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i2c: omap: Fix the revision register read

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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: Shubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Shubhrajyoti D 2012-11-05 17:53:36 +05:30 committed by Wolfram Sang
parent 2d4b4520a5
commit 47dcd0161a
1 changed files with 48 additions and 13 deletions
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61
drivers/i2c/busses/i2c-omap.c
View file

@ -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);