Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 907 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
new file mode 100644
index 000000000..4914bfbee
--- /dev/null
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -0,0 +1,907 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+
+#define PCH_EVENT_SET	0	/* I2C Interrupt Event Set Status */
+#define PCH_EVENT_NONE	1	/* I2C Interrupt Event Clear Status */
+#define PCH_MAX_CLK		100000	/* Maximum Clock speed in MHz */
+#define PCH_BUFFER_MODE_ENABLE	0x0002	/* flag for Buffer mode enable */
+#define PCH_EEPROM_SW_RST_MODE_ENABLE	0x0008	/* EEPROM SW RST enable flag */
+
+#define PCH_I2CSADR	0x00	/* I2C slave address register */
+#define PCH_I2CCTL	0x04	/* I2C control register */
+#define PCH_I2CSR	0x08	/* I2C status register */
+#define PCH_I2CDR	0x0C	/* I2C data register */
+#define PCH_I2CMON	0x10	/* I2C bus monitor register */
+#define PCH_I2CBC	0x14	/* I2C bus transfer rate setup counter */
+#define PCH_I2CMOD	0x18	/* I2C mode register */
+#define PCH_I2CBUFSLV	0x1C	/* I2C buffer mode slave address register */
+#define PCH_I2CBUFSUB	0x20	/* I2C buffer mode subaddress register */
+#define PCH_I2CBUFFOR	0x24	/* I2C buffer mode format register */
+#define PCH_I2CBUFCTL	0x28	/* I2C buffer mode control register */
+#define PCH_I2CBUFMSK	0x2C	/* I2C buffer mode interrupt mask register */
+#define PCH_I2CBUFSTA	0x30	/* I2C buffer mode status register */
+#define PCH_I2CBUFLEV	0x34	/* I2C buffer mode level register */
+#define PCH_I2CESRFOR	0x38	/* EEPROM software reset mode format register */
+#define PCH_I2CESRCTL	0x3C	/* EEPROM software reset mode ctrl register */
+#define PCH_I2CESRMSK	0x40	/* EEPROM software reset mode */
+#define PCH_I2CESRSTA	0x44	/* EEPROM software reset mode status register */
+#define PCH_I2CTMR	0x48	/* I2C timer register */
+#define PCH_I2CSRST	0xFC	/* I2C reset register */
+#define PCH_I2CNF	0xF8	/* I2C noise filter register */
+
+#define BUS_IDLE_TIMEOUT	20
+#define PCH_I2CCTL_I2CMEN	0x0080
+#define TEN_BIT_ADDR_DEFAULT	0xF000
+#define TEN_BIT_ADDR_MASK	0xF0
+#define PCH_START		0x0020
+#define PCH_RESTART		0x0004
+#define PCH_ESR_START		0x0001
+#define PCH_BUFF_START		0x1
+#define PCH_REPSTART		0x0004
+#define PCH_ACK			0x0008
+#define PCH_GETACK		0x0001
+#define CLR_REG			0x0
+#define I2C_RD			0x1
+#define I2CMCF_BIT		0x0080
+#define I2CMIF_BIT		0x0002
+#define I2CMAL_BIT		0x0010
+#define I2CBMFI_BIT		0x0001
+#define I2CBMAL_BIT		0x0002
+#define I2CBMNA_BIT		0x0004
+#define I2CBMTO_BIT		0x0008
+#define I2CBMIS_BIT		0x0010
+#define I2CESRFI_BIT		0X0001
+#define I2CESRTO_BIT		0x0002
+#define I2CESRFIIE_BIT		0x1
+#define I2CESRTOIE_BIT		0x2
+#define I2CBMDZ_BIT		0x0040
+#define I2CBMAG_BIT		0x0020
+#define I2CMBB_BIT		0x0020
+#define BUFFER_MODE_MASK	(I2CBMFI_BIT | I2CBMAL_BIT | I2CBMNA_BIT | \
+				I2CBMTO_BIT | I2CBMIS_BIT)
+#define I2C_ADDR_MSK		0xFF
+#define I2C_MSB_2B_MSK		0x300
+#define FAST_MODE_CLK		400
+#define FAST_MODE_EN		0x0001
+#define SUB_ADDR_LEN_MAX	4
+#define BUF_LEN_MAX		32
+#define PCH_BUFFER_MODE		0x1
+#define EEPROM_SW_RST_MODE	0x0002
+#define NORMAL_INTR_ENBL	0x0300
+#define EEPROM_RST_INTR_ENBL	(I2CESRFIIE_BIT | I2CESRTOIE_BIT)
+#define EEPROM_RST_INTR_DISBL	0x0
+#define BUFFER_MODE_INTR_ENBL	0x001F
+#define BUFFER_MODE_INTR_DISBL	0x0
+#define NORMAL_MODE		0x0
+#define BUFFER_MODE		0x1
+#define EEPROM_SR_MODE		0x2
+#define I2C_TX_MODE		0x0010
+#define PCH_BUF_TX		0xFFF7
+#define PCH_BUF_RD		0x0008
+#define I2C_ERROR_MASK	(I2CESRTO_EVENT | I2CBMIS_EVENT | I2CBMTO_EVENT | \
+			I2CBMNA_EVENT | I2CBMAL_EVENT | I2CMAL_EVENT)
+#define I2CMAL_EVENT		0x0001
+#define I2CMCF_EVENT		0x0002
+#define I2CBMFI_EVENT		0x0004
+#define I2CBMAL_EVENT		0x0008
+#define I2CBMNA_EVENT		0x0010
+#define I2CBMTO_EVENT		0x0020
+#define I2CBMIS_EVENT		0x0040
+#define I2CESRFI_EVENT		0x0080
+#define I2CESRTO_EVENT		0x0100
+#define PCI_DEVICE_ID_PCH_I2C	0x8817
+
+#define pch_dbg(adap, fmt, arg...)  \
+	dev_dbg(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
+
+#define pch_err(adap, fmt, arg...)  \
+	dev_err(adap->pch_adapter.dev.parent, "%s :" fmt, __func__, ##arg)
+
+#define pch_pci_err(pdev, fmt, arg...)  \
+	dev_err(&pdev->dev, "%s :" fmt, __func__, ##arg)
+
+#define pch_pci_dbg(pdev, fmt, arg...)  \
+	dev_dbg(&pdev->dev, "%s :" fmt, __func__, ##arg)
+
+/*
+Set the number of I2C instance max
+Intel EG20T PCH :		1ch
+LAPIS Semiconductor ML7213 IOH :	2ch
+LAPIS Semiconductor ML7831 IOH :	1ch
+*/
+#define PCH_I2C_MAX_DEV			2
+
+/**
+ * struct i2c_algo_pch_data - for I2C driver functionalities
+ * @pch_adapter:		stores the reference to i2c_adapter structure
+ * @p_adapter_info:		stores the reference to adapter_info structure
+ * @pch_base_address:		specifies the remapped base address
+ * @pch_buff_mode_en:		specifies if buffer mode is enabled
+ * @pch_event_flag:		specifies occurrence of interrupt events
+ * @pch_i2c_xfer_in_progress:	specifies whether the transfer is completed
+ */
+struct i2c_algo_pch_data {
+	struct i2c_adapter pch_adapter;
+	struct adapter_info *p_adapter_info;
+	void __iomem *pch_base_address;
+	int pch_buff_mode_en;
+	u32 pch_event_flag;
+	bool pch_i2c_xfer_in_progress;
+};
+
+/**
+ * struct adapter_info - This structure holds the adapter information for the
+ *			 PCH i2c controller
+ * @pch_data:		stores a list of i2c_algo_pch_data
+ * @pch_i2c_suspended:	specifies whether the system is suspended or not
+ *			perhaps with more lines and words.
