Logo Search packages:      
Sourcecode: linux version File versions  Download package

smu.c

/*
 * 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/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 <linux/mutex.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>
#include <asm/of_platform.h>

#define VERSION "0.7"
#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 */
      struct device_node      *db_node;
      unsigned int            db_irq;
      int               msg;
      struct device_node      *msg_node;
      unsigned 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;
static DEFINE_MUTEX(smu_part_access);
static int smu_irq_inited;

static void smu_i2c_retry(unsigned long data);

/*
 * 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 %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],
            ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
            ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);

      /* 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)
{
      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)
{
      /* 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);

      /* Workaround for early calls when irq isn't available */
      if (!smu_irq_inited || smu->db_irq == NO_IRQ)
            smu_spinwait_cmd(cmd);

      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);
}
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 __init smu_init (void)
{
      struct device_node *np;
      const 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;

      /* 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);

      smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
      if (smu->db_node == NULL) {
            printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
            goto fail;
      }
      data = of_get_property(smu->db_node, "reg", NULL);
      if (data == NULL) {
            of_node_put(smu->db_node);
            smu->db_node = NULL;
            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;

      /* Now look for the smu-interrupt GPIO */
      do {
            smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
            if (smu->msg_node == NULL)
                  break;
            data = of_get_property(smu->msg_node, "reg", NULL);
            if (data == NULL) {
                  of_node_put(smu->msg_node);
                  smu->msg_node = NULL;
                  break;
            }
            smu->msg = *data;
            if (smu->msg < 0x50)
                  smu->msg += 0x50;
      } 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;

      init_timer(&smu->i2c_timer);
      smu->i2c_timer.function = smu_i2c_retry;
      smu->i2c_timer.data = (unsigned long)smu;

      if (smu->db_node) {
            smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
            if (smu->db_irq == NO_IRQ)
                  printk(KERN_ERR "smu: failed to map irq for node %s\n",
                         smu->db_node->full_name);
      }
      if (smu->msg_node) {
            smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
            if (smu->msg_irq == NO_IRQ)
                  printk(KERN_ERR "smu: failed to map irq for node %s\n",
                         smu->msg_node->full_name);
      }

      /*
       * Try to request the interrupts
       */

      if (smu->db_irq != NO_IRQ) {
            if (request_irq(smu->db_irq, smu_db_intr,
                        IRQF_SHARED, "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,
                        IRQF_SHARED, "SMU message", smu) < 0) {
                  printk(KERN_WARNING "SMU: can't "
                         "request interrupt %d\n",
                         smu->msg_irq);
                  smu->msg_irq = NO_IRQ;
            }
      }

      smu_irq_inited = 1;
      return 0;
}
/* This has to be before arch_initcall as the low i2c stuff relies on the
 * above having been done before we reach arch_initcalls
 */
core_initcall(smu_late_init);

/*
 * sysfs visibility
 */

static void smu_expose_childs(struct work_struct *unused)
{
      struct device_node *np;

      for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
            if (of_device_is_compatible(np, "smu-sensors"))
                  of_platform_device_create(np, "smu-sensors",
                                      &smu->of_dev->dev);
}

static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);

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)
{
      /*
       * 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
       */
      of_register_platform_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 = smu->cmd_i2c_cur;

      DPRINTK("SMU: i2c failure, requeuing...\n");

      /* requeue command simply by resetting reply_len */
      cmd->pdata[0] = 0xff;
      cmd->scmd.reply_len = sizeof(cmd->pdata);
      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");
            BUG_ON(cmd != smu->cmd_i2c_cur);
            if (!smu_irq_inited) {
                  mdelay(5);
                  smu_i2c_retry(0);
                  return;
            }
            mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
            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 = sizeof(cmd->pdata);
      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 = sizeof(cmd->pdata);
      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;
}

/*
 * Handling of "partitions"
 */

static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
{
      DECLARE_COMPLETION_ONSTACK(comp);
      unsigned int chunk;
      struct smu_cmd cmd;
      int rc;
      u8 params[8];

