blob: 5197edf1acfd5ee7ffc4d7965aa932f3975d22c6 [file] [log] [blame]
/*
* Copyright (C) ST-Ericsson SA 2010
*
* License Terms: GNU General Public License, version 2
* Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/mfd/stmpe.h>
#include <linux/seq_file.h>
/*
* These registers are modified under the irq bus lock and cached to avoid
* unnecessary writes in bus_sync_unlock.
*/
enum { REG_RE, REG_FE, REG_IE };
#define CACHE_NR_REGS 3
/* No variant has more than 24 GPIOs */
#define CACHE_NR_BANKS (24 / 8)
struct stmpe_gpio {
struct gpio_chip chip;
struct stmpe *stmpe;
struct device *dev;
struct mutex irq_lock;
u32 norequest_mask;
/* Caches of interrupt control registers for bus_lock */
u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
};
static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB] - (offset / 8);
u8 mask = 1 << (offset % 8);
int ret;
ret = stmpe_reg_read(stmpe, reg);
if (ret < 0)
return ret;
return !!(ret & mask);
}
static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB;
u8 reg = stmpe->regs[which] - (offset / 8);
u8 mask = 1 << (offset % 8);
/*
* Some variants have single register for gpio set/clear functionality.
* For them we need to write 0 to clear and 1 to set.
*/
if (stmpe->regs[STMPE_IDX_GPSR_LSB] == stmpe->regs[STMPE_IDX_GPCR_LSB])
stmpe_set_bits(stmpe, reg, mask, val ? mask : 0);
else
stmpe_reg_write(stmpe, reg, mask);
}
static int stmpe_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int val)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
u8 mask = 1 << (offset % 8);
stmpe_gpio_set(chip, offset, val);
return stmpe_set_bits(stmpe, reg, mask, mask);
}
static int stmpe_gpio_direction_input(struct gpio_chip *chip,
unsigned offset)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
u8 mask = 1 << (offset % 8);
return stmpe_set_bits(stmpe, reg, mask, 0);
}
static int stmpe_gpio_request(struct gpio_chip *chip, unsigned offset)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
if (stmpe_gpio->norequest_mask & (1 << offset))
return -EINVAL;
return stmpe_set_altfunc(stmpe, 1 << offset, STMPE_BLOCK_GPIO);
}
static struct gpio_chip template_chip = {
.label = "stmpe",
.owner = THIS_MODULE,
.direction_input = stmpe_gpio_direction_input,
.get = stmpe_gpio_get,
.direction_output = stmpe_gpio_direction_output,
.set = stmpe_gpio_set,
.request = stmpe_gpio_request,
.can_sleep = true,
};
static int stmpe_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
int offset = d->hwirq;
int regoffset = offset / 8;
int mask = 1 << (offset % 8);
if (type & IRQ_TYPE_LEVEL_LOW || type & IRQ_TYPE_LEVEL_HIGH)
return -EINVAL;
/* STMPE801 doesn't have RE and FE registers */
if (stmpe_gpio->stmpe->partnum == STMPE801)
return 0;
if (type & IRQ_TYPE_EDGE_RISING)
stmpe_gpio->regs[REG_RE][regoffset] |= mask;
else
stmpe_gpio->regs[REG_RE][regoffset] &= ~mask;
if (type & IRQ_TYPE_EDGE_FALLING)
stmpe_gpio->regs[REG_FE][regoffset] |= mask;
else
stmpe_gpio->regs[REG_FE][regoffset] &= ~mask;
return 0;
}
static void stmpe_gpio_irq_lock(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
mutex_lock(&stmpe_gpio->irq_lock);
}
static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
struct stmpe *stmpe = stmpe_gpio->stmpe;
int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
static const u8 regmap[] = {
[REG_RE] = STMPE_IDX_GPRER_LSB,
[REG_FE] = STMPE_IDX_GPFER_LSB,
[REG_IE] = STMPE_IDX_IEGPIOR_LSB,
};
int i, j;
for (i = 0; i < CACHE_NR_REGS; i++) {
/* STMPE801 doesn't have RE and FE registers */
if ((stmpe->partnum == STMPE801) &&
(i != REG_IE))
continue;
for (j = 0; j < num_banks; j++) {
u8 old = stmpe_gpio->oldregs[i][j];
u8 new = stmpe_gpio->regs[i][j];
if (new == old)
continue;
stmpe_gpio->oldregs[i][j] = new;
stmpe_reg_write(stmpe, stmpe->regs[regmap[i]] - j, new);
}
}
mutex_unlock(&stmpe_gpio->irq_lock);
}
static void stmpe_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
int offset = d->hwirq;
int regoffset = offset / 8;
int mask = 1 << (offset % 8);
stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
}
static void stmpe_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
int offset = d->hwirq;
int regoffset = offset / 8;
int mask = 1 << (offset % 8);
stmpe_gpio->regs[REG_IE][regoffset] |= mask;
}
static void stmpe_dbg_show_one(struct seq_file *s,
struct gpio_chip *gc,
unsigned offset, unsigned gpio)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
struct stmpe *stmpe = stmpe_gpio->stmpe;
const char *label = gpiochip_is_requested(gc, offset);
int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
bool val = !!stmpe_gpio_get(gc, offset);
u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
u8 mask = 1 << (offset % 8);
int ret;
u8 dir;
ret = stmpe_reg_read(stmpe, dir_reg);
if (ret < 0)
return;
dir = !!(ret & mask);
if (dir) {
seq_printf(s, " gpio-%-3d (%-20.20s) out %s",
gpio, label ?: "(none)",
val ? "hi" : "lo");
} else {
u8 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_MSB] + num_banks - 1 - (offset / 8);
