + > > /* Add I2C adapter */ > > ret = i2c_add_numbered_adapter(&i2c_imx->adapter); > > if (ret < 0) > > @@ -1817,9 +1825,6 @@ static int i2c_imx_probe(struct platform_device > *pdev) > > i2c_imx->adapter.name); > > dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n"); > > > > - /* Init DMA config if supported */ > > - i2c_imx_dma_request(i2c_imx, phy_addr); > > - > > return 0; /* Return OK */ > > > > clk_notifier_unregister: > > -- > > 2.34.1 > >
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 5ed4cb61e262..ee7070ee9e6e 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -397,17 +397,16 @@ static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx) } /* Functions for DMA support */ -static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, - dma_addr_t phy_addr) +static int i2c_imx_dma_request(struct device *dev, dma_addr_t phy_addr) { + struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev); struct imx_i2c_dma *dma; struct dma_slave_config dma_sconfig; - struct device *dev = &i2c_imx->adapter.dev; int ret; dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL); if (!dma) - return; + return -ENOMEM; dma->chan_tx = dma_request_chan(dev, "tx"); if (IS_ERR(dma->chan_tx)) { @@ -452,7 +451,7 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n", dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); - return; + return 0; fail_rx: dma_release_channel(dma->chan_rx); @@ -460,6 +459,8 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, dma_release_channel(dma->chan_tx); fail_al: devm_kfree(dev, dma); + + return ret; } static void i2c_imx_dma_callback(void *arg) @@ -1803,6 +1804,13 @@ static int i2c_imx_probe(struct platform_device *pdev) if (ret == -EPROBE_DEFER) goto clk_notifier_unregister; + /* Init DMA config if supported */ + ret = i2c_imx_dma_request(&pdev->dev, phy_addr); + if (ret == -EPROBE_DEFER) { + dev_err(&pdev->dev, "DMA not ready, go defer probe!\n"); + goto clk_notifier_unregister; + } + /* Add I2C adapter */ ret = i2c_add_numbered_adapter(&i2c_imx->adapter); if (ret < 0) @@ -1817,9 +1825,6 @@ static int i2c_imx_probe(struct platform_device *pdev) i2c_imx->adapter.name); dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n"); - /* Init DMA config if supported */ - i2c_imx_dma_request(i2c_imx, phy_addr); - return 0; /* Return OK */ clk_notifier_unregister: