* [PATCH v2] pinctrl: intel: Allow to request locked pads
@ 2019-08-08 13:21 Andy Shevchenko
2019-08-09 8:40 ` Mika Westerberg
2019-08-09 12:58 ` Linus Walleij
0 siblings, 2 replies; 3+ messages in thread
From: Andy Shevchenko @ 2019-08-08 13:21 UTC (permalink / raw)
To: Mika Westerberg, linux-gpio, Linus Walleij; +Cc: Andy Shevchenko
Some firmwares would like to protect pads from being modified by OS
and at the same time provide them to OS as a resource. So, the driver
in such circumstances may request pad and may not change its state.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
in v2:
- amended comment in intel_pad_locked() respectively to the change (Mika)
- described enum values (Linus)
- lowered case for locking flavour in debugfs for better looking
drivers/pinctrl/intel/pinctrl-intel.c | 67 ++++++++++++++++++++-------
1 file changed, 50 insertions(+), 17 deletions(-)
diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
index c949df07cbdf..b84a5579beee 100644
--- a/drivers/pinctrl/intel/pinctrl-intel.c
+++ b/drivers/pinctrl/intel/pinctrl-intel.c
@@ -220,47 +220,69 @@ static bool intel_pad_acpi_mode(struct intel_pinctrl *pctrl, unsigned int pin)
return !(readl(hostown) & BIT(gpp_offset));
}
-static bool intel_pad_locked(struct intel_pinctrl *pctrl, unsigned int pin)
+/*
+ * PAD_UNLOCKED: pad is fully controlled by the configuration registers
+ * PAD_LOCKED: pad configuration registers, except TX state, are locked
+ * PAD_LOCKED_TX: pad configuration TX state is locked
+ * PAD_LOCKED_FULL: pad configuration registers are locked completely
+ *
+ * Locking is considered as read-only mode for corresponding registers and
+ * their respective fields. That said, TX state bit is locked separately from
+ * the main locking scheme.
+ */
+enum {
+ PAD_UNLOCKED = 0,
+ PAD_LOCKED = 1,
+ PAD_LOCKED_TX = 2,
+ PAD_LOCKED_FULL = PAD_LOCKED | PAD_LOCKED_TX,
+};
+
+static int intel_pad_locked(struct intel_pinctrl *pctrl, unsigned int pin)
{
struct intel_community *community;
const struct intel_padgroup *padgrp;
unsigned int offset, gpp_offset;
u32 value;
+ int ret = PAD_UNLOCKED;
community = intel_get_community(pctrl, pin);
if (!community)
- return true;
+ return PAD_LOCKED_FULL;
if (!community->padcfglock_offset)
- return false;
+ return PAD_UNLOCKED;
padgrp = intel_community_get_padgroup(community, pin);
if (!padgrp)
- return true;
+ return PAD_LOCKED_FULL;
gpp_offset = padgroup_offset(padgrp, pin);
/*
* If PADCFGLOCK and PADCFGLOCKTX bits are both clear for this pad,
* the pad is considered unlocked. Any other case means that it is
- * either fully or partially locked and we don't touch it.
+ * either fully or partially locked.
