/*
* PowerMac G5 SMU driver
*
* Copyright 2004 J. Mayer <l_indien@magic.fr>
* Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
*
* Released under the term of the GNU GPL v2.
*/
/*
* TODO:
* - maybe add timeout to commands ?
* - blocking version of time functions
* - polling version of i2c commands (including timer that works with
* interrutps off)
* - maybe avoid some data copies with i2c by directly using the smu cmd
* buffer and a lower level internal interface
* - understand SMU -> CPU events and implement reception of them via
* the userland interface
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/dmapool.h>
#include <linux/bootmem.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/completion.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/sysdev.h>
#include <linux/poll.h>
#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/smu.h>
#include <asm/sections.h>
#include <asm/abs_addr.h>
#include <asm/uaccess.h>
#include <asm/of_device.h>
#define VERSION "0.6"
#define AUTHOR "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
#undef DEBUG_SMU
#ifdef DEBUG_SMU
#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
#else
#define DPRINTK(fmt, args...) do { } while (0)
#endif
/*
* This is the command buffer passed to the SMU hardware
*/
#define SMU_MAX_DATA 254
struct smu_cmd_buf {
u8 cmd;
u8 length;
u8 data[SMU_MAX_DATA];
};
struct smu_device {
spinlock_t lock;
struct device_node *of_node;
struct of_device *of_dev;
int doorbell; /* doorbell gpio */
u32 __iomem *db_buf; /* doorbell buffer */
int db_irq;
int msg;
int msg_irq;
struct smu_cmd_buf *cmd_buf; /* command buffer virtual */
u32 cmd_buf_abs; /* command buffer absolute */
struct list_head cmd_list;
struct smu_cmd *cmd_cur; /* pending command */
struct list_head cmd_i2c_list;
struct smu_i2c_cmd *cmd_i2c_cur; /* pending i2c command */
struct timer_list i2c_timer;
};
/*
* I don't think there will ever be more than one SMU, so
* for now, just hard code that
*/
static struct smu_device *smu;
/*
* SMU driver low level stuff
*/
static void smu_start_cmd(void)
{
unsigned long faddr, fend;
struct smu_cmd *cmd;
if (list_empty(&smu->cmd_list))
return;
/* Fetch first command in queue */
cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
smu->cmd_cur = cmd;
list_del(&cmd->link);
DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
cmd->data_len);
DPRINTK("SMU: data buffer: %02x %02x %02x %02x ...\n",
((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3]);
/* Fill the SMU command buffer */
smu->cmd_buf->cmd = cmd->cmd;
smu->cmd_buf->length = cmd->data_len;
memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
/* Flush command and data to RAM */
faddr = (unsigned long)smu->cmd_buf;
fend = faddr + smu->cmd_buf->length + 2;
flush_inval_dcache_range(faddr, fend);
/* This isn't exactly a DMA mapping here, I suspect
* the SMU is actually communicating with us via i2c to the
* northbridge or the CPU to access RAM.
*/
writel(smu->cmd_buf_abs, smu->db_buf);
/* Ring the SMU doorbell */
pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
}
static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
{
unsigned long flags;
struct smu_cmd *cmd;
void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
void *misc = NULL;
u8 gpio;
int rc = 0;
/* SMU completed the command, well, we hope, let's make sure
* of it
*/
spin_lock_irqsave(&smu->lock, flags);
gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
if ((gpio & 7) != 7) {
spin_unlock_irqrestore(&smu->lock, flags);
return IRQ_HANDLED;
}
cmd = smu->cmd_cur;
smu->cmd_cur = NULL;
if (cmd == NULL)
goto bail;
if (rc == 0) {
unsigned long faddr;
int reply_len;
u8 ack;
/* CPU might have brought back the cache line, so we need
* to flush again before peeking at the SMU response. We
* flush the entire buffer for now as we haven't read the
* reply lenght (it's only 2 cache lines anyway)
*/
faddr = (unsigned long)smu->cmd_buf;
flush_inval_dcache_range(faddr, faddr + 256);
/* Now check ack */
ack = (~cmd->cmd) & 0xff;
if (ack != smu->cmd_buf->cmd) {
DPRINTK("SMU: incorrect ack, want %x got %x\n",
ack, smu->cmd_buf->cmd);
rc = -EIO;
}
reply_len = rc == 0 ? smu->cmd_buf->length : 0;
DPRINTK("SMU: reply len: %d\n", reply_len);
if (reply_len > cmd->reply_len) {
printk(KERN_WARNING "SMU: reply buffer too small,"
"got %d bytes for a %d bytes buffer\n",
reply_len, cmd->reply_len);
reply_len = cmd->reply_len;
}
cmd->reply_len = reply_len;
if (cmd->reply_buf && reply_len)
memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
}
/* Now complete the command. Write status last in order as we lost
* ownership of the command structure as soon as it's no longer -1
*/
done = cmd->done;
misc = cmd->misc;
mb();
cmd->status = rc;
bail:
/* Start next command if any */
smu_start_cmd();
spin_unlock_irqrestore(&smu->lock, flags);
/* Call command completion handler if any */
if (done)
done(cmd, misc);
/* It's an edge interrupt, nothing to do */
return IRQ_HANDLED;
}
static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
{
/* I don't quite know what to do with this one, we seem to never
* receive it, so I suspect we have to arm it someway in the SMU
* to start getting events that way.
