From: Luis Oliveira <lolivei@xxxxxxxxxxxx>
Add support in existing I2C Synopsys Designware Core driver for I2C slave mode.
Signed-off-by: Luis Oliveira <lolivei@xxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-core.c | 250 +++++++++++++++++++++++++---
drivers/i2c/busses/i2c-designware-core.h | 8 +-
drivers/i2c/busses/i2c-designware-platdrv.c | 47 ++++--
3 files changed, 271 insertions(+), 34 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 1fe93c4..c873a0c 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -21,6 +21,7 @@
* ----------------------------------------------------------------------------
*
*/
+
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/err.h>
@@ -37,6 +38,7 @@
*/
#define DW_IC_CON 0x0
#define DW_IC_TAR 0x4
+#define DW_IC_SAR 0x8
#define DW_IC_DATA_CMD 0x10
#define DW_IC_SS_SCL_HCNT 0x14
#define DW_IC_SS_SCL_LCNT 0x18
@@ -85,15 +87,27 @@
#define DW_IC_INTR_STOP_DET 0x200
#define DW_IC_INTR_START_DET 0x400
#define DW_IC_INTR_GEN_CALL 0x800
-
-#define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
- DW_IC_INTR_TX_EMPTY | \
- DW_IC_INTR_TX_ABRT | \
- DW_IC_INTR_STOP_DET)
+#define DW_IC_INTR_RESTART_DET 0x1000
+
+#define DW_IC_INTR_MST_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
+ DW_IC_INTR_TX_EMPTY | \
+ DW_IC_INTR_TX_ABRT | \
+ DW_IC_INTR_STOP_DET | \
+ DW_IC_INTR_RX_DONE | \
+ DW_IC_INTR_RX_UNDER | \
+ DW_IC_INTR_RD_REQ)
+
+ #define DW_IC_INTR_SLV_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
+ DW_IC_INTR_STOP_DET | \
+ DW_IC_INTR_TX_ABRT | \
+ DW_IC_INTR_RX_DONE | \
+ DW_IC_INTR_RX_UNDER | \
+ DW_IC_INTR_RD_REQ)
#define DW_IC_STATUS_ACTIVITY 0x1
#define DW_IC_STATUS_TFE BIT(2)
#define DW_IC_STATUS_MST_ACTIVITY BIT(5)
+#define DW_IC_STATUS_SLV_ACTIVITY BIT(6)
#define DW_IC_ERR_TX_ABRT 0x1
@@ -107,7 +121,7 @@
*/
#define STATUS_IDLE 0x0
#define STATUS_WRITE_IN_PROGRESS 0x1
-#define STATUS_READ_IN_PROGRESS 0x2
+#define STATUS_READ_IN_PROGRESS 0x2
#define TIMEOUT 20 /* ms */
@@ -128,6 +142,9 @@
#define ABRT_10B_RD_NORSTRT 10
#define ABRT_MASTER_DIS 11
#define ARB_LOST 12
+#define ABRT_SLVFLUSH_TXFIFO 13
+#define ABRT_SLV_ARBLOST 14
+#define ABRT_SLVRD_INTX 15
#define DW_IC_TX_ABRT_7B_ADDR_NOACK (1UL << ABRT_7B_ADDR_NOACK)
#define DW_IC_TX_ABRT_10ADDR1_NOACK (1UL << ABRT_10ADDR1_NOACK)
@@ -140,6 +157,9 @@
#define DW_IC_TX_ABRT_10B_RD_NORSTRT (1UL << ABRT_10B_RD_NORSTRT)
#define DW_IC_TX_ABRT_MASTER_DIS (1UL << ABRT_MASTER_DIS)
#define DW_IC_TX_ARB_LOST (1UL << ARB_LOST)
+#define DW_IC_RX_ABRT_SLVRD_INTX (1UL << ABRT_SLVRD_INTX)
+#define DW_IC_RX_ABRT_SLV_ARBLOST (1UL << ABRT_SLV_ARBLOST)
+#define DW_IC_RX_ABRT_SLVFLUSH_TXFIFO (1UL << ABRT_SLVFLUSH_TXFIFO)
#define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
DW_IC_TX_ABRT_10ADDR1_NOACK | \
@@ -170,6 +190,12 @@ static char *abort_sources[] = {
"trying to use disabled adapter",
[ARB_LOST] =
"lost arbitration",
+ [ABRT_SLVFLUSH_TXFIFO] =
+ "read command so flush old data in the TX FIFO",
+ [ABRT_SLV_ARBLOST] =
+ "slave lost the bus while transmitting data to a remote master",
+ [ABRT_SLVRD_INTX] =
+ "slave request for data to be transmitted and",
};
static u32 dw_readl(struct dw_i2c_dev *dev, int offset)
@@ -317,7 +343,7 @@ static void i2c_dw_release_lock(struct dw_i2c_dev *dev)
}
/**
- * i2c_dw_init() - initialize the designware i2c master hardware
+ * i2c_dw_init() - initialize the designware i2c hardware
* @dev: device private data
*
* This functions configures and enables the I2C master.
