From: Dirk Brandewie <[email protected]>

This patch splits i2c-designware.c into a core library and associated
header file and two bus specific parts for platform bus and PCI bus.

Signed-off-by: Dirk Brandewie <[email protected]>
---
 drivers/i2c/busses/Makefile              |    4 +
 drivers/i2c/busses/i2c-designware-core.c |  541 ++++++++++++++++++++++++++++++
 drivers/i2c/busses/i2c-designware-core.h |  204 +++++++++++
 drivers/i2c/busses/i2c-designware-pci.c  |  183 ++++++++++
 drivers/i2c/busses/i2c-designware-plat.c |  198 +++++++++++
 5 files changed, 1130 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-designware-core.c
 create mode 100644 drivers/i2c/busses/i2c-designware-core.h
 create mode 100644 drivers/i2c/busses/i2c-designware-pci.c
 create mode 100644 drivers/i2c/busses/i2c-designware-plat.c

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 0b9aa00..e1c0774 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -34,6 +34,10 @@ obj-$(CONFIG_I2C_BLACKFIN_TWI)       += i2c-bfin-twi.o
 obj-$(CONFIG_I2C_CPM)          += i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)      += i2c-davinci.o
 obj-$(CONFIG_I2C_DESIGNWARE)   += i2c-designware.o
+obj-$(CONFIG_I2C_DESIGNWARE_PCI)       += i2c_dw_pci.o
+i2c_dw_pci-objs := i2c-designware-pci.o i2c-designware-core.o
+obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)  += i2c_dw_plat.o
+i2c_dw_plat-objs := i2c-designware-plat.o i2c-designware-core.o
 obj-$(CONFIG_I2C_GPIO)         += i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)   += i2c-highlander.o
 obj-$(CONFIG_I2C_IBM_IIC)      += i2c-ibm_iic.o
diff --git a/drivers/i2c/busses/i2c-designware-core.c 
b/drivers/i2c/busses/i2c-designware-core.c
new file mode 100644
index 0000000..9dca409
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -0,0 +1,541 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include "i2c-designware-core.h"
+
+static char *abort_sources[] = {
+       [ABRT_7B_ADDR_NOACK] =
+               "slave address not acknowledged (7bit mode)",
+       [ABRT_10ADDR1_NOACK] =
+               "first address byte not acknowledged (10bit mode)",
+       [ABRT_10ADDR2_NOACK] =
+               "second address byte not acknowledged (10bit mode)",
+       [ABRT_TXDATA_NOACK] =
+               "data not acknowledged",
+       [ABRT_GCALL_NOACK] =
+               "no acknowledgement for a general call",
+       [ABRT_GCALL_READ] =
+               "read after general call",
+       [ABRT_SBYTE_ACKDET] =
+               "start byte acknowledged",
+       [ABRT_SBYTE_NORSTRT] =
+               "trying to send start byte when restart is disabled",
+       [ABRT_10B_RD_NORSTRT] =
+               "trying to read when restart is disabled (10bit mode)",
+       [ABRT_MASTER_DIS] =
+               "trying to use disabled adapter",
+       [ARB_LOST] =
+               "lost arbitration",
+};
+
+u32
+i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
+{
+       /*
+        * DesignWare I2C core doesn't seem to have solid strategy to meet
+        * the tHD;STA timing spec.  Configuring _HCNT based on tHIGH spec
+        * will result in violation of the tHD;STA spec.
+        */
+       if (cond)
+               /*
+                * Conditional expression:
+                *
+                *   IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
+                *
+                * This is based on the DW manuals, and represents an ideal
+                * configuration.  The resulting I2C bus speed will be
+                * faster than any of the others.
+                *
+                * If your hardware is free from tHD;STA issue, try this one.
+                */
+               return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
+       else
+               /*
+                * Conditional expression:
+                *
+                *   IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
+                *
+                * This is just experimental rule; the tHD;STA period turned
+                * out to be proportinal to (_HCNT + 3).  With this setting,
+                * we could meet both tHIGH and tHD;STA timing specs.
+                *
+                * If unsure, you'd better to take this alternative.
+                *
+                * The reason why we need to take into account "tf" here,
+                * is the same as described in i2c_dw_scl_lcnt().
