From fc3756faa71e51664e3d43b401c273723047a049 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Thu, 6 Nov 2014 12:52:08 +0100 Subject: i2c: sh_mobile: Document SoC-specific bindings Explicitly list the various SoC-specific compatible properties. This allows checkpatch to validate DTSes. Signed-off-by: Geert Uytterhoeven Acked-by: Simon Horman Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt b/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt index d2153ce36fa8..c33e9a32d496 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt @@ -2,6 +2,15 @@ Device tree configuration for Renesas IIC (sh_mobile) driver Required properties: - compatible : "renesas,iic-". "renesas,rmobile-iic" as fallback + Examples with soctypes are: + - "renesas,iic-r8a73a4" (R-Mobile APE6) + - "renesas,iic-r8a7740" (R-Mobile A1) + - "renesas,iic-r8a7790" (R-Car H2) + - "renesas,iic-r8a7791" (R-Car M2-W) + - "renesas,iic-r8a7792" (R-Car V2H) + - "renesas,iic-r8a7793" (R-Car M2-N) + - "renesas,iic-r8a7794" (R-Car E2) + - "renesas,iic-sh73a0" (SH-Mobile AG5) - reg : address start and address range size of device - interrupts : interrupt of device - clocks : clock for device -- cgit v1.2.3 From 2d09581b4cc95c82b5fcc654e78b2d6de7350527 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Fri, 7 Nov 2014 11:11:41 +0100 Subject: i2c: sh_mobile: add DMA support Make it possible to transfer i2c message buffers via DMA. Start/Stop/Sending_Slave_Address is still handled using the old state machine, it is sending the actual data that is done via DMA. This is least intrusive and allows us to work with the message buffers directly instead of preparing a custom buffer which involves copying the data around. Signed-off-by: Wolfram Sang [wsa: fixed an uninitialized var problem] Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-sh_mobile.txt | 5 + drivers/i2c/busses/i2c-sh_mobile.c | 195 +++++++++++++++++++-- 2 files changed, 190 insertions(+), 10 deletions(-) (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt b/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt index c33e9a32d496..2bfc6e7ed094 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt @@ -19,6 +19,11 @@ Required properties: Optional properties: - clock-frequency : frequency of bus clock in Hz. Default 100kHz if unset. +- dmas : Must contain a list of two references to DMA + specifiers, one for transmission, and one for + reception. +- dma-names : Must contain a list of two DMA names, "tx" and "rx". + Pinctrl properties might be needed, too. See there. diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index de609be67793..d9a5622b89c8 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -1,6 +1,8 @@ /* * SuperH Mobile I2C Controller * + * Copyright (C) 2014 Wolfram Sang + * * Copyright (C) 2008 Magnus Damm * * Portions of the code based on out-of-tree driver i2c-sh7343.c @@ -18,6 +20,8 @@ #include #include +#include +#include #include #include #include @@ -110,6 +114,7 @@ enum sh_mobile_i2c_op { OP_TX_FIRST, OP_TX, OP_TX_STOP, + OP_TX_STOP_DATA, OP_TX_TO_RX, OP_RX, OP_RX_STOP, @@ -134,6 +139,11 @@ struct sh_mobile_i2c_data { int pos; int sr; bool send_stop; + + struct dma_chan *dma_tx; + struct dma_chan *dma_rx; + struct scatterlist sg; + enum dma_data_direction dma_direction; }; struct sh_mobile_dt_config { @@ -171,6 +181,8 @@ struct sh_mobile_dt_config { #define ICIC_ICCLB8 0x80 #define ICIC_ICCHB8 0x40 +#define ICIC_TDMAE 0x20 +#define ICIC_RDMAE 0x10 #define ICIC_ALE 0x08 #define ICIC_TACKE 0x04 #define ICIC_WAITE 0x02 @@ -332,8 +344,10 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, case OP_TX: /* write data */ iic_wr(pd, ICDR, data); break; - case OP_TX_STOP: /* write data and issue a stop afterwards */ + case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */ iic_wr(pd, ICDR, data); + /* fallthrough */ + case OP_TX_STOP: /* issue a stop */ iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS : ICCR_ICE | ICCR_TRS | ICCR_BBSY); break; @@ -389,13 +403,17 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd) { unsigned char data; - if (pd->pos == pd->msg->len) + if (pd->pos == pd->msg->len) { + /* Send stop if we haven't yet (DMA case) */ + if (pd->send_stop && (iic_rd(pd, ICCR) & ICCR_BBSY)) + i2c_op(pd, OP_TX_STOP, 0); return 1; + } sh_mobile_i2c_get_data(pd, &data); if (sh_mobile_i2c_is_last_byte(pd)) - i2c_op(pd, OP_TX_STOP, data); + i2c_op(pd, OP_TX_STOP_DATA, data); else if (sh_mobile_i2c_is_first_byte(pd)) i2c_op(pd, OP_TX_FIRST, data); else @@ -450,7 +468,7 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) struct platform_device *dev = dev_id; struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev); unsigned char sr; - int wakeup; + int wakeup = 0; sr = iic_rd(pd, ICSR); pd->sr |= sr; /* remember state */ @@ -459,15 +477,21 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) (pd->msg->flags & I2C_M_RD) ? "read" : "write", pd->pos, pd->msg->len); - if (sr & (ICSR_AL | ICSR_TACK)) { + /* Kick off TxDMA after preface was done */ + if (pd->dma_direction == DMA_TO_DEVICE && pd->pos == 0) + iic_set_clr(pd, ICIC, ICIC_TDMAE, 0); + else if (sr & (ICSR_AL | ICSR_TACK)) /* don't interrupt transaction - continue to issue stop */ iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK)); - wakeup = 0; - } else if (pd->msg->flags & I2C_M_RD) + else if (pd->msg->flags & I2C_M_RD) wakeup = sh_mobile_i2c_isr_rx(pd); else wakeup = sh_mobile_i2c_isr_tx(pd); + /* Kick off RxDMA after preface was done */ + if (pd->dma_direction == DMA_FROM_DEVICE && pd->pos == 1) + iic_set_clr(pd, ICIC, ICIC_RDMAE, 0); + if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */ iic_wr(pd, ICSR, sr & ~ICSR_WAIT); @@ -482,6 +506,79 @@ static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) return IRQ_HANDLED; } +static void sh_mobile_i2c_cleanup_dma(struct sh_mobile_i2c_data *pd) +{ + if (pd->dma_direction == DMA_NONE) + return; + else if (pd->dma_direction == DMA_FROM_DEVICE) + dmaengine_terminate_all(pd->dma_rx); + else if (pd->dma_direction == DMA_TO_DEVICE) + dmaengine_terminate_all(pd->dma_tx); + + dma_unmap_single(pd->dev, sg_dma_address(&pd->sg), + pd->msg->len, pd->dma_direction); + + pd->dma_direction = DMA_NONE; +} + +static void sh_mobile_i2c_dma_callback(void *data) +{ + struct sh_mobile_i2c_data *pd = data; + + dma_unmap_single(pd->dev, sg_dma_address(&pd->sg), + pd->msg->len, pd->dma_direction); + + pd->dma_direction = DMA_NONE; + pd->pos = pd->msg->len; + + iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE); +} + +static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd) +{ + bool read = pd->msg->flags & I2C_M_RD; + enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + struct dma_chan *chan = read ? pd->dma_rx : pd->dma_tx; + struct dma_async_tx_descriptor *txdesc; + dma_addr_t dma_addr; + dma_cookie_t cookie; + + if (!chan) + return; + + dma_addr = dma_map_single(pd->dev, pd->msg->buf, pd->msg->len, dir); + if (dma_mapping_error(pd->dev, dma_addr)) { + dev_dbg(pd->dev, "dma map failed, using PIO\n"); + return; + } + + sg_dma_len(&pd->sg) = pd->msg->len; + sg_dma_address(&pd->sg) = dma_addr; + + pd->dma_direction = dir; + + txdesc = dmaengine_prep_slave_sg(chan, &pd->sg, 1, + read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!txdesc) { + dev_dbg(pd->dev, "dma prep slave sg failed, using PIO\n"); + sh_mobile_i2c_cleanup_dma(pd); + return; + } + + txdesc->callback = sh_mobile_i2c_dma_callback; + txdesc->callback_param = pd; + + cookie = dmaengine_submit(txdesc); + if (dma_submit_error(cookie)) { + dev_dbg(pd->dev, "submitting dma failed, using PIO\n"); + sh_mobile_i2c_cleanup_dma(pd); + return; + } + + dma_async_issue_pending(chan); +} + static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg, bool do_init) { @@ -506,6 +603,9 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg, pd->pos = -1; pd->sr = 0; + if (pd->msg->len > 8) + sh_mobile_i2c_xfer_dma(pd); + /* Enable all interrupts to begin with */ iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); return 0; @@ -589,6 +689,9 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, 5 * HZ); if (!k) { dev_err(pd->dev, "Transfer request timed out\n"); + if (pd->dma_direction != DMA_NONE) + sh_mobile_i2c_cleanup_dma(pd); + err = -ETIMEDOUT; break; } @@ -639,6 +742,62 @@ static const struct of_device_id sh_mobile_i2c_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids); +static int sh_mobile_i2c_request_dma_chan(struct device *dev, enum dma_transfer_direction dir, + dma_addr_t port_addr, struct dma_chan **chan_ptr) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + struct dma_slave_config cfg; + char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx"; + int ret; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + *chan_ptr = NULL; + + chan = dma_request_slave_channel_reason(dev, chan_name); + if (IS_ERR(chan)) { + ret = PTR_ERR(chan); + dev_dbg(dev, "request_channel failed for %s (%d)\n", chan_name, ret); + return ret; + } + + memset(&cfg, 0, sizeof(cfg)); + cfg.direction = dir; + if (dir == DMA_MEM_TO_DEV) { + cfg.dst_addr = port_addr; + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } else { + cfg.src_addr = port_addr; + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } + + ret = dmaengine_slave_config(chan, &cfg); + if (ret) { + dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret); + dma_release_channel(chan); + return ret; + } + + *chan_ptr = chan; + + dev_dbg(dev, "got DMA channel for %s\n", chan_name); + return 0; +} + +static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd) +{ + if (pd->dma_tx) { + dma_release_channel(pd->dma_tx); + pd->dma_tx = NULL; + } + + if (pd->dma_rx) { + dma_release_channel(pd->dma_rx); + pd->dma_rx = NULL; + } +} + static int sh_mobile_i2c_hook_irqs(struct platform_device *dev) { struct resource *res; @@ -725,6 +884,21 @@ static int sh_mobile_i2c_probe(struct platform_device *dev) if (ret) return ret; + /* Init DMA */ + sg_init_table(&pd->sg, 1); + pd->dma_direction = DMA_NONE; + ret = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM, + res->start + ICDR, &pd->dma_rx); + if (ret == -EPROBE_DEFER) + return ret; + + ret = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV, + res->start + ICDR, &pd->dma_tx); + if (ret == -EPROBE_DEFER) { + sh_mobile_i2c_release_dma(pd); + return ret; + } + /* Enable Runtime PM for this device. * * Also tell the Runtime PM core to ignore children @@ -756,6 +930,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev) ret = i2c_add_numbered_adapter(adap); if (ret < 