@@ -343,8 +369,8 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
/* Configure register access mode 16bit */
dev->accessor_flags |= ACCESS_16BIT;
} else if (reg != DW_IC_COMP_TYPE_VALUE) {
- dev_err(dev->dev, "Unknown Synopsys component type: "
- "0x%08x\n", reg);
+ dev_err(dev->dev, "Unknown Synopsys component type: 0x%08x\n",
+ reg);
i2c_dw_release_lock(dev);
return -ENODEV;
}
@@ -431,12 +457,30 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
"Hardware too old to adjust SDA hold time.\n");
}
- /* Configure Tx/Rx FIFO threshold levels */
- dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
- dw_writel(dev, 0, DW_IC_RX_TL);
-
- /* configure the i2c master */
- dw_writel(dev, dev->master_cfg , DW_IC_CON);
+ if ((dev->master_cfg & DW_IC_CON_MASTER) &&
+ (dev->master_cfg & DW_IC_CON_SLAVE_DISABLE)) {
+ /* IF master */
+
+ /* Configure Tx/Rx FIFO threshold levels */
+ dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
+ dw_writel(dev, 0, DW_IC_RX_TL);
+
+ /* configure the i2c master */
+ dw_writel(dev, dev->master_cfg, DW_IC_CON);
+ dw_writel(dev, DW_IC_INTR_MST_DEFAULT_MASK, DW_IC_INTR_MASK);
+ } else if (!(dev->master_cfg & DW_IC_CON_MASTER) &&
+ !(dev->master_cfg & DW_IC_CON_SLAVE_DISABLE)) {
+ /*IF slave */
+
+ /* Configure Tx/Rx FIFO threshold levels */
+ dw_writel(dev, 0, DW_IC_TX_TL);
+ dw_writel(dev, 0, DW_IC_RX_TL);
+
+ /* configure the i2c slave */
+ dw_writel(dev, dev->slave_cfg, DW_IC_CON);
+ dw_writel(dev, DW_IC_INTR_SLV_DEFAULT_MASK, DW_IC_INTR_MASK);
+ } else
+ return -EAGAIN;
i2c_dw_release_lock(dev);
@@ -520,7 +564,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
/* Clear and enable interrupts */
dw_readl(dev, DW_IC_CLR_INTR);
- dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK);
+ dw_writel(dev, DW_IC_INTR_MST_DEFAULT_MASK, DW_IC_INTR_MASK);
}
/*
@@ -540,7 +584,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
u8 *buf = dev->tx_buf;
bool need_restart = false;
- intr_mask = DW_IC_INTR_DEFAULT_MASK;
+ intr_mask = DW_IC_INTR_MST_DEFAULT_MASK;
for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
/*
@@ -772,12 +816,64 @@ done_nolock:
static u32 i2c_dw_func(struct i2c_adapter *adap)
{
struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+
return dev->functionality;
}
+static int i2c_dw_reg_slave(struct i2c_client *slave)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(slave->adapter);
+
+ if (dev->slave)
+ return -EBUSY;
+ if (slave->flags & I2C_CLIENT_TEN)
+ return -EAFNOSUPPORT;
+ /* set slave address in the IC_SAR register,
+ * the address to which the DW_apb_i2c responds
+ */
+
+ __i2c_dw_enable(dev, false);
+
+ dw_writel(dev, slave->addr, DW_IC_SAR);
+
+ pm_runtime_forbid(dev->dev);
+
+ dev->slave = slave;
+
+ __i2c_dw_enable(dev, true);
+
+ dev->cmd_err = 0;
+ dev->msg_write_idx = 0;
+ dev->msg_read_idx = 0;
+ dev->msg_err = 0;
+ dev->status = STATUS_IDLE;
+ dev->abort_source = 0;
+ dev->rx_outstanding = 0;
+
+ return 0;
+}
+
+static int i2c_dw_unreg_slave(struct i2c_client *slave)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(slave->adapter);
+
+ WARN_ON(!dev->slave);
+
+ i2c_dw_disable_int(dev);
+ i2c_dw_disable(dev);
+
+ dev->slave = NULL;
+
+ pm_runtime_allow(dev->dev);
+
+ return 0;
+}
+
static struct i2c_algorithm i2c_dw_algo = {
.master_xfer = i2c_dw_xfer,
.functionality = i2c_dw_func,
+ .reg_slave = i2c_dw_reg_slave,
+ .unreg_slave = i2c_dw_unreg_slave,
};
static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
@@ -811,8 +907,6 @@ static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
dw_readl(dev, DW_IC_CLR_RX_OVER);
if (stat & DW_IC_INTR_TX_OVER)
dw_readl(dev, DW_IC_CLR_TX_OVER);
- if (stat & DW_IC_INTR_RD_REQ)
- dw_readl(dev, DW_IC_CLR_RD_REQ);
if (stat & DW_IC_INTR_TX_ABRT) {
/*
* The IC_TX_ABRT_SOURCE register is cleared whenever
@@ -839,19 +933,129 @@ static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
* Interrupt service routine. This gets called whenever an I2C interrupt
* occurs.