+                */
+               return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
+}
+
+u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
+{
+       /*
+        * Conditional expression:
+        *
+        *   IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
+        *
+        * DW I2C core starts counting the SCL CNTs for the LOW period
+        * of the SCL clock (tLOW) as soon as it pulls the SCL line.
+        * In order to meet the tLOW timing spec, we need to take into
+        * account the fall time of SCL signal (tf).  Default tf value
+        * should be 0.3 us, for safety.
+        */
+       return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
+}
+
+/**
+ * i2c_dw_init() - initialize the designware i2c master hardware
+ * @dev: device private data
+ *
+ * This functions configures and enables the I2C master.
+ * This function is called during I2C init function, and in case of timeout at
+ * run time.
+ */
+void
+i2c_dw_init(struct dw_i2c_dev *dev)
+{
+       u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
+       u32 ic_con, hcnt, lcnt;
+
+       /* Disable the adapter */
+       writel(0, dev->base + DW_IC_ENABLE);
+
+       /* set standard and fast speed deviders for high/low periods */
+
+       /* Standard-mode */
+       hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+                               40,     /* tHD;STA = tHIGH = 4.0 us */
+                               3,      /* tf = 0.3 us */
+                               0,      /* 0: DW default, 1: Ideal */
+                               0);     /* No offset */
+       lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+                               47,     /* tLOW = 4.7 us */
+                               3,      /* tf = 0.3 us */
+                               0);     /* No offset */
+       writel(hcnt, dev->base + DW_IC_SS_SCL_HCNT);
+       writel(lcnt, dev->base + DW_IC_SS_SCL_LCNT);
+       dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+
+       /* Fast-mode */
+       hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+                               6,      /* tHD;STA = tHIGH = 0.6 us */
+                               3,      /* tf = 0.3 us */
+                               0,      /* 0: DW default, 1: Ideal */
+                               0);     /* No offset */
+       lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+                               13,     /* tLOW = 1.3 us */
+                               3,      /* tf = 0.3 us */
+                               0);     /* No offset */
+       writel(hcnt, dev->base + DW_IC_FS_SCL_HCNT);
+       writel(lcnt, dev->base + DW_IC_FS_SCL_LCNT);
+       dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+
+       /* Configure Tx/Rx FIFO threshold levels */
+       writel(dev->tx_fifo_depth - 1, dev->base + DW_IC_TX_TL);
+       writel(0, dev->base + DW_IC_RX_TL);
+
+       /* configure the i2c master */
+       ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
+               DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
+       writel(ic_con, dev->base + DW_IC_CON);
+}
+EXPORT_SYMBOL(i2c_dw_init);
+
+/*
+ * Waiting for bus not busy
+ */
+int
+i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
+{
+       int timeout = TIMEOUT;
+
+       while (readl(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
+               if (timeout <= 0) {
+                       dev_warn(dev->dev, "timeout waiting for bus ready\n");
+                       return -ETIMEDOUT;
+               }
+               timeout--;
+               mdelay(1);
+       }
+
+       return 0;
+}
+
+void
+i2c_dw_xfer_init(struct dw_i2c_dev *dev)
+{
+       struct i2c_msg *msgs = dev->msgs;
+       u32 ic_con;
+
+       /* Disable the adapter */
+       writel(0, dev->base + DW_IC_ENABLE);
+
+       /* set the slave (target) address */
+       writel(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+
+       /* if the slave address is ten bit address, enable 10BITADDR */
+       ic_con = readl(dev->base + DW_IC_CON);
+       if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+               ic_con |= DW_IC_CON_10BITADDR_MASTER;
+       else
+               ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
+       writel(ic_con, dev->base + DW_IC_CON);
+
+       /* Enable the adapter */
+       writel(1, dev->base + DW_IC_ENABLE);
+
+       /* Enable interrupts */
+       writel(DW_IC_INTR_DEFAULT_MASK, dev->base + DW_IC_INTR_MASK);
+}
+
+/*
+ * Initiate (and continue) low level master read/write transaction.
+ * This function is only called from i2c_dw_isr, and pumping i2c_msg
+ * messages into the tx buffer.  Even if the size of i2c_msg data is
+ * longer than the size of the tx buffer, it handles everything.
