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Subject[PATCH v2 2/4] Added I2C_SLAVE as a dependency to I2C_DESIGNWARE_CORE Enable _slave() mode Review of the pm_runtime...() methods and cleaning
Date
From: Luis Oliveira <lolivei@synopsys.com>

Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
---
drivers/i2c/busses/Kconfig | 3 +-
drivers/i2c/busses/i2c-designware-core.c | 180 ++++++++++++++++++++++++++--
drivers/i2c/busses/i2c-designware-core.h | 6 +
drivers/i2c/busses/i2c-designware-platdrv.c | 33 ++++-
4 files changed, 212 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 6d94e2e..f93ad70 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -470,10 +470,11 @@ config I2C_DESIGNWARE_CORE
config I2C_DESIGNWARE_PLATFORM
tristate "Synopsys DesignWare Platform"
select I2C_DESIGNWARE_CORE
+ select I2C_SLAVE
depends on (ACPI && COMMON_CLK) || !ACPI
help
If you say yes to this option, support will be included for the
- Synopsys DesignWare I2C adapter. Only master mode is supported.
+ Synopsys DesignWare I2C adapter.

This driver can also be built as a module. If so, the module
will be called i2c-designware-platform.
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index cc38329..71a377e 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -37,6 +37,7 @@
*/
#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
@@ -92,10 +93,16 @@

#define DW_IC_INTR_MASTER_MASK (DW_IC_INTR_DEFAULT_MASK | \
DW_IC_INTR_TX_EMPTY)
-
+
+#define DW_IC_INTR_SLAVE_MASK (DW_IC_INTR_DEFAULT_MASK | \
+ 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_MASTER_ACTIVITY BIT(5)
+#define DW_IC_STATUS_SLAVE_ACTIVITY BIT(6)

#define DW_IC_ERR_TX_ABRT 0x1

@@ -130,6 +137,9 @@
#define ABRT_10B_RD_NORSTRT 10
#define ABRT_MASTER_DIS 11
#define ARB_LOST 12
+#define ABRT_SLAVE_FLUSH_TXFIFO 13
+#define ABRT_SLAVE_ARBLOST 14
+#define ABRT_SLAVE_RD_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)
@@ -142,6 +152,9 @@
#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_SLAVE_RD_INTX (1UL << ABRT_SLAVE_RD_INTX)
+#define DW_IC_RX_ABRT_SLAVE_ARBLOST (1UL << ABRT_SLAVE_ARBLOST)
+#define DW_IC_RX_ABRT_SLAVE_FLUSH_TXFIFO (1UL << ABRT_SLAVE_FLUSH_TXFIFO)

#define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
DW_IC_TX_ABRT_10ADDR1_NOACK | \
@@ -172,6 +185,12 @@ static char *abort_sources[] = {
"trying to use disabled adapter",
[ARB_LOST] =
"lost arbitration",
+ [ABRT_SLAVE_FLUSH_TXFIFO] =
+ "read command so flush old data in the TX FIFO",
+ [ABRT_SLAVE_ARBLOST] =
+ "slave lost the bus while transmitting data to a remote master",
+ [ABRT_SLAVE_RD_INTX] =
+ "slave request for data to be transmitted and",
};

static u32 dw_readl(struct dw_i2c_dev *dev, int offset)
@@ -214,6 +233,17 @@ static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
}

+static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
+{
+ /* 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_SLAVE_MASK, DW_IC_INTR_MASK);
+}
+
static u32
i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
{
@@ -447,6 +477,8 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
if ((dev->master_cfg & DW_IC_CON_MASTER) &&
(dev->master_cfg & DW_IC_CON_SLAVE_DISABLE))
i2c_dw_configure_fifo_master(dev);
+ else
+ i2c_dw_configure_fifo_slave(dev);

i2c_dw_release_lock(dev);

@@ -785,9 +817,59 @@ static u32 i2c_dw_func(struct i2c_adapter *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_get_sync(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_put(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)
@@ -821,8 +903,6 @@ 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
@@ -849,6 +929,84 @@ 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_irq_handler_slave(struct dw_i2c_dev *dev )
+{
+ u32 raw_stat, stat, enabled;
+ u8 val, slave_activity;
+
+ 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);
+ slave_activity = ((dw_readl(dev,DW_IC_STATUS) &
+ DW_IC_STATUS_SLAVE_ACTIVITY)>>6);
+
+ dev_dbg(dev->dev,
+ "%s: %#x SLAVE_ACTV=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
+ __func__, enabled, slave_activity, 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))
+ i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
+
+ if (slave_activity) {
+ 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);
+ }
+ dw_readl(dev, DW_IC_CLR_RD_REQ);
+ stat = i2c_dw_read_clear_intrbits(dev);
+ }
+ else {
+ 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, 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);
+ stat = i2c_dw_read_clear_intrbits(dev);
+
+ return true;
+ }
+
+ 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);
+ }
+ else {
+ i2c_slave_event(dev->slave, I2C_SLAVE_STOP , &val);
+ stat = i2c_dw_read_clear_intrbits(dev);
+ }
+
+ if (stat & DW_IC_INTR_TX_OVER) {
+ dw_readl(dev, DW_IC_CLR_TX_OVER);
+ return true;
+ }
+
+ return true;
+}

static bool i2c_dw_irq_handler_master(struct dw_i2c_dev *dev )
{
@@ -910,14 +1068,20 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
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);
if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
return IRQ_NONE;
-
+
+ if (!(mode & DW_IC_CON_MASTER) && !(mode & DW_IC_CON_SLAVE_DISABLE)) {
+ stat = i2c_dw_read_clear_intrbits(dev);
+ if (!i2c_dw_irq_handler_slave(dev))
+ return IRQ_NONE;
+ } else {
if(i2c_dw_irq_handler_master(dev))
return IRQ_HANDLED;
-
+ }
+
complete(&dev->cmd_complete);
return IRQ_HANDLED;
}
@@ -984,7 +1148,9 @@ 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..de5e4a0 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


/**
@@ -80,6 +84,7 @@ struct dw_i2c_dev {
void __iomem *base;
struct completion cmd_complete;
struct clk *clk;
+ struct i2c_client *slave;
u32 (*get_clk_rate_khz) (struct dw_i2c_dev *dev);
struct dw_pci_controller *controller;
int cmd_err;
@@ -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 d5986c2..b9076da 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -161,6 +161,30 @@ static void i2c_dw_configure_master(struct platform_device *pdev)

}

+static void i2c_dw_configure_slave(struct platform_device *pdev)
+{
+ struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+
+ 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;
+ }
+}
+
static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
{
if (IS_ERR(i_dev->clk))
@@ -181,6 +205,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
struct resource *mem;
int irq, r;
u32 acpi_speed, ht = 0;
+ bool is_slave = false;

irq = platform_get_irq(pdev, 0);
if (irq < 0)
@@ -213,6 +238,7 @@ 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);
+ is_slave = device_property_read_bool(&pdev->dev, "isslave");
}

acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
@@ -244,8 +270,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;
-
- i2c_dw_configure_master(pdev);
+
+ if (is_slave)
+ i2c_dw_configure_slave(pdev);
+ else
+ i2c_dw_configure_master(pdev);

dev->clk = devm_clk_get(&pdev->dev, NULL);
if (!i2c_dw_plat_prepare_clk(dev, true)) {
--
2.10.1

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