*/
+
+static bool i2c_dw_slave_irq_handler(struct dw_i2c_dev *dev)
+{
+ u32 raw_stat, stat, enabled;
+ u8 val;
+ u8 slv_act;
+
+ stat = dw_readl(dev, DW_IC_INTR_STAT);
+ enabled = dw_readl(dev, DW_IC_ENABLE);
+ raw_stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
+
+ if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY))
+ return false;
+
+ slv_act = ((dw_readl(dev, DW_IC_STATUS) &
+ DW_IC_STATUS_SLV_ACTIVITY)>>6);
+
+ dev_dbg(dev->dev,
+ "%s: %#x SLAVE_ACTV=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
+ __func__, enabled, slv_act, raw_stat, stat);
+
+ if (stat & DW_IC_INTR_START_DET)
+ dw_readl(dev, DW_IC_CLR_START_DET);
+
+ if (stat & DW_IC_INTR_ACTIVITY)
+ dw_readl(dev, DW_IC_CLR_ACTIVITY);
+
+ if (stat & DW_IC_INTR_RX_OVER)
+ dw_readl(dev, DW_IC_CLR_RX_OVER);
+
+ if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET)) {
+ dev_dbg(dev->dev, "First write\n");
+ i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
+ }
+
+ if (slv_act) {
+ dev_dbg(dev->dev, "I2C GET\n");
+
+ if (stat & DW_IC_INTR_RD_REQ) {
+ if (stat & DW_IC_INTR_RX_FULL) {
+ val = dw_readl(dev, DW_IC_DATA_CMD);
+ if (!i2c_slave_event(dev->slave,
+ I2C_SLAVE_WRITE_RECEIVED, &val)) {
+ dev_dbg(dev->dev, "Byte %X acked! ", val);
+ ;
+ }
+ dev_dbg(dev->dev, "I2C GET + add");
+ dw_readl(dev, DW_IC_CLR_RD_REQ);
+ stat = i2c_dw_read_clear_intrbits(dev);
+ } else {
+ dev_dbg(dev->dev, "I2C GET + 0x00");
+ dw_readl(dev, DW_IC_CLR_RD_REQ);
+ dw_readl(dev, DW_IC_CLR_RX_UNDER);
+ stat = i2c_dw_read_clear_intrbits(dev);
+ }
+ if (!i2c_slave_event(dev->slave,
+ I2C_SLAVE_READ_REQUESTED, &val))
+ dw_writel(dev, (0x0 << 8 | val), DW_IC_DATA_CMD);
+ }
+ }
+ if (stat & DW_IC_INTR_RX_DONE) {
+
+ if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED, &val))
+ dw_readl(dev, DW_IC_CLR_RX_DONE);
+
+ i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
+ dev_dbg(dev->dev, "Transmission Complete.");
+ stat = i2c_dw_read_clear_intrbits(dev);
+
+ goto done;
+ }
+
+ if (stat & DW_IC_INTR_RX_FULL) {
+ dev_dbg(dev->dev, "I2C SET");
+ val = dw_readl(dev, DW_IC_DATA_CMD);
+ if (!i2c_slave_event(dev->slave,
+ I2C_SLAVE_WRITE_RECEIVED, &val)) {
+ dev_dbg(dev->dev, "Byte %X acked! ", val);
+ ;
+ }
+ } else {
+ i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
+ dev_dbg(dev->dev, "Transmission Complete.");
+ stat = i2c_dw_read_clear_intrbits(dev);
+ }
+
+ if (stat & DW_IC_INTR_TX_OVER) {
+ dw_readl(dev, DW_IC_CLR_TX_OVER);
+ return true;
+ }
+done:
+ return true;
+}
+
static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
{
struct dw_i2c_dev *dev = dev_id;
- u32 stat, enabled;
+ u32 stat, enabled, mode;
enabled = dw_readl(dev, DW_IC_ENABLE);
+ mode = dw_readl(dev, DW_IC_CON);
stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
- dev_dbg(dev->dev, "%s: enabled=%#x stat=%#x\n", __func__, enabled, stat);
+
+ stat = i2c_dw_read_clear_intrbits(dev);
+
+ dev_dbg(dev->dev,
+ "%s: enabled=%#x stat=%#x\n", __func__, enabled, stat);
+
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return IRQ_NONE;
stat = i2c_dw_read_clear_intrbits(dev);
+ if (!(mode & DW_IC_CON_MASTER) && !(mode & DW_IC_CON_SLAVE_DISABLE)) {
+
+ /* slave mode*/
+ if (!i2c_dw_slave_irq_handler(dev))
+ return IRQ_NONE;
+
+ complete(&dev->cmd_complete);
+ return IRQ_HANDLED;
+ }
+
if (stat & DW_IC_INTR_TX_ABRT) {
dev->cmd_err |= DW_IC_ERR_TX_ABRT;
dev->status = STATUS_IDLE;
@@ -961,7 +1165,9 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
adap->dev.parent = dev->dev;
i2c_set_adapdata(adap, dev);
- i2c_dw_disable_int(dev);
