Release 4.7 drivers/i2c/busses/i2c-nomadik.c

/*
 * Copyright (C) 2009 ST-Ericsson SA
 * Copyright (C) 2009 STMicroelectronics
 *
 * I2C master mode controller driver, used in Nomadik 8815
 * and Ux500 platforms.
 *
 * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
 * Author: Sachin Verma <sachin.verma@st.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2, as
 * published by the Free Software Foundation.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>


#define DRIVER_NAME "nmk-i2c"

/* I2C Controller register offsets */

#define I2C_CR		(0x000)

#define I2C_SCR		(0x004)

#define I2C_HSMCR	(0x008)

#define I2C_MCR		(0x00C)

#define I2C_TFR		(0x010)

#define I2C_SR		(0x014)

#define I2C_RFR		(0x018)

#define I2C_TFTR	(0x01C)

#define I2C_RFTR	(0x020)

#define I2C_DMAR	(0x024)

#define I2C_BRCR	(0x028)

#define I2C_IMSCR	(0x02C)

#define I2C_RISR	(0x030)

#define I2C_MISR	(0x034)

#define I2C_ICR		(0x038)

/* Control registers */

#define I2C_CR_PE		(0x1 << 0)	
/* Peripheral Enable */

#define I2C_CR_OM		(0x3 << 1)	
/* Operating mode */

#define I2C_CR_SAM		(0x1 << 3)	
/* Slave addressing mode */

#define I2C_CR_SM		(0x3 << 4)	
/* Speed mode */

#define I2C_CR_SGCM		(0x1 << 6)	
/* Slave general call mode */

#define I2C_CR_FTX		(0x1 << 7)	
/* Flush Transmit */

#define I2C_CR_FRX		(0x1 << 8)	
/* Flush Receive */

#define I2C_CR_DMA_TX_EN	(0x1 << 9)	
/* DMA Tx enable */

#define I2C_CR_DMA_RX_EN	(0x1 << 10)	
/* DMA Rx Enable */

#define I2C_CR_DMA_SLE		(0x1 << 11)	
/* DMA sync. logic enable */

#define I2C_CR_LM		(0x1 << 12)	
/* Loopback mode */

#define I2C_CR_FON		(0x3 << 13)	
/* Filtering on */

#define I2C_CR_FS		(0x3 << 15)	
/* Force stop enable */

/* Master controller (MCR) register */

#define I2C_MCR_OP		(0x1 << 0)	
/* Operation */

#define I2C_MCR_A7		(0x7f << 1)	
/* 7-bit address */

#define I2C_MCR_EA10		(0x7 << 8)	
/* 10-bit Extended address */

#define I2C_MCR_SB		(0x1 << 11)	
/* Extended address */

#define I2C_MCR_AM		(0x3 << 12)	
/* Address type */

#define I2C_MCR_STOP		(0x1 << 14)	
/* Stop condition */

#define I2C_MCR_LENGTH		(0x7ff << 15)	
/* Transaction length */

/* Status register (SR) */

#define I2C_SR_OP		(0x3 << 0)	
/* Operation */

#define I2C_SR_STATUS		(0x3 << 2)	
/* controller status */

#define I2C_SR_CAUSE		(0x7 << 4)	
/* Abort cause */

#define I2C_SR_TYPE		(0x3 << 7)	
/* Receive type */

#define I2C_SR_LENGTH		(0x7ff << 9)	
/* Transfer length */

/* Interrupt mask set/clear (IMSCR) bits */

#define I2C_IT_TXFE		(0x1 << 0)

#define I2C_IT_TXFNE		(0x1 << 1)

#define I2C_IT_TXFF		(0x1 << 2)

#define I2C_IT_TXFOVR		(0x1 << 3)

#define I2C_IT_RXFE		(0x1 << 4)

#define I2C_IT_RXFNF		(0x1 << 5)

#define I2C_IT_RXFF		(0x1 << 6)

#define I2C_IT_RFSR		(0x1 << 16)

#define I2C_IT_RFSE		(0x1 << 17)

#define I2C_IT_WTSR		(0x1 << 18)

#define I2C_IT_MTD		(0x1 << 19)

#define I2C_IT_STD		(0x1 << 20)

#define I2C_IT_MAL		(0x1 << 24)

#define I2C_IT_BERR		(0x1 << 25)

#define I2C_IT_MTDWS		(0x1 << 28)


#define GEN_MASK(val, mask, sb)  (((val) << (sb)) & (mask))

/* some bits in ICR are reserved */

#define I2C_CLEAR_ALL_INTS	0x131f007f

/* first three msb bits are reserved */

#define IRQ_MASK(mask)		(mask & 0x1fffffff)

/* maximum threshold value */

#define MAX_I2C_FIFO_THRESHOLD	15


enum i2c_freq_mode {
	
I2C_FREQ_MODE_STANDARD,		/* up to 100 Kb/s */
	
I2C_FREQ_MODE_FAST,		/* up to 400 Kb/s */
	
I2C_FREQ_MODE_HIGH_SPEED,	/* up to 3.4 Mb/s */
	
I2C_FREQ_MODE_FAST_PLUS,	/* up to 1 Mb/s */
};

/**
 * struct i2c_vendor_data - per-vendor variations
 * @has_mtdws: variant has the MTDWS bit
 * @fifodepth: variant FIFO depth
 */

struct i2c_vendor_data {
	
bool has_mtdws;
	
u32 fifodepth;
};


enum i2c_status {
	
I2C_NOP,
	
I2C_ON_GOING,
	
I2C_OK,
	
I2C_ABORT
};

