pfunc_core.c

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/*
 *
 * FIXME: Properly make this race free with refcounting etc...
 *
 * FIXME: LOCKING !!!
 */

#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mutex.h>

#include <asm/prom.h>
#include <asm/pmac_pfunc.h>

/* Debug */
#define LOG_PARSE(fmt...)
#define LOG_ERROR(fmt...)   printk(fmt)
#define LOG_BLOB(t,b,c)

#undef DEBUG
#ifdef DEBUG
#define DBG(fmt...)     printk(fmt)
#else
#define DBG(fmt...)
#endif

/* Command numbers */
#define PMF_CMD_LIST            0
#define PMF_CMD_WRITE_GPIO      1
#define PMF_CMD_READ_GPIO       2
#define PMF_CMD_WRITE_REG32     3
#define PMF_CMD_READ_REG32      4
#define PMF_CMD_WRITE_REG16     5
#define PMF_CMD_READ_REG16      6
#define PMF_CMD_WRITE_REG8      7
#define PMF_CMD_READ_REG8       8
#define PMF_CMD_DELAY           9
#define PMF_CMD_WAIT_REG32      10
#define PMF_CMD_WAIT_REG16      11
#define PMF_CMD_WAIT_REG8       12
#define PMF_CMD_READ_I2C        13
#define PMF_CMD_WRITE_I2C       14
#define PMF_CMD_RMW_I2C         15
#define PMF_CMD_GEN_I2C         16
#define PMF_CMD_SHIFT_BYTES_RIGHT   17
#define PMF_CMD_SHIFT_BYTES_LEFT    18
#define PMF_CMD_READ_CFG        19
#define PMF_CMD_WRITE_CFG       20
#define PMF_CMD_RMW_CFG         21
#define PMF_CMD_READ_I2C_SUBADDR    22
#define PMF_CMD_WRITE_I2C_SUBADDR   23
#define PMF_CMD_SET_I2C_MODE        24
#define PMF_CMD_RMW_I2C_SUBADDR     25
#define PMF_CMD_READ_REG32_MASK_SHR_XOR 26
#define PMF_CMD_READ_REG16_MASK_SHR_XOR 27
#define PMF_CMD_READ_REG8_MASK_SHR_XOR  28
#define PMF_CMD_WRITE_REG32_SHL_MASK    29
#define PMF_CMD_WRITE_REG16_SHL_MASK    30
#define PMF_CMD_WRITE_REG8_SHL_MASK 31
#define PMF_CMD_MASK_AND_COMPARE    32
#define PMF_CMD_COUNT           33

/* This structure holds the state of the parser while walking through
 * a function definition
 */
struct pmf_cmd {
    const void      *cmdptr;
    const void      *cmdend;
    struct pmf_function *func;
    void            *instdata;
    struct pmf_args     *args;
    int         error;
};

#if 0
/* Debug output */
static void print_blob(const char *title, const void *blob, int bytes)
{
    printk("%s", title);
    while(bytes--) {
        printk("%02x ", *((u8 *)blob));
        blob += 1;
    }
    printk("\n");
}
#endif

/*
 * Parser helpers
 */

static u32 pmf_next32(struct pmf_cmd *cmd)
{
    u32 value;
    if ((cmd->cmdend - cmd->cmdptr) < 4) {
        cmd->error = 1;
        return 0;
    }
    value = *((u32 *)cmd->cmdptr);
    cmd->cmdptr += 4;
    return value;
}

static const void* pmf_next_blob(struct pmf_cmd *cmd, int count)
{
    const void *value;
    if ((cmd->cmdend - cmd->cmdptr) < count) {
        cmd->error = 1;
        return NULL;
    }
    value = cmd->cmdptr;
    cmd->cmdptr += count;
    return value;
}

/*
 * Individual command parsers
 */

#define PMF_PARSE_CALL(name, cmd, handlers, p...) \
    do { \
        if (cmd->error) \
            return -ENXIO; \
        if (handlers == NULL) \
            return 0; \
        if (handlers->name)                   \
            return handlers->name(cmd->func, cmd->instdata, \
                          cmd->args, p);          \
        return -1; \
    } while(0) \


static int pmf_parser_write_gpio(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u8 value = (u8)pmf_next32(cmd);
    u8 mask = (u8)pmf_next32(cmd);

