drivers/i2c/rcar_i2c.c - github/trini/u-boot - Gitiles

 /*
  * drivers/i2c/rcar_i2c.c
  *
  * Copyright (C) 2013 Renesas Electronics Corporation
  * Copyright (C) 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
  *
  * SPDX-License-Identifier: GPL-2.0
  */

 #include <common.h>
 #include <i2c.h>
 #include <asm/io.h>

 DECLARE_GLOBAL_DATA_PTR;

 struct rcar_i2c {
 	u32 icscr;
 	u32 icmcr;
 	u32 icssr;
 	u32 icmsr;
 	u32 icsier;
 	u32 icmier;
 	u32 icccr;
 	u32 icsar;
 	u32 icmar;
 	u32 icrxdtxd;
 	u32 icccr2;
 	u32 icmpr;
 	u32 ichpr;
 	u32 iclpr;
 };

 #define MCR_MDBS	0x80	/* non-fifo mode switch	*/
 #define MCR_FSCL	0x40	/* override SCL pin	*/
 #define MCR_FSDA	0x20	/* override SDA pin	*/
 #define MCR_OBPC	0x10	/* override pins	*/
 #define MCR_MIE		0x08	/* master if enable	*/
 #define MCR_TSBE	0x04
 #define MCR_FSB		0x02	/* force stop bit	*/
 #define MCR_ESG		0x01	/* en startbit gen.	*/

 #define MSR_MASK	0x7f
 #define MSR_MNR		0x40	/* nack received	*/
 #define MSR_MAL		0x20	/* arbitration lost	*/
 #define MSR_MST		0x10	/* sent a stop		*/
 #define MSR_MDE		0x08
 #define MSR_MDT		0x04
 #define MSR_MDR		0x02
 #define MSR_MAT		0x01	/* slave addr xfer done	*/

 static const struct rcar_i2c *i2c_dev[CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS] = {
 	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C0_BASE,
 	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C1_BASE,
 	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C2_BASE,
 	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C3_BASE,
 };

 static void rcar_i2c_raw_rw_common(struct rcar_i2c *dev, u8 chip, uint addr)
 {
 	/* set slave address */
 	writel(chip << 1, &dev->icmar);
 	/* set register address */
 	writel(addr, &dev->icrxdtxd);
 	/* clear status */
 	writel(0, &dev->icmsr);
 	/* start master send */
 	writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);

 	while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDE))
 		!= (MSR_MAT | MSR_MDE))
 		udelay(10);

 	/* clear ESG */
 	writel(MCR_MDBS | MCR_MIE, &dev->icmcr);
 	/* start SCLclk */
 	writel(~(MSR_MAT | MSR_MDE), &dev->icmsr);

 	while (!(readl(&dev->icmsr) & MSR_MDE))
 		udelay(10);
 }

 static void rcar_i2c_raw_rw_finish(struct rcar_i2c *dev)
 {
 	while (!(readl(&dev->icmsr) & MSR_MST))
 		udelay(10);

 	writel(0, &dev->icmcr);
 }

 static int
 rcar_i2c_raw_write(struct rcar_i2c *dev, u8 chip, uint addr, u8 *val, int size)
 {
 	rcar_i2c_raw_rw_common(dev, chip, addr);

 	/* set send date */
 	writel(*val, &dev->icrxdtxd);
 	/* start SCLclk */
 	writel(~MSR_MDE, &dev->icmsr);

 	while (!(readl(&dev->icmsr) & MSR_MDE))
 		udelay(10);

 	/* set stop condition */
 	writel(MCR_MDBS | MCR_MIE | MCR_FSB, &dev->icmcr);
 	/* start SCLclk */
 	writel(~MSR_MDE, &dev->icmsr);

 	rcar_i2c_raw_rw_finish(dev);

 	return 0;
 }

 static u8
 rcar_i2c_raw_read(struct rcar_i2c *dev, u8 chip, uint addr)
 {
 	u8 ret;

 	rcar_i2c_raw_rw_common(dev, chip, addr);

