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Diffstat (limited to 'drivers/i2c/busses/i2c-axxia.c')
-rw-r--r--drivers/i2c/busses/i2c-axxia.c263
1 files changed, 179 insertions, 84 deletions
diff --git a/drivers/i2c/busses/i2c-axxia.c b/drivers/i2c/busses/i2c-axxia.c
index bf564391091f..0555eeb6903a 100644
--- a/drivers/i2c/busses/i2c-axxia.c
+++ b/drivers/i2c/busses/i2c-axxia.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* This driver implements I2C master functionality using the LSI API2C
* controller.
@@ -5,10 +6,6 @@
* NOTE: The controller has a limitation in that it can only do transfers of
* maximum 255 bytes at a time. If a larger transfer is attempted, error code
* (-EINVAL) is returned.
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
*/
#include <linux/clk.h>
#include <linux/clkdev.h>
@@ -80,6 +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
@@ -87,7 +118,7 @@
#define SDA_HOLD_TIME 0x90
/**
- * axxia_i2c_dev - I2C device context
+ * struct axxia_i2c_dev - I2C device context
* @base: pointer to register struct
* @msg: pointer to current message
* @msg_r: pointer to current read message (sequence transfer)
@@ -99,6 +130,9 @@
* @adapter: core i2c abstraction
* @i2c_clk: clock reference for i2c input clock
* @bus_clk_rate: current i2c bus clock rate
+ * @last: a flag indicating is this is last message in transfer
+ * @slave: associated &i2c_client
+ * @irq: platform device IRQ number
*/
struct axxia_i2c_dev {
void __iomem *base;
@@ -112,6 +146,9 @@ struct axxia_i2c_dev {
struct i2c_adapter adapter;
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)
@@ -130,7 +167,7 @@ static void i2c_int_enable(struct axxia_i2c_dev *idev, u32 mask)
writel(int_en | mask, idev->base + MST_INT_ENABLE);
}
-/**
+/*
* ns_to_clk - Convert time (ns) to clock cycles for the given clock frequency.
*/
static u32 ns_to_clk(u64 ns, u32 clk_mhz)
@@ -164,7 +201,7 @@ static int axxia_i2c_init(struct axxia_i2c_dev *idev)
/* Enable Master Mode */
writel(0x1, idev->base + GLOBAL_CONTROL);
- if (idev->bus_clk_rate <= 100000) {
+ if (idev->bus_clk_rate <= I2C_MAX_STANDARD_MODE_FREQ) {
/* Standard mode SCL 50/50, tSU:DAT = 250 ns */
t_high = divisor * 1 / 2;
t_low = divisor * 1 / 2;
@@ -218,17 +255,12 @@ static int i2c_m_rd(const struct i2c_msg *msg)
return (msg->flags & I2C_M_RD) != 0;
}
-static int i2c_m_ten(const struct i2c_msg *msg)
-{
- return (msg->flags & I2C_M_TEN) != 0;
-}
-
static int i2c_m_recv_len(const struct i2c_msg *msg)
{
return (msg->flags & I2C_M_RECV_LEN) != 0;
}
-/**
+/*
* axxia_i2c_empty_rx_fifo - Fetch data from RX FIFO and update SMBus block
* transfer length if this is the first byte of such a transfer.
*/
@@ -260,7 +292,7 @@ static int axxia_i2c_empty_rx_fifo(struct axxia_i2c_dev *idev)
return 0;
}
-/**
+/*
* axxia_i2c_fill_tx_fifo - Fill TX FIFO from current message buffer.
* @return: Number of bytes left to transfer.
*/
@@ -277,13 +309,65 @@ 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);
@@ -324,15 +408,14 @@ static irqreturn_t axxia_i2c_isr(int irq, void *_dev)
/* Stop completed */
i2c_int_disable(idev, ~MST_STATUS_TSS);
complete(&idev->msg_complete);
- } else if (status & MST_STATUS_SNS) {
+ } else if (status & (MST_STATUS_SNS | MST_STATUS_SS)) {
/* Transfer done */
- i2c_int_disable(idev, ~MST_STATUS_TSS);
+ int mask = idev->last ? ~0 : ~MST_STATUS_TSS;
+
+ i2c_int_disable(idev, mask);
if (i2c_m_rd(idev->msg_r) && idev->msg_xfrd_r < idev->msg_r->len)
axxia_i2c_empty_rx_fifo(idev);
complete(&idev->msg_complete);
- } else if (status & MST_STATUS_SS) {
- /* Auto/Sequence transfer done */
- complete(&idev->msg_complete);
} else if (status & MST_STATUS_TSS) {
/* Transfer timeout */
idev->msg_err = -ETIMEDOUT;
@@ -351,20 +434,10 @@ static void axxia_i2c_set_addr(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
{
u32 addr_1, addr_2;
- if (i2c_m_ten(msg)) {
- /* 10-bit address
- * addr_1: 5'b11110 | addr[9:8] | (R/nW)
- * addr_2: addr[7:0]
- */
- addr_1 = 0xF0 | ((msg->addr >> 7) & 0x06);
- if (i2c_m_rd(msg))
- addr_1 |= 1; /* Set the R/nW bit of the address */
- addr_2 = msg->addr & 0xFF;
+ if (msg->flags & I2C_M_TEN) {
+ addr_1 = i2c_10bit_addr_hi_from_msg(msg);
+ addr_2 = i2c_10bit_addr_lo_from_msg(msg);
} else {
- /* 7-bit address
- * addr_1: addr[6:0] | (R/nW)
- * addr_2: dont care
- */
addr_1 = i2c_8bit_addr_from_msg(msg);
addr_2 = 0;
}
@@ -405,6 +478,7 @@ static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
idev->msg_r = &msgs[1];
idev->msg_xfrd = 0;
