[mirror_ubuntu-bionic-kernel.git] / drivers / i2c / busses / i2c-xlp9xx.c

/*
 * Copyright (c) 2003-2015 Broadcom Corporation
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>

#define XLP9XX_I2C_DIV			0x0
#define XLP9XX_I2C_CTRL			0x1
#define XLP9XX_I2C_CMD			0x2
#define XLP9XX_I2C_STATUS		0x3
#define XLP9XX_I2C_MTXFIFO		0x4
#define XLP9XX_I2C_MRXFIFO		0x5
#define XLP9XX_I2C_MFIFOCTRL		0x6
#define XLP9XX_I2C_STXFIFO		0x7
#define XLP9XX_I2C_SRXFIFO		0x8
#define XLP9XX_I2C_SFIFOCTRL		0x9
#define XLP9XX_I2C_SLAVEADDR		0xA
#define XLP9XX_I2C_OWNADDR		0xB
#define XLP9XX_I2C_FIFOWCNT		0xC
#define XLP9XX_I2C_INTEN		0xD
#define XLP9XX_I2C_INTST		0xE
#define XLP9XX_I2C_WAITCNT		0xF
#define XLP9XX_I2C_TIMEOUT		0X10
#define XLP9XX_I2C_GENCALLADDR		0x11

#define XLP9XX_I2C_STATUS_BUSY		BIT(0)

#define XLP9XX_I2C_CMD_START		BIT(7)
#define XLP9XX_I2C_CMD_STOP		BIT(6)
#define XLP9XX_I2C_CMD_READ		BIT(5)
#define XLP9XX_I2C_CMD_WRITE		BIT(4)
#define XLP9XX_I2C_CMD_ACK		BIT(3)

#define XLP9XX_I2C_CTRL_MCTLEN_SHIFT	16
#define XLP9XX_I2C_CTRL_MCTLEN_MASK	0xffff0000
#define XLP9XX_I2C_CTRL_RST		BIT(8)
#define XLP9XX_I2C_CTRL_EN		BIT(6)
#define XLP9XX_I2C_CTRL_MASTER		BIT(4)
#define XLP9XX_I2C_CTRL_FIFORD		BIT(1)
#define XLP9XX_I2C_CTRL_ADDMODE		BIT(0)

#define XLP9XX_I2C_INTEN_NACKADDR	BIT(25)
#define XLP9XX_I2C_INTEN_SADDR		BIT(13)
#define XLP9XX_I2C_INTEN_DATADONE	BIT(12)
#define XLP9XX_I2C_INTEN_ARLOST		BIT(11)
#define XLP9XX_I2C_INTEN_MFIFOFULL	BIT(4)
#define XLP9XX_I2C_INTEN_MFIFOEMTY	BIT(3)
#define XLP9XX_I2C_INTEN_MFIFOHI	BIT(2)
#define XLP9XX_I2C_INTEN_BUSERR		BIT(0)

#define XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT		8
#define XLP9XX_I2C_MFIFOCTRL_LOTH_SHIFT		0
#define XLP9XX_I2C_MFIFOCTRL_RST		BIT(16)

#define XLP9XX_I2C_SLAVEADDR_RW			BIT(0)
#define XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT		1

#define XLP9XX_I2C_IP_CLK_FREQ		133000000UL
#define XLP9XX_I2C_DEFAULT_FREQ		100000
#define XLP9XX_I2C_HIGH_FREQ		400000
#define XLP9XX_I2C_FIFO_SIZE		0x80U
#define XLP9XX_I2C_TIMEOUT_MS		1000
#define XLP9XX_I2C_BUSY_TIMEOUT		50

#define XLP9XX_I2C_FIFO_WCNT_MASK	0xff
#define XLP9XX_I2C_STATUS_ERRMASK	(XLP9XX_I2C_INTEN_ARLOST | \
			XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_BUSERR)

struct xlp9xx_i2c_dev {
	struct device *dev;
	struct i2c_adapter adapter;
	struct completion msg_complete;
	int irq;
	bool msg_read;
	bool len_recv;
	bool client_pec;
	u32 __iomem *base;
	u32 msg_buf_remaining;
	u32 msg_len;
	u32 ip_clk_hz;
	u32 clk_hz;
	u32 msg_err;
	u8 *msg_buf;
};

static inline void xlp9xx_write_i2c_reg(struct xlp9xx_i2c_dev *priv,
					unsigned long reg, u32 val)
{
	writel(val, priv->base + reg);
}

static inline u32 xlp9xx_read_i2c_reg(struct xlp9xx_i2c_dev *priv,
				      unsigned long reg)
{
	return readl(priv->base + reg);
}

static void xlp9xx_i2c_mask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
{
	u32 inten;

	inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) & ~mask;
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
}

static void xlp9xx_i2c_unmask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
{
	u32 inten;

	inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) | mask;
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
}

static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev *priv)
{
	u32 thres;

	if (priv->len_recv)
		/* interrupt after the first read to examine
		 * the length byte before proceeding further
		 */
		thres = 1;
	else if (priv->msg_buf_remaining > XLP9XX_I2C_FIFO_SIZE)
		thres = XLP9XX_I2C_FIFO_SIZE;
	else
		thres = priv->msg_buf_remaining;