    LOG_PARSE("pmf: write_gpio(value: %02x, mask: %02x)\n", value, mask);

    PMF_PARSE_CALL(write_gpio, cmd, h, value, mask);
}

static int pmf_parser_read_gpio(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u8 mask = (u8)pmf_next32(cmd);
    int rshift = (int)pmf_next32(cmd);
    u8 xor = (u8)pmf_next32(cmd);

    LOG_PARSE("pmf: read_gpio(mask: %02x, rshift: %d, xor: %02x)\n",
          mask, rshift, xor);

    PMF_PARSE_CALL(read_gpio, cmd, h, mask, rshift, xor);
}

static int pmf_parser_write_reg32(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 value = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);

    LOG_PARSE("pmf: write_reg32(offset: %08x, value: %08x, mask: %08x)\n",
          offset, value, mask);

    PMF_PARSE_CALL(write_reg32, cmd, h, offset, value, mask);
}

static int pmf_parser_read_reg32(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);

    LOG_PARSE("pmf: read_reg32(offset: %08x)\n", offset);

    PMF_PARSE_CALL(read_reg32, cmd, h, offset);
}


static int pmf_parser_write_reg16(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u16 value = (u16)pmf_next32(cmd);
    u16 mask = (u16)pmf_next32(cmd);

    LOG_PARSE("pmf: write_reg16(offset: %08x, value: %04x, mask: %04x)\n",
          offset, value, mask);

    PMF_PARSE_CALL(write_reg16, cmd, h, offset, value, mask);
}

static int pmf_parser_read_reg16(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);

    LOG_PARSE("pmf: read_reg16(offset: %08x)\n", offset);

    PMF_PARSE_CALL(read_reg16, cmd, h, offset);
}


static int pmf_parser_write_reg8(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u8 value = (u16)pmf_next32(cmd);
    u8 mask = (u16)pmf_next32(cmd);

    LOG_PARSE("pmf: write_reg8(offset: %08x, value: %02x, mask: %02x)\n",
          offset, value, mask);

    PMF_PARSE_CALL(write_reg8, cmd, h, offset, value, mask);
}

static int pmf_parser_read_reg8(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);

    LOG_PARSE("pmf: read_reg8(offset: %08x)\n", offset);

    PMF_PARSE_CALL(read_reg8, cmd, h, offset);
}

static int pmf_parser_delay(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 duration = pmf_next32(cmd);

    LOG_PARSE("pmf: delay(duration: %d us)\n", duration);

    PMF_PARSE_CALL(delay, cmd, h, duration);
}

static int pmf_parser_wait_reg32(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 value = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);

    LOG_PARSE("pmf: wait_reg32(offset: %08x, comp_value: %08x,mask: %08x)\n",
          offset, value, mask);

    PMF_PARSE_CALL(wait_reg32, cmd, h, offset, value, mask);
}

static int pmf_parser_wait_reg16(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u16 value = (u16)pmf_next32(cmd);
    u16 mask = (u16)pmf_next32(cmd);

    LOG_PARSE("pmf: wait_reg16(offset: %08x, comp_value: %04x,mask: %04x)\n",
          offset, value, mask);

    PMF_PARSE_CALL(wait_reg16, cmd, h, offset, value, mask);
}

static int pmf_parser_wait_reg8(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u8 value = (u8)pmf_next32(cmd);
    u8 mask = (u8)pmf_next32(cmd);

    LOG_PARSE("pmf: wait_reg8(offset: %08x, comp_value: %02x,mask: %02x)\n",
          offset, value, mask);

    PMF_PARSE_CALL(wait_reg8, cmd, h, offset, value, mask);
}

static int pmf_parser_read_i2c(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 bytes = pmf_next32(cmd);

    LOG_PARSE("pmf: read_i2c(bytes: %ud)\n", bytes);

