diff options
author | Pierre-Yves MORDRET <pierre-yves.mordret@st.com> | 2018-04-11 15:24:57 +0200 |
---|---|---|
committer | Wolfram Sang <wsa@the-dreams.de> | 2018-04-30 10:39:28 +0200 |
commit | 7ecc8cfde553b92f897bd60b21bf53de9277e3aa (patch) | |
tree | 1c40fbd2ce361f6956f8721d26fce355b0947cbd /drivers/i2c | |
parent | bb8822cbbc5334dc89b7415dbdc6d51421e74773 (diff) |
i2c: i2c-stm32f7: Add DMA support
This patch adds DMA support for i2c-stm32f7 driver
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/Makefile | 3 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-stm32f7.c | 214 |
2 files changed, 196 insertions, 21 deletions
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 189e34ba050f..5a869144a0c5 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -94,7 +94,8 @@ obj-$(CONFIG_I2C_SIRF) += i2c-sirf.o obj-$(CONFIG_I2C_SPRD) += i2c-sprd.o obj-$(CONFIG_I2C_ST) += i2c-st.o obj-$(CONFIG_I2C_STM32F4) += i2c-stm32f4.o -obj-$(CONFIG_I2C_STM32F7) += i2c-stm32f7.o +i2c-stm32f7-drv-objs := i2c-stm32f7.o i2c-stm32.o +obj-$(CONFIG_I2C_STM32F7) += i2c-stm32f7-drv.o obj-$(CONFIG_I2C_STU300) += i2c-stu300.o obj-$(CONFIG_I2C_SUN6I_P2WI) += i2c-sun6i-p2wi.o obj-$(CONFIG_I2C_SYNQUACER) += i2c-synquacer.o diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 0b81b5dc2eda..63ea71c5762f 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -47,6 +47,8 @@ /* STM32F7 I2C control 1 */ #define STM32F7_I2C_CR1_PECEN BIT(23) #define STM32F7_I2C_CR1_SBC BIT(16) +#define STM32F7_I2C_CR1_RXDMAEN BIT(15) +#define STM32F7_I2C_CR1_TXDMAEN BIT(14) #define STM32F7_I2C_CR1_ANFOFF BIT(12) #define STM32F7_I2C_CR1_ERRIE BIT(7) #define STM32F7_I2C_CR1_TCIE BIT(6) @@ -142,6 +144,7 @@ #define STM32F7_I2C_TIMINGR_SCLL(n) ((n) & 0xff) #define STM32F7_I2C_MAX_LEN 0xff +#define STM32F7_I2C_DMA_LEN_MIN 0x16 #define STM32F7_I2C_MAX_SLAVE 0x2 #define STM32F7_I2C_DNF_DEFAULT 0 @@ -270,6 +273,8 @@ struct stm32f7_i2c_msg { * @slave_dir: transfer direction for the current slave device * @master_mode: boolean to know in which mode the I2C is running (master or * slave) + * @dma: dma data + * @use_dma: boolean to know if dma is used in the current transfer */ struct stm32f7_i2c_dev { struct i2c_adapter adap; @@ -288,6 +293,8 @@ struct stm32f7_i2c_dev { struct i2c_client *slave_running; u32 slave_dir; bool master_mode; + struct stm32_i2c_dma *dma; + bool use_dma; }; /** @@ -599,6 +606,25 @@ static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, return 0; } +static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev) +{ + void __iomem *base = i2c_dev->base; + u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN; + + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask); +} + +static void stm32f7_i2c_dma_callback(void *arg) +{ + struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + struct device *dev = dma->chan_using->device->dev; + + stm32f7_i2c_disable_dma_req(i2c_dev); + dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir); + complete(&dma->dma_complete); +} + static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev) { struct stm32f7_i2c_timings *t = &i2c_dev->timing; @@ -653,6 +679,9 @@ static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev) struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; u32 cr2; + if (i2c_dev->use_dma) + f7_msg->count -= STM32F7_I2C_MAX_LEN; + cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2); cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK; @@ -712,6 +741,7 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; void __iomem *base = i2c_dev->base; u32 cr1, cr2; + int ret; f7_msg->addr = msg->addr; f7_msg->buf = msg->buf; @@ -753,14 +783,35 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE | STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE; - /* Clear TX/RX interrupt */ - cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE); + /* Clear DMA req and TX/RX interrupt */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE | + STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN); + + /* Configure DMA or enable RX/TX interrupt */ + i2c_dev->use_dma = false; + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) { + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + msg->flags & I2C_M_RD, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + if (!ret) + i2c_dev->use_dma = true; + else + dev_warn(i2c_dev->dev, "can't use DMA\n"); + } - /* Enable RX/TX interrupt according to msg direction */ - if (msg->flags & I2C_M_RD) - cr1 |= STM32F7_I2C_CR1_RXIE; - else - cr1 |= STM32F7_I2C_CR1_TXIE; + if (!i2c_dev->use_dma) { + if (msg->flags & I2C_M_RD) + cr1 |= STM32F7_I2C_CR1_RXIE; + else + cr1 |= STM32F7_I2C_CR1_TXIE; + } else { + if (msg->flags & I2C_M_RD) + cr1 |= STM32F7_I2C_CR1_RXDMAEN; + else + cr1 |= STM32F7_I2C_CR1_TXDMAEN; + } /* Configure Start/Repeated Start */ cr2 |= STM32F7_I2C_CR2_START; @@ -780,7 +831,7 @@ static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, struct device *dev = i2c_dev->dev; void __iomem *base = i2c_dev->base; u32 cr1, cr2; - int i; + int i, ret; f7_msg->result = 0; reinit_completion(&i2c_dev->complete); @@ -895,14 +946,35 @@ static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE | STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE; - /* Clear TX/RX interrupt */ - cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE); + /* Clear DMA req and TX/RX interrupt */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE | + STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN); + + /* Configure DMA or enable RX/TX interrupt */ + i2c_dev->use_dma = false; + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) { + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + cr2 & STM32F7_I2C_CR2_RD_WRN, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + if (!ret) + i2c_dev->use_dma = true; + else + dev_warn(i2c_dev->dev, "can't use DMA\n"); + } - /* Enable RX/TX interrupt according to msg direction */ - if (cr2 & STM32F7_I2C_CR2_RD_WRN) - cr1 |= STM32F7_I2C_CR1_RXIE; - else - cr1 |= STM32F7_I2C_CR1_TXIE; + if (!i2c_dev->use_dma) { + if (cr2 & STM32F7_I2C_CR2_RD_WRN) + cr1 |= STM32F7_I2C_CR1_RXIE; + else + cr1 |= STM32F7_I2C_CR1_TXIE; + } else { + if (cr2 & STM32F7_I2C_CR2_RD_WRN) + cr1 |= STM32F7_I2C_CR1_RXDMAEN; + else + cr1 |= STM32F7_I2C_CR1_TXDMAEN; + } /* Set Start bit */ cr2 |= STM32F7_I2C_CR2_START; @@ -921,6 +993,7 @@ static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev) struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; void __iomem *base = i2c_dev->base; u32 cr1, cr2; + int ret; cr2 = readl_relaxed(base + STM32F7_I2C_CR2); cr1 = readl_relaxed(base + STM32F7_I2C_CR1); @@ -960,6 +1033,35 @@ static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev) cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE); cr1 |= STM32F7_I2C_CR1_RXIE; + /* + * Configure DMA or enable RX/TX interrupt: + * For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use + * dma as we don't know in advance how many data will be received + */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE | + STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN); + + i2c_dev->use_dma = false; + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN && + f7_msg->size != I2C_SMBUS_BLOCK_DATA && + f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) { + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + cr2 & STM32F7_I2C_CR2_RD_WRN, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + + if (!ret) + i2c_dev->use_dma = true; + else + dev_warn(i2c_dev->dev, "can't use DMA\n"); + } + + if (!i2c_dev->use_dma) + cr1 |= STM32F7_I2C_CR1_RXIE; + else + cr1 |= STM32F7_I2C_CR1_RXDMAEN; + /* Configure Repeated Start */ cr2 |= STM32F7_I2C_CR2_START; @@ -1248,7 +1350,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; void __iomem *base = i2c_dev->base; u32 status, mask; - int ret; + int ret = IRQ_HANDLED; /* Check if the interrupt if for a slave device */ if (!i2c_dev->master_mode) { @@ -1285,8 +1387,12 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) /* Clear STOP flag */ writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR); - i2c_dev->master_mode = false; - complete(&i2c_dev->complete); + if (i2c_dev->use_dma) { + ret = IRQ_WAKE_THREAD; + } else { + i2c_dev->master_mode = false; + complete(&i2c_dev->complete); + } } /* Transfer complete */ @@ -1294,6 +1400,8 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) if (f7_msg->stop) { mask = STM32F7_I2C_CR2_STOP; stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask); + } else if (i2c_dev->use_dma) { + ret = IRQ_WAKE_THREAD; } else