	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
			     thres << XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT);
}

static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv)
{
	u32 len, i;
	u8 *buf = priv->msg_buf;

	len = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE);
	for (i = 0; i < len; i++)
		xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MTXFIFO, buf[i]);
	priv->msg_buf_remaining -= len;
	priv->msg_buf += len;
}

static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
{
	u32 len, i, val;
	u8 rlen, *buf = priv->msg_buf;

	len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
				  XLP9XX_I2C_FIFO_WCNT_MASK;
	if (!len)
		return;
	if (priv->len_recv) {
		/* read length byte */
		rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
		*buf++ = rlen;
		len--;

		if (priv->client_pec)
			++rlen;
		/* update remaining bytes and message length */
		priv->msg_buf_remaining = rlen;
		priv->msg_len = rlen + 1;
		priv->len_recv = false;

		/* Update transfer length to read only actual data */
		val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
		val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
			((rlen + 1) << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
		xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
	} else {
		len = min(priv->msg_buf_remaining, len);
		for (i = 0; i < len; i++, buf++)
			*buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);

		priv->msg_buf_remaining -= len;
	}

	priv->msg_buf = buf;

	if (priv->msg_buf_remaining)
		xlp9xx_i2c_update_rx_fifo_thres(priv);
}

static irqreturn_t xlp9xx_i2c_isr(int irq, void *dev_id)
{
	struct xlp9xx_i2c_dev *priv = dev_id;
	u32 status;

	status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTST);
	if (status == 0)
		return IRQ_NONE;

	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTST, status);
	if (status & XLP9XX_I2C_STATUS_ERRMASK) {
		priv->msg_err = status;
		goto xfer_done;
	}

	/* SADDR ACK for SMBUS_QUICK */
	if ((status & XLP9XX_I2C_INTEN_SADDR) && (priv->msg_len == 0))
		goto xfer_done;

	if (!priv->msg_read) {
		if (status & XLP9XX_I2C_INTEN_MFIFOEMTY) {
			/* TX FIFO got empty, fill it up again */
			if (priv->msg_buf_remaining)
				xlp9xx_i2c_fill_tx_fifo(priv);
			else
				xlp9xx_i2c_mask_irq(priv,
						    XLP9XX_I2C_INTEN_MFIFOEMTY);
		}
	} else {
		if (status & (XLP9XX_I2C_INTEN_DATADONE |
			      XLP9XX_I2C_INTEN_MFIFOHI)) {
			/* data is in FIFO, read it */
			if (priv->msg_buf_remaining)
				xlp9xx_i2c_drain_rx_fifo(priv);
		}
	}

	/* Transfer complete */
	if (status & XLP9XX_I2C_INTEN_DATADONE)
		goto xfer_done;

	return IRQ_HANDLED;

xfer_done:
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
	complete(&priv->msg_complete);
	return IRQ_HANDLED;
}

static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev *priv)
{
	u32 status;
	u32 busy_timeout = XLP9XX_I2C_BUSY_TIMEOUT;

	while (busy_timeout) {
		status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_STATUS);
		if ((status & XLP9XX_I2C_STATUS_BUSY) == 0)
			break;

		busy_timeout--;
		usleep_range(1000, 1100);
	}

	if (!busy_timeout)
		return -EIO;

	return 0;
}

static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev *priv)
{
	u32 prescale;

	/*
	 * The controller uses 5 * SCL clock internally.
	 * So prescale value should be divided by 5.
	 */
	prescale = DIV_ROUND_UP(priv->ip_clk_hz, priv->clk_hz);
	prescale = ((prescale - 8) / 5) - 1;
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_RST);
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_EN |
			     XLP9XX_I2C_CTRL_MASTER);
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_DIV, prescale);
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);

	return 0;
}

static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg,
			       int last_msg)
{
	unsigned long timeleft;
	u32 intr_mask, cmd, val, len;

	priv->msg_buf = msg->buf;
	priv->msg_buf_remaining = priv->msg_len = msg->len;
	priv->msg_err = 0;
	priv->msg_read = (msg->flags & I2C_M_RD);
	reinit_completion(&priv->msg_complete);

	/* Reset FIFO */
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
			     XLP9XX_I2C_MFIFOCTRL_RST);

	/* set FIFO threshold if reading */
	if (priv->msg_read)
		xlp9xx_i2c_update_rx_fifo_thres(priv);

	/* set slave addr */
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_SLAVEADDR,
			     (msg->addr << XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT) |
			     (priv->msg_read ? XLP9XX_I2C_SLAVEADDR_RW : 0));