    PMF_PARSE_CALL(read_i2c, cmd, h, bytes);
}

static int pmf_parser_write_i2c(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 bytes = pmf_next32(cmd);
    const void *blob = pmf_next_blob(cmd, bytes);

    LOG_PARSE("pmf: write_i2c(bytes: %ud) ...\n", bytes);
    LOG_BLOB("pmf:   data: \n", blob, bytes);

    PMF_PARSE_CALL(write_i2c, cmd, h, bytes, blob);
}


static int pmf_parser_rmw_i2c(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 maskbytes = pmf_next32(cmd);
    u32 valuesbytes = pmf_next32(cmd);
    u32 totalbytes = pmf_next32(cmd);
    const void *maskblob = pmf_next_blob(cmd, maskbytes);
    const void *valuesblob = pmf_next_blob(cmd, valuesbytes);

    LOG_PARSE("pmf: rmw_i2c(maskbytes: %ud, valuebytes: %ud, "
          "totalbytes: %d) ...\n",
          maskbytes, valuesbytes, totalbytes);
    LOG_BLOB("pmf:   mask data: \n", maskblob, maskbytes);
    LOG_BLOB("pmf:   values data: \n", valuesblob, valuesbytes);

    PMF_PARSE_CALL(rmw_i2c, cmd, h, maskbytes, valuesbytes, totalbytes,
               maskblob, valuesblob);
}

static int pmf_parser_read_cfg(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 bytes = pmf_next32(cmd);

    LOG_PARSE("pmf: read_cfg(offset: %x, bytes: %ud)\n", offset, bytes);

    PMF_PARSE_CALL(read_cfg, cmd, h, offset, bytes);
}


static int pmf_parser_write_cfg(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 bytes = pmf_next32(cmd);
    const void *blob = pmf_next_blob(cmd, bytes);

    LOG_PARSE("pmf: write_cfg(offset: %x, bytes: %ud)\n", offset, bytes);
    LOG_BLOB("pmf:   data: \n", blob, bytes);

    PMF_PARSE_CALL(write_cfg, cmd, h, offset, bytes, blob);
}

static int pmf_parser_rmw_cfg(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 maskbytes = pmf_next32(cmd);
    u32 valuesbytes = pmf_next32(cmd);
    u32 totalbytes = pmf_next32(cmd);
    const void *maskblob = pmf_next_blob(cmd, maskbytes);
    const void *valuesblob = pmf_next_blob(cmd, valuesbytes);

    LOG_PARSE("pmf: rmw_cfg(maskbytes: %ud, valuebytes: %ud,"
          " totalbytes: %d) ...\n",
          maskbytes, valuesbytes, totalbytes);
    LOG_BLOB("pmf:   mask data: \n", maskblob, maskbytes);
    LOG_BLOB("pmf:   values data: \n", valuesblob, valuesbytes);

    PMF_PARSE_CALL(rmw_cfg, cmd, h, offset, maskbytes, valuesbytes,
               totalbytes, maskblob, valuesblob);
}


static int pmf_parser_read_i2c_sub(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u8 subaddr = (u8)pmf_next32(cmd);
    u32 bytes = pmf_next32(cmd);

    LOG_PARSE("pmf: read_i2c_sub(subaddr: %x, bytes: %ud)\n",
          subaddr, bytes);

    PMF_PARSE_CALL(read_i2c_sub, cmd, h, subaddr, bytes);
}

static int pmf_parser_write_i2c_sub(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u8 subaddr = (u8)pmf_next32(cmd);
    u32 bytes = pmf_next32(cmd);
    const void *blob = pmf_next_blob(cmd, bytes);

    LOG_PARSE("pmf: write_i2c_sub(subaddr: %x, bytes: %ud) ...\n",
          subaddr, bytes);
    LOG_BLOB("pmf:   data: \n", blob, bytes);

    PMF_PARSE_CALL(write_i2c_sub, cmd, h, subaddr, bytes, blob);
}

static int pmf_parser_set_i2c_mode(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u32 mode = pmf_next32(cmd);

    LOG_PARSE("pmf: set_i2c_mode(mode: %d)\n", mode);

