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linux_dsm_epyc7002/drivers/pinctrl/mediatek/mtk-eint.c
Nicolas Boichat 9d957a959b pinctrl: mediatek: Update cur_mask in mask/mask ops 
During suspend/resume, mtk_eint_mask may be called while
wake_mask is active. For example, this happens if a wake-source
with an active interrupt handler wakes the system:
irq/pm.c:irq_pm_check_wakeup would disable the interrupt, so
that it can be handled later on in the resume flow.

However, this may happen before mtk_eint_do_resume is called:
in this case, wake_mask is loaded, and cur_mask is restored
from an older copy, re-enabling the interrupt, and causing
an interrupt storm (especially for level interrupts).

Step by step, for a line that has both wake and interrupt enabled:
 1. cur_mask[irq] = 1; wake_mask[irq] = 1; EINT_EN[irq] = 1 (interrupt
    enabled at hardware level)
 2. System suspends, resumes due to that line (at this stage EINT_EN
    == wake_mask)
 3. irq_pm_check_wakeup is called, and disables the interrupt =>
    EINT_EN[irq] = 0, but we still have cur_mask[irq] = 1
 4. mtk_eint_do_resume is called, and restores EINT_EN = cur_mask, so
    it reenables EINT_EN[irq] = 1 => interrupt storm as the driver
    is not yet ready to handle the interrupt.

This patch fixes the issue in step 3, by recording all mask/unmask
changes in cur_mask. This also avoids the need to read the current
mask in eint_do_suspend, and we can remove mtk_eint_chip_read_mask
function.

The interrupt will be re-enabled properly later on, sometimes after
mtk_eint_do_resume, when the driver is ready to handle it.

Fixes: 58a5e1b64b ("pinctrl: mediatek: Implement wake handler and suspend resume")
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Acked-by: Sean Wang <sean.wang@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-06-27 12:22:11 +01:00

498 lines
12 KiB
C
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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2014-2018 MediaTek Inc.
/*
* Library for MediaTek External Interrupt Support
*
* Author: Maoguang Meng <maoguang.meng@mediatek.com>
* Sean Wang <sean.wang@mediatek.com>
*
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include "mtk-eint.h"
#define MTK_EINT_EDGE_SENSITIVE 0
#define MTK_EINT_LEVEL_SENSITIVE 1
#define MTK_EINT_DBNC_SET_DBNC_BITS 4
#define MTK_EINT_DBNC_RST_BIT (0x1 << 1)
#define MTK_EINT_DBNC_SET_EN (0x1 << 0)
static const struct mtk_eint_regs mtk_generic_eint_regs = {
.stat = 0x000,
.ack = 0x040,
.mask = 0x080,
.mask_set = 0x0c0,
.mask_clr = 0x100,
.sens = 0x140,
.sens_set = 0x180,
.sens_clr = 0x1c0,
.soft = 0x200,
.soft_set = 0x240,
.soft_clr = 0x280,
.pol = 0x300,
.pol_set = 0x340,
.pol_clr = 0x380,
.dom_en = 0x400,
.dbnc_ctrl = 0x500,
.dbnc_set = 0x600,
.dbnc_clr = 0x700,
};
static void __iomem *mtk_eint_get_offset(struct mtk_eint *eint,
unsigned int eint_num,
unsigned int offset)
{
unsigned int eint_base = 0;
void __iomem *reg;
if (eint_num >= eint->hw->ap_num)
eint_base = eint->hw->ap_num;
reg = eint->base + offset + ((eint_num - eint_base) / 32) * 4;
return reg;
}
static unsigned int mtk_eint_can_en_debounce(struct mtk_eint *eint,
unsigned int eint_num)
{
unsigned int sens;
unsigned int bit = BIT(eint_num % 32);
void __iomem *reg = mtk_eint_get_offset(eint, eint_num,
eint->regs->sens);
if (readl(reg) & bit)
sens = MTK_EINT_LEVEL_SENSITIVE;
else
sens = MTK_EINT_EDGE_SENSITIVE;