*/
printk(KERN_INFO "SMU: message interrupt !\n");
/* It's an edge interrupt, nothing to do */
return IRQ_HANDLED;
}
/*
* Queued command management.
*
*/
int smu_queue_cmd(struct smu_cmd *cmd)
{
unsigned long flags;
if (smu == NULL)
return -ENODEV;
if (cmd->data_len > SMU_MAX_DATA ||
cmd->reply_len > SMU_MAX_DATA)
return -EINVAL;
cmd->status = 1;
spin_lock_irqsave(&smu->lock, flags);
list_add_tail(&cmd->link, &smu->cmd_list);
if (smu->cmd_cur == NULL)
smu_start_cmd();
spin_unlock_irqrestore(&smu->lock, flags);
return 0;
}
EXPORT_SYMBOL(smu_queue_cmd);
int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
unsigned int data_len,
void (*done)(struct smu_cmd *cmd, void *misc),
void *misc, ...)
{
struct smu_cmd *cmd = &scmd->cmd;
va_list list;
int i;
if (data_len > sizeof(scmd->buffer))
return -EINVAL;
memset(scmd, 0, sizeof(*scmd));
cmd->cmd = command;
cmd->data_len = data_len;
cmd->data_buf = scmd->buffer;
cmd->reply_len = sizeof(scmd->buffer);
cmd->reply_buf = scmd->buffer;
cmd->done = done;
cmd->misc = misc;
va_start(list, misc);
for (i = 0; i < data_len; ++i)
scmd->buffer[i] = (u8)va_arg(list, int);
va_end(list);
return smu_queue_cmd(cmd);
}
EXPORT_SYMBOL(smu_queue_simple);
void smu_poll(void)
{
u8 gpio;
if (smu == NULL)
return;
gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
if ((gpio & 7) == 7)
smu_db_intr(smu->db_irq, smu, NULL);
}
EXPORT_SYMBOL(smu_poll);
void smu_done_complete(struct smu_cmd *cmd, void *misc)
{
struct completion *comp = misc;
complete(comp);
}
EXPORT_SYMBOL(smu_done_complete);
void smu_spinwait_cmd(struct smu_cmd *cmd)
{
while(cmd->status == 1)
smu_poll();
}
EXPORT_SYMBOL(smu_spinwait_cmd);
/* RTC low level commands */
static inline int bcd2hex (int n)
{
return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
}
static inline int hex2bcd (int n)
{
return ((n / 10) << 4) + (n % 10);
}
static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
struct rtc_time *time)
{
cmd_buf->cmd = 0x8e;
cmd_buf->length = 8;
cmd_buf->data[0] = 0x80;
cmd_buf->data[1] = hex2bcd(time->tm_sec);
cmd_buf->data[2] = hex2bcd(time->tm_min);
cmd_buf->data[3] = hex2bcd(time->tm_hour);
cmd_buf->data[4] = time->tm_wday;
cmd_buf->data[5] = hex2bcd(time->tm_mday);
cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
}
int smu_get_rtc_time(struct rtc_time *time, int spinwait)
{
struct smu_simple_cmd cmd;
int rc;
if (smu == NULL)
return -ENODEV;
memset(time, 0, sizeof(struct rtc_time));
rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
SMU_CMD_RTC_GET_DATETIME);
if (rc)
return rc;
smu_spinwait_simple(&cmd);
time->tm_sec = bcd2hex(cmd.buffer[0]);
time->tm_min = bcd2hex(cmd.buffer[1]);
time->tm_hour = bcd2hex(cmd.buffer[2]);
time->tm_wday = bcd2hex(cmd.buffer[3]);
time->tm_mday = bcd2hex(cmd.buffer[4]);