+ * @ch_num:		specifies the number of i2c instance
+ *
+ * pch_data has as many elements as maximum I2C channels
+ */
+struct adapter_info {
+	struct i2c_algo_pch_data pch_data[PCH_I2C_MAX_DEV];
+	bool pch_i2c_suspended;
+	int ch_num;
+};
+
+
+static int pch_i2c_speed = 100; /* I2C bus speed in Kbps */
+static int pch_clk = 50000;	/* specifies I2C clock speed in KHz */
+static wait_queue_head_t pch_event;
+static DEFINE_MUTEX(pch_mutex);
+
+/* Definition for ML7213 by LAPIS Semiconductor */
+#define PCI_DEVICE_ID_ML7213_I2C	0x802D
+#define PCI_DEVICE_ID_ML7223_I2C	0x8010
+#define PCI_DEVICE_ID_ML7831_I2C	0x8817
+
+static const struct pci_device_id pch_pcidev_id[] = {
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PCH_I2C),   1, },
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_I2C), 2, },
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_I2C), 1, },
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_I2C), 1, },
+	{0,}
+};
+MODULE_DEVICE_TABLE(pci, pch_pcidev_id);
+
+static irqreturn_t pch_i2c_handler(int irq, void *pData);
+
+static inline void pch_setbit(void __iomem *addr, u32 offset, u32 bitmask)
+{
+	u32 val;
+	val = ioread32(addr + offset);
+	val |= bitmask;
+	iowrite32(val, addr + offset);
+}
+
+static inline void pch_clrbit(void __iomem *addr, u32 offset, u32 bitmask)
+{
+	u32 val;
+	val = ioread32(addr + offset);
+	val &= (~bitmask);
+	iowrite32(val, addr + offset);
+}
+
+/**
+ * pch_i2c_init() - hardware initialization of I2C module
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_init(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	u32 pch_i2cbc;
+	u32 pch_i2ctmr;
+	u32 reg_value;
+
+	/* reset I2C controller */
+	iowrite32(0x01, p + PCH_I2CSRST);
+	msleep(20);
+	iowrite32(0x0, p + PCH_I2CSRST);
+
+	/* Initialize I2C registers */
+	iowrite32(0x21, p + PCH_I2CNF);
+
+	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_I2CCTL_I2CMEN);
+
+	if (pch_i2c_speed != 400)
+		pch_i2c_speed = 100;
+
+	reg_value = PCH_I2CCTL_I2CMEN;
+	if (pch_i2c_speed == FAST_MODE_CLK) {
+		reg_value |= FAST_MODE_EN;
+		pch_dbg(adap, "Fast mode enabled\n");
+	}
+
+	if (pch_clk > PCH_MAX_CLK)
+		pch_clk = 62500;
+
+	pch_i2cbc = (pch_clk + (pch_i2c_speed * 4)) / (pch_i2c_speed * 8);
+	/* Set transfer speed in I2CBC */
+	iowrite32(pch_i2cbc, p + PCH_I2CBC);
+
+	pch_i2ctmr = (pch_clk) / 8;
+	iowrite32(pch_i2ctmr, p + PCH_I2CTMR);
+
+	reg_value |= NORMAL_INTR_ENBL;	/* Enable interrupts in normal mode */
+	iowrite32(reg_value, p + PCH_I2CCTL);
+
+	pch_dbg(adap,
+		"I2CCTL=%x pch_i2cbc=%x pch_i2ctmr=%x Enable interrupts\n",
+		ioread32(p + PCH_I2CCTL), pch_i2cbc, pch_i2ctmr);
+
+	init_waitqueue_head(&pch_event);
+}
+
+/**
+ * pch_i2c_wait_for_bus_idle() - check the status of bus.
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ * @timeout:	waiting time counter (ms).