+ if (!i2c_check_functionality(adap, I2C_FUNC_SLAVE))
+ i2c_dw_disable_int(dev);
+
r = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr,
IRQF_SHARED | IRQF_COND_SUSPEND,
dev_name(dev->dev), dev);
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 0d44d2a..5875410 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -28,9 +28,13 @@
#define DW_IC_CON_SPEED_FAST 0x4
#define DW_IC_CON_SPEED_HIGH 0x6
#define DW_IC_CON_SPEED_MASK 0x6
+#define DW_IC_CON_10BITADDR_SLAVE 0x8
#define DW_IC_CON_10BITADDR_MASTER 0x10
#define DW_IC_CON_RESTART_EN 0x20
#define DW_IC_CON_SLAVE_DISABLE 0x40
+#define DW_IC_CON_STOP_DET_IFADDRESSED 0x80
+#define DW_IC_CON_TX_EMPTY_CTRL 0x100
+#define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL 0x200
/**
@@ -80,7 +84,8 @@ struct dw_i2c_dev {
void __iomem *base;
struct completion cmd_complete;
struct clk *clk;
- u32 (*get_clk_rate_khz) (struct dw_i2c_dev *dev);
+ struct i2c_client *slave;
+ u32 (*get_clk_rate_khz)(struct dw_i2c_dev *dev);
struct dw_pci_controller *controller;
int cmd_err;
struct i2c_msg *msgs;
@@ -99,6 +104,7 @@ struct dw_i2c_dev {
struct i2c_adapter adapter;
u32 functionality;
u32 master_cfg;
+ u32 slave_cfg;
unsigned int tx_fifo_depth;
unsigned int rx_fifo_depth;
int rx_outstanding;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..cad0218 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -21,6 +21,7 @@
* ----------------------------------------------------------------------------
*
*/
+
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
@@ -158,6 +159,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
struct resource *mem;
int irq, r;
u32 acpi_speed, ht = 0;
+ bool isslave = false;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
@@ -190,6 +192,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
&dev->scl_falling_time);
device_property_read_u32(&pdev->dev, "clock-frequency",
&dev->clk_freq);
+ isslave = device_property_read_bool(&pdev->dev, "isslave");
}
acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
@@ -216,24 +219,46 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
dev->functionality =
I2C_FUNC_I2C |
- I2C_FUNC_10BIT_ADDR |
I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;
- dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
+ if (!isslave) {
+ dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN;
+ dev->functionality |= I2C_FUNC_10BIT_ADDR;
+ dev_info(&pdev->dev, "I am registed as a I2C Master!\n");
+ switch (dev->clk_freq) {
+ case 100000:
+ dev->master_cfg |= DW_IC_CON_SPEED_STD;
+ break;
+ case 3400000:
+ dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
+ break;
+ default:
+ dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+ }
+ } else {
+ dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
+ DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED |
+ DW_IC_CON_SPEED_FAST;
+
+ dev->functionality |= I2C_FUNC_SLAVE;
+ dev->functionality &= ~I2C_FUNC_10BIT_ADDR;
+ dev_info(&pdev->dev, "I am registed as a I2C Slave!\n");
+
+ switch (dev->clk_freq) {
+ case 100000:
+ dev->slave_cfg |= DW_IC_CON_SPEED_STD;
+
+ case 3400000:
+ dev->slave_cfg |= DW_IC_CON_SPEED_HIGH;
+ break;
+ default:
+ dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
- switch (dev->clk_freq) {
- case 100000:
- dev->master_cfg |= DW_IC_CON_SPEED_STD;
- break;
- case 3400000:
- dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
- break;
- default:
- dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+ }
}
dev->clk = devm_clk_get(&pdev->dev, NULL);
--
2.10.1
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