--- /dev/null
+/*
+ * 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>
+
+/*
+ * 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_CLR_INTR 0x40
+#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_TX_EMPTY 0x10
+#define DW_IC_INTR_TX_ABRT 0x40
+#define DW_IC_INTR_STOP_DET 0x200
+
+#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 ARB_MASTER_DIS 11
+#define ARB_LOST 12
+
+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)",
+ [ARB_MASTER_DIS] =
+ "trying to use disabled adapter",
+ [ARB_LOST] =
+ "lost arbitration",
+};
+
+/**
+ * struct dw_i2c_dev - private i2c-designware data
+ * @dev: driver model device node
+ * @base: IO registers pointer
+ * @cmd_complete: tx completion indicator
+ * @pump_msg: continue in progress transfers
+ * @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 tasklet_struct pump_msg;
+ struct mutex lock;
+ struct clk *clk;
+ int cmd_err;
+ struct i2c_msg *msgs;
+ int msgs_num;
+ int msg_write_idx;
+ u16 tx_buf_len;
+ u8 *tx_buf;
+ int msg_read_idx;
+ u16 rx_buf_len;
+ u8 *rx_buf;
+ int msg_err;
+ unsigned int status;
+ u16 abort_source;
+ int irq;
+ struct i2c_adapter adapter;
+ unsigned int tx_fifo_depth;
+ unsigned int rx_fifo_depth;
+};
+
+/**
+ * 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.
+ */
+static void i2c_dw_init(struct dw_i2c_dev *dev)
+{
+ u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
+ u16 ic_con;
+
+ /* Disable the adapter */
+ writeb(0, dev->base + DW_IC_ENABLE);
+
+ /* set standard and fast speed deviders for high/low periods */
+ writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
+ dev->base + DW_IC_SS_SCL_HCNT);
+ writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
+ dev->base + DW_IC_SS_SCL_LCNT);
+ writew((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
+ dev->base + DW_IC_FS_SCL_HCNT);
+ writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
+ dev->base + DW_IC_FS_SCL_LCNT);
+
+ /* 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;
+ writew(ic_con, dev->base + DW_IC_CON);
+}
+
+/*
+ * Waiting for bus not busy
+ */
+static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
+{
+ int timeout = TIMEOUT;
+
+ while (readb(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;
+}
+
+/*
+ * Initiate low level master read/write transaction.
+ * This function is called from i2c_dw_xfer when starting a transfer.
+ * This function is also called from dw_i2c_pump_msg to continue a transfer
+ * that is longer than the size of the TX FIFO.
+ */
+static void
+i2c_dw_xfer_msg(struct i2c_adapter *adap)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msgs = dev->msgs;
+ int num = dev->msgs_num;
+ u16 ic_con, intr_mask;
+ int tx_limit = dev->tx_fifo_depth - readb(dev->base + DW_IC_TXFLR);
+ int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR);
+ u16 addr = msgs[dev->msg_write_idx].addr;
+ u16 buf_len = dev->tx_buf_len;
+
+ if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+ /* Disable the adapter */
+ writeb(0, dev->base + DW_IC_ENABLE);
+
+ /* set the slave (target) address */
+ writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+
+ /* if the slave address is ten bit address, enable 10BITADDR */
+ ic_con = readw(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;
+ writew(ic_con, dev->base + DW_IC_CON);
+
+ /* Enable the adapter */
+ writeb(1, dev->base + DW_IC_ENABLE);
+ }
+
+ for (; dev->msg_write_idx < 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)
+ return;
+
+ if (msgs[dev->msg_write_idx].len == 0) {
+ dev_err(dev->dev,
+ "%s: invalid message length\n", __func__);
+ dev->msg_err = -EINVAL;
+ return;
+ }
+
+ if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+ /* new i2c_msg */
+ dev->tx_buf = msgs[dev->msg_write_idx].buf;
+ buf_len = msgs[dev->msg_write_idx].len;
+ }
+
+ while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
+ if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
+ writew(0x100, dev->base + DW_IC_DATA_CMD);
+ rx_limit--;
+ } else
+ writew(*(dev->tx_buf++),
+ dev->base + DW_IC_DATA_CMD);
+ tx_limit--; buf_len--;
+ }
+ }
