On 14-05-20, 10:00, Bjorn Andersson wrote:
> On Thu 14 May 07:15 PDT 2020, Vinod Koul wrote:
>
> > On 12-05-20, 17:54, Bjorn Andersson wrote:
> > > In all modern Qualcomm platforms the mutex region of the TCSR is forked
> > > off into its own block, all with a offset of 0 and stride of 4096. So
> > > add support for directly memory mapping this register space, to avoid
> > > the need to represent this block using a syscon.
> > >
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > > ---
> > > drivers/hwspinlock/qcom_hwspinlock.c | 72 +++++++++++++++++++++-------
> > > 1 file changed, 56 insertions(+), 16 deletions(-)
> > >
> > > diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c
> > > index f0da544b14d2..d8d4d729816c 100644
> > > --- a/drivers/hwspinlock/qcom_hwspinlock.c
> > > +++ b/drivers/hwspinlock/qcom_hwspinlock.c
> > > @@ -70,41 +70,81 @@ static const struct of_device_id qcom_hwspinlock_of_match[] = {
> > > };
> > > MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
> > >
> > > -static int qcom_hwspinlock_probe(struct platform_device *pdev)
> > > +static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
> > > + u32 *base, u32 *stride)
> > > {
> > > - struct hwspinlock_device *bank;
> > > struct device_node *syscon;
> > > - struct reg_field field;
> > > struct regmap *regmap;
> > > - size_t array_size;
> > > - u32 stride;
> > > - u32 base;
> > > int ret;
> > > - int i;
> > >
> > > syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
> > > - if (!syscon) {
> > > - dev_err(&pdev->dev, "no syscon property\n");
> >
> > any reason to drop the log?
> >
>
> Given that we first check for the syscon and then fall back to trying to
> use the reg, keeping this line would cause this log line to always show
> up on targets putting this under /soc.
>
> So I think it's better to drop the line and then require the presence of
> either syscon or reg using the DT schema.
ok
> > > - return -ENODEV;
> > > - }
> > > + if (!syscon)
> > > + return ERR_PTR(-ENODEV);
> > >
> > > regmap = syscon_node_to_regmap(syscon);
> > > of_node_put(syscon);
> > > if (IS_ERR(regmap))
> > > - return PTR_ERR(regmap);
> > > + return regmap;
> > >
> > > - ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base);
> > > + ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
> > > if (ret < 0) {
> > > dev_err(&pdev->dev, "no offset in syscon\n");
> > > - return -EINVAL;
> > > + return ERR_PTR(-EINVAL);
> > > }
> > >
> > > - ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride);
> > > + ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
> > > if (ret < 0) {
> > > dev_err(&pdev->dev, "no stride syscon\n");
> > > - return -EINVAL;
> > > + return ERR_PTR(-EINVAL);
> > > }
> > >
> > > + return regmap;
> > > +}
> > > +
> > > +static const struct regmap_config tcsr_mutex_config = {
> > > + .reg_bits = 32,
> > > + .reg_stride = 4,
> > > + .val_bits = 32,
> > > + .max_register = 0x40000,
> > > + .fast_io = true,
> > > +};
> > > +
> > > +static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
> > > + u32 *offset, u32 *stride)
> > > +{
> > > + struct device *dev = &pdev->dev;
> > > + struct resource *res;
> > > + void __iomem *base;
> > > +
> > > + /* All modern platform has offset 0 and stride of 4k */
> > > + *offset = 0;
> > > + *stride = 0x1000;
> >
> > Wouldn't it make sense to read this from DT rather than code in kernel?
> >
>
> I did consider this as well as platform specific compatibles, but
> realized that pretty much all 64-bit targets have these values. So given
> that we still can represent this using the syscon approach I don't think
> we need to add yet another mechanism to specify these.
Sounds good.
Reviewed-by: Vinod Koul <vkoul@xxxxxxxxxx>
--
~Vinod
