From 05dcd361a2785c3fcb9c43a621da4434cf1519b4 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 12 Sep 2012 08:42:16 +0200 Subject: ARM: dts: add twi nodes for atmel SoCs Add TWI nodes for atmel SoCs but keep i2c-gpio ones in order to let the choice to the user in dts files. Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/boot/dts/at91sam9260.dtsi | 10 ++++++++++ arch/arm/boot/dts/at91sam9263.dtsi | 10 ++++++++++ arch/arm/boot/dts/at91sam9g20.dtsi | 4 ++++ arch/arm/boot/dts/at91sam9g45.dtsi | 20 ++++++++++++++++++++ arch/arm/boot/dts/at91sam9n12.dtsi | 20 ++++++++++++++++++++ arch/arm/boot/dts/at91sam9x5.dtsi | 30 ++++++++++++++++++++++++++++++ 6 files changed, 94 insertions(+) (limited to 'arch/arm/boot') diff --git a/arch/arm/boot/dts/at91sam9260.dtsi b/arch/arm/boot/dts/at91sam9260.dtsi index 66389c1c6f62..edef4521cef4 100644 --- a/arch/arm/boot/dts/at91sam9260.dtsi +++ b/arch/arm/boot/dts/at91sam9260.dtsi @@ -28,6 +28,7 @@ gpio2 = &pioC; tcb0 = &tcb0; tcb1 = &tcb1; + i2c0 = &i2c0; }; cpus { cpu@0 { @@ -199,6 +200,15 @@ status = "disabled"; }; + i2c0: i2c@fffac000 { + compatible = "atmel,at91sam9260-i2c"; + reg = <0xfffac000 0x100>; + interrupts = <11 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + adc0: adc@fffe0000 { compatible = "atmel,at91sam9260-adc"; reg = <0xfffe0000 0x100>; diff --git a/arch/arm/boot/dts/at91sam9263.dtsi b/arch/arm/boot/dts/at91sam9263.dtsi index b460d6ce9eb5..e7942c7e3f67 100644 --- a/arch/arm/boot/dts/at91sam9263.dtsi +++ b/arch/arm/boot/dts/at91sam9263.dtsi @@ -24,6 +24,7 @@ gpio3 = &pioD; gpio4 = &pioE; tcb0 = &tcb0; + i2c0 = &i2c0; }; cpus { cpu@0 { @@ -180,6 +181,15 @@ interrupts = <24 4 2>; status = "disabled"; }; + + i2c0: i2c@fff88000 { + compatible = "atmel,at91sam9263-i2c"; + reg = <0xfff88000 0x100>; + interrupts = <13 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; }; nand0: nand@40000000 { diff --git a/arch/arm/boot/dts/at91sam9g20.dtsi b/arch/arm/boot/dts/at91sam9g20.dtsi index 2a1d1ca8bd86..75ce6e760016 100644 --- a/arch/arm/boot/dts/at91sam9g20.dtsi +++ b/arch/arm/boot/dts/at91sam9g20.dtsi @@ -18,6 +18,10 @@ ahb { apb { + i2c0: i2c@fffac000 { + compatible = "atmel,at91sam9g20-i2c"; + }; + adc0: adc@fffe0000 { atmel,adc-startup-time = <40>; }; diff --git a/arch/arm/boot/dts/at91sam9g45.dtsi b/arch/arm/boot/dts/at91sam9g45.dtsi index bafa8806fc17..ae4bb6da2878 100644 --- a/arch/arm/boot/dts/at91sam9g45.dtsi +++ b/arch/arm/boot/dts/at91sam9g45.dtsi @@ -29,6 +29,8 @@ gpio4 = &pioE; tcb0 = &tcb0; tcb1 = &tcb1; + i2c0 = &i2c0; + i2c1 = &i2c1; }; cpus { cpu@0 { @@ -201,6 +203,24 @@ status = "disabled"; }; + i2c0: i2c@fff84000 { + compatible = "atmel,at91sam9g10-i2c"; + reg = <0xfff84000 0x100>; + interrupts = <12 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + + i2c1: i2c@fff88000 { + compatible = "atmel,at91sam9g10-i2c"; + reg = <0xfff88000 0x100>; + interrupts = <13 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + adc0: adc@fffb0000 { compatible = "atmel,at91sam9260-adc"; reg = <0xfffb0000 0x100>; diff --git a/arch/arm/boot/dts/at91sam9n12.dtsi b/arch/arm/boot/dts/at91sam9n12.dtsi index bfac0dfc332c..42e9fba44237 100644 --- a/arch/arm/boot/dts/at91sam9n12.dtsi +++ b/arch/arm/boot/dts/at91sam9n12.dtsi @@ -26,6 +26,8 @@ gpio3 = &pioD; tcb0 = &tcb0; tcb1 = &tcb1; + i2c0 = &i2c0; + i2c1 = &i2c1; }; cpus { cpu@0 { @@ -178,6 +180,24 @@ atmel,use-dma-tx; status = "disabled"; }; + + i2c0: i2c@f8010000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8010000 0x100>; + interrupts = <9 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + + i2c1: i2c@f8014000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8014000 0x100>; + interrupts = <10 