/* operation */

enum i2c_operation {
	
I2C_NO_OPERATION = 0xff,
	
I2C_WRITE = 0x00,
	
I2C_READ = 0x01
};

/**
 * struct i2c_nmk_client - client specific data
 * @slave_adr: 7-bit slave address
 * @count: no. bytes to be transferred
 * @buffer: client data buffer
 * @xfer_bytes: bytes transferred till now
 * @operation: current I2C operation
 */

struct i2c_nmk_client {
	
unsigned short		slave_adr;
	
unsigned long		count;
	
unsigned char		*buffer;
	
unsigned long		xfer_bytes;
	
enum i2c_operation	operation;
};

/**
 * struct nmk_i2c_dev - private data structure of the controller.
 * @vendor: vendor data for this variant.
 * @adev: parent amba device.
 * @adap: corresponding I2C adapter.
 * @irq: interrupt line for the controller.
 * @virtbase: virtual io memory area.
 * @clk: hardware i2c block clock.
 * @cli: holder of client specific data.
 * @clk_freq: clock frequency for the operation mode
 * @tft: Tx FIFO Threshold in bytes
 * @rft: Rx FIFO Threshold in bytes
 * @timeout Slave response timeout (ms)
 * @sm: speed mode
 * @stop: stop condition.
 * @xfer_complete: acknowledge completion for a I2C message.
 * @result: controller propogated result.
 */

struct nmk_i2c_dev {
	
struct i2c_vendor_data		*vendor;
	
struct amba_device		*adev;
	
struct i2c_adapter		adap;
	
int				irq;
	
void __iomem			*virtbase;
	
struct clk			*clk;
	
struct i2c_nmk_client		cli;
	
u32				clk_freq;
	
unsigned char			tft;
	
unsigned char			rft;
	
int				timeout;
	
enum i2c_freq_mode		sm;
	
int				stop;
	
struct completion		xfer_complete;
	
int				result;
};

/* controller's abort causes */

static const char *abort_causes[] = {
	"no ack received after address transmission",
	"no ack received during data phase",
	"ack received after xmission of master code",
	"master lost arbitration",
	"slave restarts",
	"slave reset",
	"overflow, maxsize is 2047 bytes",
};



static inline void i2c_set_bit(void __iomem *reg, u32 mask)
{
	writel(readl(reg) | mask, reg);
}

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static inline void i2c_clr_bit(void __iomem *reg, u32 mask)
{
	writel(readl(reg) & ~mask, reg);
}

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/**
 * flush_i2c_fifo() - This function flushes the I2C FIFO
 * @dev: private data of I2C Driver
 *
 * This function flushes the I2C Tx and Rx FIFOs. It returns
 * 0 on successful flushing of FIFO
 */


static int flush_i2c_fifo(struct nmk_i2c_dev *dev)
{

#define LOOP_ATTEMPTS 10
	int i;
	unsigned long timeout;

	/*
         * flush the transmit and receive FIFO. The flushing
         * operation takes several cycles before to be completed.
         * On the completion, the I2C internal logic clears these
         * bits, until then no one must access Tx, Rx FIFO and
         * should poll on these bits waiting for the completion.
         */
	writel((I2C_CR_FTX | I2C_CR_FRX), dev->virtbase + I2C_CR);

	for (i = 0; i < LOOP_ATTEMPTS; i++) {
		timeout = jiffies + dev->adap.timeout;

		while (!time_after(jiffies, timeout)) {
			if ((readl(dev->virtbase + I2C_CR) &
				(I2C_CR_FTX | I2C_CR_FRX)) == 0)
					return 0;
		}
	}

	dev_err(&dev->adev->dev,
		"flushing operation timed out giving up after %d attempts",
		LOOP_ATTEMPTS);

	return -ETIMEDOUT;
}

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/**
 * disable_all_interrupts() - Disable all interrupts of this I2c Bus
 * @dev: private data of I2C Driver
 */


static void disable_all_interrupts(struct nmk_i2c_dev *dev)
{
	u32 mask = IRQ_MASK(0);
	writel(mask, dev->virtbase + I2C_IMSCR);
}

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/**
 * clear_all_interrupts() - Clear all interrupts of I2C Controller
 * @dev: private data of I2C Driver
 */


static void clear_all_interrupts(struct nmk_i2c_dev *dev)
{
	u32 mask;
	mask = IRQ_MASK(I2C_CLEAR_ALL_INTS);
	writel(mask, dev->virtbase + I2C_ICR);
}

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/**
 * init_hw() - initialize the I2C hardware
 * @dev: private data of I2C Driver
 */


static int init_hw(struct nmk_i2c_dev *dev)
{
	int stat;

	stat = flush_i2c_fifo(dev);
	if (stat)
		goto exit;

	/* disable the controller */
	i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE);

	disable_all_interrupts(dev);

	clear_all_interrupts(dev);

	dev->cli.operation = I2C_NO_OPERATION;

exit:
	return stat;
}

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/* enable peripheral, master mode operation */

#define DEFAULT_I2C_REG_CR	((1 << 1) | I2C_CR_PE)

