[v4,7/7] thermal: mediatek: use spinlock to protect PTPCORESEL
Michael Kao
michael.kao at mediatek.com
Mon Jul 6 22:57:01 EDT 2020
On Fri, 2020-06-05 at 11:50 +0800, Michael Kao wrote:
> On Fri, 2020-05-22 at 17:36 +0200, Daniel Lezcano wrote:
> > On 23/03/2020 13:15, Michael Kao wrote:
> > > From: "michael.kao" <michael.kao at mediatek.com>
> > >
> > > The driver of thermal and svs will use the
> > > same register for the project which should select
> > > bank before reading sensor value.
> >
> > Here there is a design problem AFAICT. The sensor should not be using
> > external locks.
> >
> The PTPCORESEL is a common register used by svs and thermal.
> The thermal need to ensure PTPCORESEL register will not be changed by
> svs when thermal switch bank to read raw data of temperature.
> So we use svs_lock to make sure there is no conflict between the two
> drivers.
> >
> > > Signed-off-by: Michael Kao <michael.kao at mediatek.com>
> > > ---
> > > drivers/thermal/mtk_thermal.c | 9 ++++-----
> > > 1 file changed, 4 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
> > > index 9eaca432920e..594ad4f0f8cd 100644
> > > --- a/drivers/thermal/mtk_thermal.c
> > > +++ b/drivers/thermal/mtk_thermal.c
> > > @@ -22,6 +22,7 @@
> > > #include <linux/thermal.h>
> > > #include <linux/reset.h>
> > > #include <linux/types.h>
> > > +#include <linux/power/mtk_svs.h>
> > >
> > > /* AUXADC Registers */
> > > #define AUXADC_CON1_SET_V 0x008
> > > @@ -262,7 +263,7 @@ struct mtk_thermal {
> > > struct clk *clk_peri_therm;
> > > struct clk *clk_auxadc;
> > > /* lock: for getting and putting banks */
> > > - struct mutex lock;
> > > + unsigned long flags;
> > >
> > > /* Calibration values */
> > > s32 adc_ge;
> > > @@ -561,7 +562,7 @@ static void mtk_thermal_get_bank(struct mtk_thermal_bank *bank)
> > > u32 val;
> > >
> > > if (mt->conf->need_switch_bank) {
> > > - mutex_lock(&mt->lock);
> > > + mt->flags = claim_mtk_svs_lock();
> > >
> > > val = readl(mt->thermal_base + PTPCORESEL);
> > > val &= ~0xf;
> > > @@ -581,7 +582,7 @@ static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
> > > struct mtk_thermal *mt = bank->mt;
> > >
> > > if (mt->conf->need_switch_bank)
> > > - mutex_unlock(&mt->lock);
> > > + release_mtk_svs_lock(mt->flags);
> > > }
> > >
> > > /**
> > > @@ -938,8 +939,6 @@ static int mtk_thermal_probe(struct platform_device *pdev)
> > > if (ret)
> > > return ret;
> > >
> > > - mutex_init(&mt->lock);
> > > -
> > > mt->dev = &pdev->dev;
> > >
> > > auxadc = of_parse_phandle(np, "mediatek,auxadc", 0);
> > >
> >
> >
> Hi Daniel,
Gently ping.
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