+ */
+void
+i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
+{
+       struct i2c_msg *msgs = dev->msgs;
+       u32 intr_mask;
+       int tx_limit, rx_limit;
+       u32 addr = msgs[dev->msg_write_idx].addr;
+       u32 buf_len = dev->tx_buf_len;
+       u8 *buf = dev->tx_buf;;
+
+       intr_mask = DW_IC_INTR_DEFAULT_MASK;
+
+       for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
+               /*
+                * if target address has changed, we need to
+                * reprogram the target address in the i2c
+                * adapter when we are done with this transfer
+                */
+               if (msgs[dev->msg_write_idx].addr != addr) {
+                       dev_err(dev->dev,
+                               "%s: invalid target address\n", __func__);
+                       dev->msg_err = -EINVAL;
+                       break;
+               }
+
+               if (msgs[dev->msg_write_idx].len == 0) {
+                       dev_err(dev->dev,
+                               "%s: invalid message length\n", __func__);
+                       dev->msg_err = -EINVAL;
+                       break;
+               }
+
+               if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+                       /* new i2c_msg */
+                       buf = msgs[dev->msg_write_idx].buf;
+                       buf_len = msgs[dev->msg_write_idx].len;
+               }
+
+               tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR);
+               rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR);
+
+               while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
+                       if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
+                               writel(0x100, dev->base + DW_IC_DATA_CMD);
+                               rx_limit--;
+                       } else
+                               writel(*buf++, dev->base + DW_IC_DATA_CMD);
+                       tx_limit--; buf_len--;
+               }
+
+               dev->tx_buf = buf;
+               dev->tx_buf_len = buf_len;
+
+               if (buf_len > 0) {
+                       /* more bytes to be written */
+                       dev->status |= STATUS_WRITE_IN_PROGRESS;
+                       break;
+               } else
+                       dev->status &= ~STATUS_WRITE_IN_PROGRESS;
+       }
+
+       /*
+        * If i2c_msg index search is completed, we don't need TX_EMPTY
+        * interrupt any more.
+        */
+       if (dev->msg_write_idx == dev->msgs_num)
+               intr_mask &= ~DW_IC_INTR_TX_EMPTY;
+
+       if (dev->msg_err)
+               intr_mask = 0;
+
+       writel(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+void
+i2c_dw_read(struct dw_i2c_dev *dev)
+{
+       struct i2c_msg *msgs = dev->msgs;
+       int rx_valid;
+
+       for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
+               u32 len;
+               u8 *buf;
+
+               if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
+                       continue;
+
+               if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
+                       len = msgs[dev->msg_read_idx].len;
+                       buf = msgs[dev->msg_read_idx].buf;
+               } else {
+                       len = dev->rx_buf_len;
+                       buf = dev->rx_buf;
+               }
+
+               rx_valid = readl(dev->base + DW_IC_RXFLR);
+
+               for (; len > 0 && rx_valid > 0; len--, rx_valid--)
+                       *buf++ = readl(dev->base + DW_IC_DATA_CMD);
+
+               if (len > 0) {
+                       dev->status |= STATUS_READ_IN_PROGRESS;
+                       dev->rx_buf_len = len;
+                       dev->rx_buf = buf;
+                       return;
+               } else
+                       dev->status &= ~STATUS_READ_IN_PROGRESS;
+       }
+}
+
+int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
+{
+       unsigned long abort_source = dev->abort_source;
+       int i;
+
+       if (abort_source & DW_IC_TX_ABRT_NOACK) {
+               for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
+                       dev_dbg(dev->dev,
+                               "%s: %s\n", __func__, abort_sources[i]);
+               return -EREMOTEIO;
+       }
+
+       for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
+               dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+
+       if (abort_source & DW_IC_TX_ARB_LOST)