    PMF_PARSE_CALL(set_i2c_mode, cmd, h, mode);
}


static int pmf_parser_rmw_i2c_sub(struct pmf_cmd *cmd, struct pmf_handlers *h)
{
    u8 subaddr = (u8)pmf_next32(cmd);
    u32 maskbytes = pmf_next32(cmd);
    u32 valuesbytes = pmf_next32(cmd);
    u32 totalbytes = pmf_next32(cmd);
    const void *maskblob = pmf_next_blob(cmd, maskbytes);
    const void *valuesblob = pmf_next_blob(cmd, valuesbytes);

    LOG_PARSE("pmf: rmw_i2c_sub(subaddr: %x, maskbytes: %ud, valuebytes: %ud"
          ", totalbytes: %d) ...\n",
          subaddr, maskbytes, valuesbytes, totalbytes);
    LOG_BLOB("pmf:   mask data: \n", maskblob, maskbytes);
    LOG_BLOB("pmf:   values data: \n", valuesblob, valuesbytes);

    PMF_PARSE_CALL(rmw_i2c_sub, cmd, h, subaddr, maskbytes, valuesbytes,
               totalbytes, maskblob, valuesblob);
}

static int pmf_parser_read_reg32_msrx(struct pmf_cmd *cmd,
                      struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);
    u32 shift = pmf_next32(cmd);
    u32 xor = pmf_next32(cmd);

    LOG_PARSE("pmf: read_reg32_msrx(offset: %x, mask: %x, shift: %x,"
          " xor: %x\n", offset, mask, shift, xor);

    PMF_PARSE_CALL(read_reg32_msrx, cmd, h, offset, mask, shift, xor);
}

static int pmf_parser_read_reg16_msrx(struct pmf_cmd *cmd,
                      struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);
    u32 shift = pmf_next32(cmd);
    u32 xor = pmf_next32(cmd);

    LOG_PARSE("pmf: read_reg16_msrx(offset: %x, mask: %x, shift: %x,"
          " xor: %x\n", offset, mask, shift, xor);

    PMF_PARSE_CALL(read_reg16_msrx, cmd, h, offset, mask, shift, xor);
}
static int pmf_parser_read_reg8_msrx(struct pmf_cmd *cmd,
                     struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);
    u32 shift = pmf_next32(cmd);
    u32 xor = pmf_next32(cmd);

    LOG_PARSE("pmf: read_reg8_msrx(offset: %x, mask: %x, shift: %x,"
          " xor: %x\n", offset, mask, shift, xor);

    PMF_PARSE_CALL(read_reg8_msrx, cmd, h, offset, mask, shift, xor);
}

static int pmf_parser_write_reg32_slm(struct pmf_cmd *cmd,
                      struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 shift = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);

    LOG_PARSE("pmf: write_reg32_slm(offset: %x, shift: %x, mask: %x\n",
          offset, shift, mask);

    PMF_PARSE_CALL(write_reg32_slm, cmd, h, offset, shift, mask);
}

static int pmf_parser_write_reg16_slm(struct pmf_cmd *cmd,
                      struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 shift = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);

    LOG_PARSE("pmf: write_reg16_slm(offset: %x, shift: %x, mask: %x\n",
          offset, shift, mask);

    PMF_PARSE_CALL(write_reg16_slm, cmd, h, offset, shift, mask);
}

static int pmf_parser_write_reg8_slm(struct pmf_cmd *cmd,
                     struct pmf_handlers *h)
{
    u32 offset = pmf_next32(cmd);
    u32 shift = pmf_next32(cmd);
    u32 mask = pmf_next32(cmd);

    LOG_PARSE("pmf: write_reg8_slm(offset: %x, shift: %x, mask: %x\n",
          offset, shift, mask);

    PMF_PARSE_CALL(write_reg8_slm, cmd, h, offset, shift, mask);
}

static int pmf_parser_mask_and_compare(struct pmf_cmd *cmd,
                       struct pmf_handlers *h)
{
    u32 bytes = pmf_next32(cmd);
    const void *maskblob = pmf_next_blob(cmd, bytes);
    const void *valuesblob = pmf_next_blob(cmd, bytes);