+
+ intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+ if (buf_len > 0) { /* more bytes to be written */
+ intr_mask |= DW_IC_INTR_TX_EMPTY;
+ dev->status |= STATUS_WRITE_IN_PROGRESS;
+ } else
+ dev->status &= ~STATUS_WRITE_IN_PROGRESS;
+ writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+
+ dev->tx_buf_len = buf_len;
+}
+
+static void
+i2c_dw_read(struct i2c_adapter *adap)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msgs = dev->msgs;
+ int num = dev->msgs_num;
+ u16 addr = msgs[dev->msg_read_idx].addr;
+ int rx_valid = readw(dev->base + DW_IC_RXFLR);
+
+ for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
+ u16 len;
+ u8 *buf;
+
+ if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
+ continue;
+
+ /* different i2c client, reprogram the i2c adapter */
+ if (msgs[dev->msg_read_idx].addr != addr)
+ return;
+
+ 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;
+ }
+
+ for (; len > 0 && rx_valid > 0; len--, rx_valid--)
+ *buf++ = readb(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;
+ }
+}
+
+/*
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg
+ */
+static 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;
+
+ ret = i2c_dw_wait_bus_not_busy(dev);
+ if (ret < 0)
+ goto done;
+
+ /* start the transfers */
+ i2c_dw_xfer_msg(adap);
+
+ /* 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)) {
+ /* read rx fifo, and disable the adapter */
+ do {
+ i2c_dw_read(adap);
+ } while (dev->status & STATUS_READ_IN_PROGRESS);
+ writeb(0, dev->base + DW_IC_ENABLE);
+ ret = num;
+ goto done;
+ }
+
+ /* We have an error */
+ if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
+ unsigned long abort_source = dev->abort_source;
+ int i;
+
+ for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
+ dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+ }
+ }
+ ret = -EIO;
+
+done:
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static u32 i2c_dw_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
+}
+
+static void dw_i2c_pump_msg(unsigned long data)
+{
+ struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
+ u16 intr_mask;
+
+ i2c_dw_read(&dev->adapter);
+ i2c_dw_xfer_msg(&dev->adapter);
+
+ intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+ if (dev->status & STATUS_WRITE_IN_PROGRESS)
+ intr_mask |= DW_IC_INTR_TX_EMPTY;
+ writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+/*
+ * Interrupt service routine. This gets called whenever an I2C interrupt
+ * occurs.
+ */
+static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
+{
+ struct dw_i2c_dev *dev = dev_id;
+ u16 stat;
+
+ stat = readw(dev->base + DW_IC_INTR_STAT);
+ dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+ if (stat & DW_IC_INTR_TX_ABRT) {
+ dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
+ dev->cmd_err |= DW_IC_ERR_TX_ABRT;
+ dev->status = STATUS_IDLE;
+ } else if (stat & DW_IC_INTR_TX_EMPTY)
+ tasklet_schedule(&dev->pump_msg);
+
+ readb(dev->base + DW_IC_CLR_INTR); /* clear interrupts */
+ writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
+ if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
+ complete(&dev->cmd_complete);
+
+ return IRQ_HANDLED;
+}
+
+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, *irq, *ioarea;
+ int 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_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!irq) {
+ dev_err(&pdev->dev, "no irq resource?\n");
+ return -EINVAL;
+ }
+
+ 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);
+ tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
+ mutex_init(&dev->lock);
+ dev->dev = get_device(&pdev->dev);
+ dev->irq = irq->start;
+ 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);
+
+ writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+ r = request_irq(dev->irq, i2c_dw_isr, 0, 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;
+
+ writeb(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 <baruch@tkos.co.il>");
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
+MODULE_LICENSE("GPL");
projects / linux-2.6-microblaze.git / commitdiff