time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
return 0;
}
int smu_set_rtc_time(struct rtc_time *time, int spinwait)
{
struct smu_simple_cmd cmd;
int rc;
if (smu == NULL)
return -ENODEV;
rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
SMU_CMD_RTC_SET_DATETIME,
hex2bcd(time->tm_sec),
hex2bcd(time->tm_min),
hex2bcd(time->tm_hour),
time->tm_wday,
hex2bcd(time->tm_mday),
hex2bcd(time->tm_mon) + 1,
hex2bcd(time->tm_year - 100));
if (rc)
return rc;
smu_spinwait_simple(&cmd);
return 0;
}
void smu_shutdown(void)
{
struct smu_simple_cmd cmd;
if (smu == NULL)
return;
if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
return;
smu_spinwait_simple(&cmd);
for (;;)
;
}
void smu_restart(void)
{
struct smu_simple_cmd cmd;
if (smu == NULL)
return;
if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
return;
smu_spinwait_simple(&cmd);
for (;;)
;
}
int smu_present(void)
{
return smu != NULL;
}
EXPORT_SYMBOL(smu_present);
int smu_init (void)
{
struct device_node *np;
u32 *data;
np = of_find_node_by_type(NULL, "smu");
if (np == NULL)
return -ENODEV;
printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
if (smu_cmdbuf_abs == 0) {
printk(KERN_ERR "SMU: Command buffer not allocated !\n");
return -EINVAL;
}
smu = alloc_bootmem(sizeof(struct smu_device));
if (smu == NULL)
return -ENOMEM;
memset(smu, 0, sizeof(*smu));
spin_lock_init(&smu->lock);
INIT_LIST_HEAD(&smu->cmd_list);
INIT_LIST_HEAD(&smu->cmd_i2c_list);
smu->of_node = np;
smu->db_irq = NO_IRQ;
smu->msg_irq = NO_IRQ;
init_timer(&smu->i2c_timer);
/* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
* 32 bits value safely
*/
smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
np = of_find_node_by_name(NULL, "smu-doorbell");
if (np == NULL) {
printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
goto fail;
}
data = (u32 *)get_property(np, "reg", NULL);
if (data == NULL) {
of_node_put(np);
printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
goto fail;
}
/* Current setup has one doorbell GPIO that does both doorbell
* and ack. GPIOs are at 0x50, best would be to find that out
* in the device-tree though.
*/
smu->doorbell = *data;
if (smu->doorbell < 0x50)
smu->doorbell += 0x50;
if (np->n_intrs > 0)
smu->db_irq = np->intrs[0].line;
of_node_put(np);
/* Now look for the smu-interrupt GPIO */
do {
np = of_find_node_by_name(NULL, "smu-interrupt");
if (np == NULL)
break;
data = (u32 *)get_property(np, "reg", NULL);
if (data == NULL) {
of_node_put(np);
break;
}
smu->msg = *data;
if (smu->msg < 0x50)
smu->msg += 0x50;
if (np->n_intrs > 0)
smu->msg_irq = np->intrs[0].line;
of_node_put(np);
} while(0);
/* Doorbell buffer is currently hard-coded, I didn't find a proper
* device-tree entry giving the address. Best would probably to use
* an offset for K2 base though, but let's do it that way for now.