/**
 * load_i2c_mcr_reg() - load the MCR register
 * @dev: private data of controller
 * @flags: message flags
 */


static u32 load_i2c_mcr_reg(struct nmk_i2c_dev *dev, u16 flags)
{
	u32 mcr = 0;
	unsigned short slave_adr_3msb_bits;

	mcr |= GEN_MASK(dev->cli.slave_adr, I2C_MCR_A7, 1);

	if (unlikely(flags & I2C_M_TEN)) {
		/* 10-bit address transaction */
		mcr |= GEN_MASK(2, I2C_MCR_AM, 12);
		/*
                 * Get the top 3 bits.
                 * EA10 represents extended address in MCR. This includes
                 * the extension (MSB bits) of the 7 bit address loaded
                 * in A7
                 */
		slave_adr_3msb_bits = (dev->cli.slave_adr >> 7) & 0x7;

		mcr |= GEN_MASK(slave_adr_3msb_bits, I2C_MCR_EA10, 8);
	} else {
		/* 7-bit address transaction */
		mcr |= GEN_MASK(1, I2C_MCR_AM, 12);
	}

	/* start byte procedure not applied */
	mcr |= GEN_MASK(0, I2C_MCR_SB, 11);

	/* check the operation, master read/write? */
	if (dev->cli.operation == I2C_WRITE)
		mcr |= GEN_MASK(I2C_WRITE, I2C_MCR_OP, 0);
	else
		mcr |= GEN_MASK(I2C_READ, I2C_MCR_OP, 0);

	/* stop or repeated start? */
	if (dev->stop)
		mcr |= GEN_MASK(1, I2C_MCR_STOP, 14);
	else
		mcr &= ~(GEN_MASK(1, I2C_MCR_STOP, 14));

	mcr |= GEN_MASK(dev->cli.count, I2C_MCR_LENGTH, 15);

	return mcr;
}

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/**
 * setup_i2c_controller() - setup the controller
 * @dev: private data of controller
 */


static void setup_i2c_controller(struct nmk_i2c_dev *dev)
{
	u32 brcr1, brcr2;
	u32 i2c_clk, div;
	u32 ns;
	u16 slsu;

	writel(0x0, dev->virtbase + I2C_CR);
	writel(0x0, dev->virtbase + I2C_HSMCR);
	writel(0x0, dev->virtbase + I2C_TFTR);
	writel(0x0, dev->virtbase + I2C_RFTR);
	writel(0x0, dev->virtbase + I2C_DMAR);

	i2c_clk = clk_get_rate(dev->clk);

	/*
         * set the slsu:
         *
         * slsu defines the data setup time after SCL clock
         * stretching in terms of i2c clk cycles + 1 (zero means
         * "wait one cycle"), the needed setup time for the three
         * modes are 250ns, 100ns, 10ns respectively.
         *
         * As the time for one cycle T in nanoseconds is
         * T = (1/f) * 1000000000 =>
         * slsu = cycles / (1000000000 / f) + 1
         */
	ns = DIV_ROUND_UP_ULL(1000000000ULL, i2c_clk);
	switch (dev->sm) {
	case I2C_FREQ_MODE_FAST:
	case I2C_FREQ_MODE_FAST_PLUS:
		slsu = DIV_ROUND_UP(100, ns); /* Fast */
		break;
	case I2C_FREQ_MODE_HIGH_SPEED:
		slsu = DIV_ROUND_UP(10, ns); /* High */
		break;
	case I2C_FREQ_MODE_STANDARD:
	default:
		slsu = DIV_ROUND_UP(250, ns); /* Standard */
		break;
	}
	slsu += 1;

	dev_dbg(&dev->adev->dev, "calculated SLSU = %04x\n", slsu);
	writel(slsu << 16, dev->virtbase + I2C_SCR);

	/*
         * The spec says, in case of std. mode the divider is
         * 2 whereas it is 3 for fast and fastplus mode of
         * operation. TODO - high speed support.
         */
	div = (dev->clk_freq > 100000) ? 3 : 2;

	/*
         * generate the mask for baud rate counters. The controller
         * has two baud rate counters. One is used for High speed
         * operation, and the other is for std, fast mode, fast mode
         * plus operation. Currently we do not supprt high speed mode
         * so set brcr1 to 0.
         */
	brcr1 = 0 << 16;
	brcr2 = (i2c_clk/(dev->clk_freq * div)) & 0xffff;

	/* set the baud rate counter register */
	writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);

	/*
         * set the speed mode. Currently we support
         * only standard and fast mode of operation
         * TODO - support for fast mode plus (up to 1Mb/s)
         * and high speed (up to 3.4 Mb/s)
         */
	if (dev->sm > I2C_FREQ_MODE_FAST) {
		dev_err(&dev->adev->dev,
			"do not support this mode defaulting to std. mode\n");
		brcr2 = i2c_clk/(100000 * 2) & 0xffff;
		writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);
		writel(I2C_FREQ_MODE_STANDARD << 4,
				dev->virtbase + I2C_CR);
	}
	writel(dev->sm << 4, dev->virtbase + I2C_CR);

	/* set the Tx and Rx FIFO threshold */
	writel(dev->tft, dev->virtbase + I2C_TFTR);
	writel(dev->rft, dev->virtbase + I2C_RFTR);
}

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/**
 * read_i2c() - Read from I2C client device
 * @dev: private data of I2C Driver
 * @flags: message flags
 *
 * This function reads from i2c client device when controller is in
 * master mode. There is a completion timeout. If there is no transfer
 * before timeout error is returned.
 */


static int read_i2c(struct nmk_i2c_dev *dev, u16 flags)
{
	int status = 0;
	u32 mcr, irq_mask;
	unsigned long timeout;

	mcr = load_i2c_mcr_reg(dev, flags);
	writel(mcr, dev->virtbase + I2C_MCR);

