#include <common.h>
#include <console.h>
#include "e1000.h"
#include <linux/compiler.h>

/*-----------------------------------------------------------------------
 * SPI transfer
 *
 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
 * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
 *
 * The source of the outgoing bits is the "dout" parameter and the
 * destination of the input bits is the "din" parameter.  Note that "dout"
 * and "din" can point to the same memory location, in which case the
 * input data overwrites the output data (since both are buffered by
 * temporary variables, this is OK).
 *
 * This may be interrupted with Ctrl-C if "intr" is true, otherwise it will
 * never return an error.
 */
static int e1000_spi_xfer(struct e1000_hw *hw, unsigned int bitlen,
                const void *dout_mem, void *din_mem, bool intr)
{
        const uint8_t *dout = dout_mem;
        uint8_t *din = din_mem;

        uint8_t mask = 0;
        uint32_t eecd;
        unsigned long i;

        /* Pre-read the control register */
        eecd = E1000_READ_REG(hw, EECD);

        /* Iterate over each bit */
        for (i = 0, mask = 0x80; i < bitlen; i++, mask = (mask >> 1)?:0x80) {
                /* Check for interrupt */
                if (intr && ctrlc())
                        return -1;

                /* Determine the output bit */
                if (dout && dout[i >> 3] & mask)
                        eecd |=  E1000_EECD_DI;
                else
                        eecd &= ~E1000_EECD_DI;

                /* Write the output bit and wait 50us */
                E1000_WRITE_REG(hw, EECD, eecd);
                E1000_WRITE_FLUSH(hw);
                udelay(50);

                /* Poke the clock (waits 50us) */
                e1000_raise_ee_clk(hw, &eecd);

                /* Now read the input bit */
                eecd = E1000_READ_REG(hw, EECD);
                if (din) {
                        if (eecd & E1000_EECD_DO)
                                din[i >> 3] |=  mask;
                        else
                                din[i >> 3] &= ~mask;
                }

                /* Poke the clock again (waits 50us) */
                e1000_lower_ee_clk(hw, &eecd);
        }

        /* Now clear any remaining bits of the input */
        if (din && (i & 7))
                din[i >> 3] &= ~((mask << 1) - 1);

        return 0;
}

#ifdef CONFIG_E1000_SPI_GENERIC
static inline struct e1000_hw *e1000_hw_from_spi(struct spi_slave *spi)
{
        return container_of(spi, struct e1000_hw, spi);
}

/* Not sure why all of these are necessary */
void spi_init_r(void) { /* Nothing to do */ }
void spi_init_f(void) { /* Nothing to do */ }
void spi_init(void)   { /* Nothing to do */ }

struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
                unsigned int max_hz, unsigned int mode)
{
        /* Find the right PCI device */
        struct e1000_hw *hw = e1000_find_card(bus);
        if (!hw) {
                printf("ERROR: No such e1000 device: e1000#%u\n", bus);
                return NULL;
        }

        /* Make sure it has an SPI chip */
        if (hw->eeprom.type != e1000_eeprom_spi) {
                E1000_ERR(hw, "No attached SPI EEPROM found!\n");
                return NULL;
        }

        /* Argument sanity checks */
        if (cs != 0) {
                E1000_ERR(hw, "No such SPI chip: %u\n", cs);
                return NULL;
        }
        if (mode != SPI_MODE_0) {
                E1000_ERR(hw, "Only SPI MODE-0 is supported!\n");
                return NULL;
        }

        /* TODO: Use max_hz somehow */
        E1000_DBG(hw->nic, "EEPROM SPI access requested\n");
        return &hw->spi;
}

void spi_free_slave(struct spi_slave *spi)
{
        __maybe_unused struct e1000_hw *hw = e1000_hw_from_spi(spi);
        E1000_DBG(hw->nic, "EEPROM SPI access released\n");
}

int spi_claim_bus(struct spi_slave *spi)
{
        struct e1000_hw *hw = e1000_hw_from_spi(spi);

        if (e1000_acquire_eeprom(hw)) {
                E1000_ERR(hw, "EEPROM SPI cannot be acquired!\n");
                return -1;
        }

        return 0;
}

void spi_release_bus(struct spi_slave *spi)
{
        struct e1000_hw *hw = e1000_hw_from_spi(spi);
        e1000_release_eeprom(hw);
}