    LOG_PARSE("pmf: mask_and_compare(length: %ud ...\n", bytes);
    LOG_BLOB("pmf:   mask data: \n", maskblob, bytes);
    LOG_BLOB("pmf:   values data: \n", valuesblob, bytes);

    PMF_PARSE_CALL(mask_and_compare, cmd, h,
               bytes, maskblob, valuesblob);
}


typedef int (*pmf_cmd_parser_t)(struct pmf_cmd *cmd, struct pmf_handlers *h);

static pmf_cmd_parser_t pmf_parsers[PMF_CMD_COUNT] =
{
    NULL,
    pmf_parser_write_gpio,
    pmf_parser_read_gpio,
    pmf_parser_write_reg32,
    pmf_parser_read_reg32,
    pmf_parser_write_reg16,
    pmf_parser_read_reg16,
    pmf_parser_write_reg8,
    pmf_parser_read_reg8,
    pmf_parser_delay,
    pmf_parser_wait_reg32,
    pmf_parser_wait_reg16,
    pmf_parser_wait_reg8,
    pmf_parser_read_i2c,
    pmf_parser_write_i2c,
    pmf_parser_rmw_i2c,
    NULL, /* Bogus command */
    NULL, /* Shift bytes right: NYI */
    NULL, /* Shift bytes left: NYI */
    pmf_parser_read_cfg,
    pmf_parser_write_cfg,
    pmf_parser_rmw_cfg,
    pmf_parser_read_i2c_sub,
    pmf_parser_write_i2c_sub,
    pmf_parser_set_i2c_mode,
    pmf_parser_rmw_i2c_sub,
    pmf_parser_read_reg32_msrx,
    pmf_parser_read_reg16_msrx,
    pmf_parser_read_reg8_msrx,
    pmf_parser_write_reg32_slm,
    pmf_parser_write_reg16_slm,
    pmf_parser_write_reg8_slm,
    pmf_parser_mask_and_compare,
};

struct pmf_device {
    struct list_head    link;
    struct device_node  *node;
    struct pmf_handlers *handlers;
    struct list_head    functions;
    struct kref     ref;
};

static LIST_HEAD(pmf_devices);
static DEFINE_SPINLOCK(pmf_lock);
static DEFINE_MUTEX(pmf_irq_mutex);

static void pmf_release_device(struct kref *kref)
{
    struct pmf_device *dev = container_of(kref, struct pmf_device, ref);
    kfree(dev);
}

static inline void pmf_put_device(struct pmf_device *dev)
{
    kref_put(&dev->ref, pmf_release_device);
}

static inline struct pmf_device *pmf_get_device(struct pmf_device *dev)
{
    kref_get(&dev->ref);
    return dev;
}

static inline struct pmf_device *pmf_find_device(struct device_node *np)
{
    struct pmf_device *dev;

    list_for_each_entry(dev, &pmf_devices, link) {
        if (dev->node == np)
            return pmf_get_device(dev);
    }
    return NULL;
}

static int pmf_parse_one(struct pmf_function *func,
             struct pmf_handlers *handlers,
             void *instdata, struct pmf_args *args)
{
    struct pmf_cmd cmd;
    u32 ccode;
    int count, rc;

    cmd.cmdptr      = func->data;
    cmd.cmdend      = func->data + func->length;
    cmd.func            = func;
    cmd.instdata        = instdata;
    cmd.args        = args;
    cmd.error       = 0;

    LOG_PARSE("pmf: func %s, %d bytes, %s...\n",
          func->name, func->length,
          handlers ? "executing" : "parsing");

