1 files changed, 14 insertions, 172 deletions

diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 1f58197062cf..286ca1917820 100644
--- a/drivers/i2c/busses/i2c-mxs.c
+++ b/drivers/i2c/busses/i2c-mxs.c
@@ -1,7 +1,7 @@
 /*
  * Freescale MXS I2C bus driver
  *
- * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
+ * Copyright (C) 2011-2012 Wolfram Sang, Pengutronix e.K.
  *
  * based on a (non-working) driver which was:
  *
@@ -35,10 +35,6 @@
 
 #define DRIVER_NAME "mxs-i2c"
 
-static bool use_pioqueue;
-module_param(use_pioqueue, bool, 0);
-MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA");
-
 #define MXS_I2C_CTRL0           (0x00)
 #define MXS_I2C_CTRL0_SET       (0x04)
 
@@ -75,23 +71,6 @@ MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA");
                                  MXS_I2C_CTRL1_SLAVE_STOP_IRQ | \
                                  MXS_I2C_CTRL1_SLAVE_IRQ)
 
-#define MXS_I2C_QUEUECTRL       (0x60)
-#define MXS_I2C_QUEUECTRL_SET   (0x64)
-#define MXS_I2C_QUEUECTRL_CLR   (0x68)
-
-#define MXS_I2C_QUEUECTRL_QUEUE_RUN             0x20
-#define MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE        0x04
-
-#define MXS_I2C_QUEUESTAT       (0x70)
-#define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY        0x00002000
-#define MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK  0x0000001F
-
-#define MXS_I2C_QUEUECMD        (0x80)
-
-#define MXS_I2C_QUEUEDATA       (0x90)
-
-#define MXS_I2C_DATA            (0xa0)
-
 
 #define MXS_CMD_I2C_SELECT      (MXS_I2C_CTRL0_RETAIN_CLOCK |   \
                                  MXS_I2C_CTRL0_PRE_SEND_START | \
@@ -153,7 +132,6 @@ struct mxs_i2c_dev {
         const struct mxs_i2c_speed_config *speed;
 
         /* DMA support components */
-        bool                            dma_mode;
         int                             dma_channel;
         struct dma_chan                 *dmach;
         struct mxs_dma_data             dma_data;
@@ -172,99 +150,6 @@ static void mxs_i2c_reset(struct mxs_i2c_dev *i2c)
         writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2);
 
         writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET);
-        if (i2c->dma_mode)
-                writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
-                        i2c->regs + MXS_I2C_QUEUECTRL_CLR);
-        else
-                writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
-                        i2c->regs + MXS_I2C_QUEUECTRL_SET);
-}
-
-static void mxs_i2c_pioq_setup_read(struct mxs_i2c_dev *i2c, u8 addr, int len,
-                                        int flags)
-{
-        u32 data;
-
-        writel(MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_QUEUECMD);
-
-        data = (addr << 1) | I2C_SMBUS_READ;
-        writel(data, i2c->regs + MXS_I2C_DATA);
-
-        data = MXS_CMD_I2C_READ | MXS_I2C_CTRL0_XFER_COUNT(len) | flags;
-        writel(data, i2c->regs + MXS_I2C_QUEUECMD);
-}
-
-static void mxs_i2c_pioq_setup_write(struct mxs_i2c_dev *i2c,
-                                    u8 addr, u8 *buf, int len, int flags)
-{
-        u32 data;
-        int i, shifts_left;
-
-        data = MXS_CMD_I2C_WRITE | MXS_I2C_CTRL0_XFER_COUNT(len + 1) | flags;
-        writel(data, i2c->regs + MXS_I2C_QUEUECMD);
-
-        /*
-         * We have to copy the slave address (u8) and buffer (arbitrary number
-         * of u8) into the data register (u32). To achieve that, the u8 are put
-         * into the MSBs of 'data' which is then shifted for the next u8. When
-         * appropriate, 'data' is written to MXS_I2C_DATA. So, the first u32
-         * looks like this:
-         *
-         *  3          2          1          0
-         * 10987654|32109876|54321098|76543210
-         * --------+--------+--------+--------
-         * buffer+2|buffer+1|buffer+0|slave_addr
-         */
-
-        data = ((addr << 1) | I2C_SMBUS_WRITE) << 24;
-
-        for (i = 0; i < len; i++) {
-                data >>= 8;
-                data |= buf[i] << 24;
-                if ((i & 3) == 2)
-                        writel(data, i2c->regs + MXS_I2C_DATA);
-        }
-
-        /* Write out the remaining bytes if any */
-        shifts_left = 24 - (i & 3) * 8;
-        if (shifts_left)
-                writel(data >> shifts_left, i2c->regs + MXS_I2C_DATA);
-}
-
-/*
- * TODO: should be replaceable with a waitqueue and RD_QUEUE_IRQ (setting the
- * rd_threshold to 1). Couldn't get this to work, though.
- */
-static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c)
-{
-        unsigned long timeout = jiffies + msecs_to_jiffies(1000);
-
-        while (readl(i2c->regs + MXS_I2C_QUEUESTAT)
-                        & MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY) {
-                        if (time_after(jiffies, timeout))
-                                return -ETIMEDOUT;
-                        cond_resched();
-        }
-
-        return 0;
-}
-
-static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len)
-{
-        u32 uninitialized_var(data);
-        int i;
-
-        for (i = 0; i < len; i++) {
-                if ((i & 3) == 0) {
-                        if (mxs_i2c_wait_for_data(i2c))
-                                return -ETIMEDOUT;
-                        data = readl(i2c->regs + MXS_I2C_QUEUEDATA);
-                }
-                buf[i] = data & 0xff;
-                data >>= 8;
-        }
-
-        return 0;
 }
 