/* Skinny wrapper around e1000_spi_xfer */
int spi_xfer(struct spi_slave *spi, unsigned int bitlen,
                const void *dout_mem, void *din_mem, unsigned long flags)
{
        struct e1000_hw *hw = e1000_hw_from_spi(spi);
        int ret;

        if (flags & SPI_XFER_BEGIN)
                e1000_standby_eeprom(hw);

        ret = e1000_spi_xfer(hw, bitlen, dout_mem, din_mem, true);

        if (flags & SPI_XFER_END)
                e1000_standby_eeprom(hw);

        return ret;
}

#endif /* not CONFIG_E1000_SPI_GENERIC */

#ifdef CONFIG_CMD_E1000

/* The EEPROM opcodes */
#define SPI_EEPROM_ENABLE_WR    0x06
#define SPI_EEPROM_DISABLE_WR   0x04
#define SPI_EEPROM_WRITE_STATUS 0x01
#define SPI_EEPROM_READ_STATUS  0x05
#define SPI_EEPROM_WRITE_PAGE   0x02
#define SPI_EEPROM_READ_PAGE    0x03

/* The EEPROM status bits */
#define SPI_EEPROM_STATUS_BUSY  0x01
#define SPI_EEPROM_STATUS_WREN  0x02

static int e1000_spi_eeprom_enable_wr(struct e1000_hw *hw, bool intr)
{
        u8 op[] = { SPI_EEPROM_ENABLE_WR };
        e1000_standby_eeprom(hw);
        return e1000_spi_xfer(hw, 8*sizeof(op), op, NULL, intr);
}

/*
 * These have been tested to perform correctly, but they are not used by any
 * of the EEPROM commands at this time.
 */
static __maybe_unused int e1000_spi_eeprom_disable_wr(struct e1000_hw *hw,
                                                      bool intr)
{
        u8 op[] = { SPI_EEPROM_DISABLE_WR };
        e1000_standby_eeprom(hw);
        return e1000_spi_xfer(hw, 8*sizeof(op), op, NULL, intr);
}

static __maybe_unused int e1000_spi_eeprom_write_status(struct e1000_hw *hw,
                                                        u8 status, bool intr)
{
        u8 op[] = { SPI_EEPROM_WRITE_STATUS, status };
        e1000_standby_eeprom(hw);
        return e1000_spi_xfer(hw, 8*sizeof(op), op, NULL, intr);
}

static int e1000_spi_eeprom_read_status(struct e1000_hw *hw, bool intr)
{
        u8 op[] = { SPI_EEPROM_READ_STATUS, 0 };
        e1000_standby_eeprom(hw);
        if (e1000_spi_xfer(hw, 8*sizeof(op), op, op, intr))
                return -1;
        return op[1];
}

static int e1000_spi_eeprom_write_page(struct e1000_hw *hw,
                const void *data, u16 off, u16 len, bool intr)
{
        u8 op[] = {
                SPI_EEPROM_WRITE_PAGE,
                (off >> (hw->eeprom.address_bits - 8)) & 0xff, off & 0xff
        };

        e1000_standby_eeprom(hw);

        if (e1000_spi_xfer(hw, 8 + hw->eeprom.address_bits, op, NULL, intr))
                return -1;
        if (e1000_spi_xfer(hw, len << 3, data, NULL, intr))
                return -1;

        return 0;
}

static int e1000_spi_eeprom_read_page(struct e1000_hw *hw,
                void *data, u16 off, u16 len, bool intr)
{
        u8 op[] = {
                SPI_EEPROM_READ_PAGE,
                (off >> (hw->eeprom.address_bits - 8)) & 0xff, off & 0xff
        };

        e1000_standby_eeprom(hw);

        if (e1000_spi_xfer(hw, 8 + hw->eeprom.address_bits, op, NULL, intr))
                return -1;
        if (e1000_spi_xfer(hw, len << 3, NULL, data, intr))
                return -1;

        return 0;
}

static int e1000_spi_eeprom_poll_ready(struct e1000_hw *hw, bool intr)
{
        int status;
        while ((status = e1000_spi_eeprom_read_status(hw, intr)) >= 0) {
                if (!(status & SPI_EEPROM_STATUS_BUSY))
                        return 0;
        }
        return -1;
}

static int e1000_spi_eeprom_dump(struct e1000_hw *hw,
                void *data, u16 off, unsigned int len, bool intr)
{
        /* Interruptibly wait for the EEPROM to be ready */
        if (e1000_spi_eeprom_poll_ready(hw, intr))
                return -1;

        /* Dump each page in sequence */
        while (len) {
                /* Calculate the data bytes on this page */
                u16 pg_off = off & (hw->eeprom.page_size - 1);
                u16 pg_len = hw->eeprom.page_size - pg_off;
                if (pg_len > len)
                        pg_len = len;

                /* Now dump the page */
                if (e1000_spi_eeprom_read_page(hw, data, off, pg_len, intr))
                        return -1;

                /* Otherwise go on to the next page */
                len  -= pg_len;
                off  += pg_len;
                data += pg_len;
        }

