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linux-next/drivers/gpio/gpio-crystalcove.c
Hans de Goede 9a752b4c9a gpio: crystalcove: Do not write regular gpio registers for virtual GPIOs 
The Crystal Cove PMIC has 16 real GPIOs but the ACPI code for devices
with this PMIC may address up to 95 GPIOs, these extra GPIOs are
called virtual GPIOs and are used by the ACPI code as a method of
accessing various non GPIO bits of PMIC.

Commit dcdc3018d6 ("gpio: crystalcove: support virtual GPIO") added
dummy support for these to avoid a bunch of ACPI errors, but instead of
ignoring writes / reads to them by doing:

if (gpio >= CRYSTALCOVE_GPIO_NUM)
	return 0;

It accidentally introduced the following wrong check:

if (gpio > CRYSTALCOVE_VGPIO_NUM)
	return 0;

Which means that attempts by the ACPI code to access these gpios
causes some arbitrary gpio to get touched through for example
GPIO1P0CTLO + gpionr % 8.

Since we do support input/output (but not interrupts) on the 0x5e
virtual GPIO, this commit makes to_reg return -ENOTSUPP for unsupported
virtual GPIOs so as to not have to check for (gpio >= CRYSTALCOVE_GPIO_NUM
&& gpio != 0x5e) everywhere and to make it easier to add support for more
virtual GPIOs in the future.

It then adds a check for to_reg returning an error to all callers where
this may happen fixing the ACPI code accessing virtual GPIOs accidentally
causing changes to real GPIOs.

Fixes: dcdc3018d6 ("gpio: crystalcove: support virtual GPIO")
Cc: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-05-23 10:02:01 +02:00