	/* load the current CR value */
	writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR,
			dev->virtbase + I2C_CR);

	/* enable the controller */
	i2c_set_bit(dev->virtbase + I2C_CR, I2C_CR_PE);

	init_completion(&dev->xfer_complete);

	/* enable interrupts by setting the mask */
	irq_mask = (I2C_IT_RXFNF | I2C_IT_RXFF |
			I2C_IT_MAL | I2C_IT_BERR);

	if (dev->stop || !dev->vendor->has_mtdws)
		irq_mask |= I2C_IT_MTD;
	else
		irq_mask |= I2C_IT_MTDWS;

	irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask);

	writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask,
			dev->virtbase + I2C_IMSCR);

	timeout = wait_for_completion_timeout(
		&dev->xfer_complete, dev->adap.timeout);

	if (timeout == 0) {
		/* Controller timed out */
		dev_err(&dev->adev->dev, "read from slave 0x%x timed out\n",
				dev->cli.slave_adr);
		status = -ETIMEDOUT;
	}
	return status;
}

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static void fill_tx_fifo(struct nmk_i2c_dev *dev, int no_bytes)
{
	int count;

	for (count = (no_bytes - 2);
			(count > 0) &&
			(dev->cli.count != 0);
			count--) {
		/* write to the Tx FIFO */
		writeb(*dev->cli.buffer,
			dev->virtbase + I2C_TFR);
		dev->cli.buffer++;
		dev->cli.count--;
		dev->cli.xfer_bytes++;
	}

}

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/**
 * write_i2c() - Write data to I2C client.
 * @dev: private data of I2C Driver
 * @flags: message flags
 *
 * This function writes data to I2C client
 */


static int write_i2c(struct nmk_i2c_dev *dev, u16 flags)
{
	u32 status = 0;
	u32 mcr, irq_mask;
	unsigned long timeout;

	mcr = load_i2c_mcr_reg(dev, flags);

	writel(mcr, dev->virtbase + I2C_MCR);

	/* load the current CR value */
	writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR,
			dev->virtbase + I2C_CR);

	/* enable the controller */
	i2c_set_bit(dev->virtbase + I2C_CR , I2C_CR_PE);

	init_completion(&dev->xfer_complete);

	/* enable interrupts by settings the masks */
	irq_mask = (I2C_IT_TXFOVR | I2C_IT_MAL | I2C_IT_BERR);

	/* Fill the TX FIFO with transmit data */
	fill_tx_fifo(dev, MAX_I2C_FIFO_THRESHOLD);

	if (dev->cli.count != 0)
		irq_mask |= I2C_IT_TXFNE;

	/*
         * check if we want to transfer a single or multiple bytes, if so
         * set the MTDWS bit (Master Transaction Done Without Stop)
         * to start repeated start operation
         */
	if (dev->stop || !dev->vendor->has_mtdws)
		irq_mask |= I2C_IT_MTD;
	else
		irq_mask |= I2C_IT_MTDWS;

	irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask);

	writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask,
			dev->virtbase + I2C_IMSCR);

	timeout = wait_for_completion_timeout(
		&dev->xfer_complete, dev->adap.timeout);

	if (timeout == 0) {
		/* Controller timed out */
		dev_err(&dev->adev->dev, "write to slave 0x%x timed out\n",
				dev->cli.slave_adr);
		status = -ETIMEDOUT;
	}

	return status;
}

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srinidhi kasagar
174
77.33%
2
18.18%
virupax sadashivpetimath
virupax sadashivpetimath
40
17.78%
5
45.45%
linus walleij
linus walleij
7
3.11%
1
9.09%
nicholas mc guire
nicholas mc guire
2
0.89%
1
9.09%
alessandro rubini
alessandro rubini
1
0.44%
1
9.09%
wolfram sang
wolfram sang
1
0.44%
1
9.09%
Total
225
100.00%
11
100.00%

/**
 * nmk_i2c_xfer_one() - transmit a single I2C message
 * @dev: device with a message encoded into it
 * @flags: message flags
 */


static int nmk_i2c_xfer_one(struct nmk_i2c_dev *dev, u16 flags)
{
	int status;

	if (flags & I2C_M_RD) {
		/* read operation */
		dev->cli.operation = I2C_READ;
		status = read_i2c(dev, flags);
	} else {
		/* write operation */
		dev->cli.operation = I2C_WRITE;
		status = write_i2c(dev, flags);
	}

	if (status || (dev->result)) {
		u32 i2c_sr;
		u32 cause;

		i2c_sr = readl(dev->virtbase + I2C_SR);
		/*
                 * Check if the controller I2C operation status
                 * is set to ABORT(11b).
                 */
		if (((i2c_sr >> 2) & 0x3) == 0x3) {
			/* get the abort cause */
			cause =	(i2c_sr >> 4) & 0x7;
			dev_err(&dev->adev->dev, "%s\n",
				cause >= ARRAY_SIZE(abort_causes) ?
				"unknown reason" :
				abort_causes[cause]);
		}

