4 files changed, 893 insertions, 0 deletions

diff --git a/arch/x86/include/asm/intel_scu_ipc.h b/arch/x86/include/asm/intel_scu_ipc.h
new file mode 100644
index 000000000000..4470c9ad4a3e
--- /dev/null
+++ b/arch/x86/include/asm/intel_scu_ipc.h
@@ -0,0 +1,55 @@
+#ifndef _ASM_X86_INTEL_SCU_IPC_H_
+#define  _ASM_X86_INTEL_SCU_IPC_H_
+
+/* Read single register */
+int intel_scu_ipc_ioread8(u16 addr, u8 *data);
+
+/* Read two sequential registers */
+int intel_scu_ipc_ioread16(u16 addr, u16 *data);
+
+/* Read four sequential registers */
+int intel_scu_ipc_ioread32(u16 addr, u32 *data);
+
+/* Read a vector */
+int intel_scu_ipc_readv(u16 *addr, u8 *data, int len);
+
+/* Write single register */
+int intel_scu_ipc_iowrite8(u16 addr, u8 data);
+
+/* Write two sequential registers */
+int intel_scu_ipc_iowrite16(u16 addr, u16 data);
+
+/* Write four sequential registers */
+int intel_scu_ipc_iowrite32(u16 addr, u32 data);
+
+/* Write a vector */
+int intel_scu_ipc_writev(u16 *addr, u8 *data, int len);
+
+/* Update single register based on the mask */
+int intel_scu_ipc_update_register(u16 addr, u8 data, u8 mask);
+
+/*
+ * Indirect register read
+ * Can be used when SCCB(System Controller Configuration Block) register
+ * HRIM(Honor Restricted IPC Messages) is set (bit 23)
+ */
+int intel_scu_ipc_register_read(u32 addr, u32 *data);
+
+/*
+ * Indirect register write
+ * Can be used when SCCB(System Controller Configuration Block) register
+ * HRIM(Honor Restricted IPC Messages) is set (bit 23)
+ */
+int intel_scu_ipc_register_write(u32 addr, u32 data);
+
+/* Issue commands to the SCU with or without data */
+int intel_scu_ipc_simple_command(int cmd, int sub);
+int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
+                                                        u32 *out, int outlen);
+/* I2C control api */
+int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data);
+
+/* Update FW version */
+int intel_scu_ipc_fw_update(u8 *buffer, u32 length);
+
+#endif
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 6c3320d75055..619134151ca6 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -527,4 +527,12 @@ config ACPI_CMPC
           keys as input device, backlight device, tablet and accelerometer
           devices.
 
+config INTEL_SCU_IPC
+        bool "Intel SCU IPC Support"
+        depends on X86_MRST
+        default y
+        ---help---
+          IPC is used to bridge the communications between kernel and SCU on
+          some embedded Intel x86 platforms.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index a906490e3530..8770bfe71431 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_ACPI_ASUS)		+= asus_acpi.o
 obj-$(CONFIG_TOPSTAR_LAPTOP)    += topstar-laptop.o
 obj-$(CONFIG_ACPI_TOSHIBA)      += toshiba_acpi.o
 obj-$(CONFIG_TOSHIBA_BT_RFKILL) += toshiba_bluetooth.o
+obj-$(CONFIG_INTEL_SCU_IPC)     += intel_scu_ipc.o
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
new file mode 100644
index 000000000000..576c3ed92435
--- /dev/null
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -0,0 +1,829 @@
+/*
+ * intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
+ *
+ * (C) Copyright 2008-2010 Intel Corporation
+ * Author: Sreedhara DS (sreedhara.ds@intel.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ *
+ * SCU runing in ARC processor communicates with other entity running in IA
+ * core through IPC mechanism which in turn messaging between IA core ad SCU.
+ * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and
+ * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with
+ * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC)
+ * along with other APIs.