 	/* set slave address, receive */
 	writel((chip << 1) | 1, &dev->icmar);
 	/* clear status */
 	writel(0, &dev->icmsr);
 	/* start master receive */
 	writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);

 	while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDR))
 		!= (MSR_MAT | MSR_MDR))
 		udelay(10);

 	/* clear ESG */
 	writel(MCR_MDBS | MCR_MIE, &dev->icmcr);
 	/* prepare stop condition */
 	writel(MCR_MDBS | MCR_MIE | MCR_FSB, &dev->icmcr);
 	/* start SCLclk */
 	writel(~(MSR_MAT | MSR_MDR), &dev->icmsr);

 	while (!(readl(&dev->icmsr) & MSR_MDR))
 		udelay(10);

 	/* get receive data */
 	ret = (u8)readl(&dev->icrxdtxd);
 	/* start SCLclk */
 	writel(~MSR_MDR, &dev->icmsr);

 	rcar_i2c_raw_rw_finish(dev);

 	return ret;
 }

 /*
  * SCL  = iicck / (20 + SCGD * 8 + F[(ticf + tr + intd) * iicck])
  * iicck  : I2C internal clock < 20 MHz
  * ticf : I2C SCL falling time: 35 ns
  * tr   : I2C SCL rising time:  200 ns
  * intd : LSI internal delay:   I2C0: 50 ns I2C1-3: 5
  * F[n] : n rounded up to an integer
  */
 static u32 rcar_clock_gen(int i2c_no, u32 bus_speed)
 {
 	u32 iicck, f, scl, scgd;
 	u32 intd = 5;

 	int bit = 0, cdf_width = 3;
 	for (bit = 0; bit < (1 << cdf_width); bit++) {
 		iicck = CONFIG_HP_CLK_FREQ / (1 + bit);
 		if (iicck < 20000000)
 			break;
 	}

 	if (bit > (1 << cdf_width)) {
 		puts("rcar-i2c: Can not get CDF\n");
 		return 0;
 	}

 	if (i2c_no == 0)
 		intd = 50;

 	f = (35 + 200 + intd) * (iicck / 1000000000);

 	for (scgd = 0; scgd < 0x40; scgd++) {
 		scl = iicck / (20 + (scgd * 8) + f);
 		if (scl <= bus_speed)
 			break;
 	}

 	if (scgd > 0x40) {
 		puts("rcar-i2c: Can not get SDGB\n");
 		return 0;
 	}

 	debug("%s: scl: %d\n", __func__, scl);
 	debug("%s: bit %x\n", __func__, bit);
 	debug("%s: scgd %x\n", __func__, scgd);
 	debug("%s: iccr %x\n", __func__, (scgd << (cdf_width) | bit));

 	return scgd << (cdf_width) | bit;
 }

 static void
 rcar_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
 {
 	struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
 	u32 icccr = 0;

 	/* No i2c support prior to relocation */
 	if (!(gd->flags & GD_FLG_RELOC))
 		return;

 	/*
 	 * reset slave mode.
 	 * slave mode is not used on this driver
 	 */
 	writel(0, &dev->icsier);
 	writel(0, &dev->icsar);
 	writel(0, &dev->icscr);
 	writel(0, &dev->icssr);

 	/* reset master mode */
 	writel(0, &dev->icmier);
 	writel(0, &dev->icmcr);
 	writel(0, &dev->icmsr);
 	writel(0, &dev->icmar);

 	icccr = rcar_clock_gen(adap->hwadapnr, adap->speed);
 	if (icccr == 0)
 		puts("I2C: Init failed\n");
 	else
 		writel(icccr, &dev->icccr);
 }

 static int rcar_i2c_read(struct i2c_adapter *adap, uint8_t chip,
 			uint addr, int alen, u8 *data, int len)
 {
 	struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
 	int i;

 	for (i = 0; i < len; i++)
 		data[i] = rcar_i2c_raw_read(dev, chip, addr + i);

