[PATCH v3 4/5] i2c: designware: Add slave mode as separated driver

From: Luis Oliveira
Date: Fri Nov 18 2016 - 06:22:25 EST


- Slave mode selected by compatibility string in platform module
- Changes in Makefile to compile i2c-designware-core with slave functions

Signed-off-by: Luis Oliveira <lolivei@xxxxxxxxxxxx>
---
Changes V2->V3: (Andy Shevchenko)
- slave code in a separated driver as suggested by Wolfram Sang
- changes in Makefile for compilation purposes

drivers/i2c/busses/Makefile | 2 +-
drivers/i2c/busses/i2c-designware-platdrv.c | 69 ++++-
drivers/i2c/busses/i2c-designware-slave.c | 445 ++++++++++++++++++++++++++++
3 files changed, 507 insertions(+), 9 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-designware-slave.c

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index fc4e554..25e1778 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -40,7 +40,7 @@ obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o
obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
obj-$(CONFIG_I2C_DESIGNWARE_CORE) += i2c-designware-core.o
-i2c-designware-core-objs := i2c-designware-src.o i2c-designware-master.o
+i2c-designware-core-objs := i2c-designware-src.o i2c-designware-slave.o i2c-designware-master.o
obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM) += i2c-designware-platform.o
i2c-designware-platform-objs := i2c-designware-platdrv.o
i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index f4e28ac..7beb0a2 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -160,6 +160,30 @@ 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;
+ break;
+ 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))
@@ -244,7 +268,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;

- i2c_dw_configure_master(pdev);
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "snps,designware-i2c-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)) {
@@ -257,7 +285,13 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
}

if (!dev->tx_fifo_depth) {
- u32 param1 = i2c_dw_read_comp_param(dev);
+ u32 param1;
+
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "snps,designware-i2c-slave"))
+ param1 = i2c_dw_read_comp_param_slave(dev);
+ else
+ param1 = i2c_dw_read_comp_param(dev);

dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
@@ -278,8 +312,12 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
}
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "snps,designware-i2c-slave"))
+ r = i2c_dw_probe_slave(dev);
+ else
+ r = i2c_dw_probe(dev);

- r = i2c_dw_probe(dev);
if (r && !dev->pm_runtime_disabled)
pm_runtime_disable(&pdev->dev);

@@ -291,10 +329,13 @@ static int dw_i2c_plat_remove(struct platform_device *pdev)
struct dw_i2c_dev *dev = platform_get_drvdata(pdev);

pm_runtime_get_sync(&pdev->dev);
-
i2c_del_adapter(&dev->adapter);

- i2c_dw_disable(dev);
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "snps,designware-i2c-slave"))
+ i2c_dw_disable_slave(dev);
+ else
+ i2c_dw_disable(dev);

pm_runtime_dont_use_autosuspend(&pdev->dev);
pm_runtime_put_sync(&pdev->dev);
@@ -307,6 +348,9 @@ static int dw_i2c_plat_remove(struct platform_device *pdev)
#ifdef CONFIG_OF
static const struct of_device_id dw_i2c_of_match[] = {
{ .compatible = "snps,designware-i2c", },
+#ifndef CONFIG_ACPI
+ { .compatible = "snps,designware-i2c-slave", },
+#endif
{},
};
MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
@@ -334,7 +378,11 @@ static int dw_i2c_plat_suspend(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

- i2c_dw_disable(i_dev);
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "snps,designware-i2c-slave"))
+ i2c_dw_disable_slave(i_dev);
+ else
+ i2c_dw_disable(i_dev);
i2c_dw_plat_prepare_clk(i_dev, false);

return 0;
@@ -347,8 +395,13 @@ static int dw_i2c_plat_resume(struct device *dev)

i2c_dw_plat_prepare_clk(i_dev, true);

- if (!i_dev->pm_runtime_disabled)
- i2c_dw_init(i_dev);
+ if (!i_dev->pm_runtime_disabled) {
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "snps,designware-i2c-slave"))
+ i2c_dw_init_slave(i_dev);
+ else
+ i2c_dw_init(i_dev);
+ }

