[Qemu-devel] [PATCH] PIIX4 SMBus host, EEPROM device emulation

["Ed Swierk" <eswierk@arastra.com>]

[-- Attachment #1: Type: text/plain, Size: 677 bytes --]

The attached patch adds SMBus host support to the emulated PIIX4 power
management device (acpi.c), and adds an emulated serial EEPROM device
accessible via the SMBus interface.

I tried to follow the Intel 82371AB spec for the SMBus support; the
interface should be generic enough to implement a variety of
SMBus-compliant devices.

The EEPROM device can use a file for persistent storage
(smbus_eeprom.bin in the BIOS directory). If this file does not exist,
a temporary buffer is used instead.

I tested the devices with Linux using the i2c-piix4 host driver and
the eeprom chip driver. I have no idea what will happen on other OSes.

Comments and suggestions welcome.

--Ed

[-- Attachment #2: qemu-piix4-smbus-eeprom.patch --]
[-- Type: text/x-patch, Size: 13967 bytes --]

Index: qemu-0.8.2/hw/acpi.c
===================================================================
--- qemu-0.8.2.orig/hw/acpi.c
+++ qemu-0.8.2/hw/acpi.c
@@ -27,6 +27,7 @@
 #define PM_IO_BASE        0xb000
 #define SMI_CMD_IO_ADDR   0xb040
 #define ACPI_DBG_IO_ADDR  0xb044
+#define SMB_IO_BASE     0xb100
 
 typedef struct PIIX4PMState {
     PCIDevice dev;
@@ -35,6 +36,15 @@ typedef struct PIIX4PMState {
     uint16_t pmcntrl;
     QEMUTimer *tmr_timer;
     int64_t tmr_overflow_time;
+    SMBusDevice *smb_dev[128];
+    uint8_t smb_stat;
+    uint8_t smb_ctl;
+    uint8_t smb_cmd;
+    uint8_t smb_addr;
+    uint8_t smb_data0;
+    uint8_t smb_data1;
+    uint8_t smb_data[32];
+    uint8_t smb_index;
 } PIIX4PMState;
 
 #define RTC_EN (1 << 10)
@@ -46,8 +56,6 @@ typedef struct PIIX4PMState {
 
 #define SUS_EN (1 << 13)
 
-/* Note: only used for ACPI bios init. Could be deleted when ACPI init
-   is integrated in Bochs BIOS */
 static PIIX4PMState *piix4_pm_state;
 
 static uint32_t get_pmtmr(PIIX4PMState *s)
@@ -218,13 +226,163 @@ static void acpi_dbg_writel(void *opaque
 #endif
 }
 