		(void) init_hw(dev);

		status = status ? status : dev->result;
	}

	return status;
}

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linus walleij
163
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1
33.33%
virupax sadashivpetimath
virupax sadashivpetimath
4
2.38%
1
33.33%
alessandro rubini
alessandro rubini
1
0.60%
1
33.33%
Total
168
100.00%
3
100.00%

/**
 * nmk_i2c_xfer() - I2C transfer function used by kernel framework
 * @i2c_adap: Adapter pointer to the controller
 * @msgs: Pointer to data to be written.
 * @num_msgs: Number of messages to be executed
 *
 * This is the function called by the generic kernel i2c_transfer()
 * or i2c_smbus...() API calls. Note that this code is protected by the
 * semaphore set in the kernel i2c_transfer() function.
 *
 * NOTE:
 * READ TRANSFER : We impose a restriction of the first message to be the
 *              index message for any read transaction.
 *              - a no index is coded as '0',
 *              - 2byte big endian index is coded as '3'
 *              !!! msg[0].buf holds the actual index.
 *              This is compatible with generic messages of smbus emulator
 *              that send a one byte index.
 *              eg. a I2C transation to read 2 bytes from index 0
 *                      idx = 0;
 *                      msg[0].addr = client->addr;
 *                      msg[0].flags = 0x0;
 *                      msg[0].len = 1;
 *                      msg[0].buf = &idx;
 *
 *                      msg[1].addr = client->addr;
 *                      msg[1].flags = I2C_M_RD;
 *                      msg[1].len = 2;
 *                      msg[1].buf = rd_buff
 *                      i2c_transfer(adap, msg, 2);
 *
 * WRITE TRANSFER : The I2C standard interface interprets all data as payload.
 *              If you want to emulate an SMBUS write transaction put the
 *              index as first byte(or first and second) in the payload.
 *              eg. a I2C transation to write 2 bytes from index 1
 *                      wr_buff[0] = 0x1;
 *                      wr_buff[1] = 0x23;
 *                      wr_buff[2] = 0x46;
 *                      msg[0].flags = 0x0;
 *                      msg[0].len = 3;
 *                      msg[0].buf = wr_buff;
 *                      i2c_transfer(adap, msg, 1);
 *
 * To read or write a block of data (multiple bytes) using SMBUS emulation
 * please use the i2c_smbus_read_i2c_block_data()
 * or i2c_smbus_write_i2c_block_data() API
 */


static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
		struct i2c_msg msgs[], int num_msgs)
{
	int status = 0;
	int i;
	struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
	int j;

	pm_runtime_get_sync(&dev->adev->dev);

	/* Attempt three times to send the message queue */
	for (j = 0; j < 3; j++) {
		/* setup the i2c controller */
		setup_i2c_controller(dev);

		for (i = 0; i < num_msgs; i++) {
			dev->cli.slave_adr	= msgs[i].addr;
			dev->cli.buffer		= msgs[i].buf;
			dev->cli.count		= msgs[i].len;
			dev->stop = (i < (num_msgs - 1)) ? 0 : 1;
			dev->result = 0;

			status = nmk_i2c_xfer_one(dev, msgs[i].flags);
			if (status != 0)
				break;
		}
		if (status == 0)
			break;
	}

	pm_runtime_put_sync(&dev->adev->dev);

	/* return the no. messages processed */
	if (status)
		return status;
	else
		return num_msgs;
}

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srinidhi kasagar
142
71.00%
1
14.29%
virupax sadashivpetimath
virupax sadashivpetimath
27
13.50%
2
28.57%
rabin vincent
rabin vincent
18
9.00%
1
14.29%
linus walleij
linus walleij
9
4.50%
1
14.29%
alessandro rubini
alessandro rubini
2
1.00%
1
14.29%
ulf hansson
ulf hansson
2
1.00%
1
14.29%
Total
200
100.00%
7
100.00%

/**
 * disable_interrupts() - disable the interrupts
 * @dev: private data of controller
 * @irq: interrupt number
 */


static int disable_interrupts(struct nmk_i2c_dev *dev, u32 irq)
{
	irq = IRQ_MASK(irq);
	writel(readl(dev->virtbase + I2C_IMSCR) & ~(I2C_CLEAR_ALL_INTS & irq),
			dev->virtbase + I2C_IMSCR);
	return 0;
}

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49
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/**
 * i2c_irq_handler() - interrupt routine
 * @irq: interrupt number
 * @arg: data passed to the handler
 *
 * This is the interrupt handler for the i2c driver. Currently
 * it handles the major interrupts like Rx & Tx FIFO management
 * interrupts, master transaction interrupts, arbitration and
 * bus error interrupts. The rest of the interrupts are treated as
 * unhandled.
 */


static irqreturn_t i2c_irq_handler(int irq, void *arg)
{
	struct nmk_i2c_dev *dev = arg;
	u32 tft, rft;
	u32 count;
	u32 misr, src;

	/* load Tx FIFO and Rx FIFO threshold values */
	tft = readl(dev->virtbase + I2C_TFTR);
	rft = readl(dev->virtbase + I2C_RFTR);

	/* read interrupt status register */
	misr = readl(dev->virtbase + I2C_MISR);

	src = __ffs(misr);
	switch ((1 << src)) {

	/* Transmit FIFO nearly empty interrupt */
	case I2C_IT_TXFNE:
	{
		if (dev->cli.operation == I2C_READ) {
			/*
                         * in read operation why do we care for writing?
                         * so disable the Transmit FIFO interrupt
                         */
			disable_interrupts(dev, I2C_IT_TXFNE);
		} else {
			fill_tx_fifo(dev, (MAX_I2C_FIFO_THRESHOLD - tft));
			/*
                         * if done, close the transfer by disabling the
                         * corresponding TXFNE interrupt
                         */
			if (dev->cli.count == 0)
				disable_interrupts(dev,	I2C_IT_TXFNE);
		}
	}
	break;