+               return -EAGAIN;
+       else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
+               return -EINVAL; /* wrong msgs[] data */
+       else
+               return -EIO;
+}
+
+/*
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg
+ */
+int
+i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+       struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+       int ret;
+
+       dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+
+       mutex_lock(&dev->lock);
+
+       INIT_COMPLETION(dev->cmd_complete);
+       dev->msgs = msgs;
+       dev->msgs_num = num;
+       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;
+
+       ret = i2c_dw_wait_bus_not_busy(dev);
+       if (ret < 0)
+               goto done;
+
+       /* start the transfers */
+       i2c_dw_xfer_init(dev);
+
+       /* wait for tx to complete */
+       ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
+       if (ret == 0) {
+               dev_err(dev->dev, "controller timed out\n");
+               i2c_dw_init(dev);
+               ret = -ETIMEDOUT;
+               goto done;
+       } else if (ret < 0)
+               goto done;
+
+       if (dev->msg_err) {
+               ret = dev->msg_err;
+               goto done;
+       }
+
+       /* no error */
+       if (likely(!dev->cmd_err)) {
+               /* Disable the adapter */
+               writel(0, dev->base + DW_IC_ENABLE);
+               ret = num;
+               goto done;
+       }
+
+       /* We have an error */
+       if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
+               ret = i2c_dw_handle_tx_abort(dev);
+               goto done;
+       }
+       ret = -EIO;
+
+done:
+       mutex_unlock(&dev->lock);
+
+       return ret;
+}
+EXPORT_SYMBOL(i2c_dw_xfer);
+
+u32 i2c_dw_func(struct i2c_adapter *adap)
+{
+       return  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;
+}
+EXPORT_SYMBOL(i2c_dw_func);
+
+u32 i2c_dw_read_clear_intrbits(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 = readl(IC_INTR_STAT);
+        * equals to,
+        *   stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
+        *
+        * The raw version might be useful for debugging purposes.
+        */
+       stat = readl(dev->base + 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
+        * readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
+        *
+        * Instead, use the separately-prepared IC_CLR_* registers.
+        */
+       if (stat & DW_IC_INTR_RX_UNDER)
+               readl(dev->base + DW_IC_CLR_RX_UNDER);
+       if (stat & DW_IC_INTR_RX_OVER)
+               readl(dev->base + DW_IC_CLR_RX_OVER);
+       if (stat & DW_IC_INTR_TX_OVER)
+               readl(dev->base + DW_IC_CLR_TX_OVER);
+       if (stat & DW_IC_INTR_RD_REQ)
+               readl(dev->base + DW_IC_CLR_RD_REQ);
+       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 = readl(dev->base + DW_IC_TX_ABRT_SOURCE);
+               readl(dev->base + DW_IC_CLR_TX_ABRT);
+       }
+       if (stat & DW_IC_INTR_RX_DONE)
+               readl(dev->base + DW_IC_CLR_RX_DONE);
+       if (stat & DW_IC_INTR_ACTIVITY)
+               readl(dev->base + DW_IC_CLR_ACTIVITY);
+       if (stat & DW_IC_INTR_STOP_DET)
+               readl(dev->base + DW_IC_CLR_STOP_DET);
+       if (stat & DW_IC_INTR_START_DET)
+               readl(dev->base + DW_IC_CLR_START_DET);
+       if (stat & DW_IC_INTR_GEN_CALL)
+               readl(dev->base + DW_IC_CLR_GEN_CALL);
+
+       return stat;
+}
+
+/*
+ * Interrupt service routine. This gets called whenever an I2C interrupt
+ * occurs.
+ */
+irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
+{
+       struct dw_i2c_dev *dev = dev_id;
+       u32 stat;
+
+       stat = i2c_dw_read_clear_intrbits(dev);
+       dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+
+       if (stat & DW_IC_INTR_TX_ABRT) {
+               dev->cmd_err |= DW_IC_ERR_TX_ABRT;
+               dev->status = STATUS_IDLE;
+
+               /*
+                * Anytime TX_ABRT is set, the contents of the tx/rx
+                * buffers are flushed.  Make sure to skip them.
+                */
+               writel(0, dev->base + DW_IC_INTR_MASK);
+               goto tx_aborted;
+       }
+
+       if (stat & DW_IC_INTR_RX_FULL)
+               i2c_dw_read(dev);
+
+       if (stat & DW_IC_INTR_TX_EMPTY)
+               i2c_dw_xfer_msg(dev);
+
+       /*
+        * No need to modify or disable the interrupt mask here.