if (eint_num < eint->hw->db_cnt && sens != MTK_EINT_EDGE_SENSITIVE)
return 1;
else
return 0;
}
static int mtk_eint_flip_edge(struct mtk_eint *eint, int hwirq)
{
int start_level, curr_level;
unsigned int reg_offset;
u32 mask = BIT(hwirq & 0x1f);
u32 port = (hwirq >> 5) & eint->hw->port_mask;
void __iomem *reg = eint->base + (port << 2);
curr_level = eint->gpio_xlate->get_gpio_state(eint->pctl, hwirq);
do {
start_level = curr_level;
if (start_level)
reg_offset = eint->regs->pol_clr;
else
reg_offset = eint->regs->pol_set;
writel(mask, reg + reg_offset);
curr_level = eint->gpio_xlate->get_gpio_state(eint->pctl,
hwirq);
} while (start_level != curr_level);
return start_level;
}
static void mtk_eint_mask(struct irq_data *d)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
u32 mask = BIT(d->hwirq & 0x1f);
void __iomem *reg = mtk_eint_get_offset(eint, d->hwirq,
eint->regs->mask_set);
eint->cur_mask[d->hwirq >> 5] &= ~mask;
writel(mask, reg);
}
static void mtk_eint_unmask(struct irq_data *d)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
u32 mask = BIT(d->hwirq & 0x1f);
void __iomem *reg = mtk_eint_get_offset(eint, d->hwirq,
eint->regs->mask_clr);
eint->cur_mask[d->hwirq >> 5] |= mask;
writel(mask, reg);
if (eint->dual_edge[d->hwirq])
mtk_eint_flip_edge(eint, d->hwirq);
}
static unsigned int mtk_eint_get_mask(struct mtk_eint *eint,
unsigned int eint_num)
{
unsigned int bit = BIT(eint_num % 32);
void __iomem *reg = mtk_eint_get_offset(eint, eint_num,
eint->regs->mask);
return !!(readl(reg) & bit);
}
static void mtk_eint_ack(struct irq_data *d)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
u32 mask = BIT(d->hwirq & 0x1f);
void __iomem *reg = mtk_eint_get_offset(eint, d->hwirq,
eint->regs->ack);
writel(mask, reg);
}
static int mtk_eint_set_type(struct irq_data *d, unsigned int type)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
u32 mask = BIT(d->hwirq & 0x1f);
void __iomem *reg;
if (((type & IRQ_TYPE_EDGE_BOTH) && (type & IRQ_TYPE_LEVEL_MASK)) ||
((type & IRQ_TYPE_LEVEL_MASK) == IRQ_TYPE_LEVEL_MASK)) {
dev_err(eint->dev,
"Can't configure IRQ%d (EINT%lu) for type 0x%X\n",
d->irq, d->hwirq, type);
return -EINVAL;
}
if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
eint->dual_edge[d->hwirq] = 1;
else
eint->dual_edge[d->hwirq] = 0;
if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING)) {
reg = mtk_eint_get_offset(eint, d->hwirq, eint->regs->pol_clr);
writel(mask, reg);
} else {
reg = mtk_eint_get_offset(eint, d->hwirq, eint->regs->pol_set);
writel(mask, reg);
}
if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) {
reg = mtk_eint_get_offset(eint, d->hwirq, eint->regs->sens_clr);
writel(mask, reg);
} else {
reg = mtk_eint_get_offset(eint, d->hwirq, eint->regs->sens_set);
writel(mask, reg);
}
if (eint->dual_edge[d->hwirq])
mtk_eint_flip_edge(eint, d->hwirq);
return 0;
}
static int mtk_eint_irq_set_wake(struct irq_data *d, unsigned int on)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
int shift = d->hwirq & 0x1f;
int reg = d->hwirq >> 5;
if (on)
eint->wake_mask[reg] |= BIT(shift);
else
eint->wake_mask[reg] &= ~BIT(shift);
return 0;
}
static void mtk_eint_chip_write_mask(const struct mtk_eint *eint,
void __iomem *base, u32 *buf)
{
int port;
void __iomem *reg;
for (port = 0; port < eint->hw->ports; port++) {
reg = base + (port << 2);
writel_relaxed(~buf[port], reg + eint->regs->mask_set);