idev->msg_xfrd_r = 0;
+ idev->last = true;
axxia_i2c_fill_tx_fifo(idev);
writel(CMD_SEQUENCE, idev->base + MST_COMMAND);
@@ -415,10 +489,6 @@ static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
time_left = wait_for_completion_timeout(&idev->msg_complete,
I2C_XFER_TIMEOUT);
- i2c_int_disable(idev, int_mask);
-
- axxia_i2c_empty_rx_fifo(idev);
-
if (idev->msg_err == -ENXIO) {
if (axxia_i2c_handle_seq_nak(idev))
axxia_i2c_init(idev);
@@ -438,9 +508,10 @@ static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
return idev->msg_err;
}
-static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
+static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg,
+ bool last)
{
- u32 int_mask = MST_STATUS_ERR | MST_STATUS_SNS;
+ u32 int_mask = MST_STATUS_ERR;
u32 rx_xfer, tx_xfer;
unsigned long time_left;
unsigned int wt_value;
@@ -449,6 +520,7 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
idev->msg_r = msg;
idev->msg_xfrd = 0;
idev->msg_xfrd_r = 0;
+ idev->last = last;
reinit_completion(&idev->msg_complete);
axxia_i2c_set_addr(idev, msg);
@@ -478,8 +550,13 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
if (idev->msg_err)
goto out;
- /* Start manual mode */
- writel(CMD_MANUAL, idev->base + MST_COMMAND);
+ if (!last) {
+ writel(CMD_MANUAL, idev->base + MST_COMMAND);
+ int_mask |= MST_STATUS_SNS;
+ } else {
+ writel(CMD_AUTO, idev->base + MST_COMMAND);
+ int_mask |= MST_STATUS_SS;
+ }
writel(WT_EN | wt_value, idev->base + WAIT_TIMER_CONTROL);
@@ -507,28 +584,6 @@ out:
return idev->msg_err;
}
-static int axxia_i2c_stop(struct axxia_i2c_dev *idev)
-{
- u32 int_mask = MST_STATUS_ERR | MST_STATUS_SCC | MST_STATUS_TSS;
- unsigned long time_left;
-
- reinit_completion(&idev->msg_complete);
-
- /* Issue stop */
- writel(0xb, idev->base + MST_COMMAND);
- i2c_int_enable(idev, int_mask);
- time_left = wait_for_completion_timeout(&idev->msg_complete,
- I2C_STOP_TIMEOUT);
- i2c_int_disable(idev, int_mask);
- if (time_left == 0)
- return -ETIMEDOUT;
-
- if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
- dev_warn(idev->dev, "busy after stop\n");
-
- return 0;
-}
-
/* This function checks if the msgs[] array contains messages compatible with
* Sequence mode of operation. This mode assumes there will be exactly one
* write of non-zero length followed by exactly one read of non-zero length,
@@ -558,9 +613,7 @@ axxia_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
i2c_int_enable(idev, MST_STATUS_TSS);
for (i = 0; ret == 0 && i < num; ++i)
- ret = axxia_i2c_xfer_msg(idev, &msgs[i]);
-
- axxia_i2c_stop(idev);
+ ret = axxia_i2c_xfer_msg(idev, &msgs[i], i == (num - 1));
return ret ? : i;
}
@@ -605,9 +658,58 @@ 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,
+ .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 = {
@@ -619,25 +721,20 @@ static int axxia_i2c_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
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);
if (!idev)
return -ENOMEM;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- base = devm_ioremap_resource(&pdev->dev, res);
+ base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "missing interrupt resource\n");
- return irq;
- }
+ idev->irq = platform_get_irq(pdev, 0);
+ if (idev->irq < 0)
+ return idev->irq;
idev->i2c_clk = devm_clk_get(&pdev->dev, "i2c");
if (IS_ERR(idev->i2c_clk)) {
@@ -651,7 +748,7 @@ static int axxia_i2c_probe(struct platform_device *pdev)
of_property_read_u32(np, "clock-frequency", &idev->bus_clk_rate);
if (idev->bus_clk_rate == 0)
- idev->bus_clk_rate = 100000; /* default clock rate */
+ idev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ; /* default clock rate */
ret = clk_prepare_enable(idev->i2c_clk);
if (ret) {
@@ -665,15 +762,15 @@ 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;
}
i2c_set_adapdata(&idev->adapter, idev);
- strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
+ strscpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
idev->adapter.owner = THIS_MODULE;
idev->adapter.algo = &axxia_i2c_algo;
idev->adapter.bus_recovery_info = &axxia_i2c_recovery_info;
@@ -694,14 +791,12 @@ error_disable_clk:
return ret;
}
-static int axxia_i2c_remove(struct platform_device *pdev)
+static void axxia_i2c_remove(struct platform_device *pdev)
{
struct axxia_i2c_dev *idev = platform_get_drvdata(pdev);
clk_disable_unprepare(idev->i2c_clk);
i2c_del_adapter(&idev->adapter);
-
- return 0;
}
/* Match table for of_platform binding */
generated by cgit (git 2.34.1) at 2025-12-25 12:39:02 +0000