cregit-Linux how code gets into the kernel

Release 4.7 drivers/scsi/aic7xxx/aic7xxx_93cx6.c

/*
 * Interface for the 93C66/56/46/26/06 serial eeprom parts.
 *
 * Copyright (c) 1995, 1996 Daniel M. Eischen
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: //depot/aic7xxx/aic7xxx/aic7xxx_93cx6.c#19 $
 */

/*
 *   The instruction set of the 93C66/56/46/26/06 chips are as follows:
 *
 *               Start  OP          *
 *     Function   Bit  Code  Address**  Data     Description
 *     -------------------------------------------------------------------
 *     READ        1    10   A5 - A0             Reads data stored in memory,
 *                                               starting at specified address
 *     EWEN        1    00   11XXXX              Write enable must precede
 *                                               all programming modes
 *     ERASE       1    11   A5 - A0             Erase register A5A4A3A2A1A0
 *     WRITE       1    01   A5 - A0   D15 - D0  Writes register
 *     ERAL        1    00   10XXXX              Erase all registers
 *     WRAL        1    00   01XXXX    D15 - D0  Writes to all registers
 *     EWDS        1    00   00XXXX              Disables all programming
 *                                               instructions
 *     *Note: A value of X for address is a don't care condition.
 *    **Note: There are 8 address bits for the 93C56/66 chips unlike
 *            the 93C46/26/06 chips which have 6 address bits.
 *
 *   The 93C46 has a four wire interface: clock, chip select, data in, and
 *   data out.  In order to perform one of the above functions, you need
 *   to enable the chip select for a clock period (typically a minimum of
 *   1 usec, with the clock high and low a minimum of 750 and 250 nsec
 *   respectively).  While the chip select remains high, you can clock in
 *   the instructions (above) starting with the start bit, followed by the
 *   OP code, Address, and Data (if needed).  For the READ instruction, the
 *   requested 16-bit register contents is read from the data out line but
 *   is preceded by an initial zero (leading 0, followed by 16-bits, MSB
 *   first).  The clock cycling from low to high initiates the next data
 *   bit to be sent from the chip.
 */

#ifdef __linux__
#include "aic7xxx_osm.h"
#include "aic7xxx_inline.h"
#include "aic7xxx_93cx6.h"
#else
#include <dev/aic7xxx/aic7xxx_osm.h>
#include <dev/aic7xxx/aic7xxx_inline.h>
#include <dev/aic7xxx/aic7xxx_93cx6.h>
#endif

/*
 * Right now, we only have to read the SEEPROM.  But we make it easier to
 * add other 93Cx6 functions.
 */

struct seeprom_cmd {
  	
uint8_t len;
 	
uint8_t bits[11];
};

/* Short opcodes for the c46 */

static const struct seeprom_cmd seeprom_ewen = {9, {1, 0, 0, 1, 1, 0, 0, 0, 0}};

static const struct seeprom_cmd seeprom_ewds = {9, {1, 0, 0, 0, 0, 0, 0, 0, 0}};

/* Long opcodes for the C56/C66 */

static const struct seeprom_cmd seeprom_long_ewen = {11, {1, 0, 0, 1, 1, 0, 0, 0, 0}};

static const struct seeprom_cmd seeprom_long_ewds = {11, {1, 0, 0, 0, 0, 0, 0, 0, 0}};

/* Common opcodes */

static const struct seeprom_cmd seeprom_write = {3, {1, 0, 1}};

static const struct seeprom_cmd seeprom_read  = {3, {1, 1, 0}};

/*
 * Wait for the SEERDY to go high; about 800 ns.
 */

#define CLOCK_PULSE(sd, rdy)				\
	while ((SEEPROM_STATUS_INB(sd) & rdy) == 0) {   \
                ;  /* Do nothing */			\
        }                                               \
        (void)SEEPROM_INB(sd);	/* Clear clock */

/*
 * Send a START condition and the given command
 */

static void send_seeprom_cmd(struct seeprom_descriptor *sd, const struct seeprom_cmd *cmd) { uint8_t temp; int i = 0; /* Send chip select for one clock cycle. */ temp = sd->sd_MS ^ sd->sd_CS; SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); for (i = 0; i < cmd->len; i++) { if (cmd->bits[i] != 0) temp ^= sd->sd_DO; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); if (cmd->bits[i] != 0) temp ^= sd->sd_DO; } }

Contributors

PersonTokensPropCommitsCommitProp
justin t. gibbsjustin t. gibbs12990.21%133.33%
linus torvaldslinus torvalds139.09%133.33%
denys vlasenkodenys vlasenko10.70%133.33%
Total143100.00%3100.00%

/* * Clear CS put the chip in the reset state, where it can wait for new commands. */
static void reset_seeprom(struct seeprom_descriptor *sd) { uint8_t temp; temp = sd->sd_MS; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); }

Contributors

PersonTokensPropCommitsCommitProp
justin t. gibbsjustin t. gibbs6995.83%150.00%
linus torvaldslinus torvalds34.17%150.00%
Total72100.00%2100.00%

