i2c: designware: add SLAVE mode functions
- Changes in Kconfig to enable I2C_DESIGNWARE_SLAVE support - Slave functions added to core library file - Slave abort sources added to common source file - New driver: i2c-designware-slave added - Changes in the Makefile to compile the I2C_DESIGNWARE_SLAVE module when supported by the architecture. All the SLAVE flow is added but it is not enabled via platform driver. Signed-off-by: Luis Oliveira <lolivei@synopsys.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> [wsa: made a function static and one-lined a message] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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@ -483,14 +483,26 @@ config I2C_DESIGNWARE_CORE
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config I2C_DESIGNWARE_PLATFORM
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tristate "Synopsys DesignWare Platform"
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select I2C_DESIGNWARE_CORE
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select I2C_DESIGNWARE_SLAVE
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depends on (ACPI && COMMON_CLK) || !ACPI
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help
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If you say yes to this option, support will be included for the
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Synopsys DesignWare I2C adapter. Only master mode is supported.
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Synopsys DesignWare I2C adapter.
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This driver can also be built as a module. If so, the module
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will be called i2c-designware-platform.
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config I2C_DESIGNWARE_SLAVE
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bool "Synopsys DesignWare Slave"
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select I2C_SLAVE
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depends on I2C_DESIGNWARE_PLATFORM
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help
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If you say yes to this option, support will be included for the
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Synopsys DesignWare I2C slave adapter.
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This is not a standalone module, this module compiles together with
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i2c-designware-core.
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config I2C_DESIGNWARE_PCI
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tristate "Synopsys DesignWare PCI"
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depends on PCI
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@ -42,6 +42,9 @@ obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
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obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
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obj-$(CONFIG_I2C_DESIGNWARE_CORE) += i2c-designware-core.o
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i2c-designware-core-objs := i2c-designware-common.o i2c-designware-master.o
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ifeq ($(CONFIG_I2C_DESIGNWARE_SLAVE),y)
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i2c-designware-core-objs += i2c-designware-slave.o
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endif
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obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM) += i2c-designware-platform.o
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i2c-designware-platform-objs := i2c-designware-platdrv.o
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i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
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@ -56,6 +56,12 @@ static char *abort_sources[] = {
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"trying to use disabled adapter",
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[ARB_LOST] =
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"lost arbitration",
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[ABRT_SLAVE_FLUSH_TXFIFO] =
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"read command so flush old data in the TX FIFO",
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[ABRT_SLAVE_ARBLOST] =
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"slave lost the bus while transmitting data to a remote master",
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[ABRT_SLAVE_RD_INTX] =
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"incorrect slave-transmitter mode configuration",
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};
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u32 dw_readl(struct dw_i2c_dev *dev, int offset)
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@ -305,9 +305,11 @@ u32 i2c_dw_func(struct i2c_adapter *adap);
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void i2c_dw_disable(struct dw_i2c_dev *dev);
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void i2c_dw_disable_int(struct dw_i2c_dev *dev);
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int i2c_dw_init(struct dw_i2c_dev *dev);
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int i2c_dw_init_slave(struct dw_i2c_dev *dev);
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extern u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev);
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extern int i2c_dw_probe(struct dw_i2c_dev *dev);
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extern int i2c_dw_probe_slave(struct dw_i2c_dev *dev);
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#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
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extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
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@ -0,0 +1,394 @@
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/*
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* Synopsys DesignWare I2C adapter driver (slave only).
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*
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* Based on the Synopsys DesignWare I2C adapter driver (master).
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*
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* Copyright (C) 2016 Synopsys Inc.
