diff options
Diffstat (limited to 'drivers/i2c/sh_sh7734_i2c.c')
| -rw-r--r-- | drivers/i2c/sh_sh7734_i2c.c | 387 | 
1 files changed, 387 insertions, 0 deletions
| diff --git a/drivers/i2c/sh_sh7734_i2c.c b/drivers/i2c/sh_sh7734_i2c.c new file mode 100644 index 000000000..9da173d31 --- /dev/null +++ b/drivers/i2c/sh_sh7734_i2c.c @@ -0,0 +1,387 @@ +/* + * Copyright (C) 2012 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> + * Copyright (C) 2012 Renesas Solutions Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <i2c.h> +#include <asm/io.h> + +struct sh_i2c { +	u8 iccr1; +	u8 iccr2; +	u8 icmr; +	u8 icier; +	u8 icsr; +	u8 sar; +	u8 icdrt; +	u8 icdrr; +	u8 nf2cyc; +	u8 __pad0; +	u8 __pad1; +}; + +static struct sh_i2c *base; +static u8 iccr1_cks, nf2cyc; + +/* ICCR1 */ +#define SH_I2C_ICCR1_ICE	(1 << 7) +#define SH_I2C_ICCR1_RCVD	(1 << 6) +#define SH_I2C_ICCR1_MST	(1 << 5) +#define SH_I2C_ICCR1_TRS	(1 << 4) +#define SH_I2C_ICCR1_MTRS	\ +	(SH_I2C_ICCR1_MST | SH_I2C_ICCR1_TRS) + +/* ICCR1 */ +#define SH_I2C_ICCR2_BBSY	(1 << 7) +#define SH_I2C_ICCR2_SCP	(1 << 6) +#define SH_I2C_ICCR2_SDAO	(1 << 5) +#define SH_I2C_ICCR2_SDAOP	(1 << 4) +#define SH_I2C_ICCR2_SCLO	(1 << 3) +#define SH_I2C_ICCR2_IICRST	(1 << 1) + +#define SH_I2C_ICIER_TIE	(1 << 7) +#define SH_I2C_ICIER_TEIE	(1 << 6) +#define SH_I2C_ICIER_RIE	(1 << 5) +#define SH_I2C_ICIER_NAKIE	(1 << 4) +#define SH_I2C_ICIER_STIE	(1 << 3) +#define SH_I2C_ICIER_ACKE	(1 << 2) +#define SH_I2C_ICIER_ACKBR	(1 << 1) +#define SH_I2C_ICIER_ACKBT	(1 << 0) + +#define SH_I2C_ICSR_TDRE	(1 << 7) +#define SH_I2C_ICSR_TEND	(1 << 6) +#define SH_I2C_ICSR_RDRF	(1 << 5) +#define SH_I2C_ICSR_NACKF	(1 << 4) +#define SH_I2C_ICSR_STOP	(1 << 3) +#define SH_I2C_ICSR_ALOVE	(1 << 2) +#define SH_I2C_ICSR_AAS		(1 << 1) +#define SH_I2C_ICSR_ADZ		(1 << 0) + +#define IRQ_WAIT 1000 + +static void sh_i2c_send_stop(struct sh_i2c *base) +{ +	clrbits_8(&base->iccr2, SH_I2C_ICCR2_BBSY | SH_I2C_ICCR2_SCP); +} + +static int check_icsr_bits(struct sh_i2c *base, u8 bits) +{ +	int i; + +	for (i = 0; i < IRQ_WAIT; i++) { +		if (bits & readb(&base->icsr)) +			return 0; +		udelay(10); +	} + +	return 1; +} + +static int check_stop(struct sh_i2c *base) +{ +	int ret = check_icsr_bits(base, SH_I2C_ICSR_STOP); +	clrbits_8(&base->icsr, SH_I2C_ICSR_STOP); + +	return ret; +} + +static int check_tend(struct sh_i2c *base, int stop) +{ +	int ret = check_icsr_bits(base, SH_I2C_ICSR_TEND); + +	if (stop) { +		clrbits_8(&base->icsr, SH_I2C_ICSR_STOP); +		sh_i2c_send_stop(base); +	} + +	clrbits_8(&base->icsr, SH_I2C_ICSR_TEND); +	return ret; +} + +static int check_tdre(struct sh_i2c *base) +{ +	return check_icsr_bits(base, SH_I2C_ICSR_TDRE); +} + +static int check_rdrf(struct sh_i2c *base) +{ +	return check_icsr_bits(base, SH_I2C_ICSR_RDRF); +} + +static int check_bbsy(struct sh_i2c *base) +{ +	int i; + +	for (i = 0 ; i < IRQ_WAIT ; i++) { +		if (!