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Commit 47dcd016 authored by Shubhrajyoti D's avatar Shubhrajyoti D Committed by Wolfram Sang
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i2c: omap: Fix the revision register read 



The revision register on OMAP4 is a 16-bit lo and a 16-bit
hi. Currently the driver reads only the lower 8-bits.
Fix the same by preventing the truncating of the rev register
for OMAP4.

Also use the scheme bit ie bit-14 of the hi register to know if it
is OMAP_I2C_IP_VERSION_2.

On platforms previous to OMAP4 the offset 0x04 is IE register whose
bit-14 reset value is 0, the code uses the same to its advantage.

Also since the omap_i2c_read_reg uses reg_map_ip_* a raw_readw is done
to fetch the revision register.

The dev->regs is populated after reading the rev_hi. A NULL check
has been added in the resume handler to prevent the access before
the setting of the regs.

Signed-off-by: default avatarShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent 2d4b4520

drivers/i2c/busses/i2c-omap.c

+48 −13
Original line number Diff line number Diff line
@@ -49,9 +49,10 @@ 
#define OMAP_I2C_OMAP1_REV_2		0x20



/* I2C controller revisions present on specific hardware */

#define OMAP_I2C_REV_ON_2430		0x36

#define OMAP_I2C_REV_ON_3430_3530	0x3C

#define OMAP_I2C_REV_ON_3630_4430	0x40

#define OMAP_I2C_REV_ON_2430		0x00000036

#define OMAP_I2C_REV_ON_3430_3530	0x0000003C

#define OMAP_I2C_REV_ON_3630		0x00000040

#define OMAP_I2C_REV_ON_4430_PLUS	0x50400002



/* timeout waiting for the controller to respond */

#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
@@ -203,7 +204,7 @@ struct omap_i2c_dev { 
						 * fifo_size==0 implies no fifo

						 * if set, should be trsh+1

						 */

	u8			rev;

	u32			rev;

	unsigned		b_hw:1;		/* bad h/w fixes */

	unsigned		receiver:1;	/* true when we're in receiver mode */

	u16			iestate;	/* Saved interrupt register */
@@ -493,7 +494,7 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx) 


	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);



	if (dev->rev < OMAP_I2C_REV_ON_3630_4430)

	if (dev->rev < OMAP_I2C_REV_ON_3630)

		dev->b_hw = 1; /* Enable hardware fixes */



	/* calculate wakeup latency constraint for MPU */
@@ -1051,6 +1052,16 @@ static const struct of_device_id omap_i2c_of_match[] = { 
MODULE_DEVICE_TABLE(of, omap_i2c_of_match);

#endif



#define OMAP_I2C_SCHEME(rev)		((rev & 0xc000) >> 14)



#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)

#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)



#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)

#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)

#define OMAP_I2C_SCHEME_0		0

#define OMAP_I2C_SCHEME_1		1



static int __devinit

omap_i2c_probe(struct platform_device *pdev)

{
@@ -1063,6 +1074,8 @@ omap_i2c_probe(struct platform_device *pdev) 
	const struct of_device_id *match;

	int irq;

	int r;

	u32 rev;

	u16 minor, major;



	/* NOTE: driver uses the static register mapping */

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1127,11 +1140,6 @@ omap_i2c_probe(struct platform_device *pdev) 


	dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;



	if (dev->dtrev == OMAP_I2C_IP_VERSION_2)

		dev->regs = (u8 *)reg_map_ip_v2;

	else

		dev->regs = (u8 *)reg_map_ip_v1;



	pm_runtime_enable(dev->dev);

	pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT);

	pm_runtime_use_autosuspend(dev->dev);
@@ -1140,7 +1148,31 @@ omap_i2c_probe(struct platform_device *pdev) 
	if (IS_ERR_VALUE(r))

		goto err_free_mem;



	dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;

	/*

	 * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.

	 * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.

	 * Also since the omap_i2c_read_reg uses reg_map_ip_* a

	 * raw_readw is done.

	 */

	rev = __raw_readw(dev->base + 0x04);



	switch (OMAP_I2C_SCHEME(rev)) {

	case OMAP_I2C_SCHEME_0:

		dev->regs = (u8 *)reg_map_ip_v1;

		dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG);

		minor = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev);

		major = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev);

		break;

	case OMAP_I2C_SCHEME_1:

		/* FALLTHROUGH */

	default:

		dev->regs = (u8 *)reg_map_ip_v2;

		rev = (rev << 16) |

			omap_i2c_read_reg(dev, OMAP_I2C_IP_V2_REVNB_LO);

		minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);

		major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);

		dev->rev = rev;

	}



	dev->errata = 0;
@@ -1165,7 +1197,7 @@ omap_i2c_probe(struct platform_device *pdev) 


		dev->fifo_size = (dev->fifo_size / 2);



		if (dev->rev < OMAP_I2C_REV_ON_3630_4430)

		if (dev->rev < OMAP_I2C_REV_ON_3630)

			dev->b_hw = 1; /* Enable hardware fixes */



		/* calculate wakeup latency constraint for MPU */
@@ -1209,7 +1241,7 @@ omap_i2c_probe(struct platform_device *pdev) 
	}



	dev_info(dev->dev, "bus %d rev%d.%d.%d at %d kHz\n", adap->nr,

		 dev->dtrev, dev->rev >> 4, dev->rev & 0xf, dev->speed);

		 dev->dtrev, major, minor, dev->speed);



	of_i2c_register_devices(adap);
@@ -1275,6 +1307,9 @@ static int omap_i2c_runtime_resume(struct device *dev) 
	struct platform_device *pdev = to_platform_device(dev);

	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);



	if (!_dev->regs)

		return 0;



	if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {

		omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0);

		omap_i2c_write_reg(_dev, OMAP_I2C_PSC_REG, _dev->pscstate);