        /* We're done! */
        return 0;
}

static int e1000_spi_eeprom_program(struct e1000_hw *hw,
                const void *data, u16 off, u16 len, bool intr)
{
        /* Program each page in sequence */
        while (len) {
                /* Calculate the data bytes on this page */
                u16 pg_off = off & (hw->eeprom.page_size - 1);
                u16 pg_len = hw->eeprom.page_size - pg_off;
                if (pg_len > len)
                        pg_len = len;

                /* Interruptibly wait for the EEPROM to be ready */
                if (e1000_spi_eeprom_poll_ready(hw, intr))
                        return -1;

                /* Enable write access */
                if (e1000_spi_eeprom_enable_wr(hw, intr))
                        return -1;

                /* Now program the page */
                if (e1000_spi_eeprom_write_page(hw, data, off, pg_len, intr))
                        return -1;

                /* Otherwise go on to the next page */
                len  -= pg_len;
                off  += pg_len;
                data += pg_len;
        }

        /* Wait for the last write to complete */
        if (e1000_spi_eeprom_poll_ready(hw, intr))
                return -1;

        /* We're done! */
        return 0;
}

static int do_e1000_spi_show(cmd_tbl_t *cmdtp, struct e1000_hw *hw,
                int argc, char * const argv[])
{
        unsigned int length = 0;
        u16 i, offset = 0;
        u8 *buffer;
        int err;

        if (argc > 2) {
                cmd_usage(cmdtp);
                return 1;
        }

        /* Parse the offset and length */
        if (argc >= 1)
                offset = simple_strtoul(argv[0], NULL, 0);
        if (argc == 2)
                length = simple_strtoul(argv[1], NULL, 0);
        else if (offset < (hw->eeprom.word_size << 1))
                length = (hw->eeprom.word_size << 1) - offset;

        /* Extra sanity checks */
        if (!length) {
                E1000_ERR(hw, "Requested zero-sized dump!\n");
                return 1;
        }
        if ((0x10000 < length) || (0x10000 - length < offset)) {
                E1000_ERR(hw, "Can't dump past 0xFFFF!\n");
                return 1;
        }

        /* Allocate a buffer to hold stuff */
        buffer = malloc(length);
        if (!buffer) {
                E1000_ERR(hw, "Out of Memory!\n");
                return 1;
        }

        /* Acquire the EEPROM and perform the dump */
        if (e1000_acquire_eeprom(hw)) {
                E1000_ERR(hw, "EEPROM SPI cannot be acquired!\n");
                free(buffer);
                return 1;
        }
        err = e1000_spi_eeprom_dump(hw, buffer, offset, length, true);
        e1000_release_eeprom(hw);
        if (err) {
                E1000_ERR(hw, "Interrupted!\n");
                free(buffer);
                return 1;
        }

        /* Now hexdump the result */
        printf("%s: ===== Intel e1000 EEPROM (0x%04hX - 0x%04hX) =====",
                        hw->name, offset, offset + length - 1);
        for (i = 0; i < length; i++) {
                if ((i & 0xF) == 0)
                        printf("\n%s: %04hX: ", hw->name, offset + i);
                else if ((i & 0xF) == 0x8)
                        printf(" ");
                printf(" %02hx", buffer[i]);
        }
        printf("\n");

        /* Success! */
        free(buffer);
        return 0;
}

static int do_e1000_spi_dump(cmd_tbl_t *cmdtp, struct e1000_hw *hw,
                int argc, char * const argv[])
{
        unsigned int length;
        u16 offset;
        void *dest;

        if (argc != 3) {
                cmd_usage(cmdtp);
                return 1;
        }

        /* Parse the arguments */
        dest = (void *)simple_strtoul(argv[0], NULL, 16);
        offset = simple_strtoul(argv[1], NULL, 0);
        length = simple_strtoul(argv[2], NULL, 0);

        /* Extra sanity checks */
        if (!length) {
                E1000_ERR(hw, "Requested zero-sized dump!\n");
                return 1;
        }
        if ((0x10000 < length) || (0x10000 - length < offset)) {
                E1000_ERR(hw, "Can't dump past 0xFFFF!\n");
                return 1;
        }

        /* Acquire the EEPROM */
        if (e1000_acquire_eeprom(hw)) {
                E1000_ERR(hw, "EEPROM SPI cannot be acquired!\n");
                return 1;
        }

        /* Perform the programming operation */
        if (e1000_spi_eeprom_dump(hw, dest, offset, length, true) < 0) {
                E1000_ERR(hw, "Interrupted!\n");
                e1000_release_eeprom(hw);
                return 1;
        }

        e1000_release_eeprom(hw);
        printf("%s: ===== EEPROM DUMP COMPLETE =====\n", hw->name);
        return 0;
}

static int do_e1000_spi_program(cmd_tbl_t *cmdtp, struct e1000_hw *hw,
                int argc, char * const argv[])
{
        unsigned int length;
        const void *source;
        u16 offset;

        if (argc != 3) {
                cmd_usage(cmdtp);
                return 1;
        }

