From 1bd231538c21d1cd691e71cbeeb4100fabc58068 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 12 Aug 2019 19:14:01 +0300 Subject: 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: Andy Shevchenko Reviewed-by: Linus Walleij Acked-by: Mika Westerberg --- drivers/pinctrl/intel/pinctrl-intel.c | 69 ++++++++++++++++++++++++++--------- 1 file changed, 52 insertions(+), 17 deletions(-) (limited to 'drivers/pinctrl') diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c index c949df07cbdf..104dfaa78cb8 100644 --- a/drivers/pinctrl/intel/pinctrl-intel.c +++ b/drivers/pinctrl/intel/pinctrl-intel.c @@ -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) - 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 +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) */ -- cgit v1.2.3