1 files changed, 59 insertions, 207 deletions

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index d4fa8eba6e9d..899405923678 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -1,7 +1,9 @@
 /*
- *  drivers/i2c/busses/i2c-rcar.c
+ * Driver for the Renesas RCar I2C unit
  *
- * Copyright (C) 2012 Renesas Solutions Corp.
+ * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
+ *
+ * Copyright (C) 2012-14 Renesas Solutions Corp.
  * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
  *
  * This file is based on the drivers/i2c/busses/i2c-sh7760.c
@@ -12,16 +14,12 @@
  *
  * 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
+ * the Free Software Foundation; version 2 of the License.
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 #include <linux/clk.h>
 #include <linux/delay.h>
@@ -36,7 +34,6 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
-#include <linux/spinlock.h>
 
 /* register offsets */
 #define ICSCR   0x00    /* slave ctrl */
@@ -60,7 +57,7 @@
 #define FSB     (1 << 1)        /* force stop bit */
 #define ESG     (1 << 0)        /* en startbit gen */
 
-/* ICMSR */
+/* ICMSR (also for ICMIE) */
 #define MNR     (1 << 6)        /* nack received */
 #define MAL     (1 << 5)        /* arbitration lost */
 #define MST     (1 << 4)        /* sent a stop */
@@ -69,32 +66,18 @@
 #define MDR     (1 << 1)
 #define MAT     (1 << 0)        /* slave addr xfer done */
 
-/* ICMIE */
-#define MNRE    (1 << 6)        /* nack irq en */
-#define MALE    (1 << 5)        /* arblos irq en */
-#define MSTE    (1 << 4)        /* stop irq en */
-#define MDEE    (1 << 3)
-#define MDTE    (1 << 2)
-#define MDRE    (1 << 1)
-#define MATE    (1 << 0)        /* address sent irq en */
 
+#define RCAR_BUS_PHASE_START    (MDBS | MIE | ESG)
+#define RCAR_BUS_PHASE_DATA     (MDBS | MIE)
+#define RCAR_BUS_PHASE_STOP     (MDBS | MIE | FSB)
 
-enum {
-        RCAR_BUS_PHASE_ADDR,
-        RCAR_BUS_PHASE_DATA,
-        RCAR_BUS_PHASE_STOP,
-};
+#define RCAR_IRQ_SEND   (MNR | MAL | MST | MAT | MDE)
+#define RCAR_IRQ_RECV   (MNR | MAL | MST | MAT | MDR)
+#define RCAR_IRQ_STOP   (MST)
 
-enum {
-        RCAR_IRQ_CLOSE,
-        RCAR_IRQ_OPEN_FOR_SEND,
-        RCAR_IRQ_OPEN_FOR_RECV,
-        RCAR_IRQ_OPEN_FOR_STOP,
-};
+#define RCAR_IRQ_ACK_SEND       (~(MAT | MDE))
+#define RCAR_IRQ_ACK_RECV       (~(MAT | MDR))
 
-/*
- * flags
- */
 #define ID_LAST_MSG     (1 << 0)
 #define ID_IOERROR      (1 << 1)
 #define ID_DONE         (1 << 2)
@@ -112,14 +95,12 @@ struct rcar_i2c_priv {
         struct i2c_msg  *msg;
         struct clk *clk;
 
-        spinlock_t lock;
         wait_queue_head_t wait;
 
         int pos;
-        int irq;
         u32 icccr;
         u32 flags;
-        enum rcar_i2c_type      devtype;
+        enum rcar_i2c_type devtype;
 };
 
 #define rcar_i2c_priv_to_dev(p)         ((p)->adap.dev.parent)
@@ -130,9 +111,7 @@ struct rcar_i2c_priv {
 
 #define LOOP_TIMEOUT    1024
 
-/*
- *              basic functions
- */
+
 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
 {
         writel(val, priv->io + reg);
@@ -161,36 +140,6 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
         rcar_i2c_write(priv, ICMAR, 0);
 }
 
-static void rcar_i2c_irq_mask(struct rcar_i2c_priv *priv, int open)
-{
-        u32 val = MNRE | MALE | MSTE | MATE; /* default */
-
-        switch (open) {
-        case RCAR_IRQ_OPEN_FOR_SEND:
-                val |= MDEE; /* default + send */
-                break;
-        case RCAR_IRQ_OPEN_FOR_RECV:
-                val |= MDRE; /* default + read */
-                break;
-        case RCAR_IRQ_OPEN_FOR_STOP:
-                val = MSTE; /* stop irq only */
-                break;
-        case RCAR_IRQ_CLOSE:
-        default:
-                val = 0; /* all close */
-                break;
-        }
-        rcar_i2c_write(priv, ICMIER, val);
-}
-
-static void rcar_i2c_set_addr(struct rcar_i2c_priv *priv, u32 recv)
-{
-        rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | recv);
-}
-
-/*
- *              bus control functions
- */
 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 {
         int i;
@@ -205,24 +154,6 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
         return -EBUSY;
 }
 