	/* Build control word for transfer */
	val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
	if (!priv->msg_read)
		val &= ~XLP9XX_I2C_CTRL_FIFORD;
	else
		val |= XLP9XX_I2C_CTRL_FIFORD;	/* read */

	if (msg->flags & I2C_M_TEN)
		val |= XLP9XX_I2C_CTRL_ADDMODE;	/* 10-bit address mode*/
	else
		val &= ~XLP9XX_I2C_CTRL_ADDMODE;

	priv->len_recv = msg->flags & I2C_M_RECV_LEN;
	len = priv->len_recv ? XLP9XX_I2C_FIFO_SIZE : msg->len;
	priv->client_pec = msg->flags & I2C_CLIENT_PEC;

	/* set data length to be transferred */
	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
	      (len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);

	/* fill fifo during tx */
	if (!priv->msg_read)
		xlp9xx_i2c_fill_tx_fifo(priv);

	/* set interrupt mask */
	intr_mask = (XLP9XX_I2C_INTEN_ARLOST | XLP9XX_I2C_INTEN_BUSERR |
		     XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_DATADONE);

	if (priv->msg_read) {
		intr_mask |= XLP9XX_I2C_INTEN_MFIFOHI;
		if (msg->len == 0)
			intr_mask |= XLP9XX_I2C_INTEN_SADDR;
	} else {
		if (msg->len == 0)
			intr_mask |= XLP9XX_I2C_INTEN_SADDR;
		else
			intr_mask |= XLP9XX_I2C_INTEN_MFIFOEMTY;
	}
	xlp9xx_i2c_unmask_irq(priv, intr_mask);

	/* set cmd reg */
	cmd = XLP9XX_I2C_CMD_START;
	cmd |= (priv->msg_read ? XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE);
	if (last_msg)
		cmd |= XLP9XX_I2C_CMD_STOP;

	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, cmd);

	timeleft = msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS);
	timeleft = wait_for_completion_timeout(&priv->msg_complete, timeleft);

	if (priv->msg_err) {
		dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err);
		if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR)
			xlp9xx_i2c_init(priv);
		return (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) ?
			-ENXIO : -EIO;
	}

	if (timeleft == 0) {
		dev_dbg(priv->dev, "i2c transfer timed out!\n");
		xlp9xx_i2c_init(priv);
		return -ETIMEDOUT;
	}

	/* update msg->len with actual received length */
	if (msg->flags & I2C_M_RECV_LEN)
		msg->len = priv->msg_len;
	return 0;
}

static int xlp9xx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
			   int num)
{
	int i, ret;
	struct xlp9xx_i2c_dev *priv = i2c_get_adapdata(adap);

	ret = xlp9xx_i2c_check_bus_status(priv);
	if (ret) {
		xlp9xx_i2c_init(priv);
		ret = xlp9xx_i2c_check_bus_status(priv);
		if (ret)
			return ret;
	}

	for (i = 0; i < num; i++) {
		ret = xlp9xx_i2c_xfer_msg(priv, &msgs[i], i == num - 1);
		if (ret != 0)
			return ret;
	}

	return num;
}

static u32 xlp9xx_i2c_functionality(struct i2c_adapter *adapter)
{
	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_READ_BLOCK_DATA |
			I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
}

static const struct i2c_algorithm xlp9xx_i2c_algo = {
	.master_xfer = xlp9xx_i2c_xfer,
	.functionality = xlp9xx_i2c_functionality,
};

static int xlp9xx_i2c_get_frequency(struct platform_device *pdev,
				    struct xlp9xx_i2c_dev *priv)
{
	struct clk *clk;
	u32 freq;
	int err;

	clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(clk)) {
		priv->ip_clk_hz = XLP9XX_I2C_IP_CLK_FREQ;
		dev_dbg(&pdev->dev, "using default input frequency %u\n",
			priv->ip_clk_hz);
	} else {
		priv->ip_clk_hz = clk_get_rate(clk);
	}

	err = device_property_read_u32(&pdev->dev, "clock-frequency", &freq);
	if (err) {
		freq = XLP9XX_I2C_DEFAULT_FREQ;
		dev_dbg(&pdev->dev, "using default frequency %u\n", freq);
	} else if (freq == 0 || freq > XLP9XX_I2C_HIGH_FREQ) {
		dev_warn(&pdev->dev, "invalid frequency %u, using default\n",
			 freq);
		freq = XLP9XX_I2C_DEFAULT_FREQ;
	}
	priv->clk_hz = freq;

	return 0;
}

static int xlp9xx_i2c_probe(struct platform_device *pdev)
{
	struct xlp9xx_i2c_dev *priv;
	struct resource *res;
	int err = 0;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(priv->base))
		return PTR_ERR(priv->base);

	priv->irq = platform_get_irq(pdev, 0);
	if (priv->irq <= 0) {
		dev_err(&pdev->dev, "invalid irq!\n");
		return priv->irq;
	}

	xlp9xx_i2c_get_frequency(pdev, priv);
	xlp9xx_i2c_init(priv);

