Am Dienstag, 23. Juni 2020, 14:06:46 CEST schrieb John Keeping:
> Enable i2c transactions in irq disabled contexts like poweroff where the
> PMIC is connected via i2c.
>
> Signed-off-by: John Keeping <john@xxxxxxxxxxxx>
on a rk3288:
Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-rk3x.c | 39 +++++++++++++++++++++++++++++++----
> 1 file changed, 35 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
> index 15324bfbc6cb..8e3cc85d1921 100644
> --- a/drivers/i2c/busses/i2c-rk3x.c
> +++ b/drivers/i2c/busses/i2c-rk3x.c
> @@ -10,6 +10,7 @@
> #include <linux/module.h>
> #include <linux/i2c.h>
> #include <linux/interrupt.h>
> +#include <linux/iopoll.h>
> #include <linux/errno.h>
> #include <linux/err.h>
> #include <linux/platform_device.h>
> @@ -1040,8 +1041,21 @@ static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, int num)
> return ret;
> }
>
> -static int rk3x_i2c_xfer(struct i2c_adapter *adap,
> - struct i2c_msg *msgs, int num)
> +static int rk3x_i2c_wait_xfer_poll(struct rk3x_i2c *i2c)
> +{
> + ktime_t timeout = ktime_add_ms(ktime_get(), WAIT_TIMEOUT);
> +
> + while (READ_ONCE(i2c->busy) &&
> + ktime_compare(ktime_get(), timeout) < 0) {
> + udelay(5);
> + rk3x_i2c_irq(0, i2c);
> + }
> +
> + return !i2c->busy;
> +}
> +
> +static int rk3x_i2c_xfer_common(struct i2c_adapter *adap,
> + struct i2c_msg *msgs, int num, bool polling)
> {
> struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data;
> unsigned long timeout, flags;
> @@ -1075,8 +1089,12 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
>
> rk3x_i2c_start(i2c);
>
> - timeout = wait_event_timeout(i2c->wait, !i2c->busy,
> - msecs_to_jiffies(WAIT_TIMEOUT));
> + if (!polling) {
> + timeout = wait_event_timeout(i2c->wait, !i2c->busy,
> + msecs_to_jiffies(WAIT_TIMEOUT));
> + } else {
> + timeout = rk3x_i2c_wait_xfer_poll(i2c);
> + }
>
> spin_lock_irqsave(&i2c->lock, flags);
>
> @@ -1110,6 +1128,18 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
> return ret < 0 ? ret : num;
> }
>
> +static int rk3x_i2c_xfer(struct i2c_adapter *adap,
> + struct i2c_msg *msgs, int num)
> +{
> + return rk3x_i2c_xfer_common(adap, msgs, num, false);
> +}
> +
> +static int rk3x_i2c_xfer_polling(struct i2c_adapter *adap,
> + struct i2c_msg *msgs, int num)
> +{
> + return rk3x_i2c_xfer_common(adap, msgs, num, true);
> +}
> +
> static __maybe_unused int rk3x_i2c_resume(struct device *dev)
> {
> struct rk3x_i2c *i2c = dev_get_drvdata(dev);
> @@ -1126,6 +1156,7 @@ static u32 rk3x_i2c_func(struct i2c_adapter *adap)
>
> static const struct i2c_algorithm rk3x_i2c_algorithm = {
> .master_xfer = rk3x_i2c_xfer,
> + .master_xfer_atomic = rk3x_i2c_xfer_polling,
> .functionality = rk3x_i2c_func,
> };
>
>