writel_relaxed(buf[port], reg + eint->regs->mask_clr);
}
}
static int mtk_eint_irq_request_resources(struct irq_data *d)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
struct gpio_chip *gpio_c;
unsigned int gpio_n;
int err;
err = eint->gpio_xlate->get_gpio_n(eint->pctl, d->hwirq,
&gpio_n, &gpio_c);
if (err < 0) {
dev_err(eint->dev, "Can not find pin\n");
return err;
}
err = gpiochip_lock_as_irq(gpio_c, gpio_n);
if (err < 0) {
dev_err(eint->dev, "unable to lock HW IRQ %lu for IRQ\n",
irqd_to_hwirq(d));
return err;
}
err = eint->gpio_xlate->set_gpio_as_eint(eint->pctl, d->hwirq);
if (err < 0) {
dev_err(eint->dev, "Can not eint mode\n");
return err;
}
return 0;
}
static void mtk_eint_irq_release_resources(struct irq_data *d)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
struct gpio_chip *gpio_c;
unsigned int gpio_n;
eint->gpio_xlate->get_gpio_n(eint->pctl, d->hwirq, &gpio_n,
&gpio_c);
gpiochip_unlock_as_irq(gpio_c, gpio_n);
}
static struct irq_chip mtk_eint_irq_chip = {
.name = "mt-eint",
.irq_disable = mtk_eint_mask,
.irq_mask = mtk_eint_mask,
.irq_unmask = mtk_eint_unmask,
.irq_ack = mtk_eint_ack,
.irq_set_type = mtk_eint_set_type,
.irq_set_wake = mtk_eint_irq_set_wake,
.irq_request_resources = mtk_eint_irq_request_resources,
.irq_release_resources = mtk_eint_irq_release_resources,
};
static unsigned int mtk_eint_hw_init(struct mtk_eint *eint)
{
void __iomem *reg = eint->base + eint->regs->dom_en;
unsigned int i;
for (i = 0; i < eint->hw->ap_num; i += 32) {
writel(0xffffffff, reg);
reg += 4;
}
return 0;
}
static inline void
mtk_eint_debounce_process(struct mtk_eint *eint, int index)
{
unsigned int rst, ctrl_offset;
unsigned int bit, dbnc;
ctrl_offset = (index / 4) * 4 + eint->regs->dbnc_ctrl;
dbnc = readl(eint->base + ctrl_offset);
bit = MTK_EINT_DBNC_SET_EN << ((index % 4) * 8);
if ((bit & dbnc) > 0) {
ctrl_offset = (index / 4) * 4 + eint->regs->dbnc_set;
rst = MTK_EINT_DBNC_RST_BIT << ((index % 4) * 8);
writel(rst, eint->base + ctrl_offset);
}
}
static void mtk_eint_irq_handler(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct mtk_eint *eint = irq_desc_get_handler_data(desc);
unsigned int status, eint_num;
int offset, mask_offset, index, virq;
void __iomem *reg = mtk_eint_get_offset(eint, 0, eint->regs->stat);
int dual_edge, start_level, curr_level;
chained_irq_enter(chip, desc);
for (eint_num = 0; eint_num < eint->hw->ap_num; eint_num += 32,
reg += 4) {
status = readl(reg);
while (status) {
offset = __ffs(status);
mask_offset = eint_num >> 5;
index = eint_num + offset;
virq = irq_find_mapping(eint->domain, index);
status &= ~BIT(offset);
/*
* If we get an interrupt on pin that was only required
* for wake (but no real interrupt requested), mask the
* interrupt (as would mtk_eint_resume do anyway later
* in the resume sequence).
*/
if (eint->wake_mask[mask_offset] & BIT(offset) &&
!(eint->cur_mask[mask_offset] & BIT(offset))) {
writel_relaxed(BIT(offset), reg -
eint->regs->stat +
eint->regs->mask_set);
}
dual_edge = eint->dual_edge[index];
if (dual_edge) {
/*
* Clear soft-irq in case we raised it last
* time.
*/
writel(BIT(offset), reg - eint->regs->stat +
eint->regs->soft_clr);
start_level =
eint->gpio_xlate->get_gpio_state(eint->pctl,
index);
}
generic_handle_irq(virq);
if (dual_edge) {
curr_level = mtk_eint_flip_edge(eint, index);
/*
* If level changed, we might lost one edge
* interrupt, raised it through soft-irq.
