Commit 1bd23153 authored by Andy Shevchenko's avatar Andy Shevchenko
Browse files

pinctrl: intel: Allow to request locked pads 



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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent bf5ab1bd

drivers/pinctrl/intel/pinctrl-intel.c

+52 −17
Original line number Diff line number Diff line
@@ -220,47 +220,71 @@ 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)

/**

 * enum - Locking variants of the pad configuration

 *

 * @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 +318,8 @@ 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 +347,16 @@ 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)

		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 +478,16 @@ 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) */

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