+ */
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/sysdev.h>
+#include <linux/pm.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <asm/setup.h>
+#include <asm/intel_scu_ipc.h>
+
+/* IPC defines the following message types */
+#define IPCMSG_WATCHDOG_TIMER 0xF8 /* Set Kernel Watchdog Threshold */
+#define IPCMSG_BATTERY        0xEF /* Coulomb Counter Accumulator */
+#define IPCMSG_FW_UPDATE      0xFE /* Firmware update */
+#define IPCMSG_PCNTRL         0xFF /* Power controller unit read/write */
+#define IPCMSG_FW_REVISION    0xF4 /* Get firmware revision */
+
+/* Command id associated with message IPCMSG_PCNTRL */
+#define IPC_CMD_PCNTRL_W      0 /* Register write */
+#define IPC_CMD_PCNTRL_R      1 /* Register read */
+#define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
+
+/* Miscelaneous Command ids */
+#define IPC_CMD_INDIRECT_RD   2 /* 32bit indirect read */
+#define IPC_CMD_INDIRECT_WR   5 /* 32bit indirect write */
+
+/*
+ * IPC register summary
+ *
+ * IPC register blocks are memory mapped at fixed address of 0xFF11C000
+ * To read or write information to the SCU, driver writes to IPC-1 memory
+ * mapped registers (base address 0xFF11C000). The following is the IPC
+ * mechanism
+ *
+ * 1. IA core cDMI interface claims this transaction and converts it to a
+ *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
+ *
+ * 2. South Complex cDMI block receives this message and writes it to
+ *    the IPC-1 register block, causing an interrupt to the SCU
+ *
+ * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
+ *    message handler is called within firmware.
+ */
+
+#define IPC_BASE_ADDR     0xFF11C000    /* IPC1 base register address */
+#define IPC_MAX_ADDR      0x100         /* Maximum IPC regisers */
+#define IPC_WWBUF_SIZE    16            /* IPC Write buffer Size */
+#define IPC_RWBUF_SIZE    16            /* IPC Read buffer Size */
+#define IPC_I2C_BASE      0xFF12B000    /* I2C control register base address */
+#define IPC_I2C_MAX_ADDR  0x10          /* Maximum I2C regisers */
+
+static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id);
+static void ipc_remove(struct pci_dev *pdev);
+
+struct intel_scu_ipc_dev {
+        struct pci_dev *pdev;
+        void __iomem *ipc_base;
+        void __iomem *i2c_base;
+};
+
+static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
+
+static int platform = 1;
+module_param(platform, int, 0);
+MODULE_PARM_DESC(platform, "1 for moorestown platform");
+
+
+
+
+/*
+ * IPC Read Buffer (Read Only):
+ * 16 byte buffer for receiving data from SCU, if IPC command
+ * processing results in response data
+ */
+#define IPC_READ_BUFFER         0x90
+
+#define IPC_I2C_CNTRL_ADDR      0
+#define I2C_DATA_ADDR           0x04
+
+static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
+
+/*
+ * Command Register (Write Only):
+ * A write to this register results in an interrupt to the SCU core processor
+ * Format:
+ * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
+ */
+static inline void ipc_command(u32 cmd) /* Send ipc command */
+{
+        writel(cmd, ipcdev.ipc_base);
+}
+
+/*
+ * IPC Write Buffer (Write Only):
+ * 16-byte buffer for sending data associated with IPC command to
+ * SCU. Size of the data is specified in the IPC_COMMAND_REG register
+ */
+static inline void ipc_data_writel(u32 data, u32 offset) /* Write ipc data */
+{
+        writel(data, ipcdev.ipc_base + 0x80 + offset);
+}
+
+/*
+ * IPC destination Pointer (Write Only):
+ * Use content as pointer for destination write
+ */
+static inline void ipc_write_dptr(u32 data) /* Write dptr data */
+{
+        writel(data, ipcdev.ipc_base + 0x0C);
+}
+
+/*
+ * IPC Source Pointer (Write Only):
+ * Use content as pointer for read location
+*/
+static inline void ipc_write_sptr(u32 data) /* Write dptr data */
+{
+        writel(data, ipcdev.ipc_base + 0x08);
+}
+
+/*
+ * Status Register (Read Only):
+ * Driver will read this register to get the ready/busy status of the IPC
+ * block and error status of the IPC command that was just processed by SCU
+ * Format:
+ * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
+ */
+
+static inline u8 ipc_read_status(void)
+{
+        return __raw_readl(ipcdev.ipc_base + 0x04);
+}
+
+static inline u8 ipc_data_readb(u32 offset) /* Read ipc byte data */
+{
+        return readb(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
+}
+
+static inline u8 ipc_data_readl(u32 offset) /* Read ipc u32 data */
+{
+        return readl(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
+}
+
+static inline int busy_loop(void) /* Wait till scu status is busy */
+{
+        u32 status = 0;
+        u32 loop_count = 0;
+
+        status = ipc_read_status();
+        while (status & 1) {
+                udelay(1); /* scu processing time is in few u secods */
+                status = ipc_read_status();
+                loop_count++;
+                /* break if scu doesn't reset busy bit after huge retry */
+                if (loop_count > 100000) {
+                        dev_err(&ipcdev.pdev->dev, "IPC timed out");
+                        return -ETIMEDOUT;
+                }
+        }
+        return (status >> 1) & 1;
+}
+
+/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
+static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
+{
+        int nc;
+        u32 offset = 0;