0) { + sh_mobile_i2c_release_dma(pd); dev_err(&dev->dev, "cannot add numbered adapter\n"); return ret; } @@ -772,6 +947,7 @@ static int sh_mobile_i2c_remove(struct platform_device *dev) struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev); i2c_del_adapter(&pd->adap); + sh_mobile_i2c_release_dma(pd); pm_runtime_disable(&dev->dev); return 0; } @@ -808,16 +984,15 @@ static int __init sh_mobile_i2c_adap_init(void) { return platform_driver_register(&sh_mobile_i2c_driver); } +subsys_initcall(sh_mobile_i2c_adap_init); static void __exit sh_mobile_i2c_adap_exit(void) { platform_driver_unregister(&sh_mobile_i2c_driver); } - -subsys_initcall(sh_mobile_i2c_adap_init); module_exit(sh_mobile_i2c_adap_exit); MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver"); -MODULE_AUTHOR("Magnus Damm"); +MODULE_AUTHOR("Magnus Damm and Wolfram Sang"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:i2c-sh_mobile"); -- cgit v1.2.3 From 039e60ed6cb6715d168943de99a4aececcb65e15 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Thu, 13 Nov 2014 10:25:11 -0300 Subject: DT: i2c: Add binding document for IMG I2C SCB Introduce a devicetree binding for Imagination Technologies I2C SCB controller. Reviewed-by: Andrew Bresticker Signed-off-by: James Hogan Signed-off-by: Ezequiel Garcia Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-img-scb.txt | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-img-scb.txt (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/i2c-img-scb.txt b/Documentation/devicetree/bindings/i2c/i2c-img-scb.txt new file mode 100644 index 000000000000..b6461602dca5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-img-scb.txt @@ -0,0 +1,26 @@ +IMG Serial Control Bus (SCB) I2C Controller + +Required Properties: +- compatible: "img,scb-i2c" +- reg: Physical base address and length of controller registers +- interrupts: Interrupt number used by the controller +- clocks : Should contain a clock specifier for each entry in clock-names +- clock-names : Should contain the following entries: + "scb", for the SCB core clock. + "sys", for the system clock. +- clock-frequency: The I2C bus frequency in Hz +- #address-cells: Should be <1> +- #size-cells: Should be <0> + +Example: + +i2c@18100000 { + compatible = "img,scb-i2c"; + reg = <0x18100000 0x200>; + interrupts = ; + clocks = <&i2c0_clk>, <&system_clk>; + clock-names = "scb", "sys"; + clock-frequency = <400000>; + #address-cells = <1>; + #size-cells = <0>; +}; -- cgit v1.2.3 From ce1a78840ff7ab846065d5b65eaac959bafe1949 Mon Sep 17 00:00:00 2001 From: Yao Yuan Date: Tue, 18 Nov 2014 18:31:06 +0800 Subject: i2c: imx: add DMA support for freescale i2c driver 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. DMA is optional, even DMA request unsuccessfully, i2c can also work well. Signed-off-by: Yuan Yao Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-imx.txt | 11 + drivers/i2c/busses/i2c-imx.c | 335 +++++++++++++++++++++- 2 files changed, 344 insertions(+), 2 deletions(-) (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt index 4a8513e44740..52d37fd8d3e5 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt @@ -11,6 +11,8 @@ Required properties: Optional properties: - clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz. The absence of the propoerty indicates the default frequency 100 kHz. +- dmas: A list of two dma specifiers, one for each entry in dma-names. +- dma-names: should contain "tx" and "rx". Examples: @@ -26,3 +28,12 @@ i2c@70038000 { /* HS-I2C on i.MX51 */ interrupts = <64>; clock-frequency = <400000>; }; + +i2c0: i2c@40066000 { /* i2c0 on vf610 */ + compatible = "fsl,vf610-i2c"; + reg = <0x40066000 0x1000>; + interrupts =<0 71 0x04>; + dmas = <&edma0 0 50>, + <&edma0 0 51>; + dma-names = "rx","tx"; +}; diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d137289edfca..d0668d0d626d 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -33,7 +33,11 @@ *******************************************************************************/ #include +#include #include +#include +#include +#include #include #include #include @@ -44,6 +48,7 @@ #include #include #include +#include #include #include #include @@ -58,6 +63,15 @@ /* Default value */ #define IMX_I2C_BIT_RATE 100000 /* 100kHz */ +/* + * Enable DMA if transfer byte size is bigger than this threshold. + * As the hardware request, it must bigger than 4 bytes.\ + * I have set '16' here, maybe it's not the best but I think it's + * the appropriate. + */ +#define DMA_THRESHOLD 16 +#define DMA_TIMEOUT 1000 + /* IMX I2C registers: * the I2C register offset is different between SoCs, * to provid support for all these chips, split the @@ -83,6 +97,7 @@ #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 @@ -169,6 +184,17 @@ struct imx_i2c_hwdata { unsigned i2cr_ien_opcode; }; +struct imx_i2c_dma { + struct dma_chan *chan_tx; + struct dma_chan *chan_rx; + struct dma_chan *chan_using; + struct completion cmd_complete; + dma_addr_t dma_buf; + unsigned int dma_len; + enum dma_transfer_direction dma_transfer_dir; + enum dma_data_direction dma_data_dir; +}; + struct imx_i2c_struct { struct i2c_adapter adapter; struct clk *clk; @@ -181,6 +207,8 @@ struct imx_i2c_struct { unsigned int cur_clk; unsigned int bitrate; const struct imx_i2c_hwdata *hwdata; + + struct