+static void smb_transaction(PIIX4PMState *s)
+{
+    uint8_t prot = (s->smb_ctl >> 2) & 0x07;
+    uint8_t read = s->smb_addr & 0x01;
+    uint8_t cmd = s->smb_cmd;
+    uint8_t addr = s->smb_addr >> 1;
+    SMBusDevice *dev = s->smb_dev[addr];
+
+#ifdef DEBUG
+    printf("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);
+#endif
+    if (!dev) goto error;
+
+    switch(prot) {
+    case 0x0:
+        if (!dev->quick_cmd) goto error;
+        (*dev->quick_cmd)(dev, read);
+        break;
+    case 0x1:
+        if (read) {
+            if (!dev->receive_byte) goto error;
+            s->smb_data0 = (*dev->receive_byte)(dev);
+        }
+        else {
+            if (!dev->send_byte) goto error;
+            (*dev->send_byte)(dev, cmd);
+        }
+        break;
+    case 0x2:
+        if (read) {
+            if (!dev->read_byte) goto error;
+            s->smb_data0 = (*dev->read_byte)(dev, cmd);
+        }
+        else {
+            if (!dev->write_byte) goto error;
+            (*dev->write_byte)(dev, cmd, s->smb_data0);
+        }
+        break;
+    case 0x3:
+        if (read) {
+            uint16_t val;
+            if (!dev->read_word) goto error;
+            val = (*dev->read_word)(dev, cmd);
+            s->smb_data0 = val;
+            s->smb_data1 = val >> 8;
+        }
+        else {
+            if (!dev->write_word) goto error;
+            (*dev->write_word)(dev, cmd, (s->smb_data1 << 8) | s->smb_data0);
+        }
+        break;
+    case 0x5:
+        if (read) {
+            if (!dev->read_block) goto error;
+            s->smb_data0 = (*dev->read_block)(dev, cmd, s->smb_data);
+        }
+        else {
+            if (!dev->write_block) goto error;
+            (*dev->write_block)(dev, cmd, s->smb_data0, s->smb_data);
+        }
+        break;
+    default:
+        goto error;
+    }
+    return;
+
+  error:
+    s->smb_stat |= 0x04;
+}
+
+static void smb_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
+{
+    PIIX4PMState *s = opaque;
+    addr &= 0x3f;
+#ifdef DEBUG
+    printf("SMB writeb port=0x%04x val=0x%02x\n", addr, val);
+#endif
+    switch(addr) {
+    case 0x00: /* SMBHSTSTS */
+        s->smb_stat = 0;
+        s->smb_index = 0;
+        break;
+    case 0x02: /* SMBHSTCNT */
+        s->smb_ctl = val;
+        if (val & 0x40)
+            smb_transaction(s);
+        break;
+    case 0x03: /* SMBHSTCMD */
+        s->smb_cmd = val;
+        break;
+    case 0x04: /* SMBHSTADD */
+        s->smb_addr = val;
+        break;
+    case 0x05: /* SMBHSTDAT0 */
+        s->smb_data0 = val;
+        break;
+    case 0x06: /* SMBHSTDAT1 */
+        s->smb_data1 = val;
+        break;
+    case 0x07: /* SMBBLKDAT */
+        s->smb_data[s->smb_index++] = val;
+        if (s->smb_index > 31)
+            s->smb_index = 0;
+        break;
+    default:
+        break;
+    }
+}
+
+static uint32_t smb_ioport_readb(void *opaque, uint32_t addr)
+{
+    PIIX4PMState *s = opaque;
+    uint32_t val;
+
+    addr &= 0x3f;
+    switch(addr) {
+    case 0x00: /* SMBHSTSTS */
+        val = s->smb_stat;
+        break;
+    case 0x02: /* SMBHSTCNT */
+        s->smb_index = 0;
+        val = s->smb_ctl & 0x1f;
+        break;
+    case 0x03: /* SMBHSTCMD */
+        val = s->smb_cmd;
+        break;
+    case 0x04: /* SMBHSTADD */
+        val = s->smb_addr;
+        break;
+    case 0x05: /* SMBHSTDAT0 */
+        val = s->smb_data0;
+        break;
+    case 0x06: /* SMBHSTDAT1 */
+        val = s->smb_data1;
+        break;
+    case 0x07: /* SMBBLKDAT */
+        val = s->smb_data[s->smb_index++];
+        if (s->smb_index > 31)
+            s->smb_index = 0;
+        break;
+    default:
+        val = 0;
+        break;
+    }
+#ifdef DEBUG
+    printf("SMB readb port=0x%04x val=0x%02x\n", addr, val);
+#endif
+    return val;
+}
+
 /* XXX: we still add it to the PIIX3 and we count on the fact that
    OSes are smart enough to accept this strange configuration */
 void piix4_pm_init(PCIBus *bus, int devfn)
 {
     PIIX4PMState *s;
     uint8_t *pci_conf;
-    uint32_t pm_io_base;
+    uint32_t pm_io_base, smb_io_base;
 
     s = (PIIX4PMState *)pci_register_device(bus,
                                          "PM", sizeof(PIIX4PMState),
@@ -259,10 +417,22 @@ void piix4_pm_init(PCIBus *bus, int devf
     pci_conf[0x67] = (serial_hds[0] != NULL ? 0x08 : 0) |
 	(serial_hds[1] != NULL ? 0x90 : 0);
 