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*
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* ----------------------------------------------------------------------------
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* ----------------------------------------------------------------------------
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*
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*/
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/pm_runtime.h>
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#include "i2c-designware-core.h"
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static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
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{
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/* Configure Tx/Rx FIFO threshold levels. */
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dw_writel(dev, 0, DW_IC_TX_TL);
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dw_writel(dev, 0, DW_IC_RX_TL);
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/* Configure the I2C slave. */
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dw_writel(dev, dev->slave_cfg, DW_IC_CON);
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dw_writel(dev, DW_IC_INTR_SLAVE_MASK, DW_IC_INTR_MASK);
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}
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/**
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* i2c_dw_init_slave() - Initialize the designware i2c slave hardware
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* @dev: device private data
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*
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* This function configures and enables the I2C in slave mode.
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* This function is called during I2C init function, and in case of timeout at
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* run time.
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*/
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int i2c_dw_init_slave(struct dw_i2c_dev *dev)
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{
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u32 sda_falling_time, scl_falling_time;
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u32 reg, comp_param1;
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u32 hcnt, lcnt;
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int ret;
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ret = i2c_dw_acquire_lock(dev);
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if (ret)
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return ret;
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reg = dw_readl(dev, DW_IC_COMP_TYPE);
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if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
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/* Configure register endianness access. */
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dev->flags |= ACCESS_SWAP;
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} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
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/* Configure register access mode 16bit. */
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dev->flags |= ACCESS_16BIT;
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} else if (reg != DW_IC_COMP_TYPE_VALUE) {
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dev_err(dev->dev,
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"Unknown Synopsys component type: 0x%08x\n", reg);
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i2c_dw_release_lock(dev);
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return -ENODEV;
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}
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comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
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/* Disable the adapter. */
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__i2c_dw_enable_and_wait(dev, false);
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/* Set standard and fast speed deviders for high/low periods. */
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sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
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scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
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/* Set SCL timing parameters for standard-mode. */
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if (dev->ss_hcnt && dev->ss_lcnt) {
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hcnt = dev->ss_hcnt;
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lcnt = dev->ss_lcnt;
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} else {
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hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
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4000, /* tHD;STA = tHIGH = 4.0 us */
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sda_falling_time,
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0, /* 0: DW default, 1: Ideal */
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0); /* No offset */
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lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
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4700, /* tLOW = 4.7 us */
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scl_falling_time,
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0); /* No offset */
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}
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dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
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dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
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dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
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/* Set SCL timing parameters for fast-mode or fast-mode plus. */
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if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
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hcnt = dev->fp_hcnt;
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lcnt = dev->fp_lcnt;
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} else if (dev->fs_hcnt && dev->fs_lcnt) {
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hcnt = dev->fs_hcnt;
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lcnt = dev->fs_lcnt;
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} else {
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hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
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600, /* tHD;STA = tHIGH = 0.6 us */
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sda_falling_time,
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0, /* 0: DW default, 1: Ideal */
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0); /* No offset */
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lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
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1300, /* tLOW = 1.3 us */
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scl_falling_time,
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0); /* No offset */
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}
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dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
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dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
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dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
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if ((dev->slave_cfg & DW_IC_CON_SPEED_MASK) ==
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DW_IC_CON_SPEED_HIGH) {
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if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
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!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
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dev_err(dev->dev, "High Speed not supported!\n");
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dev->slave_cfg &= ~DW_IC_CON_SPEED_MASK;
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dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
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} else if (dev->hs_hcnt && dev->hs_lcnt) {
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hcnt = dev->hs_hcnt;
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lcnt = dev->hs_lcnt;
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dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
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dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
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dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
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hcnt, lcnt);
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}
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}
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/* Configure SDA Hold Time if required. */
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reg = dw_readl(dev, DW_IC_COMP_VERSION);
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if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
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if (!dev->sda_hold_time) {
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/* Keep previous hold time setting if no one set it. */
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dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
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}
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/*
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* Workaround for avoiding TX arbitration lost in case I2C
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* slave pulls SDA down "too quickly" after falling egde of
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* SCL by enabling non-zero SDA RX hold. Specification says it
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* extends incoming SDA low to high transition while SCL is
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* high but it apprears to help also above issue.