    /* One subcommand to parse for now */
    count = 1;

    while(count-- && cmd.cmdptr < cmd.cmdend) {
        /* Get opcode */
        ccode = pmf_next32(&cmd);
        /* Check if we are hitting a command list, fetch new count */
        if (ccode == 0) {
            count = pmf_next32(&cmd) - 1;
            ccode = pmf_next32(&cmd);
        }
        if (cmd.error) {
            LOG_ERROR("pmf: parse error, not enough data\n");
            return -ENXIO;
        }
        if (ccode >= PMF_CMD_COUNT) {
            LOG_ERROR("pmf: command code %d unknown !\n", ccode);
            return -ENXIO;
        }
        if (pmf_parsers[ccode] == NULL) {
            LOG_ERROR("pmf: no parser for command %d !\n", ccode);
            return -ENXIO;
        }
        rc = pmf_parsers[ccode](&cmd, handlers);
        if (rc != 0) {
            LOG_ERROR("pmf: parser for command %d returned"
                  " error %d\n", ccode, rc);
            return rc;
        }
    }

    /* We are doing an initial parse pass, we need to adjust the size */
    if (handlers == NULL)
        func->length = cmd.cmdptr - func->data;

    return 0;
}

static int pmf_add_function_prop(struct pmf_device *dev, void *driverdata,
                 const char *name, u32 *data,
                 unsigned int length)
{
    int count = 0;
    struct pmf_function *func = NULL;

    DBG("pmf: Adding functions for platform-do-%s\n", name);

    while (length >= 12) {
        /* Allocate a structure */
        func = kzalloc(sizeof(struct pmf_function), GFP_KERNEL);
        if (func == NULL)
            goto bail;
        kref_init(&func->ref);
        INIT_LIST_HEAD(&func->irq_clients);
        func->node = dev->node;
        func->driver_data = driverdata;
        func->name = name;
        func->phandle = data[0];
        func->flags = data[1];
        data += 2;
        length -= 8;
        func->data = data;
        func->length = length;
        func->dev = dev;
        DBG("pmf: idx %d: flags=%08x, phandle=%08x "
            " %d bytes remaining, parsing...\n",
            count+1, func->flags, func->phandle, length);
        if (pmf_parse_one(func, NULL, NULL, NULL)) {
            kfree(func);
            goto bail;
        }
        length -= func->length;
        data = (u32 *)(((u8 *)data) + func->length);
        list_add(&func->link, &dev->functions);
        pmf_get_device(dev);
        count++;
    }
 bail:
    DBG("pmf: Added %d functions\n", count);

    return count;
}

static int pmf_add_functions(struct pmf_device *dev, void *driverdata)
{
    struct property *pp;
#define PP_PREFIX "platform-do-"
    const int plen = strlen(PP_PREFIX);
    int count = 0;

    for (pp = dev->node->properties; pp != 0; pp = pp->next) {
        char *name;
        if (strncmp(pp->name, PP_PREFIX, plen) != 0)
            continue;
        name = pp->name + plen;
        if (strlen(name) && pp->length >= 12)
            count += pmf_add_function_prop(dev, driverdata, name,
                               pp->value, pp->length);
    }
    return count;
}


int pmf_register_driver(struct device_node *np,
            struct pmf_handlers *handlers,
            void *driverdata)
{
    struct pmf_device *dev;
    unsigned long flags;
    int rc = 0;

    if (handlers == NULL)
        return -EINVAL;

    DBG("pmf: registering driver for node %s\n", np->full_name);

    spin_lock_irqsave(&pmf_lock, flags);
    dev = pmf_find_device(np);
    spin_unlock_irqrestore(&pmf_lock, flags);
    if (dev != NULL) {
        DBG("pmf: already there !\n");
        pmf_put_device(dev);
        return -EBUSY;
    }

    dev = kzalloc(sizeof(struct pmf_device), GFP_KERNEL);
    if (dev == NULL) {
        DBG("pmf: no memory !\n");
        return -ENOMEM;
    }
    kref_init(&dev->ref);
    dev->node = of_node_get(np);
    dev->handlers = handlers;
    INIT_LIST_HEAD(&dev->functions);

    rc = pmf_add_functions(dev, driverdata);
    if (rc == 0) {
        DBG("pmf: no functions, disposing.. \n");
        of_node_put(np);
        kfree(dev);
        return -ENODEV;
    }

    spin_lock_irqsave(&pmf_lock, flags);
    list_add(&dev->link, &pmf_devices);
    spin_unlock_irqrestore(&pmf_lock, flags);