	/*
         * Rx FIFO nearly full interrupt.
         * This is set when the numer of entries in Rx FIFO is
         * greater or equal than the threshold value programmed
         * in RFT
         */
	case I2C_IT_RXFNF:
		for (count = rft; count > 0; count--) {
			/* Read the Rx FIFO */
			*dev->cli.buffer = readb(dev->virtbase + I2C_RFR);
			dev->cli.buffer++;
		}
		dev->cli.count -= rft;
		dev->cli.xfer_bytes += rft;
		break;

	/* Rx FIFO full */
	case I2C_IT_RXFF:
		for (count = MAX_I2C_FIFO_THRESHOLD; count > 0; count--) {
			*dev->cli.buffer = readb(dev->virtbase + I2C_RFR);
			dev->cli.buffer++;
		}
		dev->cli.count -= MAX_I2C_FIFO_THRESHOLD;
		dev->cli.xfer_bytes += MAX_I2C_FIFO_THRESHOLD;
		break;

	/* Master Transaction Done with/without stop */
	case I2C_IT_MTD:
	case I2C_IT_MTDWS:
		if (dev->cli.operation == I2C_READ) {
			while (!(readl(dev->virtbase + I2C_RISR)
				 & I2C_IT_RXFE)) {
				if (dev->cli.count == 0)
					break;
				*dev->cli.buffer =
					readb(dev->virtbase + I2C_RFR);
				dev->cli.buffer++;
				dev->cli.count--;
				dev->cli.xfer_bytes++;
			}
		}

		disable_all_interrupts(dev);
		clear_all_interrupts(dev);

		if (dev->cli.count) {
			dev->result = -EIO;
			dev_err(&dev->adev->dev,
				"%lu bytes still remain to be xfered\n",
				dev->cli.count);
			(void) init_hw(dev);
		}
		complete(&dev->xfer_complete);

		break;

	/* Master Arbitration lost interrupt */
	case I2C_IT_MAL:
		dev->result = -EIO;
		(void) init_hw(dev);

		i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MAL);
		complete(&dev->xfer_complete);

		break;

	/*
         * Bus Error interrupt.
         * This happens when an unexpected start/stop condition occurs
         * during the transaction.
         */
	case I2C_IT_BERR:
		dev->result = -EIO;
		/* get the status */
		if (((readl(dev->virtbase + I2C_SR) >> 2) & 0x3) == I2C_ABORT)
			(void) init_hw(dev);

		i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_BERR);
		complete(&dev->xfer_complete);

		break;

	/*
         * Tx FIFO overrun interrupt.
         * This is set when a write operation in Tx FIFO is performed and
         * the Tx FIFO is full.
         */
	case I2C_IT_TXFOVR:
		dev->result = -EIO;
		(void) init_hw(dev);

		dev_err(&dev->adev->dev, "Tx Fifo Over run\n");
		complete(&dev->xfer_complete);

		break;

	/* unhandled interrupts by this driver - TODO*/
	case I2C_IT_TXFE:
	case I2C_IT_TXFF:
	case I2C_IT_RXFE:
	case I2C_IT_RFSR:
	case I2C_IT_RFSE:
	case I2C_IT_WTSR:
	case I2C_IT_STD:
		dev_err(&dev->adev->dev, "unhandled Interrupt\n");
		break;
	default:
		dev_err(&dev->adev->dev, "spurious Interrupt..\n");
		break;
	}

	return IRQ_HANDLED;
}

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srinidhi kasagar
srinidhi kasagar
584
97.01%
1
12.50%
virupax sadashivpetimath
virupax sadashivpetimath
10
1.66%
3
37.50%
alessandro rubini
alessandro rubini
4
0.66%
1
12.50%
rabin vincent
rabin vincent
2
0.33%
1
12.50%
jonas aberg
jonas aberg
1
0.17%
1
12.50%
wolfram sang
wolfram sang
1
0.17%
1
12.50%
Total
602
100.00%
8
100.00%

#ifdef CONFIG_PM_SLEEP


static int nmk_i2c_suspend_late(struct device *dev)
{
	int ret;

	ret = pm_runtime_force_suspend(dev);
	if (ret)
		return ret;

	pinctrl_pm_select_sleep_state(dev);
	return 0;
}

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ulf hansson
ulf hansson
18
50.00%
2
33.33%
jonas aberg
jonas aberg
7
19.44%
1
16.67%
rabin vincent
rabin vincent
6
16.67%
1
16.67%
patrice chotard
patrice chotard
4
11.11%
1
16.67%
linus walleij
linus walleij
1
2.78%
1
16.67%
Total
36
100.00%
6
100.00%



static int nmk_i2c_resume_early(struct device *dev)
{
	return pm_runtime_force_resume(dev);
}
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rabin vincent
rabin vincent
9
52.94%
1
20.00%
patrice chotard
patrice chotard
3
17.65%
1
20.00%
ulf hansson
ulf hansson
3
17.65%
2
40.00%
jonas aberg
jonas aberg
2
11.76%
1
20.00%
Total
17
100.00%
5
100.00%

