ppc4xx_i2c: Implement directcntl register

As well as being able to generate its own i2c transactions, the ppc4xx
i2c controller has a DIRECTCNTL register which allows explicit control
of the i2c lines.

Using this register an OS can directly bitbang i2c operations. In
order to let emulated i2c devices respond to this, we need to wire up
the DIRECTCNTL register to qemu's bitbanged i2c handling code.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/default-configs/ppc-softmmu.mak b/default-configs/ppc-softmmu.mak
index abeeb0418aae7f334321e4f1a482b95b64f4ebb0..851b4afc2137c547a3cdfba922398da14e913ee6 100644 (file)
--- a/default-configs/ppc-softmmu.mak
+++ b/default-configs/ppc-softmmu.mak
@@ -26,6 +26,7 @@ CONFIG_USB_EHCI_SYSBUS=y
 CONFIG_SM501=y
 CONFIG_IDE_SII3112=y
 CONFIG_I2C=y
+CONFIG_BITBANG_I2C=y
 
 # For Macs
 CONFIG_MAC=y

diff --git a/default-configs/ppcemb-softmmu.mak b/default-configs/ppcemb-softmmu.mak
index 67d18b2e0e1e95cd0514d9a6597237bc6935df46..37af1930b33cb6d70c83fc2d024a2982a4566879 100644 (file)
--- a/default-configs/ppcemb-softmmu.mak
+++ b/default-configs/ppcemb-softmmu.mak
@@ -19,3 +19,4 @@ CONFIG_USB_EHCI_SYSBUS=y
 CONFIG_SM501=y
 CONFIG_IDE_SII3112=y
 CONFIG_I2C=y
+CONFIG_BITBANG_I2C=y

diff --git a/hw/i2c/ppc4xx_i2c.c b/hw/i2c/ppc4xx_i2c.c
index 4e0aaae1fc3c5ffa63d951b197b355e74bda2aec..fca80d695a43d1205832a4dc1c0aedb61d4d979f 100644 (file)
--- a/hw/i2c/ppc4xx_i2c.c
+++ b/hw/i2c/ppc4xx_i2c.c
@@ -30,6 +30,7 @@
 #include "cpu.h"
 #include "hw/hw.h"
 #include "hw/i2c/ppc4xx_i2c.h"
+#include "bitbang_i2c.h"
 
 #define PPC4xx_I2C_MEM_SIZE 18
 
@@ -46,6 +47,11 @@
 
 #define IIC_XTCNTLSS_SRST   (1 << 0)
 
+#define IIC_DIRECTCNTL_SDAC (1 << 3)
+#define IIC_DIRECTCNTL_SCLC (1 << 2)
+#define IIC_DIRECTCNTL_MSDA (1 << 1)
+#define IIC_DIRECTCNTL_MSCL (1 << 0)
+
 static void ppc4xx_i2c_reset(DeviceState *s)
 {
     PPC4xxI2CState *i2c = PPC4xx_I2C(s);
@@ -289,7 +295,12 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
         i2c->xtcntlss = value;
         break;
     case 16:
-        i2c->directcntl = value & 0x7;
+        i2c->directcntl = value & (IIC_DIRECTCNTL_SDAC & IIC_DIRECTCNTL_SCLC);
+        i2c->directcntl |= (value & IIC_DIRECTCNTL_SCLC ? 1 : 0);
+        bitbang_i2c_set(i2c->bitbang, BITBANG_I2C_SCL,
+                        i2c->directcntl & IIC_DIRECTCNTL_MSCL);
+        i2c->directcntl |= bitbang_i2c_set(i2c->bitbang, BITBANG_I2C_SDA,
+                               (value & IIC_DIRECTCNTL_SDAC) != 0) << 1;
         break;
     default:
         if (addr < PPC4xx_I2C_MEM_SIZE) {
@@ -322,6 +333,7 @@ static void ppc4xx_i2c_init(Object *o)
     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
     s->bus = i2c_init_bus(DEVICE(s), "i2c");
+    s->bitbang = bitbang_i2c_init(s->bus);
 }
 
 static void ppc4xx_i2c_class_init(ObjectClass *klass, void *data)

diff --git a/include/hw/i2c/ppc4xx_i2c.h b/include/hw/i2c/ppc4xx_i2c.h
index e4b6ded855c2f1712e0468f3d135d3ad8264dd59..ea6c8e1a586c0b171a245e85f4c0537b20721232 100644 (file)
--- a/include/hw/i2c/ppc4xx_i2c.h
+++ b/include/hw/i2c/ppc4xx_i2c.h
@@ -31,6 +31,9 @@
 #include "hw/sysbus.h"
 #include "hw/i2c/i2c.h"
 
+/* from hw/i2c/bitbang_i2c.h */
+typedef struct bitbang_i2c_interface bitbang_i2c_interface;
+
 #define TYPE_PPC4xx_I2C "ppc4xx-i2c"
 #define PPC4xx_I2C(obj) OBJECT_CHECK(PPC4xxI2CState, (obj), TYPE_PPC4xx_I2C)
 
@@ -42,6 +45,7 @@ typedef struct PPC4xxI2CState {
     I2CBus *bus;
     qemu_irq irq;
     MemoryRegion iomem;
+    bitbang_i2c_interface *bitbang;
     uint8_t mdata;
     uint8_t lmadr;
     uint8_t hmadr;