From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v3 2/8] spi: sun4i: add DMA support Date: Tue, 5 Aug 2014 22:23:54 +0200 Message-ID: <20140805202354.GA2019@lukather> References: <1407183002-29420-1-git-send-email-emilio@elopez.com.ar> <1407183002-29420-3-git-send-email-emilio@elopez.com.ar> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="45Z9DzgjV8m4Oswq" Cc: vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, sunny-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org, kevin.z.m.zh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, shuge-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org, zhuzhenhua-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org To: Emilio =?iso-8859-1?Q?L=F3pez?= Return-path: Content-Disposition: inline In-Reply-To: <1407183002-29420-3-git-send-email-emilio-0Z03zUJReD5OxF6Tv1QG9Q@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --45Z9DzgjV8m4Oswq Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Mon, Aug 04, 2014 at 05:09:56PM -0300, Emilio L=F3pez wrote: > + if (sun4i_spi_can_dma(master, spi, tfr)) { > + dev_dbg(&sspi->master->dev, "Using DMA mode for transfer\n"); > + > + if (sspi->tx_buf) { > + desc_tx =3D dmaengine_prep_slave_sg(sspi->tx_dma_chan, > + tfr->tx_sg.sgl, tfr->tx_sg.nents, > + DMA_TO_DEVICE, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > + if (!desc_tx) { > + dev_err(&sspi->master->dev, > + "Couldn't prepare dma slave\n"); > + return -EIO; > + } > + > + dmaengine_submit(desc_tx); > + } > + > + if (sspi->rx_buf) { > + desc_rx =3D dmaengine_prep_slave_sg(sspi->rx_dma_chan, > + tfr->rx_sg.sgl, tfr->rx_sg.nents, > + DMA_FROM_DEVICE, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > + if (!desc_rx) { > + dev_err(&sspi->master->dev, > + "Couldn't prepare dma slave\n"); > + return -EIO; > + } > + > + dmaengine_submit(desc_rx); > + } > + > + /* Enable DMA requests */ > + reg =3D sun4i_spi_read(sspi, SUN4I_CTL_REG); > + sun4i_spi_write(sspi, SUN4I_CTL_REG, > + reg | SUN4I_CTL_DMAMC_DEDICATED); > + sun4i_spi_write(sspi, SUN4I_DMA_CTL_REG, > + SUN4I_DMA_CTL_TF_NOT_FULL | > + SUN4I_DMA_CTL_RF_READY); > + > + dma_async_issue_pending(sspi->rx_dma_chan); > + dma_async_issue_pending(sspi->tx_dma_chan); I guess the DMA levels setup and the issue pending calls could be moved to the if statements above about wether the RX and TX buffers are here or not. > + } else { > + dev_dbg(&sspi->master->dev, "Using PIO mode for transfer\n"); > + > + /* Disable DMA requests */ > + reg =3D sun4i_spi_read(sspi, SUN4I_CTL_REG); > + sun4i_spi_write(sspi, SUN4I_CTL_REG, > + reg & ~SUN4I_CTL_DMAMC_DEDICATED); > + sun4i_spi_write(sspi, SUN4I_DMA_CTL_REG, 0); > + > + /* Fill the TX FIFO */ > + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH); > + } > + > /* Start the transfer */ > reg =3D sun4i_spi_read(sspi, SUN4I_CTL_REG); > sun4i_spi_write(sspi, SUN4I_CTL_REG, reg | SUN4I_CTL_XCH); > @@ -286,7 +359,12 @@ static int sun4i_spi_transfer_one(struct spi_master = *master, > goto out; > } > =20 > - sun4i_spi_drain_fifo(sspi, SUN4I_FIFO_DEPTH); > + if (sun4i_spi_can_dma(master, spi, tfr) && desc_rx) { > + /* The receive transfer should be the last one to finish */ > + dma_wait_for_async_tx(desc_rx); > + } else { > + sun4i_spi_drain_fifo(sspi, SUN4I_FIFO_DEPTH); > + } > =20 > out: > sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, 0); > @@ -351,6 +429,7 @@ static int sun4i_spi_runtime_suspend(struct device *d= ev) > =20 > static int sun4i_spi_probe(struct platform_device *pdev) > { > + struct dma_slave_config dma_sconfig; > struct spi_master *master; > struct sun4i_spi *sspi; > struct resource *res; > @@ -386,7 +465,10 @@ static int sun4i_spi_probe(struct platform_device *p= dev) > goto err_free_master; > } > =20 > + init_completion(&sspi->done); > sspi->master =3D master; > + master->can_dma =3D sun4i_spi_can_dma; > + master->prepare_message =3D