-static void rcar_i2c_bus_phase(struct rcar_i2c_priv *priv, int phase)
-{
-        switch (phase) {
-        case RCAR_BUS_PHASE_ADDR:
-                rcar_i2c_write(priv, ICMCR, MDBS | MIE | ESG);
-                break;
-        case RCAR_BUS_PHASE_DATA:
-                rcar_i2c_write(priv, ICMCR, MDBS | MIE);
-                break;
-        case RCAR_BUS_PHASE_STOP:
-                rcar_i2c_write(priv, ICMCR, MDBS | MIE | FSB);
-                break;
-        }
-}
-
-/*
- *              clock function
- */
 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
                                     u32 bus_speed,
                                     struct device *dev)
@@ -312,60 +243,18 @@ scgd_find:
         return 0;
 }
 
-static void rcar_i2c_clock_start(struct rcar_i2c_priv *priv)
+static int rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
 {
-        rcar_i2c_write(priv, ICCCR, priv->icccr);
-}
+        int read = !!rcar_i2c_is_recv(priv);
 
-/*
- *              status functions
- */
-static u32 rcar_i2c_status_get(struct rcar_i2c_priv *priv)
-{
-        return rcar_i2c_read(priv, ICMSR);
-}
-
-#define rcar_i2c_status_clear(priv) rcar_i2c_status_bit_clear(priv, 0xffffffff)
-static void rcar_i2c_status_bit_clear(struct rcar_i2c_priv *priv, u32 bit)
-{
-        rcar_i2c_write(priv, ICMSR, ~bit);
-}
-
-/*
- *              recv/send functions
- */
-static int rcar_i2c_recv(struct rcar_i2c_priv *priv)
-{
-        rcar_i2c_set_addr(priv, 1);
-        rcar_i2c_status_clear(priv);
-        rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_ADDR);
-        rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_RECV);
-
-        return 0;
-}
-
-static int rcar_i2c_send(struct rcar_i2c_priv *priv)
-{
-        int ret;
-
-        /*
-         * It should check bus status when send case
-         */
-        ret = rcar_i2c_bus_barrier(priv);
-        if (ret < 0)
-                return ret;
-
-        rcar_i2c_set_addr(priv, 0);
-        rcar_i2c_status_clear(priv);
-        rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_ADDR);
-        rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_SEND);
+        rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read);
+        rcar_i2c_write(priv, ICMSR, 0);
+        rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
+        rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
 
         return 0;
 }
 
-#define rcar_i2c_send_restart(priv) rcar_i2c_status_bit_clear(priv, (MAT | MDE))
-#define rcar_i2c_recv_restart(priv) rcar_i2c_status_bit_clear(priv, (MAT | MDR))
-
 /*
  *              interrupt functions
  */
@@ -386,7 +275,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
          * goto data phase.
          */
         if (msr & MAT)
-                rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA);
+                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
 
         if (priv->pos < msg->len) {
                 /*
@@ -414,7 +303,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
                          * prepare stop condition here.
                          * ID_DONE will be set on STOP irq.
                          */
-                        rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
+                        rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
                 else
                         /*
                          * If current msg is _NOT_ last msg,
@@ -425,7 +314,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
                         return ID_DONE;
         }
 
-        rcar_i2c_send_restart(priv);
+        rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
 
         return 0;
 }
@@ -462,11 +351,11 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
          * otherwise, go to DATA phase.
          */
         if (priv->pos + 1 >= msg->len)
-                rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
+                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
         else
-                rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA);
+                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
 
-        rcar_i2c_recv_restart(priv);
+        rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
 
         return 0;
 }
@@ -474,53 +363,31 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
 static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 {
         struct rcar_i2c_priv *priv = ptr;
-        struct device *dev = rcar_i2c_priv_to_dev(priv);
         u32 msr;
 
-        /*-------------- spin lock -----------------*/
-        spin_lock(&priv->lock);
+        msr = rcar_i2c_read(priv, ICMSR);
 
-        msr = rcar_i2c_status_get(priv);
-
-        /*
-         * Arbitration lost
-         */
+        /* Arbitration lost */
         if (msr & MAL) {
-                /*
-                 * CAUTION
-                 *
-                 * When arbitration lost, device become _slave_ mode.
-                 */
-                dev_dbg(dev, "Arbitration Lost\n");
                 rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
                 goto out;
         }
 
-        /*
-         * Stop
-         */
+        /* Stop */
         if (msr & MST) {
-                dev_dbg(dev, "Stop\n");
                 rcar_i2c_flags_set(priv, ID_DONE);
                 goto out;
         }
 
-        /*
-         * Nack
-         */
+        /* Nack */
         if (msr & MNR) {
-                dev_dbg(dev, "Nack\n");
-
                 /* go to stop phase */
-                rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
-                rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_STOP);
+                rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
+                rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
                 rcar_i2c_flags_set(priv, ID_NACK);
                 goto out;
         }
 