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*/
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if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
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dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
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dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
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} else {
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dev_warn(dev->dev,
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"Hardware too old to adjust SDA hold time.\n");
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}
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i2c_dw_configure_fifo_slave(dev);
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i2c_dw_release_lock(dev);
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return 0;
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}
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EXPORT_SYMBOL_GPL(i2c_dw_init_slave);
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static int i2c_dw_reg_slave(struct i2c_client *slave)
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{
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struct dw_i2c_dev *dev = i2c_get_adapdata(slave->adapter);
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if (dev->slave)
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return -EBUSY;
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if (slave->flags & I2C_CLIENT_TEN)
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return -EAFNOSUPPORT;
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/*
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* Set slave address in the IC_SAR register,
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* the address to which the DW_apb_i2c responds.
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*/
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__i2c_dw_enable(dev, false);
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dw_writel(dev, slave->addr, DW_IC_SAR);
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dev->slave = slave;
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__i2c_dw_enable(dev, true);
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dev->cmd_err = 0;
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dev->msg_write_idx = 0;
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dev->msg_read_idx = 0;
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dev->msg_err = 0;
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dev->status = STATUS_IDLE;
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dev->abort_source = 0;
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dev->rx_outstanding = 0;
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return 0;
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}
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static int i2c_dw_unreg_slave(struct i2c_client *slave)
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{
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struct dw_i2c_dev *dev = i2c_get_adapdata(slave->adapter);
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dev->disable_int(dev);
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dev->disable(dev);
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dev->slave = NULL;
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return 0;
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}
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static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
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{
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u32 stat;
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/*
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* The IC_INTR_STAT register just indicates "enabled" interrupts.
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* Ths unmasked raw version of interrupt status bits are available
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* in the IC_RAW_INTR_STAT register.
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*
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* That is,
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* stat = dw_readl(IC_INTR_STAT);
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* equals to,
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* stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
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*
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* The raw version might be useful for debugging purposes.
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*/
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stat = dw_readl(dev, DW_IC_INTR_STAT);
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/*
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* Do not use the IC_CLR_INTR register to clear interrupts, or
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* you'll miss some interrupts, triggered during the period from
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* dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
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*
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* Instead, use the separately-prepared IC_CLR_* registers.
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*/
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if (stat & DW_IC_INTR_TX_ABRT)
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dw_readl(dev, DW_IC_CLR_TX_ABRT);
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if (stat & DW_IC_INTR_RX_UNDER)
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dw_readl(dev, DW_IC_CLR_RX_UNDER);
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if (stat & DW_IC_INTR_RX_OVER)
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dw_readl(dev, DW_IC_CLR_RX_OVER);
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if (stat & DW_IC_INTR_TX_OVER)
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dw_readl(dev, DW_IC_CLR_TX_OVER);
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if (stat & DW_IC_INTR_RX_DONE)
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dw_readl(dev, DW_IC_CLR_RX_DONE);
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if (stat & DW_IC_INTR_ACTIVITY)
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dw_readl(dev, DW_IC_CLR_ACTIVITY);
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if (stat & DW_IC_INTR_STOP_DET)
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dw_readl(dev, DW_IC_CLR_STOP_DET);
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if (stat & DW_IC_INTR_START_DET)
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dw_readl(dev, DW_IC_CLR_START_DET);
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if (stat & DW_IC_INTR_GEN_CALL)
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dw_readl(dev, DW_IC_CLR_GEN_CALL);
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return stat;
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}
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/*
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* Interrupt service routine. This gets called whenever an I2C slave interrupt
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* occurs.
