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Commit c57db709 authored by Jan Glauber's avatar Jan Glauber Committed by Wolfram Sang
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i2c: octeon: Introduce helper functions for register access 



Add helper functions for control, data and status register access.
This simplifies the code and makes the purpose of the register
access clearer.

Signed-off-by: default avatarJan Glauber <jglauber@cavium.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 9cb9480e

drivers/i2c/busses/i2c-octeon.c

+31 −25
Original line number Diff line number Diff line
@@ -97,6 +97,11 @@ static void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data) 
	} while ((tmp & SW_TWSI_V) != 0);

}



#define octeon_i2c_ctl_write(i2c, val)					\

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val)

#define octeon_i2c_data_write(i2c, val)					\

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val)



/**

 * octeon_i2c_reg_read - read lower bits of an I2C core register

 * @i2c: The struct octeon_i2c
@@ -118,6 +123,13 @@ static u8 octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg) 
	return tmp & 0xFF;

}



#define octeon_i2c_ctl_read(i2c)					\

	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL)

#define octeon_i2c_data_read(i2c)					\

	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA)

#define octeon_i2c_stat_read(i2c)					\

	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT)



/**

 * octeon_i2c_write_int - write the TWSI_INT register

 * @i2c: The struct octeon_i2c
@@ -189,7 +201,7 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id) 


static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)

{

	return (octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL) & TWSI_CTL_IFLG) != 0;

	return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG) != 0;

}



/**
@@ -262,14 +274,14 @@ static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c) 
	int tries;



	/* disable high level controller, enable bus access */

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);

	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);



	/* reset controller */

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_RST, 0);



	for (tries = 10; tries; tries--) {

		udelay(1);

		status = octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT);

		status = octeon_i2c_stat_read(i2c);

		if (status == STAT_IDLE)

			return 0;

	}
@@ -288,27 +300,25 @@ static int octeon_i2c_start(struct octeon_i2c *i2c) 
	int result;

	u8 data;



	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL,

			    TWSI_CTL_ENAB | TWSI_CTL_STA);

	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);



	result = octeon_i2c_wait(i2c);

	if (result) {

		if (octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT) == STAT_IDLE) {

		if (octeon_i2c_stat_read(i2c) == STAT_IDLE) {

			/*

			 * Controller refused to send start flag May

			 * be a client is holding SDA low - let's try

			 * to free it.

			 */

			octeon_i2c_unblock(i2c);

			octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL,

					    TWSI_CTL_ENAB | TWSI_CTL_STA);

			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);

			result = octeon_i2c_wait(i2c);

		}

		if (result)

			return result;

	}



	data = octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT);

	data = octeon_i2c_stat_read(i2c);

	if ((data != STAT_START) && (data != STAT_RSTART)) {

		dev_err(i2c->dev, "%s: bad status (0x%x)\n", __func__, data);

		return -EIO;
@@ -320,8 +330,7 @@ static int octeon_i2c_start(struct octeon_i2c *i2c) 
/* send STOP to the bus */

static void octeon_i2c_stop(struct octeon_i2c *i2c)

{

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL,

			    TWSI_CTL_ENAB | TWSI_CTL_STP);

	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STP);

}



/**
@@ -345,15 +354,15 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target, 
	if (result)

		return result;



	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);

	octeon_i2c_data_write(i2c, target << 1);

	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);



	result = octeon_i2c_wait(i2c);

	if (result)

		return result;



	for (i = 0; i < length; i++) {

		tmp = octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT);

		tmp = octeon_i2c_stat_read(i2c);



		if ((tmp != STAT_TXADDR_ACK) && (tmp != STAT_TXDATA_ACK)) {

			dev_err(i2c->dev,
@@ -362,8 +371,8 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target, 
			return -EIO;

		}



		octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);

		octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);

		octeon_i2c_data_write(i2c, data[i]);

		octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);



		result = octeon_i2c_wait(i2c);

		if (result)
@@ -398,16 +407,15 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target, 
	if (result)

		return result;



	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);

	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);

	octeon_i2c_data_write(i2c, (target << 1) | 1);

	octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);



	result = octeon_i2c_wait(i2c);

	if (result)

		return result;



	for (i = 0; i < length; i++) {

		tmp = octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT);



		tmp = octeon_i2c_stat_read(i2c);

		if ((tmp != STAT_RXDATA_ACK) && (tmp != STAT_RXADDR_ACK)) {

			dev_err(i2c->dev,

				"%s: bad status before read (0x%x)\n",
@@ -416,17 +424,15 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target, 
		}



		if (i + 1 < length)

			octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL,

					    TWSI_CTL_ENAB | TWSI_CTL_AAK);

			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_AAK);

		else

			octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL,

					    TWSI_CTL_ENAB);

			octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);



		result = octeon_i2c_wait(i2c);

		if (result)

			return result;



		data[i] = octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA);

		data[i] = octeon_i2c_data_read(i2c);

		if (recv_len && i == 0) {

			if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {

				dev_err(i2c->dev,