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; }; nand0: nand@40000000 { diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi index 4a18c393b136..e05afbc3e047 100644 --- a/arch/arm/boot/dts/at91sam9x5.dtsi +++ b/arch/arm/boot/dts/at91sam9x5.dtsi @@ -27,6 +27,9 @@ gpio3 = &pioD; tcb0 = &tcb0; tcb1 = &tcb1; + i2c0 = &i2c0; + i2c1 = &i2c1; + i2c2 = &i2c2; }; cpus { cpu@0 { @@ -192,6 +195,33 @@ status = "disabled"; }; + i2c0: i2c@f8010000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8010000 0x100>; + interrupts = <9 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + + i2c1: i2c@f8014000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8014000 0x100>; + interrupts = <10 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + + i2c2: i2c@f8018000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8018000 0x100>; + interrupts = <11 4 6>; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + adc0: adc@f804c000 { compatible = "atmel,at91sam9260-adc"; reg = <0xf804c000 0x100>; -- cgit 1.4.1 From fbc1871511ed201504d6e5b36f13ea77e4be2907 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 12 Sep 2012 08:42:17 +0200 Subject: ARM: dts: add twi nodes for atmel boards Still use i2c-gpio on boards which have a SoC with a TWI IP which doesn't have clock stretching in transmission mode. Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/boot/dts/at91sam9g25ek.dts | 12 ++++++++++++ arch/arm/boot/dts/at91sam9m10g45ek.dts | 8 ++++++++ arch/arm/boot/dts/at91sam9n12ek.dts | 8 ++++++++ 3 files changed, 28 insertions(+) (limited to 'arch/arm/boot') diff --git a/arch/arm/boot/dts/at91sam9g25ek.dts b/arch/arm/boot/dts/at91sam9g25ek.dts index 96514c134e54..877c08f06763 100644 --- a/arch/arm/boot/dts/at91sam9g25ek.dts +++ b/arch/arm/boot/dts/at91sam9g25ek.dts @@ -32,6 +32,18 @@ phy-mode = "rmii"; status = "okay"; }; + + i2c0: i2c@f8010000 { + status = "okay"; + }; + + i2c1: i2c@f8014000 { + status = "okay"; + }; + + i2c2: i2c@f8018000 { + status = "okay"; + }; }; usb0: ohci@00600000 { diff --git a/arch/arm/boot/dts/at91sam9m10g45ek.dts b/arch/arm/boot/dts/at91sam9m10g45ek.dts index a3633bd13111..15e1dd43f625 100644 --- a/arch/arm/boot/dts/at91sam9m10g45ek.dts +++ b/arch/arm/boot/dts/at91sam9m10g45ek.dts @@ -46,6 +46,14 @@ phy-mode = "rmii"; status = "okay"; }; + + i2c0: i2c@fff84000 { + status = "okay"; + }; + + i2c1: i2c@fff88000 { + status = "okay"; + }; }; nand0: nand@40000000 { diff --git a/arch/arm/boot/dts/at91sam9n12ek.dts b/arch/arm/boot/dts/at91sam9n12ek.dts index f4e43e38f3a1..912b2c283d6f 100644 --- a/arch/arm/boot/dts/at91sam9n12ek.dts +++ b/arch/arm/boot/dts/at91sam9n12ek.dts @@ -37,6 +37,14 @@ dbgu: serial@fffff200 { status = "okay"; }; + + i2c0: i2c@f8010000 { + status = "okay"; + }; + + i2c1: i2c@f8014000 { + status = "okay"; + }; }; nand0: nand@40000000 { -- cgit 1.4.1 From 62885f59a26195d9f6a3f8c795225dfbab62a110 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Fri, 24 Aug 2012 05:44:31 +0200 Subject: MXS: Implement DMA support into mxs-i2c This patch implements DMA support into mxs-i2c. DMA transfers are now enabled via DT. The DMA operation is enabled by default. Signed-off-by: Marek Vasut Tested-by: Fabio Estevam [wsa: rebased to 3.6-rc7] Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-mxs.txt | 2 + arch/arm/boot/dts/imx28.dtsi | 2 + drivers/i2c/busses/i2c-mxs.c | 269 ++++++++++++++++++++-- 3 files changed, 251 insertions(+), 22 deletions(-) (limited to 'arch/arm/boot') diff --git a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt index 30ac3a0557f7..7a3fe9e5f4cb 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt @@ -6,6 +6,7 @@ Required properties: - interrupts: Should contain ERROR and DMA interrupts - clock-frequency: Desired I2C bus