Hi!
> According to the TRM, we need to enable i2c access to powerbus before
> writing to it. Also, a new write to powerbus should not be attempted if
> there is a pending transfer. The current code does not implement that
> functionality and while there are no known problems caused by that, it is
> better to follow what TRM says.
>
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
> ---
> drivers/regulator/twl-regulator.c | 78 +++++++++++++++++++++++++++++++++++----
> 1 file changed, 70 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c
> index 955a6fb..aad748b0 100644
> --- a/drivers/regulator/twl-regulator.c
> +++ b/drivers/regulator/twl-regulator.c
> @@ -21,7 +21,7 @@
> #include <linux/regulator/machine.h>
> #include <linux/regulator/of_regulator.h>
> #include <linux/i2c/twl.h>
> -
> +#include <linux/delay.h>
>
> /*
> * The TWL4030/TW5030/TPS659x0/TWL6030 family chips include power management, a
> @@ -188,6 +188,74 @@ static int twl6030reg_is_enabled(struct regulator_dev *rdev)
> return grp && (val == TWL6030_CFG_STATE_ON);
> }
>
> +#define PB_I2C_BUSY BIT(0)
> +#define PB_I2C_BWEN BIT(1)
> +
> +/* Wait until buffer empty/ready to send a word on power bus. */
> +static int twl4030_wait_pb_ready(void)
> +{
> +
> + int ret;
> + int timeout = 10;
> + u8 val;
> +
Can we do this plain
while (timeout--) {
}...
? Also... if the bit is not immediately available, it will wait for
1msec. Would it make sense to have timeout = 1000 but wait only 10usec
each time or something?
Thanks,
Pavel
> + do {
> + ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
> + TWL4030_PM_MASTER_PB_CFG);
> + if (ret < 0)
> + return ret;
> +
> + if (!(val & PB_I2C_BUSY))
> + return 0;
> +
> + mdelay(1);
> + timeout--;
> + } while (timeout);
> +
> + return -ETIMEDOUT;
> +}
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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