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

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2020
  * Arthur Li, Cortina Access, arthur.li@cortina-access.com.
  */

 #include <common.h>
 #include <i2c.h>
 #include <log.h>
 #include <asm/io.h>
 #include <dm.h>
 #include <mapmem.h>
 #include "i2c-cortina.h"

 static void set_speed(struct i2c_regs *regs, int i2c_spd)
 {
 	union ca_biw_cfg i2c_cfg;

 	i2c_cfg.wrd = readl(&regs->i2c_cfg);
 	i2c_cfg.bf.core_en = 0;
 	writel(i2c_cfg.wrd, &regs->i2c_cfg);

 	switch (i2c_spd) {
 	case IC_SPEED_MODE_FAST_PLUS:
 		i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
 				  (5 * I2C_SPEED_FAST_PLUS_RATE) - 1;
 		break;

 	case IC_SPEED_MODE_STANDARD:
 		i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
 				  (5 * I2C_SPEED_STANDARD_RATE) - 1;
 		break;

 	case IC_SPEED_MODE_FAST:
 	default:
 		i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
 				  (5 * I2C_SPEED_FAST_RATE) - 1;
 		break;
 	}

 	i2c_cfg.bf.core_en = 1;
 	writel(i2c_cfg.wrd, &regs->i2c_cfg);
 }

 static int ca_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 {
 	struct ca_i2c *priv = dev_get_priv(bus);
 	int i2c_spd;

 	if (speed >= I2C_SPEED_FAST_PLUS_RATE) {
 		i2c_spd = IC_SPEED_MODE_FAST_PLUS;
 		priv->speed = I2C_SPEED_FAST_PLUS_RATE;
 	} else if (speed >= I2C_SPEED_FAST_RATE) {
 		i2c_spd = IC_SPEED_MODE_FAST;
 		priv->speed = I2C_SPEED_FAST_RATE;
 	} else {
 		i2c_spd = IC_SPEED_MODE_STANDARD;
 		priv->speed = I2C_SPEED_STANDARD_RATE;
 	}

 	set_speed(priv->regs, i2c_spd);

 	return 0;
 }

 static int ca_i2c_get_bus_speed(struct udevice *bus)
 {
 	struct ca_i2c *priv = dev_get_priv(bus);

 	return priv->speed;
 }

 static void ca_i2c_init(struct i2c_regs *regs)
 {
 	union ca_biw_cfg i2c_cfg;

 	i2c_cfg.wrd = readl(&regs->i2c_cfg);
 	i2c_cfg.bf.core_en = 0;
 	i2c_cfg.bf.biw_soft_reset = 1;
 	writel(i2c_cfg.wrd, &regs->i2c_cfg);
 	mdelay(10);
 	i2c_cfg.bf.biw_soft_reset = 0;
 	writel(i2c_cfg.wrd, &regs->i2c_cfg);

 	set_speed(regs, IC_SPEED_MODE_STANDARD);

 	i2c_cfg.wrd = readl(&regs->i2c_cfg);
 	i2c_cfg.bf.core_en = 1;
 	writel(i2c_cfg.wrd, &regs->i2c_cfg);
 }

 static int i2c_wait_complete(struct i2c_regs *regs)
 {
 	union ca_biw_ctrl i2c_ctrl;
 	unsigned long start_time_bb = get_timer(0);

 	i2c_ctrl.wrd = readl(&regs->i2c_ctrl);

 	while (i2c_ctrl.bf.biwdone == 0) {
 		i2c_ctrl.wrd = readl(&regs->i2c_ctrl);

 		if (get_timer(start_time_bb) >
 		   (unsigned long)(I2C_BYTE_TO_BB)) {
 			printf("%s not done!!!\n", __func__);
 			return -ETIMEDOUT;
 		}
 	}

