Re: [RFC PATCH alt 4/4] pinctrl: at91: rework debounce configuration
From: boris brezillon
Date: Sun Sep 15 2013 - 02:22:42 EST
Hello Jean-Christophe,
Le 14/09/2013 18:37, Jean-Christophe PLAGNIOL-VILLARD a écrit :
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@xxxxxxxxxxx>
---
.../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
Sure, I can do this: retrieve a debounce time (in usec ?) and compute the
according div value.
+
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
I not sure I got your point.
Are you suggesting we should store the default bank bebounce div values
in struct at91_pinctrl
(during probe process) and pass these values each time the set_debounce
function is called ?
IMHO if we split the logic (split debounce activation and debounce time
definition) we should split
these callbacks:
- one callback to enable debounce option on a given pin
- one callback to configure the debounce time for a given bank
If you keep the div parameter in the debounce enable/disable callback
you will reconfigure the div
register (PIO_SCDR_DIV) each time you enable the debounce option, which
is kind of useless
because the div value will never change.
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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/