 static void mxs_i2c_dma_finish(struct mxs_i2c_dev *i2c)
@@ -432,39 +317,17 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
         init_completion(&i2c->cmd_complete);
         i2c->cmd_err = 0;
 
-        if (i2c->dma_mode) {
-                ret = mxs_i2c_dma_setup_xfer(adap, msg, flags);
-                if (ret)
-                        return ret;
-        } else {
-                if (msg->flags & I2C_M_RD) {
-                        mxs_i2c_pioq_setup_read(i2c, msg->addr,
-                                                msg->len, flags);
-                } else {
-                        mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf,
-                                                msg->len, flags);
-                }
-
-                writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
-                        i2c->regs + MXS_I2C_QUEUECTRL_SET);
-        }
+        ret = mxs_i2c_dma_setup_xfer(adap, msg, flags);
+        if (ret)
+                return ret;
 
         ret = wait_for_completion_timeout(&i2c->cmd_complete,
                                                 msecs_to_jiffies(1000));
         if (ret == 0)
                 goto timeout;
 
-        if (!i2c->dma_mode && !i2c->cmd_err && (msg->flags & I2C_M_RD)) {
-                ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len);
-                if (ret)
-                        goto timeout;
-        }
-
         if (i2c->cmd_err == -ENXIO)
                 mxs_i2c_reset(i2c);
-        else
-                writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
-                                i2c->regs + MXS_I2C_QUEUECTRL_CLR);
 
         dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err);
 
@@ -472,8 +335,7 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
 
 timeout:
         dev_dbg(i2c->dev, "Timeout!\n");
-        if (i2c->dma_mode)
-                mxs_i2c_dma_finish(i2c);
+        mxs_i2c_dma_finish(i2c);
         mxs_i2c_reset(i2c);
         return -ETIMEDOUT;
 }
@@ -502,7 +364,6 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id)
 {
         struct mxs_i2c_dev *i2c = dev_id;
         u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK;
-        bool is_last_cmd;
 
         if (!stat)
                 return IRQ_NONE;
@@ -515,14 +376,6 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id)
                 /* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */
                 i2c->cmd_err = -EIO;
 
-        if (!i2c->dma_mode) {
-                is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) &
-                        MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0;
-
-                if (is_last_cmd || i2c->cmd_err)
-                        complete(&i2c->cmd_complete);
-        }
-
         writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR);
 
         return IRQ_HANDLED;
@@ -556,23 +409,14 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c)
         int ret;
 
         /*
-         * The MXS I2C DMA mode is prefered and enabled by default.
-         * The PIO mode is still supported, but should be used only
-         * for debuging purposes etc.
-         */
-        i2c->dma_mode = !use_pioqueue;
-        if (!i2c->dma_mode)
-                dev_info(dev, "Using PIOQUEUE mode for I2C transfers!\n");
-
-        /*
          * TODO: This is a temporary solution and should be changed
          * to use generic DMA binding later when the helpers get in.
          */
         ret = of_property_read_u32(node, "fsl,i2c-dma-channel",
                                    &i2c->dma_channel);
         if (ret) {
-                dev_warn(dev, "Failed to get DMA channel, using PIOQUEUE!\n");
-                i2c->dma_mode = 0;
+                dev_err(dev, "Failed to get DMA channel!\n");
+                return -ENODEV;
         }
 
         ret = of_property_read_u32(node, "clock-frequency", &speed);
@@ -634,15 +478,13 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev)
         }
 
         /* Setup the DMA */
-        if (i2c->dma_mode) {
-                dma_cap_zero(mask);
-                dma_cap_set(DMA_SLAVE, mask);
-                i2c->dma_data.chan_irq = dmairq;
-                i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c);
-                if (!i2c->dmach) {
-                        dev_err(dev, "Failed to request dma\n");
-                        return -ENODEV;
-                }
+        dma_cap_zero(mask);
+        dma_cap_set(DMA_SLAVE, mask);
+        i2c->dma_data.chan_irq = dmairq;
+        i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c);
+        if (!i2c->dmach) {
+                dev_err(dev, "Failed to request dma\n");
+                return -ENODEV;
         }
 
         platform_set_drvdata(pdev, i2c);