/* * Read the serial EEPROM and returns 1 if successful and 0 if * not successful. */
int ahc_read_seeprom(struct seeprom_descriptor *sd, uint16_t *buf, u_int start_addr, u_int count) { int i = 0; u_int k = 0; uint16_t v; uint8_t temp; /* * Read the requested registers of the seeprom. The loop * will range from 0 to count-1. */ for (k = start_addr; k < count + start_addr; k++) { /* * Now we're ready to send the read command followed by the * address of the 16-bit register we want to read. */ send_seeprom_cmd(sd, &seeprom_read); /* Send the 6 or 8 bit address (MSB first, LSB last). */ temp = sd->sd_MS ^ sd->sd_CS; for (i = (sd->sd_chip - 1); i >= 0; i--) { if ((k & (1 << i)) != 0) temp ^= sd->sd_DO; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); if ((k & (1 << i)) != 0) temp ^= sd->sd_DO; } /* * Now read the 16 bit register. An initial 0 precedes the * register contents which begins with bit 15 (MSB) and ends * with bit 0 (LSB). The initial 0 will be shifted off the * top of our word as we let the loop run from 0 to 16. */ v = 0; for (i = 16; i >= 0; i--) { SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); v <<= 1; if (SEEPROM_DATA_INB(sd) & sd->sd_DI) v |= 1; SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); } buf[k - start_addr] = v; /* Reset the chip select for the next command cycle. */ reset_seeprom(sd); } #ifdef AHC_DUMP_EEPROM printk("\nSerial EEPROM:\n\t"); for (k = 0; k < count; k = k + 1) { if (((k % 8) == 0) && (k != 0)) { printk(KERN_CONT "\n\t"); } printk(KERN_CONT " 0x%x", buf[k]); } printk(KERN_CONT "\n"); #endif return (1); }

Contributors

PersonTokensPropCommitsCommitProp
justin t. gibbsjustin t. gibbs33097.92%150.00%
pekka j enbergpekka j enberg72.08%150.00%
Total337100.00%2100.00%

/* * Write the serial EEPROM and return 1 if successful and 0 if * not successful. */
int ahc_write_seeprom(struct seeprom_descriptor *sd, uint16_t *buf, u_int start_addr, u_int count) { const struct seeprom_cmd *ewen, *ewds; uint16_t v; uint8_t temp; int i, k; /* Place the chip into write-enable mode */ if (sd->sd_chip == C46) { ewen = &seeprom_ewen; ewds = &seeprom_ewds; } else if (sd->sd_chip == C56_66) { ewen = &seeprom_long_ewen; ewds = &seeprom_long_ewds; } else { printk("ahc_write_seeprom: unsupported seeprom type %d\n", sd->sd_chip); return (0); } send_seeprom_cmd(sd, ewen); reset_seeprom(sd); /* Write all requested data out to the seeprom. */ temp = sd->sd_MS ^ sd->sd_CS; for (k = start_addr; k < count + start_addr; k++) { /* Send the write command */ send_seeprom_cmd(sd, &seeprom_write); /* Send the 6 or 8 bit address (MSB first). */ for (i = (sd->sd_chip - 1); i >= 0; i--) { if ((k & (1 << i)) != 0) temp ^= sd->sd_DO; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); if ((k & (1 << i)) != 0) temp ^= sd->sd_DO; } /* Write the 16 bit value, MSB first */ v = buf[k - start_addr]; for (i = 15; i >= 0; i--) { if ((v & (1 << i)) != 0) temp ^= sd->sd_DO; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); if ((v & (1 << i)) != 0) temp ^= sd->sd_DO; } /* Wait for the chip to complete the write */ temp = sd->sd_MS; SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); temp = sd->sd_MS ^ sd->sd_CS; do { SEEPROM_OUTB(sd, temp); CLOCK_PULSE(sd, sd->sd_RDY); SEEPROM_OUTB(sd, temp ^ sd->sd_CK); CLOCK_PULSE(sd, sd->sd_RDY); } while ((SEEPROM_DATA_INB(sd) & sd->sd_DI) == 0); reset_seeprom(sd); } /* Put the chip back into write-protect mode */ send_seeprom_cmd(sd, ewds); reset_seeprom(sd); return (1); }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds26858.52%120.00%
justin t. gibbsjustin t. gibbs12126.42%120.00%
james bottomleyjames bottomley6714.63%120.00%
denys vlasenkodenys vlasenko10.22%120.00%
pekka j enbergpekka j enberg10.22%120.00%
Total458100.00%5100.00%


int ahc_verify_cksum(struct seeprom_config *sc) { int i; int maxaddr; uint32_t checksum; uint16_t *scarray; maxaddr = (sizeof(*sc)/2) - 1; checksum = 0; scarray = (uint16_t *)sc; for (i = 0; i < maxaddr; i++) checksum = checksum + scarray[i]; if (checksum == 0 || (checksum & 0xFFFF) != sc->checksum) { return (0); } else { return(1); } }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds10199.02%150.00%
justin t. gibbsjustin t. gibbs10.98%150.00%
Total102100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
justin t. gibbsjustin t. gibbs74255.75%120.00%
linus torvaldslinus torvalds43232.46%120.00%
james bottomleyjames bottomley14110.59%120.00%
denys vlasenkodenys vlasenko80.60%120.00%
pekka j enbergpekka j enberg80.60%120.00%
Total1331100.00%5100.00%
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