+        u32 err = 0;
+        u8 cbuf[IPC_WWBUF_SIZE] = { '\0' };
+        u32 *wbuf = (u32 *)&cbuf;
+
+        mutex_lock(&ipclock);
+        if (ipcdev.pdev == NULL) {
+                mutex_unlock(&ipclock);
+                return -ENODEV;
+        }
+
+        if (platform == 1) {
+                /* Entry is 4 bytes for read/write, 5 bytes for read modify */
+                for (nc = 0; nc < count; nc++) {
+                        cbuf[offset] = addr[nc];
+                        cbuf[offset + 1] = addr[nc] >> 8;
+                        if (id != IPC_CMD_PCNTRL_R)
+                                cbuf[offset + 2] = data[nc];
+                        if (id == IPC_CMD_PCNTRL_M) {
+                                cbuf[offset + 3] = data[nc + 1];
+                                offset += 1;
+                        }
+                        offset += 3;
+                }
+                for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
+                        ipc_data_writel(wbuf[nc], offset); /* Write wbuff */
+
+        } else {
+                for (nc = 0, offset = 0; nc < count; nc++, offset += 2)
+                        ipc_data_writel(addr[nc], offset); /* Write addresses */
+                if (id != IPC_CMD_PCNTRL_R) {
+                        for (nc = 0; nc < count; nc++, offset++)
+                                ipc_data_writel(data[nc], offset); /* Write data */
+                        if (id == IPC_CMD_PCNTRL_M)
+                                ipc_data_writel(data[nc + 1], offset); /* Mask value*/
+                }
+        }
+
+        if (id != IPC_CMD_PCNTRL_M)
+                ipc_command((count * 3) << 16 |  id << 12 | 0 << 8 | op);
+        else
+                ipc_command((count * 4) << 16 |  id << 12 | 0 << 8 | op);
+
+        err = busy_loop();
+
+        if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
+                /* Workaround: values are read as 0 without memcpy_fromio */
+                memcpy_fromio(cbuf, ipcdev.ipc_base + IPC_READ_BUFFER, 16);
+                if (platform == 1) {
+                        for (nc = 0, offset = 2; nc < count; nc++, offset += 3)
+                                data[nc] = ipc_data_readb(offset);
+                } else {
+                        for (nc = 0; nc < count; nc++)
+                                data[nc] = ipc_data_readb(nc);
+                }
+        }
+        mutex_unlock(&ipclock);
+        return err;
+}
+
+/**
+ *      intel_scu_ipc_ioread8           -       read a word via the SCU
+ *      @addr: register on SCU
+ *      @data: return pointer for read byte
+ *
+ *      Read a single register. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_ioread8(u16 addr, u8 *data)
+{
+        return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
+}
+EXPORT_SYMBOL(intel_scu_ipc_ioread8);
+
+/**
+ *      intel_scu_ipc_ioread16          -       read a word via the SCU
+ *      @addr: register on SCU
+ *      @data: return pointer for read word
+ *
+ *      Read a register pair. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_ioread16(u16 addr, u16 *data)
+{
+        u16 x[2] = {addr, addr + 1 };
+        return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
+}
+EXPORT_SYMBOL(intel_scu_ipc_ioread16);
+
+/**
+ *      intel_scu_ipc_ioread32          -       read a dword via the SCU
+ *      @addr: register on SCU
+ *      @data: return pointer for read dword
+ *
+ *      Read four registers. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_ioread32(u16 addr, u32 *data)
+{
+        u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
+        return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
+}
+EXPORT_SYMBOL(intel_scu_ipc_ioread32);
+
+/**
+ *      intel_scu_ipc_iowrite8          -       write a byte via the SCU
+ *      @addr: register on SCU
+ *      @data: byte to write
+ *
+ *      Write a single register. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_iowrite8(u16 addr, u8 data)
+{
+        return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
+}
+EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
+
+/**
+ *      intel_scu_ipc_iowrite16         -       write a word via the SCU
+ *      @addr: register on SCU
+ *      @data: word to write
+ *
+ *      Write two registers. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_iowrite16(u16 addr, u16 data)
+{
+        u16 x[2] = {addr, addr + 1 };
+        return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
+}
+EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
+
+/**
+ *      intel_scu_ipc_iowrite32         -       write a dword via the SCU
+ *      @addr: register on SCU
+ *      @data: dword to write
+ *
+ *      Write four registers. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_iowrite32(u16 addr, u32 data)
+{
+        u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
+        return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
+}
+EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
+
+/**
+ *      intel_scu_ipc_readvv            -       read a set of registers
+ *      @addr: register list
+ *      @data: bytes to return
+ *      @len: length of array
+ *
+ *      Read registers. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      The largest array length permitted by the hardware is 5 items.
