Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752855AbaB0Mzv (ORCPT ); Thu, 27 Feb 2014 07:55:51 -0500 Received: from va3ehsobe006.messaging.microsoft.com ([216.32.180.16]:41667 "EHLO va3outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752596AbaB0Mzt (ORCPT ); Thu, 27 Feb 2014 07:55:49 -0500 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -2 X-BigFish: VS-2(zz98dIe0eah1432Izz1f42h2148h208ch1ee6h1de0h1fdah2073h2146h1202h1e76h2189h1d1ah1d2ah21bch1fc6hzz1de098h8275bh1de097hz2dh87h2a8h839h944hd25hf0ah1220h1288h12a5h12a9h12bdh137ah13b6h1441h1504h1537h153bh162dh1631h1758h18e1h1946h19b5h1ad9h1b0ah1b2fh2222h224fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1fe8h1ff5h209eh2216h22d0h2336h2438h2461h2487h24d7h2516h2545h255eh25cch1151h1155h) X-FB-DOMAIN-IP-MATCH: fail Date: Thu, 27 Feb 2014 20:55:45 +0800 From: Shawn Guo To: Yuan Yao CC: , , , , , Fugang Duan , Subject: Re: [PATCH 1/3] i2c: add DMA support for freescale i2c driver Message-ID: <20140227125543.GF13537@S2101-09.ap.freescale.net> References: <1393481115-22136-1-git-send-email-yao.yuan@freescale.com> <1393481115-22136-2-git-send-email-yao.yuan@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1393481115-22136-2-git-send-email-yao.yuan@freescale.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: sigmatel.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% X-FOPE-CONNECTOR: Id%0$Dn%FREESCALE.MAIL.ONMICROSOFT.COM$RO%1$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 27, 2014 at 02:05:14PM +0800, Yuan Yao wrote: > Add dma support for i2c. This function depend on DMA driver. > You can turn on it by write both the dmas and dma-name properties in dts node. > And you should set ".has_dma_support" as true for dma support in imx_i2c_hwdata struct. > > Signed-off-by: Yuan Yao Just added a few people who might be interested. Shawn > --- > drivers/i2c/busses/i2c-imx.c | 358 +++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 344 insertions(+), 14 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index db895fb..6ec392b 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -37,22 +37,27 @@ > /** Includes ******************************************************************* > *******************************************************************************/ > > -#include > -#include > -#include > +#include > +#include > +#include > +#include > +#include > +#include > #include > #include > #include > -#include > #include > +#include > #include > -#include > -#include > -#include > -#include > +#include > +#include > #include > #include > +#include > #include > +#include > +#include > +#include > > /** Defines ******************************************************************** > *******************************************************************************/ > @@ -63,6 +68,9 @@ > /* Default value */ > #define IMX_I2C_BIT_RATE 100000 /* 100kHz */ > > +/* enable DMA if transfer size is bigger than this threshold */ > +#define IMX_I2C_DMA_THRESHOLD 16 > + > /* IMX I2C registers: > * the I2C register offset is different between SoCs, > * to provid support for all these chips, split the > @@ -88,6 +96,7 @@ > #define I2SR_IBB 0x20 > #define I2SR_IAAS 0x40 > #define I2SR_ICF 0x80 > +#define I2CR_DMAEN 0x02 > #define I2CR_RSTA 0x04 > #define I2CR_TXAK 0x08 > #define I2CR_MTX 0x10 > @@ -172,6 +181,17 @@ struct imx_i2c_hwdata { > unsigned ndivs; > unsigned i2sr_clr_opcode; > unsigned i2cr_ien_opcode; > + bool has_dma_support; > +}; > + > +struct imx_i2c_dma { > + struct dma_chan *chan_tx; > + struct dma_chan *chan_rx; > + dma_addr_t buf_tx; > + dma_addr_t buf_rx; > + unsigned int len_tx; > + unsigned int len_rx; > + struct completion cmd_complete; > }; > > struct imx_i2c_struct { > @@ -184,6 +204,9 @@ struct imx_i2c_struct { > int stopped; > unsigned int ifdr; /* IMX_I2C_IFDR */ > const struct imx_i2c_hwdata *hwdata; > + > + bool use_dma; > + struct imx_i2c_dma *dma; > }; > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > @@ -193,6 +216,7 @@ static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > .ndivs = ARRAY_SIZE(imx_i2c_clk_div), > .