	err = devm_request_irq(&pdev->dev, priv->irq, xlp9xx_i2c_isr, 0,
			       pdev->name, priv);
	if (err) {
		dev_err(&pdev->dev, "IRQ request failed!\n");
		return err;
	}

	init_completion(&priv->msg_complete);
	priv->adapter.dev.parent = &pdev->dev;
	priv->adapter.algo = &xlp9xx_i2c_algo;
	priv->adapter.class = I2C_CLASS_HWMON;
	ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
	priv->adapter.dev.of_node = pdev->dev.of_node;
	priv->dev = &pdev->dev;

	snprintf(priv->adapter.name, sizeof(priv->adapter.name), "xlp9xx-i2c");
	i2c_set_adapdata(&priv->adapter, priv);

	err = i2c_add_adapter(&priv->adapter);
	if (err)
		return err;

	platform_set_drvdata(pdev, priv);
	dev_dbg(&pdev->dev, "I2C bus:%d added\n", priv->adapter.nr);

	return 0;
}

static int xlp9xx_i2c_remove(struct platform_device *pdev)
{
	struct xlp9xx_i2c_dev *priv;

	priv = platform_get_drvdata(pdev);
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
	synchronize_irq(priv->irq);
	i2c_del_adapter(&priv->adapter);
	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, 0);

	return 0;
}

static const struct of_device_id xlp9xx_i2c_of_match[] = {
	{ .compatible = "netlogic,xlp980-i2c", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, xlp9xx_i2c_of_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id xlp9xx_i2c_acpi_ids[] = {
	{"BRCM9007", 0},
	{"CAV9007",  0},
	{}
};
MODULE_DEVICE_TABLE(acpi, xlp9xx_i2c_acpi_ids);
#endif

static struct platform_driver xlp9xx_i2c_driver = {
	.probe = xlp9xx_i2c_probe,
	.remove = xlp9xx_i2c_remove,
	.driver = {
		.name = "xlp9xx-i2c",
		.of_match_table = xlp9xx_i2c_of_match,
		.acpi_match_table = ACPI_PTR(xlp9xx_i2c_acpi_ids),
	},
};

module_platform_driver(xlp9xx_i2c_driver);

MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
2bbd681b SSB	1	/*
	2	* Copyright (c) 2003-2015 Broadcom Corporation
	3	*
	4	* This file is licensed under the terms of the GNU General Public
	5	* License version 2. This program is licensed "as is" without any
	6	* warranty of any kind, whether express or implied.
	7	*/
	8
748c0bbb	9	#include <linux/acpi.h>
c347b8fc	10	#include <linux/clk.h>
2bbd681b SSB	11	#include <linux/completion.h>
	12	#include <linux/i2c.h>
	13	#include <linux/init.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/io.h>
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/platform_device.h>
2fbdba2b	19	#include <linux/delay.h>
2bbd681b SSB	20
	21	#define XLP9XX_I2C_DIV 0x0
	22	#define XLP9XX_I2C_CTRL 0x1
	23	#define XLP9XX_I2C_CMD 0x2
	24	#define XLP9XX_I2C_STATUS 0x3
	25	#define XLP9XX_I2C_MTXFIFO 0x4
	26	#define XLP9XX_I2C_MRXFIFO 0x5
	27	#define XLP9XX_I2C_MFIFOCTRL 0x6
	28	#define XLP9XX_I2C_STXFIFO 0x7
	29	#define XLP9XX_I2C_SRXFIFO 0x8
	30	#define XLP9XX_I2C_SFIFOCTRL 0x9
	31	#define XLP9XX_I2C_SLAVEADDR 0xA
	32	#define XLP9XX_I2C_OWNADDR 0xB
	33	#define XLP9XX_I2C_FIFOWCNT 0xC
	34	#define XLP9XX_I2C_INTEN 0xD
	35	#define XLP9XX_I2C_INTST 0xE
	36	#define XLP9XX_I2C_WAITCNT 0xF
	37	#define XLP9XX_I2C_TIMEOUT 0X10
	38	#define XLP9XX_I2C_GENCALLADDR 0x11
	39
2fbdba2b GC	40	#define XLP9XX_I2C_STATUS_BUSY BIT(0)
2fbdba2b GC	41
2bbd681b SSB	42	#define XLP9XX_I2C_CMD_START BIT(7)
	43	#define XLP9XX_I2C_CMD_STOP BIT(6)
	44	#define XLP9XX_I2C_CMD_READ BIT(5)
	45	#define XLP9XX_I2C_CMD_WRITE BIT(4)
	46	#define XLP9XX_I2C_CMD_ACK BIT(3)
	47
	48	#define XLP9XX_I2C_CTRL_MCTLEN_SHIFT 16
	49	#define XLP9XX_I2C_CTRL_MCTLEN_MASK 0xffff0000
	50	#define XLP9XX_I2C_CTRL_RST BIT(8)
	51	#define XLP9XX_I2C_CTRL_EN BIT(6)
	52	#define XLP9XX_I2C_CTRL_MASTER BIT(4)
	53	#define XLP9XX_I2C_CTRL_FIFORD BIT(1)
	54	#define XLP9XX_I2C_CTRL_ADDMODE BIT(0)
	55
	56	#define XLP9XX_I2C_INTEN_NACKADDR BIT(25)
	57	#define XLP9XX_I2C_INTEN_SADDR BIT(13)
	58	#define XLP9XX_I2C_INTEN_DATADONE BIT(12)
	59	#define XLP9XX_I2C_INTEN_ARLOST BIT(11)
	60	#define XLP9XX_I2C_INTEN_MFIFOFULL BIT(4)
	61	#define XLP9XX_I2C_INTEN_MFIFOEMTY BIT(3)
	62	#define XLP9XX_I2C_INTEN_MFIFOHI BIT(2)
	63	#define XLP9XX_I2C_INTEN_BUSERR BIT(0)
	64
	65	#define XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT 8
	66	#define XLP9XX_I2C_MFIFOCTRL_LOTH_SHIFT 0
	67	#define XLP9XX_I2C_MFIFOCTRL_RST BIT(16)
	68
	69	#define XLP9XX_I2C_SLAVEADDR_RW BIT(0)
	70	#define XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT 1
	71
	72	#define XLP9XX_I2C_IP_CLK_FREQ 133000000UL
	73	#define XLP9XX_I2C_DEFAULT_FREQ 100000
	74	#define XLP9XX_I2C_HIGH_FREQ 400000
	75	#define XLP9XX_I2C_FIFO_SIZE 0x80U
	76	#define XLP9XX_I2C_TIMEOUT_MS 1000
2fbdba2b	77	#define XLP9XX_I2C_BUSY_TIMEOUT 50
2bbd681b SSB	78
	79	#define XLP9XX_I2C_FIFO_WCNT_MASK 0xff
	80	#define XLP9XX_I2C_STATUS_ERRMASK (XLP9XX_I2C_INTEN_ARLOST \| \
	81	XLP9XX_I2C_INTEN_NACKADDR \| XLP9XX_I2C_INTEN_BUSERR)
	82
	83	struct xlp9xx_i2c_dev {
	84	struct device *dev;
	85	struct i2c_adapter adapter;
	86	struct completion msg_complete;
	87	int irq;
	88	bool msg_read;
5515ae11 KP	89	bool len_recv;
5515ae11 KP	90	bool client_pec;
2bbd681b SSB	91	u32 __iomem *base;
	92	u32 msg_buf_remaining;
	93	u32 msg_len;
c347b8fc	94	u32 ip_clk_hz;
2bbd681b SSB	95	u32 clk_hz;
	96	u32 msg_err;
	97	u8 *msg_buf;
	98	};
	99
	100	static inline void xlp9xx_write_i2c_reg(struct xlp9xx_i2c_dev *priv,
	101	unsigned long reg, u32 val)
	102	{
	103	writel(val, priv->base + reg);
	104	}
	105
	106	static inline u32 xlp9xx_read_i2c_reg(struct xlp9xx_i2c_dev *priv,
	107	unsigned long reg)
	108	{
	109	return readl(priv->base + reg);
	110	}
	111
	112	static void xlp9xx_i2c_mask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
	113	{
	114	u32 inten;
	115
	116	inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) & ~mask;
	117	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
	118	}
	119
	120	static void xlp9xx_i2c_unmask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
	121	{
	122	u32 inten;
	123
	124	inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) \| mask;
	125	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
	126	}
	127
	128	static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev *priv)
	129	{
	130	u32 thres;