+ *
+ *      This function may sleep.
+ */
+int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
+{
+        return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
+}
+EXPORT_SYMBOL(intel_scu_ipc_readv);
+
+/**
+ *      intel_scu_ipc_writev            -       write a set of registers
+ *      @addr: register list
+ *      @data: bytes to write
+ *      @len: length of array
+ *
+ *      Write registers. Returns 0 on success or an error code. All
+ *      locking between SCU accesses is handled for the caller.
+ *
+ *      The largest array length permitted by the hardware is 5 items.
+ *
+ *      This function may sleep.
+ *
+ */
+int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
+{
+        return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
+}
+EXPORT_SYMBOL(intel_scu_ipc_writev);
+
+
+/**
+ *      intel_scu_ipc_update_register   -       r/m/w a register
+ *      @addr: register address
+ *      @bits: bits to update
+ *      @mask: mask of bits to update
+ *
+ *      Read-modify-write power control unit register. The first data argument
+ *      must be register value and second is mask value
+ *      mask is a bitmap that indicates which bits to update.
+ *      0 = masked. Don't modify this bit, 1 = modify this bit.
+ *      returns 0 on success or an error code.
+ *
+ *      This function may sleep. Locking between SCU accesses is handled
+ *      for the caller.
+ */
+int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
+{
+        u8 data[2] = { bits, mask };
+        return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
+}
+EXPORT_SYMBOL(intel_scu_ipc_update_register);
+
+/**
+ *      intel_scu_ipc_register_read     -       32bit indirect read
+ *      @addr: register address
+ *      @value: 32bit value return
+ *
+ *      Performs IA 32 bit indirect read, returns 0 on success, or an
+ *      error code.
+ *
+ *      Can be used when SCCB(System Controller Configuration Block) register
+ *      HRIM(Honor Restricted IPC Messages) is set (bit 23)
+ *
+ *      This function may sleep. Locking for SCU accesses is handled for
+ *      the caller.
+ */
+int intel_scu_ipc_register_read(u32 addr, u32 *value)
+{
+        u32 err = 0;
+
+        mutex_lock(&ipclock);
+        if (ipcdev.pdev == NULL) {
+                mutex_unlock(&ipclock);
+                return -ENODEV;
+        }
+        ipc_write_sptr(addr);
+        ipc_command(4 << 16 | IPC_CMD_INDIRECT_RD);
+        err = busy_loop();
+        *value = ipc_data_readl(0);
+        mutex_unlock(&ipclock);
+        return err;
+}
+EXPORT_SYMBOL(intel_scu_ipc_register_read);
+
+/**
+ *      intel_scu_ipc_register_write    -       32bit indirect write
+ *      @addr: register address
+ *      @value: 32bit value to write
+ *
+ *      Performs IA 32 bit indirect write, returns 0 on success, or an
+ *      error code.
+ *
+ *      Can be used when SCCB(System Controller Configuration Block) register
+ *      HRIM(Honor Restricted IPC Messages) is set (bit 23)
+ *
+ *      This function may sleep. Locking for SCU accesses is handled for
+ *      the caller.