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, > .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, > + .has_dma_support = false, > > }; > > @@ -203,6 +227,7 @@ static const struct imx_i2c_hwdata imx21_i2c_hwdata = { > .ndivs = ARRAY_SIZE(imx_i2c_clk_div), > .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, > .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, > + .has_dma_support = false, > > }; > > @@ -213,6 +238,7 @@ static struct imx_i2c_hwdata vf610_i2c_hwdata = { > .ndivs = ARRAY_SIZE(vf610_i2c_clk_div), > .i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C, > .i2cr_ien_opcode = I2CR_IEN_OPCODE_0, > + .has_dma_support = true, > > }; > > @@ -254,6 +280,155 @@ static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx, > return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); > } > > +/** Functions for DMA support ************************************************ > +******************************************************************************/ > +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, u32 phy_addr) > +{ > + struct imx_i2c_dma *dma = i2c_imx->dma; > + struct dma_slave_config dma_sconfig; > + int ret; > + > + dma->chan_tx = dma_request_slave_channel(&i2c_imx->adapter.dev, "tx"); > + if (!dma->chan_tx) { > + dev_err(&i2c_imx->adapter.dev, > + "Dma tx channel request failed!\n"); > + return -ENODEV; > + } > + > + dma_sconfig.dst_addr = (dma_addr_t)phy_addr + > + (IMX_I2C_I2DR << i2c_imx->hwdata->regshift); > + dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; > + dma_sconfig.dst_maxburst = 1; > + dma_sconfig.direction = DMA_MEM_TO_DEV; > + ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig); > + if (ret < 0) { > + dev_err(&i2c_imx->adapter.dev, > + "Dma slave config failed, err = %d\n", ret); > + dma_release_channel(dma->chan_tx); > + return ret; > + } > + > + dma->chan_rx = dma_request_slave_channel(&i2c_imx->adapter.dev, "rx"); > + if (!dma->chan_rx) { > + dev_err(&i2c_imx->adapter.dev, > + "Dma rx channel request failed!\n"); > + return -ENODEV; > + } > + > + dma_sconfig.src_addr = (dma_addr_t)phy_addr + > + (IMX_I2C_I2DR << i2c_imx->hwdata->regshift); > + dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; > + dma_sconfig.src_maxburst = 1; > + dma_sconfig.direction = DMA_DEV_TO_MEM; > + ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig); > + if (ret < 0) { > + dev_err(&i2c_imx->adapter.dev, > + "Dma slave config failed, err = %d\n", ret); > + dma_release_channel(dma->chan_rx); > + return ret; > + } > + > + init_completion(&dma->cmd_complete); > + > + return 0; > +} > + > +static void i2c_imx_dma_tx_callback(void *arg) > +{ > + struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg; > + struct imx_i2c_dma *dma = i2c_imx->dma; > + > + dma_unmap_single(dma->chan_tx->device->dev, dma->buf_tx, > + dma->len_tx, DMA_TO_DEVICE); > + complete(&dma->cmd_complete); > +} > + > +static int i2c_imx_dma_tx(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) > +{ > + struct imx_i2c_dma *dma = i2c_imx->dma; > + struct dma_async_tx_descriptor *txdesc; > + > + dma->len_tx = msgs->len-1; > + dma->buf_tx = dma_map_single(dma->chan_tx->device->dev, msgs->buf, > + dma->len_tx, DMA_TO_DEVICE); > + if (dma_mapping_error(dma->chan_tx->device->dev, dma->buf_tx)) { > + dev_err(&i2c_imx->adapter.dev, "dma_map_single tx failed\n"); > + return -EINVAL; > + } > + > + txdesc = dmaengine_prep_slave_single(dma->chan_tx, dma->buf_tx, > + dma->len_tx, DMA_MEM_TO_DEV, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > + if (!txdesc) { > + dev_err(&i2c_imx->adapter.dev, > + "Not able to get desc for tx\n"); > + return -EINVAL; > + } > + > + txdesc->callback = i2c_imx_dma_tx_callback; > + txdesc->callback_param = i2c_imx; > + dmaengine_submit(txdesc); > + dma_async_issue_pending(dma->chan_tx); > + > + return 0; > +} > + > +static void i2c_imx_dma_rx_callback(void *arg) > +{ > + struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg; > + struct imx_i2c_dma *dma = i2c_imx->dma; > + > + dma_unmap_single(dma->chan_rx->device->dev, dma->buf_rx, > + dma->len_rx, DMA_FROM_DEVICE); > + complete(&dma->cmd_complete); > +} > + > +static int i2c_imx_dma_rx(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) > +{ > + struct imx_i2c_dma *dma = i2c_imx->dma; > + struct dma_async_tx_descriptor *txdesc; > + > + dma->len_rx = msgs->len - 2; > + dma->buf_rx = dma_map_single(dma->chan_rx->device->dev, msgs->buf, > + dma->len_rx, DMA_FROM_DEVICE); > + if (dma_mapping_error(dma->chan_rx->device->dev, dma->buf_rx)) { > + dev_err(&i2c_imx->adapter.dev, "dma_map_single tx failed\n"); > + return -EINVAL; > + } > + > + txdesc = dmaengine_prep_slave_single(dma->chan_rx, dma->buf_rx, > + dma->len_rx, DMA_DEV_TO_MEM, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > + if (!txdesc) { > + dev_err(&i2c_imx->adapter.dev, > + "Not able to get desc for rx\n"); > + return -EINVAL; > + } > + > + txdesc->callback = i2c_imx_dma_rx_callback; > + txdesc->callback_param = i2c_imx; > + dmaengine_submit(txdesc); > + dma_async_issue_pending(dma->chan_rx); > + > + return 0; > +} > +static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx) > +{ > + struct imx_i2c_dma *dma = i2c_imx->dma; > + struct dma_chan *dma_chan; > + > + dma_chan = dma->chan_tx; > + dma->chan_tx = NULL; > + dma->buf_tx = 0; > + dma->len_tx = 0; > + dma_release_channel(dma_chan); > + > + dma_chan = dma->chan_rx; > + dma->chan_tx = NULL; > + dma->buf_rx = 0; > + dma->len_rx = 0; > + dma_release_channel(dma_chan); > +} > /** Functions for IMX I2C adapter driver *************************************** > *******************************************************************************/ > > @@ -425,7 +600,8 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) > return IRQ_NONE; > } > > -static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) > +static int i2c_imx_pio_write(struct imx_i2c_struct *i2c_imx, > + struct i2c_msg *msgs) > { > int i, result; > > @@ -458,7 +634,56 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) > return 0; > } > > -static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) > +static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, > + struct i2c_msg *msgs) > +{ > + int result, timeout=1000; > + unsigned int temp = 0; > + > + reinit_completion(&i2c_imx->dma->cmd_complete); > + result = i2c_imx_dma_tx(i2c_imx, msgs); > + if(result) > + return result; > + > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp |= I2CR_DMAEN; > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + > + /* write slave address */ > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR); > + result = wait_for_completion_interruptible_timeout( > + &i2c_imx->dma->cmd_complete, > + msecs_to_jiffies(1000)); > + if (result == 0) > + return -ETIMEDOUT; > + > + /* waiting for Transfer complete. */ > + while(timeout--) { > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > + if (temp & 0x80) > + break; > + udelay(10); > + } > + > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp &= ~I2CR_DMAEN; > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + > + /* write the last byte */ > + imx_i2c_write_reg(msgs->buf[msgs->len-1], i2c_imx, IMX_I2C_I2DR); > + result = i2c_imx_trx_complete(i2c_imx); > + if (result) > + return result; > + > + result = i2c_imx_acked(i2c_imx); > + if (result) > + return result; > + > + return 0; > +} > + > +static int i2c_imx_pio_read(struct imx_i2c_struct *i2c_imx, > + struct i2c_msg *msgs) > { > int i, result; > unsigned int temp; > @@ -518,6 +743,80 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) > return 0; > } > > +static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, > + struct i2c_msg *msgs) > +{ > + int result, timeout=1000; > + unsigned int temp; > + > + /* write slave address */ > + imx_i2c_write_reg((msgs->addr << 1) | 0x01, i2c_imx, IMX_I2C_I2DR); > + result = i2c_imx_trx_complete(i2c_imx); > + if (result) > + return result; > + > + result = i2c_imx_acked(i2c_imx); > + if (result) > + return result; > + > + /* setup