[RFC PATCH alt 4/4] pinctrl: at91: rework debounce configuration
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Sat Sep 14 12:37:29 EDT 2013
On 09:53 Fri 13 Sep , Boris BREZILLON wrote:
> AT91 SoCs do not support per pin debounce time configuration.
> Instead you have to configure a debounce time which will be used for all
> pins of a given bank (PIOA, PIOB, ...).
>
> Signed-off-by: Boris BREZILLON <b.brezillon at overkiz.com>
> ---
> .../bindings/pinctrl/atmel,at91-pinctrl.txt | 9 ++-
> drivers/pinctrl/pinctrl-at91.c | 79 ++++++++++++++++----
> include/dt-bindings/pinctrl/at91.h | 1 -
> 3 files changed, 73 insertions(+), 16 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
> index cf7c7bc..8a4cdeb 100644
> --- a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
> +++ b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
> @@ -78,6 +78,14 @@ PA31 TXD4
>
> => 0xffc00c3b
>
> +Optional properties for iomux controller:
> +- atmel,default-debounce-div: array of debounce divisors (one divisor per bank)
> + which describes the debounce timing in use for all pins of a given bank
> + configured with the DEBOUNCE option (see the following description).
> + Debounce timing is obtained with this formula:
> + Tdebounce = 2 * (debouncediv + 1) / Fslowclk
> + with Fslowclk = 32KHz
I known that I put the div in the original binding
but maybe we should just put the debounce timing in the DT and calculate the
div in C
> +
> Required properties for pin configuration node:
> - atmel,pins: 4 integers array, represents a group of pins mux and config
> setting. The format is atmel,pins = <PIN_BANK PIN_BANK_NUM PERIPH CONFIG>.
> @@ -91,7 +99,6 @@ DEGLITCH (1 << 2): indicate this pin need deglitch.
> PULL_DOWN (1 << 3): indicate this pin need a pull down.
> DIS_SCHMIT (1 << 4): indicate this pin need to disable schmit trigger.
> DEBOUNCE (1 << 16): indicate this pin need debounce.
> -DEBOUNCE_VAL (0x3fff << 17): debounce val.
>
> NOTE:
> Some requirements for using atmel,at91rm9200-pinctrl binding:
> diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
> index ac9dbea..2903758 100644
> --- a/drivers/pinctrl/pinctrl-at91.c
> +++ b/drivers/pinctrl/pinctrl-at91.c
> @@ -62,8 +62,6 @@ static int gpio_banks;
> #define PULL_DOWN (1 << 3)
> #define DIS_SCHMIT (1 << 4)
> #define DEBOUNCE (1 << 16)
> -#define DEBOUNCE_VAL_SHIFT 17
> -#define DEBOUNCE_VAL (0x3fff << DEBOUNCE_VAL_SHIFT)
>
> /**
> * struct at91_pmx_func - describes AT91 pinmux functions
> @@ -145,8 +143,10 @@ struct at91_pinctrl_mux_ops {
> void (*mux_D_periph)(void __iomem *pio, unsigned mask);
> bool (*get_deglitch)(void __iomem *pio, unsigned pin);
> void (*set_deglitch)(void __iomem *pio, unsigned mask, bool is_on);
> - bool (*get_debounce)(void __iomem *pio, unsigned pin, u32 *div);
> - void (*set_debounce)(void __iomem *pio, unsigned mask, bool is_on, u32 div);
> + bool (*get_debounce)(void __iomem *pio, unsigned pin);
> + void (*set_debounce)(void __iomem *pio, unsigned mask, bool is_on);
> + u32 (*get_debounce_div)(void __iomem *pio);
> + void (*set_debounce_div)(void __iomem *pio, u32 div);
why do you split it?
if it's just get if on or not put NULL to div but do not add more function
pointer
> bool (*get_pulldown)(void __iomem *pio, unsigned pin);
> void (*set_pulldown)(void __iomem *pio, unsigned mask, bool is_on);
> bool (*get_schmitt_trig)(void __iomem *pio, unsigned pin);
> @@ -432,25 +432,32 @@ static void at91_mux_pio3_set_deglitch(void __iomem *pio, unsigned mask, bool is
> at91_mux_set_deglitch(pio, mask, is_on);
> }
>
> -static bool at91_mux_pio3_get_debounce(void __iomem *pio, unsigned pin, u32 *div)
> +static bool at91_mux_pio3_get_debounce(void __iomem *pio, unsigned pin)
> {
> - *div = __raw_readl(pio + PIO_SCDR);
> -
> return ((__raw_readl(pio + PIO_IFSR) >> pin) & 0x1) &&
> ((__raw_readl(pio + PIO_IFSCSR) >> pin) & 0x1);
> }
>
> static void at91_mux_pio3_set_debounce(void __iomem *pio, unsigned mask,
> - bool is_on, u32 div)
> + bool is_on)
> {
> if (is_on) {
> __raw_writel(mask, pio + PIO_IFSCER);
> - __raw_writel(div & PIO_SCDR_DIV, pio + PIO_SCDR);
> __raw_writel(mask, pio + PIO_IFER);
> } else
> __raw_writel(mask, pio + PIO_IFSCDR);
> }
>
> +static u32 at91_mux_pio3_get_debounce_div(void __iomem *pio)
> +{
> + return __raw_readl(pio + PIO_SCDR) & PIO_SCDR_DIV;
> +}
> +