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*/
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static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
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{
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u32 raw_stat, stat, enabled;
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u8 val, slave_activity;
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stat = dw_readl(dev, DW_IC_INTR_STAT);
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enabled = dw_readl(dev, DW_IC_ENABLE);
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raw_stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
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slave_activity = ((dw_readl(dev, DW_IC_STATUS) &
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DW_IC_STATUS_SLAVE_ACTIVITY) >> 6);
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if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY))
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return 0;
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dev_dbg(dev->dev,
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"%#x STAUTS SLAVE_ACTTVITY=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
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enabled, slave_activity, raw_stat, stat);
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if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET))
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i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
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if (stat & DW_IC_INTR_RD_REQ) {
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if (slave_activity) {
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if (stat & DW_IC_INTR_RX_FULL) {
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val = dw_readl(dev, DW_IC_DATA_CMD);
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if (!i2c_slave_event(dev->slave,
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I2C_SLAVE_WRITE_RECEIVED,
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&val)) {
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dev_vdbg(dev->dev, "Byte %X acked!",
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val);
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}
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dw_readl(dev, DW_IC_CLR_RD_REQ);
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stat = i2c_dw_read_clear_intrbits_slave(dev);
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} else {
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dw_readl(dev, DW_IC_CLR_RD_REQ);
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dw_readl(dev, DW_IC_CLR_RX_UNDER);
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stat = i2c_dw_read_clear_intrbits_slave(dev);
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}
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if (!i2c_slave_event(dev->slave,
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I2C_SLAVE_READ_REQUESTED,
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&val))
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dw_writel(dev, val, DW_IC_DATA_CMD);
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}
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}
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if (stat & DW_IC_INTR_RX_DONE) {
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if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED,
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&val))
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dw_readl(dev, DW_IC_CLR_RX_DONE);
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i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
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stat = i2c_dw_read_clear_intrbits_slave(dev);
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return 1;
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}
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if (stat & DW_IC_INTR_RX_FULL) {
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val = dw_readl(dev, DW_IC_DATA_CMD);
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if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED,
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&val))
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dev_vdbg(dev->dev, "Byte %X acked!", val);
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} else {
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i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
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stat = i2c_dw_read_clear_intrbits_slave(dev);
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}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id)
|
||||
{
|
||||
struct dw_i2c_dev *dev = dev_id;
|
||||
int ret;
|
||||
|
||||
i2c_dw_read_clear_intrbits_slave(dev);
|
||||
ret = i2c_dw_irq_handler_slave(dev);
|
||||
if (ret > 0)
|
||||
complete(&dev->cmd_complete);
|
||||
|
||||
return IRQ_RETVAL(ret);
|
||||
}
|
||||
|
||||
static struct i2c_algorithm i2c_dw_algo = {
|
||||
.functionality = i2c_dw_func,
|
||||
.reg_slave = i2c_dw_reg_slave,
|
||||
.unreg_slave = i2c_dw_unreg_slave,
|
||||
};
|
||||
|
||||
int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
|
||||
{
|
||||
struct i2c_adapter *adap = &dev->adapter;
|
||||
int ret;
|
||||
|
||||
init_completion(&dev->cmd_complete);
|
||||
|
||||
dev->init = i2c_dw_init_slave;
|
||||
dev->disable = i2c_dw_disable;
|
||||
dev->disable_int = i2c_dw_disable_int;
|
||||
|
||||
ret = dev->init(dev);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
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);
|
||||
|
||||
ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr_slave,
|
||||
IRQF_SHARED, dev_name(dev->dev), dev);
|
||||
if (ret) {
|
||||
dev_err(dev->dev, "failure requesting irq %i: %d\n",
|
||||
dev->irq, ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
ret = i2c_add_numbered_adapter(adap);
|
||||
if (ret)
|
||||
dev_err(dev->dev, "failure adding adapter: %d\n", ret);
|
||||
pm_runtime_put_noidle(dev->dev);
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(i2c_dw_probe_slave);
|
||||
|
||||
MODULE_AUTHOR("Luis Oliveira <lolivei@synopsys.com>");
|
||||
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus slave adapter");
|
||||
MODULE_LICENSE("GPL v2");
|
Loading…
Reference in New Issue