	131
323879c8 GC	132	if (priv->len_recv)
	133	/* interrupt after the first read to examine
	134	* the length byte before proceeding further
	135	*/
	136	thres = 1;
	137	else if (priv->msg_buf_remaining > XLP9XX_I2C_FIFO_SIZE)
	138	thres = XLP9XX_I2C_FIFO_SIZE;
	139	else
	140	thres = priv->msg_buf_remaining;
	141
2bbd681b SSB	142	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
	143	thres << XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT);
	144	}
	145
	146	static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv)
	147	{
	148	u32 len, i;
	149	u8 *buf = priv->msg_buf;
	150
	151	len = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE);
	152	for (i = 0; i < len; i++)
	153	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MTXFIFO, buf[i]);
	154	priv->msg_buf_remaining -= len;
	155	priv->msg_buf += len;
	156	}
	157
	158	static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
	159	{
323879c8	160	u32 len, i, val;
5515ae11	161	u8 rlen, *buf = priv->msg_buf;
2bbd681b SSB	162
	163	len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
	164	XLP9XX_I2C_FIFO_WCNT_MASK;
5515ae11 KP	165	if (!len)
	166	return;
	167	if (priv->len_recv) {
	168	/* read length byte */
	169	rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
	170	*buf++ = rlen;
	171	len--;
323879c8	172
5515ae11 KP	173	if (priv->client_pec)
	174	++rlen;
	175	/* update remaining bytes and message length */
	176	priv->msg_buf_remaining = rlen;
	177	priv->msg_len = rlen + 1;
	178	priv->len_recv = false;
5515ae11	179
323879c8 GC	180	/* Update transfer length to read only actual data */
	181	val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
	182	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) \|
	183	((rlen + 1) << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
	184	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
	185	} else {
	186	len = min(priv->msg_buf_remaining, len);
	187	for (i = 0; i < len; i++, buf++)
	188	*buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
	189
	190	priv->msg_buf_remaining -= len;
	191	}
2bbd681b	192
2bbd681b SSB	193	priv->msg_buf = buf;
	194
	195	if (priv->msg_buf_remaining)
	196	xlp9xx_i2c_update_rx_fifo_thres(priv);
	197	}
	198
	199	static irqreturn_t xlp9xx_i2c_isr(int irq, void *dev_id)
	200	{
	201	struct xlp9xx_i2c_dev *priv = dev_id;
	202	u32 status;
	203
	204	status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTST);
	205	if (status == 0)
	206	return IRQ_NONE;
	207
	208	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTST, status);
	209	if (status & XLP9XX_I2C_STATUS_ERRMASK) {
	210	priv->msg_err = status;
	211	goto xfer_done;
	212	}
	213
	214	/* SADDR ACK for SMBUS_QUICK */
	215	if ((status & XLP9XX_I2C_INTEN_SADDR) && (priv->msg_len == 0))
	216	goto xfer_done;
	217
	218	if (!priv->msg_read) {
	219	if (status & XLP9XX_I2C_INTEN_MFIFOEMTY) {
	220	/* TX FIFO got empty, fill it up again */
	221	if (priv->msg_buf_remaining)
	222	xlp9xx_i2c_fill_tx_fifo(priv);
	223	else
	224	xlp9xx_i2c_mask_irq(priv,
	225	XLP9XX_I2C_INTEN_MFIFOEMTY);
	226	}
	227	} else {
	228	if (status & (XLP9XX_I2C_INTEN_DATADONE \|
	229	XLP9XX_I2C_INTEN_MFIFOHI)) {
	230	/* data is in FIFO, read it */
	231	if (priv->msg_buf_remaining)
	232	xlp9xx_i2c_drain_rx_fifo(priv);
	233	}
	234	}
	235
	236	/* Transfer complete */
	237	if (status & XLP9XX_I2C_INTEN_DATADONE)
	238	goto xfer_done;
	239
	240	return IRQ_HANDLED;
	241
	242	xfer_done:
	243	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
	244	complete(&priv->msg_complete);
	245	return IRQ_HANDLED;
	246	}
	247
2fbdba2b GC	248	static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev *priv)
	249	{
	250	u32 status;
	251	u32 busy_timeout = XLP9XX_I2C_BUSY_TIMEOUT;
	252
	253	while (busy_timeout) {
	254	status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_STATUS);
	255	if ((status & XLP9XX_I2C_STATUS_BUSY) == 0)
	256	break;
	257
	258	busy_timeout--;
	259	usleep_range(1000, 1100);
	260	}
	261
	262	if (!busy_timeout)
	263	return -EIO;
	264
	265	return 0;
	266	}
	267
2bbd681b SSB	268	static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev *priv)
	269	{
	270	u32 prescale;
	271
	272	/*
	273	* The controller uses 5 * SCL clock internally.
	274	* So prescale value should be divided by 5.
	275	*/
c347b8fc	276	prescale = DIV_ROUND_UP(priv->ip_clk_hz, priv->clk_hz);