+ */
+int intel_scu_ipc_register_write(u32 addr, u32 value)
+{
+        u32 err = 0;
+
+        mutex_lock(&ipclock);
+        if (ipcdev.pdev == NULL) {
+                mutex_unlock(&ipclock);
+                return -ENODEV;
+        }
+        ipc_write_dptr(addr);
+        ipc_data_writel(value, 0);
+        ipc_command(4 << 16 | IPC_CMD_INDIRECT_WR);
+        err = busy_loop();
+        mutex_unlock(&ipclock);
+        return err;
+}
+EXPORT_SYMBOL(intel_scu_ipc_register_write);
+
+/**
+ *      intel_scu_ipc_simple_command    -       send a simple command
+ *      @cmd: command
+ *      @sub: sub type
+ *
+ *      Issue a simple command to the SCU. Do not use this interface if
+ *      you must then access data as any data values may be overwritten
+ *      by another SCU access by the time this function returns.
+ *
+ *      This function may sleep. Locking for SCU accesses is handled for
+ *      the caller.
+ */
+int intel_scu_ipc_simple_command(int cmd, int sub)
+{
+        u32 err = 0;
+
+        mutex_lock(&ipclock);
+        if (ipcdev.pdev == NULL) {
+                mutex_unlock(&ipclock);
+                return -ENODEV;
+        }
+        ipc_command(cmd << 12 | sub);
+        err = busy_loop();
+        mutex_unlock(&ipclock);
+        return err;
+}
+EXPORT_SYMBOL(intel_scu_ipc_simple_command);
+
+/**
+ *      intel_scu_ipc_command   -       command with data
+ *      @cmd: command
+ *      @sub: sub type
+ *      @in: input data
+ *      @inlen: input length
+ *      @out: output data
+ *      @outlein: output length
+ *
+ *      Issue a command to the SCU which involves data transfers. Do the
+ *      data copies under the lock but leave it for the caller to interpret
+ */
+
+int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
+                                                        u32 *out, int outlen)
+{
+        u32 err = 0;
+        int i = 0;
+
+        mutex_lock(&ipclock);
+        if (ipcdev.pdev == NULL) {
+                mutex_unlock(&ipclock);
+                return -ENODEV;
+        }
+
+        for (i = 0; i < inlen; i++)
+                ipc_data_writel(*in++, 4 * i);
+
+        ipc_command(cmd << 12 | sub);
+        err = busy_loop();
+
+        for (i = 0; i < outlen; i++)
+                *out++ = ipc_data_readl(4 * i);
+
+        mutex_unlock(&ipclock);
+        return err;
+}
+EXPORT_SYMBOL(intel_scu_ipc_command);
+
+/*I2C commands */
+#define IPC_I2C_WRITE 1 /* I2C Write command */
+#define IPC_I2C_READ  2 /* I2C Read command */
+
+/**
+ *      intel_scu_ipc_i2c_cntrl         -       I2C read/write operations
+ *      @addr: I2C address + command bits
+ *      @data: data to read/write
+ *
+ *      Perform an an I2C read/write operation via the SCU. All locking is
+ *      handled for the caller. This function may sleep.
+ *
+ *      Returns an error code or 0 on success.
+ *
+ *      This has to be in the IPC driver for the locking.