 	/* Clear done bit */
 	writel(i2c_ctrl.wrd, &regs->i2c_ctrl);

 	return 0;
 }

 static void i2c_setaddress(struct i2c_regs *regs, unsigned int i2c_addr,
 			   int write_read)
 {
 	writel(i2c_addr | write_read, &regs->i2c_txr);

 	writel(BIW_CTRL_START | BIW_CTRL_WRITE,
 	       &regs->i2c_ctrl);

 	i2c_wait_complete(regs);
 }

 static int i2c_wait_for_bus_busy(struct i2c_regs *regs)
 {
 	union ca_biw_ack i2c_ack;
 	unsigned long start_time_bb = get_timer(0);

 	i2c_ack.wrd = readl(&regs->i2c_ack);

 	while (i2c_ack.bf.biw_busy) {
 		i2c_ack.wrd = readl(&regs->i2c_ack);

 		if (get_timer(start_time_bb) >
 		   (unsigned long)(I2C_BYTE_TO_BB)) {
 			printf("%s: timeout!\n", __func__);
 			return -ETIMEDOUT;
 		}
 	}

 	return 0;
 }

 static int i2c_xfer_init(struct i2c_regs *regs, uint8_t chip, uint addr,
 			 int alen, int write_read)
 {
 	int addr_len = alen;

 	if (i2c_wait_for_bus_busy(regs))
 		return 1;

 	/* First cycle must write addr + offset */
 	chip = ((chip & 0x7F) << 1);
 	if (alen == 0 && write_read == I2C_CMD_RD)
 		i2c_setaddress(regs, chip, I2C_CMD_RD);
 	else
 		i2c_setaddress(regs, chip, I2C_CMD_WT);

 	while (alen) {
 		alen--;
 		writel(addr, &regs->i2c_txr);
 		if (write_read == I2C_CMD_RD)
 			writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
 			       &regs->i2c_ctrl);
 		else
 			writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);
 		i2c_wait_complete(regs);
 	}

 	/* Send address again with Read flag if it's read command */
 	if (write_read == I2C_CMD_RD && addr_len > 0)
 		i2c_setaddress(regs, chip, I2C_CMD_RD);

 	return 0;
 }

 static int i2c_xfer_finish(struct i2c_regs *regs)
 {
 	/* Dummy read makes bus free */
 	writel(BIW_CTRL_READ | BIW_CTRL_STOP, &regs->i2c_ctrl);
 	i2c_wait_complete(regs);

 	if (i2c_wait_for_bus_busy(regs)) {
 		printf("Timed out waiting for bus\n");
 		return -ETIMEDOUT;
 	}

 	return 0;
 }

 static int ca_i2c_read(struct i2c_regs *regs, uint8_t chip, uint addr,
 		       int alen, uint8_t *buffer, int len)
 {
 	unsigned long start_time_rx;
 	int rc = 0;

 	rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_RD);
 	if (rc)
 		return rc;

 	start_time_rx = get_timer(0);
 	while (len) {
 		/* ACK_IN is ack value to send during read.
 		 * ack high only on the very last byte!
 		 */
 		if (len == 1)
 			writel(BIW_CTRL_READ | BIW_CTRL_ACK_IN | BIW_CTRL_STOP,
 			       &regs->i2c_ctrl);
 		else
 			writel(BIW_CTRL_READ, &regs->i2c_ctrl);

 		rc = i2c_wait_complete(regs);
 		udelay(1);

 		if (rc == 0) {
 			*buffer++ =
 				(uchar) readl(&regs->i2c_rxr);
 			len--;
 			start_time_rx = get_timer(0);

 		} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
 			return -ETIMEDOUT;
 		}
 	}
 	i2c_xfer_finish(regs);
 	return rc;
 }

 static int ca_i2c_write(struct i2c_regs *regs, uint8_t chip, uint addr,
 			int alen, uint8_t *buffer, int len)
 {
 	int rc, nb = len;
 	unsigned long start_time_tx;

 	rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_WT);
 	if (rc)
 		return rc;

 	start_time_tx = get_timer(0);
 	while (len) {
 		writel(*buffer, &regs->i2c_txr);
 		if (len == 1)
 			writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
 			       &regs->i2c_ctrl);
 		else
 			writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);

 		rc = i2c_wait_complete(regs);

 		if (rc == 0) {
 			len--;
 			buffer++;
 			start_time_tx = get_timer(0);
 		} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
 			return -ETIMEDOUT;
 		}
 	}

 	return 0;
 }

 static int ca_i2c_probe_chip(struct udevice *bus, uint chip_addr,
 			     uint chip_flags)
 {
 	struct ca_i2c *priv = dev_get_priv(bus);
 	int ret;
 	u32 tmp;