2bbd681b SSB	277	prescale = ((prescale - 8) / 5) - 1;
	278	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_RST);
	279	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_EN \|
	280	XLP9XX_I2C_CTRL_MASTER);
	281	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_DIV, prescale);
	282	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
	283
	284	return 0;
	285	}
	286
	287	static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev priv, struct i2c_msg msg,
	288	int last_msg)
	289	{
	290	unsigned long timeleft;
5515ae11	291	u32 intr_mask, cmd, val, len;
2bbd681b SSB	292
	293	priv->msg_buf = msg->buf;
	294	priv->msg_buf_remaining = priv->msg_len = msg->len;
	295	priv->msg_err = 0;
	296	priv->msg_read = (msg->flags & I2C_M_RD);
	297	reinit_completion(&priv->msg_complete);
	298
	299	/* Reset FIFO */
	300	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
	301	XLP9XX_I2C_MFIFOCTRL_RST);
	302
	303	/* set FIFO threshold if reading */
	304	if (priv->msg_read)
	305	xlp9xx_i2c_update_rx_fifo_thres(priv);
	306
	307	/* set slave addr */
	308	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_SLAVEADDR,
	309	(msg->addr << XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT) \|
	310	(priv->msg_read ? XLP9XX_I2C_SLAVEADDR_RW : 0));
	311
	312	/* Build control word for transfer */
	313	val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
	314	if (!priv->msg_read)
	315	val &= ~XLP9XX_I2C_CTRL_FIFORD;
	316	else
	317	val \|= XLP9XX_I2C_CTRL_FIFORD; /* read */
	318
	319	if (msg->flags & I2C_M_TEN)
	320	val \|= XLP9XX_I2C_CTRL_ADDMODE; /* 10-bit address mode*/
	321	else
	322	val &= ~XLP9XX_I2C_CTRL_ADDMODE;
	323
5515ae11 KP	324	priv->len_recv = msg->flags & I2C_M_RECV_LEN;
	325	len = priv->len_recv ? XLP9XX_I2C_FIFO_SIZE : msg->len;
	326	priv->client_pec = msg->flags & I2C_CLIENT_PEC;
	327
2bbd681b SSB	328	/* set data length to be transferred */
2bbd681b SSB	329	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) \|
5515ae11	330	(len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
2bbd681b SSB	331	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
	332
	333	/* fill fifo during tx */
	334	if (!priv->msg_read)
	335	xlp9xx_i2c_fill_tx_fifo(priv);
	336
	337	/* set interrupt mask */
	338	intr_mask = (XLP9XX_I2C_INTEN_ARLOST \| XLP9XX_I2C_INTEN_BUSERR \|
	339	XLP9XX_I2C_INTEN_NACKADDR \| XLP9XX_I2C_INTEN_DATADONE);
	340
	341	if (priv->msg_read) {
	342	intr_mask \|= XLP9XX_I2C_INTEN_MFIFOHI;
	343	if (msg->len == 0)
	344	intr_mask \|= XLP9XX_I2C_INTEN_SADDR;
	345	} else {
	346	if (msg->len == 0)
	347	intr_mask \|= XLP9XX_I2C_INTEN_SADDR;
	348	else
	349	intr_mask \|= XLP9XX_I2C_INTEN_MFIFOEMTY;
	350	}
	351	xlp9xx_i2c_unmask_irq(priv, intr_mask);
	352
	353	/* set cmd reg */
	354	cmd = XLP9XX_I2C_CMD_START;
	355	cmd \|= (priv->msg_read ? XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE);
	356	if (last_msg)
	357	cmd \|= XLP9XX_I2C_CMD_STOP;
	358
	359	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, cmd);
	360
	361	timeleft = msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS);
	362	timeleft = wait_for_completion_timeout(&priv->msg_complete, timeleft);
	363
	364	if (priv->msg_err) {
	365	dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err);
	366	if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR)
	367	xlp9xx_i2c_init(priv);
9fe4b5fe DB	368	return (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) ?
9fe4b5fe DB	369	-ENXIO : -EIO;
2bbd681b SSB	370	}
	371
	372	if (timeleft == 0) {
	373	dev_dbg(priv->dev, "i2c transfer timed out!\n");
	374	xlp9xx_i2c_init(priv);
	375	return -ETIMEDOUT;
	376	}
	377
5515ae11 KP	378	/* update msg->len with actual received length */
	379	if (msg->flags & I2C_M_RECV_LEN)
	380	msg->len = priv->msg_len;
2bbd681b SSB	381	return 0;
	382	}
	383
	384	static int xlp9xx_i2c_xfer(struct i2c_adapter adap, struct i2c_msg msgs,
	385	int num)
	386	{
	387	int i, ret;
	388	struct xlp9xx_i2c_dev *priv = i2c_get_adapdata(adap);
	389
2fbdba2b GC	390	ret = xlp9xx_i2c_check_bus_status(priv);
	391	if (ret) {
	392	xlp9xx_i2c_init(priv);
	393	ret = xlp9xx_i2c_check_bus_status(priv);
	394	if (ret)
	395	return ret;
	396	}
	397
2bbd681b SSB	398	for (i = 0; i < num; i++) {
	399	ret = xlp9xx_i2c_xfer_msg(priv, &msgs[i], i == num - 1);
	400	if (ret != 0)
	401	return ret;
	402	}
	403