+ */
+int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
+{
+        u32 cmd = 0;
+
+        mutex_lock(&ipclock);
+        cmd = (addr >> 24) & 0xFF;
+        if (cmd == IPC_I2C_READ) {
+                writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
+                /* Write not getting updated without delay */
+                mdelay(1);
+                *data = readl(ipcdev.i2c_base + I2C_DATA_ADDR);
+        } else if (cmd == IPC_I2C_WRITE) {
+                writel(addr, ipcdev.i2c_base + I2C_DATA_ADDR);
+                mdelay(1);
+                writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
+        } else {
+                dev_err(&ipcdev.pdev->dev,
+                        "intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
+
+                mutex_unlock(&ipclock);
+                return -1;
+        }
+        mutex_unlock(&ipclock);
+        return 0;
+}
+EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
+
+#define IPC_FW_LOAD_ADDR 0xFFFC0000 /* Storage location for FW image */
+#define IPC_FW_UPDATE_MBOX_ADDR 0xFFFFDFF4 /* Mailbox between ipc and scu */
+#define IPC_MAX_FW_SIZE 262144 /* 256K storage size for loading the FW image */
+#define IPC_FW_MIP_HEADER_SIZE 2048 /* Firmware MIP header size */
+/* IPC inform SCU to get ready for update process */
+#define IPC_CMD_FW_UPDATE_READY  0x10FE
+/* IPC inform SCU to go for update process */
+#define IPC_CMD_FW_UPDATE_GO     0x20FE
+/* Status code for fw update */
+#define IPC_FW_UPDATE_SUCCESS   0x444f4e45 /* Status code 'DONE' */
+#define IPC_FW_UPDATE_BADN      0x4241444E /* Status code 'BADN' */
+#define IPC_FW_TXHIGH           0x54784849 /* Status code 'IPC_FW_TXHIGH' */
+#define IPC_FW_TXLOW            0x54784c4f /* Status code 'IPC_FW_TXLOW' */
+
+struct fw_update_mailbox {
+        u32    status;
+        u32    scu_flag;
+        u32    driver_flag;
+};
+
+
+/**
+ *      intel_scu_ipc_fw_update -        Firmware update utility
+ *      @buffer: firmware buffer
+ *      @length: size of firmware buffer
+ *
+ *      This function provides an interface to load the firmware into
+ *      the SCU. Returns 0 on success or -1 on failure
+ */
+int intel_scu_ipc_fw_update(u8 *buffer, u32 length)
+{
+        void __iomem *fw_update_base;
+        struct fw_update_mailbox __iomem *mailbox = NULL;
+        int retry_cnt = 0;
+        u32 status;
+
+        mutex_lock(&ipclock);
+        fw_update_base = ioremap_nocache(IPC_FW_LOAD_ADDR, (128*1024));
+        if (fw_update_base == NULL) {
+                mutex_unlock(&ipclock);
+                return -ENOMEM;
+        }
+        mailbox = ioremap_nocache(IPC_FW_UPDATE_MBOX_ADDR,
+                                        sizeof(struct fw_update_mailbox));
+        if (mailbox == NULL) {
+                iounmap(fw_update_base);
+                mutex_unlock(&ipclock);
+                return -ENOMEM;
+        }
+
+        ipc_command(IPC_CMD_FW_UPDATE_READY);
+
+        /* Intitialize mailbox */
+        writel(0, &mailbox->status);
+        writel(0, &mailbox->scu_flag);
+        writel(0, &mailbox->driver_flag);
+
+        /* Driver copies the 2KB MIP header to SRAM at 0xFFFC0000*/
+        memcpy_toio(fw_update_base, buffer, 0x800);
+
+        /* Driver sends "FW Update" IPC command (CMD_ID 0xFE; MSG_ID 0x02).
+        * Upon receiving this command, SCU will write the 2K MIP header
+        * from 0xFFFC0000 into NAND.
+        * SCU will write a status code into the Mailbox, and then set scu_flag.
+        */
+
+        ipc_command(IPC_CMD_FW_UPDATE_GO);
+
+        /*Driver stalls until scu_flag is set */
+        while (readl(&mailbox->scu_flag) != 1) {
+                rmb();
+                mdelay(1);
+        }
+
+        /* Driver checks Mailbox status.
+         * If the status is 'BADN', then abort (bad NAND).
+         * If the status is 'IPC_FW_TXLOW', then continue.