*/
smu->db_buf = ioremap(0x8000860c, 0x1000);
if (smu->db_buf == NULL) {
printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
goto fail;
}
sys_ctrler = SYS_CTRLER_SMU;
return 0;
fail:
smu = NULL;
return -ENXIO;
}
static int smu_late_init(void)
{
if (!smu)
return 0;
/*
* Try to request the interrupts
*/
if (smu->db_irq != NO_IRQ) {
if (request_irq(smu->db_irq, smu_db_intr,
SA_SHIRQ, "SMU doorbell", smu) < 0) {
printk(KERN_WARNING "SMU: can't "
"request interrupt %d\n",
smu->db_irq);
smu->db_irq = NO_IRQ;
}
}
if (smu->msg_irq != NO_IRQ) {
if (request_irq(smu->msg_irq, smu_msg_intr,
SA_SHIRQ, "SMU message", smu) < 0) {
printk(KERN_WARNING "SMU: can't "
"request interrupt %d\n",
smu->msg_irq);
smu->msg_irq = NO_IRQ;
}
}
return 0;
}
arch_initcall(smu_late_init);
/*
* sysfs visibility
*/
static void smu_expose_childs(void *unused)
{
struct device_node *np;
for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
if (device_is_compatible(np, "smu-i2c")) {
char name[32];
u32 *reg = (u32 *)get_property(np, "reg", NULL);
if (reg == NULL)
continue;
sprintf(name, "smu-i2c-%02x", *reg);
of_platform_device_create(np, name, &smu->of_dev->dev);
}
}
}
static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
static int smu_platform_probe(struct of_device* dev,
const struct of_device_id *match)
{
if (!smu)
return -ENODEV;
smu->of_dev = dev;
/*
* Ok, we are matched, now expose all i2c busses. We have to defer
* that unfortunately or it would deadlock inside the device model
*/
schedule_work(&smu_expose_childs_work);
return 0;
}
static struct of_device_id smu_platform_match[] =
{
{
.type = "smu",
},
{},
};
static struct of_platform_driver smu_of_platform_driver =
{
.name = "smu",
.match_table = smu_platform_match,
.probe = smu_platform_probe,
};
static int __init smu_init_sysfs(void)
{
int rc;
/*
* Due to sysfs bogosity, a sysdev is not a real device, so
* we should in fact create both if we want sysdev semantics
* for power management.
* For now, we don't power manage machines with an SMU chip,
* I'm a bit too far from figuring out how that works with those
* new chipsets, but that will come back and bite us
*/
rc = of_register_driver(&smu_of_platform_driver);
return 0;
}
device_initcall(smu_init_sysfs);
struct of_device *smu_get_ofdev(void)
{
if (!smu)
return NULL;
return smu->of_dev;
}
EXPORT_SYMBOL_GPL(smu_get_ofdev);
/*
* i2c interface
*/
static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
{
void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
void *misc = cmd->misc;
unsigned long flags;
/* Check for read case */
if (!fail && cmd->read) {
if (cmd->pdata[0] < 1)
fail = 1;
else
memcpy(cmd->info.data, &cmd->pdata[1],
cmd->info.datalen);
}
DPRINTK("SMU: completing, success: %d\n", !fail);
/* Update status and mark no pending i2c command with lock
* held so nobody comes in while we dequeue an eventual
* pending next i2c command
*/
spin_lock_irqsave(&smu->lock, flags);
smu->cmd_i2c_cur = NULL;
wmb();
cmd->status = fail ? -EIO : 0;
/* Is there another i2c command waiting ? */
if (!list_empty(&smu->cmd_i2c_list)) {
struct smu_i2c_cmd *newcmd;
/* Fetch it, new current, remove from list */
newcmd = list_entry(smu->cmd_i2c_list.next,
struct smu_i2c_cmd, link);
smu->cmd_i2c_cur = newcmd;
list_del(&cmd->link);
/* Queue with low level smu */
list_add_tail(&cmd->scmd.link, &smu->cmd_list);
if (smu->cmd_cur == NULL)
smu_start_cmd();
}
spin_unlock_irqrestore(&smu->lock, flags);
/* Call command completion handler if any */
if (done)
done(cmd, misc);
}
static void smu_i2c_retry(unsigned long data)
{
struct smu_i2c_cmd *cmd = (struct smu_i2c_cmd *)data;
DPRINTK("SMU: i2c failure, requeuing...\n");
/* requeue command simply by resetting reply_len */
cmd->pdata[0] = 0xff;
cmd->scmd.reply_len = 0x10;
smu_queue_cmd(&cmd->scmd);
}
static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
{
struct smu_i2c_cmd *cmd = misc;
int fail = 0;
DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
/* Check for possible status */
if (scmd->status < 0)
fail = 1;
else if (cmd->read) {
if (cmd->stage == 0)
fail = cmd->pdata[0] != 0;
else
