/*
* 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 running 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/device.h>
#include <linux/pm.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/sfi.h>
#include <linux/module.h>
#include <asm/intel-mid.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 */
/*
* 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 20 /* IPC Write buffer Size */
#define IPC_RWBUF_SIZE 20 /* 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; /* Platform type */
/*
* 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);
}
/*
* 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 u32 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;
}
}
if ((status >> 1) & 1)
return -EIO;
return 0;
}
/* 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;
int err;
u8 cbuf[IPC_WWBUF_SIZE] = { };
u32 *wbuf = (u32 *)&cbuf;
mutex_lock(&ipclock);
memset(cbuf, 0, sizeof(cbuf));
if (ipcdev.pdev == NULL) {
mutex_unlock(&ipclock);
return -ENODEV;
}
for (nc = 0; nc < count; nc++, offset += 2) {
cbuf[offset] = addr[nc];
cbuf[offset + 1] = addr[nc] >> 8;
}
if (id == IPC_CMD_PCNTRL_R) {
for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
ipc_data_writel(wbuf[nc], offset);
ipc_command((count*2) << 16 | id << 12 | 0 << 8 | op);
} else if (id == IPC_CMD_PCNTRL_W) {
for (nc = 0; nc < count; nc++, offset += 1)
cbuf[offset] = data[nc];
for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
ipc_data_writel(wbuf[nc], offset);
ipc_command((count*3) << 16 | id << 12 | 0 << 8 | op);
} else if (id == IPC_CMD_PCNTRL_M) {
cbuf[offset] = data[0];
cbuf[offset + 1] = data[1];
ipc_data_writel(wbuf[0], 0); /* Write wbuff */
ipc_command(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 + 0x90, 16);
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_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)
{
int err;
mutex_lock(&ipclock);
if (ipcdev.pdev == NULL) {
mutex_unlock(&ipclock);
return -ENODEV;
}
ipc_command(sub << 12 | cmd);
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 in dwords
* @out: output data
* @outlein: output length in dwords
*
* 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)
{
int i, err;
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((inlen << 16) | (sub << 12) | cmd);
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);
if (ipcdev.pdev == NULL) {
mutex_unlock(&ipclock);
return -ENODEV;
}
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(*data, 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 -EIO;
}
mutex_unlock(&ipclock);
return 0;
}
EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
/*
* 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;
}
intel_scu_devices_create();
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;
intel_scu_devices_destroy();
}
static DEFINE_PCI_DEVICE_TABLE(pci_ids) = {
{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x082a)},
{ 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)
{
platform = intel_mid_identify_cpu();
if (platform == 0)
return -ENODEV;
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);
