From: David Daney <dda...@caviumnetworks.com>

cn78XX has a different interrupt architecture, so we have to manage
the interrupts differently.

Signed-off-by: David Daney <dda...@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglau...@cavium.com>
---
 drivers/i2c/busses/i2c-octeon.c | 156 ++++++++++++++++++++++++++++++++++------
 1 file changed, 136 insertions(+), 20 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index d48456a..0b28d8c 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -15,6 +15,7 @@
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/atomic.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -109,11 +110,18 @@ struct octeon_i2c {
        wait_queue_head_t       queue;
        struct i2c_adapter      adap;
        int                     irq;
+       int                     hlc_irq;        /* For cn7890 only */
        u32                     twsi_freq;
        int                     sys_freq;
        void __iomem            *twsi_base;
        struct device           *dev;
        bool                    hlc_enabled;
+       void                    (*int_en)       (struct octeon_i2c *);
+       void                    (*int_dis)      (struct octeon_i2c *);
+       void                    (*hlc_int_en)   (struct octeon_i2c *);
+       void                    (*hlc_int_dis)  (struct octeon_i2c *);
+       atomic_t                int_en_cnt;
+       atomic_t                hlc_int_en_cnt;
 };
 
 static int reset_how;
@@ -215,6 +223,58 @@ static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
 }
 
 /**
+ * octeon_i2c_int_enable78 - enable the CORE interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in the
+ * SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
+{
+       atomic_inc_return(&i2c->int_en_cnt);
+       enable_irq(i2c->irq);
+}
+
+static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
+{
+       int count;
+
+       /*
+        * The interrupt can be disabled in two places, but we only
+        * want to make the disable_irq_nosync() call once, so keep
+        * track with the atomic variable.
+        */
+       count = atomic_dec_if_positive(cnt);
+       if (count >= 0)
+               disable_irq_nosync(irq);
+}
+
+/* disable the CORE interrupt */
+static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
+{
+       __octeon_i2c_irq_disable(&i2c->int_en_cnt, i2c->irq);
+}
+
+/**
+ * octeon_i2c_hlc_int_enable78 - enable the ST interrupt
+ * @i2c: The struct octeon_i2c
+ *
+ * The interrupt will be asserted when there is non-STAT_IDLE state in
+ * the SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
+{
+       atomic_inc_return(&i2c->hlc_int_en_cnt);
+       enable_irq(i2c->hlc_irq);
+}
+
+/* disable the ST interrupt */
+static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
+{
+       __octeon_i2c_irq_disable(&i2c->hlc_int_en_cnt, i2c->hlc_irq);
+}
+
+/**
  * bitbang_unblock - unblock the bus
  * @i2c: The struct octeon_i2c
  *
@@ -251,7 +311,18 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
 {
        struct octeon_i2c *i2c = dev_id;
 
-       octeon_i2c_int_disable(i2c);
+       i2c->int_dis(i2c);
+       wake_up(&i2c->queue);
+
+       return IRQ_HANDLED;
+}
+
+/* interrupt service routine */
+static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
+{
+       struct octeon_i2c *i2c = dev_id;
+
+       i2c->hlc_int_dis(i2c);
        wake_up(&i2c->queue);
 
        return IRQ_HANDLED;
@@ -277,10 +348,10 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
        long result;
 
-       octeon_i2c_int_enable(i2c);
+       i2c->int_en(i2c);
        result = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
                                    i2c->adap.timeout);
-       octeon_i2c_int_disable(i2c);
+       i2c->int_dis(i2c);
        if (!result) {
                dev_dbg(i2c->dev, "%s: timeout\n", __func__);
                return -ETIMEDOUT;
@@ -300,8 +371,8 @@ static int octeon_i2c_enable_hlc(struct octeon_i2c *i2c)
 
        if (i2c->hlc_enabled)
                return 0;
-       else
-               i2c->hlc_enabled = true;
+
+       i2c->hlc_enabled = true;
 
        while (1) {
                val = octeon_i2c_read_ctl(i2c) & (TWSI_CTL_STA | TWSI_CTL_STP);
@@ -635,11 +706,10 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
        int result;
 