if (f7_msg->smbus) { stm32f7_i2c_smbus_rep_start(i2c_dev); } else { @@ -1310,6 +1418,44 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) stm32f7_i2c_reload(i2c_dev); } + return ret; +} + +static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) +{ + struct stm32f7_i2c_dev *i2c_dev = data; + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + u32 status; + int ret; + + /* + * Wait for dma transfer completion before sending next message or + * notity the end of xfer to the client + */ + ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ); + if (!ret) { + dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__); + stm32f7_i2c_disable_dma_req(i2c_dev); + dmaengine_terminate_all(dma->chan_using); + f7_msg->result = -ETIMEDOUT; + } + + status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + + if (status & STM32F7_I2C_ISR_TC) { + if (f7_msg->smbus) { + stm32f7_i2c_smbus_rep_start(i2c_dev); + } else { + i2c_dev->msg_id++; + i2c_dev->msg++; + stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg); + } + } else { + i2c_dev->master_mode = false; + complete(&i2c_dev->complete); + } + return IRQ_HANDLED; } @@ -1319,6 +1465,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; void __iomem *base = i2c_dev->base; struct device *dev = i2c_dev->dev; + struct stm32_i2c_dma *dma = i2c_dev->dma; u32 mask, status; status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); @@ -1350,6 +1497,12 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) mask = STM32F7_I2C_ALL_IRQ_MASK; stm32f7_i2c_disable_irq(i2c_dev, mask); + /* Disable dma */ + if (i2c_dev->use_dma) { + stm32f7_i2c_disable_dma_req(i2c_dev); + dmaengine_terminate_all(dma->chan_using); + } + i2c_dev->master_mode = false; complete(&i2c_dev->complete); @@ -1361,6 +1514,7 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap, { struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; unsigned long time_left; int ret; @@ -1388,6 +1542,8 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap, if (!time_left) { dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n", i2c_dev->msg->addr); + if (i2c_dev->use_dma) + dmaengine_terminate_all(dma->chan_using); ret = -ETIMEDOUT; } @@ -1404,6 +1560,7 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, { struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter); struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; struct device *dev = i2c_dev->dev; unsigned long timeout; int i, ret; @@ -1435,6 +1592,8 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, if (!timeout) { dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr); + if (i2c_dev->use_dma) + dmaengine_terminate_all(dma->chan_using); ret = -ETIMEDOUT; goto clk_free; } @@ -1608,6 +1767,7 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) u32 irq_error, irq_event, clk_rate, rise_time, fall_time; struct i2c_adapter *adap; struct reset_control *rst; + dma_addr_t phy_addr; int ret; i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); @@ -1618,6 +1778,7 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) i2c_dev->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c_dev->base)) return PTR_ERR(i2c_dev->base); + phy_addr = (dma_addr_t)res->start; irq_event = irq_of_parse_and_map(np, 0); if (!irq_event) { @@ -1664,8 +1825,11 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) i2c_dev->dev = &pdev->dev; - ret = devm_request_irq(&pdev->dev, irq_event, stm32f7_i2c_isr_event, 0, - pdev->name, i2c_dev); + ret = devm_request_threaded_irq(&pdev->dev, irq_event, + stm32f7_i2c_isr_event, + stm32f7_i2c_isr_event_thread, + IRQF_ONESHOT, + pdev->name, i2c_dev); if (ret) { dev_err(&pdev->dev, "Failed to request irq event %i\n", irq_event); @@ -1717,6 +1881,11 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) init_completion(&i2c_dev->complete); + /* Init DMA config if supported */ + i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr, + STM32F7_I2C_TXDR, + STM32F7_I2C_RXDR); + ret = i2c_add_adapter(adap); if (ret) goto clk_free; @@ -1739,6 +1908,11 @@ static int stm32f7_i2c_remove(struct platform_device *pdev) { struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + if (i2c_dev->dma) { + stm32_i2c_dma_free(i2c_dev->dma); + i2c_dev->dma = NULL; + } + i2c_del_adapter(&i2c_dev->adap); clk_unprepare(i2c_dev->clk); |