// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * FIXME: Properly make this race free with refcounting etc...
 *
 * FIXME: LOCKING !!!
 */

#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 <linux/of.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_obj(*func);
                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_each_property_of_node(dev->node, pp) {
                const 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 %pOF\n", np);

        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_obj(*dev);
        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 %pOF\n", np);

        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);

static 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(%pOF/%s) **\n", dev->node, 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);