+ */
+static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
+				     s32 timeout)
+{
+	void __iomem *p = adap->pch_base_address;
+	int schedule = 0;
+	unsigned long end = jiffies + msecs_to_jiffies(timeout);
+
+	while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
+		if (time_after(jiffies, end)) {
+			pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
+			pch_err(adap, "%s: Timeout Error.return%d\n",
+					__func__, -ETIME);
+			pch_i2c_init(adap);
+
+			return -ETIME;
+		}
+
+		if (!schedule)
+			/* Retry after some usecs */
+			udelay(5);
+		else
+			/* Wait a bit more without consuming CPU */
+			usleep_range(20, 1000);
+
+		schedule = 1;
+	}
+
+	return 0;
+}
+
+/**
+ * pch_i2c_start() - Generate I2C start condition in normal mode.
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ *
+ * Generate I2C start condition in normal mode by setting I2CCTL.I2CMSTA to 1.
+ */
+static void pch_i2c_start(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
+	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
+}
+
+/**
+ * pch_i2c_stop() - generate stop condition in normal mode.
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_stop(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
+	/* clear the start bit */
+	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_START);
+}
+
+static int pch_i2c_wait_for_check_xfer(struct i2c_algo_pch_data *adap)
+{
+	long ret;
+	void __iomem *p = adap->pch_base_address;
+
+	ret = wait_event_timeout(pch_event,
+			(adap->pch_event_flag != 0), msecs_to_jiffies(1000));
+	if (!ret) {
+		pch_err(adap, "%s:wait-event timeout\n", __func__);
+		adap->pch_event_flag = 0;
+		pch_i2c_stop(adap);
+		pch_i2c_init(adap);
+		return -ETIMEDOUT;
+	}
+
+	if (adap->pch_event_flag & I2C_ERROR_MASK) {
+		pch_err(adap, "Lost Arbitration\n");
+		adap->pch_event_flag = 0;
+		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
+		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
+		pch_i2c_init(adap);
+		return -EAGAIN;
+	}
+
+	adap->pch_event_flag = 0;
+
+	if (ioread32(p + PCH_I2CSR) & PCH_GETACK) {
+		pch_dbg(adap, "Receive NACK for slave address setting\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+/**
+ * pch_i2c_repstart() - generate repeated start condition in normal mode
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_repstart(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
+	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_REPSTART);
+}
+
+/**
+ * pch_i2c_writebytes() - write data to I2C bus in normal mode
+ * @i2c_adap:	Pointer to the struct i2c_adapter.
+ * @msgs:	Pointer to the i2c message structure.
+ * @last:	specifies whether last message or not.
+ *		In the case of compound mode it will be 1 for last message,
+ *		otherwise 0.
+ * @first:	specifies whether first message or not.
+ *		1 for first message otherwise 0.
+ */
+static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
+			      struct i2c_msg *msgs, u32 last, u32 first)
+{
+	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
+	u8 *buf;
+	u32 length;
+	u32 addr;
+	u32 addr_2_msb;
+	u32 addr_8_lsb;
+	s32 wrcount;
+	s32 rtn;
+	void __iomem *p = adap->pch_base_address;
+
+	length = msgs->len;
+	buf = msgs->buf;
+	addr = msgs->addr;
+
+	/* enable master tx */
+	pch_setbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
+
+	pch_dbg(adap, "I2CCTL = %x msgs->len = %d\n", ioread32(p + PCH_I2CCTL),
+		length);
+
+	if (first) {
+		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
+			return -ETIME;
+	}
+
+	if (msgs->flags & I2C_M_TEN) {
+		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7) & 0x06;
+		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
+		if (first)
+			pch_i2c_start(adap);
+
+		rtn = pch_i2c_wait_for_check_xfer(adap);
+		if (rtn)
+			return rtn;
+
+		addr_8_lsb = (addr & I2C_ADDR_MSK);
+		iowrite32(addr_8_lsb, p + PCH_I2CDR);
+	} else {
+		/* set 7 bit slave address and R/W bit as 0 */
+		iowrite32(i2c_8bit_addr_from_msg(msgs), p + PCH_I2CDR);
+		if (first)
+			pch_i2c_start(adap);
+	}
+
+	rtn = pch_i2c_wait_for_check_xfer(adap);
+	if (rtn)
+		return rtn;
+
+	for (wrcount = 0; wrcount < length; ++wrcount) {
+		/* write buffer value to I2C data register */
+		iowrite32(buf[wrcount], p + PCH_I2CDR);
+		pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);
+
+		rtn = pch_i2c_wait_for_check_xfer(adap);
+		if (rtn)
+			return rtn;
+
+		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMCF_BIT);
+		pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
+	}
+
+	/* check if this is the last message */
+	if (last)
+		pch_i2c_stop(adap);
+	else
+		pch_i2c_repstart(adap);
+
+	pch_dbg(adap, "return=%d\n", wrcount);
+
+	return wrcount;
+}
+
+/**
+ * pch_i2c_sendack() - send ACK
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_sendack(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
+	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
+}
+
+/**
+ * pch_i2c_sendnack() - send NACK
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_sendnack(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
+	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_ACK);
+}
+
+/**
+ * pch_i2c_restart() - Generate I2C restart condition in normal mode.