 	/* Try to read the first location of the chip */
 	ret = ca_i2c_read(priv->regs, chip_addr, 0, 1, (uchar *)&tmp, 1);
 	if (ret)
 		ca_i2c_init(priv->regs);

 	return ret;
 }

 static int ca_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
 {
 	struct ca_i2c *priv = dev_get_priv(bus);
 	int ret;

 	debug("i2c_xfer: %d messages\n", nmsgs);
 	for (; nmsgs > 0; nmsgs--, msg++) {
 		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
 		if (msg->flags & I2C_M_RD)
 			ret = ca_i2c_read(priv->regs, msg->addr, 0, 0,
 					  msg->buf, msg->len);
 		else
 			ret = ca_i2c_write(priv->regs, msg->addr, 0, 0,
 					   msg->buf, msg->len);

 		if (ret) {
 			printf("i2c_xfer: %s error\n",
 			       msg->flags & I2C_M_RD ? "read" : "write");
 			return ret;
 		}
 	}

 	return 0;
 }

 static const struct dm_i2c_ops ca_i2c_ops = {
 	.xfer		= ca_i2c_xfer,
 	.probe_chip	= ca_i2c_probe_chip,
 	.set_bus_speed	= ca_i2c_set_bus_speed,
 	.get_bus_speed	= ca_i2c_get_bus_speed,
 };

 static const struct udevice_id ca_i2c_ids[] = {
 	{ .compatible = "cortina,ca-i2c", },
 	{ }
 };

 static int ca_i2c_probe(struct udevice *bus)
 {
 	struct ca_i2c *priv = dev_get_priv(bus);

 	ca_i2c_init(priv->regs);

 	return 0;
 }

 static int ca_i2c_of_to_plat(struct udevice *bus)
 {
 	struct ca_i2c *priv = dev_get_priv(bus);

 	priv->regs = map_sysmem(dev_read_addr(bus), sizeof(struct i2c_regs));
 	if (!priv->regs) {
 		printf("I2C: base address is invalid\n");
 		return -EINVAL;
 	}

 	return 0;
 }

 U_BOOT_DRIVER(i2c_cortina) = {
 	.name	= "i2c_cortina",
 	.id	= UCLASS_I2C,
 	.of_match = ca_i2c_ids,
 	.of_to_plat = ca_i2c_of_to_plat,
 	.probe	= ca_i2c_probe,
 	.priv_auto	= sizeof(struct ca_i2c),
 	.ops	= &ca_i2c_ops,
 	.flags  = DM_FLAG_PRE_RELOC,
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* (C) Copyright 2020
	* Arthur Li, Cortina Access, arthur.li@cortina-access.com.
	*/

	#include <common.h>
	#include <i2c.h>
	#include <log.h>
	#include <asm/io.h>
	#include <dm.h>
	#include <mapmem.h>
	#include "i2c-cortina.h"

	static void set_speed(struct i2c_regs *regs, int i2c_spd)
	{
	union ca_biw_cfg i2c_cfg;

	i2c_cfg.wrd = readl(&regs->i2c_cfg);
	i2c_cfg.bf.core_en = 0;
	writel(i2c_cfg.wrd, &regs->i2c_cfg);

	switch (i2c_spd) {
	case IC_SPEED_MODE_FAST_PLUS:
	i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
	(5 * I2C_SPEED_FAST_PLUS_RATE) - 1;
	break;

	case IC_SPEED_MODE_STANDARD:
	i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
	(5 * I2C_SPEED_STANDARD_RATE) - 1;
	break;

	case IC_SPEED_MODE_FAST:
	default:
	i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
	(5 * I2C_SPEED_FAST_RATE) - 1;
	break;
	}

	i2c_cfg.bf.core_en = 1;
	writel(i2c_cfg.wrd, &regs->i2c_cfg);
	}

	static int ca_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
	{
	struct ca_i2c *priv = dev_get_priv(bus);
	int i2c_spd;

	if (speed >= I2C_SPEED_FAST_PLUS_RATE) {
	i2c_spd = IC_SPEED_MODE_FAST_PLUS;
	priv->speed = I2C_SPEED_FAST_PLUS_RATE;
	} else if (speed >= I2C_SPEED_FAST_RATE) {
	i2c_spd = IC_SPEED_MODE_FAST;
	priv->speed = I2C_SPEED_FAST_RATE;
	} else {
	i2c_spd = IC_SPEED_MODE_STANDARD;
	priv->speed = I2C_SPEED_STANDARD_RATE;
	}

	set_speed(priv->regs, i2c_spd);