+    smb_io_base = SMB_IO_BASE;
+    pci_conf[0x90] = smb_io_base | 1;
+    pci_conf[0x91] = smb_io_base >> 8;
+    pci_conf[0xd2] = 0x09;
+    register_ioport_write(smb_io_base, 64, 1, smb_ioport_writeb, s);
+    register_ioport_read(smb_io_base, 64, 1, smb_ioport_readb, s);
+
     s->tmr_timer = qemu_new_timer(vm_clock, pm_tmr_timer, s);
     piix4_pm_state = s;
 }
 
+void piix4_smbus_register_device(SMBusDevice *dev, uint8_t addr)
+{
+    piix4_pm_state->smb_dev[addr] = dev;
+}
+
 /* ACPI tables */
 /* XXX: move them in the Bochs BIOS ? */
 
Index: qemu-0.8.2/hw/smbus.h
===================================================================
--- /dev/null
+++ qemu-0.8.2/hw/smbus.h
@@ -0,0 +1,38 @@
+/*
+ * QEMU SMBus API
+ * 
+ * Copyright (c) 2007 Arastra, Inc.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+typedef struct SMBusDevice SMBusDevice;
+
+struct SMBusDevice {
+    uint8_t addr;
+    void (*quick_cmd)(SMBusDevice *dev, uint8_t read);
+    void (*send_byte)(SMBusDevice *dev, uint8_t val);
+    uint8_t (*receive_byte)(SMBusDevice *dev);
+    void (*write_byte)(SMBusDevice *dev, uint8_t cmd, uint8_t val);
+    uint8_t (*read_byte)(SMBusDevice *dev, uint8_t cmd);
+    void (*write_word)(SMBusDevice *dev, uint8_t cmd, uint16_t val);
+    uint16_t (*read_word)(SMBusDevice *dev, uint8_t cmd);
+    void (*write_block)(SMBusDevice *dev, uint8_t cmd, uint8_t len, uint8_t *buf);
+    uint8_t (*read_block)(SMBusDevice *dev, uint8_t cmd, uint8_t *buf);
+};
Index: qemu-0.8.2/hw/smbus_eeprom.c
===================================================================
--- /dev/null
+++ qemu-0.8.2/hw/smbus_eeprom.c
@@ -0,0 +1,94 @@
+/*
+ * QEMU SMBus EEPROM device
+ * 
+ * Copyright (c) 2007 Arastra, Inc.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "vl.h"
+
+//#define DEBUG
+
+typedef struct SMBusEEPROMDevice {
+    SMBusDevice dev;
+    uint8_t *data;
+    uint8_t offset;
+} SMBusEEPROMDevice;
+
+static void eeprom_quick_cmd(SMBusDevice *dev, uint8_t read)
+{
+#ifdef DEBUG
+    printf("eeprom_quick_cmd: addr=0x%02x read=%d\n", dev->addr, read);
+#endif
+}
+
+static void eeprom_send_byte(SMBusDevice *dev, uint8_t val)
+{
+    SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
+#ifdef DEBUG
+    printf("eeprom_send_byte: addr=0x%02x val=0x%02x\n", dev->addr, val);
+#endif
+    eeprom->offset = val;
+}
+
+static uint8_t eeprom_receive_byte(SMBusDevice *dev)
+{
+    SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
+    uint8_t val = eeprom->data[eeprom->offset++];
+#ifdef DEBUG
+    printf("eeprom_receive_byte: addr=0x%02x val=0x%02x\n", dev->addr, val);
+#endif
+    return val;
+}
+
+static void eeprom_write_byte(SMBusDevice *dev, uint8_t cmd, uint8_t val)
+{
+    SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
+#ifdef DEBUG
+    printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n", dev->addr,
+           cmd, val);
+#endif
+    eeprom->data[cmd] = val;
+}
+
+static uint8_t eeprom_read_byte(SMBusDevice *dev, uint8_t cmd)
+{
+    SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
+    uint8_t val = eeprom->data[cmd];
+#ifdef DEBUG
+    printf("eeprom_read_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n", dev->addr,
+           cmd, val);
+#endif
+    return val;
+}
+
+SMBusDevice *smbus_eeprom_device_init(uint8_t addr, uint8_t *buf)
+{
+    SMBusEEPROMDevice *eeprom = qemu_mallocz(sizeof(SMBusEEPROMDevice));
+    eeprom->dev.addr = addr;
+    eeprom->dev.quick_cmd = eeprom_quick_cmd;
+    eeprom->dev.send_byte = eeprom_send_byte;
+    eeprom->dev.receive_byte = eeprom_receive_byte;
+    eeprom->dev.write_byte = eeprom_write_byte;
+    eeprom->dev.read_byte = eeprom_read_byte;
+    eeprom->data = buf;
+    eeprom->offset = 0;
+    return (SMBusDevice *) eeprom;
+}
Index: qemu-0.8.2/vl.h
===================================================================
--- qemu-0.8.2.orig/vl.h
+++ qemu-0.8.2/vl.h
@@ -917,11 +917,17 @@ int pit_get_out(PITState *pit, int chann
 void pcspk_init(PITState *);
 int pcspk_audio_init(AudioState *);
 