 	return 0;
 }

 static int rcar_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
 			int alen, u8 *data, int len)
 {
 	struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
 	return rcar_i2c_raw_write(dev, chip, addr, data, len);
 }

 static int
 rcar_i2c_probe(struct i2c_adapter *adap, u8 dev)
 {
 	return rcar_i2c_read(adap, dev, 0, 0, NULL, 0);
 }

 static unsigned int rcar_i2c_set_bus_speed(struct i2c_adapter *adap,
 			unsigned int speed)
 {
 	struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
 	u32 icccr;
 	int ret = 0;

 	rcar_i2c_raw_rw_finish(dev);

 	icccr = rcar_clock_gen(adap->hwadapnr, speed);
 	if (icccr == 0) {
 		puts("I2C: Init failed\n");
 		ret = -1;
 	} else {
 		writel(icccr, &dev->icccr);
 	}
 	return ret;
 }

 /*
  * Register RCAR i2c adapters
  */
 U_BOOT_I2C_ADAP_COMPLETE(rcar_0, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
 			 rcar_i2c_write, rcar_i2c_set_bus_speed,
 			 CONFIG_SYS_RCAR_I2C0_SPEED, 0, 0)
 U_BOOT_I2C_ADAP_COMPLETE(rcar_1, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
 			 rcar_i2c_write, rcar_i2c_set_bus_speed,
 			 CONFIG_SYS_RCAR_I2C1_SPEED, 0, 1)
 U_BOOT_I2C_ADAP_COMPLETE(rcar_2, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
 			 rcar_i2c_write, rcar_i2c_set_bus_speed,
 			 CONFIG_SYS_RCAR_I2C2_SPEED, 0, 2)
 U_BOOT_I2C_ADAP_COMPLETE(rcar_3, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
 			 rcar_i2c_write, rcar_i2c_set_bus_speed,
 			 CONFIG_SYS_RCAR_I2C3_SPEED, 0, 3)
	/*
	* drivers/i2c/rcar_i2c.c
	*
	* Copyright (C) 2013 Renesas Electronics Corporation
	* Copyright (C) 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
	*
	* SPDX-License-Identifier: GPL-2.0
	*/

	#include <common.h>
	#include <i2c.h>
	#include <asm/io.h>

	DECLARE_GLOBAL_DATA_PTR;

	struct rcar_i2c {
	u32 icscr;
	u32 icmcr;
	u32 icssr;
	u32 icmsr;
	u32 icsier;
	u32 icmier;
	u32 icccr;
	u32 icsar;
	u32 icmar;
	u32 icrxdtxd;
	u32 icccr2;
	u32 icmpr;
	u32 ichpr;
	u32 iclpr;
	};

	#define MCR_MDBS 0x80 /* non-fifo mode switch */
	#define MCR_FSCL 0x40 /* override SCL pin */
	#define MCR_FSDA 0x20 /* override SDA pin */
	#define MCR_OBPC 0x10 /* override pins */
	#define MCR_MIE 0x08 /* master if enable */
	#define MCR_TSBE 0x04
	#define MCR_FSB 0x02 /* force stop bit */
	#define MCR_ESG 0x01 /* en startbit gen. */

	#define MSR_MASK 0x7f
	#define MSR_MNR 0x40 /* nack received */
	#define MSR_MAL 0x20 /* arbitration lost */
	#define MSR_MST 0x10 /* sent a stop */
	#define MSR_MDE 0x08
	#define MSR_MDT 0x04
	#define MSR_MDR 0x02
	#define MSR_MAT 0x01 /* slave addr xfer done */

	static const struct rcar_i2c *i2c_dev[CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS] = {
	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C0_BASE,
	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C1_BASE,
	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C2_BASE,
	(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C3_BASE,
	};

	static void rcar_i2c_raw_rw_common(struct rcar_i2c *dev, u8 chip, uint addr)
	{
	/* set slave address */
	writel(chip << 1, &dev->icmar);
	/* set register address */
	writel(addr, &dev->icrxdtxd);
	/* clear status */
	writel(0, &dev->icmsr);
	/* start master send */
	writel(MCR_MDBS \| MCR_MIE \| MCR_ESG, &dev->icmcr);

	while ((readl(&dev->icmsr) & (MSR_MAT \| MSR_MDE))
	!= (MSR_MAT \| MSR_MDE))
	udelay(10);