imx_i2c_dma *dma; }; static const struct imx_i2c_hwdata imx1_i2c_hwdata = { @@ -251,6 +279,138 @@ 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 void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, + dma_addr_t phy_addr) +{ + 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; + + dma->chan_tx = dma_request_slave_channel(dev, "tx"); + if (!dma->chan_tx) { + dev_dbg(dev, "can't request DMA tx channel\n"); + ret = -ENODEV; + goto fail_al; + } + + dma_sconfig.dst_addr = 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_dbg(dev, "can't configure tx channel\n"); + goto fail_tx; + } + + dma->chan_rx = dma_request_slave_channel(dev, "rx"); + if (!dma->chan_rx) { + dev_dbg(dev, "can't request DMA rx channel\n"); + ret = -ENODEV; + goto fail_tx; + } + + dma_sconfig.src_addr = 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_dbg(dev, "can't configure rx channel\n"); + goto fail_rx; + } + + i2c_imx->dma = dma; + init_completion(&dma->cmd_complete); + 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; + +fail_rx: + dma_release_channel(dma->chan_rx); +fail_tx: + dma_release_channel(dma->chan_tx); +fail_al: + devm_kfree(dev, dma); + dev_info(dev, "can't use DMA\n"); +} + +static void i2c_imx_dma_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_using->device->dev, dma->dma_buf, + dma->dma_len, dma->dma_data_dir); + complete(&dma->cmd_complete); +} + +static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs) +{ + struct imx_i2c_dma *dma = i2c_imx->dma; + struct dma_async_tx_descriptor *txdesc; + struct device *dev = &i2c_imx->adapter.dev; + struct device *chan_dev = dma->chan_using->device->dev; + + dma->dma_buf = dma_map_single(chan_dev, msgs->buf, + dma->dma_len, dma->dma_data_dir); + if (dma_mapping_error(chan_dev, dma->dma_buf)) { + dev_err(dev, "DMA mapping failed\n"); + goto err_map; + } + + txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf, + dma->dma_len, dma->dma_transfer_dir, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!txdesc) { + dev_err(dev, "Not able to get desc for DMA xfer\n"); + goto err_desc; + } + + txdesc->callback = i2c_imx_dma_callback; + txdesc->callback_param = i2c_imx; + if (dma_submit_error(dmaengine_submit(txdesc))) { + dev_err(dev, "DMA submit failed\n"); + goto err_submit; + } + + dma_async_issue_pending(dma->chan_using); + return 0; + +err_submit: +err_desc: + dma_unmap_single(chan_dev, dma->dma_buf, + dma->dma_len, dma->dma_data_dir); +err_map: + return -EINVAL; +} + +static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx) +{ + struct imx_i2c_dma *dma = i2c_imx->dma; + + dma->dma_buf = 0; + dma->dma_len = 0; + + dma_release_channel(dma->chan_tx); + dma->chan_tx = NULL; + + dma_release_channel(dma->chan_rx); + dma->chan_rx = NULL; + + dma->chan_using = NULL; +} + /** Functions for IMX I2C adapter driver *************************************** *******************************************************************************/ @@ -382,6 +542,7 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) i2c_imx->stopped = 0; temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK; + temp &= ~I2CR_DMAEN; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); return result; } @@ -395,6 +556,8 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx) dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); temp &= ~(I2CR_MSTA | I2CR_MTX); + if (i2c_imx->dma) + temp &= ~I2CR_DMAEN; imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); } if (is_imx1_i2c(i2c_imx)) { @@ -435,6 +598,159 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) return IRQ_NONE; } +static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs) +{ + int result; + unsigned int temp = 0; + unsigned long orig_jiffies = jiffies; + struct imx_i2c_dma *dma = i2c_imx->dma; + struct device *dev = &i2c_imx->adapter.dev; + + dma->chan_using = dma->chan_tx; + dma->dma_transfer_dir = DMA_MEM_TO_DEV; + dma->dma_data_dir = DMA_TO_DEVICE; + dma->dma_len = msgs->len - 1; + result = i2c_imx_dma_xfer(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. + * The first byte must be transmitted by the CPU. + */ + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR); + reinit_completion(&i2c_imx->dma->cmd_complete); + result = wait_for_completion_timeout( + &i2c_imx->dma->cmd_complete, + msecs_to_jiffies(DMA_TIMEOUT)); + if (result <= 0) { + dmaengine_terminate_all(dma->chan_using); + return result ?: -ETIMEDOUT; + } + + /* Waiting for transfer complete. */ + while (1) { + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + if (temp & I2SR_ICF) + break; + if (time_after(jiffies, orig_jiffies + + msecs_to_jiffies(DMA_TIMEOUT))) { + dev_dbg(dev, "<%s> Timeout\n", __func__); + return -ETIMEDOUT; + } + schedule(); + } + + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp &= ~I2CR_DMAEN; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + + /* The last data byte must be transferred by the CPU. */ + 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_dma_read(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs, bool is_lastmsg) +{ + int result; + unsigned int temp; + unsigned long orig_jiffies = jiffies; + struct imx_i2c_dma *dma = i2c_imx->dma; + struct device *dev = &i2c_imx->adapter.dev; + + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp |= I2CR_DMAEN; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + + dma->chan_using = dma->chan_rx; + dma->dma_transfer_dir = DMA_DEV_TO_MEM; + dma->dma_data_dir = DMA_FROM_DEVICE; + /* The last two data bytes must be transferred by the CPU. */ + dma->dma_len = msgs->len - 2; + result = i2c_imx_dma_xfer(i2c_imx, msgs); + if (result) + return result; + + reinit_completion(&i2c_imx->dma->cmd_complete); + result = wait_for_completion_timeout( + &i2c_imx->dma->cmd_complete, + msecs_to_jiffies(DMA_TIMEOUT)); + if (result <= 0) { + dmaengine_terminate_all(dma->chan_using); + return result ?: -ETIMEDOUT; + } + + /* waiting for transfer complete. */ + while (1) { + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + if (temp & I2SR_ICF) + break; + if (time_after(jiffies, orig_jiffies + + msecs_to_jiffies(DMA_TIMEOUT))) { + dev_dbg(dev, "<%s> Timeout\n", __func__); + return -ETIMEDOUT; + } + schedule(); + } + + 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; + + if (is_lastmsg) { + /* + * It must generate STOP before read I2DR to prevent + * controller from generating another clock cycle + */ + dev_dbg(dev, "<%s> clear MSTA\n", __func__); + 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; + } else { + /* + * For i2c master receiver repeat restart operation like: + * read -> repeat MSTA -> read/write + * The controller must set MTX before read the last byte in + * the first read operation, otherwise the first read cost + * one extra clock cycle. + */ + temp = readb(i2c_imx->base + IMX_I2C_I2CR); + temp |= I2CR_MTX; + writeb(temp, i2c_imx->base + IMX_I2C_I2CR); + } + msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + + return 0; +} + static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) { int i, result; @@ -504,6 +820,9 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); + if (i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data) + return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg); + /* read data */ for (i = 0; i < msgs->len; i++) { u8 len = 0; @@ -618,8 +937,12 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, #endif if (msgs[i].flags & I2C_M_RD) result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg); - else - result = i2c_imx_write(i2c_imx, &msgs[i]); + else { + if (i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD) + result = i2c_imx_dma_write(i2c_imx, &msgs[i]); + else + result = i2c_imx_write(i2c_imx, &msgs[i]); + } if (result) goto fail0; } @@ -654,6 +977,7 @@ static int i2c_imx_probe(struct platform_device *pdev) struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev); void __iomem *base; int irq, ret; + dma_addr_t phy_addr; dev_dbg(&pdev->dev, "<%s>\n", __func__); @@ -668,6 +992,7 @@ static int i2c_imx_probe(struct platform_device *pdev) if (IS_ERR(base)) return PTR_ERR(base); + phy_addr = (dma_addr_t)res->start; i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL); if (!i2c_imx) return -ENOMEM; @@ -742,6 +1067,9 @@ 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*/ + i2c_imx_dma_request(i2c_imx, phy_addr); + return 0; /* Return OK */ clk_disable: @@ -757,6 +1085,9 @@ 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->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); -- cgit v1.2.3 From 30021e3707a75cc29dc1252c062d374151c5985f Mon Sep 17 00:00:00 2001 From: Beniamino Galvani Date: Thu, 13 Nov 2014 20:32:01 +0100 Subject: i2c: add support for Amlogic Meson I2C controller This is a driver for the I2C controller found in Amlogic Meson SoCs. Signed-off-by: Beniamino Galvani Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-meson.txt | 24 + drivers/i2c/busses/Kconfig | 7 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-meson.c | 492 +++++++++++++++++++++ 4 files changed, 524 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-meson.txt create mode 100644 drivers/i2c/busses/i2c-meson.c (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/i2c-meson.txt b/Documentation/devicetree/bindings/i2c/i2c-meson.txt new file mode 100644 index 000000000000..682f9a6f766e --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-meson.txt @@ -0,0 +1,24 @@ +Amlogic Meson I2C controller + +Required properties: + - compatible: must be "amlogic,meson6-i2c" + - reg: physical address and length of the device registers + - interrupts: a single interrupt specifier + - clocks: clock for the device + - #address-cells: should be <1> + - #size-cells: should be <0> + +Optional properties: +- clock-frequency: the desired I2C bus clock frequency in Hz; in + absence of this property the default value is used (100 kHz). + +Examples: + + i2c@c8100500 { + compatible = "amlogic,meson6-i2c"; + reg = <0xc8100500 0x20>; + interrupts = <0 92 1>; + clocks = <&clk81>; + #address-cells = <1>; + #size-cells = <0>; + }; diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 03c6119325ef..a940e336351d 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -564,6 +564,13 @@ config I2C_KEMPLD This driver can also be built as a module. If so, the module will be called i2c-kempld. +config I2C_MESON + tristate "Amlogic Meson I2C controller" + depends on ARCH_MESON + help + If you say yes to this option, support will be included for the + I2C interface on the Amlogic Meson family of SoCs. + config I2C_MPC tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx" depends on PPC diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 84861ead6be9..e9b4a1f8431f 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_I2C_IMG) += i2c-img-scb.o obj-$(CONFIG_I2C_IMX) += i2c-imx.o obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o +obj-$(CONFIG_I2C_MESON) += i2c-meson.o obj-$(CONFIG_I2C_MPC) += i2c-mpc.o obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_MXS) += i2c-mxs.o diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c new file mode 100644 index 000000000000..5e176adca8e8 --- /dev/null +++ b/drivers/i2c/busses/i2c-meson.c @@ -0,0 +1,492 @@ +/* + * I2C bus driver for Amlogic Meson SoCs + * + * Copyright (C) 2014 Beniamino Galvani + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Meson I2C register map */ +#define REG_CTRL 0x00 +#define REG_SLAVE_ADDR 0x04 +#define REG_TOK_LIST0 0x08 +#define REG_TOK_LIST1 0x0c +#define REG_TOK_WDATA0 0x10 +#define REG_TOK_WDATA1 0x14 +#define REG_TOK_RDATA0 0x18 +#define REG_TOK_RDATA1 0x1c + +/* Control register fields */ +#define REG_CTRL_START BIT(0) +#define REG_CTRL_ACK_IGNORE BIT(1) +#define REG_CTRL_STATUS BIT(2) +#define REG_CTRL_ERROR BIT(3) +#define REG_CTRL_CLKDIV_SHIFT 12 +#define REG_CTRL_CLKDIV_MASK ((BIT(10) - 1) << REG_CTRL_CLKDIV_SHIFT) + +#define I2C_TIMEOUT_MS 500 +#define DEFAULT_FREQ 100000 + +enum { + TOKEN_END = 0, + TOKEN_START, + TOKEN_SLAVE_ADDR_WRITE, + TOKEN_SLAVE_ADDR_READ, + TOKEN_DATA, + TOKEN_DATA_LAST, + TOKEN_STOP, +}; + +enum { + STATE_IDLE, + STATE_READ, + STATE_WRITE, + STATE_STOP, +}; + +/** + * struct meson_i2c - Meson I2C device private data + * + * @adap: I2C adapter instance + * @dev: Pointer to device structure + * @regs: Base address of the device memory mapped registers + * @clk: Pointer to clock structure + * @irq: IRQ number + * @msg: Pointer to the current I2C message + * @state: Current state in the driver state machine + * @last: Flag set for the last message in the transfer + * @count: Number of bytes to be sent/received in current transfer + * @pos: Current position in the send/receive buffer + * @error: Flag set when an error is received + * @lock: To avoid race conditions between irq handler and xfer code + * @done: Completion used to wait for transfer termination + * @frequency: Operating frequency of I2C bus clock + * @tokens: Sequence of tokens to be written to the device + * @num_tokens: Number of tokens + */ +struct meson_i2c { + struct i2c_adapter adap; + struct device *dev; + void __iomem *regs; + struct clk *clk; + int irq; + + struct i2c_msg *msg; + int state; + bool last; + int count; + int pos; + int error; + + spinlock_t lock; + struct completion done; + unsigned int frequency; + u32 tokens[2]; + int num_tokens; +}; + +static void meson_i2c_set_mask(struct meson_i2c *i2c, int reg, u32 mask, + u32 val) +{ + u32 data; + + data = readl(i2c->regs + reg); + data &= ~mask; + data |= val & mask; + writel(data, i2c->regs + reg); +} + +static void meson_i2c_reset_tokens(struct meson_i2c *i2c) +{ + i2c->tokens[0] = 0; + i2c->tokens[1] = 0; + i2c->num_tokens = 0; +} + +static void meson_i2c_add_token(struct meson_i2c *i2c, int token) +{ + if (i2c->num_tokens < 8) + i2c->tokens[0] |= (token & 0xf) << (i2c->num_tokens * 4); + else + i2c->tokens[1] |= (token & 0xf) << ((i2c->num_tokens % 8) * 4); + + i2c->num_tokens++; +} + +static void meson_i2c_write_tokens(struct meson_i2c *i2c) +{ + writel(i2c->tokens[0], i2c->regs + REG_TOK_LIST0); + writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1); +} + +static void meson_i2c_set_clk_div(struct meson_i2c *i2c) +{ + unsigned long clk_rate = clk_get_rate(i2c->clk); + unsigned int div; + + div = DIV_ROUND_UP(clk_rate, i2c->frequency * 4); + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV_MASK, + div << REG_CTRL_CLKDIV_SHIFT); + + dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__, + clk_rate, i2c->frequency, div); +} + +static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len) +{ + u32 rdata0, rdata1; + int i; + + rdata0 = readl(i2c->regs + REG_TOK_RDATA0); + rdata1 = readl(i2c->regs + REG_TOK_RDATA1); + + dev_dbg(i2c->dev, "%s: data %08x %08x len %d\n", __func__, + rdata0, rdata1, len); + + for (i = 0; i < min_t(int, 4, len); i++) + *buf++ = (rdata0 >> i * 8) & 0xff; + + for (i = 4; i < min_t(int, 8, len); i++) + *buf++ = (rdata1 >> (i - 4) * 8) & 0xff; +} + +static void meson_i2c_put_data(struct meson_i2c *i2c, char *buf, int len) +{ + u32 wdata0 = 0, wdata1 = 0; + int i; + + for (i = 0; i < min_t(int, 4, len); i++) + wdata0 |= *buf++ << (i * 8); + + for (i = 4; i < min_t(int, 8, len); i++) + wdata1 |= *buf++ << ((i - 4) * 8); + + writel(wdata0, i2c->regs + REG_TOK_WDATA0); + writel(wdata0, i2c->regs + REG_TOK_WDATA1); + + dev_dbg(i2c->dev, "%s: data %08x %08x len %d\n", __func__, + wdata0, wdata1, len); +} + +static void meson_i2c_prepare_xfer(struct meson_i2c *i2c) +{ + bool write = !