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/*
* gpio-crystalcove.c - Intel Crystal Cove GPIO Driver
*
* Copyright (C) 2012, 2014 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Author: Yang, Bin <bin.yang@intel.com>
*/
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/seq_file.h>
#include <linux/bitops.h>
#include <linux/regmap.h>
#include <linux/mfd/intel_soc_pmic.h>
#define CRYSTALCOVE_GPIO_NUM 16
#define CRYSTALCOVE_VGPIO_NUM 95
#define UPDATE_IRQ_TYPE BIT(0)
#define UPDATE_IRQ_MASK BIT(1)
#define GPIO0IRQ 0x0b
#define GPIO1IRQ 0x0c
#define MGPIO0IRQS0 0x19
#define MGPIO1IRQS0 0x1a
#define MGPIO0IRQSX 0x1b
#define MGPIO1IRQSX 0x1c
#define GPIO0P0CTLO 0x2b
#define GPIO0P0CTLI 0x33
#define GPIO1P0CTLO 0x3b
#define GPIO1P0CTLI 0x43
#define GPIOPANELCTL 0x52
#define CTLI_INTCNT_DIS (0)
#define CTLI_INTCNT_NE (1 << 1)
#define CTLI_INTCNT_PE (2 << 1)
#define CTLI_INTCNT_BE (3 << 1)
#define CTLO_DIR_IN (0)
#define CTLO_DIR_OUT (1 << 5)
#define CTLO_DRV_CMOS (0)
#define CTLO_DRV_OD (1 << 4)
#define CTLO_DRV_REN (1 << 3)
#define CTLO_RVAL_2KDW (0)
#define CTLO_RVAL_2KUP (1 << 1)
#define CTLO_RVAL_50KDW (2 << 1)
#define CTLO_RVAL_50KUP (3 << 1)
#define CTLO_INPUT_SET (CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
#define CTLO_OUTPUT_SET (CTLO_DIR_OUT | CTLO_INPUT_SET)
enum ctrl_register {
CTRL_IN,
CTRL_OUT,
};
/**
* struct crystalcove_gpio - Crystal Cove GPIO controller
* @buslock: for bus lock/sync and unlock.
* @chip: the abstract gpio_chip structure.
* @regmap: the regmap from the parent device.
* @update: pending IRQ setting update, to be written to the chip upon unlock.
* @intcnt_value: the Interrupt Detect value to be written.
* @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
*/
struct crystalcove_gpio {
struct mutex buslock; /* irq_bus_lock */
struct gpio_chip chip;
struct regmap *regmap;
int update;
int intcnt_value;
bool set_irq_mask;
};
static inline int to_reg(int gpio, enum ctrl_register reg_type)
{
int reg;
if (gpio >= CRYSTALCOVE_GPIO_NUM) {
/*
* Virtual GPIO called from ACPI, for now we only support
* the panel ctl.
*/
switch (gpio) {
case 0x5e:
return GPIOPANELCTL;
default:
return -EOPNOTSUPP;
}
}
if (reg_type == CTRL_IN) {
if (gpio < 8)
reg = GPIO0P0CTLI;
else
reg = GPIO1P0CTLI;
} else {
if (gpio < 8)
reg = GPIO0P0CTLO;
else
reg = GPIO1P0CTLO;
}
return reg + gpio % 8;
}
static void crystalcove_update_irq_mask(struct crystalcove_gpio *cg,
int gpio)
{
u8 mirqs0 = gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0;
int mask = BIT(gpio % 8);
if (cg->set_irq_mask)
regmap_update_bits(cg->regmap, mirqs0, mask, mask);
else
regmap_update_bits(cg->regmap, mirqs0, mask, 0);
}
static void crystalcove_update_irq_ctrl(struct crystalcove_gpio *cg, int gpio)
{
int reg = to_reg(gpio, CTRL_IN);
regmap_update_bits(cg->regmap, reg, CTLI_INTCNT_BE, cg->intcnt_value);
}
static int crystalcove_gpio_dir_in(struct gpio_chip *chip, unsigned gpio)
{
struct crystalcove_gpio *cg = gpiochip_get_data(chip);
int reg = to_reg(gpio, CTRL_OUT);
if (reg < 0)
return 0;
return regmap_write(cg->regmap, reg, CTLO_INPUT_SET);
}
static int crystalcove_gpio_dir_out(struct gpio_chip *chip, unsigned gpio,
int value)
{
struct crystalcove_gpio *cg = gpiochip_get_data(chip);
int reg = to_reg(gpio, CTRL_OUT);
if (reg < 0)
return 0;
return regmap_write(cg->regmap, reg, CTLO_OUTPUT_SET | value);
}
static int crystalcove_gpio_get(struct gpio_chip *chip, unsigned gpio)
{
struct crystalcove_gpio *cg = gpiochip_get_data(chip);
unsigned int val;
int ret, reg = to_reg(gpio, CTRL_IN);
if (reg < 0)
return 0;
ret = regmap_read(cg->regmap, reg, &val);
if (ret)
return ret;
return val & 0x1;
}
static void crystalcove_gpio_set(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct crystalcove_gpio *cg = gpiochip_get_data(chip);
int reg = to_reg(gpio, CTRL_OUT);
if (reg < 0)
return;
if (value)
regmap_update_bits(cg->regmap, reg, 1, 1);
else
regmap_update_bits(cg->regmap, reg, 1, 0);
}
static int crystalcove_irq_type(struct irq_data *data, unsigned type)
{
struct crystalcove_gpio *cg =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
if (data->hwirq >= CRYSTALCOVE_GPIO_NUM)
return 0;
switch (type) {
case IRQ_TYPE_NONE:
cg->intcnt_value = CTLI_INTCNT_DIS;
break;
case IRQ_TYPE_EDGE_BOTH:
cg->intcnt_value = CTLI_INTCNT_BE;
break;
case IRQ_TYPE_EDGE_RISING:
cg->intcnt_value = CTLI_INTCNT_PE;
break;
case IRQ_TYPE_EDGE_FALLING:
cg->intcnt_value = CTLI_INTCNT_NE;
break;
default:
return -EINVAL;
}
cg->update |= UPDATE_IRQ_TYPE;
return 0;
}
static void crystalcove_bus_lock(struct irq_data *data)
{
struct crystalcove_gpio *cg =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
mutex_lock(&cg->buslock);
