Hi Sam,
Thanks for your review.
On Sat, 2 Dec 2023 at 00:22, Sam Protsenko <semen.protsenko@xxxxxxxxxx> wrote:
>
> On Fri, Dec 1, 2023 at 10:11 AM Peter Griffin <peter.griffin@xxxxxxxxxx> wrote:
> >
> > Newer Exynos SoCs have a filter selection register on alive bank pins.
> > This allows the selection of a digital or delay filter for each pin. If
> > the filter selection register is not available then the default filter
> > (digital) is applied.
> >
> > On suspend we apply the analog filter to all pins in the bank (as the
> > digital filter relies on a clock). On resume the digital filter is
> > reapplied to all pins in the bank. The digital filter is working via
> > clock and has an adjustable filter delay register bitfield, whereas
> > the analog filter uses a fixed delay.
> >
> > The filter determines to what extent signal fluctuations received through
> > the pad are considered glitches.
> >
> > The code path can be exercised using
> > echo mem > /sys/power/state
> > And then wake the device using a eint gpio
>
> Period.
Will fix
>
> >
> > Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> > ---
> > drivers/pinctrl/samsung/pinctrl-exynos.c | 89 ++++++++++++++++++++++-
> > drivers/pinctrl/samsung/pinctrl-exynos.h | 7 ++
> > drivers/pinctrl/samsung/pinctrl-samsung.c | 2 +
> > drivers/pinctrl/samsung/pinctrl-samsung.h | 22 ++++++
> > 4 files changed, 119 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pinctrl/samsung/pinctrl-exynos.c b/drivers/pinctrl/samsung/pinctrl-exynos.c
> > index 6b58ec84e34b..56fc11a1fe2f 100644
> > --- a/drivers/pinctrl/samsung/pinctrl-exynos.c
> > +++ b/drivers/pinctrl/samsung/pinctrl-exynos.c
> > @@ -269,6 +269,71 @@ struct exynos_eint_gpio_save {
> > u32 eint_mask;
> > };
> >
> > +/*
> > + * Set the desired filter (digital or analog delay) to every pin in
> > + * the bank. Note the filter selection bitfield is only found on alive
> > + * banks. The filter determines to what extent signal fluctuations
> > + * received through the pad are considered glitches.
> > + */
> > +static void exynos_eint_flt_config(struct samsung_pinctrl_drv_data *d,
> > + struct samsung_pin_bank *bank, int filter)
> > +{
> > + unsigned int flt_reg, flt_con = 0;
> > + unsigned int val, shift;
> > + int i;
> > + int loop_cnt;
> > +
> > + /*
> > + * The FLTCON register has the following layout
> > + *
> > + * BitfieldName[PinNum][Bit:Bit]
> > + * FLT_EN[3][31] FLT_SEL[3][30] FLT_WIDTH[3][29:24]
> > + * FLT_EN[2][23] FLT_SEL[2][22] FLT_WIDTH[2][21:16]
> > + * FLT_EN[1][15] FLT_SEL[1][14] FLT_WIDTH[1][13:8]
> > + * FLT_EN[0][7] FLT_SEL[0][6] FLT_WIDTH[0][5:0]
> > + *
> > + * FLT_EN 0x0 = Disable, 0x1=Enable
> > + * FLT_SEL 0x0 = Delay filter, 0x1 Digital filter
> > + * FLT_WIDTH Filtering width. Valid when FLT_SEL is 0x1
> > + */
> > +
> > + flt_con |= EXYNOS9_FLTCON_EN;
> > +
> > + if (filter)
> > + flt_con |= EXYNOS9_FLTCON_DIGITAL;
> > +
> > + flt_reg = EXYNOS_GPIO_EFLTCON_OFFSET + bank->fltcon_offset;
> > +
> > + /*
> > + * If nr_pins > 4, we should set FLTCON0 register fully.
> > + * (pin0 ~ 3). So loop 4 times in case of FLTCON0.
