i2c-omap: Enable I2C wakeups for 34xx

I2C_WE registers were not configured, which caused huge delays in
I2C operations while cpu idle was enabled and omap entered WFI.

This patch enables all I2C wakeup sources.

Signed-off-by: Kalle Jokiniemi <ext-kalle.jokiniemi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index b20235415878..96f3bedb2799 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -52,6 +52,8 @@
 #define OMAP_I2C_IE_REG                 0x04
 #define OMAP_I2C_STAT_REG               0x08
 #define OMAP_I2C_IV_REG                 0x0c
+/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
+#define OMAP_I2C_WE_REG                 0x0c
 #define OMAP_I2C_SYSS_REG               0x10
 #define OMAP_I2C_BUF_REG                0x14
 #define OMAP_I2C_CNT_REG                0x18
@@ -89,6 +91,24 @@
 #define OMAP_I2C_STAT_NACK      (1 << 1)        /* No ack interrupt enable */
 #define OMAP_I2C_STAT_AL        (1 << 0)        /* Arbitration lost int ena */
 
+/* I2C WE wakeup enable register */
+#define OMAP_I2C_WE_XDR_WE      (1 << 14)       /* TX drain wakup */
+#define OMAP_I2C_WE_RDR_WE      (1 << 13)       /* RX drain wakeup */
+#define OMAP_I2C_WE_AAS_WE      (1 << 9)        /* Address as slave wakeup*/
+#define OMAP_I2C_WE_BF_WE       (1 << 8)        /* Bus free wakeup */
+#define OMAP_I2C_WE_STC_WE      (1 << 6)        /* Start condition wakeup */
+#define OMAP_I2C_WE_GC_WE       (1 << 5)        /* General call wakeup */
+#define OMAP_I2C_WE_DRDY_WE     (1 << 3)        /* TX/RX data ready wakeup */
+#define OMAP_I2C_WE_ARDY_WE     (1 << 2)        /* Reg access ready wakeup */
+#define OMAP_I2C_WE_NACK_WE     (1 << 1)        /* No acknowledgment wakeup */
+#define OMAP_I2C_WE_AL_WE       (1 << 0)        /* Arbitration lost wakeup */
+
+#define OMAP_I2C_WE_ALL         (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
+                                OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
+                                OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
+                                OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
+                                OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
+
 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
 #define OMAP_I2C_BUF_RDMA_EN    (1 << 15)       /* RX DMA channel enable */
 #define OMAP_I2C_BUF_RXFIF_CLR  (1 << 14)       /* RX FIFO Clear */
@@ -279,6 +299,13 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
                               __ffs(SYSC_CLOCKACTIVITY_MASK));
 
                         omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, v);
+                        /*
+                         * 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);
 
                 }
         }