Merge tag 'backport/v3.14.24-ltsi-rc1/phy-rcar-gen2-usb-to-v3.15' into backport/v3...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / i2c / busses / i2c-rcar.c

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 71e88d0..d826e82 100644 (file)
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -34,6 +34,7 @@
 #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 */
@@ -75,8 +76,8 @@
 #define RCAR_IRQ_RECV  (MNR | MAL | MST | MAT | MDR)
 #define RCAR_IRQ_STOP  (MST)
 
-#define RCAR_IRQ_ACK_SEND      (~(MAT | MDE))
-#define RCAR_IRQ_ACK_RECV      (~(MAT | MDR))
+#define RCAR_IRQ_ACK_SEND      (~(MAT | MDE) & 0xFF)
+#define RCAR_IRQ_ACK_RECV      (~(MAT | MDR) & 0xFF)
 
 #define ID_LAST_MSG    (1 << 0)
 #define ID_IOERROR     (1 << 1)
@@ -95,6 +96,7 @@ struct rcar_i2c_priv {
        struct i2c_msg  *msg;
        struct clk *clk;
 
+       spinlock_t lock;
        wait_queue_head_t wait;
 
        int pos;
@@ -193,7 +195,7 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
         */
        rate = clk_get_rate(priv->clk);
        cdf = rate / 20000000;
-       if (cdf >= 1 << cdf_width) {
+       if (cdf >= 1U << cdf_width) {
                dev_err(dev, "Input clock %lu too high\n", rate);
                return -EIO;
        }
@@ -243,7 +245,7 @@ scgd_find:
        return 0;
 }
 
-static int rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
+static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
 {
        int read = !!rcar_i2c_is_recv(priv);
 
@@ -251,8 +253,6 @@ static int rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
        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;
 }
 
 /*
@@ -363,22 +363,27 @@ 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;
+       irqreturn_t result = IRQ_HANDLED;
        u32 msr;
 
+       /*-------------- spin lock -----------------*/
+       spin_lock(&priv->lock);
+
        msr = rcar_i2c_read(priv, ICMSR);
 
+       /* Only handle interrupts that are currently enabled */
+       msr &= rcar_i2c_read(priv, ICMIER);
+       if (!msr) {
+               result = IRQ_NONE;
+               goto exit;
+       }
+
        /* Arbitration lost */
        if (msr & MAL) {
                rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
                goto out;
        }
 
-       /* Stop */
-       if (msr & MST) {
-               rcar_i2c_flags_set(priv, ID_DONE);
-               goto out;
-       }
-
        /* Nack */
        if (msr & MNR) {
                /* go to stop phase */
@@ -388,6 +393,12 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
                goto out;
        }
 
+       /* Stop */
+       if (msr & MST) {
+               rcar_i2c_flags_set(priv, ID_DONE);
+               goto out;
+       }
+
        if (rcar_i2c_is_recv(priv))
                rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
        else
@@ -400,7 +411,11 @@ out:
                wake_up(&priv->wait);
        }
 
-       return IRQ_HANDLED;
+exit:
+       spin_unlock(&priv->lock);
+       /*-------------- spin unlock -----------------*/
+
+       return result;
 }
 
 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
@@ -409,14 +424,21 @@ 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);
        /* 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;
@@ -428,17 +450,20 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
                        break;
                }
 
+               /*-------------- spin lock -----------------*/
+               spin_lock_irqsave(&priv->lock, flags);
+
                /* init each data */
                priv->msg       = &msgs[i];
                priv->pos       = 0;
                priv->flags     = 0;
-               if (priv->msg == &msgs[num - 1])
+               if (i == num - 1)
                        rcar_i2c_flags_set(priv, ID_LAST_MSG);
 
-               ret = rcar_i2c_prepare_msg(priv);
+               rcar_i2c_prepare_msg(priv);
 
-               if (ret < 0)
-                       break;
+               spin_unlock_irqrestore(&priv->lock, flags);
+               /*-------------- spin unlock -----------------*/
 
                timeout = wait_event_timeout(priv->wait,
                                             rcar_i2c_flags_has(priv, ID_DONE),
@@ -509,10 +534,8 @@ static int rcar_i2c_probe(struct platform_device *pdev)
        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)) {
@@ -542,14 +565,15 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 
        irq = platform_get_irq(pdev, 0);
        init_waitqueue_head(&priv->wait);
-
-       adap                    = &priv->adap;
-       adap->nr                = pdev->id;
-       adap->algo              = &rcar_i2c_algo;
-       adap->class             = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLASS_DEPRECATED;
-       adap->retries           = 3;
-       adap->dev.parent        = dev;
-       adap->dev.of_node       = dev->of_node;
+       spin_lock_init(&priv->lock);
+
+       adap = &priv->adap;
+       adap->nr = pdev->id;
+       adap->algo = &rcar_i2c_algo;
+       adap->class = I2C_CLASS_DEPRECATED;
+       adap->retries = 3;
+       adap->dev.parent = dev;
+       adap->dev.of_node = dev->of_node;
        i2c_set_adapdata(adap, priv);
        strlcpy(adap->name, pdev->name, sizeof(adap->name));