> > + */
> > + if (bank->nr_pins > EXYNOS9_FLTCON_NR_PIN)
> > + loop_cnt = EXYNOS9_FLTCON_NR_PIN;
> > + else
> > + loop_cnt = bank->nr_pins;
> > +
> > + val = readl(d->virt_base + flt_reg);
> > + for (i = 0; i < loop_cnt; i++) {
> > + shift = i * EXYNOS9_FLTCON_LEN;
> > + val &= ~(EXYNOS9_FLTCON_MASK << shift);
> > + val |= (flt_con << shift);
> > + }
> > + writel(val, d->virt_base + flt_reg);
> > +
> > + /* Loop for FLTCON1 pin 4 ~ 7 */
> > + if (bank->nr_pins > EXYNOS9_FLTCON_NR_PIN) {
> > + loop_cnt = (bank->nr_pins - EXYNOS9_FLTCON_NR_PIN);
> > + val = readl(d->virt_base + flt_reg + 0x4);
> > + for (i = 0; i < loop_cnt; i++) {
> > + shift = i * EXYNOS9_FLTCON_LEN;
> > + val &= ~(EXYNOS9_FLTCON_MASK << shift);
> > + val |= (flt_con << shift);
> > + }
> > + writel(val, d->virt_base + flt_reg + 0x4);
> > + }
> > +}
> > +
>
> This whole function needs a refactoring. Do you think below code looks better?
Yes it does!
>
> 8<----------------------------------------------------------------->8
> static void exynos_eint_update_flt_reg(void __iomem *reg, int cnt, int con)
> {
> unsigned int val, shift;
> int i;
>
> val = readl(reg);
> for (i = 0; i < cnt; i++) {
> shift = i * EXYNOS9_FLTCON_LEN;
> val &= ~(EXYNOS9_FLTCON_MASK << shift);
> val |= con << shift;
> }
> writel(val, reg);
> }
>
> /*
> * Set the desired filter (digital or analog delay) to every pin in the bank.
> * Note the filter selection bitfield is only found on alive banks. The filter
> * determines to what extent signal fluctuations received through the pad are
> * considered glitches.
> *
> * The FLTCON register has the following layout:
> *
> * BitfieldName[PinNum][Bit:Bit]
> * FLT_EN[3][31] FLT_SEL[3][30] FLT_WIDTH[3][29:24]
> * FLT_EN[2][23] FLT_SEL[2][22] FLT_WIDTH[2][21:16]
> * FLT_EN[1][15] FLT_SEL[1][14] FLT_WIDTH[1][13:8]
> * FLT_EN[0][7] FLT_SEL[0][6] FLT_WIDTH[0][5:0]
> *
> * FLT_EN 0x0 = Disable, 0x1 = Enable
> * FLT_SEL 0x0 = Delay filter, 0x1 = Digital filter
> * FLT_WIDTH Filtering width. Valid when FLT_SEL is 0x1
> */
> static void exynos_eint_flt_config(struct samsung_pinctrl_drv_data *d,
> struct samsung_pin_bank *bank, int filter)
> {
> unsigned int off = EXYNOS_GPIO_EFLTCON_OFFSET + bank->fltcon_offset;
> unsigned int con = EXYNOS9_FLTCON_EN | filter;
> void __iomem *reg = d->virt_base + off;
> u8 n = bank->nr_pins;
>
> if (bank->fltcon_type == FLT_DEFAULT)
> return;
>
> /*
> * If nr_pins > 4, we should set FLTCON0 register fully (pin0~3).
> * So loop 4 times in case of FLTCON0. Loop for FLTCON1 pin4~7.
> */
> if (n <= 4) {
> exynos_eint_update_flt_reg(reg, n, con);
> } else {
> exynos_eint_update_flt_reg(reg, 4, con);
> exynos_eint_update_flt_reg(reg + 0x4, n - 4, con);
> }
> }
> 8<----------------------------------------------------------------->8
>
> (the code is only to illustrate the idea, I never tested it).
I can refactor it along those lines.
>
> > /*
> > * exynos_eint_gpio_init() - setup handling of external gpio interrupts.
> > * @d: driver data of samsung pinctrl driver.
> > @@ -321,6 +386,10 @@ __init int exynos_eint_gpio_init(struct samsung_pinctrl_drv_data *d)
> > goto err_domains;
> > }
> >
> > + /* Set Delay Analog Filter */
>
> The code below looks quite self-explanatory to. Maybe remove all
> comments like this? If you don't think exynos_eint_flt_config() is
> clear, maybe rename it to exynos_eint_set_filter().
Ok, I will update the function name to exynos_eint_set_filter() and
remove the comments.
>
> > + if (bank->fltcon_type != FLT_DEFAULT)
> > + exynos_eint_flt_config(d, bank,
> > + EXYNOS9_FLTCON_DELAY);
>
> It fits the previous line just fine, no need to break the line.