> +static void at91_mux_pio3_set_debounce_div(void __iomem *pio, u32 div)
> +{
> + __raw_writel(div & PIO_SCDR_DIV, pio + PIO_SCDR);
> +}
> +
> static bool at91_mux_pio3_get_pulldown(void __iomem *pio, unsigned pin)
> {
> return !((__raw_readl(pio + PIO_PPDSR) >> pin) & 0x1);
> @@ -490,6 +497,8 @@ static struct at91_pinctrl_mux_ops at91sam9x5_ops = {
> .set_deglitch = at91_mux_pio3_set_deglitch,
> .get_debounce = at91_mux_pio3_get_debounce,
> .set_debounce = at91_mux_pio3_set_debounce,
> + .get_debounce_div = at91_mux_pio3_get_debounce_div,
> + .set_debounce_div = at91_mux_pio3_set_debounce_div,
> .get_pulldown = at91_mux_pio3_get_pulldown,
> .set_pulldown = at91_mux_pio3_set_pulldown,
> .get_schmitt_trig = at91_mux_pio3_get_schmitt_trig,
> @@ -719,7 +728,6 @@ static int at91_pinconf_get(struct pinctrl_dev *pctldev,
> struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
> void __iomem *pio;
> unsigned pin;
> - int div;
>
> dev_dbg(info->dev, "%s:%d, pin_id=%d, config=0x%lx", __func__, __LINE__, pin_id, *config);
> pio = pin_to_controller(info, pin_to_bank(pin_id));
> @@ -734,8 +742,8 @@ static int at91_pinconf_get(struct pinctrl_dev *pctldev,
>
> if (info->ops->get_deglitch && info->ops->get_deglitch(pio, pin))
> *config |= DEGLITCH;
> - if (info->ops->get_debounce && info->ops->get_debounce(pio, pin, &div))
> - *config |= DEBOUNCE | (div << DEBOUNCE_VAL_SHIFT);
> + if (info->ops->get_debounce && info->ops->get_debounce(pio, pin))
> + *config |= DEBOUNCE;
> if (info->ops->get_pulldown && info->ops->get_pulldown(pio, pin))
> *config |= PULL_DOWN;
> if (info->ops->get_schmitt_trig && info->ops->get_schmitt_trig(pio, pin))
> @@ -765,8 +773,7 @@ static int at91_pinconf_set(struct pinctrl_dev *pctldev,
> if (!info->ops->set_debounce)
> return -ENOTSUPP;
>
> - info->ops->set_debounce(pio, mask, config & DEBOUNCE,
> - (config & DEBOUNCE_VAL) >> DEBOUNCE_VAL_SHIFT);
> + info->ops->set_debounce(pio, mask, config & DEBOUNCE);
> } else if (info->ops->set_deglitch)
> info->ops->set_deglitch(pio, mask, config & DEGLITCH);
>
> @@ -822,6 +829,39 @@ static void at91_pinctrl_child_count(struct at91_pinctrl *info,
> }
> }
>
> +static int at91_pinctrl_default_debounce_div(struct at91_pinctrl *info,
> + struct device_node *np)
> +{
> + int size;
> + int i;
> + int ret;
> +
> + if (!info->ops->set_debounce_div ||
> + !of_get_property(np, "atmel,default-debounce-div", &size))
> + return 0;
> +
> + size /= sizeof(u32);
> + if (size != info->nbanks) {
> + dev_err(info->dev,
> + "atmel,default-debounce-div property should contain %d elements\n",
> + info->nbanks);
> + return -EINVAL;
> + }
> +
> + for (i = 0; i < info->nbanks; i++) {
> + u32 val;
> + ret = of_property_read_u32_index(np,
> + "atmel,default-debounce-div",
> + i, &val);
> + if (ret)
> + return ret;
> +
> + info->ops->set_debounce_div(gpio_chips[i]->regbase, val);
> + }
> +
> + return 0;
> +}
> +
> static int at91_pinctrl_mux_mask(struct at91_pinctrl *info,
> struct device_node *np)
> {
> @@ -972,6 +1012,10 @@ static int at91_pinctrl_probe_dt(struct platform_device *pdev,
> if (ret)
> return ret;
>
> + ret = at91_pinctrl_default_debounce_div(info, np);
> + if (ret)
> + return ret;
> +
> dev_dbg(&pdev->dev, "nmux = %d\n", info->nmux);
>
> dev_dbg(&pdev->dev, "mux-mask\n");
> @@ -982,6 +1026,13 @@ static int at91_pinctrl_probe_dt(struct platform_device *pdev,
> }
> }
>
> + if (info->ops->get_debounce_div) {
> + dev_dbg(&pdev->dev, "default-debounce-div\n");
> + for (i = 0; i < info->nbanks; i++)
> + dev_dbg(&pdev->dev, "bank %d\t%d\n", i,
> + info->ops->get_debounce_div(gpio_chips[i]->regbase));
> + }
> +
> dev_dbg(&pdev->dev, "nfunctions = %d\n", info->nfunctions);
> dev_dbg(&pdev->dev, "ngroups = %d\n", info->ngroups);
> info->functions = devm_kzalloc(&pdev->dev, info->nfunctions * sizeof(struct at91_pmx_func),
> diff --git a/include/dt-bindings/pinctrl/at91.h b/include/dt-bindings/pinctrl/at91.h
> index 0fee6ff..b478954 100644
> --- a/include/dt-bindings/pinctrl/at91.h
> +++ b/include/dt-bindings/pinctrl/at91.h
> @@ -16,7 +16,6 @@
> #define AT91_PINCTRL_PULL_DOWN (1 << 3)
> #define AT91_PINCTRL_DIS_SCHMIT (1 << 4)
> #define AT91_PINCTRL_DEBOUNCE (1 << 16)
> -#define AT91_PINCTRL_DEBOUNCE_VAL(x) (x << 17)
>
> #define AT91_PINCTRL_PULL_UP_DEGLITCH (AT91_PINCTRL_PULL_UP | AT91_PINCTRL_DEGLITCH)
>
> --
> 1.7.9.5
>
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