    return 0;
}
EXPORT_SYMBOL_GPL(pmf_register_driver);

struct pmf_function *pmf_get_function(struct pmf_function *func)
{
    if (!try_module_get(func->dev->handlers->owner))
        return NULL;
    kref_get(&func->ref);
    return func;
}
EXPORT_SYMBOL_GPL(pmf_get_function);

static void pmf_release_function(struct kref *kref)
{
    struct pmf_function *func =
        container_of(kref, struct pmf_function, ref);
    pmf_put_device(func->dev);
    kfree(func);
}

static inline void __pmf_put_function(struct pmf_function *func)
{
    kref_put(&func->ref, pmf_release_function);
}

void pmf_put_function(struct pmf_function *func)
{
    if (func == NULL)
        return;
    module_put(func->dev->handlers->owner);
    __pmf_put_function(func);
}
EXPORT_SYMBOL_GPL(pmf_put_function);

void pmf_unregister_driver(struct device_node *np)
{
    struct pmf_device *dev;
    unsigned long flags;

    DBG("pmf: unregistering driver for node %s\n", np->full_name);

    spin_lock_irqsave(&pmf_lock, flags);
    dev = pmf_find_device(np);
    if (dev == NULL) {
        DBG("pmf: not such driver !\n");
        spin_unlock_irqrestore(&pmf_lock, flags);
        return;
    }
    list_del(&dev->link);

    while(!list_empty(&dev->functions)) {
        struct pmf_function *func =
            list_entry(dev->functions.next, typeof(*func), link);
        list_del(&func->link);
        __pmf_put_function(func);
    }

    pmf_put_device(dev);
    spin_unlock_irqrestore(&pmf_lock, flags);
}
EXPORT_SYMBOL_GPL(pmf_unregister_driver);

struct pmf_function *__pmf_find_function(struct device_node *target,
                     const char *name, u32 flags)
{
    struct device_node *actor = of_node_get(target);
    struct pmf_device *dev;
    struct pmf_function *func, *result = NULL;
    char fname[64];
    const u32 *prop;
    u32 ph;

    /*
     * Look for a "platform-*" function reference. If we can't find
     * one, then we fallback to a direct call attempt
     */
    snprintf(fname, 63, "platform-%s", name);
    prop = of_get_property(target, fname, NULL);
    if (prop == NULL)
        goto find_it;
    ph = *prop;
    if (ph == 0)
        goto find_it;

    /*
     * Ok, now try to find the actor. If we can't find it, we fail,
     * there is no point in falling back there
     */
    of_node_put(actor);
    actor = of_find_node_by_phandle(ph);
    if (actor == NULL)
        return NULL;
 find_it:
    dev = pmf_find_device(actor);
    if (dev == NULL) {
        result = NULL;
        goto out;
    }

    list_for_each_entry(func, &dev->functions, link) {
        if (name && strcmp(name, func->name))
            continue;
        if (func->phandle && target->phandle != func->phandle)
            continue;
        if ((func->flags & flags) == 0)
            continue;
        result = func;
        break;
    }
    pmf_put_device(dev);
out:
    of_node_put(actor);
    return result;
}


int pmf_register_irq_client(struct device_node *target,
                const char *name,
                struct pmf_irq_client *client)
{
    struct pmf_function *func;
    unsigned long flags;

    spin_lock_irqsave(&pmf_lock, flags);
    func = __pmf_find_function(target, name, PMF_FLAGS_INT_GEN);
    if (func)
        func = pmf_get_function(func);
    spin_unlock_irqrestore(&pmf_lock, flags);
    if (func == NULL)
        return -ENODEV;

    /* guard against manipulations of list */
    mutex_lock(&pmf_irq_mutex);
    if (list_empty(&func->irq_clients))
        func->dev->handlers->irq_enable(func);

    /* guard against pmf_do_irq while changing list */
    spin_lock_irqsave(&pmf_lock, flags);
    list_add(&client->link, &func->irq_clients);
    spin_unlock_irqrestore(&pmf_lock, flags);

    client->func = func;
    mutex_unlock(&pmf_irq_mutex);

    return 0;
}
EXPORT_SYMBOL_GPL(pmf_register_irq_client);

void pmf_unregister_irq_client(struct pmf_irq_client *client)
{
    struct pmf_function *func = client->func;
    unsigned long flags;