-        /*
-         * recv/send
-         */
         if (rcar_i2c_is_recv(priv))
                 rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
         else
@@ -528,14 +395,11 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 
 out:
         if (rcar_i2c_flags_has(priv, ID_DONE)) {
-                rcar_i2c_irq_mask(priv, RCAR_IRQ_CLOSE);
-                rcar_i2c_status_clear(priv);
+                rcar_i2c_write(priv, ICMIER, 0);
+                rcar_i2c_write(priv, ICMSR, 0);
                 wake_up(&priv->wait);
         }
 
-        spin_unlock(&priv->lock);
-        /*-------------- spin unlock -----------------*/
-
         return IRQ_HANDLED;
 }
 
@@ -545,24 +409,24 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 {
         struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
         struct device *dev = rcar_i2c_priv_to_dev(priv);
-        unsigned long flags;
         int i, ret, timeout;
 
         pm_runtime_get_sync(dev);
 
-        /*-------------- spin lock -----------------*/
-        spin_lock_irqsave(&priv->lock, flags);
-
         rcar_i2c_init(priv);
-        rcar_i2c_clock_start(priv);
+        /* start clock */
+        rcar_i2c_write(priv, ICCCR, priv->icccr);
 
-        spin_unlock_irqrestore(&priv->lock, flags);
-        /*-------------- spin unlock -----------------*/
+        ret = rcar_i2c_bus_barrier(priv);
+        if (ret < 0)
+                goto out;
 
-        ret = -EINVAL;
         for (i = 0; i < num; i++) {
-                /*-------------- spin lock -----------------*/
-                spin_lock_irqsave(&priv->lock, flags);
+                /* This HW can't send STOP after address phase */
+                if (msgs[i].len == 0) {
+                        ret = -EOPNOTSUPP;
+                        break;
+                }
 
                 /* init each data */
                 priv->msg       = &msgs[i];
@@ -571,21 +435,11 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
                 if (priv->msg == &msgs[num - 1])
                         rcar_i2c_flags_set(priv, ID_LAST_MSG);
 
-                /* start send/recv */
-                if (rcar_i2c_is_recv(priv))
-                        ret = rcar_i2c_recv(priv);
-                else
-                        ret = rcar_i2c_send(priv);
-
-                spin_unlock_irqrestore(&priv->lock, flags);
-                /*-------------- spin unlock -----------------*/
+                ret = rcar_i2c_prepare_msg(priv);
 
                 if (ret < 0)
                         break;
 
-                /*
-                 * wait result
-                 */
                 timeout = wait_event_timeout(priv->wait,
                                              rcar_i2c_flags_has(priv, ID_DONE),
                                              5 * HZ);
@@ -594,9 +448,6 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
                         break;
                 }
 
-                /*
-                 * error handling
-                 */
                 if (rcar_i2c_flags_has(priv, ID_NACK)) {
                         ret = -ENXIO;
                         break;
@@ -614,7 +465,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
                 ret = i + 1; /* The number of transfer */
         }
-
+out:
         pm_runtime_put(dev);
 
         if (ret < 0 && ret != -ENXIO)
@@ -625,7 +476,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
 static u32 rcar_i2c_func(struct i2c_adapter *adap)
 {
-        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+        /* This HW can't do SMBUS_QUICK and NOSTART */
+        return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 }
 
 static const struct i2c_algorithm rcar_i2c_algo = {
@@ -639,6 +491,9 @@ static const struct of_device_id rcar_i2c_dt_ids[] = {
         { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
         { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
         { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
+        { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
+        { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
+        { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
         {},
 };
 MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
@@ -651,13 +506,11 @@ static int rcar_i2c_probe(struct platform_device *pdev)
         struct resource *res;
         struct device *dev = &pdev->dev;
         u32 bus_speed;
-        int ret;
+        int irq, ret;
 
         priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
-        if (!priv) {
-                dev_err(dev, "no mem for private data\n");
+        if (!priv)
                 return -ENOMEM;
-        }
 
         priv->clk = devm_clk_get(dev, NULL);
         if (IS_ERR(priv->clk)) {
@@ -685,9 +538,8 @@ static int rcar_i2c_probe(struct platform_device *pdev)
         if (IS_ERR(priv->io))
                 return PTR_ERR(priv->io);
 
-        priv->irq = platform_get_irq(pdev, 0);
+        irq = platform_get_irq(pdev, 0);
         init_waitqueue_head(&priv->wait);
-        spin_lock_init(&priv->lock);
 
         adap                    = &priv->adap;
         adap->nr                = pdev->id;
@@ -699,10 +551,10 @@ static int rcar_i2c_probe(struct platform_device *pdev)
         i2c_set_adapdata(adap, priv);
         strlcpy(adap->name, pdev->name, sizeof(adap->name));
 
-        ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0,
+        ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0,
                                dev_name(dev), priv);
         if (ret < 0) {
-                dev_err(dev, "cannot get irq %d\n", priv->irq);
+                dev_err(dev, "cannot get irq %d\n", irq);
                 return ret;
         }
 
@@ -752,6 +604,6 @@ static struct platform_driver rcar_i2c_driver = {
 
 module_platform_driver(rcar_i2c_driver);
 
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");