	404	return num;
	405	}
	406
	407	static u32 xlp9xx_i2c_functionality(struct i2c_adapter *adapter)
	408	{
323879c8 GC	409	return I2C_FUNC_SMBUS_EMUL \| I2C_FUNC_SMBUS_READ_BLOCK_DATA \|
323879c8 GC	410	I2C_FUNC_I2C \| I2C_FUNC_10BIT_ADDR;
2bbd681b SSB	411	}
2bbd681b SSB	412
92d9d0df	413	static const struct i2c_algorithm xlp9xx_i2c_algo = {
2bbd681b SSB	414	.master_xfer = xlp9xx_i2c_xfer,
	415	.functionality = xlp9xx_i2c_functionality,
	416	};
	417
	418	static int xlp9xx_i2c_get_frequency(struct platform_device *pdev,
	419	struct xlp9xx_i2c_dev *priv)
	420	{
c347b8fc	421	struct clk *clk;
2bbd681b SSB	422	u32 freq;
	423	int err;
	424
c347b8fc J	425	clk = devm_clk_get(&pdev->dev, NULL);
	426	if (IS_ERR(clk)) {
	427	priv->ip_clk_hz = XLP9XX_I2C_IP_CLK_FREQ;
	428	dev_dbg(&pdev->dev, "using default input frequency %u\n",
	429	priv->ip_clk_hz);
	430	} else {
	431	priv->ip_clk_hz = clk_get_rate(clk);
	432	}
	433
748c0bbb	434	err = device_property_read_u32(&pdev->dev, "clock-frequency", &freq);
2bbd681b SSB	435	if (err) {
	436	freq = XLP9XX_I2C_DEFAULT_FREQ;
	437	dev_dbg(&pdev->dev, "using default frequency %u\n", freq);
	438	} else if (freq == 0 \|\| freq > XLP9XX_I2C_HIGH_FREQ) {
	439	dev_warn(&pdev->dev, "invalid frequency %u, using default\n",
	440	freq);
	441	freq = XLP9XX_I2C_DEFAULT_FREQ;
	442	}
	443	priv->clk_hz = freq;
	444
	445	return 0;
	446	}
	447
	448	static int xlp9xx_i2c_probe(struct platform_device *pdev)
	449	{
	450	struct xlp9xx_i2c_dev *priv;
	451	struct resource *res;
	452	int err = 0;
	453
	454	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	455	if (!priv)
	456	return -ENOMEM;
	457
	458	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	459	priv->base = devm_ioremap_resource(&pdev->dev, res);
	460	if (IS_ERR(priv->base))
	461	return PTR_ERR(priv->base);
	462
	463	priv->irq = platform_get_irq(pdev, 0);
	464	if (priv->irq <= 0) {
	465	dev_err(&pdev->dev, "invalid irq!\n");
	466	return priv->irq;
	467	}
	468
	469	xlp9xx_i2c_get_frequency(pdev, priv);
	470	xlp9xx_i2c_init(priv);
	471
	472	err = devm_request_irq(&pdev->dev, priv->irq, xlp9xx_i2c_isr, 0,
	473	pdev->name, priv);
	474	if (err) {
	475	dev_err(&pdev->dev, "IRQ request failed!\n");
	476	return err;
	477	}
	478
	479	init_completion(&priv->msg_complete);
	480	priv->adapter.dev.parent = &pdev->dev;
	481	priv->adapter.algo = &xlp9xx_i2c_algo;
227855b9	482	priv->adapter.class = I2C_CLASS_HWMON;
254df038	483	ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
2bbd681b SSB	484	priv->adapter.dev.of_node = pdev->dev.of_node;
	485	priv->dev = &pdev->dev;
	486
	487	snprintf(priv->adapter.name, sizeof(priv->adapter.name), "xlp9xx-i2c");
	488	i2c_set_adapdata(&priv->adapter, priv);
	489
	490	err = i2c_add_adapter(&priv->adapter);
ea734404	491	if (err)
2bbd681b	492	return err;
2bbd681b SSB	493
	494	platform_set_drvdata(pdev, priv);
	495	dev_dbg(&pdev->dev, "I2C bus:%d added\n", priv->adapter.nr);
	496
	497	return 0;
	498	}
	499
	500	static int xlp9xx_i2c_remove(struct platform_device *pdev)
	501	{
	502	struct xlp9xx_i2c_dev *priv;
	503
	504	priv = platform_get_drvdata(pdev);
	505	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
	506	synchronize_irq(priv->irq);
	507	i2c_del_adapter(&priv->adapter);
	508	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, 0);
	509
	510	return 0;
	511	}
	512
	513	static const struct of_device_id xlp9xx_i2c_of_match[] = {
	514	{ .compatible = "netlogic,xlp980-i2c", },
	515	{ /* sentinel */ },
	516	};
06e7b10a	517	MODULE_DEVICE_TABLE(of, xlp9xx_i2c_of_match);
2bbd681b	518
748c0bbb TJ	519	#ifdef CONFIG_ACPI
	520	static const struct acpi_device_id xlp9xx_i2c_acpi_ids[] = {
	521	{"BRCM9007", 0},
4165bd4b	522	{"CAV9007", 0},
748c0bbb TJ	523	{}
	524	};
	525	MODULE_DEVICE_TABLE(acpi, xlp9xx_i2c_acpi_ids);
	526	#endif
	527
2bbd681b SSB	528	static struct platform_driver xlp9xx_i2c_driver = {
	529	.probe = xlp9xx_i2c_probe,
	530	.remove = xlp9xx_i2c_remove,
	531	.driver = {
	532	.name = "xlp9xx-i2c",
	533	.of_match_table = xlp9xx_i2c_of_match,
748c0bbb	534	.acpi_match_table = ACPI_PTR(xlp9xx_i2c_acpi_ids),
2bbd681b SSB	535	},
	536	};
	537
	538	module_platform_driver(xlp9xx_i2c_driver);
	539
	540	MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
	541	MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
	542	MODULE_LICENSE("GPL v2");