#endif

#ifdef CONFIG_PM


static int nmk_i2c_runtime_suspend(struct device *dev)
{
	struct amba_device *adev = to_amba_device(dev);
	struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);

	clk_disable_unprepare(nmk_i2c->clk);
	pinctrl_pm_select_idle_state(dev);
	return 0;
}

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ulf hansson
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46
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1
100.00%



static int nmk_i2c_runtime_resume(struct device *dev)
{
	struct amba_device *adev = to_amba_device(dev);
	struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);
	int ret;

	ret = clk_prepare_enable(nmk_i2c->clk);
	if (ret) {
		dev_err(dev, "can't prepare_enable clock\n");
		return ret;
	}

	pinctrl_pm_select_default_state(dev);

	ret = init_hw(nmk_i2c);
	if (ret) {
		clk_disable_unprepare(nmk_i2c->clk);
		pinctrl_pm_select_idle_state(dev);
	}

	return ret;
}
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92
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#endif


static const struct dev_pm_ops nmk_i2c_pm = {
	SET_LATE_SYSTEM_SLEEP_PM_OPS(nmk_i2c_suspend_late, nmk_i2c_resume_early)
	SET_RUNTIME_PM_OPS(nmk_i2c_runtime_suspend,
			nmk_i2c_runtime_resume,
			NULL)
};



static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
}

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srinidhi kasagar
16
84.21%
1
33.33%
virupax sadashivpetimath
virupax sadashivpetimath
2
10.53%
1
33.33%
linus walleij
linus walleij
1
5.26%
1
33.33%
Total
19
100.00%
3
100.00%


static const struct i2c_algorithm nmk_i2c_algo = {
	.master_xfer	= nmk_i2c_xfer,
	.functionality	= nmk_i2c_functionality
};



static void nmk_i2c_of_probe(struct device_node *np,
			     struct nmk_i2c_dev *nmk)
{
	/* Default to 100 kHz if no frequency is given in the node */
	if (of_property_read_u32(np, "clock-frequency", &nmk->clk_freq))
		nmk->clk_freq = 100000;

	/* This driver only supports 'standard' and 'fast' modes of operation. */
	if (nmk->clk_freq <= 100000)
		nmk->sm = I2C_FREQ_MODE_STANDARD;
	else
		nmk->sm = I2C_FREQ_MODE_FAST;
	nmk->tft = 1; /* Tx FIFO threshold */
	nmk->rft = 8; /* Rx FIFO threshold */
	nmk->timeout = 200; /* Slave response timeout(ms) */
}

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36
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1
50.00%
Total
80
100.00%
2
100.00%



static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
{
	int ret = 0;
	struct device_node *np = adev->dev.of_node;
	struct nmk_i2c_dev	*dev;
	struct i2c_adapter *adap;
	struct i2c_vendor_data *vendor = id->data;
	u32 max_fifo_threshold = (vendor->fifodepth / 2) - 1;

	dev = devm_kzalloc(&adev->dev, sizeof(struct nmk_i2c_dev), GFP_KERNEL);
	if (!dev) {
		dev_err(&adev->dev, "cannot allocate memory\n");
		ret = -ENOMEM;
		goto err_no_mem;
	}
	dev->vendor = vendor;
	dev->adev = adev;
	nmk_i2c_of_probe(np, dev);

	if (dev->tft > max_fifo_threshold) {
		dev_warn(&adev->dev, "requested TX FIFO threshold %u, adjusted down to %u\n",
			 dev->tft, max_fifo_threshold);
		dev->tft = max_fifo_threshold;
	}

	if (dev->rft > max_fifo_threshold) {
		dev_warn(&adev->dev, "requested RX FIFO threshold %u, adjusted down to %u\n",
			dev->rft, max_fifo_threshold);
		dev->rft = max_fifo_threshold;
	}

	amba_set_drvdata(adev, dev);

	dev->virtbase = devm_ioremap(&adev->dev, adev->res.start,
				resource_size(&adev->res));
	if (!dev->virtbase) {
		ret = -ENOMEM;
		goto err_no_mem;
	}

	dev->irq = adev->irq[0];
	ret = devm_request_irq(&adev->dev, dev->irq, i2c_irq_handler, 0,
				DRIVER_NAME, dev);
	if (ret) {
		dev_err(&adev->dev, "cannot claim the irq %d\n", dev->irq);
		goto err_no_mem;
	}

	pm_suspend_ignore_children(&adev->dev, true);

	dev->clk = devm_clk_get(&adev->dev, NULL);
	if (IS_ERR(dev->clk)) {
		dev_err(&adev->dev, "could not get i2c clock\n");
		ret = PTR_ERR(dev->clk);
		goto err_no_mem;
	}

	ret = clk_prepare_enable(dev->clk);
	if (ret) {
		dev_err(&adev->dev, "can't prepare_enable clock\n");
		goto err_no_mem;
	}

	init_hw(dev);

	adap = &dev->adap;
	adap->dev.of_node = np;
	adap->dev.parent = &adev->dev;
	adap->owner = THIS_MODULE;
	adap->class = I2C_CLASS_DEPRECATED;
	adap->algo = &nmk_i2c_algo;
	adap->timeout = msecs_to_jiffies(dev->timeout);
	snprintf(adap->name, sizeof(adap->name),
		 "Nomadik I2C at %pR", &adev->res);

