cregit-Linux how code gets into the kernel

Release 4.14 drivers/atm/nicstarmac.c

Directory: drivers/atm
// SPDX-License-Identifier: GPL-2.0
/*
 * this file included by nicstar.c
 */

/*
 * nicstarmac.c
 * Read this ForeRunner's MAC address from eprom/eeprom
 */

#include <linux/kernel.h>


typedef void __iomem *virt_addr_t;


#define CYCLE_DELAY 5

/*
   This was the original definition
#define osp_MicroDelay(microsec) \
    do { int _i = 4*microsec; while (--_i > 0) { __SLOW_DOWN_IO; }} while (0)
*/

#define osp_MicroDelay(microsec) {unsigned long useconds = (microsec); \
                                  udelay((useconds));}
/*
 * The following tables represent the timing diagrams found in
 * the Data Sheet for the Xicor X25020 EEProm.  The #defines below
 * represent the bits in the NICStAR's General Purpose register
 * that must be toggled for the corresponding actions on the EEProm
 * to occur.
 */

/* Write Data To EEProm from SI line on rising edge of CLK */
/* Read Data From EEProm on falling edge of CLK */


#define CS_HIGH		0x0002	
/* Chip select high */

#define CS_LOW		0x0000	
/* Chip select low (active low) */

#define CLK_HIGH	0x0004	
/* Clock high */

#define CLK_LOW		0x0000	
/* Clock low  */

#define SI_HIGH		0x0001	
/* Serial input data high */

#define SI_LOW		0x0000	
/* Serial input data low */

/* Read Status Register = 0000 0101b */
#if 0
static u_int32_t rdsrtab[] = {
        CS_HIGH | CLK_HIGH,
        CS_LOW | CLK_LOW,
        CLK_HIGH,		/* 0 */
	CLK_LOW,
        CLK_HIGH,		/* 0 */
	CLK_LOW,
        CLK_HIGH,		/* 0 */
	CLK_LOW,
        CLK_HIGH,		/* 0 */
	CLK_LOW,
        CLK_HIGH,		/* 0 */
	CLK_LOW | SI_HIGH,
        CLK_HIGH | SI_HIGH,	/* 1 */
	CLK_LOW | SI_LOW,
        CLK_HIGH,		/* 0 */
	CLK_LOW | SI_HIGH,
        CLK_HIGH | SI_HIGH	/* 1 */
};
#endif /*  0  */

/* Read from EEPROM = 0000 0011b */

static u_int32_t readtab[] = {
	/*
           CS_HIGH | CLK_HIGH,
         */
	CS_LOW | CLK_LOW,
	CLK_HIGH,		/* 0 */
	CLK_LOW,
	CLK_HIGH,		/* 0 */
	CLK_LOW,
	CLK_HIGH,		/* 0 */
	CLK_LOW,
	CLK_HIGH,		/* 0 */
	CLK_LOW,
	CLK_HIGH,		/* 0 */
	CLK_LOW,
	CLK_HIGH,		/* 0 */
	CLK_LOW | SI_HIGH,
	CLK_HIGH | SI_HIGH,	/* 1 */
	CLK_LOW | SI_HIGH,
	CLK_HIGH | SI_HIGH	/* 1 */
};

/* Clock to read from/write to the eeprom */

static u_int32_t clocktab[] = {
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW,
	CLK_HIGH,
	CLK_LOW
};


#define NICSTAR_REG_WRITE(bs, reg, val) \
	while ( readl(bs + STAT) & 0x0200 ) ; \
        writel((val),(base)+(reg))

#define NICSTAR_REG_READ(bs, reg) \
	readl((base)+(reg))

#define NICSTAR_REG_GENERAL_PURPOSE GP

/*
 * This routine will clock the Read_Status_reg function into the X2520
 * eeprom, then pull the result from bit 16 of the NicSTaR's General Purpose 
 * register.  
 */
#if 0
u_int32_t nicstar_read_eprom_status(virt_addr_t base)
{
        u_int32_t val;
        u_int32_t rbyte;
        int32_t i, j;

	/* Send read instruction */
	val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;

        for (i = 0; i < ARRAY_SIZE(rdsrtab); i++) {
                NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
                                  (val | rdsrtab[i]));
                osp_MicroDelay(CYCLE_DELAY);
        }

	/* Done sending instruction - now pull data off of bit 16, MSB first */
	/* Data clocked out of eeprom on falling edge of clock */

	rbyte = 0;
        for (i = 7, j = 0; i >= 0; i--) {
                NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
                                  (val | clocktab[j++]));
                rbyte |= (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)
                            & 0x00010000) >> 16) << i);
                NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
                                  (val | clocktab[j++]));
                osp_MicroDelay(CYCLE_DELAY);
        }
        NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);
        osp_MicroDelay(CYCLE_DELAY);
        return rbyte;
}
#endif /*  0  */

/*
 * This routine will clock the Read_data function into the X2520
 * eeprom, followed by the address to read from, through the NicSTaR's General
 * Purpose register.  
 */


static u_int8_t read_eprom_byte(virt_addr_t base, u_int8_t offset) { u_int32_t val = 0; int i, j = 0; u_int8_t tempread = 0; val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0; /* Send READ instruction */ for (i = 0; i < ARRAY_SIZE(readtab); i++) { NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | readtab[i])); osp_MicroDelay(CYCLE_DELAY); } /* Next, we need to send the byte address to read from */ for (i = 7; i >= 0; i--) { NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | clocktab[j++] | ((offset >> i) & 1))); osp_MicroDelay(CYCLE_DELAY); NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | clocktab[j++] | ((offset >> i) & 1))); osp_MicroDelay(CYCLE_DELAY); } j = 0; /* Now, we can read data from the eeprom by clocking it in */ for (i = 7; i >= 0; i--) { NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | clocktab[j++])); osp_MicroDelay(CYCLE_DELAY); tempread |= (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0x00010000) >> 16) << i); NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | clocktab[j++])); osp_MicroDelay(CYCLE_DELAY); } NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2); osp_MicroDelay(CYCLE_DELAY); return tempread; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)25898.47%133.33%
Ahmed S. Darwish31.15%133.33%
Chas Williams10.38%133.33%
Total262100.00%3100.00%


static void nicstar_init_eprom(virt_addr_t base) { u_int32_t val; /* * turn chip select off */ val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0; NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | CS_HIGH | CLK_HIGH)); osp_MicroDelay(CYCLE_DELAY); NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | CS_HIGH | CLK_LOW)); osp_MicroDelay(CYCLE_DELAY); NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | CS_HIGH | CLK_HIGH)); osp_MicroDelay(CYCLE_DELAY); NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, (val | CS_HIGH | CLK_LOW)); osp_MicroDelay(CYCLE_DELAY); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10298.08%133.33%
Chas Williams21.92%266.67%
Total104100.00%3100.00%

/* * This routine will be the interface to the ReadPromByte function * above. */
static void nicstar_read_eprom(virt_addr_t base, u_int8_t prom_offset, u_int8_t * buffer, u_int32_t nbytes) { u_int i; for (i = 0; i < nbytes; i++) { buffer[i] = read_eprom_byte(base, prom_offset); ++prom_offset; osp_MicroDelay(CYCLE_DELAY); } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)5698.25%150.00%
Chas Williams11.75%150.00%
Total57100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)60193.03%114.29%
Chas Williams385.88%457.14%
Ahmed S. Darwish60.93%114.29%
Greg Kroah-Hartman10.15%114.29%
Total646100.00%7100.00%
Directory: drivers/atm
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.