	return 0;
	}

	static int ca_i2c_get_bus_speed(struct udevice *bus)
	{
	struct ca_i2c *priv = dev_get_priv(bus);

	return priv->speed;
	}

	static void ca_i2c_init(struct i2c_regs *regs)
	{
	union ca_biw_cfg i2c_cfg;

	i2c_cfg.wrd = readl(&regs->i2c_cfg);
	i2c_cfg.bf.core_en = 0;
	i2c_cfg.bf.biw_soft_reset = 1;
	writel(i2c_cfg.wrd, &regs->i2c_cfg);
	mdelay(10);
	i2c_cfg.bf.biw_soft_reset = 0;
	writel(i2c_cfg.wrd, &regs->i2c_cfg);

	set_speed(regs, IC_SPEED_MODE_STANDARD);

	i2c_cfg.wrd = readl(&regs->i2c_cfg);
	i2c_cfg.bf.core_en = 1;
	writel(i2c_cfg.wrd, &regs->i2c_cfg);
	}

	static int i2c_wait_complete(struct i2c_regs *regs)
	{
	union ca_biw_ctrl i2c_ctrl;
	unsigned long start_time_bb = get_timer(0);

	i2c_ctrl.wrd = readl(&regs->i2c_ctrl);

	while (i2c_ctrl.bf.biwdone == 0) {
	i2c_ctrl.wrd = readl(&regs->i2c_ctrl);

	if (get_timer(start_time_bb) >
	(unsigned long)(I2C_BYTE_TO_BB)) {
	printf("%s not done!!!\n", __func__);
	return -ETIMEDOUT;
	}
	}

	/* Clear done bit */
	writel(i2c_ctrl.wrd, &regs->i2c_ctrl);

	return 0;
	}

	static void i2c_setaddress(struct i2c_regs *regs, unsigned int i2c_addr,
	int write_read)
	{
	writel(i2c_addr \| write_read, &regs->i2c_txr);

	writel(BIW_CTRL_START \| BIW_CTRL_WRITE,
	&regs->i2c_ctrl);

	i2c_wait_complete(regs);
	}

	static int i2c_wait_for_bus_busy(struct i2c_regs *regs)
	{
	union ca_biw_ack i2c_ack;
	unsigned long start_time_bb = get_timer(0);

	i2c_ack.wrd = readl(&regs->i2c_ack);

	while (i2c_ack.bf.biw_busy) {
	i2c_ack.wrd = readl(&regs->i2c_ack);

	if (get_timer(start_time_bb) >
	(unsigned long)(I2C_BYTE_TO_BB)) {
	printf("%s: timeout!\n", __func__);
	return -ETIMEDOUT;
	}
	}

	return 0;
	}

	static int i2c_xfer_init(struct i2c_regs *regs, uint8_t chip, uint addr,
	int alen, int write_read)
	{
	int addr_len = alen;

	if (i2c_wait_for_bus_busy(regs))
	return 1;

	/* First cycle must write addr + offset */
	chip = ((chip & 0x7F) << 1);
	if (alen == 0 && write_read == I2C_CMD_RD)
	i2c_setaddress(regs, chip, I2C_CMD_RD);
	else
	i2c_setaddress(regs, chip, I2C_CMD_WT);

	while (alen) {
	alen--;
	writel(addr, &regs->i2c_txr);
	if (write_read == I2C_CMD_RD)
	writel(BIW_CTRL_WRITE \| BIW_CTRL_STOP,
	&regs->i2c_ctrl);
	else
	writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);
	i2c_wait_complete(regs);
	}

	/* Send address again with Read flag if it's read command */
	if (write_read == I2C_CMD_RD && addr_len > 0)
	i2c_setaddress(regs, chip, I2C_CMD_RD);

	return 0;
	}

	static int i2c_xfer_finish(struct i2c_regs *regs)
	{
	/* Dummy read makes bus free */
	writel(BIW_CTRL_READ \| BIW_CTRL_STOP, &regs->i2c_ctrl);
	i2c_wait_complete(regs);

	if (i2c_wait_for_bus_busy(regs)) {
	printf("Timed out waiting for bus\n");
	return -ETIMEDOUT;
	}

	return 0;
	}

	static int ca_i2c_read(struct i2c_regs *regs, uint8_t chip, uint addr,
	int alen, uint8_t *buffer, int len)
	{
	unsigned long start_time_rx;
	int rc = 0;

	rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_RD);
	if (rc)
	return rc;

	start_time_rx = get_timer(0);
	while (len) {
	/* ACK_IN is ack value to send during read.
	* ack high only on the very last byte!
	*/
	if (len == 1)
	writel(BIW_CTRL_READ \| BIW_CTRL_ACK_IN \| BIW_CTRL_STOP,
	&regs->i2c_ctrl);
	else
	writel(BIW_CTRL_READ, &regs->i2c_ctrl);

	rc = i2c_wait_complete(regs);
	udelay(1);

	if (rc == 0) {
	*buffer++ =
	(uchar) readl(&regs->i2c_rxr);
	len--;
	start_time_rx = get_timer(0);

	} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
	return -ETIMEDOUT;
	}
	}
	i2c_xfer_finish(regs);
	return rc;
	}

	static int ca_i2c_write(struct i2c_regs *regs, uint8_t chip, uint addr,
	int alen, uint8_t *buffer, int len)
	{
	int rc, nb = len;
	unsigned long start_time_tx;

	rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_WT);
	if (rc)
	return rc;

	start_time_tx = get_timer(0);
	while (len) {
	writel(*buffer, &regs->i2c_txr);
	if (len == 1)
	writel(BIW_CTRL_WRITE \| BIW_CTRL_STOP,
	&regs->i2c_ctrl);
	else
	writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);

	rc = i2c_wait_complete(regs);

	if (rc == 0) {
	len--;
	buffer++;
	start_time_tx = get_timer(0);
	} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
	return -ETIMEDOUT;
	}
	}

	return 0;
	}

	static int ca_i2c_probe_chip(struct udevice *bus, uint chip_addr,
	uint chip_flags)
	{
	struct ca_i2c *priv = dev_get_priv(bus);
	int ret;
	u32 tmp;

	/* Try to read the first location of the chip */
	ret = ca_i2c_read(priv->regs, chip_addr, 0, 1, (uchar *)&tmp, 1);
	if (ret)
	ca_i2c_init(priv->regs);

	return ret;
	}

	static int ca_i2c_xfer(struct udevice bus, struct i2c_msg msg, int nmsgs)
	{
	struct ca_i2c *priv = dev_get_priv(bus);
	int ret;

	debug("i2c_xfer: %d messages\n", nmsgs);
	for (; nmsgs > 0; nmsgs--, msg++) {
	debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
	if (msg->flags & I2C_M_RD)
	ret = ca_i2c_read(priv->regs, msg->addr, 0, 0,
	msg->buf, msg->len);
	else
	ret = ca_i2c_write(priv->regs, msg->addr, 0, 0,
	msg->buf, msg->len);

	if (ret) {
	printf("i2c_xfer: %s error\n",
	msg->flags & I2C_M_RD ? "read" : "write");
	return ret;
	}
	}

	return 0;
	}

	static const struct dm_i2c_ops ca_i2c_ops = {
	.xfer = ca_i2c_xfer,
	.probe_chip = ca_i2c_probe_chip,
	.set_bus_speed = ca_i2c_set_bus_speed,
	.get_bus_speed = ca_i2c_get_bus_speed,
	};

	static const struct udevice_id ca_i2c_ids[] = {
	{ .compatible = "cortina,ca-i2c", },
	{ }
	};

	static int ca_i2c_probe(struct udevice *bus)
	{
	struct ca_i2c *priv = dev_get_priv(bus);

	ca_i2c_init(priv->regs);

	return 0;
	}

	static int ca_i2c_of_to_plat(struct udevice *bus)
	{
	struct ca_i2c *priv = dev_get_priv(bus);

	priv->regs = map_sysmem(dev_read_addr(bus), sizeof(struct i2c_regs));
	if (!priv->regs) {
	printf("I2C: base address is invalid\n");
	return -EINVAL;
	}

	return 0;
	}

	U_BOOT_DRIVER(i2c_cortina) = {
	.name = "i2c_cortina",
	.id = UCLASS_I2C,
	.of_match = ca_i2c_ids,
	.of_to_plat = ca_i2c_of_to_plat,
	.probe = ca_i2c_probe,
	.priv_auto = sizeof(struct ca_i2c),
	.ops = &ca_i2c_ops,
	.flags = DM_FLAG_PRE_RELOC,
	};