*/
- offset = community->padcfglock_offset + padgrp->reg_num * 8;
+ offset = community->padcfglock_offset + 0 + padgrp->reg_num * 8;
value = readl(community->regs + offset);
if (value & BIT(gpp_offset))
- return true;
+ ret |= PAD_LOCKED;
offset = community->padcfglock_offset + 4 + padgrp->reg_num * 8;
value = readl(community->regs + offset);
if (value & BIT(gpp_offset))
- return true;
+ ret |= PAD_LOCKED_TX;
- return false;
+ return ret;
+}
+
+static bool intel_pad_is_unlocked(struct intel_pinctrl *pctrl, unsigned int pin)
+{
+ return (intel_pad_locked(pctrl, pin) & PAD_LOCKED) == PAD_UNLOCKED;
}
static bool intel_pad_usable(struct intel_pinctrl *pctrl, unsigned int pin)
{
- return intel_pad_owned_by_host(pctrl, pin) &&
- !intel_pad_locked(pctrl, pin);
+ return intel_pad_owned_by_host(pctrl, pin) && intel_pad_is_unlocked(pctrl, pin);
}
static int intel_get_groups_count(struct pinctrl_dev *pctldev)
@@ -294,7 +316,8 @@ static void intel_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
void __iomem *padcfg;
u32 cfg0, cfg1, mode;
- bool locked, acpi;
+ int locked;
+ bool acpi;
if (!intel_pad_owned_by_host(pctrl, pin)) {
seq_puts(s, "not available");
@@ -322,11 +345,16 @@ static void intel_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
if (locked || acpi) {
seq_puts(s, " [");
- if (locked) {
+ if (locked)
seq_puts(s, "LOCKED");
- if (acpi)
- seq_puts(s, ", ");
- }
+ if ((locked & PAD_LOCKED_FULL) == PAD_LOCKED_TX)
+ seq_puts(s, " tx");
+ else if ((locked & PAD_LOCKED_FULL) == PAD_LOCKED_FULL)
+ seq_puts(s, " full");
+
+ if (locked && acpi)
+ seq_puts(s, ", ");
+
if (acpi)
seq_puts(s, "ACPI");
seq_puts(s, "]");
@@ -448,11 +476,16 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
raw_spin_lock_irqsave(&pctrl->lock, flags);
- if (!intel_pad_usable(pctrl, pin)) {
+ if (!intel_pad_owned_by_host(pctrl, pin)) {
raw_spin_unlock_irqrestore(&pctrl->lock, flags);
return -EBUSY;
}
+ if (!intel_pad_is_unlocked(pctrl, pin)) {
+ raw_spin_unlock_irqrestore(&pctrl->lock, flags);
+ return 0;
+ }
+
padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
intel_gpio_set_gpio_mode(padcfg0);
/* Disable TX buffer and enable RX (this will be input) */
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] pinctrl: intel: Allow to request locked pads
2019-08-08 13:21 [PATCH v2] pinctrl: intel: Allow to request locked pads Andy Shevchenko
@ 2019-08-09 8:40 ` Mika Westerberg
2019-08-09 12:58 ` Linus Walleij
1 sibling, 0 replies; 3+ messages in thread
From: Mika Westerberg @ 2019-08-09 8:40 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: linux-gpio, Linus Walleij
On Thu, Aug 08, 2019 at 04:21:28PM +0300, Andy Shevchenko wrote:
> Some firmwares would like to protect pads from being modified by OS
> and at the same time provide them to OS as a resource. So, the driver
> in such circumstances may request pad and may not change its state.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> in v2:
> - amended comment in intel_pad_locked() respectively to the change (Mika)
> - described enum values (Linus)
> - lowered case for locking flavour in debugfs for better looking
> drivers/pinctrl/intel/pinctrl-intel.c | 67 ++++++++++++++++++++-------
> 1 file changed, 50 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
> index c949df07cbdf..b84a5579beee 100644
> --- a/drivers/pinctrl/intel/pinctrl-intel.c
> +++ b/drivers/pinctrl/intel/pinctrl-intel.c
> @@ -220,47 +220,69 @@ static bool intel_pad_acpi_mode(struct intel_pinctrl *pctrl, unsigned int pin)
> return !(readl(hostown) & BIT(gpp_offset));
> }
>
> -static bool intel_pad_locked(struct intel_pinctrl *pctrl, unsigned int pin)
> +/*
This should be /**
> + * PAD_UNLOCKED: pad is fully controlled by the configuration registers
These should have @ prefix, I think.
Otherwise looks good.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] pinctrl: intel: Allow to request locked pads
2019-08-08 13:21 [PATCH v2] pinctrl: intel: Allow to request locked pads Andy Shevchenko
2019-08-09 8:40 ` Mika Westerberg
@ 2019-08-09 12:58 ` Linus Walleij
1 sibling, 0 replies; 3+ messages in thread
From: Linus Walleij @ 2019-08-09 12:58 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: Mika Westerberg, open list:GPIO SUBSYSTEM
On Thu, Aug 8, 2019 at 3:21 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> Some firmwares would like to protect pads from being modified by OS
> and at the same time provide them to OS as a resource. So, the driver
> in such circumstances may request pad and may not change its state.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> in v2:
> - amended comment in intel_pad_locked() respectively to the change (Mika)
> - described enum values (Linus)
> - lowered case for locking flavour in debugfs for better looking
> drivers/pinctrl/intel/pinctrl-intel.c | 67 ++++++++++++++++++++-------
> 1 file changed, 50 insertions(+), 17 deletions(-)
Mika pointed out some typos or so, apart from that:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-08-09 8:40 ` Mika Westerberg
2019-08-09 12:58 ` Linus Walleij
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