u8 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB] - (offset / 8);
u8 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB] - (offset / 8);
u8 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB] - (offset / 8);
bool edge_det;
bool rise;
bool fall;
bool irqen;
ret = stmpe_reg_read(stmpe, edge_det_reg);
if (ret < 0)
return;
edge_det = !!(ret & mask);
ret = stmpe_reg_read(stmpe, rise_reg);
if (ret < 0)
return;
rise = !!(ret & mask);
ret = stmpe_reg_read(stmpe, fall_reg);
if (ret < 0)
return;
fall = !!(ret & mask);
ret = stmpe_reg_read(stmpe, irqen_reg);
if (ret < 0)
return;
irqen = !!(ret & mask);
seq_printf(s, " gpio-%-3d (%-20.20s) in %s %s %s%s%s",
gpio, label ?: "(none)",
val ? "hi" : "lo",
edge_det ? "edge-asserted" : "edge-inactive",
irqen ? "IRQ-enabled" : "",
rise ? " rising-edge-detection" : "",
fall ? " falling-edge-detection" : "");
}
}
static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc)
{
unsigned i;
unsigned gpio = gc->base;
for (i = 0; i < gc->ngpio; i++, gpio++) {
stmpe_dbg_show_one(s, gc, i, gpio);
seq_printf(s, "\n");
}
}
static struct irq_chip stmpe_gpio_irq_chip = {
.name = "stmpe-gpio",
.irq_bus_lock = stmpe_gpio_irq_lock,
.irq_bus_sync_unlock = stmpe_gpio_irq_sync_unlock,
.irq_mask = stmpe_gpio_irq_mask,
.irq_unmask = stmpe_gpio_irq_unmask,
.irq_set_type = stmpe_gpio_irq_set_type,
};
static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
{
struct stmpe_gpio *stmpe_gpio = dev;
struct stmpe *stmpe = stmpe_gpio->stmpe;
u8 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
u8 status[num_banks];
int ret;
int i;
ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
if (ret < 0)
return IRQ_NONE;
for (i = 0; i < num_banks; i++) {
int bank = num_banks - i - 1;
unsigned int enabled = stmpe_gpio->regs[REG_IE][bank];
unsigned int stat = status[i];
stat &= enabled;
if (!stat)
continue;
while (stat) {
int bit = __ffs(stat);
int line = bank * 8 + bit;
int child_irq = irq_find_mapping(stmpe_gpio->chip.irqdomain,
line);
handle_nested_irq(child_irq);
stat &= ~(1 << bit);
}
stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
/* Edge detect register is not present on 801 */
if (stmpe->partnum != STMPE801)
stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB]
+ i, status[i]);
}
return IRQ_HANDLED;
}
static int stmpe_gpio_probe(struct platform_device *pdev)
{
struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
struct device_node *np = pdev->dev.of_node;
struct stmpe_gpio *stmpe_gpio;
int ret;
int irq = 0;
irq = platform_get_irq(pdev, 0);
stmpe_gpio = kzalloc(sizeof(struct stmpe_gpio), GFP_KERNEL);
if (!stmpe_gpio)
return -ENOMEM;
mutex_init(&stmpe_gpio->irq_lock);
stmpe_gpio->dev = &pdev->dev;
stmpe_gpio->stmpe = stmpe;
stmpe_gpio->chip = template_chip;
stmpe_gpio->chip.ngpio = stmpe->num_gpios;
stmpe_gpio->chip.parent = &pdev->dev;
stmpe_gpio->chip.of_node = np;
stmpe_gpio->chip.base = -1;
if (IS_ENABLED(CONFIG_DEBUG_FS))
stmpe_gpio->chip.dbg_show = stmpe_dbg_show;
of_property_read_u32(np, "st,norequest-mask",
&stmpe_gpio->norequest_mask);
if (irq < 0)
dev_info(&pdev->dev,
"device configured in no-irq mode: "
"irqs are not available\n");
ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
if (ret)
goto out_free;
ret = gpiochip_add_data(&stmpe_gpio->chip, stmpe_gpio);
if (ret) {
dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
goto out_disable;
}
if (irq > 0) {
ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
stmpe_gpio_irq, IRQF_ONESHOT,
"stmpe-gpio", stmpe_gpio);
if (ret) {
dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
goto out_disable;
}
ret = gpiochip_irqchip_add(&stmpe_gpio->chip,
&stmpe_gpio_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(&pdev->dev,
"could not connect irqchip to gpiochip\n");
goto out_disable;
}
gpiochip_set_chained_irqchip(&stmpe_gpio->chip,
&stmpe_gpio_irq_chip,
irq,
NULL);
}
platform_set_drvdata(pdev, stmpe_gpio);
return 0;
out_disable:
stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
gpiochip_remove(&stmpe_gpio->chip);
out_free:
kfree(stmpe_gpio);
return ret;
}
static int stmpe_gpio_remove(struct platform_device *pdev)
{
struct stmpe_gpio *stmpe_gpio = platform_get_drvdata(pdev);
struct stmpe *stmpe = stmpe_gpio->stmpe;
gpiochip_remove(&stmpe_gpio->chip);
stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
kfree(stmpe_gpio);
return 0;
}
static struct platform_driver stmpe_gpio_driver = {
.driver.name = "stmpe-gpio",
.driver.owner = THIS_MODULE,
.probe = stmpe_gpio_probe,
.remove = stmpe_gpio_remove,
};
static int __init stmpe_gpio_init(void)
{
return platform_driver_register(&stmpe_gpio_driver);
}
subsys_initcall(stmpe_gpio_init);
static void __exit stmpe_gpio_exit(void)
{
platform_driver_unregister(&stmpe_gpio_driver);
}
module_exit(stmpe_gpio_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("STMPExxxx GPIO driver");
MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");