diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-axxia.c | 152 |
2 files changed, 145 insertions, 8 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index ee7f415a625a..d3023e5379ea 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -429,6 +429,7 @@ config I2C_AXXIA tristate "Axxia I2C controller" depends on ARCH_AXXIA || COMPILE_TEST default ARCH_AXXIA + select I2C_SLAVE help Say yes if you want to support the I2C bus on Axxia platforms. diff --git a/drivers/i2c/busses/i2c-axxia.c b/drivers/i2c/busses/i2c-axxia.c index ff3142b15cab..0214daa913ff 100644 --- a/drivers/i2c/busses/i2c-axxia.c +++ b/drivers/i2c/busses/i2c-axxia.c @@ -77,6 +77,40 @@ MST_STATUS_IP) #define MST_TX_BYTES_XFRD 0x50 #define MST_RX_BYTES_XFRD 0x54 +#define SLV_ADDR_DEC_CTL 0x58 +#define SLV_ADDR_DEC_GCE BIT(0) /* ACK to General Call Address from own master (loopback) */ +#define SLV_ADDR_DEC_OGCE BIT(1) /* ACK to General Call Address from external masters */ +#define SLV_ADDR_DEC_SA1E BIT(2) /* ACK to addr_1 enabled */ +#define SLV_ADDR_DEC_SA1M BIT(3) /* 10-bit addressing for addr_1 enabled */ +#define SLV_ADDR_DEC_SA2E BIT(4) /* ACK to addr_2 enabled */ +#define SLV_ADDR_DEC_SA2M BIT(5) /* 10-bit addressing for addr_2 enabled */ +#define SLV_ADDR_1 0x5c +#define SLV_ADDR_2 0x60 +#define SLV_RX_CTL 0x64 +#define SLV_RX_ACSA1 BIT(0) /* Generate ACK for writes to addr_1 */ +#define SLV_RX_ACSA2 BIT(1) /* Generate ACK for writes to addr_2 */ +#define SLV_RX_ACGCA BIT(2) /* ACK data phase transfers to General Call Address */ +#define SLV_DATA 0x68 +#define SLV_RX_FIFO 0x6c +#define SLV_FIFO_DV1 BIT(0) /* Data Valid for addr_1 */ +#define SLV_FIFO_DV2 BIT(1) /* Data Valid for addr_2 */ +#define SLV_FIFO_AS BIT(2) /* (N)ACK Sent */ +#define SLV_FIFO_TNAK BIT(3) /* Timeout NACK */ +#define SLV_FIFO_STRC BIT(4) /* First byte after start condition received */ +#define SLV_FIFO_RSC BIT(5) /* Repeated Start Condition */ +#define SLV_FIFO_STPC BIT(6) /* Stop Condition */ +#define SLV_FIFO_DV (SLV_FIFO_DV1 | SLV_FIFO_DV2) +#define SLV_INT_ENABLE 0x70 +#define SLV_INT_STATUS 0x74 +#define SLV_STATUS_RFH BIT(0) /* FIFO service */ +#define SLV_STATUS_WTC BIT(1) /* Write transfer complete */ +#define SLV_STATUS_SRS1 BIT(2) /* Slave read from addr 1 */ +#define SLV_STATUS_SRRS1 BIT(3) /* Repeated start from addr 1 */ +#define SLV_STATUS_SRND1 BIT(4) /* Read request not following start condition */ +#define SLV_STATUS_SRC1 BIT(5) /* Read canceled */ +#define SLV_STATUS_SRAT1 BIT(6) /* Slave Read timed out */ +#define SLV_STATUS_SRDRE1 BIT(7) /* Data written after timed out */ +#define SLV_READ_DUMMY 0x78 #define SCL_HIGH_PERIOD 0x80 #define SCL_LOW_PERIOD 0x84 #define SPIKE_FLTR_LEN 0x88 @@ -111,6 +145,8 @@ struct axxia_i2c_dev { struct clk *i2c_clk; u32 bus_clk_rate; bool last; + struct i2c_client *slave; + int irq; }; static void i2c_int_disable(struct axxia_i2c_dev *idev, u32 mask) @@ -276,13 +312,65 @@ static int axxia_i2c_fill_tx_fifo(struct axxia_i2c_dev *idev) return ret; } +static void axxia_i2c_slv_fifo_event(struct axxia_i2c_dev *idev) +{ + u32 fifo_status = readl(idev->base + SLV_RX_FIFO); + u8 val; + + dev_dbg(idev->dev, "slave irq fifo_status=0x%x\n", fifo_status); + + if (fifo_status & SLV_FIFO_DV1) { + if (fifo_status & SLV_FIFO_STRC) + i2c_slave_event(idev->slave, + I2C_SLAVE_WRITE_REQUESTED, &val); + + val = readl(idev->base + SLV_DATA); + i2c_slave_event(idev->slave, I2C_SLAVE_WRITE_RECEIVED, &val); + } + if (fifo_status & SLV_FIFO_STPC) { + readl(idev->base + SLV_DATA); /* dummy read */ + i2c_slave_event(idev->slave, I2C_SLAVE_STOP, &val); + } + if (fifo_status & SLV_FIFO_RSC) + readl(idev->base + SLV_DATA); /* dummy read */ +} + +static irqreturn_t