    BUG_ON(func == NULL);

    /* guard against manipulations of list */
    mutex_lock(&pmf_irq_mutex);
    client->func = NULL;

    /* guard against pmf_do_irq while changing list */
    spin_lock_irqsave(&pmf_lock, flags);
    list_del(&client->link);
    spin_unlock_irqrestore(&pmf_lock, flags);

    if (list_empty(&func->irq_clients))
        func->dev->handlers->irq_disable(func);
    mutex_unlock(&pmf_irq_mutex);
    pmf_put_function(func);
}
EXPORT_SYMBOL_GPL(pmf_unregister_irq_client);


void pmf_do_irq(struct pmf_function *func)
{
    unsigned long flags;
    struct pmf_irq_client *client;

    /* For now, using a spinlock over the whole function. Can be made
     * to drop the lock using 2 lists if necessary
     */
    spin_lock_irqsave(&pmf_lock, flags);
    list_for_each_entry(client, &func->irq_clients, link) {
        if (!try_module_get(client->owner))
            continue;
        client->handler(client->data);
        module_put(client->owner);
    }
    spin_unlock_irqrestore(&pmf_lock, flags);
}
EXPORT_SYMBOL_GPL(pmf_do_irq);


int pmf_call_one(struct pmf_function *func, struct pmf_args *args)
{
    struct pmf_device *dev = func->dev;
    void *instdata = NULL;
    int rc = 0;

    DBG(" ** pmf_call_one(%s/%s) **\n", dev->node->full_name, func->name);

    if (dev->handlers->begin)
        instdata = dev->handlers->begin(func, args);
    rc = pmf_parse_one(func, dev->handlers, instdata, args);
    if (dev->handlers->end)
        dev->handlers->end(func, instdata);

    return rc;
}
EXPORT_SYMBOL_GPL(pmf_call_one);

int pmf_do_functions(struct device_node *np, const char *name,
             u32 phandle, u32 fflags, struct pmf_args *args)
{
    struct pmf_device *dev;
    struct pmf_function *func, *tmp;
    unsigned long flags;
    int rc = -ENODEV;

    spin_lock_irqsave(&pmf_lock, flags);

    dev = pmf_find_device(np);
    if (dev == NULL) {
        spin_unlock_irqrestore(&pmf_lock, flags);
        return -ENODEV;
    }
    list_for_each_entry_safe(func, tmp, &dev->functions, link) {
        if (name && strcmp(name, func->name))
            continue;
        if (phandle && func->phandle && phandle != func->phandle)
            continue;
        if ((func->flags & fflags) == 0)
            continue;
        if (pmf_get_function(func) == NULL)
            continue;
        spin_unlock_irqrestore(&pmf_lock, flags);
        rc = pmf_call_one(func, args);
        pmf_put_function(func);
        spin_lock_irqsave(&pmf_lock, flags);
    }
    pmf_put_device(dev);
    spin_unlock_irqrestore(&pmf_lock, flags);

    return rc;
}
EXPORT_SYMBOL_GPL(pmf_do_functions);


struct pmf_function *pmf_find_function(struct device_node *target,
                       const char *name)
{
    struct pmf_function *func;
    unsigned long flags;

    spin_lock_irqsave(&pmf_lock, flags);
    func = __pmf_find_function(target, name, PMF_FLAGS_ON_DEMAND);
    if (func)
        func = pmf_get_function(func);
    spin_unlock_irqrestore(&pmf_lock, flags);
    return func;
}
EXPORT_SYMBOL_GPL(pmf_find_function);

int pmf_call_function(struct device_node *target, const char *name,
              struct pmf_args *args)
{
    struct pmf_function *func = pmf_find_function(target, name);
    int rc;

    if (func == NULL)
        return -ENODEV;

    rc = pmf_call_one(func, args);
    pmf_put_function(func);
    return rc;
}
EXPORT_SYMBOL_GPL(pmf_call_function);