return 0;
}
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
new file mode 100644
index 0000000..6b0db3b
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -0,0 +1,445 @@
+/*
+ * Synopsys DesignWare I2C adapter driver (master only).
+ *
+ * Based on the TI DAVINCI I2C adapter driver.
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ * Copyright (C) 2009 Provigent Ltd.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include "i2c-designware-core.h"
+
+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);
+}
+
+/**
+ * i2c_dw_init_slave() - initialize the designware i2c slave hardware
+ * @dev: device private data
+ *
+ * This functions configures and enables the I2C.
+ * This function is called during I2C init function, and in case of timeout at
+ * run time.
+ */
+int i2c_dw_init_slave(struct dw_i2c_dev *dev)
+{
+ u32 hcnt, lcnt;
+ u32 reg, comp_param1;
+ u32 sda_falling_time, scl_falling_time;
+ int ret;
+
+ ret = i2c_dw_acquire_lock(dev);
+ if (ret)
+ return ret;
+
+ reg = dw_readl(dev, DW_IC_COMP_TYPE);
+ if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
+ /* Configure register endianness access */
+ dev->accessor_flags |= ACCESS_SWAP;
+ } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
+ /* 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);
+ i2c_dw_release_lock(dev);
+ return -ENODEV;
+ }
+
+ comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
+
+ /* Disable the adapter */
+ __i2c_dw_enable_and_wait(dev, false);
+
+ /* set standard and fast speed deviders for high/low periods */
+ sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
+ scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
+
+ /* Set SCL timing parameters for standard-mode */
+ if (dev->ss_hcnt && dev->ss_lcnt) {
+ hcnt = dev->ss_hcnt;
+ lcnt = dev->ss_lcnt;
+ } else {
+ hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
+ 4000, /* tHD;STA = tHIGH = 4.0 us */
+ sda_falling_time,
+ 0, /* 0: DW default, 1: Ideal */
+ 0); /* No offset */
+ lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
+ 4700, /* tLOW = 4.7 us */
+ scl_falling_time,
+ 0); /* No offset */
+ }
+ dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
+ dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
+ dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+
+ /* Set SCL timing parameters for fast-mode or fast-mode plus */
+ if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
+ hcnt = dev->fp_hcnt;
+ lcnt = dev->fp_lcnt;
+ } else if (dev->fs_hcnt && dev->fs_lcnt) {
+ hcnt = dev->fs_hcnt;
+ lcnt = dev->fs_lcnt;
+ } else {
+ hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
+ 600, /* tHD;STA = tHIGH = 0.6 us */
+ sda_falling_time,
+ 0, /* 0: DW default, 1: Ideal */
+ 0); /* No offset */
+ lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
+ 1300, /* tLOW = 1.3 us */
+ scl_falling_time,
+ 0); /* No offset */
+ }
+ dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
+ dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
+ dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+
+ if ((dev->slave_cfg & DW_IC_CON_SPEED_MASK) ==
+ DW_IC_CON_SPEED_HIGH) {
+ if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
+ != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
+ dev_err(dev->dev, "High Speed not supported!\n");
+ dev->slave_cfg &= ~DW_IC_CON_SPEED_MASK;
+ dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
+ } else if (dev->hs_hcnt && dev->hs_lcnt) {
+ hcnt = dev->hs_hcnt;
+ lcnt = dev->hs_lcnt;
+ dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
+ dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
+ dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
+ hcnt, lcnt);
+ }
+ }
+
+ /* Configure SDA Hold Time if required */
+ reg = dw_readl(dev, DW_IC_COMP_VERSION);
+ reg = dw_readl(dev, DW_IC_COMP_VERSION);
+ if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
+ if (!dev->sda_hold_time) {
+ /* Keep previous hold time setting if no one set it */
+ dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
+ }
+ /*
+ * Workaround for avoiding TX arbitration lost in case I2C
+ * slave pulls SDA down "too quickly" after falling egde of
+ * SCL by enabling non-zero SDA RX hold. Specification says it
+ * extends incoming SDA low to high transition while SCL is
+ * high but it apprears to help also above issue.
+ */
+ if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
+ dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
+ dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
+ } else {
+ dev_warn(dev->dev,
+ "Hardware too old to adjust SDA hold time.\n");
+ }
+
+ i2c_dw_configure_fifo_slave(dev);
+ i2c_dw_release_lock(dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_dw_init_slave);
