On Fri, 4 Feb 2022 at 12:03, Robert Foss <robert.foss@xxxxxxxxxx> wrote:
>
> On Thu, 3 Feb 2022 at 17:47, Vladimir Zapolskiy
> <vladimir.zapolskiy@xxxxxxxxxx> wrote:
> >
> > The change adds handling of optional vbus regulators in the driver.
> >
> > Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
> > ---
> > drivers/i2c/busses/i2c-qcom-cci.c | 49 +++++++++++++++++++++++++++++++
> > 1 file changed, 49 insertions(+)
> >
> > diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
> > index 775945f7b4cd..2fc7f1f2616f 100644
> > --- a/drivers/i2c/busses/i2c-qcom-cci.c
> > +++ b/drivers/i2c/busses/i2c-qcom-cci.c
> > @@ -11,6 +11,7 @@
> > #include <linux/of.h>
> > #include <linux/platform_device.h>
> > #include <linux/pm_runtime.h>
> > +#include <linux/regulator/consumer.h>
> >
> > #define CCI_HW_VERSION 0x0
> > #define CCI_RESET_CMD 0x004
> > @@ -480,6 +481,20 @@ static void cci_disable_clocks(struct cci *cci)
> > static int __maybe_unused cci_suspend_runtime(struct device *dev)
> > {
> > struct cci *cci = dev_get_drvdata(dev);
> > + struct regulator *bus_regulator;
> > + unsigned int i;
> > +
> > + for (i = 0; i < cci->data->num_masters; i++) {
> > + if (!cci->master[i].cci)
> > + continue;
> > +
> > + bus_regulator = cci->master[i].adap.bus_regulator;
> > + if (!bus_regulator)
> > + continue;
> > +
> > + if (regulator_is_enabled(bus_regulator) > 0)
>
> Is this check needed? No matter the current status of the regulator,
> we'd like to disable it, and from my reading regulator_disable can be
> called for already disabled regulators.
+1, but why do we even assign this regulator to each adapter, a
simpler solution would be to have the regulator part of the cci
struct, and simply disable/enable it on runtime suspend/resume,
without extra loop/check. I2C core does nothing with
adap.bus_regulator anyway (5a7b95fb993e has been partially reverted).
>
> > + regulator_disable(bus_regulator);
> > + }
> >
> > cci_disable_clocks(cci);
> > return 0;
> > @@ -488,12 +503,30 @@ static int __maybe_unused cci_suspend_runtime(struct device *dev)
> > static int __maybe_unused cci_resume_runtime(struct device *dev)
> > {
> > struct cci *cci = dev_get_drvdata(dev);
> > + struct regulator *bus_regulator;
> > + unsigned int i;
> > int ret;
> >
> > ret = cci_enable_clocks(cci);
> > if (ret)
> > return ret;
> >
> > + for (i = 0; i < cci->data->num_masters; i++) {
> > + if (!cci->master[i].cci)
> > + continue;
> > +
> > + bus_regulator = cci->master[i].adap.bus_regulator;
> > + if (!bus_regulator)
> > + continue;
> > +
> > + if (!regulator_is_enabled(bus_regulator)) {
> > + ret = regulator_enable(bus_regulator);
> > + if (ret)
> > + dev_err(dev, "failed to enable regulator: %d\n",
> > + ret);
> > + }
> > + }
> > +
> > cci_init(cci);
> > return 0;
> > }
> > @@ -593,6 +626,7 @@ static int cci_probe(struct platform_device *pdev)
> > dev_dbg(dev, "CCI HW version = 0x%08x", val);
> >
> > for_each_available_child_of_node(dev->of_node, child) {
> > + struct regulator *bus_regulator;
> > struct cci_master *master;
> > u32 idx;
> >
> > @@ -637,6 +671,21 @@ static int cci_probe(struct platform_device *pdev)
> > master->cci = NULL;
> > goto error_i2c;
> > }
> > +
> > + /*
> > + * It might be possible to find an optional vbus supply, but
> > + * it requires to pass the registration of an I2C adapter
> > + * device and its association with a bus device tree node.
> > + */
> > + bus_regulator = devm_regulator_get_optional(&master->adap.dev,
> > + "vbus");
> > + if (IS_ERR(bus_regulator)) {
> > + ret = PTR_ERR(bus_regulator);
> > + if (ret == -EPROBE_DEFER)
> > + goto error_i2c;
> > + bus_regulator = NULL;
> > + }
> > + master->adap.bus_regulator = bus_regulator;
> > }
> >
> > ret = cci_reset(cci);
> > --
> > 2.33.0
> >
>
> With the above nit sorted, feel free to add my r-b.
>
> Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxx>