bus to read data */ > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp &= ~I2CR_MTX; > + if (msgs->len - 1) > + temp &= ~I2CR_TXAK; > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ > + > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp |= I2CR_DMAEN; > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + > + reinit_completion(&i2c_imx->dma->cmd_complete); > + result = i2c_imx_dma_rx(i2c_imx, msgs); > + if(result) > + return result; > + > + result = wait_for_completion_interruptible_timeout( > + &i2c_imx->dma->cmd_complete, > + msecs_to_jiffies(1000)); > + if (result == 0) > + return -ETIMEDOUT; > + > + /* waiting for Transfer complete. */ > + while(timeout--) { > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > + if (temp & 0x80) > + break; > + udelay(10); > + } > + > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp &= ~I2CR_DMAEN; > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + > + /* read n-1 byte data */ > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp |= I2CR_TXAK; > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + > + msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + /* read n byte data */ > + result = i2c_imx_trx_complete(i2c_imx); > + if (result) > + return result; > + > + /* It must generate STOP before read I2DR to prevent > + controller from generating another clock cycle */ > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + temp &= ~(I2CR_MSTA | I2CR_MTX); > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); > + i2c_imx_bus_busy(i2c_imx, 0); > + i2c_imx->stopped = 1; > + msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + > + return 0; > +} > + > static int i2c_imx_xfer(struct i2c_adapter *adapter, > struct i2c_msg *msgs, int num) > { > @@ -563,10 +862,18 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, > (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0), > (temp & I2SR_RXAK ? 1 : 0)); > #endif > - if (msgs[i].flags & I2C_M_RD) > - result = i2c_imx_read(i2c_imx, &msgs[i]); > - else > - result = i2c_imx_write(i2c_imx, &msgs[i]); > + if(i2c_imx->use_dma && msgs[i].len >= IMX_I2C_DMA_THRESHOLD) { > + if (msgs[i].flags & I2C_M_RD) > + result = i2c_imx_dma_read(i2c_imx, &msgs[i]); > + else > + result = i2c_imx_dma_write(i2c_imx, &msgs[i]); > + } else { > + if (msgs[i].flags & I2C_M_RD) > + result = i2c_imx_pio_read(i2c_imx, &msgs[i]); > + else > + result = i2c_imx_pio_write(i2c_imx, &msgs[i]); > + } > + > if (result) > goto fail0; > } > @@ -601,6 +908,7 @@ static int i2c_imx_probe(struct platform_device *pdev) > void __iomem *base; > int irq, ret; > u32 bitrate; > + u32 phy_addr; > > dev_dbg(&pdev->dev, "<%s>\n", __func__); > > @@ -611,6 +919,7 @@ static int i2c_imx_probe(struct platform_device *pdev) > } > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + phy_addr = res->start; > base = devm_ioremap_resource(&pdev->dev, res); > if (IS_ERR(base)) > return PTR_ERR(base); > @@ -696,6 +1005,24 @@ 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 support*/ > + if (i2c_imx->hwdata->has_dma_support) { > + dev_info(&pdev->dev, "has_dma_support_begin.\n"); > + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma), > + GFP_KERNEL); > + if (!i2c_imx->dma) { > + dev_info(&pdev->dev, "can't allocate dma struct faild use dma.\n"); > + i2c_imx->use_dma = false; > + } > + else if (i2c_imx_dma_request(i2c_imx, phy_addr)) { > + dev_info(&pdev->dev, "can't request dma chan, faild use dma.\n"); > + i2c_imx->use_dma = false; > + } > + else { > + i2c_imx->use_dma = true; > + } > + } > + > return 0; /* Return OK */ > } > > @@ -707,6 +1034,9 @@ static int i2c_imx_remove(struct platform_device *pdev) > dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); > i2c_del_adapter(&i2c_imx->adapter); > > + if (i2c_imx->use_dma) > + i2c_imx_dma_free(i2c_imx); > + > /* setup chip registers to defaults */ > imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR); > imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR); > -- > 1.8.4 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/