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ *
+ * Generate I2C restart condition in normal mode by setting I2CCTL.I2CRSTA.
+ */
+static void pch_i2c_restart(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+	pch_dbg(adap, "I2CCTL = %x\n", ioread32(p + PCH_I2CCTL));
+	pch_setbit(adap->pch_base_address, PCH_I2CCTL, PCH_RESTART);
+}
+
+/**
+ * pch_i2c_readbytes() - read data  from I2C bus in normal mode.
+ * @i2c_adap:	Pointer to the struct i2c_adapter.
+ * @msgs:	Pointer to i2c_msg structure.
+ * @last:	specifies whether last message or not.
+ * @first:	specifies whether first message or not.
+ */
+static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
+			     u32 last, u32 first)
+{
+	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
+
+	u8 *buf;
+	u32 count;
+	u32 length;
+	u32 addr;
+	u32 addr_2_msb;
+	u32 addr_8_lsb;
+	void __iomem *p = adap->pch_base_address;
+	s32 rtn;
+
+	length = msgs->len;
+	buf = msgs->buf;
+	addr = msgs->addr;
+
+	/* enable master reception */
+	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, I2C_TX_MODE);
+
+	if (first) {
+		if (pch_i2c_wait_for_bus_idle(adap, BUS_IDLE_TIMEOUT) == -ETIME)
+			return -ETIME;
+	}
+
+	if (msgs->flags & I2C_M_TEN) {
+		addr_2_msb = ((addr & I2C_MSB_2B_MSK) >> 7);
+		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
+		if (first)
+			pch_i2c_start(adap);
+
+		rtn = pch_i2c_wait_for_check_xfer(adap);
+		if (rtn)
+			return rtn;
+
+		addr_8_lsb = (addr & I2C_ADDR_MSK);
+		iowrite32(addr_8_lsb, p + PCH_I2CDR);
+
+		pch_i2c_restart(adap);
+
+		rtn = pch_i2c_wait_for_check_xfer(adap);
+		if (rtn)
+			return rtn;
+
+		addr_2_msb |= I2C_RD;
+		iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
+	} else {
+		/* 7 address bits + R/W bit */
+		iowrite32(i2c_8bit_addr_from_msg(msgs), p + PCH_I2CDR);
+	}
+
+	/* check if it is the first message */
+	if (first)
+		pch_i2c_start(adap);
+
+	rtn = pch_i2c_wait_for_check_xfer(adap);
+	if (rtn)
+		return rtn;
+
+	if (length == 0) {
+		pch_i2c_stop(adap);
+		ioread32(p + PCH_I2CDR); /* Dummy read needs */
+
+		count = length;
+	} else {
+		int read_index;
+		int loop;
+		pch_i2c_sendack(adap);
+
+		/* Dummy read */
+		for (loop = 1, read_index = 0; loop < length; loop++) {
+			buf[read_index] = ioread32(p + PCH_I2CDR);
+
+			if (loop != 1)
+				read_index++;
+
+			rtn = pch_i2c_wait_for_check_xfer(adap);
+			if (rtn)
+				return rtn;
+		}	/* end for */
+
+		pch_i2c_sendnack(adap);
+
+		buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */
+
+		if (length != 1)
+			read_index++;
+
+		rtn = pch_i2c_wait_for_check_xfer(adap);
+		if (rtn)
+			return rtn;
+
+		if (last)
+			pch_i2c_stop(adap);
+		else
+			pch_i2c_repstart(adap);
+
+		buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
+		count = read_index;
+	}
+
+	return count;
+}
+
+/**
+ * pch_i2c_cb() - Interrupt handler Call back function
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_cb(struct i2c_algo_pch_data *adap)
+{
+	u32 sts;
+	void __iomem *p = adap->pch_base_address;
+