+         */
+        while (readl(&mailbox->status) != IPC_FW_TXLOW) {
+                rmb();
+                mdelay(10);
+        }
+        mdelay(10);
+
+update_retry:
+        if (retry_cnt > 5)
+                goto update_end;
+
+        if (readl(&mailbox->status) != IPC_FW_TXLOW)
+                goto update_end;
+        buffer = buffer + 0x800;
+        memcpy_toio(fw_update_base, buffer, 0x20000);
+        writel(1, &mailbox->driver_flag);
+        while (readl(&mailbox->scu_flag) == 1) {
+                rmb();
+                mdelay(1);
+        }
+
+        /* check for 'BADN' */
+        if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
+                goto update_end;
+
+        while (readl(&mailbox->status) != IPC_FW_TXHIGH) {
+                rmb();
+                mdelay(10);
+        }
+        mdelay(10);
+
+        if (readl(&mailbox->status) != IPC_FW_TXHIGH)
+                goto update_end;
+
+        buffer = buffer + 0x20000;
+        memcpy_toio(fw_update_base, buffer, 0x20000);
+        writel(0, &mailbox->driver_flag);
+
+        while (mailbox->scu_flag == 0) {
+                rmb();
+                mdelay(1);
+        }
+
+        /* check for 'BADN' */
+        if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
+                goto update_end;
+
+        if (readl(&mailbox->status) == IPC_FW_TXLOW) {
+                ++retry_cnt;
+                goto update_retry;
+        }
+
+update_end:
+        status = readl(&mailbox->status);
+
+        iounmap(fw_update_base);
+        iounmap(mailbox);
+        mutex_unlock(&ipclock);
+
+        if (status == IPC_FW_UPDATE_SUCCESS)
+                return 0;
+        return -1;
+}
+EXPORT_SYMBOL(intel_scu_ipc_fw_update);
+
+/*
+ * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
+ * When ioc bit is set to 1, caller api must wait for interrupt handler called
+ * which in turn unlocks the caller api. Currently this is not used
+ *
+ * This is edge triggered so we need take no action to clear anything
+ */
+static irqreturn_t ioc(int irq, void *dev_id)
+{
+        return IRQ_HANDLED;
+}
+
+/**
+ *      ipc_probe       -       probe an Intel SCU IPC
+ *      @dev: the PCI device matching
+ *      @id: entry in the match table
+ *
+ *      Enable and install an intel SCU IPC. This appears in the PCI space
+ *      but uses some hard coded addresses as well.
+ */
+static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+        int err;
+        resource_size_t pci_resource;
+
+        if (ipcdev.pdev)                /* We support only one SCU */
+                return -EBUSY;
+
+        ipcdev.pdev = pci_dev_get(dev);
+
+        err = pci_enable_device(dev);
+        if (err)
+                return err;
+
+        err = pci_request_regions(dev, "intel_scu_ipc");
+        if (err)
+                return err;
+
+        pci_resource = pci_resource_start(dev, 0);
+        if (!pci_resource)
+                return -ENOMEM;
+
+        if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
+                return -EBUSY;
+
+        ipcdev.ipc_base = ioremap_nocache(IPC_BASE_ADDR, IPC_MAX_ADDR);
+        if (!ipcdev.ipc_base)
+                return -ENOMEM;
+
+        ipcdev.i2c_base = ioremap_nocache(IPC_I2C_BASE, IPC_I2C_MAX_ADDR);
+        if (!ipcdev.i2c_base) {
+                iounmap(ipcdev.ipc_base);
+                return -ENOMEM;
+        }
+        return 0;
+}
+
+/**
+ *      ipc_remove      -       remove a bound IPC device
+ *      @pdev: PCI device
+ *
+ *      In practice the SCU is not removable but this function is also
+ *      called for each device on a module unload or cleanup which is the
+ *      path that will get used.
+ *
+ *      Free up the mappings and release the PCI resources
+ */
+static void ipc_remove(struct pci_dev *pdev)
+{
+        free_irq(pdev->irq, &ipcdev);
+        pci_release_regions(pdev);
+        pci_dev_put(ipcdev.pdev);
+        iounmap(ipcdev.ipc_base);
+        iounmap(ipcdev.i2c_base);
+        ipcdev.pdev = NULL;
+}
+
+static const struct pci_device_id pci_ids[] = {
+        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080e)},
+        { 0,}
+};
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+static struct pci_driver ipc_driver = {
+        .name = "intel_scu_ipc",
+        .id_table = pci_ids,
+        .probe = ipc_probe,
+        .remove = ipc_remove,
+};
+
+
+static int __init intel_scu_ipc_init(void)
+{
+        return  pci_register_driver(&ipc_driver);
+}
+
+static void __exit intel_scu_ipc_exit(void)
+{
+        pci_unregister_driver(&ipc_driver);
+}
+
+MODULE_AUTHOR("Sreedhara DS <sreedhara.ds@intel.com>");
+MODULE_DESCRIPTION("Intel SCU IPC driver");
+MODULE_LICENSE("GPL");
+
+module_init(intel_scu_ipc_init);
+module_exit(intel_scu_ipc_exit);