i2c-omap: Don't write IE state in unidle if 0

[pandora-kernel.git] / drivers / i2c / busses / i2c-omap.c

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 827da08..a64a192 100644 (file)
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -178,6 +178,12 @@ struct omap_i2c_dev {
        unsigned                b_hw:1;         /* bad h/w fixes */
        unsigned                idle:1;
        u16                     iestate;        /* Saved interrupt register */
+       u16                     pscstate;
+       u16                     scllstate;
+       u16                     sclhstate;
+       u16                     bufstate;
+       u16                     syscstate;
+       u16                     westate;
 };
 
 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
@@ -230,7 +236,22 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 
        clk_enable(dev->iclk);
        clk_enable(dev->fclk);
+       if (cpu_is_omap34xx()) {
+               omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
+               omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
+               omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
+               omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
+               omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
+               omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate);
+               omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
+               omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+       }
        dev->idle = 0;
+
+       /*
+        * Don't write to this register if the IE state is 0 as it can
+        * cause deadlock.
+        */
        if (dev->iestate)
                omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
 }
@@ -258,7 +279,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
 
 static int omap_i2c_init(struct omap_i2c_dev *dev)
 {
-       u16 psc = 0, scll = 0, sclh = 0;
+       u16 psc = 0, scll = 0, sclh = 0, buf = 0;
        u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
        unsigned long fclk_rate = 12000000;
        unsigned long timeout;
@@ -287,24 +308,22 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
                                           SYSC_AUTOIDLE_MASK);
 
                } else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
-                       u32 v;
-
-                       v = SYSC_AUTOIDLE_MASK;
-                       v |= SYSC_ENAWAKEUP_MASK;
-                       v |= (SYSC_IDLEMODE_SMART <<
+                       dev->syscstate = SYSC_AUTOIDLE_MASK;
+                       dev->syscstate |= SYSC_ENAWAKEUP_MASK;
+                       dev->syscstate |= (SYSC_IDLEMODE_SMART <<
                              __ffs(SYSC_SIDLEMODE_MASK));
-                       v |= (SYSC_CLOCKACTIVITY_FCLK <<
+                       dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
                              __ffs(SYSC_CLOCKACTIVITY_MASK));
 
-                       omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, v);
+                       omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
+                                                       dev->syscstate);
                        /*
                         * Enabling all wakup sources to stop I2C freezing on
                         * WFI instruction.
                         * REVISIT: Some wkup sources might not be needed.
                         */
-                       omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
-                                                       OMAP_I2C_WE_ALL);
-
+                       dev->westate = OMAP_I2C_WE_ALL;
+                       omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
                }
        }
        omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
@@ -394,23 +413,28 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
        omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
        omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
 
-       if (dev->fifo_size)
-               /* Note: setup required fifo size - 1 */
-               omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG,
-                                       (dev->fifo_size - 1) << 8 | /* RTRSH */
-                                       OMAP_I2C_BUF_RXFIF_CLR |
-                                       (dev->fifo_size - 1) | /* XTRSH */
-                                       OMAP_I2C_BUF_TXFIF_CLR);
+       if (dev->fifo_size) {
+               /* Note: setup required fifo size - 1. RTRSH and XTRSH */
+               buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
+                       (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
+               omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
+       }
 
        /* Take the I2C module out of reset: */
        omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
 
        /* Enable interrupts */
-       omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
-                       (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
+       dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
                        OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
                        OMAP_I2C_IE_AL)  | ((dev->fifo_size) ?
-                               (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0));
+                               (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
+       omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
+       if (cpu_is_omap34xx()) {
+               dev->pscstate = psc;
+               dev->scllstate = scll;
+               dev->sclhstate = sclh;
+               dev->bufstate = buf;
+       }
        return 0;
 }