	i2c_set_adapdata(adap, dev);

	dev_info(&adev->dev,
		 "initialize %s on virtual base %p\n",
		 adap->name, dev->virtbase);

	ret = i2c_add_adapter(adap);
	if (ret) {
		dev_err(&adev->dev, "failed to add adapter\n");
		goto err_no_adap;
	}

	pm_runtime_put(&adev->dev);

	return 0;

 err_no_adap:
	clk_disable_unprepare(dev->clk);
 err_no_mem:

	return ret;
}

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srinidhi kasagar
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5.56%
linus walleij
linus walleij
135
25.00%
4
22.22%
ulf hansson
ulf hansson
66
12.22%
3
16.67%
lee jones
lee jones
49
9.07%
1
5.56%
alessandro rubini
alessandro rubini
39
7.22%
1
5.56%
virupax sadashivpetimath
virupax sadashivpetimath
10
1.85%
2
11.11%
rabin vincent
rabin vincent
9
1.67%
1
5.56%
jonas aberg
jonas aberg
3
0.56%
2
11.11%
patrice chotard
patrice chotard
2
0.37%
1
5.56%
yong zhang
yong zhang
1
0.19%
1
5.56%
wolfram sang
wolfram sang
1
0.19%
1
5.56%
Total
540
100.00%
18
100.00%



static int nmk_i2c_remove(struct amba_device *adev)
{
	struct resource *res = &adev->res;
	struct nmk_i2c_dev *dev = amba_get_drvdata(adev);

	i2c_del_adapter(&dev->adap);
	flush_i2c_fifo(dev);
	disable_all_interrupts(dev);
	clear_all_interrupts(dev);
	/* disable the controller */
	i2c_clr_bit(dev->virtbase + I2C_CR, I2C_CR_PE);
	clk_disable_unprepare(dev->clk);
	if (res)
		release_mem_region(res->start, resource_size(res));

	return 0;
}

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srinidhi kasagar
55
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1
25.00%
rabin vincent
rabin vincent
22
23.91%
1
25.00%
alessandro rubini
alessandro rubini
8
8.70%
1
25.00%
ulf hansson
ulf hansson
7
7.61%
1
25.00%
Total
92
100.00%
4
100.00%


static struct i2c_vendor_data vendor_stn8815 = {
	.has_mtdws = false,
	.fifodepth = 16, /* Guessed from TFTR/RFTR = 7 */
};


static struct i2c_vendor_data vendor_db8500 = {
	.has_mtdws = true,
	.fifodepth = 32, /* Guessed from TFTR/RFTR = 15 */
};


static struct amba_id nmk_i2c_ids[] = {
	{
		.id	= 0x00180024,
		.mask	= 0x00ffffff,
		.data	= &vendor_stn8815,
        },
	{
		.id	= 0x00380024,
		.mask	= 0x00ffffff,
		.data	= &vendor_db8500,
        },
	{},
};

MODULE_DEVICE_TABLE(amba, nmk_i2c_ids);


static struct amba_driver nmk_i2c_driver = {
	.drv = {
		.owner = THIS_MODULE,
		.name = DRIVER_NAME,
		.pm = &nmk_i2c_pm,
        },
	.id_table = nmk_i2c_ids,
	.probe = nmk_i2c_probe,
	.remove = nmk_i2c_remove,
};



static int __init nmk_i2c_init(void)
{
	return amba_driver_register(&nmk_i2c_driver);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
srinidhi kasagar
srinidhi kasagar
15
93.75%
1
50.00%
alessandro rubini
alessandro rubini
1
6.25%
1
50.00%
Total
16
100.00%
2
100.00%



static void __exit nmk_i2c_exit(void)
{
	amba_driver_unregister(&nmk_i2c_driver);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
srinidhi kasagar
srinidhi kasagar
14
93.33%
1
50.00%
alessandro rubini
alessandro rubini
1
6.67%
1
50.00%
Total
15
100.00%
2
100.00%


subsys_initcall(nmk_i2c_init);

module_exit(nmk_i2c_exit);

MODULE_AUTHOR("Sachin Verma, Srinidhi KASAGAR");
MODULE_DESCRIPTION("Nomadik/Ux500 I2C driver");
MODULE_LICENSE("GPL");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
srinidhi kasagar
srinidhi kasagar
2621
64.73%
2
4.65%
linus walleij
linus walleij
560
13.83%
10
23.26%
virupax sadashivpetimath
virupax sadashivpetimath
269
6.64%
9
20.93%
ulf hansson
ulf hansson
255
6.30%
6
13.95%
alessandro rubini
alessandro rubini
113
2.79%
1
2.33%
lee jones
lee jones
96
2.37%
1
2.33%
rabin vincent
rabin vincent
83
2.05%
3
6.98%
jonas aberg
jonas aberg
26
0.64%
2
4.65%
patrice chotard
patrice chotard
10
0.25%
1
2.33%
nicholas mc guire
nicholas mc guire
5
0.12%
2
4.65%
wolfram sang
wolfram sang
4
0.10%
2
4.65%
tejun heo
tejun heo
3
0.07%
1
2.33%
lucas de marchi
lucas de marchi
2
0.05%
1
2.33%
rafael j. wysocki
rafael j. wysocki
1
0.02%
1
2.33%
yong zhang
yong zhang
1
0.02%
1
2.33%
Total
4049
100.00%
43
100.00%
  
Directory: drivers/i2c/busses

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