-       octeon_i2c_hlc_int_enable(i2c);
+       i2c->hlc_int_en(i2c);
        result = wait_event_interruptible_timeout(i2c->queue,
-                                                 
octeon_i2c_hlc_test_ready(i2c),
-                                                 i2c->adap.timeout);
-       octeon_i2c_int_disable(i2c);
+                       octeon_i2c_hlc_test_ready(i2c), i2c->adap.timeout);
+       i2c->hlc_int_dis(i2c);
        if (!result)
                octeon_i2c_hlc_int_clear(i2c);
 
@@ -972,14 +1042,26 @@ static void octeon_i2c_setclock(struct octeon_i2c *i2c)
 static int octeon_i2c_probe(struct platform_device *pdev)
 {
        struct device_node *node = pdev->dev.of_node;
-       int irq, result = 0;
+       int irq, hlc_irq = 0, result = 0;
        struct resource *res_mem;
        struct octeon_i2c *i2c;
-
-       /* All adaptors have an irq.  */
-       irq = platform_get_irq(pdev, 0);
-       if (irq < 0)
-               return irq;
+       bool cn78xx_style;
+
+       cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
+       if (cn78xx_style) {
+               hlc_irq = platform_get_irq(pdev, 0);
+               if (hlc_irq < 0)
+                       return hlc_irq;
+
+               irq = platform_get_irq(pdev, 2);
+               if (irq < 0)
+                       return irq;
+       } else {
+               /* All adaptors have an irq.  */
+               irq = platform_get_irq(pdev, 0);
+               if (irq < 0)
+                       return irq;
+       }
 
        i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
        if (!i2c) {
@@ -1022,11 +1104,44 @@ static int octeon_i2c_probe(struct platform_device 
*pdev)
        init_waitqueue_head(&i2c->queue);
        i2c->irq = irq;
 
-       result = devm_request_irq(&pdev->dev, i2c->irq,
-                                 octeon_i2c_isr, 0, DRV_NAME, i2c);
-       if (result < 0) {
-               dev_err(i2c->dev, "failed to attach interrupt\n");
-               goto out;
+       if (cn78xx_style) {
+               i2c->hlc_irq = hlc_irq;
+
+               i2c->int_en = octeon_i2c_int_enable78;
+               i2c->int_dis = octeon_i2c_int_disable78;
+               i2c->hlc_int_en = octeon_i2c_hlc_int_enable78;
+               i2c->hlc_int_dis = octeon_i2c_hlc_int_disable78;
+
+               irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
+               irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);
+
+               result = devm_request_irq(&pdev->dev, i2c->irq,
+                                         octeon_i2c_isr, 0, DRV_NAME, i2c);
+
+               if (result < 0) {
+                       dev_err(i2c->dev, "failed to attach interrupt\n");
+                       goto out;
+               }
+               result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
+                                         octeon_i2c_hlc_isr78, 0,
+                                         DRV_NAME, i2c);
+
+               if (result < 0) {
+                       dev_err(i2c->dev, "failed to attach interrupt\n");
+                       goto out;
+               }
+       } else {
+               i2c->int_en = octeon_i2c_int_enable;
+               i2c->int_dis = octeon_i2c_int_disable;
+               i2c->hlc_int_en = octeon_i2c_hlc_int_enable;
+               i2c->hlc_int_dis = octeon_i2c_int_disable;
+
+               result = devm_request_irq(&pdev->dev, i2c->irq,
+                                         octeon_i2c_isr, 0, DRV_NAME, i2c);
+               if (result < 0) {
+                       dev_err(i2c->dev, "failed to attach interrupt\n");
+                       goto out;
+               }
        }
 
        result = octeon_i2c_initlowlevel(i2c);
@@ -1067,6 +1182,7 @@ static int octeon_i2c_remove(struct platform_device *pdev)
 
 static const struct of_device_id octeon_i2c_match[] = {
        {       .compatible = "cavium,octeon-3860-twsi",        },
+       {       .compatible = "cavium,octeon-7890-twsi",        },
        {},
 };
 MODULE_DEVICE_TABLE(of, octeon_i2c_match);
-- 
1.9.1

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