On Wed, 2016-12-28 at 14:43 +0000, Luis Oliveira wrote:
> - Changes in Kconfig to enable I2C_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 it all
>
> All the SLAVE flow is added but it is not enabled via platform
> driver.
> --- a/drivers/i2c/busses/i2c-designware-common.c
> +++ b/drivers/i2c/busses/i2c-designware-common.c
> @@ -30,6 +30,7 @@
> #include <linux/pm_runtime.h>
> #include <linux/delay.h>
> #include <linux/module.h>
> +
> #include "i2c-designware-core.h"
>
> static char *abort_sources[] = {
> @@ -42,7 +43,7 @@ static char *abort_sources[] = {
> [ABRT_TXDATA_NOACK] =
> "data not acknowledged",
> [ABRT_GCALL_NOACK] =
> - "no acknowledgement for a general call",
> + "no acknowledgment for a general call",
So, what's the point after your confirmation that both variants are
okay?
> +#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>
Alphabetical order?
> +int i2c_dw_init_slave(struct dw_i2c_dev *dev)
> +{
> + u32 sda_falling_time, scl_falling_time;
> + u32 reg, comp_param1;
> + u32 hcnt, lcnt;
> + 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);
Is it correct indentation?
> + 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);
> + 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);
Can we introduce ops structure for those? (private callbacks)
You increase noise in namespace by several i2c_dw_*() functions.
Introduction of ops will keep everything private.
> +
> +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.
> + */
Wrong indentation?
> +
> + __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;
Extra spaces, remove.
> +
> + return 0;
> +}
>
> +static int 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);
> +
> + if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY))
> + return 0;
> +
> + dev_dbg(dev->dev,
> + "%s: %#x SLAVE_ACTV=%#x : RAW_INTR_STAT=%#x :
> INTR_STAT=%#x\n",
> + __func__, enabled, slave_activity, raw_stat, stat);
__func__ is redundant.
> +
> + if (stat & DW_IC_INTR_RESTART_DET)
> + dw_readl(dev, DW_IC_CLR_RESTART_DET);
> + 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);
Perhaps dev_vdbg() ?
> + }
> + 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;
Mistype of value. Should be 1?
> + }
> +
> + 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_vdbg() ?
> + } 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 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);
> +
Swap these lines.
> + if (ret > 0)
> + complete(&dev->cmd_complete);
> +
> + return IRQ_RETVAL(ret);
> +}
> +
> +int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
> +{
> + struct i2c_adapter *adap = &dev->adapter;
> + int ret;
> +
> + init_completion(&dev->cmd_complete);
> +
> + ret = i2c_dw_init_slave(dev);
> + if (ret)
> + return ret;
> +
>
> + ret = i2c_dw_acquire_lock(dev);
> + if (ret)
> + return ret;
I'm not sure you need this in slave code.
> +
> + 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);
> +
> + 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;
> + }
> + /*
> + * 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);
Looks like you blindly copied this from master code. This is about slave
enumeration. How does it related to slave mode?
> + 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);
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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