(SH_I2C_ICCR2_BBSY & readb(&base->iccr2))) +			return 0; +		udelay(10); +	} +	return 1; +} + +static int check_ackbr(struct sh_i2c *base) +{ +	int i; + +	for (i = 0 ; i < IRQ_WAIT ; i++) { +		if (!(SH_I2C_ICIER_ACKBR & readb(&base->icier))) +			return 0; +		udelay(10); +	} + +	return 1; +} + +static void sh_i2c_reset(struct sh_i2c *base) +{ +	setbits_8(&base->iccr2, SH_I2C_ICCR2_IICRST); + +	udelay(100); + +	clrbits_8(&base->iccr2, SH_I2C_ICCR2_IICRST); +} + +static int i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg) +{ +	if (check_bbsy(base)) { +		puts("i2c bus busy\n"); +		goto fail; +	} + +	setbits_8(&base->iccr1, SH_I2C_ICCR1_MTRS); +	clrsetbits_8(&base->iccr2, SH_I2C_ICCR2_SCP, SH_I2C_ICCR2_BBSY); + +	writeb((id << 1), &base->icdrt); + +	if (check_tend(base, 0)) { +		puts("TEND check fail...\n"); +		goto fail; +	} + +	if (check_ackbr(base)) { +		check_tend(base, 0); +		sh_i2c_send_stop(base); +		goto fail; +	} + +	writeb(reg, &base->icdrt); + +	if (check_tdre(base)) { +		puts("TDRE check fail...\n"); +		goto fail; +	} + +	if (check_tend(base, 0)) { +		puts("TEND check fail...\n"); +		goto fail; +	} + +	return 0; +fail: + +	return 1; +} + +static int +i2c_raw_write(struct sh_i2c *base, u8 id, u8 reg, u8 *val, int size) +{ +	int i; + +	if (i2c_set_addr(base, id, reg)) { +		puts("Fail set slave address\n"); +		return 1; +	} + +	for (i = 0; i < size; i++) { +		writeb(val[i], &base->icdrt); +		check_tdre(base); +	} + +	check_tend(base, 1); +	check_stop(base); + +	udelay(100); + +	clrbits_8(&base->iccr1, SH_I2C_ICCR1_MTRS); +	clrbits_8(&base->icsr, SH_I2C_ICSR_TDRE); +	sh_i2c_reset(base); + +	return 0; +} + +static u8 i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg) +{ +	u8 ret = 0; + +	if (i2c_set_addr(base, id, reg)) { +		puts("Fail set slave address\n"); +		goto fail; +	} + +	clrsetbits_8(&base->iccr2, SH_I2C_ICCR2_SCP, SH_I2C_ICCR2_BBSY); +	writeb((id << 1) | 1, &base->icdrt); + +	if (check_tend(base, 0)) +		puts("TDRE check fail...\n"); + +	clrsetbits_8(&base->iccr1, SH_I2C_ICCR1_TRS, SH_I2C_ICCR1_MST); +	clrbits_8(&base->icsr, SH_I2C_ICSR_TDRE); +	setbits_8(&base->icier, SH_I2C_ICIER_ACKBT); +	setbits_8(&base->iccr1, SH_I2C_ICCR1_RCVD); + +	/* read data (dummy) */ +	ret = readb(&base->icdrr); + +	if (check_rdrf(base)) { +		puts("check RDRF error\n"); +		goto fail; +	} + +	clrbits_8(&base->icsr, SH_I2C_ICSR_STOP); +	udelay(1000); + +	sh_i2c_send_stop(base); + +	if (check_stop(base)) { +		puts("check STOP error\n"); +		goto fail; +	} + +	clrbits_8(&base->iccr1, SH_I2C_ICCR1_MTRS); +	clrbits_8(&base->icsr, SH_I2C_ICSR_TDRE); + +	