+	sts = ioread32(p + PCH_I2CSR);
+	sts &= (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT);
+	if (sts & I2CMAL_BIT)
+		adap->pch_event_flag |= I2CMAL_EVENT;
+
+	if (sts & I2CMCF_BIT)
+		adap->pch_event_flag |= I2CMCF_EVENT;
+
+	/* clear the applicable bits */
+	pch_clrbit(adap->pch_base_address, PCH_I2CSR, sts);
+
+	pch_dbg(adap, "PCH_I2CSR = %x\n", ioread32(p + PCH_I2CSR));
+
+	wake_up(&pch_event);
+}
+
+/**
+ * pch_i2c_handler() - interrupt handler for the PCH I2C controller
+ * @irq:	irq number.
+ * @pData:	cookie passed back to the handler function.
+ */
+static irqreturn_t pch_i2c_handler(int irq, void *pData)
+{
+	u32 reg_val;
+	int flag;
+	int i;
+	struct adapter_info *adap_info = pData;
+	void __iomem *p;
+	u32 mode;
+
+	for (i = 0, flag = 0; i < adap_info->ch_num; i++) {
+		p = adap_info->pch_data[i].pch_base_address;
+		mode = ioread32(p + PCH_I2CMOD);
+		mode &= BUFFER_MODE | EEPROM_SR_MODE;
+		if (mode != NORMAL_MODE) {
+			pch_err(adap_info->pch_data,
+				"I2C-%d mode(%d) is not supported\n", mode, i);
+			continue;
+		}
+		reg_val = ioread32(p + PCH_I2CSR);
+		if (reg_val & (I2CMAL_BIT | I2CMCF_BIT | I2CMIF_BIT)) {
+			pch_i2c_cb(&adap_info->pch_data[i]);
+			flag = 1;
+		}
+	}
+
+	return flag ? IRQ_HANDLED : IRQ_NONE;
+}
+
+/**
+ * pch_i2c_xfer() - Reading adnd writing data through I2C bus
+ * @i2c_adap:	Pointer to the struct i2c_adapter.
+ * @msgs:	Pointer to i2c_msg structure.
+ * @num:	number of messages.
+ */
+static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
+			struct i2c_msg *msgs, s32 num)
+{
+	struct i2c_msg *pmsg;
+	u32 i = 0;
+	u32 status;
+	s32 ret;
+
+	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
+
+	ret = mutex_lock_interruptible(&pch_mutex);
+	if (ret)
+		return ret;
+
+	if (adap->p_adapter_info->pch_i2c_suspended) {
+		mutex_unlock(&pch_mutex);
+		return -EBUSY;
+	}
+
+	pch_dbg(adap, "adap->p_adapter_info->pch_i2c_suspended is %d\n",
+		adap->p_adapter_info->pch_i2c_suspended);
+	/* transfer not completed */
+	adap->pch_i2c_xfer_in_progress = true;
+
+	for (i = 0; i < num && ret >= 0; i++) {
+		pmsg = &msgs[i];
+		pmsg->flags |= adap->pch_buff_mode_en;
+		status = pmsg->flags;
+		pch_dbg(adap,
+			"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
+
+		if ((status & (I2C_M_RD)) != false) {
+			ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
+						(i == 0));
+		} else {
+			ret = pch_i2c_writebytes(i2c_adap, pmsg, (i + 1 == num),
+						 (i == 0));
+		}
+	}
+
+	adap->pch_i2c_xfer_in_progress = false;	/* transfer completed */
+
+	mutex_unlock(&pch_mutex);
+
+	return (ret < 0) ? ret : num;
+}
+
+/**
+ * pch_i2c_func() - return the functionality of the I2C driver
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static u32 pch_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
+}
+
+static const struct i2c_algorithm pch_algorithm = {
+	.master_xfer = pch_i2c_xfer,
+	.functionality = pch_i2c_func
+};
+
+/**
+ * pch_i2c_disbl_int() - Disable PCH I2C interrupts
+ * @adap:	Pointer to struct i2c_algo_pch_data.