+        * i2c_dw_xfer_msg() will take care of it according to
+        * the current transmit status.
+        */
+
+tx_aborted:
+       if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
+               complete(&dev->cmd_complete);
+
+       return IRQ_HANDLED;
+}
+EXPORT_SYMBOL(i2c_dw_isr);
diff --git a/drivers/i2c/busses/i2c-designware-core.h 
b/drivers/i2c/busses/i2c-designware-core.h
new file mode 100644
index 0000000..9558ef2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -0,0 +1,204 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+/*
+ * Registers offset
+ */
+#define DW_IC_CON              0x0
+#define DW_IC_TAR              0x4
+#define DW_IC_DATA_CMD         0x10
+#define DW_IC_SS_SCL_HCNT      0x14
+#define DW_IC_SS_SCL_LCNT      0x18
+#define DW_IC_FS_SCL_HCNT      0x1c
+#define DW_IC_FS_SCL_LCNT      0x20
+#define DW_IC_INTR_STAT                0x2c
+#define DW_IC_INTR_MASK                0x30
+#define DW_IC_RAW_INTR_STAT    0x34
+#define DW_IC_RX_TL            0x38
+#define DW_IC_TX_TL            0x3c
+#define DW_IC_CLR_INTR         0x40
+#define DW_IC_CLR_RX_UNDER     0x44
+#define DW_IC_CLR_RX_OVER      0x48
+#define DW_IC_CLR_TX_OVER      0x4c
+#define DW_IC_CLR_RD_REQ       0x50
+#define DW_IC_CLR_TX_ABRT      0x54
+#define DW_IC_CLR_RX_DONE      0x58
+#define DW_IC_CLR_ACTIVITY     0x5c
+#define DW_IC_CLR_STOP_DET     0x60
+#define DW_IC_CLR_START_DET    0x64
+#define DW_IC_CLR_GEN_CALL     0x68
+#define DW_IC_ENABLE           0x6c
+#define DW_IC_STATUS           0x70
+#define DW_IC_TXFLR            0x74
+#define DW_IC_RXFLR            0x78
+#define DW_IC_COMP_PARAM_1     0xf4
+#define DW_IC_TX_ABRT_SOURCE   0x80
+
+#define DW_IC_CON_MASTER               0x1
+#define DW_IC_CON_SPEED_STD            0x2
+#define DW_IC_CON_SPEED_FAST           0x4
+#define DW_IC_CON_10BITADDR_MASTER     0x10
+#define DW_IC_CON_RESTART_EN           0x20
+#define DW_IC_CON_SLAVE_DISABLE                0x40
+
+#define DW_IC_INTR_RX_UNDER    0x001
+#define DW_IC_INTR_RX_OVER     0x002
+#define DW_IC_INTR_RX_FULL     0x004
+#define DW_IC_INTR_TX_OVER     0x008
+#define DW_IC_INTR_TX_EMPTY    0x010
+#define DW_IC_INTR_RD_REQ      0x020
+#define DW_IC_INTR_TX_ABRT     0x040
+#define DW_IC_INTR_RX_DONE     0x080
+#define DW_IC_INTR_ACTIVITY    0x100
+#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_STATUS_ACTIVITY  0x1
+
+#define DW_IC_ERR_TX_ABRT      0x1
+
+/*
+ * status codes
+ */
+#define STATUS_IDLE                    0x0
+#define STATUS_WRITE_IN_PROGRESS       0x1
+#define STATUS_READ_IN_PROGRESS                0x2
+
+#define TIMEOUT                        20 /* ms */
+
+/*
+ * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
+ *
+ * only expected abort codes are listed here
+ * refer to the datasheet for the full list
+ */
+#define ABRT_7B_ADDR_NOACK     0
+#define ABRT_10ADDR1_NOACK     1
+#define ABRT_10ADDR2_NOACK     2
+#define ABRT_TXDATA_NOACK      3
+#define ABRT_GCALL_NOACK       4
+#define ABRT_GCALL_READ                5
+#define ABRT_SBYTE_ACKDET      7
+#define ABRT_SBYTE_NORSTRT     9
+#define ABRT_10B_RD_NORSTRT    10
+#define ABRT_MASTER_DIS                11
+#define ARB_LOST               12
+
+#define DW_IC_TX_ABRT_7B_ADDR_NOACK    (1UL << ABRT_7B_ADDR_NOACK)
+#define DW_IC_TX_ABRT_10ADDR1_NOACK    (1UL << ABRT_10ADDR1_NOACK)
+#define DW_IC_TX_ABRT_10ADDR2_NOACK    (1UL << ABRT_10ADDR2_NOACK)
+#define DW_IC_TX_ABRT_TXDATA_NOACK     (1UL << ABRT_TXDATA_NOACK)
+#define DW_IC_TX_ABRT_GCALL_NOACK      (1UL << ABRT_GCALL_NOACK)
+#define DW_IC_TX_ABRT_GCALL_READ       (1UL << ABRT_GCALL_READ)
+#define DW_IC_TX_ABRT_SBYTE_ACKDET     (1UL << ABRT_SBYTE_ACKDET)
+#define DW_IC_TX_ABRT_SBYTE_NORSTRT    (1UL << ABRT_SBYTE_NORSTRT)
+#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_TX_ABRT_NOACK            (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
+                                        DW_IC_TX_ABRT_10ADDR1_NOACK | \