*/
if (start_level != curr_level)
writel(BIT(offset), reg -
eint->regs->stat +
eint->regs->soft_set);
}
if (index < eint->hw->db_cnt)
mtk_eint_debounce_process(eint, index);
}
}
chained_irq_exit(chip, desc);
}
int mtk_eint_do_suspend(struct mtk_eint *eint)
{
mtk_eint_chip_write_mask(eint, eint->base, eint->wake_mask);
return 0;
}
int mtk_eint_do_resume(struct mtk_eint *eint)
{
mtk_eint_chip_write_mask(eint, eint->base, eint->cur_mask);
return 0;
}
int mtk_eint_set_debounce(struct mtk_eint *eint, unsigned long eint_num,
unsigned int debounce)
{
int virq, eint_offset;
unsigned int set_offset, bit, clr_bit, clr_offset, rst, i, unmask,
dbnc;
static const unsigned int debounce_time[] = {500, 1000, 16000, 32000,
64000, 128000, 256000};
struct irq_data *d;
virq = irq_find_mapping(eint->domain, eint_num);
eint_offset = (eint_num % 4) * 8;
d = irq_get_irq_data(virq);
set_offset = (eint_num / 4) * 4 + eint->regs->dbnc_set;
clr_offset = (eint_num / 4) * 4 + eint->regs->dbnc_clr;
if (!mtk_eint_can_en_debounce(eint, eint_num))
return -EINVAL;
dbnc = ARRAY_SIZE(debounce_time);
for (i = 0; i < ARRAY_SIZE(debounce_time); i++) {
if (debounce <= debounce_time[i]) {
dbnc = i;
break;
}
}
if (!mtk_eint_get_mask(eint, eint_num)) {
mtk_eint_mask(d);
unmask = 1;
} else {
unmask = 0;
}
clr_bit = 0xff << eint_offset;
writel(clr_bit, eint->base + clr_offset);
bit = ((dbnc << MTK_EINT_DBNC_SET_DBNC_BITS) | MTK_EINT_DBNC_SET_EN) <<
eint_offset;
rst = MTK_EINT_DBNC_RST_BIT << eint_offset;
writel(rst | bit, eint->base + set_offset);
/*
* Delay a while (more than 2T) to wait for hw debounce counter reset
* work correctly.
*/
udelay(1);
if (unmask == 1)
mtk_eint_unmask(d);
return 0;
}
int mtk_eint_find_irq(struct mtk_eint *eint, unsigned long eint_n)
{
int irq;
irq = irq_find_mapping(eint->domain, eint_n);
if (!irq)
return -EINVAL;
return irq;
}
int mtk_eint_do_init(struct mtk_eint *eint)
{
int i;
/* If clients don't assign a specific regs, let's use generic one */
if (!eint->regs)
eint->regs = &mtk_generic_eint_regs;
eint->wake_mask = devm_kcalloc(eint->dev, eint->hw->ports,
sizeof(*eint->wake_mask), GFP_KERNEL);
if (!eint->wake_mask)
return -ENOMEM;
eint->cur_mask = devm_kcalloc(eint->dev, eint->hw->ports,
sizeof(*eint->cur_mask), GFP_KERNEL);
if (!eint->cur_mask)
return -ENOMEM;
eint->dual_edge = devm_kcalloc(eint->dev, eint->hw->ap_num,
sizeof(int), GFP_KERNEL);
if (!eint->dual_edge)
return -ENOMEM;
eint->domain = irq_domain_add_linear(eint->dev->of_node,
eint->hw->ap_num,
&irq_domain_simple_ops, NULL);
if (!eint->domain)
return -ENOMEM;
mtk_eint_hw_init(eint);
for (i = 0; i < eint->hw->ap_num; i++) {
int virq = irq_create_mapping(eint->domain, i);
irq_set_chip_and_handler(virq, &mtk_eint_irq_chip,
handle_level_irq);
irq_set_chip_data(virq, eint);
}
irq_set_chained_handler_and_data(eint->irq, mtk_eint_irq_handler,
eint);
return 0;
}
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