+
+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);
+ 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);
+
+ i2c_dw_disable_int_slave(dev);
+ i2c_dw_disable_slave(dev);
+ dev->slave = NULL;
+
+ return 0;
+}
+
+static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
+{
+ u32 stat;
+
+ /*
+ * The IC_INTR_STAT register just indicates "enabled" interrupts.
+ * Ths unmasked raw version of interrupt status bits are available
+ * in the IC_RAW_INTR_STAT register.
+ *
+ * That is,
+ * stat = dw_readl(IC_INTR_STAT);
+ * equals to,
+ * stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
+ *
+ * The raw version might be useful for debugging purposes.
+ */
+ stat = dw_readl(dev, DW_IC_INTR_STAT);
+
+ /*
+ * Do not use the IC_CLR_INTR register to clear interrupts, or
+ * you'll miss some interrupts, triggered during the period from
+ * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
+ *
+ * Instead, use the separately-prepared IC_CLR_* registers.
+ */
+ if (stat & DW_IC_INTR_RX_UNDER)
+ dw_readl(dev, DW_IC_CLR_RX_UNDER);
+ if (stat & DW_IC_INTR_RX_OVER)
+ 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_TX_ABRT) {
+ /*
+ * The IC_TX_ABRT_SOURCE register is cleared whenever
+ * the IC_CLR_TX_ABRT is read. Preserve it beforehand.
+ */
+ dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
+ dw_readl(dev, DW_IC_CLR_TX_ABRT);
+ }
+ if (stat & DW_IC_INTR_RX_DONE)
+ dw_readl(dev, DW_IC_CLR_RX_DONE);
+ if (stat & DW_IC_INTR_ACTIVITY)
+ dw_readl(dev, DW_IC_CLR_ACTIVITY);
+ if (stat & DW_IC_INTR_STOP_DET)
+ dw_readl(dev, DW_IC_CLR_STOP_DET);
+ if (stat & DW_IC_INTR_START_DET)
+ dw_readl(dev, DW_IC_CLR_START_DET);
+ if (stat & DW_IC_INTR_GEN_CALL)
+ dw_readl(dev, DW_IC_CLR_GEN_CALL);
+
+ return stat;
+}
+
+/*
+ * 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_slave(dev);
+ } else {
+ dw_readl(dev, DW_IC_CLR_RD_REQ);
+ dw_readl(dev, DW_IC_CLR_RX_UNDER);
+ stat = i2c_dw_read_clear_intrbits_slave(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_slave(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_slave(dev);
+ }
+
+ if (stat & DW_IC_INTR_TX_OVER) {
+ dw_readl(dev, DW_IC_CLR_TX_OVER);
+ return true;
+ }
+ return true;
+}
+
+static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id)
+{
+ struct dw_i2c_dev *dev = dev_id;
+ 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);
+ if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
+ return IRQ_NONE;
+
+ stat = i2c_dw_read_clear_intrbits_slave(dev);
+ if (!i2c_dw_irq_handler_slave(dev))
+ return IRQ_NONE;
+
+ complete(&dev->cmd_complete);
+ return IRQ_HANDLED;
+}
+
+static struct i2c_algorithm i2c_dw_algo = {
+ .functionality = i2c_dw_func,
+ .reg_slave = i2c_dw_reg_slave,
+ .unreg_slave = i2c_dw_unreg_slave,
+};
+
+void i2c_dw_disable_slave(struct dw_i2c_dev *dev)
+{
+ /* Disable controller */
+ __i2c_dw_enable_and_wait(dev, false);
+
+ /* Disable all interupts */
+ dw_writel(dev, 0, DW_IC_INTR_MASK);
+ dw_readl(dev, DW_IC_CLR_INTR);
+}
+EXPORT_SYMBOL_GPL(i2c_dw_disable_slave);
+
+void i2c_dw_disable_int_slave(struct dw_i2c_dev *dev)
+{
+ dw_writel(dev, 0, DW_IC_INTR_MASK);
+}
+EXPORT_SYMBOL_GPL(i2c_dw_disable_int_slave);
+
+u32 i2c_dw_read_comp_param_slave(struct dw_i2c_dev *dev)
+{
+ return dw_readl(dev, DW_IC_COMP_PARAM_1);
+}
+EXPORT_SYMBOL_GPL(i2c_dw_read_comp_param_slave);
+
+int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
+{
+ struct i2c_adapter *adap = &dev->adapter;
+ int r;
+
+ init_completion(&dev->cmd_complete);
+
+ r = i2c_dw_init_slave(dev);
+ if (r)
+ return r;
+
+ r = i2c_dw_acquire_lock(dev);
+ if (r)
+ return r;
+
+ i2c_dw_release_lock(dev);
+ snprintf(adap->name, sizeof(adap->name),
+ "Synopsys DesignWare I2C Slave adapter");
+ adap->retries = 3;
+ adap->algo = &i2c_dw_algo;
+ adap->dev.parent = dev->dev;
+ i2c_set_adapdata(adap, dev);
+
+ r = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr_slave,
+ IRQF_SHARED | IRQF_COND_SUSPEND,
+ dev_name(dev->dev), dev);
+ if (r) {
+ dev_err(dev->dev, "failure requesting irq %i: %d\n",
+ dev->irq, r);
+ return r;
+ }
+ /*
+ * Increment PM usage count during adapter registration in order to
+ * avoid possible spurious runtime suspend when adapter device is
+ * registered to the device core and immediate resume in case bus has
+ * registered I2C slaves that do I2C transfers in their probe.
+ */
+ pm_runtime_get_noresume(dev->dev);
+ r = i2c_add_numbered_adapter(adap);
+ if (r)
+ dev_err(dev->dev, "failure adding adapter: %d\n", r);
+ pm_runtime_put_noidle(dev->dev);
+
+ return r;
+}
+EXPORT_SYMBOL_GPL(i2c_dw_probe_slave);
+
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus slave adapter");
+MODULE_LICENSE("GPL");
--
2.10.2