+                                        DW_IC_TX_ABRT_10ADDR2_NOACK | \
+                                        DW_IC_TX_ABRT_TXDATA_NOACK | \
+                                        DW_IC_TX_ABRT_GCALL_NOACK)
+
+
+/**
+ * struct dw_i2c_dev - private i2c-designware data
+ * @dev: driver model device node
+ * @base: IO registers pointer
+ * @cmd_complete: tx completion indicator
+ * @lock: protect this struct and IO registers
+ * @clk: input reference clock
+ * @cmd_err: run time hadware error code
+ * @msgs: points to an array of messages currently being transfered
+ * @msgs_num: the number of elements in msgs
+ * @msg_write_idx: the element index of the current tx message in the msgs
+ *     array
+ * @tx_buf_len: the length of the current tx buffer
+ * @tx_buf: the current tx buffer
+ * @msg_read_idx: the element index of the current rx message in the msgs
+ *     array
+ * @rx_buf_len: the length of the current rx buffer
+ * @rx_buf: the current rx buffer
+ * @msg_err: error status of the current transfer
+ * @status: i2c master status, one of STATUS_*
+ * @abort_source: copy of the TX_ABRT_SOURCE register
+ * @irq: interrupt number for the i2c master
+ * @adapter: i2c subsystem adapter node
+ * @tx_fifo_depth: depth of the hardware tx fifo
+ * @rx_fifo_depth: depth of the hardware rx fifo
+ */
+struct dw_i2c_dev {
+       struct device           *dev;
+       void __iomem            *base;
+       struct completion       cmd_complete;
+       struct mutex            lock;
+       struct clk              *clk;
+       int                     cmd_err;
+       struct i2c_msg          *msgs;
+       int                     msgs_num;
+       int                     msg_write_idx;
+       u32                     tx_buf_len;
+       u8                      *tx_buf;
+       int                     msg_read_idx;
+       u32                     rx_buf_len;
+       u8                      *rx_buf;
+       int                     msg_err;
+       unsigned int            status;
+       u32                     abort_source;
+       int                     irq;
+       struct i2c_adapter      adapter;
+       unsigned int            tx_fifo_depth;
+       unsigned int            rx_fifo_depth;
+};
+
+
+extern void i2c_dw_init(struct dw_i2c_dev *dev);
+extern int i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
+               int num);
+extern u32 i2c_dw_func(struct i2c_adapter *adap);
+extern irqreturn_t i2c_dw_isr(int this_irq, void *dev_id);
diff --git a/drivers/i2c/busses/i2c-designware-pci.c 
b/drivers/i2c/busses/i2c-designware-pci.c
new file mode 100644
index 0000000..11185b2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-pci.c
@@ -0,0 +1,183 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * ----------------------------------------------------------------------------
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include "i2c-designware-core.h"
+
+static struct i2c_algorithm i2c_dw_algo = {
+       .master_xfer    = i2c_dw_xfer,
+       .functionality  = i2c_dw_func,
+};
+
+static int __devinit dw_i2c_probe(struct platform_device *pdev)
+{
+       struct dw_i2c_dev *dev;
+       struct i2c_adapter *adap;
+       struct resource *mem, *ioarea;
+       int irq, r;
+
+       /* NOTE: driver uses the static register mapping */
+       mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!mem) {
+               dev_err(&pdev->dev, "no mem resource?\n");
+               return -EINVAL;
+       }
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "no irq resource?\n");
+               return irq; /* -ENXIO */
+       }
+
+       ioarea = request_mem_region(mem->start, resource_size(mem),
+                       pdev->name);
+       if (!ioarea) {
+               dev_err(&pdev->dev, "I2C region already claimed\n");
+               return -EBUSY;
+       }
+
+       dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
+       if (!dev) {
+               r = -ENOMEM;
+               goto err_release_region;