fail = cmd->pdata[0] >= 0x80;
} else {
fail = cmd->pdata[0] != 0;
}
/* Handle failures by requeuing command, after 5ms interval
*/
if (fail && --cmd->retries > 0) {
DPRINTK("SMU: i2c failure, starting timer...\n");
smu->i2c_timer.function = smu_i2c_retry;
smu->i2c_timer.data = (unsigned long)cmd;
smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
add_timer(&smu->i2c_timer);
return;
}
/* If failure or stage 1, command is complete */
if (fail || cmd->stage != 0) {
smu_i2c_complete_command(cmd, fail);
return;
}
DPRINTK("SMU: going to stage 1\n");
/* Ok, initial command complete, now poll status */
scmd->reply_buf = cmd->pdata;
scmd->reply_len = 0x10;
scmd->data_buf = cmd->pdata;
scmd->data_len = 1;
cmd->pdata[0] = 0;
cmd->stage = 1;
cmd->retries = 20;
smu_queue_cmd(scmd);
}
int smu_queue_i2c(struct smu_i2c_cmd *cmd)
{
unsigned long flags;
if (smu == NULL)
return -ENODEV;
/* Fill most fields of scmd */
cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
cmd->scmd.done = smu_i2c_low_completion;
cmd->scmd.misc = cmd;
cmd->scmd.reply_buf = cmd->pdata;
cmd->scmd.reply_len = 0x10;
cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
cmd->scmd.status = 1;
cmd->stage = 0;
cmd->pdata[0] = 0xff;
cmd->retries = 20;
cmd->status = 1;
/* Check transfer type, sanitize some "info" fields
* based on transfer type and do more checking
*/
cmd->info.caddr = cmd->info.devaddr;
cmd->read = cmd->info.devaddr & 0x01;
switch(cmd->info.type) {
case SMU_I2C_TRANSFER_SIMPLE:
memset(&cmd->info.sublen, 0, 4);
break;
case SMU_I2C_TRANSFER_COMBINED:
cmd->info.devaddr &= 0xfe;
case SMU_I2C_TRANSFER_STDSUB:
if (cmd->info.sublen > 3)
return -EINVAL;
break;
default:
return -EINVAL;
}
/* Finish setting up command based on transfer direction
*/
if (cmd->read) {
if (cmd->info.datalen > SMU_I2C_READ_MAX)
return -EINVAL;
memset(cmd->info.data, 0xff, cmd->info.datalen);
cmd->scmd.data_len = 9;
} else {
if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
return -EINVAL;
cmd->scmd.data_len = 9 + cmd->info.datalen;
}
DPRINTK("SMU: i2c enqueuing command\n");
DPRINTK("SMU: %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
cmd->read ? "read" : "write", cmd->info.datalen,
cmd->info.bus, cmd->info.caddr,
cmd->info.subaddr[0], cmd->info.type);
/* Enqueue command in i2c list, and if empty, enqueue also in
* main command list
*/
spin_lock_irqsave(&smu->lock, flags);
if (smu->cmd_i2c_cur == NULL) {
smu->cmd_i2c_cur = cmd;
list_add_tail(&cmd->scmd.link, &smu->cmd_list);
if (smu->cmd_cur == NULL)
smu_start_cmd();
} else
list_add_tail(&cmd->link, &smu->cmd_i2c_list);
spin_unlock_irqrestore(&smu->lock, flags);
return 0;
}
/*
* Userland driver interface
*/
static LIST_HEAD(smu_clist);
static DEFINE_SPINLOCK(smu_clist_lock);
enum smu_file_mode {
smu_file_commands,
smu_file_events,
smu_file_closing
};
struct smu_private
{
struct list_head list;
enum smu_file_mode mode;
int busy;
struct smu_cmd cmd;
spinlock_t lock;
wait_queue_head_t wait;
u8 buffer[SMU_MAX_DATA];
};
static int smu_open(struct inode *inode, struct file *file)
{
struct smu_private *pp;
unsigned long flags;
pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
if (pp == 0)
return -ENOMEM;
memset(pp, 0, sizeof(struct smu_private));
spin_lock_init(&pp->lock);
pp->mode = smu_file_commands;
init_waitqueue_head(&pp->wait);
spin_lock_irqsave(&smu_clist_lock, flags);
list_add(&pp->list, &smu_clist);
spin_unlock_irqrestore(&smu_clist_lock, flags);
file->private_data = pp;
return 0;
}
static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
{
struct smu_private *pp = misc;
wake_up_all(&pp->wait);
}
static ssize_t smu_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct smu_private *pp = file->private_data;
unsigned long flags;
struct smu_user_cmd_hdr hdr;
int rc = 0;
if (pp->busy)
return -EBUSY;
else if (copy_from_user(&hdr, buf, sizeof(hdr)))
return -EFAULT;
else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
pp->mode = smu_file_events;
return 0;
} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
return -EINVAL;
else if (pp->mode != smu_file_commands)
return -EBADFD;