(i2c->msg->flags & I2C_M_RD); + int i; + + i2c->count = min_t(int, i2c->msg->len - i2c->pos, 8); + + for (i = 0; i < i2c->count - 1; i++) + meson_i2c_add_token(i2c, TOKEN_DATA); + + if (i2c->count) { + if (write || i2c->pos + i2c->count < i2c->msg->len) + meson_i2c_add_token(i2c, TOKEN_DATA); + else + meson_i2c_add_token(i2c, TOKEN_DATA_LAST); + } + + if (write) + meson_i2c_put_data(i2c, i2c->msg->buf + i2c->pos, i2c->count); +} + +static void meson_i2c_stop(struct meson_i2c *i2c) +{ + dev_dbg(i2c->dev, "%s: last %d\n", __func__, i2c->last); + + if (i2c->last) { + i2c->state = STATE_STOP; + meson_i2c_add_token(i2c, TOKEN_STOP); + } else { + i2c->state = STATE_IDLE; + complete_all(&i2c->done); + } +} + +static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) +{ + struct meson_i2c *i2c = dev_id; + unsigned int ctrl; + + spin_lock(&i2c->lock); + + meson_i2c_reset_tokens(i2c); + ctrl = readl(i2c->regs + REG_CTRL); + + dev_dbg(i2c->dev, "irq: state %d, pos %d, count %d, ctrl %08x\n", + i2c->state, i2c->pos, i2c->count, ctrl); + + if (ctrl & REG_CTRL_ERROR && i2c->state != STATE_IDLE) { + /* + * The bit is set when the IGNORE_NAK bit is cleared + * and the device didn't respond. In this case, the + * I2C controller automatically generates a STOP + * condition. + */ + dev_dbg(i2c->dev, "error bit set\n"); + i2c->error = -ENXIO; + i2c->state = STATE_IDLE; + complete_all(&i2c->done); + goto out; + } + + switch (i2c->state) { + case STATE_READ: + if (i2c->count > 0) { + meson_i2c_get_data(i2c, i2c->msg->buf + i2c->pos, + i2c->count); + i2c->pos += i2c->count; + } + + if (i2c->pos >= i2c->msg->len) { + meson_i2c_stop(i2c); + break; + } + + meson_i2c_prepare_xfer(i2c); + break; + case STATE_WRITE: + i2c->pos += i2c->count; + + if (i2c->pos >= i2c->msg->len) { + meson_i2c_stop(i2c); + break; + } + + meson_i2c_prepare_xfer(i2c); + break; + case STATE_STOP: + i2c->state = STATE_IDLE; + complete_all(&i2c->done); + break; + case STATE_IDLE: + break; + } + +out: + if (i2c->state != STATE_IDLE) { + /* Restart the processing */ + meson_i2c_write_tokens(i2c); + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0); + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, + REG_CTRL_START); + } + + spin_unlock(&i2c->lock); + + return IRQ_HANDLED; +} + +static void meson_i2c_do_start(struct meson_i2c *i2c, struct i2c_msg *msg) +{ + int token; + + token = (msg->flags & I2C_M_RD) ? TOKEN_SLAVE_ADDR_READ : + TOKEN_SLAVE_ADDR_WRITE; + + writel(msg->addr << 1, i2c->regs + REG_SLAVE_ADDR); + meson_i2c_add_token(i2c, TOKEN_START); + meson_i2c_add_token(i2c, token); +} + +static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg, + int last) +{ + unsigned long time_left, flags; + int ret = 0; + + i2c->msg = msg; + i2c->last = last; + i2c->pos = 0; + i2c->count = 0; + i2c->error = 0; + + meson_i2c_reset_tokens(i2c); + + flags = (msg->flags & I2C_M_IGNORE_NAK) ? REG_CTRL_ACK_IGNORE : 0; + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_ACK_IGNORE, flags); + + if (!(msg->flags & I2C_M_NOSTART)) + meson_i2c_do_start(i2c, msg); + + i2c->state = (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE; + meson_i2c_prepare_xfer(i2c); + meson_i2c_write_tokens(i2c); + reinit_completion(&i2c->done); + + /* Start the transfer */ + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, REG_CTRL_START); + + time_left = msecs_to_jiffies(I2C_TIMEOUT_MS); + time_left = wait_for_completion_timeout(&i2c->done, time_left); + + /* + * Protect access to i2c struct and registers from interrupt + * handlers triggered by a transfer terminated after the + * timeout period + */ + spin_lock_irqsave(&i2c->lock, flags); + + /* Abort any active operation */ + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0); + + if (!time_left) { + i2c->state = STATE_IDLE; + ret = -ETIMEDOUT; + } + + if (i2c->error) + ret = i2c->error; + + spin_unlock_irqrestore(&i2c->lock, flags); + + return ret; +} + +static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct meson_i2c *i2c = adap->algo_data; + int i, ret = 0, count = 0; + + clk_enable(i2c->clk); + meson_i2c_set_clk_div(i2c); + + for (i = 0; i < num; i++) { + ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1); + if (ret) + break; + count++; + } + + clk_disable(i2c->clk); + + return ret ? ret : count; +} + +static u32 meson_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm meson_i2c_algorithm = { + .master_xfer = meson_i2c_xfer, + .functionality = meson_i2c_func, +}; + +static int meson_i2c_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct meson_i2c *i2c; + struct resource *mem; + int ret = 0; + + i2c = devm_kzalloc(&pdev->dev, sizeof(struct meson_i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &i2c->frequency)) + i2c->frequency = DEFAULT_FREQ; + + i2c->dev = &pdev->dev; + platform_set_drvdata(pdev, i2c); + + spin_lock_init(&i2c->lock); + init_completion(&i2c->done); + + i2c->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "can't get device clock\n"); + return PTR_ERR(i2c->clk); + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + i2c->regs = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(i2c->regs)) + return PTR_ERR(i2c->regs); + + i2c->irq = platform_get_irq(pdev, 0); + if (i2c->irq < 0) { + dev_err(&pdev->dev, "can't find IRQ\n"); + return i2c->irq; + } + + ret = devm_request_irq(&pdev->dev, i2c->irq, meson_i2c_irq, + 0, dev_name(&pdev->dev), i2c); + if (ret < 0) { + dev_err(&pdev->dev, "can't request IRQ\n"); + return ret; + } + + ret = clk_prepare(i2c->clk); + if (ret < 0) { + dev_err(&pdev->dev, "can't prepare clock\n"); + return ret; + } + + strlcpy(i2c->adap.name, "Meson