clock frequency in Hz. Only 100000Hz and 400000Hz modes are supported. +- fsl,i2c-dma-channel: APBX DMA channel for the I2C Examples: @@ -16,4 +17,5 @@ i2c0: i2c@80058000 { reg = <0x80058000 2000>; interrupts = <111 68>; clock-frequency = <100000>; + fsl,i2c-dma-channel = <6>; }; diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dtsi index 3fa6d190fab4..ba8227e92bd1 100644 --- a/arch/arm/boot/dts/imx28.dtsi +++ b/arch/arm/boot/dts/imx28.dtsi @@ -661,6 +661,7 @@ reg = <0x80058000 0x2000>; interrupts = <111 68>; clock-frequency = <100000>; + fsl,i2c-dma-channel = <6>; status = "disabled"; }; @@ -671,6 +672,7 @@ reg = <0x8005a000 0x2000>; interrupts = <110 69>; clock-frequency = <100000>; + fsl,i2c-dma-channel = <7>; status = "disabled"; }; diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 51f05b8520ed..1f58197062cf 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -7,8 +7,6 @@ * * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved. * - * TODO: add dma-support if platform-support for it is available - * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -31,9 +29,16 @@ #include #include #include +#include +#include +#include #define DRIVER_NAME "mxs-i2c" +static bool use_pioqueue; +module_param(use_pioqueue, bool, 0); +MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA"); + #define MXS_I2C_CTRL0 (0x00) #define MXS_I2C_CTRL0_SET (0x04) @@ -146,6 +151,16 @@ struct mxs_i2c_dev { u32 cmd_err; struct i2c_adapter adapter; const struct mxs_i2c_speed_config *speed; + + /* DMA support components */ + bool dma_mode; + int dma_channel; + struct dma_chan *dmach; + struct mxs_dma_data dma_data; + uint32_t pio_data[2]; + uint32_t addr_data; + struct scatterlist sg_io[2]; + bool dma_read; }; static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) @@ -157,7 +172,11 @@ static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2); writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET); - writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, + if (i2c->dma_mode) + writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, + i2c->regs + MXS_I2C_QUEUECTRL_CLR); + else + writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, i2c->regs + MXS_I2C_QUEUECTRL_SET); } @@ -248,6 +267,150 @@ static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len) return 0; } +static void mxs_i2c_dma_finish(struct mxs_i2c_dev *i2c) +{ + if (i2c->dma_read) { + dma_unmap_sg(i2c->dev, &i2c->sg_io[0], 1, DMA_TO_DEVICE); + dma_unmap_sg(i2c->dev, &i2c->sg_io[1], 1, DMA_FROM_DEVICE); + } else { + dma_unmap_sg(i2c->dev, i2c->sg_io, 2, DMA_TO_DEVICE); + } +} + +static void mxs_i2c_dma_irq_callback(void *param) +{ + struct mxs_i2c_dev *i2c = param; + + complete(&i2c->cmd_complete); + mxs_i2c_dma_finish(i2c); +} + +static int mxs_i2c_dma_setup_xfer(struct i2c_adapter *adap, + struct i2c_msg *msg, uint32_t flags) +{ + struct dma_async_tx_descriptor *desc; + struct mxs_i2c_dev *i2c = i2c_get_adapdata(adap); + + if (msg->flags & I2C_M_RD) { + i2c->dma_read = 1; + i2c->addr_data = (msg->addr << 1) | I2C_SMBUS_READ; + + /* + * SELECT command. + */ + + /* Queue the PIO register write transfer. */ + i2c->pio_data[0] = MXS_CMD_I2C_SELECT; + desc = dmaengine_prep_slave_sg(i2c->dmach, + (struct scatterlist *)&i2c->pio_data[0], + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(i2c->dev, + "Failed to get PIO reg. write descriptor.\n"); + goto select_init_pio_fail; + } + + /* Queue the DMA data transfer. */ + sg_init_one(&i2c->sg_io[0], &i2c->addr_data, 1); + dma_map_sg(i2c->dev, &i2c->sg_io[0], 1, DMA_TO_DEVICE); + desc = dmaengine_prep_slave_sg(i2c->dmach, &i2c->sg_io[0], 1, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(i2c->dev, + "Failed to get DMA data write descriptor.