/* data read */ +	ret = readb(&base->icdrr); + +fail: +	clrbits_8(&base->iccr1, SH_I2C_ICCR1_RCVD); + +	return ret; +} + +#ifdef CONFIG_I2C_MULTI_BUS +static unsigned int current_bus; + +/** + * i2c_set_bus_num - change active I2C bus + *	@bus: bus index, zero based + *	@returns: 0 on success, non-0 on failure + */ +int i2c_set_bus_num(unsigned int bus) +{ +	switch (bus) { +	case 0: +		base = (void *)CONFIG_SH_I2C_BASE0; +		break; +	case 1: +		base = (void *)CONFIG_SH_I2C_BASE1; +		break; +	default: +		printf("Bad bus: %d\n", bus); +		return -1; +	} + +	current_bus = bus; + +	return 0; +} + +/** + * i2c_get_bus_num - returns index of active I2C bus + */ +unsigned int i2c_get_bus_num(void) +{ +	return current_bus; +} +#endif + +void i2c_init(int speed, int slaveaddr) +{ +#ifdef CONFIG_I2C_MULTI_BUS +	current_bus = 0; +#endif +	base = (struct sh_i2c *)CONFIG_SH_I2C_BASE0; + +	if (speed == 400000) +		iccr1_cks = 0x07; +	else +		iccr1_cks = 0x0F; + +	nf2cyc = 1; + +	/* Reset */ +	sh_i2c_reset(base); + +	/* ICE enable and set clock */ +	writeb(SH_I2C_ICCR1_ICE | iccr1_cks, &base->iccr1); +	writeb(nf2cyc, &base->nf2cyc); +} + +/* + * i2c_read: - Read multiple bytes from an i2c device + * + * The higher level routines take into account that this function is only + * called with len < page length of the device (see configuration file) + * + * @chip:   address of the chip which is to be read + * @addr:   i2c data address within the chip + * @alen:   length of the i2c data address (1..2 bytes) + * @buffer: where to write the data + * @len:    how much byte do we want to read + * @return: 0 in case of success + */ +int i2c_read(u8 chip, u32 addr, int alen, u8 *buffer, int len) +{ +	int i = 0; +	for (i = 0; i < len; i++) +		buffer[i] = i2c_raw_read(base, chip, addr + i); + +	return 0; +} + +/* + * i2c_write: -  Write multiple bytes to an i2c device + * + * The higher level routines take into account that this function is only + * called with len < page length of the device (see configuration file) + * + * @chip:   address of the chip which is to be written + * @addr:   i2c data address within the chip + * @alen:   length of the i2c data address (1..2 bytes) + * @buffer: where to find the data to be written + * @len:    how much byte do we want to read + * @return: 0 in case of success + */ +int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len) +{ +	return i2c_raw_write(base, chip, addr, buffer, len); +} + +/* + * i2c_probe: - Test if a chip answers for a given i2c address + * + * @chip:   address of the chip which is searched for + * @return: 0 if a chip was found, -1 otherwhise + */ +int i2c_probe(u8 chip) +{ +	u8 byte; +	return i2c_read(chip, 0, 0, &byte, 1); +} |