+#include "hw/smbus.h"
+
 /* acpi.c */
 extern int acpi_enabled;
 void piix4_pm_init(PCIBus *bus, int devfn);
+void piix4_smbus_register_device(SMBusDevice *dev, uint8_t addr);
 void acpi_bios_init(void);
 
+/* smbus_eeprom.c */
+SMBusDevice *smbus_eeprom_device_init(uint8_t addr, uint8_t *buf);
+
 /* pc.c */
 extern QEMUMachine pc_machine;
 extern QEMUMachine isapc_machine;
Index: qemu-0.8.2/hw/pc.c
===================================================================
--- qemu-0.8.2.orig/hw/pc.c
+++ qemu-0.8.2/hw/pc.c
@@ -24,6 +24,7 @@
 #include "vl.h"
 
 #include <dlfcn.h> /* For dlopen of hw plugin shared libraries */
+#include <sys/mman.h>
 
 /* output Bochs bios info messages */
 //#define DEBUG_BIOS
@@ -32,6 +33,7 @@
 #define VGABIOS_FILENAME "vgabios.bin"
 #define VGABIOS_CIRRUS_FILENAME "vgabios-cirrus.bin"
 #define LINUX_BOOT_FILENAME "linux_boot.bin"
+#define SMBUS_EEPROM_FILENAME "smbus_eeprom.bin"
 
 #define KERNEL_LOAD_ADDR     0x00100000
 #define INITRD_LOAD_ADDR     0x00600000
@@ -863,7 +865,22 @@ static void pc_init1(int ram_size, int v
     }
 
     if (pci_enabled && acpi_enabled) {
+        int f;
+        uint8_t *d = MAP_FAILED;
         piix4_pm_init(pci_bus, piix3_devfn + 3);
+        snprintf(buf, sizeof(buf), "%s/%s", bios_dir, SMBUS_EEPROM_FILENAME);
+        f = open(buf, O_RDWR);
+        if (f >= 0) {
+            ftruncate(f, 8 * 256);
+            d = mmap(0, 8 * 256, PROT_READ | PROT_WRITE, MAP_SHARED, f, 0);
+        }
+        if (d == MAP_FAILED)
+            d = qemu_mallocz(8 * 256);
+        for (i = 0; i < 8; i++) {
+            SMBusDevice *eeprom = smbus_eeprom_device_init(0x50 + i,
+                d + (i * 256));
+            piix4_smbus_register_device(eeprom, 0x50 + i);
+        }
     }
 
 #if 0
Index: qemu-0.8.2/Makefile.target
===================================================================
--- qemu-0.8.2.orig/Makefile.target
+++ qemu-0.8.2/Makefile.target
@@ -338,7 +338,7 @@ ifeq ($(TARGET_BASE_ARCH), i386)
 VL_OBJS+= ide.o pckbd.o ps2.o vga.o $(SOUND_HW) dma.o $(AUDIODRV)
 VL_OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
 VL_OBJS+= cirrus_vga.o mixeng.o apic.o parallel.o acpi.o piix_pci.o
-VL_OBJS+= usb-uhci.o
+VL_OBJS+= usb-uhci.o smbus_eeprom.o
 DEFINES += -DHAS_AUDIO
 endif
 ifeq ($(TARGET_BASE_ARCH), ppc)