\n"); + goto select_init_dma_fail; + } + + /* + * READ command. + */ + + /* Queue the PIO register write transfer. */ + i2c->pio_data[1] = flags | MXS_CMD_I2C_READ | + MXS_I2C_CTRL0_XFER_COUNT(msg->len); + desc = dmaengine_prep_slave_sg(i2c->dmach, + (struct scatterlist *)&i2c->pio_data[1], + 1, DMA_TRANS_NONE, DMA_PREP_INTERRUPT); + if (!desc) { + dev_err(i2c->dev, + "Failed to get PIO reg. write descriptor.\n"); + goto select_init_dma_fail; + } + + /* Queue the DMA data transfer. */ + sg_init_one(&i2c->sg_io[1], msg->buf, msg->len); + dma_map_sg(i2c->dev, &i2c->sg_io[1], 1, DMA_FROM_DEVICE); + desc = dmaengine_prep_slave_sg(i2c->dmach, &i2c->sg_io[1], 1, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(i2c->dev, + "Failed to get DMA data write descriptor.\n"); + goto read_init_dma_fail; + } + } else { + i2c->dma_read = 0; + i2c->addr_data = (msg->addr << 1) | I2C_SMBUS_WRITE; + + /* + * WRITE command. + */ + + /* Queue the PIO register write transfer. */ + i2c->pio_data[0] = flags | MXS_CMD_I2C_WRITE | + MXS_I2C_CTRL0_XFER_COUNT(msg->len + 1); + desc = dmaengine_prep_slave_sg(i2c->dmach, + (struct scatterlist *)&i2c->pio_data[0], + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(i2c->dev, + "Failed to get PIO reg. write descriptor.\n"); + goto write_init_pio_fail; + } + + /* Queue the DMA data transfer. */ + sg_init_table(i2c->sg_io, 2); + sg_set_buf(&i2c->sg_io[0], &i2c->addr_data, 1); + sg_set_buf(&i2c->sg_io[1], msg->buf, msg->len); + dma_map_sg(i2c->dev, i2c->sg_io, 2, DMA_TO_DEVICE); + desc = dmaengine_prep_slave_sg(i2c->dmach, i2c->sg_io, 2, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(i2c->dev, + "Failed to get DMA data write descriptor.\n"); + goto write_init_dma_fail; + } + } + + /* + * The last descriptor must have this callback, + * to finish the DMA transaction. + */ + desc->callback = mxs_i2c_dma_irq_callback; + desc->callback_param = i2c; + + /* Start the transfer. */ + dmaengine_submit(desc); + dma_async_issue_pending(i2c->dmach); + return 0; + +/* Read failpath. */ +read_init_dma_fail: + dma_unmap_sg(i2c->dev, &i2c->sg_io[1], 1, DMA_FROM_DEVICE); +select_init_dma_fail: + dma_unmap_sg(i2c->dev, &i2c->sg_io[0], 1, DMA_TO_DEVICE); +select_init_pio_fail: + return -EINVAL; + +/* Write failpath. */ +write_init_dma_fail: + dma_unmap_sg(i2c->dev, i2c->sg_io, 2, DMA_TO_DEVICE); +write_init_pio_fail: + return -EINVAL; +} + /* * Low level master read/write transaction. */ @@ -258,6 +421,8 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int ret; int flags; + flags = stop ? MXS_I2C_CTRL0_POST_SEND_STOP : 0; + dev_dbg(i2c->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", msg->addr, msg->len, msg->flags, stop); @@ -267,23 +432,29 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, init_completion(&i2c->cmd_complete); i2c->cmd_err = 0; - flags = stop ? MXS_I2C_CTRL0_POST_SEND_STOP : 0; - - if (msg->flags & I2C_M_RD) - mxs_i2c_pioq_setup_read(i2c, msg->addr, msg->len, flags); - else - mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf, msg->len, - flags); + if (i2c->dma_mode) { + ret = mxs_i2c_dma_setup_xfer(adap, msg, flags); + if (ret) + return ret; + } else { + if (msg->flags & I2C_M_RD) { + mxs_i2c_pioq_setup_read(i2c, msg->addr, + msg->len, flags); + } else { + mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf, + msg->len, flags); + } - writel(MXS_I2C_QUEUECTRL_QUEUE_RUN, + writel(MXS_I2C_QUEUECTRL_QUEUE_RUN, i2c->regs + MXS_I2C_QUEUECTRL_SET); + } ret = wait_for_completion_timeout(&i2c->cmd_complete, msecs_to_jiffies(1000)); if (ret == 0) goto timeout; - if ((!i2c->cmd_err) && (msg->flags & I2C_M_RD)) { + if (!i2c->dma_mode && !i2c->cmd_err && (msg->flags & I2C_M_RD)) { ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len); if (ret) goto timeout; @@ -301,6 +472,8 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, timeout: dev_dbg(i2c->dev, "Timeout!