sun4i_spi_prepare_message; > master->set_cs =3D sun4i_spi_set_cs; > master->transfer_one =3D sun4i_spi_transfer_one; > master->num_chipselect =3D 4; > @@ -409,7 +491,45 @@ static int sun4i_spi_probe(struct platform_device *p= dev) > goto err_free_master; > } > =20 > - init_completion(&sspi->done); > + sspi->tx_dma_chan =3D dma_request_slave_channel_reason(&pdev->dev, "tx"= ); > + if (IS_ERR(sspi->tx_dma_chan)) { > + dev_err(&pdev->dev, "Unable to acquire DMA channel TX\n"); > + ret =3D PTR_ERR(sspi->tx_dma_chan); > + goto err_free_master; > + } > + > + dma_sconfig.direction =3D DMA_MEM_TO_DEV; > + dma_sconfig.src_addr_width =3D DMA_SLAVE_BUSWIDTH_1_BYTE; > + dma_sconfig.dst_addr_width =3D DMA_SLAVE_BUSWIDTH_1_BYTE; > + dma_sconfig.dst_addr =3D res->start + SUN4I_TXDATA_REG; > + dma_sconfig.src_maxburst =3D 1; > + dma_sconfig.dst_maxburst =3D 1; > + > + ret =3D dmaengine_slave_config(sspi->tx_dma_chan, &dma_sconfig); > + if (ret) { > + dev_err(&pdev->dev, "Unable to configure TX DMA slave\n"); > + goto err_tx_dma_release; > + } > + > + sspi->rx_dma_chan =3D dma_request_slave_channel_reason(&pdev->dev, "rx"= ); > + if (IS_ERR(sspi->rx_dma_chan)) { > + dev_err(&pdev->dev, "Unable to acquire DMA channel RX\n"); > + ret =3D PTR_ERR(sspi->rx_dma_chan); > + goto err_tx_dma_release; > + } > + > + dma_sconfig.direction =3D DMA_DEV_TO_MEM; > + dma_sconfig.src_addr_width =3D DMA_SLAVE_BUSWIDTH_1_BYTE; > + dma_sconfig.dst_addr_width =3D DMA_SLAVE_BUSWIDTH_1_BYTE; > + dma_sconfig.src_addr =3D res->start + SUN4I_RXDATA_REG; > + dma_sconfig.src_maxburst =3D 1; > + dma_sconfig.dst_maxburst =3D 1; > + > + ret =3D dmaengine_slave_config(sspi->rx_dma_chan, &dma_sconfig); > + if (ret) { > + dev_err(&pdev->dev, "Unable to configure RX DMA slave\n"); > + goto err_rx_dma_release; > + } > =20 > /* > * This wake-up/shutdown pattern is to be able to have the > @@ -418,7 +538,7 @@ static int sun4i_spi_probe(struct platform_device *pd= ev) > ret =3D sun4i_spi_runtime_resume(&pdev->dev); > if (ret) { > dev_err(&pdev->dev, "Couldn't resume the device\n"); > - goto err_free_master; > + goto err_rx_dma_release; > } > =20 > pm_runtime_set_active(&pdev->dev); > @@ -436,6 +556,10 @@ static int sun4i_spi_probe(struct platform_device *p= dev) > err_pm_disable: > pm_runtime_disable(&pdev->dev); > sun4i_spi_runtime_suspend(&pdev->dev); > +err_rx_dma_release: > + dma_release_channel(sspi->rx_dma_chan); > +err_tx_dma_release: > + dma_release_channel(sspi->tx_dma_chan); > err_free_master: > spi_master_put(master); > return ret; > @@ -443,8 +567,17 @@ err_free_master: > =20 > static int sun4i_spi_remove(struct platform_device *pdev) > { > + struct spi_master *master =3D platform_get_drvdata(pdev); > + struct sun4i_spi *sspi =3D spi_master_get_devdata(master); > + > + if (pm_runtime_active(&pdev->dev)) > + sun4i_spi_runtime_suspend(&pdev->dev); > + This doesn't really belong in this patch, please send a separate one. Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --45Z9DzgjV8m4Oswq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJT4T1aAAoJEBx+YmzsjxAgTD0P+gMu4PJaaW8NdbrN6Sl5/TWr NVUaO9zeZ7AMK074HNh6C4+L13D8Q5IVU+CMaqVCMlVXx5U1/6Djtckd+0Mw1jiZ 7fFpOTOXAB2i7RK/m0EJZmBB1vLGln0kaFpnFSALw83ftC/h6UCZbO2eMo9aL632 J8GERcsxvM/zz78tafaegaXpy5+fEM4+3+MKbtcFm9wA91dkO36Qvs97w5vA87Dy bQcIC+KsPlbRpg6loDtgFNCMpTaJI8NsWtOBY3zuTUrehAn0CYDnYeMOnBnm4BsT rPno4hhXiJPM8oApadJBvgEQeMNWPmextCd/UNw8+PB59PrAe5vciH5d6JG2biTa GMKGvrHPOoOKj1ejr49wSIUuCZ9jReZmnsbAq8YT3287IS3TO/6Sk/EFUyFlksFr efjzSrm8AfBpXcU+rSaKhitkK8lXysTe93uk8zLekehKAVatCIHtW0gMKS7YOF6m te4RbvKtDBsvge1L5wOoMciYzOiYVY7hcdHTYcwsTnXn9sL6942tvg6LobCA66bN t9G2+Cm4wXPQXRWMICbjWfLjEb/Q1BiDpJv2rmC6pK78zGyaKa0bCh+HxgLgTDxG CarQ95ufNmYOjXmBFjGr9xqqA+nl7Jb3BFuUw89DA48PQN9s99LtJKlofl2ZiqDL YUhbvUa+XGMSM8LRewey =iyqx -----END PGP SIGNATURE----- --45Z9DzgjV8m4Oswq-- -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html