axxia_i2c_slv_isr(struct axxia_i2c_dev *idev) +{ + u32 status = readl(idev->base + SLV_INT_STATUS); + u8 val; + + dev_dbg(idev->dev, "slave irq status=0x%x\n", status); + + if (status & SLV_STATUS_RFH) + axxia_i2c_slv_fifo_event(idev); + if (status & SLV_STATUS_SRS1) { + i2c_slave_event(idev->slave, I2C_SLAVE_READ_REQUESTED, &val); + writel(val, idev->base + SLV_DATA); + } + if (status & SLV_STATUS_SRND1) { + i2c_slave_event(idev->slave, I2C_SLAVE_READ_PROCESSED, &val); + writel(val, idev->base + SLV_DATA); + } + if (status & SLV_STATUS_SRC1) + i2c_slave_event(idev->slave, I2C_SLAVE_STOP, &val); + + writel(INT_SLV, idev->base + INTERRUPT_STATUS); + return IRQ_HANDLED; +} + static irqreturn_t axxia_i2c_isr(int irq, void *_dev) { struct axxia_i2c_dev *idev = _dev; + irqreturn_t ret = IRQ_NONE; u32 status; - if (!(readl(idev->base + INTERRUPT_STATUS) & INT_MST)) - return IRQ_NONE; + status = readl(idev->base + INTERRUPT_STATUS); + + if (status & INT_SLV) + ret = axxia_i2c_slv_isr(idev); + if (!(status & INT_MST)) + return ret; /* Read interrupt status bits */ status = readl(idev->base + MST_INT_STATUS); @@ -583,9 +671,58 @@ static u32 axxia_i2c_func(struct i2c_adapter *adap) return caps; } +static int axxia_i2c_reg_slave(struct i2c_client *slave) +{ + struct axxia_i2c_dev *idev = i2c_get_adapdata(slave->adapter); + u32 slv_int_mask = SLV_STATUS_RFH; + u32 dec_ctl; + + if (idev->slave) + return -EBUSY; + + idev->slave = slave; + + /* Enable slave mode as well */ + writel(GLOBAL_MST_EN | GLOBAL_SLV_EN, idev->base + GLOBAL_CONTROL); + writel(INT_MST | INT_SLV, idev->base + INTERRUPT_ENABLE); + + /* Set slave address */ + dec_ctl = SLV_ADDR_DEC_SA1E; + if (slave->flags & I2C_CLIENT_TEN) + dec_ctl |= SLV_ADDR_DEC_SA1M; + + writel(SLV_RX_ACSA1, idev->base + SLV_RX_CTL); + writel(dec_ctl, idev->base + SLV_ADDR_DEC_CTL); + writel(slave->addr, idev->base + SLV_ADDR_1); + + /* Enable interrupts */ + slv_int_mask |= SLV_STATUS_SRS1 | SLV_STATUS_SRRS1 | SLV_STATUS_SRND1; + slv_int_mask |= SLV_STATUS_SRC1; + writel(slv_int_mask, idev->base + SLV_INT_ENABLE); + + return 0; +} + +static int axxia_i2c_unreg_slave(struct i2c_client *slave) +{ + struct axxia_i2c_dev *idev = i2c_get_adapdata(slave->adapter); + + /* Disable slave mode */ + writel(GLOBAL_MST_EN, idev->base + GLOBAL_CONTROL); + writel(INT_MST, idev->base + INTERRUPT_ENABLE); + + synchronize_irq(idev->irq); + + idev->slave = NULL; + + return 0; +} + static const struct i2c_algorithm axxia_i2c_algo = { .master_xfer = axxia_i2c_xfer, .functionality = axxia_i2c_func, + .reg_slave = axxia_i2c_reg_slave, + .unreg_slave = axxia_i2c_unreg_slave, }; static const struct i2c_adapter_quirks axxia_i2c_quirks = { @@ -599,7 +736,6 @@ static int axxia_i2c_probe(struct platform_device *pdev) struct axxia_i2c_dev *idev = NULL; struct resource *res; void __iomem *base; - int irq; int ret = 0; idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL); @@ -611,10 +747,10 @@ static int axxia_i2c_probe(struct platform_device *pdev) if (IS_ERR(base)) return PTR_ERR(base); - irq = platform_get_irq(pdev, 0); - if (irq < 0) { + idev->irq = platform_get_irq(pdev, 0); + if (idev->irq < 0) { dev_err(&pdev->dev, "missing interrupt resource\n"); - return irq; + return idev->irq; } idev->i2c_clk = devm_clk_get(&pdev->dev, "i2c"); @@ -643,10 +779,10 @@ static int axxia_i2c_probe(struct platform_device *pdev) goto error_disable_clk; } - ret = devm_request_irq(&pdev->dev, irq, axxia_i2c_isr, 0, + ret = devm_request_irq(&pdev->dev, idev->irq, axxia_i2c_isr, 0, pdev->name, idev); if (ret) { - dev_err(&pdev->dev, "failed to claim IRQ%d\n", irq); + dev_err(&pdev->dev, "failed to claim IRQ%d\n", idev->irq); goto error_disable_clk; } |