+       }
+
+       init_completion(&dev->cmd_complete);
+       mutex_init(&dev->lock);
+       dev->dev = get_device(&pdev->dev);
+       dev->irq = irq;
+       platform_set_drvdata(pdev, dev);
+
+
+       dev->base = ioremap(mem->start, resource_size(mem));
+       if (dev->base == NULL) {
+               dev_err(&pdev->dev, "failure mapping io resources\n");
+               r = -EBUSY;
+               goto err_unuse_clocks;
+       }
+       {
+               u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1);
+
+               dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
+               dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
+       }
+       i2c_dw_init(dev);
+
+       writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+       r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
+       if (r) {
+               dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
+               goto err_iounmap;
+       }
+
+       adap = &dev->adapter;
+       i2c_set_adapdata(adap, dev);
+       adap->owner = THIS_MODULE;
+       adap->class = I2C_CLASS_HWMON;
+       strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
+                       sizeof(adap->name));
+       adap->algo = &i2c_dw_algo;
+       adap->dev.parent = &pdev->dev;
+
+       adap->nr = pdev->id;
+       r = i2c_add_numbered_adapter(adap);
+       if (r) {
+               dev_err(&pdev->dev, "failure adding adapter\n");
+               goto err_free_irq;
+       }
+
+       return 0;
+
+err_free_irq:
+       free_irq(dev->irq, dev);
+err_iounmap:
+       iounmap(dev->base);
+err_free_mem:
+       platform_set_drvdata(pdev, NULL);
+       put_device(&pdev->dev);
+       kfree(dev);
+err_release_region:
+       release_mem_region(mem->start, resource_size(mem));
+
+       return r;
+}
+
+static int __devexit dw_i2c_remove(struct platform_device *pdev)
+{
+       struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+       struct resource *mem;
+
+       platform_set_drvdata(pdev, NULL);
+       i2c_del_adapter(&dev->adapter);
+       put_device(&pdev->dev);
+
+       writel(0, dev->base + DW_IC_ENABLE);
+       free_irq(dev->irq, dev);
+       kfree(dev);
+
+       mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       release_mem_region(mem->start, resource_size(mem));
+       return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_designware");
+
+static struct platform_driver dw_i2c_driver = {
+       .remove         = __devexit_p(dw_i2c_remove),
+       .driver         = {
+               .name   = "i2c_designware",
+               .owner  = THIS_MODULE,
+       },
+};
+
+static int __init dw_i2c_init_driver(void)
+{
+       return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
+}
+module_init(dw_i2c_init_driver);
+
+static void __exit dw_i2c_exit_driver(void)
+{
+       platform_driver_unregister(&dw_i2c_driver);
+}
+module_exit(dw_i2c_exit_driver);
+
+MODULE_AUTHOR("Baruch Siach <[email protected]>");
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
+MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-designware-plat.c 
b/drivers/i2c/busses/i2c-designware-plat.c
new file mode 100644
index 0000000..b8e5aa4
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-plat.c
@@ -0,0 +1,198 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include "i2c-designware-core.h"
+
+static struct i2c_algorithm i2c_dw_algo = {
+       .master_xfer    = i2c_dw_xfer,
+       .functionality  = i2c_dw_func,
+};
+
+static int __devinit dw_i2c_probe(struct platform_device *pdev)
+{
+       struct dw_i2c_dev *dev;
+       struct i2c_adapter *adap;
+       struct resource *mem, *ioarea;
+       int irq, r;
+
+       /* NOTE: driver uses the static register mapping */
+       mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!mem) {
+               dev_err(&pdev->dev, "no mem resource?\n");
+               return -EINVAL;
+       }
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "no irq resource?\n");