        /* Parse the arguments */
        source = (const void *)simple_strtoul(argv[0], NULL, 16);
        offset = simple_strtoul(argv[1], NULL, 0);
        length = simple_strtoul(argv[2], NULL, 0);

        /* Acquire the EEPROM */
        if (e1000_acquire_eeprom(hw)) {
                E1000_ERR(hw, "EEPROM SPI cannot be acquired!\n");
                return 1;
        }

        /* Perform the programming operation */
        if (e1000_spi_eeprom_program(hw, source, offset, length, true) < 0) {
                E1000_ERR(hw, "Interrupted!\n");
                e1000_release_eeprom(hw);
                return 1;
        }

        e1000_release_eeprom(hw);
        printf("%s: ===== EEPROM PROGRAMMED =====\n", hw->name);
        return 0;
}

static int do_e1000_spi_checksum(cmd_tbl_t *cmdtp, struct e1000_hw *hw,
                int argc, char * const argv[])
{
        uint16_t i, length, checksum = 0, checksum_reg;
        uint16_t *buffer;
        bool upd;

        if (argc == 0)
                upd = 0;
        else if ((argc == 1) && !strcmp(argv[0], "update"))
                upd = 1;
        else {
                cmd_usage(cmdtp);
                return 1;
        }

        /* Allocate a temporary buffer */
        length = sizeof(uint16_t) * (EEPROM_CHECKSUM_REG + 1);
        buffer = malloc(length);
        if (!buffer) {
                E1000_ERR(hw, "Unable to allocate EEPROM buffer!\n");
                return 1;
        }

        /* Acquire the EEPROM */
        if (e1000_acquire_eeprom(hw)) {
                E1000_ERR(hw, "EEPROM SPI cannot be acquired!\n");
                return 1;
        }

        /* Read the EEPROM */
        if (e1000_spi_eeprom_dump(hw, buffer, 0, length, true) < 0) {
                E1000_ERR(hw, "Interrupted!\n");
                e1000_release_eeprom(hw);
                return 1;
        }

        /* Compute the checksum and read the expected value */
        for (i = 0; i < EEPROM_CHECKSUM_REG; i++)
                checksum += le16_to_cpu(buffer[i]);
        checksum = ((uint16_t)EEPROM_SUM) - checksum;
        checksum_reg = le16_to_cpu(buffer[i]);

        /* Verify it! */
        if (checksum_reg == checksum) {
                printf("%s: INFO: EEPROM checksum is correct! (0x%04hx)\n",
                                hw->name, checksum);
                e1000_release_eeprom(hw);
                return 0;
        }

        /* Hrm, verification failed, print an error */
        E1000_ERR(hw, "EEPROM checksum is incorrect!\n");
        E1000_ERR(hw, "  ...register was 0x%04hx, calculated 0x%04hx\n",
                  checksum_reg, checksum);

        /* If they didn't ask us to update it, just return an error */
        if (!upd) {
                e1000_release_eeprom(hw);
                return 1;
        }

        /* Ok, correct it! */
        printf("%s: Reprogramming the EEPROM checksum...\n", hw->name);
        buffer[i] = cpu_to_le16(checksum);
        if (e1000_spi_eeprom_program(hw, &buffer[i], i * sizeof(uint16_t),
                        sizeof(uint16_t), true)) {
                E1000_ERR(hw, "Interrupted!\n");
                e1000_release_eeprom(hw);
                return 1;
        }

        e1000_release_eeprom(hw);
        return 0;
}

int do_e1000_spi(cmd_tbl_t *cmdtp, struct e1000_hw *hw,
                int argc, char * const argv[])
{
        if (argc < 1) {
                cmd_usage(cmdtp);
                return 1;
        }

        /* Make sure it has an SPI chip */
        if (hw->eeprom.type != e1000_eeprom_spi) {
                E1000_ERR(hw, "No attached SPI EEPROM found (%d)!\n",
                          hw->eeprom.type);
                return 1;
        }

        /* Check the eeprom sub-sub-command arguments */
        if (!strcmp(argv[0], "show"))
                return do_e1000_spi_show(cmdtp, hw, argc - 1, argv + 1);

        if (!strcmp(argv[0], "dump"))
                return do_e1000_spi_dump(cmdtp, hw, argc - 1, argv + 1);

        if (!strcmp(argv[0], "program"))
                return do_e1000_spi_program(cmdtp, hw, argc - 1, argv + 1);

        if (!strcmp(argv[0], "checksum"))
                return do_e1000_spi_checksum(cmdtp, hw, argc - 1, argv + 1);

        cmd_usage(cmdtp);
        return 1;
}

#endif /* not CONFIG_CMD_E1000 */