NOT FOR UPSTREAM The patch checks if IP reset during probe could bring I2C bus to a free state on omap2430 - omap3530 boards.
I guess, IP hold one of I2C lines in a low state. I guess, u-boot haven't sent a stop condition. The patch is rebased on branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux (6e79807443cba7397cd855ed29d6faba51d4c893) Signed-off-by: Alexander Kochetkov <[email protected]> Reported-by: Kevin Hilman <[email protected]> Tested-by: Kevin Hilman <[email protected]> --- drivers/i2c/busses/i2c-omap.c | 41 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 39 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 4563200..865c9a1 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -282,6 +282,26 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) (i2c_dev->regs[reg] << i2c_dev->reg_shift)); } +static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *dev); + +static inline void +omap_i2c_dump_state(const char *func, int line, struct omap_i2c_dev *dev, const char *msg) +{ + u16 systest = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + dev_info(dev->dev, "%s: STAT=0x%04x; IE=0x%04x; CON=0x%04x; SYSTEST=0x%04x; SDA=%d%d [OI]; SCL=%d%d [OI] (%s:%d)\n", + msg, + omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG), + omap_i2c_read_reg(dev, OMAP_I2C_IE_REG), + omap_i2c_read_reg(dev, OMAP_I2C_CON_REG), + systest, + (systest & OMAP_I2C_SYSTEST_SDA_O_FUNC) ? 1 : 0, + (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC) ? 1 : 0, + (systest & OMAP_I2C_SYSTEST_SCL_O_FUNC) ? 1 : 0, + (systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) ? 1 : 0, + func, line); +} +#define OMAP_I2C_DUMP_STATE(dev, msg) omap_i2c_dump_state(__func__, __LINE__, (dev), (msg)) + static void __omap_i2c_init(struct omap_i2c_dev *dev) { @@ -469,6 +489,23 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) __omap_i2c_init(dev); + msleep(1); + OMAP_I2C_DUMP_STATE(dev, "init0"); + + dev->bb_valid = 0; + omap_i2c_wait_for_bb_valid(dev); + OMAP_I2C_DUMP_STATE(dev, "init1"); + dev_info(dev->dev, "init1: bb_valid=%d\n", dev->bb_valid); + + omap_i2c_reset(dev); + __omap_i2c_init(dev); + dev->bb_valid = 0; + omap_i2c_wait_for_bb_valid(dev); + OMAP_I2C_DUMP_STATE(dev, "init2"); + dev_info(dev->dev, "init2: bb_valid=%d\n", dev->bb_valid); + + dev->bb_valid = 1; + return 0; } @@ -1367,8 +1404,8 @@ omap_i2c_probe(struct platform_device *pdev) goto err_unuse_clocks; } - dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr, - major, minor, dev->speed); + dev_info(dev->dev, "bus %d rev%d.%d at %d kHz (rev %08x)\n", adap->nr, + major, minor, dev->speed, dev->rev); pm_runtime_mark_last_busy(dev->dev); pm_runtime_put_autosuspend(dev->dev); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