+               return irq; /* -ENXIO */
+       }
+
+       ioarea = request_mem_region(mem->start, resource_size(mem),
+                       pdev->name);
+       if (!ioarea) {
+               dev_err(&pdev->dev, "I2C region already claimed\n");
+               return -EBUSY;
+       }
+
+       dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
+       if (!dev) {
+               r = -ENOMEM;
+               goto err_release_region;
+       }
+
+       init_completion(&dev->cmd_complete);
+       mutex_init(&dev->lock);
+       dev->dev = get_device(&pdev->dev);
+       dev->irq = irq;
+       platform_set_drvdata(pdev, dev);
+
+       dev->clk = clk_get(&pdev->dev, NULL);
+       if (IS_ERR(dev->clk)) {
+               r = -ENODEV;
+               goto err_free_mem;
+       }
+       clk_enable(dev->clk);
+
+       dev->base = ioremap(mem->start, resource_size(mem));
+       if (dev->base == NULL) {
+               dev_err(&pdev->dev, "failure mapping io resources\n");
+               r = -EBUSY;
+               goto err_unuse_clocks;
+       }
+       {
+               u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1);
+
+               dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
+               dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
+       }
+       i2c_dw_init(dev);
+
+       writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+       r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
+       if (r) {
+               dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
+               goto err_iounmap;
+       }
+
+       adap = &dev->adapter;
+       i2c_set_adapdata(adap, dev);
+       adap->owner = THIS_MODULE;
+       adap->class = I2C_CLASS_HWMON;
+       strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
+                       sizeof(adap->name));
+       adap->algo = &i2c_dw_algo;
+       adap->dev.parent = &pdev->dev;
+
+       adap->nr = pdev->id;
+       r = i2c_add_numbered_adapter(adap);
+       if (r) {
+               dev_err(&pdev->dev, "failure adding adapter\n");
+               goto err_free_irq;
+       }
+
+       return 0;
+
+err_free_irq:
+       free_irq(dev->irq, dev);
+err_iounmap:
+       iounmap(dev->base);
+err_unuse_clocks:
+       clk_disable(dev->clk);
+       clk_put(dev->clk);
+       dev->clk = NULL;
+err_free_mem:
+       platform_set_drvdata(pdev, NULL);
+       put_device(&pdev->dev);
+       kfree(dev);
+err_release_region:
+       release_mem_region(mem->start, resource_size(mem));
+
+       return r;
+}
+
+static int __devexit dw_i2c_remove(struct platform_device *pdev)
+{
+       struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+       struct resource *mem;
+
+       platform_set_drvdata(pdev, NULL);
+       i2c_del_adapter(&dev->adapter);
+       put_device(&pdev->dev);
+
+       clk_disable(dev->clk);
+       clk_put(dev->clk);
+       dev->clk = NULL;
+
+       writel(0, dev->base + DW_IC_ENABLE);
+       free_irq(dev->irq, dev);
+       kfree(dev);
+
+       mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       release_mem_region(mem->start, resource_size(mem));
+       return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_designware");
+
+static struct platform_driver dw_i2c_driver = {
+       .remove         = __devexit_p(dw_i2c_remove),
+       .driver         = {
+               .name   = "i2c_designware",
+               .owner  = THIS_MODULE,
+       },
+};
+
+static int __init dw_i2c_init_driver(void)
+{
+       return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
+}
+module_init(dw_i2c_init_driver);
+
+static void __exit dw_i2c_exit_driver(void)
+{
+       platform_driver_unregister(&dw_i2c_driver);
+}
+module_exit(dw_i2c_exit_driver);
+
+MODULE_AUTHOR("Baruch Siach <[email protected]>");
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
+MODULE_LICENSE("GPL");
-- 
1.7.3.4

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