\n"); + if (i2c->dma_mode) + mxs_i2c_dma_finish(i2c); mxs_i2c_reset(i2c); return -ETIMEDOUT; } @@ -342,11 +515,13 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) /* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */ i2c->cmd_err = -EIO; - is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) & - MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0; + if (!i2c->dma_mode) { + is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) & + MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0; - if (is_last_cmd || i2c->cmd_err) - complete(&i2c->cmd_complete); + if (is_last_cmd || i2c->cmd_err) + complete(&i2c->cmd_complete); + } writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR); @@ -358,6 +533,21 @@ static const struct i2c_algorithm mxs_i2c_algo = { .functionality = mxs_i2c_func, }; +static bool mxs_i2c_dma_filter(struct dma_chan *chan, void *param) +{ + struct mxs_i2c_dev *i2c = param; + + if (!mxs_dma_is_apbx(chan)) + return false; + + if (chan->chan_id != i2c->dma_channel) + return false; + + chan->private = &i2c->dma_data; + + return true; +} + static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c) { uint32_t speed; @@ -365,6 +555,26 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c) struct device_node *node = dev->of_node; int ret; + /* + * The MXS I2C DMA mode is prefered and enabled by default. + * The PIO mode is still supported, but should be used only + * for debuging purposes etc. + */ + i2c->dma_mode = !use_pioqueue; + if (!i2c->dma_mode) + dev_info(dev, "Using PIOQUEUE mode for I2C transfers!\n"); + + /* + * TODO: This is a temporary solution and should be changed + * to use generic DMA binding later when the helpers get in. + */ + ret = of_property_read_u32(node, "fsl,i2c-dma-channel", + &i2c->dma_channel); + if (ret) { + dev_warn(dev, "Failed to get DMA channel, using PIOQUEUE!\n"); + i2c->dma_mode = 0; + } + ret = of_property_read_u32(node, "clock-frequency", &speed); if (ret) dev_warn(dev, "No I2C speed selected, using 100kHz\n"); @@ -384,7 +594,8 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) struct pinctrl *pinctrl; struct resource *res; resource_size_t res_size; - int err, irq; + int err, irq, dmairq; + dma_cap_mask_t mask; pinctrl = devm_pinctrl_get_select_default(dev); if (IS_ERR(pinctrl)) @@ -395,7 +606,10 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) + irq = platform_get_irq(pdev, 0); + dmairq = platform_get_irq(pdev, 1); + + if (!res || irq < 0 || dmairq < 0) return -ENOENT; res_size = resource_size(res); @@ -406,10 +620,6 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) if (!i2c->regs) return -EBUSY; - irq = platform_get_irq(pdev, 0); - if (irq < 0) - return irq; - err = devm_request_irq(dev, irq, mxs_i2c_isr, 0, dev_name(dev), i2c); if (err) return err; @@ -423,6 +633,18 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) return err; } + /* Setup the DMA */ + if (i2c->dma_mode) { + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + i2c->dma_data.chan_irq = dmairq; + i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c); + if (!i2c->dmach) { + dev_err(dev, "Failed to request dma\n"); + return -ENODEV; + } + } + platform_set_drvdata(pdev, i2c); /* Do reset to enforce correct startup after pinmuxing */ @@ -458,6 +680,9 @@ static int __devexit mxs_i2c_remove(struct platform_device *pdev) if (ret) return -EBUSY; + if (i2c->dmach) + dma_release_channel(i2c->dmach); + writel(MXS_I2C_CTRL0_SFTRST, i2c->regs + MXS_I2C_CTRL0_SET); platform_set_drvdata(pdev, NULL); -- cgit 1.4.1