else if (hdr.data_len > SMU_MAX_DATA)
return -EINVAL;
spin_lock_irqsave(&pp->lock, flags);
if (pp->busy) {
spin_unlock_irqrestore(&pp->lock, flags);
return -EBUSY;
}
pp->busy = 1;
pp->cmd.status = 1;
spin_unlock_irqrestore(&pp->lock, flags);
if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
pp->busy = 0;
return -EFAULT;
}
pp->cmd.cmd = hdr.cmd;
pp->cmd.data_len = hdr.data_len;
pp->cmd.reply_len = SMU_MAX_DATA;
pp->cmd.data_buf = pp->buffer;
pp->cmd.reply_buf = pp->buffer;
pp->cmd.done = smu_user_cmd_done;
pp->cmd.misc = pp;
rc = smu_queue_cmd(&pp->cmd);
if (rc < 0)
return rc;
return count;
}
static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
char __user *buf, size_t count)
{
DECLARE_WAITQUEUE(wait, current);
struct smu_user_reply_hdr hdr;
unsigned long flags;
int size, rc = 0;
if (!pp->busy)
return 0;
if (count < sizeof(struct smu_user_reply_hdr))
return -EOVERFLOW;
spin_lock_irqsave(&pp->lock, flags);
if (pp->cmd.status == 1) {
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
add_wait_queue(&pp->wait, &wait);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
rc = 0;
if (pp->cmd.status != 1)
break;
rc = -ERESTARTSYS;
if (signal_pending(current))
break;
spin_unlock_irqrestore(&pp->lock, flags);
schedule();
spin_lock_irqsave(&pp->lock, flags);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&pp->wait, &wait);
}
spin_unlock_irqrestore(&pp->lock, flags);
if (rc)
return rc;
if (pp->cmd.status != 0)
pp->cmd.reply_len = 0;
size = sizeof(hdr) + pp->cmd.reply_len;
if (count < size)
size = count;
rc = size;
hdr.status = pp->cmd.status;
hdr.reply_len = pp->cmd.reply_len;
if (copy_to_user(buf, &hdr, sizeof(hdr)))
return -EFAULT;
size -= sizeof(hdr);
if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
return -EFAULT;
pp->busy = 0;
return rc;
}
static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
char __user *buf, size_t count)
{
/* Not implemented */
msleep_interruptible(1000);
return 0;
}
static ssize_t smu_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct smu_private *pp = file->private_data;
if (pp->mode == smu_file_commands)
return smu_read_command(file, pp, buf, count);
if (pp->mode == smu_file_events)
return smu_read_events(file, pp, buf, count);
return -EBADFD;
}
static unsigned int smu_fpoll(struct file *file, poll_table *wait)
{
struct smu_private *pp = file->private_data;
unsigned int mask = 0;
unsigned long flags;
if (pp == 0)
return 0;
if (pp->mode == smu_file_commands) {
poll_wait(file, &pp->wait, wait);
spin_lock_irqsave(&pp->lock, flags);
if (pp->busy && pp->cmd.status != 1)
mask |= POLLIN;
spin_unlock_irqrestore(&pp->lock, flags);
} if (pp->mode == smu_file_events) {
/* Not yet implemented */
}
return mask;
}
static int smu_release(struct inode *inode, struct file *file)
{
struct smu_private *pp = file->private_data;
unsigned long flags;
unsigned int busy;
if (pp == 0)
return 0;
file->private_data = NULL;
/* Mark file as closing to avoid races with new request */
spin_lock_irqsave(&pp->lock, flags);
pp->mode = smu_file_closing;
busy = pp->busy;
/* Wait for any pending request to complete */
if (busy && pp->cmd.status == 1) {
DECLARE_WAITQUEUE(wait, current);
add_wait_queue(&pp->wait, &wait);
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (pp->cmd.status != 1)
break;
spin_lock_irqsave(&pp->lock, flags);
schedule();
spin_unlock_irqrestore(&pp->lock, flags);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&pp->wait, &wait);
}
spin_unlock_irqrestore(&pp->lock, flags);
spin_lock_irqsave(&smu_clist_lock, flags);
list_del(&pp->list);
spin_unlock_irqrestore(&smu_clist_lock, flags);
kfree(pp);
return 0;
}
static struct file_operations smu_device_fops = {
.llseek = no_llseek,
.read = smu_read,
.write = smu_write,
.poll = smu_fpoll,
.open = smu_open,
.release = smu_release,
};
static struct miscdevice pmu_device = {
MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
};
static int smu_device_init(void)
{
if (!smu)
return -ENODEV;
if (misc_register(&pmu_device) < 0)
printk(KERN_ERR "via-pmu: cannot register misc device.\n");
return 0;
}
device_initcall(smu_device_init);