+ */
+static void pch_i2c_disbl_int(struct i2c_algo_pch_data *adap)
+{
+	void __iomem *p = adap->pch_base_address;
+
+	pch_clrbit(adap->pch_base_address, PCH_I2CCTL, NORMAL_INTR_ENBL);
+
+	iowrite32(EEPROM_RST_INTR_DISBL, p + PCH_I2CESRMSK);
+
+	iowrite32(BUFFER_MODE_INTR_DISBL, p + PCH_I2CBUFMSK);
+}
+
+static int pch_i2c_probe(struct pci_dev *pdev,
+				   const struct pci_device_id *id)
+{
+	void __iomem *base_addr;
+	int ret;
+	int i, j;
+	struct adapter_info *adap_info;
+	struct i2c_adapter *pch_adap;
+
+	pch_pci_dbg(pdev, "Entered.\n");
+
+	adap_info = kzalloc((sizeof(struct adapter_info)), GFP_KERNEL);
+	if (adap_info == NULL)
+		return -ENOMEM;
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		pch_pci_err(pdev, "pci_enable_device FAILED\n");
+		goto err_pci_enable;
+	}
+
+	ret = pci_request_regions(pdev, KBUILD_MODNAME);
+	if (ret) {
+		pch_pci_err(pdev, "pci_request_regions FAILED\n");
+		goto err_pci_req;
+	}
+
+	base_addr = pci_iomap(pdev, 1, 0);
+
+	if (base_addr == NULL) {
+		pch_pci_err(pdev, "pci_iomap FAILED\n");
+		ret = -ENOMEM;
+		goto err_pci_iomap;
+	}
+
+	/* Set the number of I2C channel instance */
+	adap_info->ch_num = id->driver_data;
+
+	for (i = 0; i < adap_info->ch_num; i++) {
+		pch_adap = &adap_info->pch_data[i].pch_adapter;
+		adap_info->pch_i2c_suspended = false;
+
+		adap_info->pch_data[i].p_adapter_info = adap_info;
+
+		pch_adap->owner = THIS_MODULE;
+		pch_adap->class = I2C_CLASS_HWMON;
+		strscpy(pch_adap->name, KBUILD_MODNAME, sizeof(pch_adap->name));
+		pch_adap->algo = &pch_algorithm;
+		pch_adap->algo_data = &adap_info->pch_data[i];
+
+		/* base_addr + offset; */
+		adap_info->pch_data[i].pch_base_address = base_addr + 0x100 * i;
+
+		pch_adap->dev.of_node = pdev->dev.of_node;
+		pch_adap->dev.parent = &pdev->dev;
+	}
+
+	ret = request_irq(pdev->irq, pch_i2c_handler, IRQF_SHARED,
+		  KBUILD_MODNAME, adap_info);
+	if (ret) {
+		pch_pci_err(pdev, "request_irq FAILED\n");
+		goto err_request_irq;
+	}
+
+	for (i = 0; i < adap_info->ch_num; i++) {
+		pch_adap = &adap_info->pch_data[i].pch_adapter;
+
+		pch_i2c_init(&adap_info->pch_data[i]);
+
+		pch_adap->nr = i;
+		ret = i2c_add_numbered_adapter(pch_adap);
+		if (ret) {
+			pch_pci_err(pdev, "i2c_add_adapter[ch:%d] FAILED\n", i);
+			goto err_add_adapter;
+		}
+	}
+
+	pci_set_drvdata(pdev, adap_info);
+	pch_pci_dbg(pdev, "returns %d.\n", ret);
+	return 0;
+
+err_add_adapter:
+	for (j = 0; j < i; j++)
+		i2c_del_adapter(&adap_info->pch_data[j].pch_adapter);
+	free_irq(pdev->irq, adap_info);