	/* clear ESG */
	writel(MCR_MDBS \| MCR_MIE, &dev->icmcr);
	/* start SCLclk */
	writel(~(MSR_MAT \| MSR_MDE), &dev->icmsr);

	while (!(readl(&dev->icmsr) & MSR_MDE))
	udelay(10);
	}

	static void rcar_i2c_raw_rw_finish(struct rcar_i2c *dev)
	{
	while (!(readl(&dev->icmsr) & MSR_MST))
	udelay(10);

	writel(0, &dev->icmcr);
	}

	static int
	rcar_i2c_raw_write(struct rcar_i2c dev, u8 chip, uint addr, u8 val, int size)
	{
	rcar_i2c_raw_rw_common(dev, chip, addr);

	/* set send date */
	writel(*val, &dev->icrxdtxd);
	/* start SCLclk */
	writel(~MSR_MDE, &dev->icmsr);

	while (!(readl(&dev->icmsr) & MSR_MDE))
	udelay(10);

	/* set stop condition */
	writel(MCR_MDBS \| MCR_MIE \| MCR_FSB, &dev->icmcr);
	/* start SCLclk */
	writel(~MSR_MDE, &dev->icmsr);

	rcar_i2c_raw_rw_finish(dev);

	return 0;
	}

	static u8
	rcar_i2c_raw_read(struct rcar_i2c *dev, u8 chip, uint addr)
	{
	u8 ret;

	rcar_i2c_raw_rw_common(dev, chip, addr);

	/* set slave address, receive */
	writel((chip << 1) \| 1, &dev->icmar);
	/* clear status */
	writel(0, &dev->icmsr);
	/* start master receive */
	writel(MCR_MDBS \| MCR_MIE \| MCR_ESG, &dev->icmcr);

	while ((readl(&dev->icmsr) & (MSR_MAT \| MSR_MDR))
	!= (MSR_MAT \| MSR_MDR))
	udelay(10);

	/* clear ESG */
	writel(MCR_MDBS \| MCR_MIE, &dev->icmcr);
	/* prepare stop condition */
	writel(MCR_MDBS \| MCR_MIE \| MCR_FSB, &dev->icmcr);
	/* start SCLclk */
	writel(~(MSR_MAT \| MSR_MDR), &dev->icmsr);

	while (!(readl(&dev->icmsr) & MSR_MDR))
	udelay(10);

	/* get receive data */
	ret = (u8)readl(&dev->icrxdtxd);
	/* start SCLclk */
	writel(~MSR_MDR, &dev->icmsr);

	rcar_i2c_raw_rw_finish(dev);

	return ret;
	}

	/*
	* SCL = iicck / (20 + SCGD * 8 + F[(ticf + tr + intd) * iicck])
	* iicck : I2C internal clock < 20 MHz
	* ticf : I2C SCL falling time: 35 ns
	* tr : I2C SCL rising time: 200 ns
	* intd : LSI internal delay: I2C0: 50 ns I2C1-3: 5
	* F[n] : n rounded up to an integer
	*/
	static u32 rcar_clock_gen(int i2c_no, u32 bus_speed)
	{
	u32 iicck, f, scl, scgd;
	u32 intd = 5;

	int bit = 0, cdf_width = 3;
	for (bit = 0; bit < (1 << cdf_width); bit++) {
	iicck = CONFIG_HP_CLK_FREQ / (1 + bit);
	if (iicck < 20000000)
	break;
	}

	if (bit > (1 << cdf_width)) {
	puts("rcar-i2c: Can not get CDF\n");
	return 0;
	}

	if (i2c_no == 0)
	intd = 50;