>
> Also, if you use the refactored version of exynos_eint_flt_config() I
> mentioned above, you can drop all 'if' conditions like this.
Will fix
>
> > }
> >
> > return 0;
> > @@ -555,6 +624,11 @@ __init int exynos_eint_wkup_init(struct samsung_pinctrl_drv_data *d)
> > if (bank->eint_type != EINT_TYPE_WKUP)
> > continue;
> >
> > + /* Set Digital Filter */
> > + if (bank->fltcon_type != FLT_DEFAULT)
> > + exynos_eint_flt_config(d, bank,
> > + EXYNOS9_FLTCON_DIGITAL);
>
> Ditto: no need to break the line, remove the comment. If you use the
> refactored function, you can drop 'if'.
will fix
>
> > +
> > bank->irq_chip = devm_kmemdup(dev, irq_chip, sizeof(*irq_chip),
> > GFP_KERNEL);
> > if (!bank->irq_chip) {
> > @@ -658,6 +732,7 @@ static void exynos_pinctrl_suspend_bank(
> > void exynos_pinctrl_suspend(struct samsung_pinctrl_drv_data *drvdata)
> > {
> > struct samsung_pin_bank *bank = drvdata->pin_banks;
> > + struct samsung_pinctrl_drv_data *d = bank->drvdata;
> > struct exynos_irq_chip *irq_chip = NULL;
> > int i;
> >
> > @@ -665,6 +740,10 @@ void exynos_pinctrl_suspend(struct samsung_pinctrl_drv_data *drvdata)
> > if (bank->eint_type == EINT_TYPE_GPIO)
> > exynos_pinctrl_suspend_bank(drvdata, bank);
> > else if (bank->eint_type == EINT_TYPE_WKUP) {
> > + /* Setting Delay (Analog) Filter */
> > + if (bank->fltcon_type != FLT_DEFAULT)
> > + exynos_eint_flt_config(d, bank,
> > + EXYNOS9_FLTCON_DELAY);
>
> Ditto: no need to break the line, remove the comment. If you use the
> refactored function, you can drop 'if'.
Will fix
>
> > if (!irq_chip) {
> > irq_chip = bank->irq_chip;
> > irq_chip->set_eint_wakeup_mask(drvdata,
> > @@ -707,11 +786,19 @@ static void exynos_pinctrl_resume_bank(
> > void exynos_pinctrl_resume(struct samsung_pinctrl_drv_data *drvdata)
> > {
> > struct samsung_pin_bank *bank = drvdata->pin_banks;
> > + struct samsung_pinctrl_drv_data *d = bank->drvdata;
> > int i;
> >
> > for (i = 0; i < drvdata->nr_banks; ++i, ++bank)
> > - if (bank->eint_type == EINT_TYPE_GPIO)
> > + if (bank->eint_type == EINT_TYPE_GPIO) {
> > exynos_pinctrl_resume_bank(drvdata, bank);
> > + } else if (bank->eint_type == EINT_TYPE_WKUP ||
> > + bank->eint_type == EINT_TYPE_WKUP_MUX) {
> > + /* Set Digital Filter */
> > + if (bank->fltcon_type != FLT_DEFAULT)
> > + exynos_eint_flt_config(d, bank,
> > + EXYNOS9_FLTCON_DIGITAL);
>
> Ditto: remove the comment, and if you use the refactored function, you
> can drop 'if'; also there will be no need to break the line.
Will fix
>
> > + }
> > }
> >
> > static void exynos_retention_enable(struct samsung_pinctrl_drv_data *drvdata)
> > diff --git a/drivers/pinctrl/samsung/pinctrl-exynos.h b/drivers/pinctrl/samsung/pinctrl-exynos.h
> > index 3ac52c2cf998..e2799ff1b5e9 100644
> > --- a/drivers/pinctrl/samsung/pinctrl-exynos.h
> > +++ b/drivers/pinctrl/samsung/pinctrl-exynos.h
> > @@ -50,6 +50,13 @@
> >
> > #define EXYNOS_EINT_MAX_PER_BANK 8
> > #define EXYNOS_EINT_NR_WKUP_EINT
>
> Maybe add an empty line here?
Will fix
>
> > +/* EINT filter configuration */
> > +#define EXYNOS9_FLTCON_EN BIT(7)
> > +#define EXYNOS9_FLTCON_DIGITAL BIT(6)
> > +#define EXYNOS9_FLTCON_DELAY (0 << 6)
> > +#define EXYNOS9_FLTCON_MASK 0xff
> > +#define EXYNOS9_FLTCON_LEN 8
> > +#define EXYNOS9_FLTCON_NR_PIN 4
>
> I'd say drop this one and just hard-code it where needed?