}
static void crystalcove_bus_sync_unlock(struct irq_data *data)
{
struct crystalcove_gpio *cg =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
int gpio = data->hwirq;
if (cg->update & UPDATE_IRQ_TYPE)
crystalcove_update_irq_ctrl(cg, gpio);
if (cg->update & UPDATE_IRQ_MASK)
crystalcove_update_irq_mask(cg, gpio);
cg->update = 0;
mutex_unlock(&cg->buslock);
}
static void crystalcove_irq_unmask(struct irq_data *data)
{
struct crystalcove_gpio *cg =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
if (data->hwirq < CRYSTALCOVE_GPIO_NUM) {
cg->set_irq_mask = false;
cg->update |= UPDATE_IRQ_MASK;
}
}
static void crystalcove_irq_mask(struct irq_data *data)
{
struct crystalcove_gpio *cg =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
if (data->hwirq < CRYSTALCOVE_GPIO_NUM) {
cg->set_irq_mask = true;
cg->update |= UPDATE_IRQ_MASK;
}
}
static struct irq_chip crystalcove_irqchip = {
.name = "Crystal Cove",
.irq_mask = crystalcove_irq_mask,
.irq_unmask = crystalcove_irq_unmask,
.irq_set_type = crystalcove_irq_type,
.irq_bus_lock = crystalcove_bus_lock,
.irq_bus_sync_unlock = crystalcove_bus_sync_unlock,
.flags = IRQCHIP_SKIP_SET_WAKE,
};
static irqreturn_t crystalcove_gpio_irq_handler(int irq, void *data)
{
struct crystalcove_gpio *cg = data;
unsigned int p0, p1;
int pending;
int gpio;
unsigned int virq;
if (regmap_read(cg->regmap, GPIO0IRQ, &p0) ||
regmap_read(cg->regmap, GPIO1IRQ, &p1))
return IRQ_NONE;
regmap_write(cg->regmap, GPIO0IRQ, p0);
regmap_write(cg->regmap, GPIO1IRQ, p1);
pending = p0 | p1 << 8;
for (gpio = 0; gpio < CRYSTALCOVE_GPIO_NUM; gpio++) {
if (pending & BIT(gpio)) {
virq = irq_find_mapping(cg->chip.irqdomain, gpio);
handle_nested_irq(virq);
}
}
return IRQ_HANDLED;
}
static void crystalcove_gpio_dbg_show(struct seq_file *s,
struct gpio_chip *chip)
{
struct crystalcove_gpio *cg = gpiochip_get_data(chip);
int gpio, offset;
unsigned int ctlo, ctli, mirqs0, mirqsx, irq;
for (gpio = 0; gpio < CRYSTALCOVE_GPIO_NUM; gpio++) {
regmap_read(cg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
regmap_read(cg->regmap, to_reg(gpio, CTRL_IN), &ctli);
regmap_read(cg->regmap, gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0,
&mirqs0);
regmap_read(cg->regmap, gpio < 8 ? MGPIO0IRQSX : MGPIO1IRQSX,
&mirqsx);
regmap_read(cg->regmap, gpio < 8 ? GPIO0IRQ : GPIO1IRQ,
&irq);
offset = gpio % 8;
seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s %s\n",
gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
ctli & 0x1 ? "hi" : "lo",
ctli & CTLI_INTCNT_NE ? "fall" : " ",
ctli & CTLI_INTCNT_PE ? "rise" : " ",
ctlo,
mirqs0 & BIT(offset) ? "s0 mask " : "s0 unmask",
mirqsx & BIT(offset) ? "sx mask " : "sx unmask",
irq & BIT(offset) ? "pending" : " ");
}
}
static int crystalcove_gpio_probe(struct platform_device *pdev)
{
int irq = platform_get_irq(pdev, 0);
struct crystalcove_gpio *cg;
int retval;
struct device *dev = pdev->dev.parent;
struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
if (irq < 0)
return irq;
cg = devm_kzalloc(&pdev->dev, sizeof(*cg), GFP_KERNEL);
if (!cg)
return -ENOMEM;
platform_set_drvdata(pdev, cg);
mutex_init(&cg->buslock);
cg->chip.label = KBUILD_MODNAME;
cg->chip.direction_input = crystalcove_gpio_dir_in;
cg->chip.direction_output = crystalcove_gpio_dir_out;
cg->chip.get = crystalcove_gpio_get;
cg->chip.set = crystalcove_gpio_set;
cg->chip.base = -1;
cg->chip.ngpio = CRYSTALCOVE_VGPIO_NUM;
cg->chip.can_sleep = true;
cg->chip.parent = dev;
cg->chip.dbg_show = crystalcove_gpio_dbg_show;
cg->regmap = pmic->regmap;
retval = devm_gpiochip_add_data(&pdev->dev, &cg->chip, cg);
if (retval) {
dev_warn(&pdev->dev, "add gpio chip error: %d\n", retval);
return retval;
}
gpiochip_irqchip_add_nested(&cg->chip, &crystalcove_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
retval = request_threaded_irq(irq, NULL, crystalcove_gpio_irq_handler,
IRQF_ONESHOT, KBUILD_MODNAME, cg);
if (retval) {
dev_warn(&pdev->dev, "request irq failed: %d\n", retval);
return retval;
}
gpiochip_set_nested_irqchip(&cg->chip, &crystalcove_irqchip, irq);
return 0;
}
static int crystalcove_gpio_remove(struct platform_device *pdev)
{
struct crystalcove_gpio *cg = platform_get_drvdata(pdev);
int irq = platform_get_irq(pdev, 0);
if (irq >= 0)
free_irq(irq, cg);
return 0;
}
static struct platform_driver crystalcove_gpio_driver = {
.probe = crystalcove_gpio_probe,
.remove = crystalcove_gpio_remove,
.driver = {
.name = "crystal_cove_gpio",
},
};
module_platform_driver(crystalcove_gpio_driver);
MODULE_AUTHOR("Yang, Bin <bin.yang@intel.com>");
MODULE_DESCRIPTION("Intel Crystal Cove GPIO Driver");
MODULE_LICENSE("GPL v2");
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