+err_request_irq:
+	pci_iounmap(pdev, base_addr);
+err_pci_iomap:
+	pci_release_regions(pdev);
+err_pci_req:
+	pci_disable_device(pdev);
+err_pci_enable:
+	kfree(adap_info);
+	return ret;
+}
+
+static void pch_i2c_remove(struct pci_dev *pdev)
+{
+	int i;
+	struct adapter_info *adap_info = pci_get_drvdata(pdev);
+
+	free_irq(pdev->irq, adap_info);
+
+	for (i = 0; i < adap_info->ch_num; i++) {
+		pch_i2c_disbl_int(&adap_info->pch_data[i]);
+		i2c_del_adapter(&adap_info->pch_data[i].pch_adapter);
+	}
+
+	if (adap_info->pch_data[0].pch_base_address)
+		pci_iounmap(pdev, adap_info->pch_data[0].pch_base_address);
+
+	for (i = 0; i < adap_info->ch_num; i++)
+		adap_info->pch_data[i].pch_base_address = NULL;
+
+	pci_release_regions(pdev);
+
+	pci_disable_device(pdev);
+	kfree(adap_info);
+}
+
+static int __maybe_unused pch_i2c_suspend(struct device *dev)
+{
+	int i;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct adapter_info *adap_info = pci_get_drvdata(pdev);
+	void __iomem *p = adap_info->pch_data[0].pch_base_address;
+
+	adap_info->pch_i2c_suspended = true;
+
+	for (i = 0; i < adap_info->ch_num; i++) {
+		while ((adap_info->pch_data[i].pch_i2c_xfer_in_progress)) {
+			/* Wait until all channel transfers are completed */
+			msleep(20);
+		}
+	}
+
+	/* Disable the i2c interrupts */
+	for (i = 0; i < adap_info->ch_num; i++)
+		pch_i2c_disbl_int(&adap_info->pch_data[i]);
+
+	pch_pci_dbg(pdev, "I2CSR = %x I2CBUFSTA = %x I2CESRSTA = %x "
+		"invoked function pch_i2c_disbl_int successfully\n",
+		ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
+		ioread32(p + PCH_I2CESRSTA));
+
+	return 0;
+}
+
+static int __maybe_unused pch_i2c_resume(struct device *dev)
+{
+	int i;
+	struct adapter_info *adap_info = dev_get_drvdata(dev);
+
+	for (i = 0; i < adap_info->ch_num; i++)
+		pch_i2c_init(&adap_info->pch_data[i]);
+
+	adap_info->pch_i2c_suspended = false;
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(pch_i2c_pm_ops, pch_i2c_suspend, pch_i2c_resume);
+
+static struct pci_driver pch_pcidriver = {
+	.name = KBUILD_MODNAME,
+	.id_table = pch_pcidev_id,
+	.probe = pch_i2c_probe,
+	.remove = pch_i2c_remove,
+	.driver.pm = &pch_i2c_pm_ops,
+};
+
+module_pci_driver(pch_pcidriver);
+
+MODULE_DESCRIPTION("Intel EG20T PCH/LAPIS Semico ML7213/ML7223/ML7831 IOH I2C");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tomoya MORINAGA. <tomoya.rohm@gmail.com>");
+module_param(pch_i2c_speed, int, (S_IRUSR | S_IWUSR));
+module_param(pch_clk, int, (S_IRUSR | S_IWUSR));