	f = (35 + 200 + intd) * (iicck / 1000000000);

	for (scgd = 0; scgd < 0x40; scgd++) {
	scl = iicck / (20 + (scgd * 8) + f);
	if (scl <= bus_speed)
	break;
	}

	if (scgd > 0x40) {
	puts("rcar-i2c: Can not get SDGB\n");
	return 0;
	}

	debug("%s: scl: %d\n", __func__, scl);
	debug("%s: bit %x\n", __func__, bit);
	debug("%s: scgd %x\n", __func__, scgd);
	debug("%s: iccr %x\n", __func__, (scgd << (cdf_width) \| bit));

	return scgd << (cdf_width) \| bit;
	}

	static void
	rcar_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
	{
	struct rcar_i2c dev = (struct rcar_i2c )i2c_dev[adap->hwadapnr];
	u32 icccr = 0;

	/* No i2c support prior to relocation */
	if (!(gd->flags & GD_FLG_RELOC))
	return;

	/*
	* reset slave mode.
	* slave mode is not used on this driver
	*/
	writel(0, &dev->icsier);
	writel(0, &dev->icsar);
	writel(0, &dev->icscr);
	writel(0, &dev->icssr);

	/* reset master mode */
	writel(0, &dev->icmier);
	writel(0, &dev->icmcr);
	writel(0, &dev->icmsr);
	writel(0, &dev->icmar);

	icccr = rcar_clock_gen(adap->hwadapnr, adap->speed);
	if (icccr == 0)
	puts("I2C: Init failed\n");
	else
	writel(icccr, &dev->icccr);
	}

	static int rcar_i2c_read(struct i2c_adapter *adap, uint8_t chip,
	uint addr, int alen, u8 *data, int len)
	{
	struct rcar_i2c dev = (struct rcar_i2c )i2c_dev[adap->hwadapnr];
	int i;

	for (i = 0; i < len; i++)
	data[i] = rcar_i2c_raw_read(dev, chip, addr + i);

	return 0;
	}

	static int rcar_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
	int alen, u8 *data, int len)
	{
	struct rcar_i2c dev = (struct rcar_i2c )i2c_dev[adap->hwadapnr];
	return rcar_i2c_raw_write(dev, chip, addr, data, len);
	}

	static int
	rcar_i2c_probe(struct i2c_adapter *adap, u8 dev)
	{
	return rcar_i2c_read(adap, dev, 0, 0, NULL, 0);
	}

	static unsigned int rcar_i2c_set_bus_speed(struct i2c_adapter *adap,
	unsigned int speed)
	{
	struct rcar_i2c dev = (struct rcar_i2c )i2c_dev[adap->hwadapnr];
	u32 icccr;
	int ret = 0;

	rcar_i2c_raw_rw_finish(dev);

	icccr = rcar_clock_gen(adap->hwadapnr, speed);
	if (icccr == 0) {
	puts("I2C: Init failed\n");
	ret = -1;
	} else {
	writel(icccr, &dev->icccr);
	}
	return ret;
	}

	/*
	* Register RCAR i2c adapters
	*/
	U_BOOT_I2C_ADAP_COMPLETE(rcar_0, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
	rcar_i2c_write, rcar_i2c_set_bus_speed,
	CONFIG_SYS_RCAR_I2C0_SPEED, 0, 0)
	U_BOOT_I2C_ADAP_COMPLETE(rcar_1, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
	rcar_i2c_write, rcar_i2c_set_bus_speed,
	CONFIG_SYS_RCAR_I2C1_SPEED, 0, 1)
	U_BOOT_I2C_ADAP_COMPLETE(rcar_2, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
	rcar_i2c_write, rcar_i2c_set_bus_speed,
	CONFIG_SYS_RCAR_I2C2_SPEED, 0, 2)
	U_BOOT_I2C_ADAP_COMPLETE(rcar_3, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
	rcar_i2c_write, rcar_i2c_set_bus_speed,
	CONFIG_SYS_RCAR_I2C3_SPEED, 0, 3)