      /* We currently use a chunk size of 0xe. We could check the
       * SMU firmware version and use bigger sizes though
       */
      chunk = 0xe;

      while (len) {
            unsigned int clen = min(len, chunk);

            cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
            cmd.data_len = 7;
            cmd.data_buf = params;
            cmd.reply_len = chunk;
            cmd.reply_buf = dest;
            cmd.done = smu_done_complete;
            cmd.misc = &comp;
            params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
            params[1] = 0x4;
            *((u32 *)&params[2]) = addr;
            params[6] = clen;

            rc = smu_queue_cmd(&cmd);
            if (rc)
                  return rc;
            wait_for_completion(&comp);
            if (cmd.status != 0)
                  return rc;
            if (cmd.reply_len != clen) {
                  printk(KERN_DEBUG "SMU: short read in "
                         "smu_read_datablock, got: %d, want: %d\n",
                         cmd.reply_len, clen);
                  return -EIO;
            }
            len -= clen;
            addr += clen;
            dest += clen;
      }
      return 0;
}

static struct smu_sdbp_header *smu_create_sdb_partition(int id)
{
      DECLARE_COMPLETION_ONSTACK(comp);
      struct smu_simple_cmd cmd;
      unsigned int addr, len, tlen;
      struct smu_sdbp_header *hdr;
      struct property *prop;

      /* First query the partition info */
      DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
      smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
                   smu_done_complete, &comp,
                   SMU_CMD_PARTITION_LATEST, id);
      wait_for_completion(&comp);
      DPRINTK("SMU: done, status: %d, reply_len: %d\n",
            cmd.cmd.status, cmd.cmd.reply_len);

      /* Partition doesn't exist (or other error) */
      if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
            return NULL;

      /* Fetch address and length from reply */
      addr = *((u16 *)cmd.buffer);
      len = cmd.buffer[3] << 2;
      /* Calucluate total length to allocate, including the 17 bytes
       * for "sdb-partition-XX" that we append at the end of the buffer
       */
      tlen = sizeof(struct property) + len + 18;

      prop = kzalloc(tlen, GFP_KERNEL);
      if (prop == NULL)
            return NULL;
      hdr = (struct smu_sdbp_header *)(prop + 1);
      prop->name = ((char *)prop) + tlen - 18;
      sprintf(prop->name, "sdb-partition-%02x", id);
      prop->length = len;
      prop->value = hdr;
      prop->next = NULL;

      /* Read the datablock */
      if (smu_read_datablock((u8 *)hdr, addr, len)) {
            printk(KERN_DEBUG "SMU: datablock read failed while reading "
                   "partition %02x !\n", id);
            goto failure;
      }

      /* Got it, check a few things and create the property */
      if (hdr->id != id) {
            printk(KERN_DEBUG "SMU: Reading partition %02x and got "
                   "%02x !\n", id, hdr->id);
            goto failure;
      }
      if (prom_add_property(smu->of_node, prop)) {
            printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
                   "property !\n", id);
            goto failure;
      }

      return hdr;
 failure:
      kfree(prop);
      return NULL;
}

/* Note: Only allowed to return error code in pointers (using ERR_PTR)
 * when interruptible is 1
 */
const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
            unsigned int *size, int interruptible)
{
      char pname[32];
      const struct smu_sdbp_header *part;

      if (!smu)
            return NULL;

      sprintf(pname, "sdb-partition-%02x", id);

      DPRINTK("smu_get_sdb_partition(%02x)\n", id);

      if (interruptible) {
            int rc;
            rc = mutex_lock_interruptible(&smu_part_access);
            if (rc)
                  return ERR_PTR(rc);
      } else
            mutex_lock(&smu_part_access);

      part = of_get_property(smu->of_node, pname, size);
      if (part == NULL) {
            DPRINTK("trying to extract from SMU ...\n");
            part = smu_create_sdb_partition(id);
            if (part != NULL && size)
                  *size = part->len << 2;
      }
      mutex_unlock(&smu_part_access);
      return part;
}

const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
{
      return __smu_get_sdb_partition(id, size, 0);
}
EXPORT_SYMBOL(smu_get_sdb_partition);


/*
 * 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 = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
      if (pp == 0)
            return -ENOMEM;
      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_GET_PARTITION) {
            const struct smu_sdbp_header *part;
            part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
            if (part == NULL)
                  return -EINVAL;
            else if (IS_ERR(part))
                  return PTR_ERR(part);
            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_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);

      spin_lock_irqsave(&smu_clist_lock, flags);
      list_del(&pp->list);
      spin_unlock_irqrestore(&smu_clist_lock, flags);
      kfree(pp);

      return 0;
}


static const 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);

Generated by  Doxygen 1.6.0   Back to index