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-rw-r--r--drivers/i2c/busses/Kconfig1
-rw-r--r--drivers/i2c/busses/i2c-axxia.c152
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;
}