Ok, will drop.
>
> >
> > #define EXYNOS_PIN_BANK_EINTN(pins, reg, id) \
> > { \
> > diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.c b/drivers/pinctrl/samsung/pinctrl-samsung.c
> > index 79babbb39ced..50c360b4753a 100644
> > --- a/drivers/pinctrl/samsung/pinctrl-samsung.c
> > +++ b/drivers/pinctrl/samsung/pinctrl-samsung.c
> > @@ -1105,6 +1105,8 @@ samsung_pinctrl_get_soc_data(struct samsung_pinctrl_drv_data *d,
> > bank->eint_func = bdata->eint_func;
> > bank->eint_type = bdata->eint_type;
> > bank->eint_mask = bdata->eint_mask;
> > + bank->fltcon_type = bdata->fltcon_type;
> > + bank->fltcon_offset = bdata->fltcon_offset;
> > bank->eint_offset = bdata->eint_offset;
> > bank->name = bdata->name;
> >
> > diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.h b/drivers/pinctrl/samsung/pinctrl-samsung.h
> > index 9b3db50adef3..5fab3885a7d7 100644
> > --- a/drivers/pinctrl/samsung/pinctrl-samsung.h
> > +++ b/drivers/pinctrl/samsung/pinctrl-samsung.h
> > @@ -82,6 +82,20 @@ enum eint_type {
> > EINT_TYPE_WKUP_MUX,
> > };
> >
> > +/**
> > + * enum fltcon_type - filter selection
> > + * @FLT_DEFAULT: filter not selectable, default digital filter
> > + * @FLT_SELECT: filter selectable (digital or delay)
> > + *
> > + * Some banks on newer Exynos based SoCs have a selectable filter on alive
> > + * banks of 'analog/delay' or 'digital'. If the filter selection register is
> > + * not available then the default filter is used (digital).
> > + */
> > +enum fltcon_type {
> > + FLT_DEFAULT,
> > + FLT_SELECTABLE,
> > +};
>
> Is there any benefit of having this enum over replacing it with just a
> bool field (e.g. 'bool flt_selectable')?
I thought it made it clearer at the callee sites which filter was
being set, but I can update to a bool if that's what you prefer.
regards,
Peter.
>
> > +
> > /* maximum length of a pin in pin descriptor (example: "gpa0-0") */
> > #define PIN_NAME_LENGTH 10
> >
> > @@ -122,6 +136,8 @@ struct samsung_pin_bank_type {
> > * @eint_type: type of the external interrupt supported by the bank.
> > * @eint_mask: bit mask of pins which support EINT function.
> > * @eint_offset: SoC-specific EINT register or interrupt offset of bank.
> > + * @fltcon_type: whether the filter (delay/digital) is selectable
> > + * @fltcon_offset: SoC-specific EINT filter control register offset of bank.
> > * @name: name to be prefixed for each pin in this pin bank.
> > */
> > struct samsung_pin_bank_data {
> > @@ -133,6 +149,8 @@ struct samsung_pin_bank_data {
> > enum eint_type eint_type;
> > u32 eint_mask;
> > u32 eint_offset;
> > + enum fltcon_type fltcon_type;
> > + u32 fltcon_offset;
> > const char *name;
> > };
> >
> > @@ -147,6 +165,8 @@ struct samsung_pin_bank_data {
> > * @eint_type: type of the external interrupt supported by the bank.
> > * @eint_mask: bit mask of pins which support EINT function.
> > * @eint_offset: SoC-specific EINT register or interrupt offset of bank.
> > + * @fltcon_type: whether the filter (delay/digital) is selectable
> > + * @fltcon_offset: SoC-specific EINT filter control register offset of bank.
> > * @name: name to be prefixed for each pin in this pin bank.
> > * @id: id of the bank, propagated to the pin range.
> > * @pin_base: starting pin number of the bank.
> > @@ -170,6 +190,8 @@ struct samsung_pin_bank {
> > enum eint_type eint_type;
> > u32 eint_mask;
> > u32 eint_offset;
> > + enum fltcon_type fltcon_type;
> > + u32 fltcon_offset;
> > const char *name;
> > u32 id;
> >
> > --
> > 2.43.0.rc2.451.g8631bc7472-goog
> >