I2C adapter", + sizeof(i2c->adap.name)); + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &meson_i2c_algorithm; + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.dev.of_node = np; + i2c->adap.algo_data = i2c; + + /* + * A transfer is triggered when START bit changes from 0 to 1. + * Ensure that the bit is set to 0 after probe + */ + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0); + + ret = i2c_add_adapter(&i2c->adap); + if (ret < 0) { + dev_err(&pdev->dev, "can't register adapter\n"); + clk_unprepare(i2c->clk); + return ret; + } + + return 0; +} + +static int meson_i2c_remove(struct platform_device *pdev) +{ + struct meson_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + clk_unprepare(i2c->clk); + + return 0; +} + +static const struct of_device_id meson_i2c_match[] = { + { .compatible = "amlogic,meson6-i2c" }, + { }, +}; + +static struct platform_driver meson_i2c_driver = { + .probe = meson_i2c_probe, + .remove = meson_i2c_remove, + .driver = { + .name = "meson-i2c", + .of_match_table = meson_i2c_match, + }, +}; + +module_platform_driver(meson_i2c_driver); + +MODULE_DESCRIPTION("Amlogic Meson I2C Bus driver"); +MODULE_AUTHOR("Beniamino Galvani "); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3 From fa040c24b19d8067c57fa488660361b122d2138e Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 14 Nov 2014 17:03:30 +0100 Subject: DT: i2c: Add more devices handled by the rtc-rs5c372 driver This allows checkpatch to validate more DTSes. Signed-off-by: Geert Uytterhoeven Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/trivial-devices.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt index fbde415078e6..7a2bbea61b70 100644 --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt @@ -74,7 +74,12 @@ ovti,ov5642 OV5642: Color CMOS QSXGA (5-megapixel) Image Sensor with OmniBSI an pericom,pt7c4338 Real-time Clock Module plx,pex8648 48-Lane, 12-Port PCI Express Gen 2 (5.0 GT/s) Switch ramtron,24c64 i2c serial eeprom (24cxx) +ricoh,r2025sd I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC +ricoh,r2221tl I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC ricoh,rs5c372a I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC +ricoh,rs5c372b I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC +ricoh,rv5c386 I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC +ricoh,rv5c387a I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC samsung,24ad0xd1 S524AD0XF1 (128K/256K-bit Serial EEPROM for Low Power) sii,s35390a 2-wire CMOS real-time clock st-micro,24c256 i2c serial eeprom (24cxx) -- cgit v1.2.3 From 11321585f91bcb6de64376c3d767fb3200e20b53 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 14 Nov 2014 17:03:31 +0100 Subject: DT: i2c: Add more devices handled by the adxl34x-i2c driver This allows checkpatch to validate more DTSes. Signed-off-by: Geert Uytterhoeven Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/trivial-devices.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt index 7a2bbea61b70..e0beef4f8cff 100644 --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt @@ -17,6 +17,9 @@ adi,adt7473 +/-1C TDM Extended Temp Range I.C adi,adt7475 +/-1C TDM Extended Temp Range I.C adi,adt7476 +/-1C TDM Extended Temp Range I.C adi,adt7490 +/-1C TDM Extended Temp Range I.C +adi,adxl345 Three-Axis Digital Accelerometer +adi,adxl346 Three-Axis Digital Accelerometer +adi,adxl34x Three-Axis Digital Accelerometer at,24c08 i2c serial eeprom (24cxx) atmel,24c00 i2c serial eeprom (24cxx) atmel,24c01 i2c serial eeprom (24cxx) -- cgit v1.2.3 From 8e2596e81a9dd8f9efcf78476f3990f211e25edb Mon Sep 17 00:00:00 2001 From: Doug Anderson Date: Fri, 5 Dec 2014 10:49:39 -0800 Subject: i2c: designware: Fix falling time bindings doc In (6468276 i2c: designware: make SCL and SDA falling time configurable) new device tree properties were added for setting the falling time of SDA and SCL. The device tree bindings doc had a typo in it: it forgot the "-ns" suffix for both properies in the prose of the bindings. I assume this is a typo because: * The source code includes the "-ns" * The example in the bindings includes the "-ns". Fix the typo. Signed-off-by: Doug Anderson Fixes: 6468276b2206 ("i2c: designware: make SCL and SDA falling time configurable") Acked-by: Romain Baeriswyl Signed-off-by: Wolfram Sang Cc: stable@kernel.org --- Documentation/devicetree/bindings/i2c/i2c-designware.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/devicetree/bindings/i2c') diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index 5199b0c8cf7a..fee26dc3e858 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt @@ -14,10 +14,10 @@ Optional properties : - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. This option is only supported in hardware blocks version 1.11a or newer. - - i2c-scl-falling-time : should contain the SCL falling time in nanoseconds. + - i2c-scl-falling-time-ns : should contain the SCL falling time in nanoseconds. This value which is by default 300ns is used to compute the tLOW period. - - i2c-sda-falling-time : should contain the SDA falling time in nanoseconds. + - i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds. This value which is by default 300ns is used to compute the tHIGH period. Example : -- cgit v1.2.3